[PATCH 0/2] Add TI iodelay driver using #pinctrl-cells

[PATCH 0/2] Add TI iodelay driver using #pinctrl-cells

[Tony Lindgren]

Hi all,

Here's a respin of Nishanth's iodelay driver that I've updated to
use #pinctrl-cells and generic pinctrl group and function code.

Gary, note that this one has an iterator function that you may
be able to use too, and hopefully we can simplify things further
eventually by introducing a generic iterator.

Note that these patches are against the current pinctrl devel
branch at commit b61d1546906d ("pinctrl: single: Use generic
pinmux helpers for managing functions").

Regards,

Tony

Nishanth Menon (1):
  pinctrl: Introduce TI IOdelay configuration driver

Tony Lindgren (1):
  pinctrl: core: Make dt_free_map optional

 .../devicetree/bindings/pinctrl/ti,iodelay.txt     |  47 +
 drivers/pinctrl/Kconfig                            |   1 +
 drivers/pinctrl/Makefile                           |   1 +
 drivers/pinctrl/core.c                             |   3 -
 drivers/pinctrl/devicetree.c                       |   3 +-
 drivers/pinctrl/ti/Kconfig                         |  10 +
 drivers/pinctrl/ti/Makefile                        |   1 +
 drivers/pinctrl/ti/pinctrl-ti-iodelay.c            | 945 +++++++++++++++++++++
 8 files changed, 1007 insertions(+), 4 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/pinctrl/ti,iodelay.txt
 create mode 100644 drivers/pinctrl/ti/Kconfig
 create mode 100644 drivers/pinctrl/ti/Makefile
 create mode 100644 drivers/pinctrl/ti/pinctrl-ti-iodelay.c

-- 
2.11.0
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[PATCH 1/2] pinctrl: core: Make dt_free_map optional

[Tony Lindgren]

If the pin controller driver is using devm_kzalloc, there may not be
anything to do for dt_free_map. Let's make it optional to avoid
unncessary boilerplate code.

Signed-off-by: Tony Lindgren <tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org>
---
 drivers/pinctrl/core.c       | 3 ---
 drivers/pinctrl/devicetree.c | 3 ++-
 2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c
--- a/drivers/pinctrl/core.c
+++ b/drivers/pinctrl/core.c
@@ -1913,9 +1913,6 @@ static int pinctrl_check_ops(struct pinctrl_dev *pctldev)
 	    !ops->get_group_name)
 		return -EINVAL;
 
-	if (ops->dt_node_to_map && !ops->dt_free_map)
-		return -EINVAL;
-
 	return 0;
 }
 
diff --git a/drivers/pinctrl/devicetree.c b/drivers/pinctrl/devicetree.c
--- a/drivers/pinctrl/devicetree.c
+++ b/drivers/pinctrl/devicetree.c
@@ -42,7 +42,8 @@ static void dt_free_map(struct pinctrl_dev *pctldev,
 {
 	if (pctldev) {
 		const struct pinctrl_ops *ops = pctldev->desc->pctlops;
-		ops->dt_free_map(pctldev, map, num_maps);
+		if (ops->dt_free_map)
+			ops->dt_free_map(pctldev, map, num_maps);
 	} else {
 		/* There is no pctldev for PIN_MAP_TYPE_DUMMY_STATE */
 		kfree(map);
-- 
2.11.0
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Re: [PATCH 1/2] pinctrl: core: Make dt_free_map optional

[Linus Walleij]

On Fri, Dec 30, 2016 at 7:37 PM, Tony Lindgren <tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org> wrote:

> If the pin controller driver is using devm_kzalloc, there may not be
> anything to do for dt_free_map. Let's make it optional to avoid
> unncessary boilerplate code.
>
> Signed-off-by: Tony Lindgren <tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org>

Patch applied.

Yours,
Linus Walleij
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[PATCH 2/2] pinctrl: Introduce TI IOdelay configuration driver

[Tony Lindgren]

From: Nishanth Menon <nm@ti.com>

SoC family such as DRA7 family of processors have, in addition
to the regular muxing of pins (as done by pinctrl-single), a separate
hardware module called IODelay which is also expected to be configured.
The "IODelay" module has it's own register space that is independent
of the control module and the padconf register area.

With recent changes to the pinctrl framework, we can now support
this hardware with a reasonably minimal driver by using #pinctrl-cells,
GENERIC_PINCTRL_GROUPS and GENERIC_PINMUX_FUNCTIONS.

It is advocated strongly in TI's official documentation considering
the existing design of the DRA7 family of processors during mux or
IODelay reconfiguration, there is a potential for a significant glitch
which may cause functional impairment to certain hardware. It is
hence recommended to do as little of muxing as absolutely necessary
without I/O isolation (which can only be done in initial stages of
bootloader).

NOTE: with the system wide I/O isolation scheme present in DRA7 SoC
family, it is not reasonable to do stop all I/O operations for every
such pad configuration scheme. So, we will let it glitch when used in
this mode.

Even with the above limitation, certain functionality such as MMC has
mandatory need for IODelay reconfiguration requirements, depending on
speed of transfer. In these cases, with careful examination of usecase
involved, the expected glitch can be controlled such that it does not
impact functionality.

In short, IODelay module support as a padconf driver being introduced
here is not expected to do SoC wide I/O Isolation and is meant for
a limited subset of IODelay configuration requirements that need to
be dynamic and whose glitchy behavior will not cause functionality
failure for that interface.

IMPORTANT NOTE: we take the approach of keeping LOCK_BITs cleared
to 0x0 at all times, even when configuring Manual IO Timing Modes.
This is done by eliminating the LOCK_BIT=1 setting from Step
of the Manual IO timing Mode configuration procedure. This option
leaves the CFG_* registers unprotected from unintended writes to the
CTRL_CORE_PAD_* registers while Manual IO Timing Modes are configured.

This approach is taken to allow for a generic driver to exist in kernel
world that has to be used carefully in required usecases.

Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
[tony@atomide.com: updated to use generic pinctrl functions, added
 binding documentation, updated comments]
Signed-off-by: Tony Lindgren <tony@atomide.com>
---
 .../devicetree/bindings/pinctrl/ti,iodelay.txt     |  47 +
 drivers/pinctrl/Kconfig                            |   1 +
 drivers/pinctrl/Makefile                           |   1 +
 drivers/pinctrl/ti/Kconfig                         |  10 +
 drivers/pinctrl/ti/Makefile                        |   1 +
 drivers/pinctrl/ti/pinctrl-ti-iodelay.c            | 945 +++++++++++++++++++++
 6 files changed, 1005 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pinctrl/ti,iodelay.txt
 create mode 100644 drivers/pinctrl/ti/Kconfig
 create mode 100644 drivers/pinctrl/ti/Makefile
 create mode 100644 drivers/pinctrl/ti/pinctrl-ti-iodelay.c

diff --git a/Documentation/devicetree/bindings/pinctrl/ti,iodelay.txt b/Documentation/devicetree/bindings/pinctrl/ti,iodelay.txt
new file mode 100644
--- /dev/null
+++ b/Documentation/devicetree/bindings/pinctrl/ti,iodelay.txt
@@ -0,0 +1,47 @@
+* Pin configuration for TI IODELAY controller
+
+TI dra7 based SoCs such as am57xx have a controller for setting the IO delay
+for each pin. For most part the IO delay values are programmed by the bootloader,
+but some pins need to be configured dynamically by the kernel such as the
+MMC pins.
+
+Required Properties:
+
+  - compatible: Must be "ti,dra7-iodelay"
+  - reg: Base address and length of the memory resource used
+  - #address-cells: Number of address cells
+  - #size-cells: Size of cells
+  - #pinctrl-cells: Number of pinctrl cells, must be 2. See also
+    Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
+
+Example
+-------
+
+In the SoC specific dtsi file:
+
+	dra7_iodelay_core: padconf@4844a000 {
+		compatible = "ti,dra7-iodelay";
+		reg = <0x4844a000 0x0d1c>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+		#pinctrl-cells = <2>;
+	};
+
+In board-specific file:
+
+&dra7_iodelay_core {
+	mmc2_iodelay_3v3_conf: mmc2_iodelay_3v3_conf {
+		pinctrl-pin-array = <
+		0x18c A_DELAY_PS(0) G_DELAY_PS(120)	/* CFG_GPMC_A19_IN */
+		0x1a4 A_DELAY_PS(265) G_DELAY_PS(360)	/* CFG_GPMC_A20_IN */
+		0x1b0 A_DELAY_PS(0) G_DELAY_PS(120)	/* CFG_GPMC_A21_IN */
+		0x1bc A_DELAY_PS(0) G_DELAY_PS(120)	/* CFG_GPMC_A22_IN */
+		0x1c8 A_DELAY_PS(287) G_DELAY_PS(420)	/* CFG_GPMC_A23_IN */
+		0x1d4 A_DELAY_PS(144) G_DELAY_PS(240)	/* CFG_GPMC_A24_IN */
+		0x1e0 A_DELAY_PS(0) G_DELAY_PS(0)	/* CFG_GPMC_A25_IN */
+		0x1ec A_DELAY_PS(120) G_DELAY_PS(0)	/* CFG_GPMC_A26_IN */
+		0x1f8 A_DELAY_PS(120) G_DELAY_PS(180)	/* CFG_GPMC_A27_IN */
+		0x360 A_DELAY_PS(0) G_DELAY_PS(0)	/* CFG_GPMC_CS1_IN */
+		>;
+	};
+};
diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig
--- a/drivers/pinctrl/Kconfig
+++ b/drivers/pinctrl/Kconfig
@@ -300,6 +300,7 @@ source "drivers/pinctrl/spear/Kconfig"
 source "drivers/pinctrl/stm32/Kconfig"
 source "drivers/pinctrl/sunxi/Kconfig"
 source "drivers/pinctrl/tegra/Kconfig"
+source "drivers/pinctrl/ti/Kconfig"
 source "drivers/pinctrl/uniphier/Kconfig"
 source "drivers/pinctrl/vt8500/Kconfig"
 source "drivers/pinctrl/mediatek/Kconfig"
diff --git a/drivers/pinctrl/Makefile b/drivers/pinctrl/Makefile
--- a/drivers/pinctrl/Makefile
+++ b/drivers/pinctrl/Makefile
@@ -53,6 +53,7 @@ obj-$(CONFIG_PINCTRL_SH_PFC)	+= sh-pfc/
 obj-$(CONFIG_PINCTRL_SPEAR)	+= spear/
 obj-$(CONFIG_PINCTRL_STM32)	+= stm32/
 obj-$(CONFIG_PINCTRL_SUNXI)	+= sunxi/
+obj-y				+= ti/
 obj-$(CONFIG_PINCTRL_UNIPHIER)	+= uniphier/
 obj-$(CONFIG_ARCH_VT8500)	+= vt8500/
 obj-$(CONFIG_PINCTRL_MTK)	+= mediatek/
diff --git a/drivers/pinctrl/ti/Kconfig b/drivers/pinctrl/ti/Kconfig
new file mode 100644
--- /dev/null
+++ b/drivers/pinctrl/ti/Kconfig
@@ -0,0 +1,10 @@
+config PINCTRL_TI_IODELAY
+	tristate "TI IODelay Module pinconf driver"
+	depends on OF
+	select GENERIC_PINCTRL_GROUPS
+	select GENERIC_PINMUX_FUNCTIONS
+	select GENERIC_PINCONF
+	select REGMAP_MMIO
+	help
+	  Say Y here to support Texas Instruments' IO delay pinconf driver.
+	  IO delay module is used for the DRA7 SoC family.
diff --git a/drivers/pinctrl/ti/Makefile b/drivers/pinctrl/ti/Makefile
new file mode 100644
--- /dev/null
+++ b/drivers/pinctrl/ti/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_PINCTRL_TI_IODELAY)	+= pinctrl-ti-iodelay.o
diff --git a/drivers/pinctrl/ti/pinctrl-ti-iodelay.c b/drivers/pinctrl/ti/pinctrl-ti-iodelay.c
new file mode 100644
--- /dev/null
+++ b/drivers/pinctrl/ti/pinctrl-ti-iodelay.c
@@ -0,0 +1,945 @@
+/*
+ * Support for configuration of IO Delay module found on Texas Instruments SoCs
+ * such as DRA7
+ *
+ * Copyright (C) 2015 Texas Instruments, Inc.
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/pinctrl/pinconf.h>
+#include <linux/pinctrl/pinconf-generic.h>
+#include <linux/pinctrl/pinctrl.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+#include "../core.h"
+#include "../devicetree.h"
+
+#define DRIVER_NAME	"ti-iodelay"
+
+/**
+ * struct ti_iodelay_reg_data - Describes the registers for the iodelay instance
+ * @signature_mask: CONFIG_REG mask for the signature bits (see TRM)
+ * @signature_value: CONFIG_REG signature value to be written (see TRM)
+ * @lock_mask: CONFIG_REG mask for the lock bits (see TRM)
+ * @lock_val: CONFIG_REG lock value for the lock bits (see TRM)
+ * @unlock_val:CONFIG_REG unlock value for the lock bits (see TRM)
+ * @binary_data_coarse_mask: CONFIG_REG coarse mask (see TRM)
+ * @binary_data_fine_mask: CONFIG_REG fine mask (see TRM)
+ * @reg_refclk_offset: Refclk register offset
+ * @refclk_period_mask: Refclk mask
+ * @reg_coarse_offset: Coarse register configuration offset
+ * @coarse_delay_count_mask: Coarse delay count mask
+ * @coarse_ref_count_mask: Coarse ref count mask
+ * @reg_fine_offset: Fine register configuration offset
+ * @fine_delay_count_mask: Fine delay count mask
+ * @fine_ref_count_mask: Fine ref count mask
+ * @reg_global_lock_offset: Global iodelay module lock register offset
+ * @global_lock_mask: Lock mask
+ * @global_unlock_val: Unlock value
+ * @global_lock_val: Lock value
+ * @reg_start_offset: Offset to iodelay registers after the CONFIG_REG_0 to 8
+ * @reg_nr_per_pin: Number of iodelay registers for each pin
+ * @regmap_config: Regmap configuration for the IODelay region
+ */
+struct ti_iodelay_reg_data {
+	u32 signature_mask;
+	u32 signature_value;
+	u32 lock_mask;
+	u32 lock_val;
+	u32 unlock_val;
+	u32 binary_data_coarse_mask;
+	u32 binary_data_fine_mask;
+
+	u32 reg_refclk_offset;
+	u32 refclk_period_mask;
+
+	u32 reg_coarse_offset;
+	u32 coarse_delay_count_mask;
+	u32 coarse_ref_count_mask;
+
+	u32 reg_fine_offset;
+	u32 fine_delay_count_mask;
+	u32 fine_ref_count_mask;
+
+	u32 reg_global_lock_offset;
+	u32 global_lock_mask;
+	u32 global_unlock_val;
+	u32 global_lock_val;
+
+	u32 reg_start_offset;
+	u32 reg_nr_per_pin;
+
+	struct regmap_config *regmap_config;
+};
+
+/**
+ * struct ti_iodelay_reg_values - Computed io_reg configuration values (see TRM)
+ * @coarse_ref_count: Coarse reference count
+ * @coarse_delay_count: Coarse delay count
+ * @fine_ref_count: Fine reference count
+ * @fine_delay_count: Fine Delay count
+ * @ref_clk_period: Reference Clock period
+ * @cdpe: Coarse delay parameter
+ * @fdpe: Fine delay parameter
+ */
+struct ti_iodelay_reg_values {
+	u16 coarse_ref_count;
+	u16 coarse_delay_count;
+
+	u16 fine_ref_count;
+	u16 fine_delay_count;
+
+	u16 ref_clk_period;
+
+	u32 cdpe;
+	u32 fdpe;
+};
+
+/**
+ * struct ti_iodelay_cfg - Description of each configuration parameters
+ * @offset: Configuration register offset
+ * @a_delay: Agnostic Delay (in ps)
+ * @g_delay: Gnostic Delay (in ps)
+ */
+struct ti_iodelay_cfg {
+	u16 offset;
+	u16 a_delay;
+	u16 g_delay;
+};
+
+/**
+ * struct ti_iodelay_pingroup - Structure that describes one group
+ * @name: Name of the group
+ * @map: pinctrl map allocated for the group
+ * @cfg: configuration array for the pin (from dt)
+ * @ncfg: number of configuration values allocated
+ * @config: pinconf "Config" - currently a dummy value
+ */
+struct ti_iodelay_pingroup {
+	struct ti_iodelay_cfg *cfg;
+	int ncfg;
+	unsigned long config;
+};
+
+/**
+ * struct ti_iodelay_device - Represents information for a iodelay instance
+ * @dev: Device pointer
+ * @phys_base: Physical address base of the iodelay device
+ * @reg_base: Virtual address base of the iodelay device
+ * @regmap: Regmap for this iodelay instance
+ * @pctl: Pinctrl device
+ * @desc: pinctrl descriptor for pctl
+ * @pa: pinctrl pin wise description
+ * @names: names of the pins
+ * @reg_data: Register definition data for the IODelay instance
+ * @reg_init_conf_values: Initial configuration values.
+ */
+struct ti_iodelay_device {
+	struct device *dev;
+	unsigned long phys_base;
+	void __iomem *reg_base;
+	struct regmap *regmap;
+
+	struct pinctrl_dev *pctl;
+	struct pinctrl_desc desc;
+	struct pinctrl_pin_desc *pa;
+
+	const struct ti_iodelay_reg_data *reg_data;
+	struct ti_iodelay_reg_values reg_init_conf_values;
+};
+
+/**
+ * ti_iodelay_extract() - extract bits for a field
+ * @val: Register value
+ * @mask: Mask
+ *
+ * Return: extracted value which is appropriately shifted
+ */
+static inline u32 ti_iodelay_extract(u32 val, u32 mask)
+{
+	return (val & mask) >> __ffs(mask);
+}
+
+/**
+ * ti_iodelay_compute_dpe() - Compute equation for delay parameter
+ * @period: Period to use
+ * @ref: Reference Count
+ * @delay: Delay count
+ * @delay_m: Delay multiplier
+ *
+ * Return: Computed delay parameter
+ */
+static inline u32 ti_iodelay_compute_dpe(u16 period, u16 ref, u16 delay,
+					 u16 delay_m)
+{
+	u64 m, d;
+
+	/* Handle overflow conditions */
+	m = 10 * (u64)period * (u64)ref;
+	d = 2 * (u64)delay * (u64)delay_m;
+
+	/* Truncate result back to 32 bits */
+	return div64_u64(m, d);
+}
+
+/**
+ * ti_iodelay_pinconf_set() - Configure the pin configuration
+ * @iod: iodelay device
+ * @val: Configuration value
+ *
+ * Update the configuration register as per TRM and lockup once done.
+ * *IMPORTANT NOTE* SoC TRM does recommend doing iodelay programmation only
+ * while in Isolation. But, then, isolation also implies that every pin
+ * on the SoC (including DDR) will be isolated out. The only benefit being
+ * a glitchless configuration, However, the intent of this driver is purely
+ * to support a "glitchy" configuration where applicable.
+ *
+ * Return: 0 in case of success, else appropriate error value
+ */
+static int ti_iodelay_pinconf_set(struct ti_iodelay_device *iod,
+				  struct ti_iodelay_cfg *cfg)
+{
+	const struct ti_iodelay_reg_data *reg = iod->reg_data;
+	struct ti_iodelay_reg_values *ival = &iod->reg_init_conf_values;
+	struct device *dev = iod->dev;
+	u32 g_delay_coarse, g_delay_fine;
+	u32 a_delay_coarse, a_delay_fine;
+	u32 c_elements, f_elements;
+	u32 total_delay;
+	u32 reg_mask, reg_val, tmp_val;
+	int r;
+
+	/* NOTE: Truncation is expected in all division below */
+	g_delay_coarse = cfg->g_delay / 920;
+	g_delay_fine = ((cfg->g_delay % 920) * 10) / 60;
+
+	a_delay_coarse = cfg->a_delay / ival->cdpe;
+	a_delay_fine = ((cfg->a_delay % ival->cdpe) * 10) / ival->fdpe;
+
+	c_elements = g_delay_coarse + a_delay_coarse;
+	f_elements = (g_delay_fine + a_delay_fine) / 10;
+
+	if (f_elements > 22) {
+		total_delay = c_elements * ival->cdpe + f_elements * ival->fdpe;
+		c_elements = total_delay / ival->cdpe;
+		f_elements = (total_delay % ival->cdpe) / ival->fdpe;
+	}
+
+	reg_mask = reg->signature_mask;
+	reg_val = reg->signature_value << __ffs(reg->signature_mask);
+
+	reg_mask |= reg->binary_data_coarse_mask;
+	tmp_val = c_elements << __ffs(reg->binary_data_coarse_mask);
+	if (tmp_val & ~reg->binary_data_coarse_mask) {
+		dev_err(dev, "Masking overflow of coarse elements %08x\n",
+			tmp_val);
+		tmp_val &= reg->binary_data_coarse_mask;
+	}
+	reg_val |= tmp_val;
+
+	reg_mask |= reg->binary_data_fine_mask;
+	tmp_val = f_elements << __ffs(reg->binary_data_fine_mask);
+	if (tmp_val & ~reg->binary_data_fine_mask) {
+		dev_err(dev, "Masking overflow of fine elements %08x\n",
+			tmp_val);
+		tmp_val &= reg->binary_data_fine_mask;
+	}
+	reg_val |= tmp_val;
+
+	/*
+	 * NOTE: we leave the iodelay values unlocked - this is to work around
+	 * situations such as those found with mmc mode change.
+	 * However, this leaves open any unwarranted changes to padconf register
+	 * impacting iodelay configuration. Use with care!
+	 */
+	reg_mask |= reg->lock_mask;
+	reg_val |= reg->unlock_val << __ffs(reg->lock_mask);
+	r = regmap_update_bits(iod->regmap, cfg->offset, reg_mask, reg_val);
+
+	dev_info(dev, "Set reg 0x%x Delay(a: %d g: %d), Elements(C=%d F=%d)0x%x\n",
+		 cfg->offset, cfg->a_delay, cfg->g_delay, c_elements,
+		 f_elements, reg_val);
+
+	return r;
+}
+
+/**
+ * ti_iodelay_pinconf_init_dev() - Initialize IODelay device
+ * @iod: iodelay device
+ *
+ * Unlocks the iodelay region, computes the common parameters
+ *
+ * Return: 0 in case of success, else appropriate error value
+ */
+static int ti_iodelay_pinconf_init_dev(struct ti_iodelay_device *iod)
+{
+	const struct ti_iodelay_reg_data *reg = iod->reg_data;
+	struct device *dev = iod->dev;
+	struct ti_iodelay_reg_values *ival = &iod->reg_init_conf_values;
+	u32 val;
+	int r;
+
+	/* unlock the iodelay region */
+	r = regmap_update_bits(iod->regmap, reg->reg_global_lock_offset,
+			       reg->global_lock_mask, reg->global_unlock_val);
+	if (r)
+		return r;
+
+	/* Read up Recalibration sequence done by bootloader */
+	r = regmap_read(iod->regmap, reg->reg_refclk_offset, &val);
+	if (r)
+		return r;
+	ival->ref_clk_period = ti_iodelay_extract(val, reg->refclk_period_mask);
+	dev_dbg(dev, "refclk_period=0x%04x\n", ival->ref_clk_period);
+
+	r = regmap_read(iod->regmap, reg->reg_coarse_offset, &val);
+	if (r)
+		return r;
+	ival->coarse_ref_count =
+	    ti_iodelay_extract(val, reg->coarse_ref_count_mask);
+	ival->coarse_delay_count =
+	    ti_iodelay_extract(val, reg->coarse_delay_count_mask);
+	if (!ival->coarse_delay_count) {
+		dev_err(dev, "Invalid Coarse delay count (0) (reg=0x%08x)\n",
+			val);
+		return -EINVAL;
+	}
+	ival->cdpe = ti_iodelay_compute_dpe(ival->ref_clk_period,
+					    ival->coarse_ref_count,
+					    ival->coarse_delay_count, 88);
+	if (!ival->cdpe) {
+		dev_err(dev, "Invalid cdpe computed params = %d %d %d\n",
+			ival->ref_clk_period, ival->coarse_ref_count,
+			ival->coarse_delay_count);
+		return -EINVAL;
+	}
+	dev_dbg(iod->dev, "coarse: ref=0x%04x delay=0x%04x cdpe=0x%08x\n",
+		ival->coarse_ref_count, ival->coarse_delay_count, ival->cdpe);
+
+	r = regmap_read(iod->regmap, reg->reg_fine_offset, &val);
+	if (r)
+		return r;
+	ival->fine_ref_count =
+	    ti_iodelay_extract(val, reg->fine_ref_count_mask);
+	ival->fine_delay_count =
+	    ti_iodelay_extract(val, reg->fine_delay_count_mask);
+	if (!ival->fine_delay_count) {
+		dev_err(dev, "Invalid Fine delay count (0) (reg=0x%08x)\n",
+			val);
+		return -EINVAL;
+	}
+	ival->fdpe = ti_iodelay_compute_dpe(ival->ref_clk_period,
+					    ival->fine_ref_count,
+					    ival->fine_delay_count, 264);
+	if (!ival->fdpe) {
+		dev_err(dev, "Invalid fdpe(0) computed params = %d %d %d\n",
+			ival->ref_clk_period, ival->fine_ref_count,
+			ival->fine_delay_count);
+		return -EINVAL;
+	}
+	dev_dbg(iod->dev, "fine: ref=0x%04x delay=0x%04x fdpe=0x%08x\n",
+		ival->fine_ref_count, ival->fine_delay_count, ival->fdpe);
+
+	return 0;
+}
+
+/**
+ * ti_iodelay_pinconf_deinit_dev() - deinit the iodelay device
+ * @iod:	IODelay device
+ *
+ * Deinitialize the IODelay device (basically just lock the region back up.
+ */
+static void ti_iodelay_pinconf_deinit_dev(struct ti_iodelay_device *iod)
+{
+	const struct ti_iodelay_reg_data *reg = iod->reg_data;
+
+	/* lock the iodelay region back again */
+	regmap_update_bits(iod->regmap, reg->reg_global_lock_offset,
+			   reg->global_lock_mask, reg->global_lock_val);
+}
+
+/**
+ * ti_iodelay_get_pingroup() - Find the group mapped by a group selector
+ * @iod: iodelay device
+ * @selector: Group Selector
+ *
+ * Return: Corresponding group representing group selector
+ */
+static struct ti_iodelay_pingroup *
+ti_iodelay_get_pingroup(struct ti_iodelay_device *iod, unsigned int selector)
+{
+	struct group_desc *g;
+
+	g = pinctrl_generic_get_group(iod->pctl, selector);
+	if (!g) {
+		dev_err(iod->dev, "%s could not find pingroup %i\n", __func__,
+			selector);
+
+		return NULL;
+	}
+
+	return g->data;
+}
+
+/**
+ * ti_iodelay_pin_to_offset() - get pin register offset based on the pin index
+ * @iod: iodelay driver instance
+ * @selector: Pin index
+ */
+static unsigned int ti_iodelay_pin_to_offset(struct ti_iodelay_device *iod,
+					     unsigned int selector)
+{
+	const struct ti_iodelay_reg_data *r = iod->reg_data;
+	unsigned int offset;
+
+	offset = selector * r->regmap_config->reg_stride;
+	offset *= r->reg_nr_per_pin;
+	offset += r->reg_start_offset;
+
+	return offset;
+}
+
+/**
+ * ti_iodelay_offset_to_pin() - get a pin index based on the register offset
+ * @iod: iodelay driver instance
+ * @offset: register offset from the base
+ */
+static int ti_iodelay_offset_to_pin(struct ti_iodelay_device *iod,
+				    unsigned int offset)
+{
+	const struct ti_iodelay_reg_data *r = iod->reg_data;
+	unsigned int index;
+
+	if (offset > r->regmap_config->max_register) {
+		dev_err(iod->dev, "mux offset out of range: 0x%x (0x%x)\n",
+			offset, r->regmap_config->max_register);
+		return -EINVAL;
+	}
+
+	index = (offset - r->reg_start_offset) / r->regmap_config->reg_stride;
+	index /= r->reg_nr_per_pin;
+
+	return index;
+}
+
+/**
+ *
+ * @pctldev: Pin controller driver
+ * @np: Device node
+ * @pinctrl_spec: Parsed arguments from device tree
+ * @pins: Array of pins in the pin group
+ * @pin_index: Pin index in the pin array
+ * @data: Pin controller driver specific data
+ *
+ */
+static int ti_iodelay_node_iterator(struct pinctrl_dev *pctldev,
+				    struct device_node *np,
+				    const struct of_phandle_args *pinctrl_spec,
+				    int *pins, int pin_index, void *data)
+{
+	struct ti_iodelay_device *iod;
+	struct ti_iodelay_cfg *cfg = data;
+	const struct ti_iodelay_reg_data *r;
+	struct pinctrl_pin_desc *pd;
+	int pin;
+
+	iod = pinctrl_dev_get_drvdata(pctldev);
+	if (!iod)
+		return -EINVAL;
+
+	r = iod->reg_data;
+
+	if (pinctrl_spec->args_count < r->reg_nr_per_pin) {
+		dev_err(iod->dev, "invalid args_count for spec: %i\n",
+			pinctrl_spec->args_count);
+
+		return -EINVAL;
+	}
+
+	/* Index plus two value cells */
+	cfg[pin_index].offset = pinctrl_spec->args[0];
+	cfg[pin_index].a_delay = pinctrl_spec->args[1] & 0xffff;
+	cfg[pin_index].g_delay = pinctrl_spec->args[2] & 0xffff;
+
+	pin = ti_iodelay_offset_to_pin(iod, cfg[pin_index].offset);
+	if (pin < 0) {
+		dev_err(iod->dev, "could not add functions for %s %ux\n",
+			np->name, cfg[pin_index].offset);
+		return -ENODEV;
+	}
+	pins[pin_index] = pin;
+
+	pd = &iod->pa[pin];
+	pd->drv_data = &cfg[pin_index];
+
+	dev_dbg(iod->dev, "%s offset=%x a_delay = %d g_delay = %d\n",
+		np->name, cfg[pin_index].offset, cfg[pin_index].a_delay,
+		cfg[pin_index].g_delay);
+
+	return 0;
+}
+
+/**
+ * ti_iodelay_dt_node_to_map() - Map a device tree node to appropriate group
+ * @pctldev: pinctrl device representing IODelay device
+ * @np: Node Pointer (device tree)
+ * @map: Pinctrl Map returned back to pinctrl framework
+ * @num_maps: Number of maps (1)
+ *
+ * Maps the device tree description into a group of configuration parameters
+ * for iodelay block entry.
+ *
+ * Return: 0 in case of success, else appropriate error value
+ */
+static int ti_iodelay_dt_node_to_map(struct pinctrl_dev *pctldev,
+				     struct device_node *np,
+				     struct pinctrl_map **map,
+				     unsigned int *num_maps)
+{
+	struct ti_iodelay_device *iod;
+	struct ti_iodelay_cfg *cfg;
+	struct ti_iodelay_pingroup *g;
+	const char *name = "pinctrl-pin-array";
+	int rows, *pins, error = -EINVAL, i;
+
+	iod = pinctrl_dev_get_drvdata(pctldev);
+	if (!iod)
+		return -EINVAL;
+
+	rows = pinctrl_count_index_with_args(np, name);
+	if (rows == -EINVAL)
+		return rows;
+
+	*map = devm_kzalloc(iod->dev, sizeof(**map), GFP_KERNEL);
+	if (!*map)
+		return -ENOMEM;
+	*num_maps = 0;
+
+	g = devm_kzalloc(iod->dev, sizeof(*g), GFP_KERNEL);
+	if (!g) {
+		error = -ENOMEM;
+		goto free_map;
+	}
+
+	pins = devm_kzalloc(iod->dev, sizeof(*pins) * rows, GFP_KERNEL);
+	if (!pins)
+		goto free_group;
+
+	cfg = devm_kzalloc(iod->dev, sizeof(*cfg) * rows, GFP_KERNEL);
+	if (!cfg) {
+		error = -ENOMEM;
+		goto free_pins;
+	}
+
+	for (i = 0; i < rows; i++) {
+		struct of_phandle_args pinctrl_spec;
+
+		error = pinctrl_parse_index_with_args(np, name, i,
+						      &pinctrl_spec);
+		if (error)
+			goto free_data;
+
+		error = ti_iodelay_node_iterator(pctldev, np, &pinctrl_spec,
+						 pins, i, cfg);
+		if (error)
+			goto free_data;
+	}
+
+	g->cfg = cfg;
+	g->ncfg = i;
+	g->config = PIN_CONFIG_END;
+
+	error = pinctrl_generic_add_group(iod->pctl, np->name, pins, i, g);
+	if (error < 0)
+		goto free_data;
+
+	(*map)->type = PIN_MAP_TYPE_CONFIGS_GROUP;
+	(*map)->data.configs.group_or_pin = np->name;
+	(*map)->data.configs.configs = &g->config;
+	(*map)->data.configs.num_configs = 1;
+	*num_maps = 1;
+
+	return 0;
+
+free_data:
+	devm_kfree(iod->dev, cfg);
+free_pins:
+	devm_kfree(iod->dev, pins);
+free_group:
+	devm_kfree(iod->dev, g);
+free_map:
+	devm_kfree(iod->dev, *map);
+
+	return error;
+}
+
+/**
+ * ti_iodelay_pinconf_group_get() - Get the group configuration
+ * @pctldev: pinctrl device representing IODelay device
+ * @selector: Group selector
+ * @config: Configuration returned
+ *
+ * Return: The configuration if the group is valid, else returns -EINVAL
+ */
+static int ti_iodelay_pinconf_group_get(struct pinctrl_dev *pctldev,
+					unsigned int selector,
+					unsigned long *config)
+{
+	struct ti_iodelay_device *iod;
+	struct device *dev;
+	struct ti_iodelay_pingroup *group;
+
+	iod = pinctrl_dev_get_drvdata(pctldev);
+	dev = iod->dev;
+	group = ti_iodelay_get_pingroup(iod, selector);
+
+	if (!group)
+		return -EINVAL;
+
+	*config = group->config;
+	return 0;
+}
+
+/**
+ * ti_iodelay_pinconf_group_set() - Configure the groups of pins
+ * @pctldev: pinctrl device representing IODelay device
+ * @selector: Group selector
+ * @configs: Configurations
+ * @num_configs: Number of configurations
+ *
+ * Return: 0 if all went fine, else appropriate error value.
+ */
+static int ti_iodelay_pinconf_group_set(struct pinctrl_dev *pctldev,
+					unsigned int selector,
+					unsigned long *configs,
+					unsigned int num_configs)
+{
+	struct ti_iodelay_device *iod;
+	struct device *dev;
+	struct ti_iodelay_pingroup *group;
+	int i;
+
+	iod = pinctrl_dev_get_drvdata(pctldev);
+	dev = iod->dev;
+	group = ti_iodelay_get_pingroup(iod, selector);
+
+	if (num_configs != 1) {
+		dev_err(dev, "Unsupported number of configurations %d\n",
+			num_configs);
+		return -EINVAL;
+	}
+
+	if (*configs != PIN_CONFIG_END) {
+		dev_err(dev, "Unsupported configuration\n");
+		return -EINVAL;
+	}
+
+	for (i = 0; i < group->ncfg; i++) {
+		if (ti_iodelay_pinconf_set(iod, &group->cfg[i]))
+			return -ENOTSUPP;
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_DEBUG_FS
+static void ti_iodelay_pin_dbg_show(struct pinctrl_dev *pctldev,
+				    struct seq_file *s,
+				    unsigned int pin)
+{
+	struct ti_iodelay_device *iod;
+	struct pinctrl_pin_desc *pd;
+	struct ti_iodelay_cfg *cfg;
+	const struct ti_iodelay_reg_data *r;
+	unsigned long offset;
+	u32 in, oen, out;
+
+	iod = pinctrl_dev_get_drvdata(pctldev);
+	r = iod->reg_data;
+
+	offset = ti_iodelay_pin_to_offset(iod, pin);
+	if (pin < 0) {
+		dev_err(iod->dev, "invalid pin offset for pin%i\n", pin);
+
+		return;
+	}
+
+	pd = &iod->pa[pin];
+	cfg = pd->drv_data;
+
+	regmap_read(iod->regmap, offset, &in);
+	regmap_read(iod->regmap, offset + r->regmap_config->reg_stride, &oen);
+	regmap_read(iod->regmap, offset + r->regmap_config->reg_stride * 2,
+		    &out);
+
+	seq_printf(s, "%lx a: %i g: %i (%08x %08x %08x) %s ",
+		   iod->phys_base + offset,
+		   cfg ? cfg->a_delay : -1,
+		   cfg ? cfg->g_delay : -1,
+		   in, oen, out, DRIVER_NAME);
+}
+
+/**
+ * ti_iodelay_pinconf_group_dbg_show() - show the group information
+ * @pctldev: Show the group information
+ * @s: Sequence file
+ * @selector: Group selector
+ *
+ * Provide the configuration information of the selected group
+ */
+static void ti_iodelay_pinconf_group_dbg_show(struct pinctrl_dev *pctldev,
+					      struct seq_file *s,
+					      unsigned int selector)
+{
+	struct ti_iodelay_device *iod;
+	struct device *dev;
+	struct ti_iodelay_pingroup *group;
+	int i;
+
+	iod = pinctrl_dev_get_drvdata(pctldev);
+	dev = iod->dev;
+	group = ti_iodelay_get_pingroup(iod, selector);
+	if (!group)
+		return;
+
+	for (i = 0; i < group->ncfg; i++) {
+		struct ti_iodelay_cfg *cfg;
+		u32 reg = 0;
+
+		cfg = &group->cfg[i];
+		regmap_read(iod->regmap, cfg->offset, &reg),
+			seq_printf(s, "\n\t0x%08x = 0x%08x (%3d, %3d)",
+				   cfg->offset, reg, cfg->a_delay,
+				   cfg->g_delay);
+	}
+}
+#endif
+
+static struct pinctrl_ops ti_iodelay_pinctrl_ops = {
+	.get_groups_count = pinctrl_generic_get_group_count,
+	.get_group_name = pinctrl_generic_get_group_name,
+	.get_group_pins = pinctrl_generic_get_group_pins,
+	.pin_dbg_show = ti_iodelay_pin_dbg_show,
+	.dt_node_to_map = ti_iodelay_dt_node_to_map,
+};
+
+static struct pinconf_ops ti_iodelay_pinctrl_pinconf_ops = {
+	.pin_config_group_get = ti_iodelay_pinconf_group_get,
+	.pin_config_group_set = ti_iodelay_pinconf_group_set,
+#ifdef CONFIG_DEBUG_FS
+	.pin_config_group_dbg_show = ti_iodelay_pinconf_group_dbg_show,
+#endif
+};
+
+/**
+ * ti_iodelay_alloc_pins() - Allocate structures needed for pins for iodelay
+ * @dev: Device pointer
+ * @iod: iodelay device
+ * @base_phy: Base Physical Address
+ *
+ * Return: 0 if all went fine, else appropriate error value.
+ */
+static int ti_iodelay_alloc_pins(struct device *dev,
+				 struct ti_iodelay_device *iod, u32 base_phy)
+{
+	const struct ti_iodelay_reg_data *r = iod->reg_data;
+	struct pinctrl_pin_desc *pin;
+	u32 phy_reg;
+	int nr_pins, i;
+
+	nr_pins = ti_iodelay_offset_to_pin(iod, r->regmap_config->max_register);
+	dev_dbg(dev, "Allocating %i pins\n", nr_pins);
+
+	iod->pa = devm_kzalloc(dev, sizeof(*iod->pa) * nr_pins, GFP_KERNEL);
+	if (!iod->pa)
+		return -ENOMEM;
+
+	iod->desc.pins = iod->pa;
+	iod->desc.npins = nr_pins;
+
+	phy_reg = r->reg_start_offset + base_phy;
+
+	for (i = 0; i < nr_pins; i++, phy_reg += 4) {
+		pin = &iod->pa[i];
+		pin->number = i;
+	}
+
+	return 0;
+}
+
+static struct regmap_config dra7_iodelay_regmap_config = {
+	.reg_bits = 32,
+	.reg_stride = 4,
+	.val_bits = 32,
+	.max_register = 0xd1c,
+};
+
+static struct ti_iodelay_reg_data dra7_iodelay_data = {
+	.signature_mask = 0x0003f000,
+	.signature_value = 0x29,
+	.lock_mask = 0x00000400,
+	.lock_val = 1,
+	.unlock_val = 0,
+	.binary_data_coarse_mask = 0x000003e0,
+	.binary_data_fine_mask = 0x0000001f,
+
+	.reg_refclk_offset = 0x14,
+	.refclk_period_mask = 0xffff,
+
+	.reg_coarse_offset = 0x18,
+	.coarse_delay_count_mask = 0xffff0000,
+	.coarse_ref_count_mask = 0x0000ffff,
+
+	.reg_fine_offset = 0x1C,
+	.fine_delay_count_mask = 0xffff0000,
+	.fine_ref_count_mask = 0x0000ffff,
+
+	.reg_global_lock_offset = 0x2c,
+	.global_lock_mask = 0x0000ffff,
+	.global_unlock_val = 0x0000aaaa,
+	.global_lock_val = 0x0000aaab,
+
+	.reg_start_offset = 0x30,
+	.reg_nr_per_pin = 3,
+	.regmap_config = &dra7_iodelay_regmap_config,
+};
+
+static const struct of_device_id ti_iodelay_of_match[] = {
+	{.compatible = "ti,dra7-iodelay", .data = &dra7_iodelay_data},
+	{ /* Hopefully no more.. */ },
+};
+MODULE_DEVICE_TABLE(of, ti_iodelay_of_match);
+
+/**
+ * ti_iodelay_probe() - Standard probe
+ * @pdev: platform device
+ *
+ * Return: 0 if all went fine, else appropriate error value.
+ */
+static int ti_iodelay_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = of_node_get(dev->of_node);
+	const struct of_device_id *match;
+	struct resource *res;
+	struct ti_iodelay_device *iod;
+	int ret = 0;
+
+	if (!np) {
+		ret = -EINVAL;
+		dev_err(dev, "No OF node\n");
+		goto exit_out;
+	}
+
+	match = of_match_device(ti_iodelay_of_match, dev);
+	if (!match) {
+		ret = -EINVAL;
+		dev_err(dev, "No DATA match\n");
+		goto exit_out;
+	}
+
+	iod = devm_kzalloc(dev, sizeof(*iod), GFP_KERNEL);
+	if (!iod) {
+		ret = -ENOMEM;
+		goto exit_out;
+	}
+	iod->dev = dev;
+	iod->reg_data = match->data;
+
+	/* So far We can assume there is only 1 bank of registers */
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(dev, "Missing MEM resource\n");
+		ret = -ENODEV;
+		goto exit_out;
+	}
+
+	iod->phys_base = res->start;
+	iod->reg_base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(iod->reg_base)) {
+		ret = PTR_ERR(iod->reg_base);
+		goto exit_out;
+	}
+
+	iod->regmap = devm_regmap_init_mmio(dev, iod->reg_base,
+					    iod->reg_data->regmap_config);
+	if (IS_ERR(iod->regmap)) {
+		dev_err(dev, "Regmap MMIO init failed.\n");
+		ret = PTR_ERR(iod->regmap);
+		goto exit_out;
+	}
+
+	if (ti_iodelay_pinconf_init_dev(iod))
+		goto exit_out;
+
+	ret = ti_iodelay_alloc_pins(dev, iod, res->start);
+	if (ret)
+		goto exit_out;
+
+	iod->desc.pctlops = &ti_iodelay_pinctrl_ops;
+	/* no pinmux ops - we are pinconf */
+	iod->desc.confops = &ti_iodelay_pinctrl_pinconf_ops;
+	iod->desc.name = dev_name(dev);
+	iod->desc.owner = THIS_MODULE;
+
+	iod->pctl = pinctrl_register(&iod->desc, dev, iod);
+	if (!iod->pctl) {
+		dev_err(dev, "Failed to register pinctrl\n");
+		ret = -ENODEV;
+		goto exit_out;
+	}
+
+	platform_set_drvdata(pdev, iod);
+
+exit_out:
+	of_node_put(np);
+	return ret;
+}
+
+/**
+ * ti_iodelay_remove() - standard remove
+ * @pdev: platform device
+ *
+ * Return: 0 if all went fine, else appropriate error value.
+ */
+static int ti_iodelay_remove(struct platform_device *pdev)
+{
+	struct ti_iodelay_device *iod = platform_get_drvdata(pdev);
+
+	if (!iod)
+		return 0;
+
+	if (iod->pctl)
+		pinctrl_unregister(iod->pctl);
+
+	ti_iodelay_pinconf_deinit_dev(iod);
+
+	/* Expect other allocations to be freed by devm */
+
+	return 0;
+}
+
+static struct platform_driver ti_iodelay_driver = {
+	.probe = ti_iodelay_probe,
+	.remove = ti_iodelay_remove,
+	.driver = {
+		   .owner = THIS_MODULE,
+		   .name = DRIVER_NAME,
+		   .of_match_table = ti_iodelay_of_match,
+	},
+};
+module_platform_driver(ti_iodelay_driver);
+
+MODULE_AUTHOR("Texas Instruments, Inc.");
+MODULE_DESCRIPTION("Pinconf driver for TI's IO Delay module");
+MODULE_LICENSE("GPL v2");
-- 
2.11.0

[PATCH] ARM: dts: Add dra7 iodelay configuration and use it for MMC

[Tony Lindgren]

Add dra7 iodelay configuration and use it for MMC.

Signed-off-by: Tony Lindgren <tony@atomide.com>
---
 arch/arm/boot/dts/am57xx-beagle-x15-common.dtsi | 21 ++++++++++++++++++++-
 arch/arm/boot/dts/dra7.dtsi                     |  8 ++++++++
 include/dt-bindings/pinctrl/dra.h               |  4 ++++
 3 files changed, 32 insertions(+), 1 deletion(-)
---

And ere are the related dts changes.

diff --git a/arch/arm/boot/dts/am57xx-beagle-x15-common.dtsi b/arch/arm/boot/dts/am57xx-beagle-x15-common.dtsi
--- a/arch/arm/boot/dts/am57xx-beagle-x15-common.dtsi
+++ b/arch/arm/boot/dts/am57xx-beagle-x15-common.dtsi
@@ -190,6 +190,25 @@
 		>;
 	};
 };
+
+&dra7_iodelay_core
+{
+	mmc2_iodelay_3v3_conf: mmc2_iodelay_3v3_conf {
+		pinctrl-pin-array = <
+			0x18c A_DELAY_PS(0) G_DELAY_PS(120)	/* CFG_GPMC_A19_IN */
+			0x1a4 A_DELAY_PS(265) G_DELAY_PS(360)	/* CFG_GPMC_A20_IN */
+			0x1b0 A_DELAY_PS(0) G_DELAY_PS(120)	/* CFG_GPMC_A21_IN */
+			0x1bc A_DELAY_PS(0) G_DELAY_PS(120)	/* CFG_GPMC_A22_IN */
+			0x1c8 A_DELAY_PS(287) G_DELAY_PS(420)	/* CFG_GPMC_A23_IN */
+			0x1d4 A_DELAY_PS(144) G_DELAY_PS(240)	/* CFG_GPMC_A24_IN */
+			0x1e0 A_DELAY_PS(0) G_DELAY_PS(0)	/* CFG_GPMC_A25_IN */
+			0x1ec A_DELAY_PS(120) G_DELAY_PS(0)	/* CFG_GPMC_A26_IN */
+			0x1f8 A_DELAY_PS(120) G_DELAY_PS(180)	/* CFG_GPMC_A27_IN */
+			0x360 A_DELAY_PS(0) G_DELAY_PS(0)	/* CFG_GPMC_CS1_IN */
+		>;
+	};
+};
+
 &i2c1 {
 	status = "okay";
 	clock-frequency = <400000>;
@@ -452,7 +471,7 @@
 	status = "okay";
 
 	pinctrl-names = "default";
-	pinctrl-0 = <&mmc2_pins_default>;
+	pinctrl-0 = <&mmc2_pins_default &mmc2_iodelay_3v3_conf>;
 
 	vmmc-supply = <&vdd_3v3>;
 	bus-width = <8>;
diff --git a/arch/arm/boot/dts/dra7.dtsi b/arch/arm/boot/dts/dra7.dtsi
--- a/arch/arm/boot/dts/dra7.dtsi
+++ b/arch/arm/boot/dts/dra7.dtsi
@@ -401,6 +401,14 @@
 			reg = <0x40d00000 0x100>;
 		};
 
+		dra7_iodelay_core: padconf@4844a000 {
+			compatible = "ti,dra7-iodelay";
+			reg = <0x4844a000 0x0d1c>;
+			#address-cells = <1>;
+			#size-cells = <0>;
+			#pinctrl-cells = <2>;
+		};
+
 		sdma: dma-controller@4a056000 {
 			compatible = "ti,omap4430-sdma";
 			reg = <0x4a056000 0x1000>;
diff --git a/include/dt-bindings/pinctrl/dra.h b/include/dt-bindings/pinctrl/dra.h
--- a/include/dt-bindings/pinctrl/dra.h
+++ b/include/dt-bindings/pinctrl/dra.h
@@ -73,5 +73,9 @@
  */
 #define DRA7XX_CORE_IOPAD(pa, val)	(((pa) & 0xffff) - 0x3400) (val)
 
+/* DRA7 IODELAY configuration parameters */
+#define A_DELAY_PS(val)		((val) & 0xffff)
+#define G_DELAY_PS(val)		((val) & 0xffff)
+
 #endif
 
-- 
2.11.0

Re: [PATCH] ARM: dts: Add dra7 iodelay configuration and use it for MMC

[Linus Walleij]

On Fri, Dec 30, 2016 at 7:49 PM, Tony Lindgren <tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org> wrote:

> Add dra7 iodelay configuration and use it for MMC.
>
> Signed-off-by: Tony Lindgren <tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org>

Acked-by: Linus Walleij <linus.walleij-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>

Pls take this through the OMAP tree to ARM SoC.

Yours,
Linus Walleij
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Re: [PATCH] ARM: dts: Add dra7 iodelay configuration and use it for MMC

[Tony Lindgren]

Nishanth,

* Tony Lindgren <tony@atomide.com> [161230 10:50]:
> Add dra7 iodelay configuration and use it for MMC.

I just noticed that this patch should probably be:

From: Nishanth Menon <nm@ti.com>

I think I just added the description to the patch.

Can you please confirm and reply with your Signed-off-by
if that's the case?

Regards,

Tony


> Signed-off-by: Tony Lindgren <tony@atomide.com>
> ---
>  arch/arm/boot/dts/am57xx-beagle-x15-common.dtsi | 21 ++++++++++++++++++++-
>  arch/arm/boot/dts/dra7.dtsi                     |  8 ++++++++
>  include/dt-bindings/pinctrl/dra.h               |  4 ++++
>  3 files changed, 32 insertions(+), 1 deletion(-)
> ---
> 
> And ere are the related dts changes.
> 
> diff --git a/arch/arm/boot/dts/am57xx-beagle-x15-common.dtsi b/arch/arm/boot/dts/am57xx-beagle-x15-common.dtsi
> --- a/arch/arm/boot/dts/am57xx-beagle-x15-common.dtsi
> +++ b/arch/arm/boot/dts/am57xx-beagle-x15-common.dtsi
> @@ -190,6 +190,25 @@
>  		>;
>  	};
>  };
> +
> +&dra7_iodelay_core
> +{
> +	mmc2_iodelay_3v3_conf: mmc2_iodelay_3v3_conf {
> +		pinctrl-pin-array = <
> +			0x18c A_DELAY_PS(0) G_DELAY_PS(120)	/* CFG_GPMC_A19_IN */
> +			0x1a4 A_DELAY_PS(265) G_DELAY_PS(360)	/* CFG_GPMC_A20_IN */
> +			0x1b0 A_DELAY_PS(0) G_DELAY_PS(120)	/* CFG_GPMC_A21_IN */
> +			0x1bc A_DELAY_PS(0) G_DELAY_PS(120)	/* CFG_GPMC_A22_IN */
> +			0x1c8 A_DELAY_PS(287) G_DELAY_PS(420)	/* CFG_GPMC_A23_IN */
> +			0x1d4 A_DELAY_PS(144) G_DELAY_PS(240)	/* CFG_GPMC_A24_IN */
> +			0x1e0 A_DELAY_PS(0) G_DELAY_PS(0)	/* CFG_GPMC_A25_IN */
> +			0x1ec A_DELAY_PS(120) G_DELAY_PS(0)	/* CFG_GPMC_A26_IN */
> +			0x1f8 A_DELAY_PS(120) G_DELAY_PS(180)	/* CFG_GPMC_A27_IN */
> +			0x360 A_DELAY_PS(0) G_DELAY_PS(0)	/* CFG_GPMC_CS1_IN */
> +		>;
> +	};
> +};
> +
>  &i2c1 {
>  	status = "okay";
>  	clock-frequency = <400000>;
> @@ -452,7 +471,7 @@
>  	status = "okay";
>  
>  	pinctrl-names = "default";
> -	pinctrl-0 = <&mmc2_pins_default>;
> +	pinctrl-0 = <&mmc2_pins_default &mmc2_iodelay_3v3_conf>;
>  
>  	vmmc-supply = <&vdd_3v3>;
>  	bus-width = <8>;
> diff --git a/arch/arm/boot/dts/dra7.dtsi b/arch/arm/boot/dts/dra7.dtsi
> --- a/arch/arm/boot/dts/dra7.dtsi
> +++ b/arch/arm/boot/dts/dra7.dtsi
> @@ -401,6 +401,14 @@
>  			reg = <0x40d00000 0x100>;
>  		};
>  
> +		dra7_iodelay_core: padconf@4844a000 {
> +			compatible = "ti,dra7-iodelay";
> +			reg = <0x4844a000 0x0d1c>;
> +			#address-cells = <1>;
> +			#size-cells = <0>;
> +			#pinctrl-cells = <2>;
> +		};
> +
>  		sdma: dma-controller@4a056000 {
>  			compatible = "ti,omap4430-sdma";
>  			reg = <0x4a056000 0x1000>;
> diff --git a/include/dt-bindings/pinctrl/dra.h b/include/dt-bindings/pinctrl/dra.h
> --- a/include/dt-bindings/pinctrl/dra.h
> +++ b/include/dt-bindings/pinctrl/dra.h
> @@ -73,5 +73,9 @@
>   */
>  #define DRA7XX_CORE_IOPAD(pa, val)	(((pa) & 0xffff) - 0x3400) (val)
>  
> +/* DRA7 IODELAY configuration parameters */
> +#define A_DELAY_PS(val)		((val) & 0xffff)
> +#define G_DELAY_PS(val)		((val) & 0xffff)
> +
>  #endif
>  
> -- 
> 2.11.0
> --
> To unsubscribe from this list: send the line "unsubscribe linux-omap" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH] ARM: dts: Add dra7 iodelay configuration and use it for MMC

[Nishanth Menon]

On 02/14/2017 12:51 PM, Tony Lindgren wrote:
> Nishanth,
>
> * Tony Lindgren <tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org> [161230 10:50]:
>> Add dra7 iodelay configuration and use it for MMC.
>
> I just noticed that this patch should probably be:
>
> From: Nishanth Menon <nm-l0cyMroinI0@public.gmane.org>
>
> I think I just added the description to the patch.
>
> Can you please confirm and reply with your Signed-off-by
> if that's the case?
>

Though I had introduced the node [ 
http://git.ti.com/ti-linux-kernel/ti-linux-kernel/commit/34661cbccc679bb8d91768bc78495e94e6d40f1f 
], the x15 values were first introduced by Kishon.

http://git.ti.com/ti-linux-kernel/ti-linux-kernel/commit/1463b1e8facb7180f5679b373411b3fbeb1608fd

personally, From or not really does'nt matter as long as we can get 
the solution in.

So, as long as it helps..
Signed-off-by: Nishanth Menon <nm-l0cyMroinI0@public.gmane.org>

>
>
>> Signed-off-by: Tony Lindgren <tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org>
>> ---
>>  arch/arm/boot/dts/am57xx-beagle-x15-common.dtsi | 21 ++++++++++++++++++++-
>>  arch/arm/boot/dts/dra7.dtsi                     |  8 ++++++++
>>  include/dt-bindings/pinctrl/dra.h               |  4 ++++
>>  3 files changed, 32 insertions(+), 1 deletion(-)
>> ---
>>
>> And ere are the related dts changes.
>>
>> diff --git a/arch/arm/boot/dts/am57xx-beagle-x15-common.dtsi b/arch/arm/boot/dts/am57xx-beagle-x15-common.dtsi
>> --- a/arch/arm/boot/dts/am57xx-beagle-x15-common.dtsi
>> +++ b/arch/arm/boot/dts/am57xx-beagle-x15-common.dtsi
>> @@ -190,6 +190,25 @@
>>  		>;
>>  	};
>>  };
>> +
>> +&dra7_iodelay_core
>> +{
>> +	mmc2_iodelay_3v3_conf: mmc2_iodelay_3v3_conf {
>> +		pinctrl-pin-array = <
>> +			0x18c A_DELAY_PS(0) G_DELAY_PS(120)	/* CFG_GPMC_A19_IN */
>> +			0x1a4 A_DELAY_PS(265) G_DELAY_PS(360)	/* CFG_GPMC_A20_IN */
>> +			0x1b0 A_DELAY_PS(0) G_DELAY_PS(120)	/* CFG_GPMC_A21_IN */
>> +			0x1bc A_DELAY_PS(0) G_DELAY_PS(120)	/* CFG_GPMC_A22_IN */
>> +			0x1c8 A_DELAY_PS(287) G_DELAY_PS(420)	/* CFG_GPMC_A23_IN */
>> +			0x1d4 A_DELAY_PS(144) G_DELAY_PS(240)	/* CFG_GPMC_A24_IN */
>> +			0x1e0 A_DELAY_PS(0) G_DELAY_PS(0)	/* CFG_GPMC_A25_IN */
>> +			0x1ec A_DELAY_PS(120) G_DELAY_PS(0)	/* CFG_GPMC_A26_IN */
>> +			0x1f8 A_DELAY_PS(120) G_DELAY_PS(180)	/* CFG_GPMC_A27_IN */
>> +			0x360 A_DELAY_PS(0) G_DELAY_PS(0)	/* CFG_GPMC_CS1_IN */
>> +		>;
>> +	};
>> +};
>> +
>>  &i2c1 {
>>  	status = "okay";
>>  	clock-frequency = <400000>;
>> @@ -452,7 +471,7 @@
>>  	status = "okay";
>>
>>  	pinctrl-names = "default";
>> -	pinctrl-0 = <&mmc2_pins_default>;
>> +	pinctrl-0 = <&mmc2_pins_default &mmc2_iodelay_3v3_conf>;
>>
>>  	vmmc-supply = <&vdd_3v3>;
>>  	bus-width = <8>;
>> diff --git a/arch/arm/boot/dts/dra7.dtsi b/arch/arm/boot/dts/dra7.dtsi
>> --- a/arch/arm/boot/dts/dra7.dtsi
>> +++ b/arch/arm/boot/dts/dra7.dtsi
>> @@ -401,6 +401,14 @@
>>  			reg = <0x40d00000 0x100>;
>>  		};
>>
>> +		dra7_iodelay_core: padconf@4844a000 {
>> +			compatible = "ti,dra7-iodelay";
>> +			reg = <0x4844a000 0x0d1c>;
>> +			#address-cells = <1>;
>> +			#size-cells = <0>;
>> +			#pinctrl-cells = <2>;
>> +		};
>> +
>>  		sdma: dma-controller@4a056000 {
>>  			compatible = "ti,omap4430-sdma";
>>  			reg = <0x4a056000 0x1000>;
>> diff --git a/include/dt-bindings/pinctrl/dra.h b/include/dt-bindings/pinctrl/dra.h
>> --- a/include/dt-bindings/pinctrl/dra.h
>> +++ b/include/dt-bindings/pinctrl/dra.h
>> @@ -73,5 +73,9 @@
>>   */
>>  #define DRA7XX_CORE_IOPAD(pa, val)	(((pa) & 0xffff) - 0x3400) (val)
>>
>> +/* DRA7 IODELAY configuration parameters */
>> +#define A_DELAY_PS(val)		((val) & 0xffff)
>> +#define G_DELAY_PS(val)		((val) & 0xffff)
>> +
>>  #endif
>>
>> --
>> 2.11.0
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-omap" in
>> the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
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-- 
Regards,
Nishanth Menon
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Re: [PATCH] ARM: dts: Add dra7 iodelay configuration and use it for MMC

[Kishon Vijay Abraham I]

Hi,

On Wednesday 15 February 2017 12:27 AM, Nishanth Menon wrote:
> On 02/14/2017 12:51 PM, Tony Lindgren wrote:
>> Nishanth,
>>
>> * Tony Lindgren <tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org> [161230 10:50]:
>>> Add dra7 iodelay configuration and use it for MMC.
>>
>> I just noticed that this patch should probably be:
>>
>> From: Nishanth Menon <nm-l0cyMroinI0@public.gmane.org>
>>
>> I think I just added the description to the patch.
>>
>> Can you please confirm and reply with your Signed-off-by
>> if that's the case?
>>
> 
> Though I had introduced the node [
> http://git.ti.com/ti-linux-kernel/ti-linux-kernel/commit/34661cbccc679bb8d91768bc78495e94e6d40f1f
> ], the x15 values were first introduced by Kishon.
> 
> http://git.ti.com/ti-linux-kernel/ti-linux-kernel/commit/1463b1e8facb7180f5679b373411b3fbeb1608fd
> 
> 
> personally, From or not really does'nt matter as long as we can get the
> solution in.
> 
> So, as long as it helps..
> Signed-off-by: Nishanth Menon <nm-l0cyMroinI0@public.gmane.org>
> 
>>
>>
>>> Signed-off-by: Tony Lindgren <tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org>
>>> ---
>>>  arch/arm/boot/dts/am57xx-beagle-x15-common.dtsi | 21 ++++++++++++++++++++-
>>>  arch/arm/boot/dts/dra7.dtsi                     |  8 ++++++++
>>>  include/dt-bindings/pinctrl/dra.h               |  4 ++++
>>>  3 files changed, 32 insertions(+), 1 deletion(-)
>>> ---
>>>
>>> And ere are the related dts changes.
>>>
>>> diff --git a/arch/arm/boot/dts/am57xx-beagle-x15-common.dtsi
>>> b/arch/arm/boot/dts/am57xx-beagle-x15-common.dtsi
>>> --- a/arch/arm/boot/dts/am57xx-beagle-x15-common.dtsi
>>> +++ b/arch/arm/boot/dts/am57xx-beagle-x15-common.dtsi
>>> @@ -190,6 +190,25 @@
>>>          >;
>>>      };
>>>  };
>>> +
>>> +&dra7_iodelay_core
>>> +{
>>> +    mmc2_iodelay_3v3_conf: mmc2_iodelay_3v3_conf {
>>> +        pinctrl-pin-array = <
>>> +            0x18c A_DELAY_PS(0) G_DELAY_PS(120)    /* CFG_GPMC_A19_IN */
>>> +            0x1a4 A_DELAY_PS(265) G_DELAY_PS(360)    /* CFG_GPMC_A20_IN */
>>> +            0x1b0 A_DELAY_PS(0) G_DELAY_PS(120)    /* CFG_GPMC_A21_IN */
>>> +            0x1bc A_DELAY_PS(0) G_DELAY_PS(120)    /* CFG_GPMC_A22_IN */
>>> +            0x1c8 A_DELAY_PS(287) G_DELAY_PS(420)    /* CFG_GPMC_A23_IN */
>>> +            0x1d4 A_DELAY_PS(144) G_DELAY_PS(240)    /* CFG_GPMC_A24_IN */
>>> +            0x1e0 A_DELAY_PS(0) G_DELAY_PS(0)    /* CFG_GPMC_A25_IN */
>>> +            0x1ec A_DELAY_PS(120) G_DELAY_PS(0)    /* CFG_GPMC_A26_IN */
>>> +            0x1f8 A_DELAY_PS(120) G_DELAY_PS(180)    /* CFG_GPMC_A27_IN */
>>> +            0x360 A_DELAY_PS(0) G_DELAY_PS(0)    /* CFG_GPMC_CS1_IN */
>>> +        >;
>>> +    };
>>> +};
>>> +
>>>  &i2c1 {
>>>      status = "okay";
>>>      clock-frequency = <400000>;
>>> @@ -452,7 +471,7 @@
>>>      status = "okay";
>>>
>>>      pinctrl-names = "default";
>>> -    pinctrl-0 = <&mmc2_pins_default>;
>>> +    pinctrl-0 = <&mmc2_pins_default &mmc2_iodelay_3v3_conf>;

I had to remove the iodelay added here based on datasheet (patch [1]).

I also wanted to confirm if "MODE_SELECT" should be added in pinctrl values
like [2] for adding manual mode iodelay because that seems to be missing in
this patch.

Thanks
Kishon

[1] ->
http://git.ti.com/cgit/cgit.cgi/ti-linux-kernel/ti-linux-kernel.git/commit/?h=ti-linux-4.9.y&id=441f799d2d15a1ed2f0a89024bf3f2fd82816dbd

[2] ->
http://git.ti.com/cgit/cgit.cgi/ti-linux-kernel/ti-linux-kernel.git/commit/?h=ti-linux-4.9.y&id=decd3b433d6485d9176ce069bd66b109fb82fe07
>>>
>>>      vmmc-supply = <&vdd_3v3>;
>>>      bus-width = <8>;
>>> diff --git a/arch/arm/boot/dts/dra7.dtsi b/arch/arm/boot/dts/dra7.dtsi
>>> --- a/arch/arm/boot/dts/dra7.dtsi
>>> +++ b/arch/arm/boot/dts/dra7.dtsi
>>> @@ -401,6 +401,14 @@
>>>              reg = <0x40d00000 0x100>;
>>>          };
>>>
>>> +        dra7_iodelay_core: padconf@4844a000 {
>>> +            compatible = "ti,dra7-iodelay";
>>> +            reg = <0x4844a000 0x0d1c>;
>>> +            #address-cells = <1>;
>>> +            #size-cells = <0>;
>>> +            #pinctrl-cells = <2>;
>>> +        };
>>> +
>>>          sdma: dma-controller@4a056000 {
>>>              compatible = "ti,omap4430-sdma";
>>>              reg = <0x4a056000 0x1000>;
>>> diff --git a/include/dt-bindings/pinctrl/dra.h
>>> b/include/dt-bindings/pinctrl/dra.h
>>> --- a/include/dt-bindings/pinctrl/dra.h
>>> +++ b/include/dt-bindings/pinctrl/dra.h
>>> @@ -73,5 +73,9 @@
>>>   */
>>>  #define DRA7XX_CORE_IOPAD(pa, val)    (((pa) & 0xffff) - 0x3400) (val)
>>>
>>> +/* DRA7 IODELAY configuration parameters */
>>> +#define A_DELAY_PS(val)        ((val) & 0xffff)
>>> +#define G_DELAY_PS(val)        ((val) & 0xffff)
>>> +
>>>  #endif
>>>
>>> -- 
>>> 2.11.0
>>> -- 
>>> To unsubscribe from this list: send the line "unsubscribe linux-omap" in
>>> the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
>>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 
> 
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Re: [PATCH] ARM: dts: Add dra7 iodelay configuration and use it for MMC

[Tony Lindgren]

* Kishon Vijay Abraham I <kishon-l0cyMroinI0@public.gmane.org> [170215 04:36]:
> On Wednesday 15 February 2017 12:27 AM, Nishanth Menon wrote:
> > On 02/14/2017 12:51 PM, Tony Lindgren wrote:
> >> Nishanth,
> >>
> >> * Tony Lindgren <tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org> [161230 10:50]:
> >>> Add dra7 iodelay configuration and use it for MMC.
> >>
> >> I just noticed that this patch should probably be:
> >>
> >> From: Nishanth Menon <nm-l0cyMroinI0@public.gmane.org>
> >>
> >> I think I just added the description to the patch.
> >>
> >> Can you please confirm and reply with your Signed-off-by
> >> if that's the case?
> >>
> > 
> > Though I had introduced the node [
> > http://git.ti.com/ti-linux-kernel/ti-linux-kernel/commit/34661cbccc679bb8d91768bc78495e94e6d40f1f
> > ], the x15 values were first introduced by Kishon.
> > 
> > http://git.ti.com/ti-linux-kernel/ti-linux-kernel/commit/1463b1e8facb7180f5679b373411b3fbeb1608fd
> > 
> > 
> > personally, From or not really does'nt matter as long as we can get the
> > solution in.
> > 
> > So, as long as it helps..
> > Signed-off-by: Nishanth Menon <nm-l0cyMroinI0@public.gmane.org>
...
> I had to remove the iodelay added here based on datasheet (patch [1]).

OK thanks for the info. So we have multiple authors and as Kishon added
the working values I suggest we credit the patch for Kishon.

> I also wanted to confirm if "MODE_SELECT" should be added in pinctrl values
> like [2] for adding manual mode iodelay because that seems to be missing in
> this patch.

Oh OK. If it's needed then yeah let's update it for that too. Can you
please check it? And then send an updated version of this patch with
"From" credited to you? Just update the description to say "Based on
earlier patches in TI Linux kernel tree done by Nishanth Menon and
Kishon Vijay Abraham I".

Regards,

Tony

> [1] ->
> http://git.ti.com/cgit/cgit.cgi/ti-linux-kernel/ti-linux-kernel.git/commit/?h=ti-linux-4.9.y&id=441f799d2d15a1ed2f0a89024bf3f2fd82816dbd
> 
> [2] ->
> http://git.ti.com/cgit/cgit.cgi/ti-linux-kernel/ti-linux-kernel.git/commit/?h=ti-linux-4.9.y&id=decd3b433d6485d9176ce069bd66b109fb82fe07
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Re: [PATCH] ARM: dts: Add dra7 iodelay configuration and use it for MMC

[Kishon Vijay Abraham I]

Hi,

On Wednesday 15 February 2017 09:20 PM, Tony Lindgren wrote:
> * Kishon Vijay Abraham I <kishon@ti.com> [170215 04:36]:
>> On Wednesday 15 February 2017 12:27 AM, Nishanth Menon wrote:
>>> On 02/14/2017 12:51 PM, Tony Lindgren wrote:
>>>> Nishanth,
>>>>
>>>> * Tony Lindgren <tony@atomide.com> [161230 10:50]:
>>>>> Add dra7 iodelay configuration and use it for MMC.
>>>>
>>>> I just noticed that this patch should probably be:
>>>>
>>>> From: Nishanth Menon <nm@ti.com>
>>>>
>>>> I think I just added the description to the patch.
>>>>
>>>> Can you please confirm and reply with your Signed-off-by
>>>> if that's the case?
>>>>
>>>
>>> Though I had introduced the node [
>>> http://git.ti.com/ti-linux-kernel/ti-linux-kernel/commit/34661cbccc679bb8d91768bc78495e94e6d40f1f
>>> ], the x15 values were first introduced by Kishon.
>>>
>>> http://git.ti.com/ti-linux-kernel/ti-linux-kernel/commit/1463b1e8facb7180f5679b373411b3fbeb1608fd
>>>
>>>
>>> personally, From or not really does'nt matter as long as we can get the
>>> solution in.
>>>
>>> So, as long as it helps..
>>> Signed-off-by: Nishanth Menon <nm@ti.com>
> ...
>> I had to remove the iodelay added here based on datasheet (patch [1]).
> 
> OK thanks for the info. So we have multiple authors and as Kishon added
> the working values I suggest we credit the patch for Kishon.
> 
>> I also wanted to confirm if "MODE_SELECT" should be added in pinctrl values
>> like [2] for adding manual mode iodelay because that seems to be missing in
>> this patch.
> 
> Oh OK. If it's needed then yeah let's update it for that too. Can you
> please check it? And then send an updated version of this patch with
> "From" credited to you? Just update the description to say "Based on
> earlier patches in TI Linux kernel tree done by Nishanth Menon and
> Kishon Vijay Abraham I".

Sure, I'll send it along with adding UHS mode support patches.

Thanks
Kishon

Re: [PATCH 2/2] pinctrl: Introduce TI IOdelay configuration driver

[kbuild test robot]

[-- Attachment #1: Type: text/plain, Size: 3592 bytes --]

Hi Nishanth,

[auto build test ERROR on pinctrl/for-next]
[also build test ERROR on v4.10-rc1 next-20161224]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Tony-Lindgren/Add-TI-iodelay-driver-using-pinctrl-cells/20161231-024542
base:   https://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl.git for-next
config: arm64-allmodconfig (attached as .config)
compiler: aarch64-linux-gnu-gcc (Debian 6.1.1-9) 6.1.1 20160705
reproduce:
        wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        make.cross ARCH=arm64 

All errors (new ones prefixed by >>):

   drivers/pinctrl/ti/pinctrl-ti-iodelay.c: In function 'ti_iodelay_get_pingroup':
>> drivers/pinctrl/ti/pinctrl-ti-iodelay.c:383:6: error: implicit declaration of function 'pinctrl_generic_get_group' [-Werror=implicit-function-declaration]
     g = pinctrl_generic_get_group(iod->pctl, selector);
         ^~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/pinctrl/ti/pinctrl-ti-iodelay.c:383:4: warning: assignment makes pointer from integer without a cast [-Wint-conversion]
     g = pinctrl_generic_get_group(iod->pctl, selector);
       ^
   drivers/pinctrl/ti/pinctrl-ti-iodelay.c:391:10: error: dereferencing pointer to incomplete type 'struct group_desc'
     return g->data;
             ^~
   drivers/pinctrl/ti/pinctrl-ti-iodelay.c: In function 'ti_iodelay_dt_node_to_map':
   drivers/pinctrl/ti/pinctrl-ti-iodelay.c:562:10: error: implicit declaration of function 'pinctrl_generic_add_group' [-Werror=implicit-function-declaration]
     error = pinctrl_generic_add_group(iod->pctl, np->name, pins, i, g);
             ^~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/pinctrl/ti/pinctrl-ti-iodelay.c: At top level:
>> drivers/pinctrl/ti/pinctrl-ti-iodelay.c:729:22: error: 'pinctrl_generic_get_group_count' undeclared here (not in a function)
     .get_groups_count = pinctrl_generic_get_group_count,
                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/pinctrl/ti/pinctrl-ti-iodelay.c:730:20: error: 'pinctrl_generic_get_group_name' undeclared here (not in a function)
     .get_group_name = pinctrl_generic_get_group_name,
                       ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/pinctrl/ti/pinctrl-ti-iodelay.c:731:20: error: 'pinctrl_generic_get_group_pins' undeclared here (not in a function)
     .get_group_pins = pinctrl_generic_get_group_pins,
                       ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/pinctrl/ti/pinctrl-ti-iodelay.c: In function 'ti_iodelay_get_pingroup':
   drivers/pinctrl/ti/pinctrl-ti-iodelay.c:392:1: warning: control reaches end of non-void function [-Wreturn-type]
    }
    ^
   cc1: some warnings being treated as errors

vim +/pinctrl_generic_get_group +383 drivers/pinctrl/ti/pinctrl-ti-iodelay.c

   377	 */
   378	static struct ti_iodelay_pingroup *
   379	ti_iodelay_get_pingroup(struct ti_iodelay_device *iod, unsigned int selector)
   380	{
   381		struct group_desc *g;
   382	
 > 383		g = pinctrl_generic_get_group(iod->pctl, selector);
   384		if (!g) {
   385			dev_err(iod->dev, "%s could not find pingroup %i\n", __func__,
   386				selector);
   387	
   388			return NULL;
   389		}
   390	
 > 391		return g->data;
   392	}
   393	
   394	/**

---
0-DAY kernel test infrastructure                Open Source Technology Center
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[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 53495 bytes --]

Re: [PATCH 2/2] pinctrl: Introduce TI IOdelay configuration driver

[Tony Lindgren]

Hi,

* kbuild test robot <lkp-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> [161231 14:53]:
> Hi Nishanth,
> 
> [auto build test ERROR on pinctrl/for-next]
> [also build test ERROR on v4.10-rc1 next-20161224]
> [if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

This patch is against pinctrl/devel as noted in the cover
letter. Next does not yet have the dependencies.

I did note another build error with COMPILE_TEST
though if DEBUG_FS is not selected, will send a fix for
that.

Regards,

Tony
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Re: [PATCH 2/2] pinctrl: Introduce TI IOdelay configuration driver

[kbuild test robot]

[-- Attachment #1: Type: text/plain, Size: 8995 bytes --]

Hi Nishanth,

[auto build test ERROR on pinctrl/for-next]
[also build test ERROR on v4.10-rc1 next-20161224]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Tony-Lindgren/Add-TI-iodelay-driver-using-pinctrl-cells/20161231-024542
base:   https://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl.git for-next
config: i386-allyesconfig (attached as .config)
compiler: gcc-6 (Debian 6.2.0-3) 6.2.0 20160901
reproduce:
        # save the attached .config to linux build tree
        make ARCH=i386 

All errors (new ones prefixed by >>):

   drivers/pinctrl/ti/pinctrl-ti-iodelay.c: In function 'ti_iodelay_get_pingroup':
   drivers/pinctrl/ti/pinctrl-ti-iodelay.c:383:6: error: implicit declaration of function 'pinctrl_generic_get_group' [-Werror=implicit-function-declaration]
     g = pinctrl_generic_get_group(iod->pctl, selector);
         ^~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/pinctrl/ti/pinctrl-ti-iodelay.c:383:4: warning: assignment makes pointer from integer without a cast [-Wint-conversion]
     g = pinctrl_generic_get_group(iod->pctl, selector);
       ^
>> drivers/pinctrl/ti/pinctrl-ti-iodelay.c:391:10: error: dereferencing pointer to incomplete type 'struct group_desc'
     return g->data;
             ^~
   drivers/pinctrl/ti/pinctrl-ti-iodelay.c: In function 'ti_iodelay_dt_node_to_map':
>> drivers/pinctrl/ti/pinctrl-ti-iodelay.c:562:10: error: implicit declaration of function 'pinctrl_generic_add_group' [-Werror=implicit-function-declaration]
     error = pinctrl_generic_add_group(iod->pctl, np->name, pins, i, g);
             ^~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/pinctrl/ti/pinctrl-ti-iodelay.c: At top level:
   drivers/pinctrl/ti/pinctrl-ti-iodelay.c:729:22: error: 'pinctrl_generic_get_group_count' undeclared here (not in a function)
     .get_groups_count = pinctrl_generic_get_group_count,
                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> drivers/pinctrl/ti/pinctrl-ti-iodelay.c:730:20: error: 'pinctrl_generic_get_group_name' undeclared here (not in a function)
     .get_group_name = pinctrl_generic_get_group_name,
                       ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> drivers/pinctrl/ti/pinctrl-ti-iodelay.c:731:20: error: 'pinctrl_generic_get_group_pins' undeclared here (not in a function)
     .get_group_pins = pinctrl_generic_get_group_pins,
                       ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/pinctrl/ti/pinctrl-ti-iodelay.c: In function 'ti_iodelay_get_pingroup':
   drivers/pinctrl/ti/pinctrl-ti-iodelay.c:392:1: warning: control reaches end of non-void function [-Wreturn-type]
    }
    ^
   cc1: some warnings being treated as errors

vim +391 drivers/pinctrl/ti/pinctrl-ti-iodelay.c

   377	 */
   378	static struct ti_iodelay_pingroup *
   379	ti_iodelay_get_pingroup(struct ti_iodelay_device *iod, unsigned int selector)
   380	{
   381		struct group_desc *g;
   382	
 > 383		g = pinctrl_generic_get_group(iod->pctl, selector);
   384		if (!g) {
   385			dev_err(iod->dev, "%s could not find pingroup %i\n", __func__,
   386				selector);
   387	
   388			return NULL;
   389		}
   390	
 > 391		return g->data;
   392	}
   393	
   394	/**
   395	 * ti_iodelay_pin_to_offset() - get pin register offset based on the pin index
   396	 * @iod: iodelay driver instance
   397	 * @selector: Pin index
   398	 */
   399	static unsigned int ti_iodelay_pin_to_offset(struct ti_iodelay_device *iod,
   400						     unsigned int selector)
   401	{
   402		const struct ti_iodelay_reg_data *r = iod->reg_data;
   403		unsigned int offset;
   404	
   405		offset = selector * r->regmap_config->reg_stride;
   406		offset *= r->reg_nr_per_pin;
   407		offset += r->reg_start_offset;
   408	
   409		return offset;
   410	}
   411	
   412	/**
   413	 * ti_iodelay_offset_to_pin() - get a pin index based on the register offset
   414	 * @iod: iodelay driver instance
   415	 * @offset: register offset from the base
   416	 */
   417	static int ti_iodelay_offset_to_pin(struct ti_iodelay_device *iod,
   418					    unsigned int offset)
   419	{
   420		const struct ti_iodelay_reg_data *r = iod->reg_data;
   421		unsigned int index;
   422	
   423		if (offset > r->regmap_config->max_register) {
   424			dev_err(iod->dev, "mux offset out of range: 0x%x (0x%x)\n",
   425				offset, r->regmap_config->max_register);
   426			return -EINVAL;
   427		}
   428	
   429		index = (offset - r->reg_start_offset) / r->regmap_config->reg_stride;
   430		index /= r->reg_nr_per_pin;
   431	
   432		return index;
   433	}
   434	
   435	/**
   436	 *
   437	 * @pctldev: Pin controller driver
   438	 * @np: Device node
   439	 * @pinctrl_spec: Parsed arguments from device tree
   440	 * @pins: Array of pins in the pin group
   441	 * @pin_index: Pin index in the pin array
   442	 * @data: Pin controller driver specific data
   443	 *
   444	 */
   445	static int ti_iodelay_node_iterator(struct pinctrl_dev *pctldev,
   446					    struct device_node *np,
   447					    const struct of_phandle_args *pinctrl_spec,
   448					    int *pins, int pin_index, void *data)
   449	{
   450		struct ti_iodelay_device *iod;
   451		struct ti_iodelay_cfg *cfg = data;
   452		const struct ti_iodelay_reg_data *r;
   453		struct pinctrl_pin_desc *pd;
   454		int pin;
   455	
   456		iod = pinctrl_dev_get_drvdata(pctldev);
   457		if (!iod)
   458			return -EINVAL;
   459	
   460		r = iod->reg_data;
   461	
   462		if (pinctrl_spec->args_count < r->reg_nr_per_pin) {
   463			dev_err(iod->dev, "invalid args_count for spec: %i\n",
   464				pinctrl_spec->args_count);
   465	
   466			return -EINVAL;
   467		}
   468	
   469		/* Index plus two value cells */
   470		cfg[pin_index].offset = pinctrl_spec->args[0];
   471		cfg[pin_index].a_delay = pinctrl_spec->args[1] & 0xffff;
   472		cfg[pin_index].g_delay = pinctrl_spec->args[2] & 0xffff;
   473	
   474		pin = ti_iodelay_offset_to_pin(iod, cfg[pin_index].offset);
   475		if (pin < 0) {
   476			dev_err(iod->dev, "could not add functions for %s %ux\n",
   477				np->name, cfg[pin_index].offset);
   478			return -ENODEV;
   479		}
   480		pins[pin_index] = pin;
   481	
   482		pd = &iod->pa[pin];
   483		pd->drv_data = &cfg[pin_index];
   484	
   485		dev_dbg(iod->dev, "%s offset=%x a_delay = %d g_delay = %d\n",
   486			np->name, cfg[pin_index].offset, cfg[pin_index].a_delay,
   487			cfg[pin_index].g_delay);
   488	
   489		return 0;
   490	}
   491	
   492	/**
   493	 * ti_iodelay_dt_node_to_map() - Map a device tree node to appropriate group
   494	 * @pctldev: pinctrl device representing IODelay device
   495	 * @np: Node Pointer (device tree)
   496	 * @map: Pinctrl Map returned back to pinctrl framework
   497	 * @num_maps: Number of maps (1)
   498	 *
   499	 * Maps the device tree description into a group of configuration parameters
   500	 * for iodelay block entry.
   501	 *
   502	 * Return: 0 in case of success, else appropriate error value
   503	 */
   504	static int ti_iodelay_dt_node_to_map(struct pinctrl_dev *pctldev,
   505					     struct device_node *np,
   506					     struct pinctrl_map **map,
   507					     unsigned int *num_maps)
   508	{
   509		struct ti_iodelay_device *iod;
   510		struct ti_iodelay_cfg *cfg;
   511		struct ti_iodelay_pingroup *g;
   512		const char *name = "pinctrl-pin-array";
   513		int rows, *pins, error = -EINVAL, i;
   514	
   515		iod = pinctrl_dev_get_drvdata(pctldev);
   516		if (!iod)
   517			return -EINVAL;
   518	
   519		rows = pinctrl_count_index_with_args(np, name);
   520		if (rows == -EINVAL)
   521			return rows;
   522	
   523		*map = devm_kzalloc(iod->dev, sizeof(**map), GFP_KERNEL);
   524		if (!*map)
   525			return -ENOMEM;
   526		*num_maps = 0;
   527	
   528		g = devm_kzalloc(iod->dev, sizeof(*g), GFP_KERNEL);
   529		if (!g) {
   530			error = -ENOMEM;
   531			goto free_map;
   532		}
   533	
   534		pins = devm_kzalloc(iod->dev, sizeof(*pins) * rows, GFP_KERNEL);
   535		if (!pins)
   536			goto free_group;
   537	
   538		cfg = devm_kzalloc(iod->dev, sizeof(*cfg) * rows, GFP_KERNEL);
   539		if (!cfg) {
   540			error = -ENOMEM;
   541			goto free_pins;
   542		}
   543	
   544		for (i = 0; i < rows; i++) {
   545			struct of_phandle_args pinctrl_spec;
   546	
   547			error = pinctrl_parse_index_with_args(np, name, i,
   548							      &pinctrl_spec);
   549			if (error)
   550				goto free_data;
   551	
   552			error = ti_iodelay_node_iterator(pctldev, np, &pinctrl_spec,
   553							 pins, i, cfg);
   554			if (error)
   555				goto free_data;
   556		}
   557	
   558		g->cfg = cfg;
   559		g->ncfg = i;
   560		g->config = PIN_CONFIG_END;
   561	
 > 562		error = pinctrl_generic_add_group(iod->pctl, np->name, pins, i, g);
   563		if (error < 0)
   564			goto free_data;
   565	

---
0-DAY kernel test infrastructure                Open Source Technology Center
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[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 57326 bytes --]

Re: [PATCH 2/2] pinctrl: Introduce TI IOdelay configuration driver

[Tony Lindgren]

* Tony Lindgren <tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org> [161230 10:38]:
> +static struct pinctrl_ops ti_iodelay_pinctrl_ops = {
> +	.get_groups_count = pinctrl_generic_get_group_count,
> +	.get_group_name = pinctrl_generic_get_group_name,
> +	.get_group_pins = pinctrl_generic_get_group_pins,
> +	.pin_dbg_show = ti_iodelay_pin_dbg_show,
> +	.dt_node_to_map = ti_iodelay_dt_node_to_map,
> +};
> +
> +static struct pinconf_ops ti_iodelay_pinctrl_pinconf_ops = {
> +	.pin_config_group_get = ti_iodelay_pinconf_group_get,
> +	.pin_config_group_set = ti_iodelay_pinconf_group_set,
> +#ifdef CONFIG_DEBUG_FS
> +	.pin_config_group_dbg_show = ti_iodelay_pinconf_group_dbg_show,
> +#endif

I noticed that .pin_dbg_show above needs ifdef CONFIG_DEBUGFS.
Updated patch below.

Regards,

Tony

8< --------------------
>From tony Mon Sep 17 00:00:00 2001
From: Nishanth Menon <nm-l0cyMroinI0@public.gmane.org>
Date: Tue, 27 Dec 2016 08:03:43 -0800
Subject: [PATCH] pinctrl: Introduce TI IOdelay configuration driver

SoC family such as DRA7 family of processors have, in addition
to the regular muxing of pins (as done by pinctrl-single), a separate
hardware module called IODelay which is also expected to be configured.
The "IODelay" module has it's own register space that is independent
of the control module and the padconf register area.

With recent changes to the pinctrl framework, we can now support
this hardware with a reasonably minimal driver by using #pinctrl-cells,
GENERIC_PINCTRL_GROUPS and GENERIC_PINMUX_FUNCTIONS.

It is advocated strongly in TI's official documentation considering
the existing design of the DRA7 family of processors during mux or
IODelay reconfiguration, there is a potential for a significant glitch
which may cause functional impairment to certain hardware. It is
hence recommended to do as little of muxing as absolutely necessary
without I/O isolation (which can only be done in initial stages of
bootloader).

NOTE: with the system wide I/O isolation scheme present in DRA7 SoC
family, it is not reasonable to do stop all I/O operations for every
such pad configuration scheme. So, we will let it glitch when used in
this mode.

Even with the above limitation, certain functionality such as MMC has
mandatory need for IODelay reconfiguration requirements, depending on
speed of transfer. In these cases, with careful examination of usecase
involved, the expected glitch can be controlled such that it does not
impact functionality.

In short, IODelay module support as a padconf driver being introduced
here is not expected to do SoC wide I/O Isolation and is meant for
a limited subset of IODelay configuration requirements that need to
be dynamic and whose glitchy behavior will not cause functionality
failure for that interface.

IMPORTANT NOTE: we take the approach of keeping LOCK_BITs cleared
to 0x0 at all times, even when configuring Manual IO Timing Modes.
This is done by eliminating the LOCK_BIT=1 setting from Step
of the Manual IO timing Mode configuration procedure. This option
leaves the CFG_* registers unprotected from unintended writes to the
CTRL_CORE_PAD_* registers while Manual IO Timing Modes are configured.

This approach is taken to allow for a generic driver to exist in kernel
world that has to be used carefully in required usecases.

Signed-off-by: Nishanth Menon <nm-l0cyMroinI0@public.gmane.org>
Signed-off-by: Lokesh Vutla <lokeshvutla-l0cyMroinI0@public.gmane.org>
[tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org: updated to use generic pinctrl functions, added
 binding documentation, updated comments]
Signed-off-by: Tony Lindgren <tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org>
---
 .../devicetree/bindings/pinctrl/ti,iodelay.txt     |  47 +
 drivers/pinctrl/Kconfig                            |   1 +
 drivers/pinctrl/Makefile                           |   1 +
 drivers/pinctrl/ti/Kconfig                         |  10 +
 drivers/pinctrl/ti/Makefile                        |   1 +
 drivers/pinctrl/ti/pinctrl-ti-iodelay.c            | 947 +++++++++++++++++++++
 6 files changed, 1007 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pinctrl/ti,iodelay.txt
 create mode 100644 drivers/pinctrl/ti/Kconfig
 create mode 100644 drivers/pinctrl/ti/Makefile
 create mode 100644 drivers/pinctrl/ti/pinctrl-ti-iodelay.c

diff --git a/Documentation/devicetree/bindings/pinctrl/ti,iodelay.txt b/Documentation/devicetree/bindings/pinctrl/ti,iodelay.txt
new file mode 100644
--- /dev/null
+++ b/Documentation/devicetree/bindings/pinctrl/ti,iodelay.txt
@@ -0,0 +1,47 @@
+* Pin configuration for TI IODELAY controller
+
+TI dra7 based SoCs such as am57xx have a controller for setting the IO delay
+for each pin. For most part the IO delay values are programmed by the bootloader,
+but some pins need to be configured dynamically by the kernel such as the
+MMC pins.
+
+Required Properties:
+
+  - compatible: Must be "ti,dra7-iodelay"
+  - reg: Base address and length of the memory resource used
+  - #address-cells: Number of address cells
+  - #size-cells: Size of cells
+  - #pinctrl-cells: Number of pinctrl cells, must be 2. See also
+    Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
+
+Example
+-------
+
+In the SoC specific dtsi file:
+
+	dra7_iodelay_core: padconf@4844a000 {
+		compatible = "ti,dra7-iodelay";
+		reg = <0x4844a000 0x0d1c>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+		#pinctrl-cells = <2>;
+	};
+
+In board-specific file:
+
+&dra7_iodelay_core {
+	mmc2_iodelay_3v3_conf: mmc2_iodelay_3v3_conf {
+		pinctrl-pin-array = <
+		0x18c A_DELAY_PS(0) G_DELAY_PS(120)	/* CFG_GPMC_A19_IN */
+		0x1a4 A_DELAY_PS(265) G_DELAY_PS(360)	/* CFG_GPMC_A20_IN */
+		0x1b0 A_DELAY_PS(0) G_DELAY_PS(120)	/* CFG_GPMC_A21_IN */
+		0x1bc A_DELAY_PS(0) G_DELAY_PS(120)	/* CFG_GPMC_A22_IN */
+		0x1c8 A_DELAY_PS(287) G_DELAY_PS(420)	/* CFG_GPMC_A23_IN */
+		0x1d4 A_DELAY_PS(144) G_DELAY_PS(240)	/* CFG_GPMC_A24_IN */
+		0x1e0 A_DELAY_PS(0) G_DELAY_PS(0)	/* CFG_GPMC_A25_IN */
+		0x1ec A_DELAY_PS(120) G_DELAY_PS(0)	/* CFG_GPMC_A26_IN */
+		0x1f8 A_DELAY_PS(120) G_DELAY_PS(180)	/* CFG_GPMC_A27_IN */
+		0x360 A_DELAY_PS(0) G_DELAY_PS(0)	/* CFG_GPMC_CS1_IN */
+		>;
+	};
+};
diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig
--- a/drivers/pinctrl/Kconfig
+++ b/drivers/pinctrl/Kconfig
@@ -300,6 +300,7 @@ source "drivers/pinctrl/spear/Kconfig"
 source "drivers/pinctrl/stm32/Kconfig"
 source "drivers/pinctrl/sunxi/Kconfig"
 source "drivers/pinctrl/tegra/Kconfig"
+source "drivers/pinctrl/ti/Kconfig"
 source "drivers/pinctrl/uniphier/Kconfig"
 source "drivers/pinctrl/vt8500/Kconfig"
 source "drivers/pinctrl/mediatek/Kconfig"
diff --git a/drivers/pinctrl/Makefile b/drivers/pinctrl/Makefile
--- a/drivers/pinctrl/Makefile
+++ b/drivers/pinctrl/Makefile
@@ -53,6 +53,7 @@ obj-$(CONFIG_PINCTRL_SH_PFC)	+= sh-pfc/
 obj-$(CONFIG_PINCTRL_SPEAR)	+= spear/
 obj-$(CONFIG_PINCTRL_STM32)	+= stm32/
 obj-$(CONFIG_PINCTRL_SUNXI)	+= sunxi/
+obj-y				+= ti/
 obj-$(CONFIG_PINCTRL_UNIPHIER)	+= uniphier/
 obj-$(CONFIG_ARCH_VT8500)	+= vt8500/
 obj-$(CONFIG_PINCTRL_MTK)	+= mediatek/
diff --git a/drivers/pinctrl/ti/Kconfig b/drivers/pinctrl/ti/Kconfig
new file mode 100644
--- /dev/null
+++ b/drivers/pinctrl/ti/Kconfig
@@ -0,0 +1,10 @@
+config PINCTRL_TI_IODELAY
+	tristate "TI IODelay Module pinconf driver"
+	depends on OF
+	select GENERIC_PINCTRL_GROUPS
+	select GENERIC_PINMUX_FUNCTIONS
+	select GENERIC_PINCONF
+	select REGMAP_MMIO
+	help
+	  Say Y here to support Texas Instruments' IO delay pinconf driver.
+	  IO delay module is used for the DRA7 SoC family.
diff --git a/drivers/pinctrl/ti/Makefile b/drivers/pinctrl/ti/Makefile
new file mode 100644
--- /dev/null
+++ b/drivers/pinctrl/ti/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_PINCTRL_TI_IODELAY)	+= pinctrl-ti-iodelay.o
diff --git a/drivers/pinctrl/ti/pinctrl-ti-iodelay.c b/drivers/pinctrl/ti/pinctrl-ti-iodelay.c
new file mode 100644
--- /dev/null
+++ b/drivers/pinctrl/ti/pinctrl-ti-iodelay.c
@@ -0,0 +1,947 @@
+/*
+ * Support for configuration of IO Delay module found on Texas Instruments SoCs
+ * such as DRA7
+ *
+ * Copyright (C) 2015 Texas Instruments, Inc.
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/pinctrl/pinconf.h>
+#include <linux/pinctrl/pinconf-generic.h>
+#include <linux/pinctrl/pinctrl.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+#include "../core.h"
+#include "../devicetree.h"
+
+#define DRIVER_NAME	"ti-iodelay"
+
+/**
+ * struct ti_iodelay_reg_data - Describes the registers for the iodelay instance
+ * @signature_mask: CONFIG_REG mask for the signature bits (see TRM)
+ * @signature_value: CONFIG_REG signature value to be written (see TRM)
+ * @lock_mask: CONFIG_REG mask for the lock bits (see TRM)
+ * @lock_val: CONFIG_REG lock value for the lock bits (see TRM)
+ * @unlock_val:CONFIG_REG unlock value for the lock bits (see TRM)
+ * @binary_data_coarse_mask: CONFIG_REG coarse mask (see TRM)
+ * @binary_data_fine_mask: CONFIG_REG fine mask (see TRM)
+ * @reg_refclk_offset: Refclk register offset
+ * @refclk_period_mask: Refclk mask
+ * @reg_coarse_offset: Coarse register configuration offset
+ * @coarse_delay_count_mask: Coarse delay count mask
+ * @coarse_ref_count_mask: Coarse ref count mask
+ * @reg_fine_offset: Fine register configuration offset
+ * @fine_delay_count_mask: Fine delay count mask
+ * @fine_ref_count_mask: Fine ref count mask
+ * @reg_global_lock_offset: Global iodelay module lock register offset
+ * @global_lock_mask: Lock mask
+ * @global_unlock_val: Unlock value
+ * @global_lock_val: Lock value
+ * @reg_start_offset: Offset to iodelay registers after the CONFIG_REG_0 to 8
+ * @reg_nr_per_pin: Number of iodelay registers for each pin
+ * @regmap_config: Regmap configuration for the IODelay region
+ */
+struct ti_iodelay_reg_data {
+	u32 signature_mask;
+	u32 signature_value;
+	u32 lock_mask;
+	u32 lock_val;
+	u32 unlock_val;
+	u32 binary_data_coarse_mask;
+	u32 binary_data_fine_mask;
+
+	u32 reg_refclk_offset;
+	u32 refclk_period_mask;
+
+	u32 reg_coarse_offset;
+	u32 coarse_delay_count_mask;
+	u32 coarse_ref_count_mask;
+
+	u32 reg_fine_offset;
+	u32 fine_delay_count_mask;
+	u32 fine_ref_count_mask;
+
+	u32 reg_global_lock_offset;
+	u32 global_lock_mask;
+	u32 global_unlock_val;
+	u32 global_lock_val;
+
+	u32 reg_start_offset;
+	u32 reg_nr_per_pin;
+
+	struct regmap_config *regmap_config;
+};
+
+/**
+ * struct ti_iodelay_reg_values - Computed io_reg configuration values (see TRM)
+ * @coarse_ref_count: Coarse reference count
+ * @coarse_delay_count: Coarse delay count
+ * @fine_ref_count: Fine reference count
+ * @fine_delay_count: Fine Delay count
+ * @ref_clk_period: Reference Clock period
+ * @cdpe: Coarse delay parameter
+ * @fdpe: Fine delay parameter
+ */
+struct ti_iodelay_reg_values {
+	u16 coarse_ref_count;
+	u16 coarse_delay_count;
+
+	u16 fine_ref_count;
+	u16 fine_delay_count;
+
+	u16 ref_clk_period;
+
+	u32 cdpe;
+	u32 fdpe;
+};
+
+/**
+ * struct ti_iodelay_cfg - Description of each configuration parameters
+ * @offset: Configuration register offset
+ * @a_delay: Agnostic Delay (in ps)
+ * @g_delay: Gnostic Delay (in ps)
+ */
+struct ti_iodelay_cfg {
+	u16 offset;
+	u16 a_delay;
+	u16 g_delay;
+};
+
+/**
+ * struct ti_iodelay_pingroup - Structure that describes one group
+ * @name: Name of the group
+ * @map: pinctrl map allocated for the group
+ * @cfg: configuration array for the pin (from dt)
+ * @ncfg: number of configuration values allocated
+ * @config: pinconf "Config" - currently a dummy value
+ */
+struct ti_iodelay_pingroup {
+	struct ti_iodelay_cfg *cfg;
+	int ncfg;
+	unsigned long config;
+};
+
+/**
+ * struct ti_iodelay_device - Represents information for a iodelay instance
+ * @dev: Device pointer
+ * @phys_base: Physical address base of the iodelay device
+ * @reg_base: Virtual address base of the iodelay device
+ * @regmap: Regmap for this iodelay instance
+ * @pctl: Pinctrl device
+ * @desc: pinctrl descriptor for pctl
+ * @pa: pinctrl pin wise description
+ * @names: names of the pins
+ * @reg_data: Register definition data for the IODelay instance
+ * @reg_init_conf_values: Initial configuration values.
+ */
+struct ti_iodelay_device {
+	struct device *dev;
+	unsigned long phys_base;
+	void __iomem *reg_base;
+	struct regmap *regmap;
+
+	struct pinctrl_dev *pctl;
+	struct pinctrl_desc desc;
+	struct pinctrl_pin_desc *pa;
+
+	const struct ti_iodelay_reg_data *reg_data;
+	struct ti_iodelay_reg_values reg_init_conf_values;
+};
+
+/**
+ * ti_iodelay_extract() - extract bits for a field
+ * @val: Register value
+ * @mask: Mask
+ *
+ * Return: extracted value which is appropriately shifted
+ */
+static inline u32 ti_iodelay_extract(u32 val, u32 mask)
+{
+	return (val & mask) >> __ffs(mask);
+}
+
+/**
+ * ti_iodelay_compute_dpe() - Compute equation for delay parameter
+ * @period: Period to use
+ * @ref: Reference Count
+ * @delay: Delay count
+ * @delay_m: Delay multiplier
+ *
+ * Return: Computed delay parameter
+ */
+static inline u32 ti_iodelay_compute_dpe(u16 period, u16 ref, u16 delay,
+					 u16 delay_m)
+{
+	u64 m, d;
+
+	/* Handle overflow conditions */
+	m = 10 * (u64)period * (u64)ref;
+	d = 2 * (u64)delay * (u64)delay_m;
+
+	/* Truncate result back to 32 bits */
+	return div64_u64(m, d);
+}
+
+/**
+ * ti_iodelay_pinconf_set() - Configure the pin configuration
+ * @iod: iodelay device
+ * @val: Configuration value
+ *
+ * Update the configuration register as per TRM and lockup once done.
+ * *IMPORTANT NOTE* SoC TRM does recommend doing iodelay programmation only
+ * while in Isolation. But, then, isolation also implies that every pin
+ * on the SoC (including DDR) will be isolated out. The only benefit being
+ * a glitchless configuration, However, the intent of this driver is purely
+ * to support a "glitchy" configuration where applicable.
+ *
+ * Return: 0 in case of success, else appropriate error value
+ */
+static int ti_iodelay_pinconf_set(struct ti_iodelay_device *iod,
+				  struct ti_iodelay_cfg *cfg)
+{
+	const struct ti_iodelay_reg_data *reg = iod->reg_data;
+	struct ti_iodelay_reg_values *ival = &iod->reg_init_conf_values;
+	struct device *dev = iod->dev;
+	u32 g_delay_coarse, g_delay_fine;
+	u32 a_delay_coarse, a_delay_fine;
+	u32 c_elements, f_elements;
+	u32 total_delay;
+	u32 reg_mask, reg_val, tmp_val;
+	int r;
+
+	/* NOTE: Truncation is expected in all division below */
+	g_delay_coarse = cfg->g_delay / 920;
+	g_delay_fine = ((cfg->g_delay % 920) * 10) / 60;
+
+	a_delay_coarse = cfg->a_delay / ival->cdpe;
+	a_delay_fine = ((cfg->a_delay % ival->cdpe) * 10) / ival->fdpe;
+
+	c_elements = g_delay_coarse + a_delay_coarse;
+	f_elements = (g_delay_fine + a_delay_fine) / 10;
+
+	if (f_elements > 22) {
+		total_delay = c_elements * ival->cdpe + f_elements * ival->fdpe;
+		c_elements = total_delay / ival->cdpe;
+		f_elements = (total_delay % ival->cdpe) / ival->fdpe;
+	}
+
+	reg_mask = reg->signature_mask;
+	reg_val = reg->signature_value << __ffs(reg->signature_mask);
+
+	reg_mask |= reg->binary_data_coarse_mask;
+	tmp_val = c_elements << __ffs(reg->binary_data_coarse_mask);
+	if (tmp_val & ~reg->binary_data_coarse_mask) {
+		dev_err(dev, "Masking overflow of coarse elements %08x\n",
+			tmp_val);
+		tmp_val &= reg->binary_data_coarse_mask;
+	}
+	reg_val |= tmp_val;
+
+	reg_mask |= reg->binary_data_fine_mask;
+	tmp_val = f_elements << __ffs(reg->binary_data_fine_mask);
+	if (tmp_val & ~reg->binary_data_fine_mask) {
+		dev_err(dev, "Masking overflow of fine elements %08x\n",
+			tmp_val);
+		tmp_val &= reg->binary_data_fine_mask;
+	}
+	reg_val |= tmp_val;
+
+	/*
+	 * NOTE: we leave the iodelay values unlocked - this is to work around
+	 * situations such as those found with mmc mode change.
+	 * However, this leaves open any unwarranted changes to padconf register
+	 * impacting iodelay configuration. Use with care!
+	 */
+	reg_mask |= reg->lock_mask;
+	reg_val |= reg->unlock_val << __ffs(reg->lock_mask);
+	r = regmap_update_bits(iod->regmap, cfg->offset, reg_mask, reg_val);
+
+	dev_info(dev, "Set reg 0x%x Delay(a: %d g: %d), Elements(C=%d F=%d)0x%x\n",
+		 cfg->offset, cfg->a_delay, cfg->g_delay, c_elements,
+		 f_elements, reg_val);
+
+	return r;
+}
+
+/**
+ * ti_iodelay_pinconf_init_dev() - Initialize IODelay device
+ * @iod: iodelay device
+ *
+ * Unlocks the iodelay region, computes the common parameters
+ *
+ * Return: 0 in case of success, else appropriate error value
+ */
+static int ti_iodelay_pinconf_init_dev(struct ti_iodelay_device *iod)
+{
+	const struct ti_iodelay_reg_data *reg = iod->reg_data;
+	struct device *dev = iod->dev;
+	struct ti_iodelay_reg_values *ival = &iod->reg_init_conf_values;
+	u32 val;
+	int r;
+
+	/* unlock the iodelay region */
+	r = regmap_update_bits(iod->regmap, reg->reg_global_lock_offset,
+			       reg->global_lock_mask, reg->global_unlock_val);
+	if (r)
+		return r;
+
+	/* Read up Recalibration sequence done by bootloader */
+	r = regmap_read(iod->regmap, reg->reg_refclk_offset, &val);
+	if (r)
+		return r;
+	ival->ref_clk_period = ti_iodelay_extract(val, reg->refclk_period_mask);
+	dev_dbg(dev, "refclk_period=0x%04x\n", ival->ref_clk_period);
+
+	r = regmap_read(iod->regmap, reg->reg_coarse_offset, &val);
+	if (r)
+		return r;
+	ival->coarse_ref_count =
+	    ti_iodelay_extract(val, reg->coarse_ref_count_mask);
+	ival->coarse_delay_count =
+	    ti_iodelay_extract(val, reg->coarse_delay_count_mask);
+	if (!ival->coarse_delay_count) {
+		dev_err(dev, "Invalid Coarse delay count (0) (reg=0x%08x)\n",
+			val);
+		return -EINVAL;
+	}
+	ival->cdpe = ti_iodelay_compute_dpe(ival->ref_clk_period,
+					    ival->coarse_ref_count,
+					    ival->coarse_delay_count, 88);
+	if (!ival->cdpe) {
+		dev_err(dev, "Invalid cdpe computed params = %d %d %d\n",
+			ival->ref_clk_period, ival->coarse_ref_count,
+			ival->coarse_delay_count);
+		return -EINVAL;
+	}
+	dev_dbg(iod->dev, "coarse: ref=0x%04x delay=0x%04x cdpe=0x%08x\n",
+		ival->coarse_ref_count, ival->coarse_delay_count, ival->cdpe);
+
+	r = regmap_read(iod->regmap, reg->reg_fine_offset, &val);
+	if (r)
+		return r;
+	ival->fine_ref_count =
+	    ti_iodelay_extract(val, reg->fine_ref_count_mask);
+	ival->fine_delay_count =
+	    ti_iodelay_extract(val, reg->fine_delay_count_mask);
+	if (!ival->fine_delay_count) {
+		dev_err(dev, "Invalid Fine delay count (0) (reg=0x%08x)\n",
+			val);
+		return -EINVAL;
+	}
+	ival->fdpe = ti_iodelay_compute_dpe(ival->ref_clk_period,
+					    ival->fine_ref_count,
+					    ival->fine_delay_count, 264);
+	if (!ival->fdpe) {
+		dev_err(dev, "Invalid fdpe(0) computed params = %d %d %d\n",
+			ival->ref_clk_period, ival->fine_ref_count,
+			ival->fine_delay_count);
+		return -EINVAL;
+	}
+	dev_dbg(iod->dev, "fine: ref=0x%04x delay=0x%04x fdpe=0x%08x\n",
+		ival->fine_ref_count, ival->fine_delay_count, ival->fdpe);
+
+	return 0;
+}
+
+/**
+ * ti_iodelay_pinconf_deinit_dev() - deinit the iodelay device
+ * @iod:	IODelay device
+ *
+ * Deinitialize the IODelay device (basically just lock the region back up.
+ */
+static void ti_iodelay_pinconf_deinit_dev(struct ti_iodelay_device *iod)
+{
+	const struct ti_iodelay_reg_data *reg = iod->reg_data;
+
+	/* lock the iodelay region back again */
+	regmap_update_bits(iod->regmap, reg->reg_global_lock_offset,
+			   reg->global_lock_mask, reg->global_lock_val);
+}
+
+/**
+ * ti_iodelay_get_pingroup() - Find the group mapped by a group selector
+ * @iod: iodelay device
+ * @selector: Group Selector
+ *
+ * Return: Corresponding group representing group selector
+ */
+static struct ti_iodelay_pingroup *
+ti_iodelay_get_pingroup(struct ti_iodelay_device *iod, unsigned int selector)
+{
+	struct group_desc *g;
+
+	g = pinctrl_generic_get_group(iod->pctl, selector);
+	if (!g) {
+		dev_err(iod->dev, "%s could not find pingroup %i\n", __func__,
+			selector);
+
+		return NULL;
+	}
+
+	return g->data;
+}
+
+/**
+ * ti_iodelay_offset_to_pin() - get a pin index based on the register offset
+ * @iod: iodelay driver instance
+ * @offset: register offset from the base
+ */
+static int ti_iodelay_offset_to_pin(struct ti_iodelay_device *iod,
+				    unsigned int offset)
+{
+	const struct ti_iodelay_reg_data *r = iod->reg_data;
+	unsigned int index;
+
+	if (offset > r->regmap_config->max_register) {
+		dev_err(iod->dev, "mux offset out of range: 0x%x (0x%x)\n",
+			offset, r->regmap_config->max_register);
+		return -EINVAL;
+	}
+
+	index = (offset - r->reg_start_offset) / r->regmap_config->reg_stride;
+	index /= r->reg_nr_per_pin;
+
+	return index;
+}
+
+/**
+ *
+ * @pctldev: Pin controller driver
+ * @np: Device node
+ * @pinctrl_spec: Parsed arguments from device tree
+ * @pins: Array of pins in the pin group
+ * @pin_index: Pin index in the pin array
+ * @data: Pin controller driver specific data
+ *
+ */
+static int ti_iodelay_node_iterator(struct pinctrl_dev *pctldev,
+				    struct device_node *np,
+				    const struct of_phandle_args *pinctrl_spec,
+				    int *pins, int pin_index, void *data)
+{
+	struct ti_iodelay_device *iod;
+	struct ti_iodelay_cfg *cfg = data;
+	const struct ti_iodelay_reg_data *r;
+	struct pinctrl_pin_desc *pd;
+	int pin;
+
+	iod = pinctrl_dev_get_drvdata(pctldev);
+	if (!iod)
+		return -EINVAL;
+
+	r = iod->reg_data;
+
+	if (pinctrl_spec->args_count < r->reg_nr_per_pin) {
+		dev_err(iod->dev, "invalid args_count for spec: %i\n",
+			pinctrl_spec->args_count);
+
+		return -EINVAL;
+	}
+
+	/* Index plus two value cells */
+	cfg[pin_index].offset = pinctrl_spec->args[0];
+	cfg[pin_index].a_delay = pinctrl_spec->args[1] & 0xffff;
+	cfg[pin_index].g_delay = pinctrl_spec->args[2] & 0xffff;
+
+	pin = ti_iodelay_offset_to_pin(iod, cfg[pin_index].offset);
+	if (pin < 0) {
+		dev_err(iod->dev, "could not add functions for %s %ux\n",
+			np->name, cfg[pin_index].offset);
+		return -ENODEV;
+	}
+	pins[pin_index] = pin;
+
+	pd = &iod->pa[pin];
+	pd->drv_data = &cfg[pin_index];
+
+	dev_dbg(iod->dev, "%s offset=%x a_delay = %d g_delay = %d\n",
+		np->name, cfg[pin_index].offset, cfg[pin_index].a_delay,
+		cfg[pin_index].g_delay);
+
+	return 0;
+}
+
+/**
+ * ti_iodelay_dt_node_to_map() - Map a device tree node to appropriate group
+ * @pctldev: pinctrl device representing IODelay device
+ * @np: Node Pointer (device tree)
+ * @map: Pinctrl Map returned back to pinctrl framework
+ * @num_maps: Number of maps (1)
+ *
+ * Maps the device tree description into a group of configuration parameters
+ * for iodelay block entry.
+ *
+ * Return: 0 in case of success, else appropriate error value
+ */
+static int ti_iodelay_dt_node_to_map(struct pinctrl_dev *pctldev,
+				     struct device_node *np,
+				     struct pinctrl_map **map,
+				     unsigned int *num_maps)
+{
+	struct ti_iodelay_device *iod;
+	struct ti_iodelay_cfg *cfg;
+	struct ti_iodelay_pingroup *g;
+	const char *name = "pinctrl-pin-array";
+	int rows, *pins, error = -EINVAL, i;
+
+	iod = pinctrl_dev_get_drvdata(pctldev);
+	if (!iod)
+		return -EINVAL;
+
+	rows = pinctrl_count_index_with_args(np, name);
+	if (rows == -EINVAL)
+		return rows;
+
+	*map = devm_kzalloc(iod->dev, sizeof(**map), GFP_KERNEL);
+	if (!*map)
+		return -ENOMEM;
+	*num_maps = 0;
+
+	g = devm_kzalloc(iod->dev, sizeof(*g), GFP_KERNEL);
+	if (!g) {
+		error = -ENOMEM;
+		goto free_map;
+	}
+
+	pins = devm_kzalloc(iod->dev, sizeof(*pins) * rows, GFP_KERNEL);
+	if (!pins)
+		goto free_group;
+
+	cfg = devm_kzalloc(iod->dev, sizeof(*cfg) * rows, GFP_KERNEL);
+	if (!cfg) {
+		error = -ENOMEM;
+		goto free_pins;
+	}
+
+	for (i = 0; i < rows; i++) {
+		struct of_phandle_args pinctrl_spec;
+
+		error = pinctrl_parse_index_with_args(np, name, i,
+						      &pinctrl_spec);
+		if (error)
+			goto free_data;
+
+		error = ti_iodelay_node_iterator(pctldev, np, &pinctrl_spec,
+						 pins, i, cfg);
+		if (error)
+			goto free_data;
+	}
+
+	g->cfg = cfg;
+	g->ncfg = i;
+	g->config = PIN_CONFIG_END;
+
+	error = pinctrl_generic_add_group(iod->pctl, np->name, pins, i, g);
+	if (error < 0)
+		goto free_data;
+
+	(*map)->type = PIN_MAP_TYPE_CONFIGS_GROUP;
+	(*map)->data.configs.group_or_pin = np->name;
+	(*map)->data.configs.configs = &g->config;
+	(*map)->data.configs.num_configs = 1;
+	*num_maps = 1;
+
+	return 0;
+
+free_data:
+	devm_kfree(iod->dev, cfg);
+free_pins:
+	devm_kfree(iod->dev, pins);
+free_group:
+	devm_kfree(iod->dev, g);
+free_map:
+	devm_kfree(iod->dev, *map);
+
+	return error;
+}
+
+/**
+ * ti_iodelay_pinconf_group_get() - Get the group configuration
+ * @pctldev: pinctrl device representing IODelay device
+ * @selector: Group selector
+ * @config: Configuration returned
+ *
+ * Return: The configuration if the group is valid, else returns -EINVAL
+ */
+static int ti_iodelay_pinconf_group_get(struct pinctrl_dev *pctldev,
+					unsigned int selector,
+					unsigned long *config)
+{
+	struct ti_iodelay_device *iod;
+	struct device *dev;
+	struct ti_iodelay_pingroup *group;
+
+	iod = pinctrl_dev_get_drvdata(pctldev);
+	dev = iod->dev;
+	group = ti_iodelay_get_pingroup(iod, selector);
+
+	if (!group)
+		return -EINVAL;
+
+	*config = group->config;
+	return 0;
+}
+
+/**
+ * ti_iodelay_pinconf_group_set() - Configure the groups of pins
+ * @pctldev: pinctrl device representing IODelay device
+ * @selector: Group selector
+ * @configs: Configurations
+ * @num_configs: Number of configurations
+ *
+ * Return: 0 if all went fine, else appropriate error value.
+ */
+static int ti_iodelay_pinconf_group_set(struct pinctrl_dev *pctldev,
+					unsigned int selector,
+					unsigned long *configs,
+					unsigned int num_configs)
+{
+	struct ti_iodelay_device *iod;
+	struct device *dev;
+	struct ti_iodelay_pingroup *group;
+	int i;
+
+	iod = pinctrl_dev_get_drvdata(pctldev);
+	dev = iod->dev;
+	group = ti_iodelay_get_pingroup(iod, selector);
+
+	if (num_configs != 1) {
+		dev_err(dev, "Unsupported number of configurations %d\n",
+			num_configs);
+		return -EINVAL;
+	}
+
+	if (*configs != PIN_CONFIG_END) {
+		dev_err(dev, "Unsupported configuration\n");
+		return -EINVAL;
+	}
+
+	for (i = 0; i < group->ncfg; i++) {
+		if (ti_iodelay_pinconf_set(iod, &group->cfg[i]))
+			return -ENOTSUPP;
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_DEBUG_FS
+/**
+ * ti_iodelay_pin_to_offset() - get pin register offset based on the pin index
+ * @iod: iodelay driver instance
+ * @selector: Pin index
+ */
+static unsigned int ti_iodelay_pin_to_offset(struct ti_iodelay_device *iod,
+					     unsigned int selector)
+{
+	const struct ti_iodelay_reg_data *r = iod->reg_data;
+	unsigned int offset;
+
+	offset = selector * r->regmap_config->reg_stride;
+	offset *= r->reg_nr_per_pin;
+	offset += r->reg_start_offset;
+
+	return offset;
+}
+
+static void ti_iodelay_pin_dbg_show(struct pinctrl_dev *pctldev,
+				    struct seq_file *s,
+				    unsigned int pin)
+{
+	struct ti_iodelay_device *iod;
+	struct pinctrl_pin_desc *pd;
+	struct ti_iodelay_cfg *cfg;
+	const struct ti_iodelay_reg_data *r;
+	unsigned long offset;
+	u32 in, oen, out;
+
+	iod = pinctrl_dev_get_drvdata(pctldev);
+	r = iod->reg_data;
+
+	offset = ti_iodelay_pin_to_offset(iod, pin);
+	if (pin < 0) {
+		dev_err(iod->dev, "invalid pin offset for pin%i\n", pin);
+
+		return;
+	}
+
+	pd = &iod->pa[pin];
+	cfg = pd->drv_data;
+
+	regmap_read(iod->regmap, offset, &in);
+	regmap_read(iod->regmap, offset + r->regmap_config->reg_stride, &oen);
+	regmap_read(iod->regmap, offset + r->regmap_config->reg_stride * 2,
+		    &out);
+
+	seq_printf(s, "%lx a: %i g: %i (%08x %08x %08x) %s ",
+		   iod->phys_base + offset,
+		   cfg ? cfg->a_delay : -1,
+		   cfg ? cfg->g_delay : -1,
+		   in, oen, out, DRIVER_NAME);
+}
+
+/**
+ * ti_iodelay_pinconf_group_dbg_show() - show the group information
+ * @pctldev: Show the group information
+ * @s: Sequence file
+ * @selector: Group selector
+ *
+ * Provide the configuration information of the selected group
+ */
+static void ti_iodelay_pinconf_group_dbg_show(struct pinctrl_dev *pctldev,
+					      struct seq_file *s,
+					      unsigned int selector)
+{
+	struct ti_iodelay_device *iod;
+	struct device *dev;
+	struct ti_iodelay_pingroup *group;
+	int i;
+
+	iod = pinctrl_dev_get_drvdata(pctldev);
+	dev = iod->dev;
+	group = ti_iodelay_get_pingroup(iod, selector);
+	if (!group)
+		return;
+
+	for (i = 0; i < group->ncfg; i++) {
+		struct ti_iodelay_cfg *cfg;
+		u32 reg = 0;
+
+		cfg = &group->cfg[i];
+		regmap_read(iod->regmap, cfg->offset, &reg),
+			seq_printf(s, "\n\t0x%08x = 0x%08x (%3d, %3d)",
+				   cfg->offset, reg, cfg->a_delay,
+				   cfg->g_delay);
+	}
+}
+#endif
+
+static struct pinctrl_ops ti_iodelay_pinctrl_ops = {
+	.get_groups_count = pinctrl_generic_get_group_count,
+	.get_group_name = pinctrl_generic_get_group_name,
+	.get_group_pins = pinctrl_generic_get_group_pins,
+#ifdef CONFIG_DEBUG_FS
+	.pin_dbg_show = ti_iodelay_pin_dbg_show,
+#endif
+	.dt_node_to_map = ti_iodelay_dt_node_to_map,
+};
+
+static struct pinconf_ops ti_iodelay_pinctrl_pinconf_ops = {
+	.pin_config_group_get = ti_iodelay_pinconf_group_get,
+	.pin_config_group_set = ti_iodelay_pinconf_group_set,
+#ifdef CONFIG_DEBUG_FS
+	.pin_config_group_dbg_show = ti_iodelay_pinconf_group_dbg_show,
+#endif
+};
+
+/**
+ * ti_iodelay_alloc_pins() - Allocate structures needed for pins for iodelay
+ * @dev: Device pointer
+ * @iod: iodelay device
+ * @base_phy: Base Physical Address
+ *
+ * Return: 0 if all went fine, else appropriate error value.
+ */
+static int ti_iodelay_alloc_pins(struct device *dev,
+				 struct ti_iodelay_device *iod, u32 base_phy)
+{
+	const struct ti_iodelay_reg_data *r = iod->reg_data;
+	struct pinctrl_pin_desc *pin;
+	u32 phy_reg;
+	int nr_pins, i;
+
+	nr_pins = ti_iodelay_offset_to_pin(iod, r->regmap_config->max_register);
+	dev_dbg(dev, "Allocating %i pins\n", nr_pins);
+
+	iod->pa = devm_kzalloc(dev, sizeof(*iod->pa) * nr_pins, GFP_KERNEL);
+	if (!iod->pa)
+		return -ENOMEM;
+
+	iod->desc.pins = iod->pa;
+	iod->desc.npins = nr_pins;
+
+	phy_reg = r->reg_start_offset + base_phy;
+
+	for (i = 0; i < nr_pins; i++, phy_reg += 4) {
+		pin = &iod->pa[i];
+		pin->number = i;
+	}
+
+	return 0;
+}
+
+static struct regmap_config dra7_iodelay_regmap_config = {
+	.reg_bits = 32,
+	.reg_stride = 4,
+	.val_bits = 32,
+	.max_register = 0xd1c,
+};
+
+static struct ti_iodelay_reg_data dra7_iodelay_data = {
+	.signature_mask = 0x0003f000,
+	.signature_value = 0x29,
+	.lock_mask = 0x00000400,
+	.lock_val = 1,
+	.unlock_val = 0,
+	.binary_data_coarse_mask = 0x000003e0,
+	.binary_data_fine_mask = 0x0000001f,
+
+	.reg_refclk_offset = 0x14,
+	.refclk_period_mask = 0xffff,
+
+	.reg_coarse_offset = 0x18,
+	.coarse_delay_count_mask = 0xffff0000,
+	.coarse_ref_count_mask = 0x0000ffff,
+
+	.reg_fine_offset = 0x1C,
+	.fine_delay_count_mask = 0xffff0000,
+	.fine_ref_count_mask = 0x0000ffff,
+
+	.reg_global_lock_offset = 0x2c,
+	.global_lock_mask = 0x0000ffff,
+	.global_unlock_val = 0x0000aaaa,
+	.global_lock_val = 0x0000aaab,
+
+	.reg_start_offset = 0x30,
+	.reg_nr_per_pin = 3,
+	.regmap_config = &dra7_iodelay_regmap_config,
+};
+
+static const struct of_device_id ti_iodelay_of_match[] = {
+	{.compatible = "ti,dra7-iodelay", .data = &dra7_iodelay_data},
+	{ /* Hopefully no more.. */ },
+};
+MODULE_DEVICE_TABLE(of, ti_iodelay_of_match);
+
+/**
+ * ti_iodelay_probe() - Standard probe
+ * @pdev: platform device
+ *
+ * Return: 0 if all went fine, else appropriate error value.
+ */
+static int ti_iodelay_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = of_node_get(dev->of_node);
+	const struct of_device_id *match;
+	struct resource *res;
+	struct ti_iodelay_device *iod;
+	int ret = 0;
+
+	if (!np) {
+		ret = -EINVAL;
+		dev_err(dev, "No OF node\n");
+		goto exit_out;
+	}
+
+	match = of_match_device(ti_iodelay_of_match, dev);
+	if (!match) {
+		ret = -EINVAL;
+		dev_err(dev, "No DATA match\n");
+		goto exit_out;
+	}
+
+	iod = devm_kzalloc(dev, sizeof(*iod), GFP_KERNEL);
+	if (!iod) {
+		ret = -ENOMEM;
+		goto exit_out;
+	}
+	iod->dev = dev;
+	iod->reg_data = match->data;
+
+	/* So far We can assume there is only 1 bank of registers */
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(dev, "Missing MEM resource\n");
+		ret = -ENODEV;
+		goto exit_out;
+	}
+
+	iod->phys_base = res->start;
+	iod->reg_base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(iod->reg_base)) {
+		ret = PTR_ERR(iod->reg_base);
+		goto exit_out;
+	}
+
+	iod->regmap = devm_regmap_init_mmio(dev, iod->reg_base,
+					    iod->reg_data->regmap_config);
+	if (IS_ERR(iod->regmap)) {
+		dev_err(dev, "Regmap MMIO init failed.\n");
+		ret = PTR_ERR(iod->regmap);
+		goto exit_out;
+	}
+
+	if (ti_iodelay_pinconf_init_dev(iod))
+		goto exit_out;
+
+	ret = ti_iodelay_alloc_pins(dev, iod, res->start);
+	if (ret)
+		goto exit_out;
+
+	iod->desc.pctlops = &ti_iodelay_pinctrl_ops;
+	/* no pinmux ops - we are pinconf */
+	iod->desc.confops = &ti_iodelay_pinctrl_pinconf_ops;
+	iod->desc.name = dev_name(dev);
+	iod->desc.owner = THIS_MODULE;
+
+	iod->pctl = pinctrl_register(&iod->desc, dev, iod);
+	if (!iod->pctl) {
+		dev_err(dev, "Failed to register pinctrl\n");
+		ret = -ENODEV;
+		goto exit_out;
+	}
+
+	platform_set_drvdata(pdev, iod);
+
+exit_out:
+	of_node_put(np);
+	return ret;
+}
+
+/**
+ * ti_iodelay_remove() - standard remove
+ * @pdev: platform device
+ *
+ * Return: 0 if all went fine, else appropriate error value.
+ */
+static int ti_iodelay_remove(struct platform_device *pdev)
+{
+	struct ti_iodelay_device *iod = platform_get_drvdata(pdev);
+
+	if (!iod)
+		return 0;
+
+	if (iod->pctl)
+		pinctrl_unregister(iod->pctl);
+
+	ti_iodelay_pinconf_deinit_dev(iod);
+
+	/* Expect other allocations to be freed by devm */
+
+	return 0;
+}
+
+static struct platform_driver ti_iodelay_driver = {
+	.probe = ti_iodelay_probe,
+	.remove = ti_iodelay_remove,
+	.driver = {
+		   .owner = THIS_MODULE,
+		   .name = DRIVER_NAME,
+		   .of_match_table = ti_iodelay_of_match,
+	},
+};
+module_platform_driver(ti_iodelay_driver);
+
+MODULE_AUTHOR("Texas Instruments, Inc.");
+MODULE_DESCRIPTION("Pinconf driver for TI's IO Delay module");
+MODULE_LICENSE("GPL v2");
-- 
2.11.0
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Re: [PATCH 2/2] pinctrl: Introduce TI IOdelay configuration driver

[Rob Herring]

On Mon, Jan 02, 2017 at 02:12:28PM -0800, Tony Lindgren wrote:
> * Tony Lindgren <tony@atomide.com> [161230 10:38]:
> > +static struct pinctrl_ops ti_iodelay_pinctrl_ops = {
> > +	.get_groups_count = pinctrl_generic_get_group_count,
> > +	.get_group_name = pinctrl_generic_get_group_name,
> > +	.get_group_pins = pinctrl_generic_get_group_pins,
> > +	.pin_dbg_show = ti_iodelay_pin_dbg_show,
> > +	.dt_node_to_map = ti_iodelay_dt_node_to_map,
> > +};
> > +
> > +static struct pinconf_ops ti_iodelay_pinctrl_pinconf_ops = {
> > +	.pin_config_group_get = ti_iodelay_pinconf_group_get,
> > +	.pin_config_group_set = ti_iodelay_pinconf_group_set,
> > +#ifdef CONFIG_DEBUG_FS
> > +	.pin_config_group_dbg_show = ti_iodelay_pinconf_group_dbg_show,
> > +#endif
> 
> I noticed that .pin_dbg_show above needs ifdef CONFIG_DEBUGFS.
> Updated patch below.
> 
> Regards,
> 
> Tony
> 
> 8< --------------------
> From tony Mon Sep 17 00:00:00 2001
> From: Nishanth Menon <nm@ti.com>
> Date: Tue, 27 Dec 2016 08:03:43 -0800
> Subject: [PATCH] pinctrl: Introduce TI IOdelay configuration driver
> 
> SoC family such as DRA7 family of processors have, in addition
> to the regular muxing of pins (as done by pinctrl-single), a separate
> hardware module called IODelay which is also expected to be configured.
> The "IODelay" module has it's own register space that is independent
> of the control module and the padconf register area.
> 
> With recent changes to the pinctrl framework, we can now support
> this hardware with a reasonably minimal driver by using #pinctrl-cells,
> GENERIC_PINCTRL_GROUPS and GENERIC_PINMUX_FUNCTIONS.
> 
> It is advocated strongly in TI's official documentation considering
> the existing design of the DRA7 family of processors during mux or
> IODelay reconfiguration, there is a potential for a significant glitch
> which may cause functional impairment to certain hardware. It is
> hence recommended to do as little of muxing as absolutely necessary
> without I/O isolation (which can only be done in initial stages of
> bootloader).
> 
> NOTE: with the system wide I/O isolation scheme present in DRA7 SoC
> family, it is not reasonable to do stop all I/O operations for every
> such pad configuration scheme. So, we will let it glitch when used in
> this mode.
> 
> Even with the above limitation, certain functionality such as MMC has
> mandatory need for IODelay reconfiguration requirements, depending on
> speed of transfer. In these cases, with careful examination of usecase
> involved, the expected glitch can be controlled such that it does not
> impact functionality.
> 
> In short, IODelay module support as a padconf driver being introduced
> here is not expected to do SoC wide I/O Isolation and is meant for
> a limited subset of IODelay configuration requirements that need to
> be dynamic and whose glitchy behavior will not cause functionality
> failure for that interface.
> 
> IMPORTANT NOTE: we take the approach of keeping LOCK_BITs cleared
> to 0x0 at all times, even when configuring Manual IO Timing Modes.
> This is done by eliminating the LOCK_BIT=1 setting from Step
> of the Manual IO timing Mode configuration procedure. This option
> leaves the CFG_* registers unprotected from unintended writes to the
> CTRL_CORE_PAD_* registers while Manual IO Timing Modes are configured.
> 
> This approach is taken to allow for a generic driver to exist in kernel
> world that has to be used carefully in required usecases.
> 
> Signed-off-by: Nishanth Menon <nm@ti.com>
> Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
> [tony@atomide.com: updated to use generic pinctrl functions, added
>  binding documentation, updated comments]
> Signed-off-by: Tony Lindgren <tony@atomide.com>
> ---
>  .../devicetree/bindings/pinctrl/ti,iodelay.txt     |  47 +

Acked-by: Rob Herring <robh@kernel.org>

>  drivers/pinctrl/Kconfig                            |   1 +
>  drivers/pinctrl/Makefile                           |   1 +
>  drivers/pinctrl/ti/Kconfig                         |  10 +
>  drivers/pinctrl/ti/Makefile                        |   1 +
>  drivers/pinctrl/ti/pinctrl-ti-iodelay.c            | 947 +++++++++++++++++++++
>  6 files changed, 1007 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/pinctrl/ti,iodelay.txt
>  create mode 100644 drivers/pinctrl/ti/Kconfig
>  create mode 100644 drivers/pinctrl/ti/Makefile
>  create mode 100644 drivers/pinctrl/ti/pinctrl-ti-iodelay.c

Re: [PATCH 2/2] pinctrl: Introduce TI IOdelay configuration driver

[Nishanth Menon]

On 01/02/2017 04:12 PM, Tony Lindgren wrote:
[...]
Minor one:
> + * Copyright (C) 2015 Texas Instruments, Inc.
Could you make this:
  Copyright (C) 2015-2017 Texas Instruments Incorporated - 
http://www.ti.com/


-- 
Regards,
Nishanth Menon

Re: [PATCH 2/2] pinctrl: Introduce TI IOdelay configuration driver

[Tony Lindgren]

* Nishanth Menon <nm-l0cyMroinI0@public.gmane.org> [170104 07:39]:
> On 01/02/2017 04:12 PM, Tony Lindgren wrote:
> [...]
> Minor one:
> > + * Copyright (C) 2015 Texas Instruments, Inc.
> Could you make this:
>  Copyright (C) 2015-2017 Texas Instruments Incorporated - http://www.ti.com/

Sure, it's your patch :) Will repost.

Regards,

Tony
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Re: [PATCH 2/2] pinctrl: Introduce TI IOdelay configuration driver

[Nishanth Menon]

On 01/04/2017 10:05 AM, Tony Lindgren wrote:
> * Nishanth Menon <nm-l0cyMroinI0@public.gmane.org> [170104 07:39]:
>> On 01/02/2017 04:12 PM, Tony Lindgren wrote:
>> [...]
>> Minor one:
>>> + * Copyright (C) 2015 Texas Instruments, Inc.
>> Could you make this:
>>  Copyright (C) 2015-2017 Texas Instruments Incorporated - http://www.ti.com/
>
> Sure, it's your patch :) Will repost.
Thanks.

I just finished testing it as well and well it still does the job it 
used to do. thanks for taking this forward.

I did get a few kernel-doc warnings, which i need to look closer at. 
will comment back today if I see something of use for us to fix up.


-- 
Regards,
Nishanth Menon
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Re: [PATCH 2/2] pinctrl: Introduce TI IOdelay configuration driver

[Nishanth Menon]

On 01/02/2017 04:12 PM, Tony Lindgren wrote:
[...]

I got the following warnings with kernel-doc:
> $ ./scripts/kernel-doc drivers/pinctrl/ti/pinctrl-ti-iodelay.c>/dev/null
> drivers/pinctrl/ti/pinctrl-ti-iodelay.c:132: warning: Excess struct/union/enum/typedef member 'name' description in 'ti_iodelay_pingroup'
> drivers/pinctrl/ti/pinctrl-ti-iodelay.c:132: warning: Excess struct/union/enum/typedef member 'map' description in 'ti_iodelay_pingroup'
> drivers/pinctrl/ti/pinctrl-ti-iodelay.c:159: warning: Excess struct/union/enum/typedef member 'names' description in 'ti_iodelay_device'
> drivers/pinctrl/ti/pinctrl-ti-iodelay.c:211: warning: No description found for parameter 'cfg'
> drivers/pinctrl/ti/pinctrl-ti-iodelay.c:211: warning: Excess function parameter 'val' description in 'ti_iodelay_pinconf_set'
> drivers/pinctrl/ti/pinctrl-ti-iodelay.c:418: warning: Cannot understand  *
>  on line 418 - I thought it was a doc line

Marking them below

> diff --git a/drivers/pinctrl/ti/pinctrl-ti-iodelay.c b/drivers/pinctrl/ti/pinctrl-ti-iodelay.c
> new file mode 100644
> --- /dev/null
> +++ b/drivers/pinctrl/ti/pinctrl-ti-iodelay.c
[...]

> +/**
> + * struct ti_iodelay_pingroup - Structure that describes one group
> + * @name: Name of the group

          ^^--> we should drop this

> + * @map: pinctrl map allocated for the group

          ^^--> we should drop this

> + * @cfg: configuration array for the pin (from dt)
> + * @ncfg: number of configuration values allocated
> + * @config: pinconf "Config" - currently a dummy value
> + */
> +struct ti_iodelay_pingroup {
> +	struct ti_iodelay_cfg *cfg;
> +	int ncfg;
> +	unsigned long config;
> +};
> +
> +/**
> + * struct ti_iodelay_device - Represents information for a iodelay instance
> + * @dev: Device pointer
> + * @phys_base: Physical address base of the iodelay device
> + * @reg_base: Virtual address base of the iodelay device
> + * @regmap: Regmap for this iodelay instance
> + * @pctl: Pinctrl device
> + * @desc: pinctrl descriptor for pctl
> + * @pa: pinctrl pin wise description
> + * @names: names of the pins

          ^^--> we should drop this

> + * @reg_data: Register definition data for the IODelay instance
> + * @reg_init_conf_values: Initial configuration values.
> + */
> +struct ti_iodelay_device {
> +	struct device *dev;
> +	unsigned long phys_base;
> +	void __iomem *reg_base;
> +	struct regmap *regmap;
> +
> +	struct pinctrl_dev *pctl;
> +	struct pinctrl_desc desc;
> +	struct pinctrl_pin_desc *pa;
> +
> +	const struct ti_iodelay_reg_data *reg_data;
> +	struct ti_iodelay_reg_values reg_init_conf_values;
> +};
> +

[...]

> +/**
> + * ti_iodelay_pinconf_set() - Configure the pin configuration
> + * @iod: iodelay device
> + * @val: Configuration value
        ^^ --> should be cfg ?
> + *
> + * Update the configuration register as per TRM and lockup once done.
> + * *IMPORTANT NOTE* SoC TRM does recommend doing iodelay programmation only
> + * while in Isolation. But, then, isolation also implies that every pin
> + * on the SoC (including DDR) will be isolated out. The only benefit being
> + * a glitchless configuration, However, the intent of this driver is purely
> + * to support a "glitchy" configuration where applicable.
> + *
> + * Return: 0 in case of success, else appropriate error value
> + */
> +static int ti_iodelay_pinconf_set(struct ti_iodelay_device *iod,
> +				  struct ti_iodelay_cfg *cfg)
[...]

> +
> +/**
> + *
Could you make this:
  * ti_iodelay_node_iterator() - Iterate iodelay node

> + * @pctldev: Pin controller driver
> + * @np: Device node
> + * @pinctrl_spec: Parsed arguments from device tree
> + * @pins: Array of pins in the pin group
> + * @pin_index: Pin index in the pin array
> + * @data: Pin controller driver specific data
> + *
> + */
> +static int ti_iodelay_node_iterator(struct pinctrl_dev *pctldev,
> +				    struct device_node *np,
> +				    const struct of_phandle_args *pinctrl_spec,
> +				    int *pins, int pin_index, void *data)

[...]

Otherwise, the patch looks fine. Thanks for doing this.

-- 
Regards,
Nishanth Menon
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Re: [PATCH 2/2] pinctrl: Introduce TI IOdelay configuration driver

[Tony Lindgren]

* Nishanth Menon <nm@ti.com> [170104 09:58]:
> On 01/02/2017 04:12 PM, Tony Lindgren wrote:
> [...]
> 
> I got the following warnings with kernel-doc:
> > $ ./scripts/kernel-doc drivers/pinctrl/ti/pinctrl-ti-iodelay.c>/dev/null
> > drivers/pinctrl/ti/pinctrl-ti-iodelay.c:132: warning: Excess struct/union/enum/typedef member 'name' description in 'ti_iodelay_pingroup'
> > drivers/pinctrl/ti/pinctrl-ti-iodelay.c:132: warning: Excess struct/union/enum/typedef member 'map' description in 'ti_iodelay_pingroup'
> > drivers/pinctrl/ti/pinctrl-ti-iodelay.c:159: warning: Excess struct/union/enum/typedef member 'names' description in 'ti_iodelay_device'
> > drivers/pinctrl/ti/pinctrl-ti-iodelay.c:211: warning: No description found for parameter 'cfg'
> > drivers/pinctrl/ti/pinctrl-ti-iodelay.c:211: warning: Excess function parameter 'val' description in 'ti_iodelay_pinconf_set'
> > drivers/pinctrl/ti/pinctrl-ti-iodelay.c:418: warning: Cannot understand  *
> >  on line 418 - I thought it was a doc line
> 
> Marking them below

OK thanks will repost v3 shortly.

Regards,

Tony

[PATCHv3 0/2] Add TI iodelay driver using #pinctrl-cells

[Tony Lindgren]

Hi,

Here's a v3 respin of Nishanth's iodelay driver that I've updated to
use #pinctrl-cells and generic pinctrl group and function code.

Gary, note that this one has an iterator function that you may
be able to use too, and hopefully we can simplify things further
eventually by introducing a generic iterator.

Regards,

Tony

Changes since v1
- Fix compile error if CONFIG_DEBUG_FS is not set

Changes since v2
- Update with Nishanth's kerneldoc comments
- Added Rob's ack

Nishanth Menon (1):
  pinctrl: Introduce TI IOdelay configuration driver

Tony Lindgren (1):
  pinctrl: core: Make dt_free_map optional

 .../devicetree/bindings/pinctrl/ti,iodelay.txt     |  47 +
 drivers/pinctrl/Kconfig                            |   1 +
 drivers/pinctrl/Makefile                           |   1 +
 drivers/pinctrl/core.c                             |   3 -
 drivers/pinctrl/devicetree.c                       |   3 +-
 drivers/pinctrl/ti/Kconfig                         |  10 +
 drivers/pinctrl/ti/Makefile                        |   1 +
 drivers/pinctrl/ti/pinctrl-ti-iodelay.c            | 944 +++++++++++++++++++++
 8 files changed, 1006 insertions(+), 4 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/pinctrl/ti,iodelay.txt
 create mode 100644 drivers/pinctrl/ti/Kconfig
 create mode 100644 drivers/pinctrl/ti/Makefile
 create mode 100644 drivers/pinctrl/ti/pinctrl-ti-iodelay.c

-- 
2.11.0

[PATCH 2/2] pinctrl: Introduce TI IOdelay configuration driver

[Tony Lindgren]

From: Nishanth Menon <nm-l0cyMroinI0@public.gmane.org>

SoC family such as DRA7 family of processors have, in addition
to the regular muxing of pins (as done by pinctrl-single), a separate
hardware module called IODelay which is also expected to be configured.
The "IODelay" module has it's own register space that is independent
of the control module and the padconf register area.

With recent changes to the pinctrl framework, we can now support
this hardware with a reasonably minimal driver by using #pinctrl-cells,
GENERIC_PINCTRL_GROUPS and GENERIC_PINMUX_FUNCTIONS.

It is advocated strongly in TI's official documentation considering
the existing design of the DRA7 family of processors during mux or
IODelay reconfiguration, there is a potential for a significant glitch
which may cause functional impairment to certain hardware. It is
hence recommended to do as little of muxing as absolutely necessary
without I/O isolation (which can only be done in initial stages of
bootloader).

NOTE: with the system wide I/O isolation scheme present in DRA7 SoC
family, it is not reasonable to do stop all I/O operations for every
such pad configuration scheme. So, we will let it glitch when used in
this mode.

Even with the above limitation, certain functionality such as MMC has
mandatory need for IODelay reconfiguration requirements, depending on
speed of transfer. In these cases, with careful examination of usecase
involved, the expected glitch can be controlled such that it does not
impact functionality.

In short, IODelay module support as a padconf driver being introduced
here is not expected to do SoC wide I/O Isolation and is meant for
a limited subset of IODelay configuration requirements that need to
be dynamic and whose glitchy behavior will not cause functionality
failure for that interface.

IMPORTANT NOTE: we take the approach of keeping LOCK_BITs cleared
to 0x0 at all times, even when configuring Manual IO Timing Modes.
This is done by eliminating the LOCK_BIT=1 setting from Step
of the Manual IO timing Mode configuration procedure. This option
leaves the CFG_* registers unprotected from unintended writes to the
CTRL_CORE_PAD_* registers while Manual IO Timing Modes are configured.

This approach is taken to allow for a generic driver to exist in kernel
world that has to be used carefully in required usecases.

Signed-off-by: Nishanth Menon <nm-l0cyMroinI0@public.gmane.org>
Signed-off-by: Lokesh Vutla <lokeshvutla-l0cyMroinI0@public.gmane.org>
[tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org: updated to use generic pinctrl functions, added
 binding documentation, updated comments]
Acked-by: Rob Herring <robh-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Signed-off-by: Tony Lindgren <tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org>
---
 .../devicetree/bindings/pinctrl/ti,iodelay.txt     |  47 +
 drivers/pinctrl/Kconfig                            |   1 +
 drivers/pinctrl/Makefile                           |   1 +
 drivers/pinctrl/ti/Kconfig                         |  10 +
 drivers/pinctrl/ti/Makefile                        |   1 +
 drivers/pinctrl/ti/pinctrl-ti-iodelay.c            | 944 +++++++++++++++++++++
 6 files changed, 1004 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pinctrl/ti,iodelay.txt
 create mode 100644 drivers/pinctrl/ti/Kconfig
 create mode 100644 drivers/pinctrl/ti/Makefile
 create mode 100644 drivers/pinctrl/ti/pinctrl-ti-iodelay.c

diff --git a/Documentation/devicetree/bindings/pinctrl/ti,iodelay.txt b/Documentation/devicetree/bindings/pinctrl/ti,iodelay.txt
new file mode 100644
--- /dev/null
+++ b/Documentation/devicetree/bindings/pinctrl/ti,iodelay.txt
@@ -0,0 +1,47 @@
+* Pin configuration for TI IODELAY controller
+
+TI dra7 based SoCs such as am57xx have a controller for setting the IO delay
+for each pin. For most part the IO delay values are programmed by the bootloader,
+but some pins need to be configured dynamically by the kernel such as the
+MMC pins.
+
+Required Properties:
+
+  - compatible: Must be "ti,dra7-iodelay"
+  - reg: Base address and length of the memory resource used
+  - #address-cells: Number of address cells
+  - #size-cells: Size of cells
+  - #pinctrl-cells: Number of pinctrl cells, must be 2. See also
+    Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
+
+Example
+-------
+
+In the SoC specific dtsi file:
+
+	dra7_iodelay_core: padconf@4844a000 {
+		compatible = "ti,dra7-iodelay";
+		reg = <0x4844a000 0x0d1c>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+		#pinctrl-cells = <2>;
+	};
+
+In board-specific file:
+
+&dra7_iodelay_core {
+	mmc2_iodelay_3v3_conf: mmc2_iodelay_3v3_conf {
+		pinctrl-pin-array = <
+		0x18c A_DELAY_PS(0) G_DELAY_PS(120)	/* CFG_GPMC_A19_IN */
+		0x1a4 A_DELAY_PS(265) G_DELAY_PS(360)	/* CFG_GPMC_A20_IN */
+		0x1b0 A_DELAY_PS(0) G_DELAY_PS(120)	/* CFG_GPMC_A21_IN */
+		0x1bc A_DELAY_PS(0) G_DELAY_PS(120)	/* CFG_GPMC_A22_IN */
+		0x1c8 A_DELAY_PS(287) G_DELAY_PS(420)	/* CFG_GPMC_A23_IN */
+		0x1d4 A_DELAY_PS(144) G_DELAY_PS(240)	/* CFG_GPMC_A24_IN */
+		0x1e0 A_DELAY_PS(0) G_DELAY_PS(0)	/* CFG_GPMC_A25_IN */
+		0x1ec A_DELAY_PS(120) G_DELAY_PS(0)	/* CFG_GPMC_A26_IN */
+		0x1f8 A_DELAY_PS(120) G_DELAY_PS(180)	/* CFG_GPMC_A27_IN */
+		0x360 A_DELAY_PS(0) G_DELAY_PS(0)	/* CFG_GPMC_CS1_IN */
+		>;
+	};
+};
diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig
--- a/drivers/pinctrl/Kconfig
+++ b/drivers/pinctrl/Kconfig
@@ -300,6 +300,7 @@ source "drivers/pinctrl/spear/Kconfig"
 source "drivers/pinctrl/stm32/Kconfig"
 source "drivers/pinctrl/sunxi/Kconfig"
 source "drivers/pinctrl/tegra/Kconfig"
+source "drivers/pinctrl/ti/Kconfig"
 source "drivers/pinctrl/uniphier/Kconfig"
 source "drivers/pinctrl/vt8500/Kconfig"
 source "drivers/pinctrl/mediatek/Kconfig"
diff --git a/drivers/pinctrl/Makefile b/drivers/pinctrl/Makefile
--- a/drivers/pinctrl/Makefile
+++ b/drivers/pinctrl/Makefile
@@ -53,6 +53,7 @@ obj-$(CONFIG_PINCTRL_SH_PFC)	+= sh-pfc/
 obj-$(CONFIG_PINCTRL_SPEAR)	+= spear/
 obj-$(CONFIG_PINCTRL_STM32)	+= stm32/
 obj-$(CONFIG_PINCTRL_SUNXI)	+= sunxi/
+obj-y				+= ti/
 obj-$(CONFIG_PINCTRL_UNIPHIER)	+= uniphier/
 obj-$(CONFIG_ARCH_VT8500)	+= vt8500/
 obj-$(CONFIG_PINCTRL_MTK)	+= mediatek/
diff --git a/drivers/pinctrl/ti/Kconfig b/drivers/pinctrl/ti/Kconfig
new file mode 100644
--- /dev/null
+++ b/drivers/pinctrl/ti/Kconfig
@@ -0,0 +1,10 @@
+config PINCTRL_TI_IODELAY
+	tristate "TI IODelay Module pinconf driver"
+	depends on OF
+	select GENERIC_PINCTRL_GROUPS
+	select GENERIC_PINMUX_FUNCTIONS
+	select GENERIC_PINCONF
+	select REGMAP_MMIO
+	help
+	  Say Y here to support Texas Instruments' IO delay pinconf driver.
+	  IO delay module is used for the DRA7 SoC family.
diff --git a/drivers/pinctrl/ti/Makefile b/drivers/pinctrl/ti/Makefile
new file mode 100644
--- /dev/null
+++ b/drivers/pinctrl/ti/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_PINCTRL_TI_IODELAY)	+= pinctrl-ti-iodelay.o
diff --git a/drivers/pinctrl/ti/pinctrl-ti-iodelay.c b/drivers/pinctrl/ti/pinctrl-ti-iodelay.c
new file mode 100644
--- /dev/null
+++ b/drivers/pinctrl/ti/pinctrl-ti-iodelay.c
@@ -0,0 +1,944 @@
+/*
+ * Support for configuration of IO Delay module found on Texas Instruments SoCs
+ * such as DRA7
+ *
+ * Copyright (C) 2015-2017 Texas Instruments Incorporated - http://www.ti.com/
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/pinctrl/pinconf.h>
+#include <linux/pinctrl/pinconf-generic.h>
+#include <linux/pinctrl/pinctrl.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+#include "../core.h"
+#include "../devicetree.h"
+
+#define DRIVER_NAME	"ti-iodelay"
+
+/**
+ * struct ti_iodelay_reg_data - Describes the registers for the iodelay instance
+ * @signature_mask: CONFIG_REG mask for the signature bits (see TRM)
+ * @signature_value: CONFIG_REG signature value to be written (see TRM)
+ * @lock_mask: CONFIG_REG mask for the lock bits (see TRM)
+ * @lock_val: CONFIG_REG lock value for the lock bits (see TRM)
+ * @unlock_val:CONFIG_REG unlock value for the lock bits (see TRM)
+ * @binary_data_coarse_mask: CONFIG_REG coarse mask (see TRM)
+ * @binary_data_fine_mask: CONFIG_REG fine mask (see TRM)
+ * @reg_refclk_offset: Refclk register offset
+ * @refclk_period_mask: Refclk mask
+ * @reg_coarse_offset: Coarse register configuration offset
+ * @coarse_delay_count_mask: Coarse delay count mask
+ * @coarse_ref_count_mask: Coarse ref count mask
+ * @reg_fine_offset: Fine register configuration offset
+ * @fine_delay_count_mask: Fine delay count mask
+ * @fine_ref_count_mask: Fine ref count mask
+ * @reg_global_lock_offset: Global iodelay module lock register offset
+ * @global_lock_mask: Lock mask
+ * @global_unlock_val: Unlock value
+ * @global_lock_val: Lock value
+ * @reg_start_offset: Offset to iodelay registers after the CONFIG_REG_0 to 8
+ * @reg_nr_per_pin: Number of iodelay registers for each pin
+ * @regmap_config: Regmap configuration for the IODelay region
+ */
+struct ti_iodelay_reg_data {
+	u32 signature_mask;
+	u32 signature_value;
+	u32 lock_mask;
+	u32 lock_val;
+	u32 unlock_val;
+	u32 binary_data_coarse_mask;
+	u32 binary_data_fine_mask;
+
+	u32 reg_refclk_offset;
+	u32 refclk_period_mask;
+
+	u32 reg_coarse_offset;
+	u32 coarse_delay_count_mask;
+	u32 coarse_ref_count_mask;
+
+	u32 reg_fine_offset;
+	u32 fine_delay_count_mask;
+	u32 fine_ref_count_mask;
+
+	u32 reg_global_lock_offset;
+	u32 global_lock_mask;
+	u32 global_unlock_val;
+	u32 global_lock_val;
+
+	u32 reg_start_offset;
+	u32 reg_nr_per_pin;
+
+	struct regmap_config *regmap_config;
+};
+
+/**
+ * struct ti_iodelay_reg_values - Computed io_reg configuration values (see TRM)
+ * @coarse_ref_count: Coarse reference count
+ * @coarse_delay_count: Coarse delay count
+ * @fine_ref_count: Fine reference count
+ * @fine_delay_count: Fine Delay count
+ * @ref_clk_period: Reference Clock period
+ * @cdpe: Coarse delay parameter
+ * @fdpe: Fine delay parameter
+ */
+struct ti_iodelay_reg_values {
+	u16 coarse_ref_count;
+	u16 coarse_delay_count;
+
+	u16 fine_ref_count;
+	u16 fine_delay_count;
+
+	u16 ref_clk_period;
+
+	u32 cdpe;
+	u32 fdpe;
+};
+
+/**
+ * struct ti_iodelay_cfg - Description of each configuration parameters
+ * @offset: Configuration register offset
+ * @a_delay: Agnostic Delay (in ps)
+ * @g_delay: Gnostic Delay (in ps)
+ */
+struct ti_iodelay_cfg {
+	u16 offset;
+	u16 a_delay;
+	u16 g_delay;
+};
+
+/**
+ * struct ti_iodelay_pingroup - Structure that describes one group
+ * @cfg: configuration array for the pin (from dt)
+ * @ncfg: number of configuration values allocated
+ * @config: pinconf "Config" - currently a dummy value
+ */
+struct ti_iodelay_pingroup {
+	struct ti_iodelay_cfg *cfg;
+	int ncfg;
+	unsigned long config;
+};
+
+/**
+ * struct ti_iodelay_device - Represents information for a iodelay instance
+ * @dev: Device pointer
+ * @phys_base: Physical address base of the iodelay device
+ * @reg_base: Virtual address base of the iodelay device
+ * @regmap: Regmap for this iodelay instance
+ * @pctl: Pinctrl device
+ * @desc: pinctrl descriptor for pctl
+ * @pa: pinctrl pin wise description
+ * @reg_data: Register definition data for the IODelay instance
+ * @reg_init_conf_values: Initial configuration values.
+ */
+struct ti_iodelay_device {
+	struct device *dev;
+	unsigned long phys_base;
+	void __iomem *reg_base;
+	struct regmap *regmap;
+
+	struct pinctrl_dev *pctl;
+	struct pinctrl_desc desc;
+	struct pinctrl_pin_desc *pa;
+
+	const struct ti_iodelay_reg_data *reg_data;
+	struct ti_iodelay_reg_values reg_init_conf_values;
+};
+
+/**
+ * ti_iodelay_extract() - extract bits for a field
+ * @val: Register value
+ * @mask: Mask
+ *
+ * Return: extracted value which is appropriately shifted
+ */
+static inline u32 ti_iodelay_extract(u32 val, u32 mask)
+{
+	return (val & mask) >> __ffs(mask);
+}
+
+/**
+ * ti_iodelay_compute_dpe() - Compute equation for delay parameter
+ * @period: Period to use
+ * @ref: Reference Count
+ * @delay: Delay count
+ * @delay_m: Delay multiplier
+ *
+ * Return: Computed delay parameter
+ */
+static inline u32 ti_iodelay_compute_dpe(u16 period, u16 ref, u16 delay,
+					 u16 delay_m)
+{
+	u64 m, d;
+
+	/* Handle overflow conditions */
+	m = 10 * (u64)period * (u64)ref;
+	d = 2 * (u64)delay * (u64)delay_m;
+
+	/* Truncate result back to 32 bits */
+	return div64_u64(m, d);
+}
+
+/**
+ * ti_iodelay_pinconf_set() - Configure the pin configuration
+ * @iod: iodelay device
+ * @cfg: Configuration
+ *
+ * Update the configuration register as per TRM and lockup once done.
+ * *IMPORTANT NOTE* SoC TRM does recommend doing iodelay programmation only
+ * while in Isolation. But, then, isolation also implies that every pin
+ * on the SoC (including DDR) will be isolated out. The only benefit being
+ * a glitchless configuration, However, the intent of this driver is purely
+ * to support a "glitchy" configuration where applicable.
+ *
+ * Return: 0 in case of success, else appropriate error value
+ */
+static int ti_iodelay_pinconf_set(struct ti_iodelay_device *iod,
+				  struct ti_iodelay_cfg *cfg)
+{
+	const struct ti_iodelay_reg_data *reg = iod->reg_data;
+	struct ti_iodelay_reg_values *ival = &iod->reg_init_conf_values;
+	struct device *dev = iod->dev;
+	u32 g_delay_coarse, g_delay_fine;
+	u32 a_delay_coarse, a_delay_fine;
+	u32 c_elements, f_elements;
+	u32 total_delay;
+	u32 reg_mask, reg_val, tmp_val;
+	int r;
+
+	/* NOTE: Truncation is expected in all division below */
+	g_delay_coarse = cfg->g_delay / 920;
+	g_delay_fine = ((cfg->g_delay % 920) * 10) / 60;
+
+	a_delay_coarse = cfg->a_delay / ival->cdpe;
+	a_delay_fine = ((cfg->a_delay % ival->cdpe) * 10) / ival->fdpe;
+
+	c_elements = g_delay_coarse + a_delay_coarse;
+	f_elements = (g_delay_fine + a_delay_fine) / 10;
+
+	if (f_elements > 22) {
+		total_delay = c_elements * ival->cdpe + f_elements * ival->fdpe;
+		c_elements = total_delay / ival->cdpe;
+		f_elements = (total_delay % ival->cdpe) / ival->fdpe;
+	}
+
+	reg_mask = reg->signature_mask;
+	reg_val = reg->signature_value << __ffs(reg->signature_mask);
+
+	reg_mask |= reg->binary_data_coarse_mask;
+	tmp_val = c_elements << __ffs(reg->binary_data_coarse_mask);
+	if (tmp_val & ~reg->binary_data_coarse_mask) {
+		dev_err(dev, "Masking overflow of coarse elements %08x\n",
+			tmp_val);
+		tmp_val &= reg->binary_data_coarse_mask;
+	}
+	reg_val |= tmp_val;
+
+	reg_mask |= reg->binary_data_fine_mask;
+	tmp_val = f_elements << __ffs(reg->binary_data_fine_mask);
+	if (tmp_val & ~reg->binary_data_fine_mask) {
+		dev_err(dev, "Masking overflow of fine elements %08x\n",
+			tmp_val);
+		tmp_val &= reg->binary_data_fine_mask;
+	}
+	reg_val |= tmp_val;
+
+	/*
+	 * NOTE: we leave the iodelay values unlocked - this is to work around
+	 * situations such as those found with mmc mode change.
+	 * However, this leaves open any unwarranted changes to padconf register
+	 * impacting iodelay configuration. Use with care!
+	 */
+	reg_mask |= reg->lock_mask;
+	reg_val |= reg->unlock_val << __ffs(reg->lock_mask);
+	r = regmap_update_bits(iod->regmap, cfg->offset, reg_mask, reg_val);
+
+	dev_info(dev, "Set reg 0x%x Delay(a: %d g: %d), Elements(C=%d F=%d)0x%x\n",
+		 cfg->offset, cfg->a_delay, cfg->g_delay, c_elements,
+		 f_elements, reg_val);
+
+	return r;
+}
+
+/**
+ * ti_iodelay_pinconf_init_dev() - Initialize IODelay device
+ * @iod: iodelay device
+ *
+ * Unlocks the iodelay region, computes the common parameters
+ *
+ * Return: 0 in case of success, else appropriate error value
+ */
+static int ti_iodelay_pinconf_init_dev(struct ti_iodelay_device *iod)
+{
+	const struct ti_iodelay_reg_data *reg = iod->reg_data;
+	struct device *dev = iod->dev;
+	struct ti_iodelay_reg_values *ival = &iod->reg_init_conf_values;
+	u32 val;
+	int r;
+
+	/* unlock the iodelay region */
+	r = regmap_update_bits(iod->regmap, reg->reg_global_lock_offset,
+			       reg->global_lock_mask, reg->global_unlock_val);
+	if (r)
+		return r;
+
+	/* Read up Recalibration sequence done by bootloader */
+	r = regmap_read(iod->regmap, reg->reg_refclk_offset, &val);
+	if (r)
+		return r;
+	ival->ref_clk_period = ti_iodelay_extract(val, reg->refclk_period_mask);
+	dev_dbg(dev, "refclk_period=0x%04x\n", ival->ref_clk_period);
+
+	r = regmap_read(iod->regmap, reg->reg_coarse_offset, &val);
+	if (r)
+		return r;
+	ival->coarse_ref_count =
+	    ti_iodelay_extract(val, reg->coarse_ref_count_mask);
+	ival->coarse_delay_count =
+	    ti_iodelay_extract(val, reg->coarse_delay_count_mask);
+	if (!ival->coarse_delay_count) {
+		dev_err(dev, "Invalid Coarse delay count (0) (reg=0x%08x)\n",
+			val);
+		return -EINVAL;
+	}
+	ival->cdpe = ti_iodelay_compute_dpe(ival->ref_clk_period,
+					    ival->coarse_ref_count,
+					    ival->coarse_delay_count, 88);
+	if (!ival->cdpe) {
+		dev_err(dev, "Invalid cdpe computed params = %d %d %d\n",
+			ival->ref_clk_period, ival->coarse_ref_count,
+			ival->coarse_delay_count);
+		return -EINVAL;
+	}
+	dev_dbg(iod->dev, "coarse: ref=0x%04x delay=0x%04x cdpe=0x%08x\n",
+		ival->coarse_ref_count, ival->coarse_delay_count, ival->cdpe);
+
+	r = regmap_read(iod->regmap, reg->reg_fine_offset, &val);
+	if (r)
+		return r;
+	ival->fine_ref_count =
+	    ti_iodelay_extract(val, reg->fine_ref_count_mask);
+	ival->fine_delay_count =
+	    ti_iodelay_extract(val, reg->fine_delay_count_mask);
+	if (!ival->fine_delay_count) {
+		dev_err(dev, "Invalid Fine delay count (0) (reg=0x%08x)\n",
+			val);
+		return -EINVAL;
+	}
+	ival->fdpe = ti_iodelay_compute_dpe(ival->ref_clk_period,
+					    ival->fine_ref_count,
+					    ival->fine_delay_count, 264);
+	if (!ival->fdpe) {
+		dev_err(dev, "Invalid fdpe(0) computed params = %d %d %d\n",
+			ival->ref_clk_period, ival->fine_ref_count,
+			ival->fine_delay_count);
+		return -EINVAL;
+	}
+	dev_dbg(iod->dev, "fine: ref=0x%04x delay=0x%04x fdpe=0x%08x\n",
+		ival->fine_ref_count, ival->fine_delay_count, ival->fdpe);
+
+	return 0;
+}
+
+/**
+ * ti_iodelay_pinconf_deinit_dev() - deinit the iodelay device
+ * @iod:	IODelay device
+ *
+ * Deinitialize the IODelay device (basically just lock the region back up.
+ */
+static void ti_iodelay_pinconf_deinit_dev(struct ti_iodelay_device *iod)
+{
+	const struct ti_iodelay_reg_data *reg = iod->reg_data;
+
+	/* lock the iodelay region back again */
+	regmap_update_bits(iod->regmap, reg->reg_global_lock_offset,
+			   reg->global_lock_mask, reg->global_lock_val);
+}
+
+/**
+ * ti_iodelay_get_pingroup() - Find the group mapped by a group selector
+ * @iod: iodelay device
+ * @selector: Group Selector
+ *
+ * Return: Corresponding group representing group selector
+ */
+static struct ti_iodelay_pingroup *
+ti_iodelay_get_pingroup(struct ti_iodelay_device *iod, unsigned int selector)
+{
+	struct group_desc *g;
+
+	g = pinctrl_generic_get_group(iod->pctl, selector);
+	if (!g) {
+		dev_err(iod->dev, "%s could not find pingroup %i\n", __func__,
+			selector);
+
+		return NULL;
+	}
+
+	return g->data;
+}
+
+/**
+ * ti_iodelay_offset_to_pin() - get a pin index based on the register offset
+ * @iod: iodelay driver instance
+ * @offset: register offset from the base
+ */
+static int ti_iodelay_offset_to_pin(struct ti_iodelay_device *iod,
+				    unsigned int offset)
+{
+	const struct ti_iodelay_reg_data *r = iod->reg_data;
+	unsigned int index;
+
+	if (offset > r->regmap_config->max_register) {
+		dev_err(iod->dev, "mux offset out of range: 0x%x (0x%x)\n",
+			offset, r->regmap_config->max_register);
+		return -EINVAL;
+	}
+
+	index = (offset - r->reg_start_offset) / r->regmap_config->reg_stride;
+	index /= r->reg_nr_per_pin;
+
+	return index;
+}
+
+/**
+ * ti_iodelay_node_iterator() - Iterate iodelay node
+ * @pctldev: Pin controller driver
+ * @np: Device node
+ * @pinctrl_spec: Parsed arguments from device tree
+ * @pins: Array of pins in the pin group
+ * @pin_index: Pin index in the pin array
+ * @data: Pin controller driver specific data
+ *
+ */
+static int ti_iodelay_node_iterator(struct pinctrl_dev *pctldev,
+				    struct device_node *np,
+				    const struct of_phandle_args *pinctrl_spec,
+				    int *pins, int pin_index, void *data)
+{
+	struct ti_iodelay_device *iod;
+	struct ti_iodelay_cfg *cfg = data;
+	const struct ti_iodelay_reg_data *r;
+	struct pinctrl_pin_desc *pd;
+	int pin;
+
+	iod = pinctrl_dev_get_drvdata(pctldev);
+	if (!iod)
+		return -EINVAL;
+
+	r = iod->reg_data;
+
+	if (pinctrl_spec->args_count < r->reg_nr_per_pin) {
+		dev_err(iod->dev, "invalid args_count for spec: %i\n",
+			pinctrl_spec->args_count);
+
+		return -EINVAL;
+	}
+
+	/* Index plus two value cells */
+	cfg[pin_index].offset = pinctrl_spec->args[0];
+	cfg[pin_index].a_delay = pinctrl_spec->args[1] & 0xffff;
+	cfg[pin_index].g_delay = pinctrl_spec->args[2] & 0xffff;
+
+	pin = ti_iodelay_offset_to_pin(iod, cfg[pin_index].offset);
+	if (pin < 0) {
+		dev_err(iod->dev, "could not add functions for %s %ux\n",
+			np->name, cfg[pin_index].offset);
+		return -ENODEV;
+	}
+	pins[pin_index] = pin;
+
+	pd = &iod->pa[pin];
+	pd->drv_data = &cfg[pin_index];
+
+	dev_dbg(iod->dev, "%s offset=%x a_delay = %d g_delay = %d\n",
+		np->name, cfg[pin_index].offset, cfg[pin_index].a_delay,
+		cfg[pin_index].g_delay);
+
+	return 0;
+}
+
+/**
+ * ti_iodelay_dt_node_to_map() - Map a device tree node to appropriate group
+ * @pctldev: pinctrl device representing IODelay device
+ * @np: Node Pointer (device tree)
+ * @map: Pinctrl Map returned back to pinctrl framework
+ * @num_maps: Number of maps (1)
+ *
+ * Maps the device tree description into a group of configuration parameters
+ * for iodelay block entry.
+ *
+ * Return: 0 in case of success, else appropriate error value
+ */
+static int ti_iodelay_dt_node_to_map(struct pinctrl_dev *pctldev,
+				     struct device_node *np,
+				     struct pinctrl_map **map,
+				     unsigned int *num_maps)
+{
+	struct ti_iodelay_device *iod;
+	struct ti_iodelay_cfg *cfg;
+	struct ti_iodelay_pingroup *g;
+	const char *name = "pinctrl-pin-array";
+	int rows, *pins, error = -EINVAL, i;
+
+	iod = pinctrl_dev_get_drvdata(pctldev);
+	if (!iod)
+		return -EINVAL;
+
+	rows = pinctrl_count_index_with_args(np, name);
+	if (rows == -EINVAL)
+		return rows;
+
+	*map = devm_kzalloc(iod->dev, sizeof(**map), GFP_KERNEL);
+	if (!*map)
+		return -ENOMEM;
+	*num_maps = 0;
+
+	g = devm_kzalloc(iod->dev, sizeof(*g), GFP_KERNEL);
+	if (!g) {
+		error = -ENOMEM;
+		goto free_map;
+	}
+
+	pins = devm_kzalloc(iod->dev, sizeof(*pins) * rows, GFP_KERNEL);
+	if (!pins)
+		goto free_group;
+
+	cfg = devm_kzalloc(iod->dev, sizeof(*cfg) * rows, GFP_KERNEL);
+	if (!cfg) {
+		error = -ENOMEM;
+		goto free_pins;
+	}
+
+	for (i = 0; i < rows; i++) {
+		struct of_phandle_args pinctrl_spec;
+
+		error = pinctrl_parse_index_with_args(np, name, i,
+						      &pinctrl_spec);
+		if (error)
+			goto free_data;
+
+		error = ti_iodelay_node_iterator(pctldev, np, &pinctrl_spec,
+						 pins, i, cfg);
+		if (error)
+			goto free_data;
+	}
+
+	g->cfg = cfg;
+	g->ncfg = i;
+	g->config = PIN_CONFIG_END;
+
+	error = pinctrl_generic_add_group(iod->pctl, np->name, pins, i, g);
+	if (error < 0)
+		goto free_data;
+
+	(*map)->type = PIN_MAP_TYPE_CONFIGS_GROUP;
+	(*map)->data.configs.group_or_pin = np->name;
+	(*map)->data.configs.configs = &g->config;
+	(*map)->data.configs.num_configs = 1;
+	*num_maps = 1;
+
+	return 0;
+
+free_data:
+	devm_kfree(iod->dev, cfg);
+free_pins:
+	devm_kfree(iod->dev, pins);
+free_group:
+	devm_kfree(iod->dev, g);
+free_map:
+	devm_kfree(iod->dev, *map);
+
+	return error;
+}
+
+/**
+ * ti_iodelay_pinconf_group_get() - Get the group configuration
+ * @pctldev: pinctrl device representing IODelay device
+ * @selector: Group selector
+ * @config: Configuration returned
+ *
+ * Return: The configuration if the group is valid, else returns -EINVAL
+ */
+static int ti_iodelay_pinconf_group_get(struct pinctrl_dev *pctldev,
+					unsigned int selector,
+					unsigned long *config)
+{
+	struct ti_iodelay_device *iod;
+	struct device *dev;
+	struct ti_iodelay_pingroup *group;
+
+	iod = pinctrl_dev_get_drvdata(pctldev);
+	dev = iod->dev;
+	group = ti_iodelay_get_pingroup(iod, selector);
+
+	if (!group)
+		return -EINVAL;
+
+	*config = group->config;
+	return 0;
+}
+
+/**
+ * ti_iodelay_pinconf_group_set() - Configure the groups of pins
+ * @pctldev: pinctrl device representing IODelay device
+ * @selector: Group selector
+ * @configs: Configurations
+ * @num_configs: Number of configurations
+ *
+ * Return: 0 if all went fine, else appropriate error value.
+ */
+static int ti_iodelay_pinconf_group_set(struct pinctrl_dev *pctldev,
+					unsigned int selector,
+					unsigned long *configs,
+					unsigned int num_configs)
+{
+	struct ti_iodelay_device *iod;
+	struct device *dev;
+	struct ti_iodelay_pingroup *group;
+	int i;
+
+	iod = pinctrl_dev_get_drvdata(pctldev);
+	dev = iod->dev;
+	group = ti_iodelay_get_pingroup(iod, selector);
+
+	if (num_configs != 1) {
+		dev_err(dev, "Unsupported number of configurations %d\n",
+			num_configs);
+		return -EINVAL;
+	}
+
+	if (*configs != PIN_CONFIG_END) {
+		dev_err(dev, "Unsupported configuration\n");
+		return -EINVAL;
+	}
+
+	for (i = 0; i < group->ncfg; i++) {
+		if (ti_iodelay_pinconf_set(iod, &group->cfg[i]))
+			return -ENOTSUPP;
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_DEBUG_FS
+/**
+ * ti_iodelay_pin_to_offset() - get pin register offset based on the pin index
+ * @iod: iodelay driver instance
+ * @selector: Pin index
+ */
+static unsigned int ti_iodelay_pin_to_offset(struct ti_iodelay_device *iod,
+					     unsigned int selector)
+{
+	const struct ti_iodelay_reg_data *r = iod->reg_data;
+	unsigned int offset;
+
+	offset = selector * r->regmap_config->reg_stride;
+	offset *= r->reg_nr_per_pin;
+	offset += r->reg_start_offset;
+
+	return offset;
+}
+
+static void ti_iodelay_pin_dbg_show(struct pinctrl_dev *pctldev,
+				    struct seq_file *s,
+				    unsigned int pin)
+{
+	struct ti_iodelay_device *iod;
+	struct pinctrl_pin_desc *pd;
+	struct ti_iodelay_cfg *cfg;
+	const struct ti_iodelay_reg_data *r;
+	unsigned long offset;
+	u32 in, oen, out;
+
+	iod = pinctrl_dev_get_drvdata(pctldev);
+	r = iod->reg_data;
+
+	offset = ti_iodelay_pin_to_offset(iod, pin);
+	if (pin < 0) {
+		dev_err(iod->dev, "invalid pin offset for pin%i\n", pin);
+
+		return;
+	}
+
+	pd = &iod->pa[pin];
+	cfg = pd->drv_data;
+
+	regmap_read(iod->regmap, offset, &in);
+	regmap_read(iod->regmap, offset + r->regmap_config->reg_stride, &oen);
+	regmap_read(iod->regmap, offset + r->regmap_config->reg_stride * 2,
+		    &out);
+
+	seq_printf(s, "%lx a: %i g: %i (%08x %08x %08x) %s ",
+		   iod->phys_base + offset,
+		   cfg ? cfg->a_delay : -1,
+		   cfg ? cfg->g_delay : -1,
+		   in, oen, out, DRIVER_NAME);
+}
+
+/**
+ * ti_iodelay_pinconf_group_dbg_show() - show the group information
+ * @pctldev: Show the group information
+ * @s: Sequence file
+ * @selector: Group selector
+ *
+ * Provide the configuration information of the selected group
+ */
+static void ti_iodelay_pinconf_group_dbg_show(struct pinctrl_dev *pctldev,
+					      struct seq_file *s,
+					      unsigned int selector)
+{
+	struct ti_iodelay_device *iod;
+	struct device *dev;
+	struct ti_iodelay_pingroup *group;
+	int i;
+
+	iod = pinctrl_dev_get_drvdata(pctldev);
+	dev = iod->dev;
+	group = ti_iodelay_get_pingroup(iod, selector);
+	if (!group)
+		return;
+
+	for (i = 0; i < group->ncfg; i++) {
+		struct ti_iodelay_cfg *cfg;
+		u32 reg = 0;
+
+		cfg = &group->cfg[i];
+		regmap_read(iod->regmap, cfg->offset, &reg),
+			seq_printf(s, "\n\t0x%08x = 0x%08x (%3d, %3d)",
+				   cfg->offset, reg, cfg->a_delay,
+				   cfg->g_delay);
+	}
+}
+#endif
+
+static struct pinctrl_ops ti_iodelay_pinctrl_ops = {
+	.get_groups_count = pinctrl_generic_get_group_count,
+	.get_group_name = pinctrl_generic_get_group_name,
+	.get_group_pins = pinctrl_generic_get_group_pins,
+#ifdef CONFIG_DEBUG_FS
+	.pin_dbg_show = ti_iodelay_pin_dbg_show,
+#endif
+	.dt_node_to_map = ti_iodelay_dt_node_to_map,
+};
+
+static struct pinconf_ops ti_iodelay_pinctrl_pinconf_ops = {
+	.pin_config_group_get = ti_iodelay_pinconf_group_get,
+	.pin_config_group_set = ti_iodelay_pinconf_group_set,
+#ifdef CONFIG_DEBUG_FS
+	.pin_config_group_dbg_show = ti_iodelay_pinconf_group_dbg_show,
+#endif
+};
+
+/**
+ * ti_iodelay_alloc_pins() - Allocate structures needed for pins for iodelay
+ * @dev: Device pointer
+ * @iod: iodelay device
+ * @base_phy: Base Physical Address
+ *
+ * Return: 0 if all went fine, else appropriate error value.
+ */
+static int ti_iodelay_alloc_pins(struct device *dev,
+				 struct ti_iodelay_device *iod, u32 base_phy)
+{
+	const struct ti_iodelay_reg_data *r = iod->reg_data;
+	struct pinctrl_pin_desc *pin;
+	u32 phy_reg;
+	int nr_pins, i;
+
+	nr_pins = ti_iodelay_offset_to_pin(iod, r->regmap_config->max_register);
+	dev_dbg(dev, "Allocating %i pins\n", nr_pins);
+
+	iod->pa = devm_kzalloc(dev, sizeof(*iod->pa) * nr_pins, GFP_KERNEL);
+	if (!iod->pa)
+		return -ENOMEM;
+
+	iod->desc.pins = iod->pa;
+	iod->desc.npins = nr_pins;
+
+	phy_reg = r->reg_start_offset + base_phy;
+
+	for (i = 0; i < nr_pins; i++, phy_reg += 4) {
+		pin = &iod->pa[i];
+		pin->number = i;
+	}
+
+	return 0;
+}
+
+static struct regmap_config dra7_iodelay_regmap_config = {
+	.reg_bits = 32,
+	.reg_stride = 4,
+	.val_bits = 32,
+	.max_register = 0xd1c,
+};
+
+static struct ti_iodelay_reg_data dra7_iodelay_data = {
+	.signature_mask = 0x0003f000,
+	.signature_value = 0x29,
+	.lock_mask = 0x00000400,
+	.lock_val = 1,
+	.unlock_val = 0,
+	.binary_data_coarse_mask = 0x000003e0,
+	.binary_data_fine_mask = 0x0000001f,
+
+	.reg_refclk_offset = 0x14,
+	.refclk_period_mask = 0xffff,
+
+	.reg_coarse_offset = 0x18,
+	.coarse_delay_count_mask = 0xffff0000,
+	.coarse_ref_count_mask = 0x0000ffff,
+
+	.reg_fine_offset = 0x1C,
+	.fine_delay_count_mask = 0xffff0000,
+	.fine_ref_count_mask = 0x0000ffff,
+
+	.reg_global_lock_offset = 0x2c,
+	.global_lock_mask = 0x0000ffff,
+	.global_unlock_val = 0x0000aaaa,
+	.global_lock_val = 0x0000aaab,
+
+	.reg_start_offset = 0x30,
+	.reg_nr_per_pin = 3,
+	.regmap_config = &dra7_iodelay_regmap_config,
+};
+
+static const struct of_device_id ti_iodelay_of_match[] = {
+	{.compatible = "ti,dra7-iodelay", .data = &dra7_iodelay_data},
+	{ /* Hopefully no more.. */ },
+};
+MODULE_DEVICE_TABLE(of, ti_iodelay_of_match);
+
+/**
+ * ti_iodelay_probe() - Standard probe
+ * @pdev: platform device
+ *
+ * Return: 0 if all went fine, else appropriate error value.
+ */
+static int ti_iodelay_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = of_node_get(dev->of_node);
+	const struct of_device_id *match;
+	struct resource *res;
+	struct ti_iodelay_device *iod;
+	int ret = 0;
+
+	if (!np) {
+		ret = -EINVAL;
+		dev_err(dev, "No OF node\n");
+		goto exit_out;
+	}
+
+	match = of_match_device(ti_iodelay_of_match, dev);
+	if (!match) {
+		ret = -EINVAL;
+		dev_err(dev, "No DATA match\n");
+		goto exit_out;
+	}
+
+	iod = devm_kzalloc(dev, sizeof(*iod), GFP_KERNEL);
+	if (!iod) {
+		ret = -ENOMEM;
+		goto exit_out;
+	}
+	iod->dev = dev;
+	iod->reg_data = match->data;
+
+	/* So far We can assume there is only 1 bank of registers */
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(dev, "Missing MEM resource\n");
+		ret = -ENODEV;
+		goto exit_out;
+	}
+
+	iod->phys_base = res->start;
+	iod->reg_base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(iod->reg_base)) {
+		ret = PTR_ERR(iod->reg_base);
+		goto exit_out;
+	}
+
+	iod->regmap = devm_regmap_init_mmio(dev, iod->reg_base,
+					    iod->reg_data->regmap_config);
+	if (IS_ERR(iod->regmap)) {
+		dev_err(dev, "Regmap MMIO init failed.\n");
+		ret = PTR_ERR(iod->regmap);
+		goto exit_out;
+	}
+
+	if (ti_iodelay_pinconf_init_dev(iod))
+		goto exit_out;
+
+	ret = ti_iodelay_alloc_pins(dev, iod, res->start);
+	if (ret)
+		goto exit_out;
+
+	iod->desc.pctlops = &ti_iodelay_pinctrl_ops;
+	/* no pinmux ops - we are pinconf */
+	iod->desc.confops = &ti_iodelay_pinctrl_pinconf_ops;
+	iod->desc.name = dev_name(dev);
+	iod->desc.owner = THIS_MODULE;
+
+	iod->pctl = pinctrl_register(&iod->desc, dev, iod);
+	if (!iod->pctl) {
+		dev_err(dev, "Failed to register pinctrl\n");
+		ret = -ENODEV;
+		goto exit_out;
+	}
+
+	platform_set_drvdata(pdev, iod);
+
+exit_out:
+	of_node_put(np);
+	return ret;
+}
+
+/**
+ * ti_iodelay_remove() - standard remove
+ * @pdev: platform device
+ *
+ * Return: 0 if all went fine, else appropriate error value.
+ */
+static int ti_iodelay_remove(struct platform_device *pdev)
+{
+	struct ti_iodelay_device *iod = platform_get_drvdata(pdev);
+
+	if (!iod)
+		return 0;
+
+	if (iod->pctl)
+		pinctrl_unregister(iod->pctl);
+
+	ti_iodelay_pinconf_deinit_dev(iod);
+
+	/* Expect other allocations to be freed by devm */
+
+	return 0;
+}
+
+static struct platform_driver ti_iodelay_driver = {
+	.probe = ti_iodelay_probe,
+	.remove = ti_iodelay_remove,
+	.driver = {
+		   .owner = THIS_MODULE,
+		   .name = DRIVER_NAME,
+		   .of_match_table = ti_iodelay_of_match,
+	},
+};
+module_platform_driver(ti_iodelay_driver);
+
+MODULE_AUTHOR("Texas Instruments, Inc.");
+MODULE_DESCRIPTION("Pinconf driver for TI's IO Delay module");
+MODULE_LICENSE("GPL v2");
-- 
2.11.0
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Re: [PATCH 2/2] pinctrl: Introduce TI IOdelay configuration driver

[Linus Walleij]

On Thu, Jan 5, 2017 at 7:54 PM, Tony Lindgren <tony@atomide.com> wrote:

> From: Nishanth Menon <nm@ti.com>
>
> SoC family such as DRA7 family of processors have, in addition
> to the regular muxing of pins (as done by pinctrl-single), a separate
> hardware module called IODelay which is also expected to be configured.
> The "IODelay" module has it's own register space that is independent
> of the control module and the padconf register area.
>
> With recent changes to the pinctrl framework, we can now support
> this hardware with a reasonably minimal driver by using #pinctrl-cells,
> GENERIC_PINCTRL_GROUPS and GENERIC_PINMUX_FUNCTIONS.
>
> It is advocated strongly in TI's official documentation considering
> the existing design of the DRA7 family of processors during mux or
> IODelay reconfiguration, there is a potential for a significant glitch
> which may cause functional impairment to certain hardware. It is
> hence recommended to do as little of muxing as absolutely necessary
> without I/O isolation (which can only be done in initial stages of
> bootloader).
>
> NOTE: with the system wide I/O isolation scheme present in DRA7 SoC
> family, it is not reasonable to do stop all I/O operations for every
> such pad configuration scheme. So, we will let it glitch when used in
> this mode.
>
> Even with the above limitation, certain functionality such as MMC has
> mandatory need for IODelay reconfiguration requirements, depending on
> speed of transfer. In these cases, with careful examination of usecase
> involved, the expected glitch can be controlled such that it does not
> impact functionality.
>
> In short, IODelay module support as a padconf driver being introduced
> here is not expected to do SoC wide I/O Isolation and is meant for
> a limited subset of IODelay configuration requirements that need to
> be dynamic and whose glitchy behavior will not cause functionality
> failure for that interface.
>
> IMPORTANT NOTE: we take the approach of keeping LOCK_BITs cleared
> to 0x0 at all times, even when configuring Manual IO Timing Modes.
> This is done by eliminating the LOCK_BIT=1 setting from Step
> of the Manual IO timing Mode configuration procedure. This option
> leaves the CFG_* registers unprotected from unintended writes to the
> CTRL_CORE_PAD_* registers while Manual IO Timing Modes are configured.
>
> This approach is taken to allow for a generic driver to exist in kernel
> world that has to be used carefully in required usecases.
>
> Signed-off-by: Nishanth Menon <nm@ti.com>
> Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
> [tony@atomide.com: updated to use generic pinctrl functions, added
>  binding documentation, updated comments]
> Acked-by: Rob Herring <robh@kernel.org>
> Signed-off-by: Tony Lindgren <tony@atomide.com>

Oh what a hardware mess. But very nicely isolated now.
Patch applied!

Yours,
Linus Walleij

[PATCH 0/2] pinctrl: Introduce support for iodelay module in TI SoCs

[Nishanth Menon]

Hi,

SoCs such as DRA7 family from Texas Instruments also include a highly
configurable hardware block called the IOdelay block. This block
allows very specific custom fine tuning for electrical characteristics
of IO pins that are necessary for functionality and device lifetime
requirements.

IODelay module exists on it's own register space with registers
allocated for various pins. A set of values (derived from either
automated tools OR from device datasheet) is then computed on a
per-chip basis(to account for die specific variations) to generate a
set of delay parameters that are programmed to one or more registers
for the delay path of the io line. This is used in specific instances
such as MMC to achieve high-throughput modes, and most pins dont
usually need tweaking functionality provided by this driver.

Even though this kind of operates similar to a pinctrl model,
functionally, it is a characteristics tuning which does not completely
fit the standard pinconf model either.

In addition to the regular pin muxing modes supported by the
pinctrl-single, additional configuration for this block for specific
pins may also be mandatory in certain cases.

Series based on v4.0-rc1

Nishanth Menon (2):
  pinctrl: bindings: pinctrl: Add support for TI's IODelay
    configuration
  pinctrl: Introduce TI IOdelay configuration driver

 .../bindings/pinctrl/ti,iodelay-pinctrl.txt        |   86 ++
 drivers/pinctrl/Kconfig                            |   11 +
 drivers/pinctrl/Makefile                           |    1 +
 drivers/pinctrl/pinctrl-ti-iodelay.c               |  963 ++++++++++++++++++++
 include/dt-bindings/pinctrl/dra.h                  |    6 +
 5 files changed, 1067 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pinctrl/ti,iodelay-pinctrl.txt
 create mode 100644 drivers/pinctrl/pinctrl-ti-iodelay.c

-- 
1.7.9.5

[PATCH 2/2] pinctrl: Introduce TI IOdelay configuration driver

[Nishanth Menon]

SoC family such as DRA7 family of processors have, in addition
to the regular muxing of pins (as done by pinctrl-single), an
additional hardware module called IODelay which is also expected to be
configured. This "IODelay" module has it's own register space that is
independent of the control module.

It is advocated strongly in TI's official documentation considering
the existing design of the DRA7 family of processors during mux or
IODelay reconfiguration, there is a potential for a significant glitch
which may cause functional impairment to certain hardware. It is
hence recommended to do as little of muxing as absolutely necessary
without I/O isolation (which can only be done in initial stages of
bootloader).

NOTE: with the system wide I/O isolation scheme present in DRA7 SoC
family, it is not reasonable to do stop all I/O operations for every
such pad configuration scheme. So, we will let it glitch when used in
this mode.

Even with the above limitation, certain functionality such as MMC has
mandatory need for IODelay reconfiguration requirements, depending on
speed of transfer. In these cases, with careful examination of usecase
involved, the expected glitch can be controlled such that it does not
impact functionality.

In short, IODelay module support as a padconf driver being introduced
here is not expected to do SoC wide I/O Isolation and is meant for
a limited subset of IODelay configuration requirements that need to
be dynamic and whose glitchy behavior will not cause functionality
failure for that interface.

Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
---
 drivers/pinctrl/Kconfig              |   11 +
 drivers/pinctrl/Makefile             |    1 +
 drivers/pinctrl/pinctrl-ti-iodelay.c |  963 ++++++++++++++++++++++++++++++++++
 include/dt-bindings/pinctrl/dra.h    |    6 +
 4 files changed, 981 insertions(+)
 create mode 100644 drivers/pinctrl/pinctrl-ti-iodelay.c

diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig
index ee9f44ad7f02..8e463d75fbb2 100644
--- a/drivers/pinctrl/Kconfig
+++ b/drivers/pinctrl/Kconfig
@@ -160,6 +160,17 @@ config PINCTRL_TEGRA_XUSB
 	select PINCONF
 	select PINMUX
 
+config PINCTRL_TI_IODELAY
+	bool "TI IODelay Module pinconf driver"
+	depends on OF
+	select PINCONF
+	select GENERIC_PINCONF
+	select REGMAP_MMIO
+	help
+	  Say Y here to support Texas Instruments' IODelay pinconf driver.
+	  IODelay module is used for the DRA7 SoC family. This driver is in
+	  addition to PINCTRL_SINGLE which controls the mux.
+
 config PINCTRL_TZ1090
 	bool "Toumaz Xenif TZ1090 pin control driver"
 	depends on SOC_TZ1090
diff --git a/drivers/pinctrl/Makefile b/drivers/pinctrl/Makefile
index 0475206dd600..e441cd71aedf 100644
--- a/drivers/pinctrl/Makefile
+++ b/drivers/pinctrl/Makefile
@@ -28,6 +28,7 @@ obj-$(CONFIG_PINCTRL_TEGRA30)	+= pinctrl-tegra30.o
 obj-$(CONFIG_PINCTRL_TEGRA114)	+= pinctrl-tegra114.o
 obj-$(CONFIG_PINCTRL_TEGRA124)	+= pinctrl-tegra124.o
 obj-$(CONFIG_PINCTRL_TEGRA_XUSB)	+= pinctrl-tegra-xusb.o
+obj-$(CONFIG_PINCTRL_TI_IODELAY)	+= pinctrl-ti-iodelay.o
 obj-$(CONFIG_PINCTRL_TZ1090)	+= pinctrl-tz1090.o
 obj-$(CONFIG_PINCTRL_TZ1090_PDC)	+= pinctrl-tz1090-pdc.o
 obj-$(CONFIG_PINCTRL_U300)	+= pinctrl-u300.o
diff --git a/drivers/pinctrl/pinctrl-ti-iodelay.c b/drivers/pinctrl/pinctrl-ti-iodelay.c
new file mode 100644
index 000000000000..e4c6e25a781c
--- /dev/null
+++ b/drivers/pinctrl/pinctrl-ti-iodelay.c
@@ -0,0 +1,963 @@
+/*
+ * Support for configuration of IO Delay module found on Texas Instruments SoCs
+ * such as DRA7
+ *
+ * Copyright (C) 2015 Texas Instruments, Inc.
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/of.h>
+#include <linux/pinctrl/pinconf-generic.h>
+#include <linux/pinctrl/pinconf.h>
+#include <linux/pinctrl/pinctrl.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+#define IODELAY_REG_NAME_LEN		((sizeof(u32) * 2) + 3)
+#define DRIVER_NAME			"ti-io-delay"
+/* Should I change this? Abuse? */
+#define IODELAY_MUX_PINS_NAME		"pinctrl-single,pins"
+
+/* Device tree match, populated later */
+static const struct of_device_id ti_iodelay_of_match[];
+
+/**
+ * struct ti_iodelay_conf_vals - Description of each configuration parameters.
+ * @offset:	Configuration register offset
+ * @a_delay:	Agnostic Delay (in ps)
+ * @g_delay:	Gnostic Delay (in ps)
+ */
+struct ti_iodelay_conf_vals {
+	u16 offset;
+	u16 a_delay;
+	u16 g_delay;
+};
+
+/**
+ * struct ti_iodelay_reg_data - Describes the registers for the IOdelay instance
+ * @signature_mask:	Conf reg- mask for the signature bits
+ * @signature_value:	Conf reg- signature value to be written (see TRM)
+ * @lock_mask:		Conf reg- mask for the lock bits
+ * @lock_val:		Conf reg- lock value for the lock bits (see TRM)
+ * @unlock_val:		Conf reg- unlock value for the lock bits (see TRM)
+ * @binary_data_coarse_mask: Conf reg- coarse mask (see TRM)
+ * @binary_data_fine_mask: Conf reg- fine mask (see TRM)
+ * @reg_refclk_offset:	Refclk register offset
+ * @refclk_period_mask:	Refclk mask
+ * @reg_coarse_offset:	Coarse register configuration offset
+ * @coarse_delay_count_mask: Coarse delay count mask
+ * @coarse_ref_count_mask: Coarse ref count mask
+ * @reg_fine_offset:	Fine register configuration offset
+ * @fine_delay_count_mask: Fine delay count mask
+ * @fine_ref_count_mask: Fine  ref count mask
+ * @reg_global_lock_offset: Global(for the IOdelay module) lock register offset
+ * @global_lock_mask:	Lock mask
+ * @global_unlock_val:	unlock value
+ * @global_lock_val:	lock value
+ * @reg_start_offset:	Where does the configuration registers start?
+ * @regmap_config:	Regmap configuration for the IODelay region
+ */
+struct ti_iodelay_reg_data {
+	u32 signature_mask;
+	u32 signature_value;
+	u32 lock_mask;
+	u32 lock_val;
+	u32 unlock_val;
+	u32 binary_data_coarse_mask;
+	u32 binary_data_fine_mask;
+
+	u32 reg_refclk_offset;
+	u32 refclk_period_mask;
+
+	u32 reg_coarse_offset;
+	u32 coarse_delay_count_mask;
+	u32 coarse_ref_count_mask;
+
+	u32 reg_fine_offset;
+	u32 fine_delay_count_mask;
+	u32 fine_ref_count_mask;
+
+	u32 reg_global_lock_offset;
+	u32 global_lock_mask;
+	u32 global_unlock_val;
+	u32 global_lock_val;
+
+	u32 reg_start_offset;
+
+	struct regmap_config *regmap_config;
+};
+
+/**
+ * struct ti_iodelay_reg_values - Computed io_reg configuration values (see TRM)
+ * @coarse_ref_count:	Coarse reference count
+ * @coarse_delay_count:	Coarse delay count
+ * @fine_ref_count:	Fine reference count
+ * @fine_delay_count:	Fine Delay count
+ * @ref_clk_period:	Reference Clock period
+ * @cdpe:		Coarse delay parameter
+ * @fdpe:		Fine delay parameter
+ */
+struct ti_iodelay_reg_values {
+	u16 coarse_ref_count;
+	u16 coarse_delay_count;
+
+	u16 fine_ref_count;
+	u16 fine_delay_count;
+
+	u16 ref_clk_period;
+
+	u32 cdpe;
+	u32 fdpe;
+};
+
+/**
+ * struct ti_iodelay_pin_name - name of the pins
+ * @name: name
+ */
+struct ti_iodelay_pin_name {
+	char name[IODELAY_REG_NAME_LEN];
+};
+
+/**
+ * struct ti_iodelay_pingroup - Structure that describes one group
+ * @np:		Node pointer (device tree)
+ * @name:	Name of the group
+ * @map:	pinctrl map allocated for the group
+ * @vals:	configuration values allocated for the group (from dt)
+ * @nvals:	number of configuration values allocated
+ * @config:	pinconf "Config" - currently a dummy value
+ * @node:	list node to next group
+ */
+struct ti_iodelay_pingroup {
+	struct device_node *np;
+	const char *name;
+	struct pinctrl_map *map;
+	struct ti_iodelay_conf_vals *vals;
+	int nvals;
+	unsigned long config;
+	struct list_head node;
+};
+
+/**
+ * struct ti_iodelay_device - Represents information for a IOdelay instance
+ * @dev: device pointer
+ * @reg_base: Remapped virtual address
+ * @regmap: Regmap for this IOdelay instance
+ * @pctl: Pinctrl device
+ * @desc: pinctrl descriptor for pctl
+ * @pa: pinctrl pin wise description
+ * @names: names of the pins
+ * @groups: list of pinconf groups for iodelay instance
+ * @ngroups: number of groups in the list
+ * @mutex: mutex to protect group list modification
+ * @reg_data: Register definition data for the IODelay instance
+ * @reg_init_conf_values: Initial configuration values.
+ */
+struct ti_iodelay_device {
+	struct device *dev;
+	void __iomem *reg_base;
+	struct regmap *regmap;
+
+	struct pinctrl_dev *pctl;
+	struct pinctrl_desc desc;
+	struct pinctrl_pin_desc *pa;
+	struct ti_iodelay_pin_name *names;
+
+	struct list_head groups;
+	int ngroups;
+	struct mutex mutex; /* list protection */
+
+	const struct ti_iodelay_reg_data *reg_data;
+	struct ti_iodelay_reg_values reg_init_conf_values;
+};
+
+/*--- IOdelay configuration stuff ----*/
+
+/**
+ * ti_iodelay_extract() - extract bits for a field
+ * @val:	register value
+ * @mask:	Mask
+ *
+ * Return: extracted value which is appropriately shifted
+ */
+static inline u32 ti_iodelay_extract(u32 val, u32 mask)
+{
+	return (val & mask) >> __ffs(mask);
+}
+
+/**
+ * ti_iodelay_compute_dpe() - Compute equation for delay parameter
+ * @period:	Period to use
+ * @ref:	Reference Count
+ * @delay:	Delay count
+ * @delay_m:	Delay multiplier
+ *
+ * Return: Computed delay parameter
+ */
+static inline u32 ti_iodelay_compute_dpe(u16 period, u16 ref, u16 delay,
+					 u16 delay_m)
+{
+	u64 m, d;
+
+	/* Handle overflow conditions */
+	m = 10 * (u64)period * (u64)ref;
+	d = 2 * (u64)delay * (u64)delay_m;
+
+	/* Truncate result back to 32 bits */
+	return div64_u64(m, d);
+}
+
+/**
+ * ti_iodelay_pinconf_set() - Configure the pin configuration
+ * @iod:	IODelay device
+ * @val:	Configuration value
+ *
+ * Update the configuration register as per TRM and lockup once done.
+ * *IMPORTANT NOTE* SoC TRM does recommend doing iodelay programmation only
+ * while in Isolation. But, then, isolation also implies that every pin
+ * on the SoC(including DDR) will be isolated out. The only benefit being
+ * a glitchless configuration, However, the intent of this driver is purely
+ * to support a "glitchy" configuration where applicable.
+ *
+ * Return: 0 in case of success, else appropriate error value
+ */
+static int ti_iodelay_pinconf_set(struct ti_iodelay_device *iod,
+				  struct ti_iodelay_conf_vals *val)
+{
+	const struct ti_iodelay_reg_data *reg = iod->reg_data;
+	struct ti_iodelay_reg_values *ival = &iod->reg_init_conf_values;
+	struct device *dev = iod->dev;
+	u32 g_delay_coarse, g_delay_fine;
+	u32 a_delay_coarse, a_delay_fine;
+	u32 c_elements, f_elements;
+	u32 total_delay;
+	u32 reg_mask, reg_val, tmp_val;
+	int r;
+
+	/* NOTE: Truncation is expected in all division below */
+	g_delay_coarse = val->g_delay / 920;
+	g_delay_fine = ((val->g_delay % 920) * 10) / 60;
+
+	a_delay_coarse = val->a_delay / ival->cdpe;
+	a_delay_fine = ((val->a_delay % ival->cdpe) * 10) / ival->fdpe;
+
+	c_elements = g_delay_coarse + a_delay_coarse;
+	f_elements = (g_delay_fine + a_delay_fine) / 10;
+
+	if (f_elements > 22) {
+		total_delay = c_elements * ival->cdpe + f_elements * ival->fdpe;
+		c_elements = total_delay / ival->cdpe;
+		f_elements = (total_delay % ival->cdpe) / ival->fdpe;
+	}
+
+	reg_mask = reg->signature_mask;
+	reg_val = reg->signature_value << __ffs(reg->signature_mask);
+
+	reg_mask |= reg->binary_data_coarse_mask;
+	tmp_val = c_elements << __ffs(reg->binary_data_coarse_mask);
+	if (tmp_val & ~reg->binary_data_coarse_mask) {
+		dev_err(dev, "Masking overflow of coarse elements %08x\n",
+			tmp_val);
+		tmp_val &= reg->binary_data_coarse_mask;
+	}
+	reg_val |= tmp_val;
+
+	reg_mask |= reg->binary_data_fine_mask;
+	tmp_val = f_elements << __ffs(reg->binary_data_fine_mask);
+	if (tmp_val & ~reg->binary_data_fine_mask) {
+		dev_err(dev, "Masking overflow of fine elements %08x\n",
+			tmp_val);
+		tmp_val &= reg->binary_data_fine_mask;
+	}
+	reg_val |= tmp_val;
+
+	/* Write with lock value - we DONOT want h/w updates */
+	reg_mask |= reg->lock_mask;
+	reg_val |= reg->lock_val << __ffs(reg->lock_mask);
+	r = regmap_update_bits(iod->regmap, val->offset, reg_mask, reg_val);
+
+	dev_dbg(dev, "Set reg 0x%x Delay(a=%d g=%d), Elements(C=%d F=%d)0x%x\n",
+		val->offset, val->a_delay, val->g_delay, c_elements,
+		f_elements, reg_val);
+
+	return r;
+}
+
+/**
+ * ti_iodelay_pinconf_init_dev() - Initialize IODelay device
+ * @iod:	IODelay device
+ *
+ * Unlocks the IODelay region, computes the common parameters
+ *
+ * Return: 0 in case of success, else appropriate error value
+ */
+static int ti_iodelay_pinconf_init_dev(struct ti_iodelay_device *iod)
+{
+	const struct ti_iodelay_reg_data *reg = iod->reg_data;
+	struct device *dev = iod->dev;
+	struct ti_iodelay_reg_values *ival = &iod->reg_init_conf_values;
+	u32 val;
+	int r;
+
+	/* unlock the IOdelay region */
+	r = regmap_update_bits(iod->regmap, reg->reg_global_lock_offset,
+			       reg->global_lock_mask, reg->global_unlock_val);
+	if (r)
+		return r;
+
+	/* Read up Recalibration sequence done by bootloader */
+	r = regmap_read(iod->regmap, reg->reg_refclk_offset, &val);
+	if (r)
+		return r;
+	ival->ref_clk_period = ti_iodelay_extract(val, reg->refclk_period_mask);
+	dev_dbg(dev, "refclk_period=0x%04x\n", ival->ref_clk_period);
+
+	r = regmap_read(iod->regmap, reg->reg_coarse_offset, &val);
+	if (r)
+		return r;
+	ival->coarse_ref_count =
+	    ti_iodelay_extract(val, reg->coarse_ref_count_mask);
+	ival->coarse_delay_count =
+	    ti_iodelay_extract(val, reg->coarse_delay_count_mask);
+	if (!ival->coarse_delay_count) {
+		dev_err(dev, "Invalid Coarse delay count (0) (reg=0x%08x)\n",
+			val);
+		return -EINVAL;
+	}
+	ival->cdpe = ti_iodelay_compute_dpe(ival->ref_clk_period,
+					    ival->coarse_ref_count,
+					    ival->coarse_delay_count, 88);
+	if (!ival->cdpe) {
+		dev_err(dev, "Invalid cdpe computed params = %d %d %d\n",
+			ival->ref_clk_period, ival->coarse_ref_count,
+			ival->coarse_delay_count);
+		return -EINVAL;
+	}
+	dev_dbg(iod->dev, "coarse: ref=0x%04x delay=0x%04x cdpe=0x%08x\n",
+		ival->coarse_ref_count, ival->coarse_delay_count, ival->cdpe);
+
+	r = regmap_read(iod->regmap, reg->reg_fine_offset, &val);
+	if (r)
+		return r;
+	ival->fine_ref_count =
+	    ti_iodelay_extract(val, reg->fine_ref_count_mask);
+	ival->fine_delay_count =
+	    ti_iodelay_extract(val, reg->fine_delay_count_mask);
+	if (!ival->fine_delay_count) {
+		dev_err(dev, "Invalid Fine delay count (0) (reg=0x%08x)\n",
+			val);
+		return -EINVAL;
+	}
+	ival->fdpe = ti_iodelay_compute_dpe(ival->ref_clk_period,
+					    ival->fine_ref_count,
+					    ival->fine_delay_count, 264);
+	if (!ival->fdpe) {
+		dev_err(dev, "Invalid fdpe(0) computed params = %d %d %d\n",
+			ival->ref_clk_period, ival->fine_ref_count,
+			ival->fine_delay_count);
+		return -EINVAL;
+	}
+	dev_dbg(iod->dev, "fine: ref=0x%04x delay=0x%04x fdpe=0x%08x\n",
+		ival->fine_ref_count, ival->fine_delay_count, ival->fdpe);
+
+	return 0;
+}
+
+/**
+ * ti_iodelay_pinconf_deinit_dev() - deinit the IOdelay device
+ * @iod:	IODelay device
+ *
+ * Deinitialize the IODelay device (basically just lock the region back up.
+ */
+static void ti_iodelay_pinconf_deinit_dev(struct ti_iodelay_device *iod)
+{
+	const struct ti_iodelay_reg_data *reg = iod->reg_data;
+
+	/* lock the IOdelay region back again */
+	regmap_update_bits(iod->regmap, reg->reg_global_lock_offset,
+			   reg->global_lock_mask, reg->global_lock_val);
+}
+
+/*--- Pinctrl/pinconf framework stuff ----*/
+
+/**
+ * ti_iodelay_get_group() - Find the group mapped by a group selector
+ * @iod:	IODelay device
+ * @gselector:	Group Selector
+ *
+ * Return: Corresponding group representing group selector in list of groups
+ * managed in IOdelay device OR NULL if not found.
+ */
+static struct ti_iodelay_pingroup *ti_iodelay_get_group(struct ti_iodelay_device
+							*iod,
+							unsigned gselector)
+{
+	struct ti_iodelay_pingroup *group;
+	int gid = 0;
+
+	list_for_each_entry(group, &iod->groups, node) {
+		if (gid == gselector)
+			return group;
+		gid++;
+	}
+
+	dev_err(iod->dev, "%s could not find pingroup %i\n", __func__,
+		gselector);
+	return NULL;
+}
+
+/**
+ * ti_iodelay_dt_node_to_map() - Map a device tree node to appropriate group
+ * @pctldev:	pinctrl device representing IODelay device
+ * @np:		Node Pointer (device tree)
+ * @map:	Pinctrl Map returned back to pinctrl framework
+ * @num_maps:	Number of maps (1)
+ *
+ * Maps the device tree description into a group of configuration parameters
+ * for IOdelay block entry.
+ *
+ * Return: 0 in case of success, else appropriate error value
+ */
+static int ti_iodelay_dt_node_to_map(struct pinctrl_dev *pctldev,
+				     struct device_node *np,
+				     struct pinctrl_map **map,
+				     unsigned *num_maps)
+{
+	struct ti_iodelay_device *iod;
+	struct device *dev;
+	/* const char **pgnames; */
+	int ret = 0;
+	const __be32 *mux;
+	struct ti_iodelay_conf_vals *vals;
+	struct ti_iodelay_pingroup *group;
+	int size, index, idx, rows;
+	u32 offset, val;
+
+	iod = pinctrl_dev_get_drvdata(pctldev);
+	if (!iod)
+		return -EINVAL;
+	dev = iod->dev;
+
+	*map = devm_kzalloc(dev, sizeof(**map), GFP_KERNEL);
+	if (!*map)
+		return -ENOMEM;
+	*num_maps = 0;
+
+	group = devm_kzalloc(dev, sizeof(*group), GFP_KERNEL);
+	if (!group) {
+		ret = -ENOMEM;
+		goto free_map;
+	}
+
+	mux = of_get_property(np, IODELAY_MUX_PINS_NAME, &size);
+	if ((!mux) || (size < sizeof(*mux) * 2)) {
+		dev_err(dev, "bad data for mux %s\n", np->name);
+		ret = -EINVAL;
+		goto free_group;
+	}
+
+	size /= sizeof(*mux);	/* Number of elements in array */
+	rows = size / 2;
+
+	vals = devm_kzalloc(dev, sizeof(*vals) * rows, GFP_KERNEL);
+	if (!vals) {
+		ret = -ENOMEM;
+		goto free_group;
+	}
+
+	index = 0;
+	idx = 0;
+	while (index < size) {
+		offset = be32_to_cpup(mux + index++);
+		val = be32_to_cpup(mux + index++);
+		vals[idx].offset = offset;
+		vals[idx].a_delay = val & 0xFFFF;
+		vals[idx].g_delay = (val & 0xFFFF0000) >> 16;
+		if (offset > iod->reg_data->regmap_config->max_register) {
+			dev_err(dev, "Invalid offset for %s 0x%x\n",
+				np->name, offset);
+			break;
+		}
+		dev_dbg(dev, "%s offset=%x a_delay = %d g_delay = %d\n",
+			np->name, vals[idx].offset, vals[idx].a_delay,
+			vals[idx].g_delay);
+		idx++;
+	}
+
+	group->name = np->name;
+	group->np = np;
+	group->vals = vals;
+	group->nvals = idx;
+	group->config = PIN_CONFIG_END;
+	group->map = *map;
+
+	/* Add to group list */
+	mutex_lock(&iod->mutex);
+	list_add_tail(&group->node, &iod->groups);
+	iod->ngroups++;
+	mutex_unlock(&iod->mutex);
+
+	(*map)->type = PIN_MAP_TYPE_CONFIGS_GROUP;
+	(*map)->data.configs.group_or_pin = np->name;
+	(*map)->data.configs.configs = &group->config;
+	(*map)->data.configs.num_configs = 1;
+	*num_maps = 1;
+
+	return 0;
+
+free_group:
+	devm_kfree(dev, group);
+free_map:
+	devm_kfree(dev, *map);
+	return ret;
+}
+
+/**
+ * ti_iodelay_dt_free_map() - Free map and resource alloted as per the map
+ * @pctldev:	pinctrl device representing IODelay device
+ * @map:	Map allocated by ti_iodelay_dt_node_to_map
+ * @num_maps:	Num maps (1)
+ *
+ * Removes the group associated with the map and frees all resources allocated
+ * for the group.
+ */
+static void ti_iodelay_dt_free_map(struct pinctrl_dev *pctldev,
+				   struct pinctrl_map *map, unsigned num_maps)
+{
+	struct ti_iodelay_device *iod;
+	struct device *dev;
+	struct ti_iodelay_pingroup *group;
+	bool found = false;
+
+	if (!map)
+		return;
+
+	iod = pinctrl_dev_get_drvdata(pctldev);
+	if (!iod)
+		return;
+	dev = iod->dev;
+
+	mutex_lock(&iod->mutex);
+	list_for_each_entry(group, &iod->groups, node) {
+		if (group->map == map) {
+			found = true;
+			list_del(&group->node);
+			iod->ngroups--;
+			break;
+		}
+	}
+	mutex_unlock(&iod->mutex);
+
+	/* If some freaky pinconf framework bug... */
+	if (!found)
+		return;
+
+	devm_kfree(dev, group->vals);
+	devm_kfree(dev, group);
+	devm_kfree(dev, map);
+}
+
+/**
+ * ti_iodelay_pinctrl_get_groups_count() - Get number of groups registered
+ * @pctldev:	pinctrl device representing IODelay device
+ *
+ * Return: number of groups mapped on the IODelay
+ */
+static int ti_iodelay_pinctrl_get_groups_count(struct pinctrl_dev *pctldev)
+{
+	struct ti_iodelay_device *iod;
+	struct device *dev;
+
+	iod = pinctrl_dev_get_drvdata(pctldev);
+	dev = iod->dev;
+
+	return iod->ngroups;
+}
+
+/**
+ * ti_iodelay_pinctrl_get_group_name() - Get the group name
+ * @pctldev:	pinctrl device representing IODelay device
+ * @gselector:	group selector
+ *
+ * Return: name of the Group given a valid gselector, else NULL.
+ */
+static const char *ti_iodelay_pinctrl_get_group_name(struct pinctrl_dev
+						     *pctldev,
+						     unsigned gselector)
+{
+	struct ti_iodelay_device *iod;
+	struct device *dev;
+	struct ti_iodelay_pingroup *group;
+
+	iod = pinctrl_dev_get_drvdata(pctldev);
+	dev = iod->dev;
+
+	group = ti_iodelay_get_group(iod, gselector);
+	if (!group)
+		return NULL;
+
+	return group->name;
+}
+
+/**
+ * ti_iodelay_pinctrl_get_group_pins() - get group pins
+ * @pctldev:	pinctrl device representing IODelay device
+ * @gselector: Group selector
+ * @pins:	pointer to the pins
+ * @npins:	number of pins
+ *
+ * Dummy implementation since we do not track pins, we track configurations
+ * Forced by pinctrl's pinctrl_check_ops()
+ *
+ * Return: -EINVAL
+ */
+static int ti_iodelay_pinctrl_get_group_pins(struct pinctrl_dev *pctldev,
+					     unsigned gselector,
+					     const unsigned **pins,
+					     unsigned *npins)
+{
+	/* Dummy implementation - we dont do pin mux */
+	return -EINVAL;
+}
+
+/**
+ * ti_iodelay_pinconf_group_get() - Get the group configuration
+ * @pctldev:	pinctrl device representing IODelay device
+ * @gselector:	Group selector
+ * @config:	configuration returned
+ *
+ * Return: The configuration if the group is valid, else returns -EINVAL
+ */
+static int ti_iodelay_pinconf_group_get(struct pinctrl_dev *pctldev,
+					unsigned gselector,
+					unsigned long *config)
+{
+	struct ti_iodelay_device *iod;
+	struct device *dev;
+	struct ti_iodelay_pingroup *group;
+
+	iod = pinctrl_dev_get_drvdata(pctldev);
+	dev = iod->dev;
+	group = ti_iodelay_get_group(iod, gselector);
+
+	if (!group)
+		return -EINVAL;
+
+	*config = group->config;
+	return 0;
+}
+
+/**
+ * ti_iodelay_pinconf_group_set() - Configure the groups of pins
+ * @pctldev:	pinctrl device representing IODelay device
+ * @gselector:	Group selector
+ * @configs:	Configurations
+ * @num_configs: Number of configurations
+ *
+ * Return: 0 if all went fine, else appropriate error value.
+ */
+static int ti_iodelay_pinconf_group_set(struct pinctrl_dev *pctldev,
+					unsigned gselector,
+					unsigned long *configs,
+					unsigned num_configs)
+{
+	struct ti_iodelay_device *iod;
+	struct device *dev;
+	struct ti_iodelay_pingroup *group;
+	int i;
+
+	iod = pinctrl_dev_get_drvdata(pctldev);
+	dev = iod->dev;
+	group = ti_iodelay_get_group(iod, gselector);
+
+	if (num_configs != 1) {
+		dev_err(dev, "Unsupported number of configurations %d\n",
+			num_configs);
+		return -EINVAL;
+	}
+
+	if (*configs != PIN_CONFIG_END) {
+		dev_err(dev, "Unsupported configuration\n");
+		return -EINVAL;
+	}
+
+	for (i = 0; i < group->nvals; i++) {
+		if (ti_iodelay_pinconf_set(iod, &group->vals[i]))
+			return -ENOTSUPP;
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_DEBUG_FS
+/**
+ * ti_iodelay_pinconf_group_dbg_show() - show the group information
+ * @pctldev:	Show the group information
+ * @s:	Sequence file
+ * @gselector:	group selector
+ *
+ * Provide the configuration information of the selected group
+ */
+static void ti_iodelay_pinconf_group_dbg_show(struct pinctrl_dev *pctldev,
+					      struct seq_file *s,
+					      unsigned gselector)
+{
+	struct ti_iodelay_device *iod;
+	struct device *dev;
+	struct ti_iodelay_pingroup *group;
+	int i;
+
+	iod = pinctrl_dev_get_drvdata(pctldev);
+	dev = iod->dev;
+	group = ti_iodelay_get_group(iod, gselector);
+	if (!group)
+		return;
+
+	for (i = 0; i < group->nvals; i++) {
+		struct ti_iodelay_conf_vals *val;
+		u32 reg = 0;
+
+		val = &group->vals[i];
+		regmap_read(iod->regmap, val->offset, &reg),
+		    seq_printf(s, "\n\t0x%08x = 0x%08x (%3d, %3d)",
+			       val->offset, reg, val->a_delay, val->g_delay);
+	}
+}
+#endif
+
+static struct pinctrl_ops ti_iodelay_pinctrl_ops = {
+	.dt_node_to_map = ti_iodelay_dt_node_to_map,
+	.dt_free_map = ti_iodelay_dt_free_map,
+	.get_groups_count = ti_iodelay_pinctrl_get_groups_count,
+	.get_group_name = ti_iodelay_pinctrl_get_group_name,
+	.get_group_pins = ti_iodelay_pinctrl_get_group_pins,
+};
+
+static struct pinconf_ops ti_iodelay_pinctrl_pinconf_ops = {
+	.pin_config_group_get = ti_iodelay_pinconf_group_get,
+	.pin_config_group_set = ti_iodelay_pinconf_group_set,
+#ifdef CONFIG_DEBUG_FS
+	.pin_config_group_dbg_show = ti_iodelay_pinconf_group_dbg_show,
+#endif
+};
+
+/**
+ * ti_iodelay_alloc_pins() - Allocate structures needed for pins for IOdelay
+ * @dev:	device pointer
+ * @iod:	IODelay device
+ * @base_phy:	Base Physical Address
+ *
+ * Return: 0 if all went fine, else appropriate error value.
+ */
+static int ti_iodelay_alloc_pins(struct device *dev,
+				 struct ti_iodelay_device *iod, u32 base_phy)
+{
+	const struct ti_iodelay_reg_data *r = iod->reg_data;
+	struct pinctrl_pin_desc *pin;
+	struct ti_iodelay_pin_name *pn;
+	u32 phy_reg;
+	int nr_pins, i;
+
+	nr_pins = (r->regmap_config->max_register - r->reg_start_offset) / 4;
+
+	dev_dbg(dev, "Allocating %i pins\n", nr_pins);
+
+	iod->pa = devm_kzalloc(dev, sizeof(*iod->pa) * nr_pins, GFP_KERNEL);
+	if (!iod->pa)
+		return -ENOMEM;
+
+	iod->names =
+	    devm_kzalloc(dev, sizeof(struct ti_iodelay_pin_name) * nr_pins,
+			 GFP_KERNEL);
+	if (!iod->names)
+		return -ENOMEM;
+
+	iod->desc.pins = iod->pa;
+	iod->desc.npins = nr_pins;
+
+	phy_reg = r->reg_start_offset + base_phy;
+	pn = iod->names;
+	for (i = 0; i < nr_pins; i++, pn++, phy_reg += 4) {
+		pin = &iod->pa[i];
+		sprintf(pn->name, "%x.%d", phy_reg, i);
+		pin->number = i;
+		pin->name = pn->name;
+	}
+
+	return 0;
+}
+
+/**
+ * ti_iodelay_probe() - Standard probe
+ * @pdev:	platform device
+ *
+ * Return: 0 if all went fine, else appropriate error value.
+ */
+static int ti_iodelay_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = of_node_get(dev->of_node);
+	const struct of_device_id *match;
+	struct resource *res;
+	struct ti_iodelay_device *iod;
+	int ret = 0;
+
+	if (!np) {
+		ret = -EINVAL;
+		dev_err(dev, "No OF node\n");
+		goto exit_out;
+	}
+
+	match = of_match_device(ti_iodelay_of_match, dev);
+	if (!match) {
+		ret = -EINVAL;
+		dev_err(dev, "No DATA match\n");
+		goto exit_out;
+	}
+
+	iod = devm_kzalloc(dev, sizeof(*iod), GFP_KERNEL);
+	if (!iod) {
+		ret = -ENOMEM;
+		goto exit_out;
+	}
+	iod->dev = dev;
+	iod->reg_data = match->data;
+
+	/* So far We can assume there is only 1 bank of registers */
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(dev, "Missing MEM resource\n");
+		ret = -ENODEV;
+		goto exit_out;
+	}
+
+	iod->reg_base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(iod->reg_base)) {
+		ret = PTR_ERR(iod->reg_base);
+		goto exit_out;
+	}
+
+	iod->regmap = devm_regmap_init_mmio(dev, iod->reg_base,
+					    iod->reg_data->regmap_config);
+	if (IS_ERR(iod->regmap)) {
+		dev_err(dev, "Regmap MMIO init failed.\n");
+		ret = PTR_ERR(iod->regmap);
+		goto exit_out;
+	}
+
+	if (ti_iodelay_pinconf_init_dev(iod))
+		goto exit_out;
+
+	ret = ti_iodelay_alloc_pins(dev, iod, res->start);
+	if (ret)
+		goto exit_out;
+
+	INIT_LIST_HEAD(&iod->groups);
+	mutex_init(&iod->mutex);
+
+	iod->desc.pctlops = &ti_iodelay_pinctrl_ops;
+	/* no pinmux ops - we are pinconf */
+	iod->desc.confops = &ti_iodelay_pinctrl_pinconf_ops;
+	iod->desc.name = dev_name(dev);
+	iod->desc.owner = THIS_MODULE;
+
+	iod->pctl = pinctrl_register(&iod->desc, dev, iod);
+	if (!iod->pctl) {
+		dev_err(dev, "Failed to register pinctrl\n");
+		ret = -ENODEV;
+		goto exit_out;
+	}
+
+	platform_set_drvdata(pdev, iod);
+
+exit_out:
+	of_node_put(np);
+	return ret;
+}
+
+/**
+ * ti_iodelay_remove() - standard remove
+ * @pdev:	platform device
+ *
+ * Return: 0 if all went fine, else appropriate error value.
+ */
+static int ti_iodelay_remove(struct platform_device *pdev)
+{
+	struct ti_iodelay_device *iod = platform_get_drvdata(pdev);
+
+	if (!iod)
+		return 0;
+	if (iod->pctl)
+		pinctrl_unregister(iod->pctl);
+
+	ti_iodelay_pinconf_deinit_dev(iod);
+
+	/* Expect other allocations to be freed by devm */
+
+	return 0;
+}
+
+static struct regmap_config dra7_iodelay_regmap_config = {
+	.reg_bits = 32,
+	.reg_stride = 4,
+	.val_bits = 32,
+	.max_register = 0xD1C,
+};
+
+static struct ti_iodelay_reg_data dra7_iodelay_data = {
+	.signature_mask = 0x0003F000,
+	.signature_value = 0x29,
+	.lock_mask = 0x00000400,
+	.lock_val = 1,
+	.unlock_val = 0,
+	.binary_data_coarse_mask = 0x000003E0,
+	.binary_data_fine_mask = 0x0000001F,
+
+	.reg_refclk_offset = 0x14,
+	.refclk_period_mask = 0xFFFF,
+
+	.reg_coarse_offset = 0x18,
+	.coarse_delay_count_mask = 0xFFFF0000,
+	.coarse_ref_count_mask = 0x0000FFFF,
+
+	.reg_fine_offset = 0x1C,
+	.fine_delay_count_mask = 0xFFFF0000,
+	.fine_ref_count_mask = 0x0000FFFF,
+
+	.reg_global_lock_offset = 0x2C,
+	.global_lock_mask = 0x0000FFFF,
+	.global_unlock_val = 0x0000AAAA,
+	.global_lock_val = 0x0000AAAB,
+
+	.reg_start_offset = 0x30,
+	.regmap_config = &dra7_iodelay_regmap_config,
+};
+
+static const struct of_device_id ti_iodelay_of_match[] = {
+	{.compatible = "ti,dra7-iodelay", .data = &dra7_iodelay_data},
+	{ /* Hopefully no more.. */ },
+};
+MODULE_DEVICE_TABLE(of, ti_iodelay_of_match);
+
+static struct platform_driver ti_iodelay_driver = {
+	.probe = ti_iodelay_probe,
+	.remove = ti_iodelay_remove,
+	.driver = {
+		   .owner = THIS_MODULE,
+		   .name = DRIVER_NAME,
+		   .of_match_table = ti_iodelay_of_match,
+		   },
+};
+module_platform_driver(ti_iodelay_driver);
+
+MODULE_AUTHOR("Texas Instruments, Inc.");
+MODULE_DESCRIPTION("Pinconf driver for TI's IO Delay module");
+MODULE_LICENSE("GPL v2");
diff --git a/include/dt-bindings/pinctrl/dra.h b/include/dt-bindings/pinctrl/dra.h
index 7448edff4723..0a26495c4df5 100644
--- a/include/dt-bindings/pinctrl/dra.h
+++ b/include/dt-bindings/pinctrl/dra.h
@@ -30,6 +30,8 @@
 #define MUX_MODE14	0xe
 #define MUX_MODE15	0xf
 
+#define MANUAL_MODE		MODE_SELECT
+
 #define PULL_ENA		(0 << 16)
 #define PULL_DIS		(1 << 16)
 #define PULL_UP			(1 << 17)
@@ -47,5 +49,9 @@
 #define PIN_INPUT_PULLUP	(PULL_ENA | INPUT_EN | PULL_UP)
 #define PIN_INPUT_PULLDOWN	(PULL_ENA | INPUT_EN)
 
+/* DRA7 IODELAY configuration parameters */
+#define A_DELAY(val)		((val) & 0xFFFF)
+#define G_DELAY(val)		(((val) & 0xFFFF) << 16)
+
 #endif
 
-- 
1.7.9.5

[PATCH 2/2] pinctrl: Introduce TI IOdelay configuration driver

[Nishanth Menon]

SoC family such as DRA7 family of processors have, in addition
to the regular muxing of pins (as done by pinctrl-single), an
additional hardware module called IODelay which is also expected to be
configured. This "IODelay" module has it's own register space that is
independent of the control module.

It is advocated strongly in TI's official documentation considering
the existing design of the DRA7 family of processors during mux or
IODelay reconfiguration, there is a potential for a significant glitch
which may cause functional impairment to certain hardware. It is
hence recommended to do as little of muxing as absolutely necessary
without I/O isolation (which can only be done in initial stages of
bootloader).

NOTE: with the system wide I/O isolation scheme present in DRA7 SoC
family, it is not reasonable to do stop all I/O operations for every
such pad configuration scheme. So, we will let it glitch when used in
this mode.

Even with the above limitation, certain functionality such as MMC has
mandatory need for IODelay reconfiguration requirements, depending on
speed of transfer. In these cases, with careful examination of usecase
involved, the expected glitch can be controlled such that it does not
impact functionality.

In short, IODelay module support as a padconf driver being introduced
here is not expected to do SoC wide I/O Isolation and is meant for
a limited subset of IODelay configuration requirements that need to
be dynamic and whose glitchy behavior will not cause functionality
failure for that interface.

Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
---
 drivers/pinctrl/Kconfig              |   11 +
 drivers/pinctrl/Makefile             |    1 +
 drivers/pinctrl/pinctrl-ti-iodelay.c |  963 ++++++++++++++++++++++++++++++++++
 include/dt-bindings/pinctrl/dra.h    |    6 +
 4 files changed, 981 insertions(+)
 create mode 100644 drivers/pinctrl/pinctrl-ti-iodelay.c

diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig
index ee9f44ad7f02..8e463d75fbb2 100644
--- a/drivers/pinctrl/Kconfig
+++ b/drivers/pinctrl/Kconfig
@@ -160,6 +160,17 @@ config PINCTRL_TEGRA_XUSB
 	select PINCONF
 	select PINMUX
 
+config PINCTRL_TI_IODELAY
+	bool "TI IODelay Module pinconf driver"
+	depends on OF
+	select PINCONF
+	select GENERIC_PINCONF
+	select REGMAP_MMIO
+	help
+	  Say Y here to support Texas Instruments' IODelay pinconf driver.
+	  IODelay module is used for the DRA7 SoC family. This driver is in
+	  addition to PINCTRL_SINGLE which controls the mux.
+
 config PINCTRL_TZ1090
 	bool "Toumaz Xenif TZ1090 pin control driver"
 	depends on SOC_TZ1090
diff --git a/drivers/pinctrl/Makefile b/drivers/pinctrl/Makefile
index 0475206dd600..e441cd71aedf 100644
--- a/drivers/pinctrl/Makefile
+++ b/drivers/pinctrl/Makefile
@@ -28,6 +28,7 @@ obj-$(CONFIG_PINCTRL_TEGRA30)	+= pinctrl-tegra30.o
 obj-$(CONFIG_PINCTRL_TEGRA114)	+= pinctrl-tegra114.o
 obj-$(CONFIG_PINCTRL_TEGRA124)	+= pinctrl-tegra124.o
 obj-$(CONFIG_PINCTRL_TEGRA_XUSB)	+= pinctrl-tegra-xusb.o
+obj-$(CONFIG_PINCTRL_TI_IODELAY)	+= pinctrl-ti-iodelay.o
 obj-$(CONFIG_PINCTRL_TZ1090)	+= pinctrl-tz1090.o
 obj-$(CONFIG_PINCTRL_TZ1090_PDC)	+= pinctrl-tz1090-pdc.o
 obj-$(CONFIG_PINCTRL_U300)	+= pinctrl-u300.o
diff --git a/drivers/pinctrl/pinctrl-ti-iodelay.c b/drivers/pinctrl/pinctrl-ti-iodelay.c
new file mode 100644
index 000000000000..e4c6e25a781c
--- /dev/null
+++ b/drivers/pinctrl/pinctrl-ti-iodelay.c
@@ -0,0 +1,963 @@
+/*
+ * Support for configuration of IO Delay module found on Texas Instruments SoCs
+ * such as DRA7
+ *
+ * Copyright (C) 2015 Texas Instruments, Inc.
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/of.h>
+#include <linux/pinctrl/pinconf-generic.h>
+#include <linux/pinctrl/pinconf.h>
+#include <linux/pinctrl/pinctrl.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+#define IODELAY_REG_NAME_LEN		((sizeof(u32) * 2) + 3)
+#define DRIVER_NAME			"ti-io-delay"
+/* Should I change this? Abuse? */
+#define IODELAY_MUX_PINS_NAME		"pinctrl-single,pins"
+
+/* Device tree match, populated later */
+static const struct of_device_id ti_iodelay_of_match[];
+
+/**
+ * struct ti_iodelay_conf_vals - Description of each configuration parameters.
+ * @offset:	Configuration register offset
+ * @a_delay:	Agnostic Delay (in ps)
+ * @g_delay:	Gnostic Delay (in ps)
+ */
+struct ti_iodelay_conf_vals {
+	u16 offset;
+	u16 a_delay;
+	u16 g_delay;
+};
+
+/**
+ * struct ti_iodelay_reg_data - Describes the registers for the IOdelay instance
+ * @signature_mask:	Conf reg- mask for the signature bits
+ * @signature_value:	Conf reg- signature value to be written (see TRM)
+ * @lock_mask:		Conf reg- mask for the lock bits
+ * @lock_val:		Conf reg- lock value for the lock bits (see TRM)
+ * @unlock_val:		Conf reg- unlock value for the lock bits (see TRM)
+ * @binary_data_coarse_mask: Conf reg- coarse mask (see TRM)
+ * @binary_data_fine_mask: Conf reg- fine mask (see TRM)
+ * @reg_refclk_offset:	Refclk register offset
+ * @refclk_period_mask:	Refclk mask
+ * @reg_coarse_offset:	Coarse register configuration offset
+ * @coarse_delay_count_mask: Coarse delay count mask
+ * @coarse_ref_count_mask: Coarse ref count mask
+ * @reg_fine_offset:	Fine register configuration offset
+ * @fine_delay_count_mask: Fine delay count mask
+ * @fine_ref_count_mask: Fine  ref count mask
+ * @reg_global_lock_offset: Global(for the IOdelay module) lock register offset
+ * @global_lock_mask:	Lock mask
+ * @global_unlock_val:	unlock value
+ * @global_lock_val:	lock value
+ * @reg_start_offset:	Where does the configuration registers start?
+ * @regmap_config:	Regmap configuration for the IODelay region
+ */
+struct ti_iodelay_reg_data {
+	u32 signature_mask;
+	u32 signature_value;
+	u32 lock_mask;
+	u32 lock_val;
+	u32 unlock_val;
+	u32 binary_data_coarse_mask;
+	u32 binary_data_fine_mask;
+
+	u32 reg_refclk_offset;
+	u32 refclk_period_mask;
+
+	u32 reg_coarse_offset;
+	u32 coarse_delay_count_mask;
+	u32 coarse_ref_count_mask;
+
+	u32 reg_fine_offset;
+	u32 fine_delay_count_mask;
+	u32 fine_ref_count_mask;
+
+	u32 reg_global_lock_offset;
+	u32 global_lock_mask;
+	u32 global_unlock_val;
+	u32 global_lock_val;
+
+	u32 reg_start_offset;
+
+	struct regmap_config *regmap_config;
+};
+
+/**
+ * struct ti_iodelay_reg_values - Computed io_reg configuration values (see TRM)
+ * @coarse_ref_count:	Coarse reference count
+ * @coarse_delay_count:	Coarse delay count
+ * @fine_ref_count:	Fine reference count
+ * @fine_delay_count:	Fine Delay count
+ * @ref_clk_period:	Reference Clock period
+ * @cdpe:		Coarse delay parameter
+ * @fdpe:		Fine delay parameter
+ */
+struct ti_iodelay_reg_values {
+	u16 coarse_ref_count;
+	u16 coarse_delay_count;
+
+	u16 fine_ref_count;
+	u16 fine_delay_count;
+
+	u16 ref_clk_period;
+
+	u32 cdpe;
+	u32 fdpe;
+};
+
+/**
+ * struct ti_iodelay_pin_name - name of the pins
+ * @name: name
+ */
+struct ti_iodelay_pin_name {
+	char name[IODELAY_REG_NAME_LEN];
+};
+
+/**
+ * struct ti_iodelay_pingroup - Structure that describes one group
+ * @np:		Node pointer (device tree)
+ * @name:	Name of the group
+ * @map:	pinctrl map allocated for the group
+ * @vals:	configuration values allocated for the group (from dt)
+ * @nvals:	number of configuration values allocated
+ * @config:	pinconf "Config" - currently a dummy value
+ * @node:	list node to next group
+ */
+struct ti_iodelay_pingroup {
+	struct device_node *np;
+	const char *name;
+	struct pinctrl_map *map;
+	struct ti_iodelay_conf_vals *vals;
+	int nvals;
+	unsigned long config;
+	struct list_head node;
+};
+
+/**
+ * struct ti_iodelay_device - Represents information for a IOdelay instance
+ * @dev: device pointer
+ * @reg_base: Remapped virtual address
+ * @regmap: Regmap for this IOdelay instance
+ * @pctl: Pinctrl device
+ * @desc: pinctrl descriptor for pctl
+ * @pa: pinctrl pin wise description
+ * @names: names of the pins
+ * @groups: list of pinconf groups for iodelay instance
+ * @ngroups: number of groups in the list
+ * @mutex: mutex to protect group list modification
+ * @reg_data: Register definition data for the IODelay instance
+ * @reg_init_conf_values: Initial configuration values.
+ */
+struct ti_iodelay_device {
+	struct device *dev;
+	void __iomem *reg_base;
+	struct regmap *regmap;
+
+	struct pinctrl_dev *pctl;
+	struct pinctrl_desc desc;
+	struct pinctrl_pin_desc *pa;
+	struct ti_iodelay_pin_name *names;
+
+	struct list_head groups;
+	int ngroups;
+	struct mutex mutex; /* list protection */
+
+	const struct ti_iodelay_reg_data *reg_data;
+	struct ti_iodelay_reg_values reg_init_conf_values;
+};
+
+/*--- IOdelay configuration stuff ----*/
+
+/**
+ * ti_iodelay_extract() - extract bits for a field
+ * @val:	register value
+ * @mask:	Mask
+ *
+ * Return: extracted value which is appropriately shifted
+ */
+static inline u32 ti_iodelay_extract(u32 val, u32 mask)
+{
+	return (val & mask) >> __ffs(mask);
+}
+
+/**
+ * ti_iodelay_compute_dpe() - Compute equation for delay parameter
+ * @period:	Period to use
+ * @ref:	Reference Count
+ * @delay:	Delay count
+ * @delay_m:	Delay multiplier
+ *
+ * Return: Computed delay parameter
+ */
+static inline u32 ti_iodelay_compute_dpe(u16 period, u16 ref, u16 delay,
+					 u16 delay_m)
+{
+	u64 m, d;
+
+	/* Handle overflow conditions */
+	m = 10 * (u64)period * (u64)ref;
+	d = 2 * (u64)delay * (u64)delay_m;
+
+	/* Truncate result back to 32 bits */
+	return div64_u64(m, d);
+}
+
+/**
+ * ti_iodelay_pinconf_set() - Configure the pin configuration
+ * @iod:	IODelay device
+ * @val:	Configuration value
+ *
+ * Update the configuration register as per TRM and lockup once done.
+ * *IMPORTANT NOTE* SoC TRM does recommend doing iodelay programmation only
+ * while in Isolation. But, then, isolation also implies that every pin
+ * on the SoC(including DDR) will be isolated out. The only benefit being
+ * a glitchless configuration, However, the intent of this driver is purely
+ * to support a "glitchy" configuration where applicable.
+ *
+ * Return: 0 in case of success, else appropriate error value
+ */
+static int ti_iodelay_pinconf_set(struct ti_iodelay_device *iod,
+				  struct ti_iodelay_conf_vals *val)
+{
+	const struct ti_iodelay_reg_data *reg = iod->reg_data;
+	struct ti_iodelay_reg_values *ival = &iod->reg_init_conf_values;
+	struct device *dev = iod->dev;
+	u32 g_delay_coarse, g_delay_fine;
+	u32 a_delay_coarse, a_delay_fine;
+	u32 c_elements, f_elements;
+	u32 total_delay;
+	u32 reg_mask, reg_val, tmp_val;
+	int r;
+
+	/* NOTE: Truncation is expected in all division below */
+	g_delay_coarse = val->g_delay / 920;
+	g_delay_fine = ((val->g_delay % 920) * 10) / 60;
+
+	a_delay_coarse = val->a_delay / ival->cdpe;
+	a_delay_fine = ((val->a_delay % ival->cdpe) * 10) / ival->fdpe;
+
+	c_elements = g_delay_coarse + a_delay_coarse;
+	f_elements = (g_delay_fine + a_delay_fine) / 10;
+
+	if (f_elements > 22) {
+		total_delay = c_elements * ival->cdpe + f_elements * ival->fdpe;
+		c_elements = total_delay / ival->cdpe;
+		f_elements = (total_delay % ival->cdpe) / ival->fdpe;
+	}
+
+	reg_mask = reg->signature_mask;
+	reg_val = reg->signature_value << __ffs(reg->signature_mask);
+
+	reg_mask |= reg->binary_data_coarse_mask;
+	tmp_val = c_elements << __ffs(reg->binary_data_coarse_mask);
+	if (tmp_val & ~reg->binary_data_coarse_mask) {
+		dev_err(dev, "Masking overflow of coarse elements %08x\n",
+			tmp_val);
+		tmp_val &= reg->binary_data_coarse_mask;
+	}
+	reg_val |= tmp_val;
+
+	reg_mask |= reg->binary_data_fine_mask;
+	tmp_val = f_elements << __ffs(reg->binary_data_fine_mask);
+	if (tmp_val & ~reg->binary_data_fine_mask) {
+		dev_err(dev, "Masking overflow of fine elements %08x\n",
+			tmp_val);
+		tmp_val &= reg->binary_data_fine_mask;
+	}
+	reg_val |= tmp_val;
+
+	/* Write with lock value - we DONOT want h/w updates */
+	reg_mask |= reg->lock_mask;
+	reg_val |= reg->lock_val << __ffs(reg->lock_mask);
+	r = regmap_update_bits(iod->regmap, val->offset, reg_mask, reg_val);
+
+	dev_dbg(dev, "Set reg 0x%x Delay(a=%d g=%d), Elements(C=%d F=%d)0x%x\n",
+		val->offset, val->a_delay, val->g_delay, c_elements,
+		f_elements, reg_val);
+
+	return r;
+}
+
+/**
+ * ti_iodelay_pinconf_init_dev() - Initialize IODelay device
+ * @iod:	IODelay device
+ *
+ * Unlocks the IODelay region, computes the common parameters
+ *
+ * Return: 0 in case of success, else appropriate error value
+ */
+static int ti_iodelay_pinconf_init_dev(struct ti_iodelay_device *iod)
+{
+	const struct ti_iodelay_reg_data *reg = iod->reg_data;
+	struct device *dev = iod->dev;
+	struct ti_iodelay_reg_values *ival = &iod->reg_init_conf_values;
+	u32 val;
+	int r;
+
+	/* unlock the IOdelay region */
+	r = regmap_update_bits(iod->regmap, reg->reg_global_lock_offset,
+			       reg->global_lock_mask, reg->global_unlock_val);
+	if (r)
+		return r;
+
+	/* Read up Recalibration sequence done by bootloader */
+	r = regmap_read(iod->regmap, reg->reg_refclk_offset, &val);
+	if (r)
+		return r;
+	ival->ref_clk_period = ti_iodelay_extract(val, reg->refclk_period_mask);
+	dev_dbg(dev, "refclk_period=0x%04x\n", ival->ref_clk_period);
+
+	r = regmap_read(iod->regmap, reg->reg_coarse_offset, &val);
+	if (r)
+		return r;
+	ival->coarse_ref_count =
+	    ti_iodelay_extract(val, reg->coarse_ref_count_mask);
+	ival->coarse_delay_count =
+	    ti_iodelay_extract(val, reg->coarse_delay_count_mask);
+	if (!ival->coarse_delay_count) {
+		dev_err(dev, "Invalid Coarse delay count (0) (reg=0x%08x)\n",
+			val);
+		return -EINVAL;
+	}
+	ival->cdpe = ti_iodelay_compute_dpe(ival->ref_clk_period,
+					    ival->coarse_ref_count,
+					    ival->coarse_delay_count, 88);
+	if (!ival->cdpe) {
+		dev_err(dev, "Invalid cdpe computed params = %d %d %d\n",
+			ival->ref_clk_period, ival->coarse_ref_count,
+			ival->coarse_delay_count);
+		return -EINVAL;
+	}
+	dev_dbg(iod->dev, "coarse: ref=0x%04x delay=0x%04x cdpe=0x%08x\n",
+		ival->coarse_ref_count, ival->coarse_delay_count, ival->cdpe);
+
+	r = regmap_read(iod->regmap, reg->reg_fine_offset, &val);
+	if (r)
+		return r;
+	ival->fine_ref_count =
+	    ti_iodelay_extract(val, reg->fine_ref_count_mask);
+	ival->fine_delay_count =
+	    ti_iodelay_extract(val, reg->fine_delay_count_mask);
+	if (!ival->fine_delay_count) {
+		dev_err(dev, "Invalid Fine delay count (0) (reg=0x%08x)\n",
+			val);
+		return -EINVAL;
+	}
+	ival->fdpe = ti_iodelay_compute_dpe(ival->ref_clk_period,
+					    ival->fine_ref_count,
+					    ival->fine_delay_count, 264);
+	if (!ival->fdpe) {
+		dev_err(dev, "Invalid fdpe(0) computed params = %d %d %d\n",
+			ival->ref_clk_period, ival->fine_ref_count,
+			ival->fine_delay_count);
+		return -EINVAL;
+	}
+	dev_dbg(iod->dev, "fine: ref=0x%04x delay=0x%04x fdpe=0x%08x\n",
+		ival->fine_ref_count, ival->fine_delay_count, ival->fdpe);
+
+	return 0;
+}
+
+/**
+ * ti_iodelay_pinconf_deinit_dev() - deinit the IOdelay device
+ * @iod:	IODelay device
+ *
+ * Deinitialize the IODelay device (basically just lock the region back up.
+ */
+static void ti_iodelay_pinconf_deinit_dev(struct ti_iodelay_device *iod)
+{
+	const struct ti_iodelay_reg_data *reg = iod->reg_data;
+
+	/* lock the IOdelay region back again */
+	regmap_update_bits(iod->regmap, reg->reg_global_lock_offset,
+			   reg->global_lock_mask, reg->global_lock_val);
+}
+
+/*--- Pinctrl/pinconf framework stuff ----*/
+
+/**
+ * ti_iodelay_get_group() - Find the group mapped by a group selector
+ * @iod:	IODelay device
+ * @gselector:	Group Selector
+ *
+ * Return: Corresponding group representing group selector in list of groups
+ * managed in IOdelay device OR NULL if not found.
+ */
+static struct ti_iodelay_pingroup *ti_iodelay_get_group(struct ti_iodelay_device
+							*iod,
+							unsigned gselector)
+{
+	struct ti_iodelay_pingroup *group;
+	int gid = 0;
+
+	list_for_each_entry(group, &iod->groups, node) {
+		if (gid == gselector)
+			return group;
+		gid++;
+	}
+
+	dev_err(iod->dev, "%s could not find pingroup %i\n", __func__,
+		gselector);
+	return NULL;
+}
+
+/**
+ * ti_iodelay_dt_node_to_map() - Map a device tree node to appropriate group
+ * @pctldev:	pinctrl device representing IODelay device
+ * @np:		Node Pointer (device tree)
+ * @map:	Pinctrl Map returned back to pinctrl framework
+ * @num_maps:	Number of maps (1)
+ *
+ * Maps the device tree description into a group of configuration parameters
+ * for IOdelay block entry.
+ *
+ * Return: 0 in case of success, else appropriate error value
+ */
+static int ti_iodelay_dt_node_to_map(struct pinctrl_dev *pctldev,
+				     struct device_node *np,
+				     struct pinctrl_map **map,
+				     unsigned *num_maps)
+{
+	struct ti_iodelay_device *iod;
+	struct device *dev;
+	/* const char **pgnames; */
+	int ret = 0;
+	const __be32 *mux;
+	struct ti_iodelay_conf_vals *vals;
+	struct ti_iodelay_pingroup *group;
+	int size, index, idx, rows;
+	u32 offset, val;
+
+	iod = pinctrl_dev_get_drvdata(pctldev);
+	if (!iod)
+		return -EINVAL;
+	dev = iod->dev;
+
+	*map = devm_kzalloc(dev, sizeof(**map), GFP_KERNEL);
+	if (!*map)
+		return -ENOMEM;
+	*num_maps = 0;
+
+	group = devm_kzalloc(dev, sizeof(*group), GFP_KERNEL);
+	if (!group) {
+		ret = -ENOMEM;
+		goto free_map;
+	}
+
+	mux = of_get_property(np, IODELAY_MUX_PINS_NAME, &size);
+	if ((!mux) || (size < sizeof(*mux) * 2)) {
+		dev_err(dev, "bad data for mux %s\n", np->name);
+		ret = -EINVAL;
+		goto free_group;
+	}
+
+	size /= sizeof(*mux);	/* Number of elements in array */
+	rows = size / 2;
+
+	vals = devm_kzalloc(dev, sizeof(*vals) * rows, GFP_KERNEL);
+	if (!vals) {
+		ret = -ENOMEM;
+		goto free_group;
+	}
+
+	index = 0;
+	idx = 0;
+	while (index < size) {
+		offset = be32_to_cpup(mux + index++);
+		val = be32_to_cpup(mux + index++);
+		vals[idx].offset = offset;
+		vals[idx].a_delay = val & 0xFFFF;
+		vals[idx].g_delay = (val & 0xFFFF0000) >> 16;
+		if (offset > iod->reg_data->regmap_config->max_register) {
+			dev_err(dev, "Invalid offset for %s 0x%x\n",
+				np->name, offset);
+			break;
+		}
+		dev_dbg(dev, "%s offset=%x a_delay = %d g_delay = %d\n",
+			np->name, vals[idx].offset, vals[idx].a_delay,
+			vals[idx].g_delay);
+		idx++;
+	}
+
+	group->name = np->name;
+	group->np = np;
+	group->vals = vals;
+	group->nvals = idx;
+	group->config = PIN_CONFIG_END;
+	group->map = *map;
+
+	/* Add to group list */
+	mutex_lock(&iod->mutex);
+	list_add_tail(&group->node, &iod->groups);
+	iod->ngroups++;
+	mutex_unlock(&iod->mutex);
+
+	(*map)->type = PIN_MAP_TYPE_CONFIGS_GROUP;
+	(*map)->data.configs.group_or_pin = np->name;
+	(*map)->data.configs.configs = &group->config;
+	(*map)->data.configs.num_configs = 1;
+	*num_maps = 1;
+
+	return 0;
+
+free_group:
+	devm_kfree(dev, group);
+free_map:
+	devm_kfree(dev, *map);
+	return ret;
+}
+
+/**
+ * ti_iodelay_dt_free_map() - Free map and resource alloted as per the map
+ * @pctldev:	pinctrl device representing IODelay device
+ * @map:	Map allocated by ti_iodelay_dt_node_to_map
+ * @num_maps:	Num maps (1)
+ *
+ * Removes the group associated with the map and frees all resources allocated
+ * for the group.
+ */
+static void ti_iodelay_dt_free_map(struct pinctrl_dev *pctldev,
+				   struct pinctrl_map *map, unsigned num_maps)
+{
+	struct ti_iodelay_device *iod;
+	struct device *dev;
+	struct ti_iodelay_pingroup *group;
+	bool found = false;
+
+	if (!map)
+		return;
+
+	iod = pinctrl_dev_get_drvdata(pctldev);
+	if (!iod)
+		return;
+	dev = iod->dev;
+
+	mutex_lock(&iod->mutex);
+	list_for_each_entry(group, &iod->groups, node) {
+		if (group->map == map) {
+			found = true;
+			list_del(&group->node);
+			iod->ngroups--;
+			break;
+		}
+	}
+	mutex_unlock(&iod->mutex);
+
+	/* If some freaky pinconf framework bug... */
+	if (!found)
+		return;
+
+	devm_kfree(dev, group->vals);
+	devm_kfree(dev, group);
+	devm_kfree(dev, map);
+}
+
+/**
+ * ti_iodelay_pinctrl_get_groups_count() - Get number of groups registered
+ * @pctldev:	pinctrl device representing IODelay device
+ *
+ * Return: number of groups mapped on the IODelay
+ */
+static int ti_iodelay_pinctrl_get_groups_count(struct pinctrl_dev *pctldev)
+{
+	struct ti_iodelay_device *iod;
+	struct device *dev;
+
+	iod = pinctrl_dev_get_drvdata(pctldev);
+	dev = iod->dev;
+
+	return iod->ngroups;
+}
+
+/**
+ * ti_iodelay_pinctrl_get_group_name() - Get the group name
+ * @pctldev:	pinctrl device representing IODelay device
+ * @gselector:	group selector
+ *
+ * Return: name of the Group given a valid gselector, else NULL.
+ */
+static const char *ti_iodelay_pinctrl_get_group_name(struct pinctrl_dev
+						     *pctldev,
+						     unsigned gselector)
+{
+	struct ti_iodelay_device *iod;
+	struct device *dev;
+	struct ti_iodelay_pingroup *group;
+
+	iod = pinctrl_dev_get_drvdata(pctldev);
+	dev = iod->dev;
+
+	group = ti_iodelay_get_group(iod, gselector);
+	if (!group)
+		return NULL;
+
+	return group->name;
+}
+
+/**
+ * ti_iodelay_pinctrl_get_group_pins() - get group pins
+ * @pctldev:	pinctrl device representing IODelay device
+ * @gselector: Group selector
+ * @pins:	pointer to the pins
+ * @npins:	number of pins
+ *
+ * Dummy implementation since we do not track pins, we track configurations
+ * Forced by pinctrl's pinctrl_check_ops()
+ *
+ * Return: -EINVAL
+ */
+static int ti_iodelay_pinctrl_get_group_pins(struct pinctrl_dev *pctldev,
+					     unsigned gselector,
+					     const unsigned **pins,
+					     unsigned *npins)
+{
+	/* Dummy implementation - we dont do pin mux */
+	return -EINVAL;
+}
+
+/**
+ * ti_iodelay_pinconf_group_get() - Get the group configuration
+ * @pctldev:	pinctrl device representing IODelay device
+ * @gselector:	Group selector
+ * @config:	configuration returned
+ *
+ * Return: The configuration if the group is valid, else returns -EINVAL
+ */
+static int ti_iodelay_pinconf_group_get(struct pinctrl_dev *pctldev,
+					unsigned gselector,
+					unsigned long *config)
+{
+	struct ti_iodelay_device *iod;
+	struct device *dev;
+	struct ti_iodelay_pingroup *group;
+
+	iod = pinctrl_dev_get_drvdata(pctldev);
+	dev = iod->dev;
+	group = ti_iodelay_get_group(iod, gselector);
+
+	if (!group)
+		return -EINVAL;
+
+	*config = group->config;
+	return 0;
+}
+
+/**
+ * ti_iodelay_pinconf_group_set() - Configure the groups of pins
+ * @pctldev:	pinctrl device representing IODelay device
+ * @gselector:	Group selector
+ * @configs:	Configurations
+ * @num_configs: Number of configurations
+ *
+ * Return: 0 if all went fine, else appropriate error value.
+ */
+static int ti_iodelay_pinconf_group_set(struct pinctrl_dev *pctldev,
+					unsigned gselector,
+					unsigned long *configs,
+					unsigned num_configs)
+{
+	struct ti_iodelay_device *iod;
+	struct device *dev;
+	struct ti_iodelay_pingroup *group;
+	int i;
+
+	iod = pinctrl_dev_get_drvdata(pctldev);
+	dev = iod->dev;
+	group = ti_iodelay_get_group(iod, gselector);
+
+	if (num_configs != 1) {
+		dev_err(dev, "Unsupported number of configurations %d\n",
+			num_configs);
+		return -EINVAL;
+	}
+
+	if (*configs != PIN_CONFIG_END) {
+		dev_err(dev, "Unsupported configuration\n");
+		return -EINVAL;
+	}
+
+	for (i = 0; i < group->nvals; i++) {
+		if (ti_iodelay_pinconf_set(iod, &group->vals[i]))
+			return -ENOTSUPP;
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_DEBUG_FS
+/**
+ * ti_iodelay_pinconf_group_dbg_show() - show the group information
+ * @pctldev:	Show the group information
+ * @s:	Sequence file
+ * @gselector:	group selector
+ *
+ * Provide the configuration information of the selected group
+ */
+static void ti_iodelay_pinconf_group_dbg_show(struct pinctrl_dev *pctldev,
+					      struct seq_file *s,
+					      unsigned gselector)
+{
+	struct ti_iodelay_device *iod;
+	struct device *dev;
+	struct ti_iodelay_pingroup *group;
+	int i;
+
+	iod = pinctrl_dev_get_drvdata(pctldev);
+	dev = iod->dev;
+	group = ti_iodelay_get_group(iod, gselector);
+	if (!group)
+		return;
+
+	for (i = 0; i < group->nvals; i++) {
+		struct ti_iodelay_conf_vals *val;
+		u32 reg = 0;
+
+		val = &group->vals[i];
+		regmap_read(iod->regmap, val->offset, &reg),
+		    seq_printf(s, "\n\t0x%08x = 0x%08x (%3d, %3d)",
+			       val->offset, reg, val->a_delay, val->g_delay);
+	}
+}
+#endif
+
+static struct pinctrl_ops ti_iodelay_pinctrl_ops = {
+	.dt_node_to_map = ti_iodelay_dt_node_to_map,
+	.dt_free_map = ti_iodelay_dt_free_map,
+	.get_groups_count = ti_iodelay_pinctrl_get_groups_count,
+	.get_group_name = ti_iodelay_pinctrl_get_group_name,
+	.get_group_pins = ti_iodelay_pinctrl_get_group_pins,
+};
+
+static struct pinconf_ops ti_iodelay_pinctrl_pinconf_ops = {
+	.pin_config_group_get = ti_iodelay_pinconf_group_get,
+	.pin_config_group_set = ti_iodelay_pinconf_group_set,
+#ifdef CONFIG_DEBUG_FS
+	.pin_config_group_dbg_show = ti_iodelay_pinconf_group_dbg_show,
+#endif
+};
+
+/**
+ * ti_iodelay_alloc_pins() - Allocate structures needed for pins for IOdelay
+ * @dev:	device pointer
+ * @iod:	IODelay device
+ * @base_phy:	Base Physical Address
+ *
+ * Return: 0 if all went fine, else appropriate error value.
+ */
+static int ti_iodelay_alloc_pins(struct device *dev,
+				 struct ti_iodelay_device *iod, u32 base_phy)
+{
+	const struct ti_iodelay_reg_data *r = iod->reg_data;
+	struct pinctrl_pin_desc *pin;
+	struct ti_iodelay_pin_name *pn;
+	u32 phy_reg;
+	int nr_pins, i;
+
+	nr_pins = (r->regmap_config->max_register - r->reg_start_offset) / 4;
+
+	dev_dbg(dev, "Allocating %i pins\n", nr_pins);
+
+	iod->pa = devm_kzalloc(dev, sizeof(*iod->pa) * nr_pins, GFP_KERNEL);
+	if (!iod->pa)
+		return -ENOMEM;
+
+	iod->names =
+	    devm_kzalloc(dev, sizeof(struct ti_iodelay_pin_name) * nr_pins,
+			 GFP_KERNEL);
+	if (!iod->names)
+		return -ENOMEM;
+
+	iod->desc.pins = iod->pa;
+	iod->desc.npins = nr_pins;
+
+	phy_reg = r->reg_start_offset + base_phy;
+	pn = iod->names;
+	for (i = 0; i < nr_pins; i++, pn++, phy_reg += 4) {
+		pin = &iod->pa[i];
+		sprintf(pn->name, "%x.%d", phy_reg, i);
+		pin->number = i;
+		pin->name = pn->name;
+	}
+
+	return 0;
+}
+
+/**
+ * ti_iodelay_probe() - Standard probe
+ * @pdev:	platform device
+ *
+ * Return: 0 if all went fine, else appropriate error value.
+ */
+static int ti_iodelay_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = of_node_get(dev->of_node);
+	const struct of_device_id *match;
+	struct resource *res;
+	struct ti_iodelay_device *iod;
+	int ret = 0;
+
+	if (!np) {
+		ret = -EINVAL;
+		dev_err(dev, "No OF node\n");
+		goto exit_out;
+	}
+
+	match = of_match_device(ti_iodelay_of_match, dev);
+	if (!match) {
+		ret = -EINVAL;
+		dev_err(dev, "No DATA match\n");
+		goto exit_out;
+	}
+
+	iod = devm_kzalloc(dev, sizeof(*iod), GFP_KERNEL);
+	if (!iod) {
+		ret = -ENOMEM;
+		goto exit_out;
+	}
+	iod->dev = dev;
+	iod->reg_data = match->data;
+
+	/* So far We can assume there is only 1 bank of registers */
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(dev, "Missing MEM resource\n");
+		ret = -ENODEV;
+		goto exit_out;
+	}
+
+	iod->reg_base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(iod->reg_base)) {
+		ret = PTR_ERR(iod->reg_base);
+		goto exit_out;
+	}
+
+	iod->regmap = devm_regmap_init_mmio(dev, iod->reg_base,
+					    iod->reg_data->regmap_config);
+	if (IS_ERR(iod->regmap)) {
+		dev_err(dev, "Regmap MMIO init failed.\n");
+		ret = PTR_ERR(iod->regmap);
+		goto exit_out;
+	}
+
+	if (ti_iodelay_pinconf_init_dev(iod))
+		goto exit_out;
+
+	ret = ti_iodelay_alloc_pins(dev, iod, res->start);
+	if (ret)
+		goto exit_out;
+
+	INIT_LIST_HEAD(&iod->groups);
+	mutex_init(&iod->mutex);
+
+	iod->desc.pctlops = &ti_iodelay_pinctrl_ops;
+	/* no pinmux ops - we are pinconf */
+	iod->desc.confops = &ti_iodelay_pinctrl_pinconf_ops;
+	iod->desc.name = dev_name(dev);
+	iod->desc.owner = THIS_MODULE;
+
+	iod->pctl = pinctrl_register(&iod->desc, dev, iod);
+	if (!iod->pctl) {
+		dev_err(dev, "Failed to register pinctrl\n");
+		ret = -ENODEV;
+		goto exit_out;
+	}
+
+	platform_set_drvdata(pdev, iod);
+
+exit_out:
+	of_node_put(np);
+	return ret;
+}
+
+/**
+ * ti_iodelay_remove() - standard remove
+ * @pdev:	platform device
+ *
+ * Return: 0 if all went fine, else appropriate error value.
+ */
+static int ti_iodelay_remove(struct platform_device *pdev)
+{
+	struct ti_iodelay_device *iod = platform_get_drvdata(pdev);
+
+	if (!iod)
+		return 0;
+	if (iod->pctl)
+		pinctrl_unregister(iod->pctl);
+
+	ti_iodelay_pinconf_deinit_dev(iod);
+
+	/* Expect other allocations to be freed by devm */
+
+	return 0;
+}
+
+static struct regmap_config dra7_iodelay_regmap_config = {
+	.reg_bits = 32,
+	.reg_stride = 4,
+	.val_bits = 32,
+	.max_register = 0xD1C,
+};
+
+static struct ti_iodelay_reg_data dra7_iodelay_data = {
+	.signature_mask = 0x0003F000,
+	.signature_value = 0x29,
+	.lock_mask = 0x00000400,
+	.lock_val = 1,
+	.unlock_val = 0,
+	.binary_data_coarse_mask = 0x000003E0,
+	.binary_data_fine_mask = 0x0000001F,
+
+	.reg_refclk_offset = 0x14,
+	.refclk_period_mask = 0xFFFF,
+
+	.reg_coarse_offset = 0x18,
+	.coarse_delay_count_mask = 0xFFFF0000,
+	.coarse_ref_count_mask = 0x0000FFFF,
+
+	.reg_fine_offset = 0x1C,
+	.fine_delay_count_mask = 0xFFFF0000,
+	.fine_ref_count_mask = 0x0000FFFF,
+
+	.reg_global_lock_offset = 0x2C,
+	.global_lock_mask = 0x0000FFFF,
+	.global_unlock_val = 0x0000AAAA,
+	.global_lock_val = 0x0000AAAB,
+
+	.reg_start_offset = 0x30,
+	.regmap_config = &dra7_iodelay_regmap_config,
+};
+
+static const struct of_device_id ti_iodelay_of_match[] = {
+	{.compatible = "ti,dra7-iodelay", .data = &dra7_iodelay_data},
+	{ /* Hopefully no more.. */ },
+};
+MODULE_DEVICE_TABLE(of, ti_iodelay_of_match);
+
+static struct platform_driver ti_iodelay_driver = {
+	.probe = ti_iodelay_probe,
+	.remove = ti_iodelay_remove,
+	.driver = {
+		   .owner = THIS_MODULE,
+		   .name = DRIVER_NAME,
+		   .of_match_table = ti_iodelay_of_match,
+		   },
+};
+module_platform_driver(ti_iodelay_driver);
+
+MODULE_AUTHOR("Texas Instruments, Inc.");
+MODULE_DESCRIPTION("Pinconf driver for TI's IO Delay module");
+MODULE_LICENSE("GPL v2");
diff --git a/include/dt-bindings/pinctrl/dra.h b/include/dt-bindings/pinctrl/dra.h
index 7448edff4723..0a26495c4df5 100644
--- a/include/dt-bindings/pinctrl/dra.h
+++ b/include/dt-bindings/pinctrl/dra.h
@@ -30,6 +30,8 @@
 #define MUX_MODE14	0xe
 #define MUX_MODE15	0xf
 
+#define MANUAL_MODE		MODE_SELECT
+
 #define PULL_ENA		(0 << 16)
 #define PULL_DIS		(1 << 16)
 #define PULL_UP			(1 << 17)
@@ -47,5 +49,9 @@
 #define PIN_INPUT_PULLUP	(PULL_ENA | INPUT_EN | PULL_UP)
 #define PIN_INPUT_PULLDOWN	(PULL_ENA | INPUT_EN)
 
+/* DRA7 IODELAY configuration parameters */
+#define A_DELAY(val)		((val) & 0xFFFF)
+#define G_DELAY(val)		(((val) & 0xFFFF) << 16)
+
 #endif
 
-- 
1.7.9.5

[PATCH 2/2] pinctrl: Introduce TI IOdelay configuration driver

[Nishanth Menon]

SoC family such as DRA7 family of processors have, in addition
to the regular muxing of pins (as done by pinctrl-single), an
additional hardware module called IODelay which is also expected to be
configured. This "IODelay" module has it's own register space that is
independent of the control module.

It is advocated strongly in TI's official documentation considering
the existing design of the DRA7 family of processors during mux or
IODelay reconfiguration, there is a potential for a significant glitch
which may cause functional impairment to certain hardware. It is
hence recommended to do as little of muxing as absolutely necessary
without I/O isolation (which can only be done in initial stages of
bootloader).

NOTE: with the system wide I/O isolation scheme present in DRA7 SoC
family, it is not reasonable to do stop all I/O operations for every
such pad configuration scheme. So, we will let it glitch when used in
this mode.

Even with the above limitation, certain functionality such as MMC has
mandatory need for IODelay reconfiguration requirements, depending on
speed of transfer. In these cases, with careful examination of usecase
involved, the expected glitch can be controlled such that it does not
impact functionality.

In short, IODelay module support as a padconf driver being introduced
here is not expected to do SoC wide I/O Isolation and is meant for
a limited subset of IODelay configuration requirements that need to
be dynamic and whose glitchy behavior will not cause functionality
failure for that interface.

Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
---
 drivers/pinctrl/Kconfig              |   11 +
 drivers/pinctrl/Makefile             |    1 +
 drivers/pinctrl/pinctrl-ti-iodelay.c |  963 ++++++++++++++++++++++++++++++++++
 include/dt-bindings/pinctrl/dra.h    |    6 +
 4 files changed, 981 insertions(+)
 create mode 100644 drivers/pinctrl/pinctrl-ti-iodelay.c

diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig
index ee9f44ad7f02..8e463d75fbb2 100644
--- a/drivers/pinctrl/Kconfig
+++ b/drivers/pinctrl/Kconfig
@@ -160,6 +160,17 @@ config PINCTRL_TEGRA_XUSB
 	select PINCONF
 	select PINMUX
 
+config PINCTRL_TI_IODELAY
+	bool "TI IODelay Module pinconf driver"
+	depends on OF
+	select PINCONF
+	select GENERIC_PINCONF
+	select REGMAP_MMIO
+	help
+	  Say Y here to support Texas Instruments' IODelay pinconf driver.
+	  IODelay module is used for the DRA7 SoC family. This driver is in
+	  addition to PINCTRL_SINGLE which controls the mux.
+
 config PINCTRL_TZ1090
 	bool "Toumaz Xenif TZ1090 pin control driver"
 	depends on SOC_TZ1090
diff --git a/drivers/pinctrl/Makefile b/drivers/pinctrl/Makefile
index 0475206dd600..e441cd71aedf 100644
--- a/drivers/pinctrl/Makefile
+++ b/drivers/pinctrl/Makefile
@@ -28,6 +28,7 @@ obj-$(CONFIG_PINCTRL_TEGRA30)	+= pinctrl-tegra30.o
 obj-$(CONFIG_PINCTRL_TEGRA114)	+= pinctrl-tegra114.o
 obj-$(CONFIG_PINCTRL_TEGRA124)	+= pinctrl-tegra124.o
 obj-$(CONFIG_PINCTRL_TEGRA_XUSB)	+= pinctrl-tegra-xusb.o
+obj-$(CONFIG_PINCTRL_TI_IODELAY)	+= pinctrl-ti-iodelay.o
 obj-$(CONFIG_PINCTRL_TZ1090)	+= pinctrl-tz1090.o
 obj-$(CONFIG_PINCTRL_TZ1090_PDC)	+= pinctrl-tz1090-pdc.o
 obj-$(CONFIG_PINCTRL_U300)	+= pinctrl-u300.o
diff --git a/drivers/pinctrl/pinctrl-ti-iodelay.c b/drivers/pinctrl/pinctrl-ti-iodelay.c
new file mode 100644
index 000000000000..e4c6e25a781c
--- /dev/null
+++ b/drivers/pinctrl/pinctrl-ti-iodelay.c
@@ -0,0 +1,963 @@
+/*
+ * Support for configuration of IO Delay module found on Texas Instruments SoCs
+ * such as DRA7
+ *
+ * Copyright (C) 2015 Texas Instruments, Inc.
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/of.h>
+#include <linux/pinctrl/pinconf-generic.h>
+#include <linux/pinctrl/pinconf.h>
+#include <linux/pinctrl/pinctrl.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+#define IODELAY_REG_NAME_LEN		((sizeof(u32) * 2) + 3)
+#define DRIVER_NAME			"ti-io-delay"
+/* Should I change this? Abuse? */
+#define IODELAY_MUX_PINS_NAME		"pinctrl-single,pins"
+
+/* Device tree match, populated later */
+static const struct of_device_id ti_iodelay_of_match[];
+
+/**
+ * struct ti_iodelay_conf_vals - Description of each configuration parameters.
+ * @offset:	Configuration register offset
+ * @a_delay:	Agnostic Delay (in ps)
+ * @g_delay:	Gnostic Delay (in ps)
+ */
+struct ti_iodelay_conf_vals {
+	u16 offset;
+	u16 a_delay;
+	u16 g_delay;
+};
+
+/**
+ * struct ti_iodelay_reg_data - Describes the registers for the IOdelay instance
+ * @signature_mask:	Conf reg- mask for the signature bits
+ * @signature_value:	Conf reg- signature value to be written (see TRM)
+ * @lock_mask:		Conf reg- mask for the lock bits
+ * @lock_val:		Conf reg- lock value for the lock bits (see TRM)
+ * @unlock_val:		Conf reg- unlock value for the lock bits (see TRM)
+ * @binary_data_coarse_mask: Conf reg- coarse mask (see TRM)
+ * @binary_data_fine_mask: Conf reg- fine mask (see TRM)
+ * @reg_refclk_offset:	Refclk register offset
+ * @refclk_period_mask:	Refclk mask
+ * @reg_coarse_offset:	Coarse register configuration offset
+ * @coarse_delay_count_mask: Coarse delay count mask
+ * @coarse_ref_count_mask: Coarse ref count mask
+ * @reg_fine_offset:	Fine register configuration offset
+ * @fine_delay_count_mask: Fine delay count mask
+ * @fine_ref_count_mask: Fine  ref count mask
+ * @reg_global_lock_offset: Global(for the IOdelay module) lock register offset
+ * @global_lock_mask:	Lock mask
+ * @global_unlock_val:	unlock value
+ * @global_lock_val:	lock value
+ * @reg_start_offset:	Where does the configuration registers start?
+ * @regmap_config:	Regmap configuration for the IODelay region
+ */
+struct ti_iodelay_reg_data {
+	u32 signature_mask;
+	u32 signature_value;
+	u32 lock_mask;
+	u32 lock_val;
+	u32 unlock_val;
+	u32 binary_data_coarse_mask;
+	u32 binary_data_fine_mask;
+
+	u32 reg_refclk_offset;
+	u32 refclk_period_mask;
+
+	u32 reg_coarse_offset;
+	u32 coarse_delay_count_mask;
+	u32 coarse_ref_count_mask;
+
+	u32 reg_fine_offset;
+	u32 fine_delay_count_mask;
+	u32 fine_ref_count_mask;
+
+	u32 reg_global_lock_offset;
+	u32 global_lock_mask;
+	u32 global_unlock_val;
+	u32 global_lock_val;
+
+	u32 reg_start_offset;
+
+	struct regmap_config *regmap_config;
+};
+
+/**
+ * struct ti_iodelay_reg_values - Computed io_reg configuration values (see TRM)
+ * @coarse_ref_count:	Coarse reference count
+ * @coarse_delay_count:	Coarse delay count
+ * @fine_ref_count:	Fine reference count
+ * @fine_delay_count:	Fine Delay count
+ * @ref_clk_period:	Reference Clock period
+ * @cdpe:		Coarse delay parameter
+ * @fdpe:		Fine delay parameter
+ */
+struct ti_iodelay_reg_values {
+	u16 coarse_ref_count;
+	u16 coarse_delay_count;
+
+	u16 fine_ref_count;
+	u16 fine_delay_count;
+
+	u16 ref_clk_period;
+
+	u32 cdpe;
+	u32 fdpe;
+};
+
+/**
+ * struct ti_iodelay_pin_name - name of the pins
+ * @name: name
+ */
+struct ti_iodelay_pin_name {
+	char name[IODELAY_REG_NAME_LEN];
+};
+
+/**
+ * struct ti_iodelay_pingroup - Structure that describes one group
+ * @np:		Node pointer (device tree)
+ * @name:	Name of the group
+ * @map:	pinctrl map allocated for the group
+ * @vals:	configuration values allocated for the group (from dt)
+ * @nvals:	number of configuration values allocated
+ * @config:	pinconf "Config" - currently a dummy value
+ * @node:	list node to next group
+ */
+struct ti_iodelay_pingroup {
+	struct device_node *np;
+	const char *name;
+	struct pinctrl_map *map;
+	struct ti_iodelay_conf_vals *vals;
+	int nvals;
+	unsigned long config;
+	struct list_head node;
+};
+
+/**
+ * struct ti_iodelay_device - Represents information for a IOdelay instance
+ * @dev: device pointer
+ * @reg_base: Remapped virtual address
+ * @regmap: Regmap for this IOdelay instance
+ * @pctl: Pinctrl device
+ * @desc: pinctrl descriptor for pctl
+ * @pa: pinctrl pin wise description
+ * @names: names of the pins
+ * @groups: list of pinconf groups for iodelay instance
+ * @ngroups: number of groups in the list
+ * @mutex: mutex to protect group list modification
+ * @reg_data: Register definition data for the IODelay instance
+ * @reg_init_conf_values: Initial configuration values.
+ */
+struct ti_iodelay_device {
+	struct device *dev;
+	void __iomem *reg_base;
+	struct regmap *regmap;
+
+	struct pinctrl_dev *pctl;
+	struct pinctrl_desc desc;
+	struct pinctrl_pin_desc *pa;
+	struct ti_iodelay_pin_name *names;
+
+	struct list_head groups;
+	int ngroups;
+	struct mutex mutex; /* list protection */
+
+	const struct ti_iodelay_reg_data *reg_data;
+	struct ti_iodelay_reg_values reg_init_conf_values;
+};
+
+/*--- IOdelay configuration stuff ----*/
+
+/**
+ * ti_iodelay_extract() - extract bits for a field
+ * @val:	register value
+ * @mask:	Mask
+ *
+ * Return: extracted value which is appropriately shifted
+ */
+static inline u32 ti_iodelay_extract(u32 val, u32 mask)
+{
+	return (val & mask) >> __ffs(mask);
+}
+
+/**
+ * ti_iodelay_compute_dpe() - Compute equation for delay parameter
+ * @period:	Period to use
+ * @ref:	Reference Count
+ * @delay:	Delay count
+ * @delay_m:	Delay multiplier
+ *
+ * Return: Computed delay parameter
+ */
+static inline u32 ti_iodelay_compute_dpe(u16 period, u16 ref, u16 delay,
+					 u16 delay_m)
+{
+	u64 m, d;
+
+	/* Handle overflow conditions */
+	m = 10 * (u64)period * (u64)ref;
+	d = 2 * (u64)delay * (u64)delay_m;
+
+	/* Truncate result back to 32 bits */
+	return div64_u64(m, d);
+}
+
+/**
+ * ti_iodelay_pinconf_set() - Configure the pin configuration
+ * @iod:	IODelay device
+ * @val:	Configuration value
+ *
+ * Update the configuration register as per TRM and lockup once done.
+ * *IMPORTANT NOTE* SoC TRM does recommend doing iodelay programmation only
+ * while in Isolation. But, then, isolation also implies that every pin
+ * on the SoC(including DDR) will be isolated out. The only benefit being
+ * a glitchless configuration, However, the intent of this driver is purely
+ * to support a "glitchy" configuration where applicable.
+ *
+ * Return: 0 in case of success, else appropriate error value
+ */
+static int ti_iodelay_pinconf_set(struct ti_iodelay_device *iod,
+				  struct ti_iodelay_conf_vals *val)
+{
+	const struct ti_iodelay_reg_data *reg = iod->reg_data;
+	struct ti_iodelay_reg_values *ival = &iod->reg_init_conf_values;
+	struct device *dev = iod->dev;
+	u32 g_delay_coarse, g_delay_fine;
+	u32 a_delay_coarse, a_delay_fine;
+	u32 c_elements, f_elements;
+	u32 total_delay;
+	u32 reg_mask, reg_val, tmp_val;
+	int r;
+
+	/* NOTE: Truncation is expected in all division below */
+	g_delay_coarse = val->g_delay / 920;
+	g_delay_fine = ((val->g_delay % 920) * 10) / 60;
+
+	a_delay_coarse = val->a_delay / ival->cdpe;
+	a_delay_fine = ((val->a_delay % ival->cdpe) * 10) / ival->fdpe;
+
+	c_elements = g_delay_coarse + a_delay_coarse;
+	f_elements = (g_delay_fine + a_delay_fine) / 10;
+
+	if (f_elements > 22) {
+		total_delay = c_elements * ival->cdpe + f_elements * ival->fdpe;
+		c_elements = total_delay / ival->cdpe;
+		f_elements = (total_delay % ival->cdpe) / ival->fdpe;
+	}
+
+	reg_mask = reg->signature_mask;
+	reg_val = reg->signature_value << __ffs(reg->signature_mask);
+
+	reg_mask |= reg->binary_data_coarse_mask;
+	tmp_val = c_elements << __ffs(reg->binary_data_coarse_mask);
+	if (tmp_val & ~reg->binary_data_coarse_mask) {
+		dev_err(dev, "Masking overflow of coarse elements %08x\n",
+			tmp_val);
+		tmp_val &= reg->binary_data_coarse_mask;
+	}
+	reg_val |= tmp_val;
+
+	reg_mask |= reg->binary_data_fine_mask;
+	tmp_val = f_elements << __ffs(reg->binary_data_fine_mask);
+	if (tmp_val & ~reg->binary_data_fine_mask) {
+		dev_err(dev, "Masking overflow of fine elements %08x\n",
+			tmp_val);
+		tmp_val &= reg->binary_data_fine_mask;
+	}
+	reg_val |= tmp_val;
+
+	/* Write with lock value - we DONOT want h/w updates */
+	reg_mask |= reg->lock_mask;
+	reg_val |= reg->lock_val << __ffs(reg->lock_mask);
+	r = regmap_update_bits(iod->regmap, val->offset, reg_mask, reg_val);
+
+	dev_dbg(dev, "Set reg 0x%x Delay(a=%d g=%d), Elements(C=%d F=%d)0x%x\n",
+		val->offset, val->a_delay, val->g_delay, c_elements,
+		f_elements, reg_val);
+
+	return r;
+}
+
+/**
+ * ti_iodelay_pinconf_init_dev() - Initialize IODelay device
+ * @iod:	IODelay device
+ *
+ * Unlocks the IODelay region, computes the common parameters
+ *
+ * Return: 0 in case of success, else appropriate error value
+ */
+static int ti_iodelay_pinconf_init_dev(struct ti_iodelay_device *iod)
+{
+	const struct ti_iodelay_reg_data *reg = iod->reg_data;
+	struct device *dev = iod->dev;
+	struct ti_iodelay_reg_values *ival = &iod->reg_init_conf_values;
+	u32 val;
+	int r;
+
+	/* unlock the IOdelay region */
+	r = regmap_update_bits(iod->regmap, reg->reg_global_lock_offset,
+			       reg->global_lock_mask, reg->global_unlock_val);
+	if (r)
+		return r;
+
+	/* Read up Recalibration sequence done by bootloader */
+	r = regmap_read(iod->regmap, reg->reg_refclk_offset, &val);
+	if (r)
+		return r;
+	ival->ref_clk_period = ti_iodelay_extract(val, reg->refclk_period_mask);
+	dev_dbg(dev, "refclk_period=0x%04x\n", ival->ref_clk_period);
+
+	r = regmap_read(iod->regmap, reg->reg_coarse_offset, &val);
+	if (r)
+		return r;
+	ival->coarse_ref_count =
+	    ti_iodelay_extract(val, reg->coarse_ref_count_mask);
+	ival->coarse_delay_count =
+	    ti_iodelay_extract(val, reg->coarse_delay_count_mask);
+	if (!ival->coarse_delay_count) {
+		dev_err(dev, "Invalid Coarse delay count (0) (reg=0x%08x)\n",
+			val);
+		return -EINVAL;
+	}
+	ival->cdpe = ti_iodelay_compute_dpe(ival->ref_clk_period,
+					    ival->coarse_ref_count,
+					    ival->coarse_delay_count, 88);
+	if (!ival->cdpe) {
+		dev_err(dev, "Invalid cdpe computed params = %d %d %d\n",
+			ival->ref_clk_period, ival->coarse_ref_count,
+			ival->coarse_delay_count);
+		return -EINVAL;
+	}
+	dev_dbg(iod->dev, "coarse: ref=0x%04x delay=0x%04x cdpe=0x%08x\n",
+		ival->coarse_ref_count, ival->coarse_delay_count, ival->cdpe);
+
+	r = regmap_read(iod->regmap, reg->reg_fine_offset, &val);
+	if (r)
+		return r;
+	ival->fine_ref_count =
+	    ti_iodelay_extract(val, reg->fine_ref_count_mask);
+	ival->fine_delay_count =
+	    ti_iodelay_extract(val, reg->fine_delay_count_mask);
+	if (!ival->fine_delay_count) {
+		dev_err(dev, "Invalid Fine delay count (0) (reg=0x%08x)\n",
+			val);
+		return -EINVAL;
+	}
+	ival->fdpe = ti_iodelay_compute_dpe(ival->ref_clk_period,
+					    ival->fine_ref_count,
+					    ival->fine_delay_count, 264);
+	if (!ival->fdpe) {
+		dev_err(dev, "Invalid fdpe(0) computed params = %d %d %d\n",
+			ival->ref_clk_period, ival->fine_ref_count,
+			ival->fine_delay_count);
+		return -EINVAL;
+	}
+	dev_dbg(iod->dev, "fine: ref=0x%04x delay=0x%04x fdpe=0x%08x\n",
+		ival->fine_ref_count, ival->fine_delay_count, ival->fdpe);
+
+	return 0;
+}
+
+/**
+ * ti_iodelay_pinconf_deinit_dev() - deinit the IOdelay device
+ * @iod:	IODelay device
+ *
+ * Deinitialize the IODelay device (basically just lock the region back up.
+ */
+static void ti_iodelay_pinconf_deinit_dev(struct ti_iodelay_device *iod)
+{
+	const struct ti_iodelay_reg_data *reg = iod->reg_data;
+
+	/* lock the IOdelay region back again */
+	regmap_update_bits(iod->regmap, reg->reg_global_lock_offset,
+			   reg->global_lock_mask, reg->global_lock_val);
+}
+
+/*--- Pinctrl/pinconf framework stuff ----*/
+
+/**
+ * ti_iodelay_get_group() - Find the group mapped by a group selector
+ * @iod:	IODelay device
+ * @gselector:	Group Selector
+ *
+ * Return: Corresponding group representing group selector in list of groups
+ * managed in IOdelay device OR NULL if not found.
+ */
+static struct ti_iodelay_pingroup *ti_iodelay_get_group(struct ti_iodelay_device
+							*iod,
+							unsigned gselector)
+{
+	struct ti_iodelay_pingroup *group;
+	int gid = 0;
+
+	list_for_each_entry(group, &iod->groups, node) {
+		if (gid == gselector)
+			return group;
+		gid++;
+	}
+
+	dev_err(iod->dev, "%s could not find pingroup %i\n", __func__,
+		gselector);
+	return NULL;
+}
+
+/**
+ * ti_iodelay_dt_node_to_map() - Map a device tree node to appropriate group
+ * @pctldev:	pinctrl device representing IODelay device
+ * @np:		Node Pointer (device tree)
+ * @map:	Pinctrl Map returned back to pinctrl framework
+ * @num_maps:	Number of maps (1)
+ *
+ * Maps the device tree description into a group of configuration parameters
+ * for IOdelay block entry.
+ *
+ * Return: 0 in case of success, else appropriate error value
+ */
+static int ti_iodelay_dt_node_to_map(struct pinctrl_dev *pctldev,
+				     struct device_node *np,
+				     struct pinctrl_map **map,
+				     unsigned *num_maps)
+{
+	struct ti_iodelay_device *iod;
+	struct device *dev;
+	/* const char **pgnames; */
+	int ret = 0;
+	const __be32 *mux;
+	struct ti_iodelay_conf_vals *vals;
+	struct ti_iodelay_pingroup *group;
+	int size, index, idx, rows;
+	u32 offset, val;
+
+	iod = pinctrl_dev_get_drvdata(pctldev);
+	if (!iod)
+		return -EINVAL;
+	dev = iod->dev;
+
+	*map = devm_kzalloc(dev, sizeof(**map), GFP_KERNEL);
+	if (!*map)
+		return -ENOMEM;
+	*num_maps = 0;
+
+	group = devm_kzalloc(dev, sizeof(*group), GFP_KERNEL);
+	if (!group) {
+		ret = -ENOMEM;
+		goto free_map;
+	}
+
+	mux = of_get_property(np, IODELAY_MUX_PINS_NAME, &size);
+	if ((!mux) || (size < sizeof(*mux) * 2)) {
+		dev_err(dev, "bad data for mux %s\n", np->name);
+		ret = -EINVAL;
+		goto free_group;
+	}
+
+	size /= sizeof(*mux);	/* Number of elements in array */
+	rows = size / 2;
+
+	vals = devm_kzalloc(dev, sizeof(*vals) * rows, GFP_KERNEL);
+	if (!vals) {
+		ret = -ENOMEM;
+		goto free_group;
+	}
+
+	index = 0;
+	idx = 0;
+	while (index < size) {
+		offset = be32_to_cpup(mux + index++);
+		val = be32_to_cpup(mux + index++);
+		vals[idx].offset = offset;
+		vals[idx].a_delay = val & 0xFFFF;
+		vals[idx].g_delay = (val & 0xFFFF0000) >> 16;
+		if (offset > iod->reg_data->regmap_config->max_register) {
+			dev_err(dev, "Invalid offset for %s 0x%x\n",
+				np->name, offset);
+			break;
+		}
+		dev_dbg(dev, "%s offset=%x a_delay = %d g_delay = %d\n",
+			np->name, vals[idx].offset, vals[idx].a_delay,
+			vals[idx].g_delay);
+		idx++;
+	}
+
+	group->name = np->name;
+	group->np = np;
+	group->vals = vals;
+	group->nvals = idx;
+	group->config = PIN_CONFIG_END;
+	group->map = *map;
+
+	/* Add to group list */
+	mutex_lock(&iod->mutex);
+	list_add_tail(&group->node, &iod->groups);
+	iod->ngroups++;
+	mutex_unlock(&iod->mutex);
+
+	(*map)->type = PIN_MAP_TYPE_CONFIGS_GROUP;
+	(*map)->data.configs.group_or_pin = np->name;
+	(*map)->data.configs.configs = &group->config;
+	(*map)->data.configs.num_configs = 1;
+	*num_maps = 1;
+
+	return 0;
+
+free_group:
+	devm_kfree(dev, group);
+free_map:
+	devm_kfree(dev, *map);
+	return ret;
+}
+
+/**
+ * ti_iodelay_dt_free_map() - Free map and resource alloted as per the map
+ * @pctldev:	pinctrl device representing IODelay device
+ * @map:	Map allocated by ti_iodelay_dt_node_to_map
+ * @num_maps:	Num maps (1)
+ *
+ * Removes the group associated with the map and frees all resources allocated
+ * for the group.
+ */
+static void ti_iodelay_dt_free_map(struct pinctrl_dev *pctldev,
+				   struct pinctrl_map *map, unsigned num_maps)
+{
+	struct ti_iodelay_device *iod;
+	struct device *dev;
+	struct ti_iodelay_pingroup *group;
+	bool found = false;
+
+	if (!map)
+		return;
+
+	iod = pinctrl_dev_get_drvdata(pctldev);
+	if (!iod)
+		return;
+	dev = iod->dev;
+
+	mutex_lock(&iod->mutex);
+	list_for_each_entry(group, &iod->groups, node) {
+		if (group->map == map) {
+			found = true;
+			list_del(&group->node);
+			iod->ngroups--;
+			break;
+		}
+	}
+	mutex_unlock(&iod->mutex);
+
+	/* If some freaky pinconf framework bug... */
+	if (!found)
+		return;
+
+	devm_kfree(dev, group->vals);
+	devm_kfree(dev, group);
+	devm_kfree(dev, map);
+}
+
+/**
+ * ti_iodelay_pinctrl_get_groups_count() - Get number of groups registered
+ * @pctldev:	pinctrl device representing IODelay device
+ *
+ * Return: number of groups mapped on the IODelay
+ */
+static int ti_iodelay_pinctrl_get_groups_count(struct pinctrl_dev *pctldev)
+{
+	struct ti_iodelay_device *iod;
+	struct device *dev;
+
+	iod = pinctrl_dev_get_drvdata(pctldev);
+	dev = iod->dev;
+
+	return iod->ngroups;
+}
+
+/**
+ * ti_iodelay_pinctrl_get_group_name() - Get the group name
+ * @pctldev:	pinctrl device representing IODelay device
+ * @gselector:	group selector
+ *
+ * Return: name of the Group given a valid gselector, else NULL.
+ */
+static const char *ti_iodelay_pinctrl_get_group_name(struct pinctrl_dev
+						     *pctldev,
+						     unsigned gselector)
+{
+	struct ti_iodelay_device *iod;
+	struct device *dev;
+	struct ti_iodelay_pingroup *group;
+
+	iod = pinctrl_dev_get_drvdata(pctldev);
+	dev = iod->dev;
+
+	group = ti_iodelay_get_group(iod, gselector);
+	if (!group)
+		return NULL;
+
+	return group->name;
+}
+
+/**
+ * ti_iodelay_pinctrl_get_group_pins() - get group pins
+ * @pctldev:	pinctrl device representing IODelay device
+ * @gselector: Group selector
+ * @pins:	pointer to the pins
+ * @npins:	number of pins
+ *
+ * Dummy implementation since we do not track pins, we track configurations
+ * Forced by pinctrl's pinctrl_check_ops()
+ *
+ * Return: -EINVAL
+ */
+static int ti_iodelay_pinctrl_get_group_pins(struct pinctrl_dev *pctldev,
+					     unsigned gselector,
+					     const unsigned **pins,
+					     unsigned *npins)
+{
+	/* Dummy implementation - we dont do pin mux */
+	return -EINVAL;
+}
+
+/**
+ * ti_iodelay_pinconf_group_get() - Get the group configuration
+ * @pctldev:	pinctrl device representing IODelay device
+ * @gselector:	Group selector
+ * @config:	configuration returned
+ *
+ * Return: The configuration if the group is valid, else returns -EINVAL
+ */
+static int ti_iodelay_pinconf_group_get(struct pinctrl_dev *pctldev,
+					unsigned gselector,
+					unsigned long *config)
+{
+	struct ti_iodelay_device *iod;
+	struct device *dev;
+	struct ti_iodelay_pingroup *group;
+
+	iod = pinctrl_dev_get_drvdata(pctldev);
+	dev = iod->dev;
+	group = ti_iodelay_get_group(iod, gselector);
+
+	if (!group)
+		return -EINVAL;
+
+	*config = group->config;
+	return 0;
+}
+
+/**
+ * ti_iodelay_pinconf_group_set() - Configure the groups of pins
+ * @pctldev:	pinctrl device representing IODelay device
+ * @gselector:	Group selector
+ * @configs:	Configurations
+ * @num_configs: Number of configurations
+ *
+ * Return: 0 if all went fine, else appropriate error value.
+ */
+static int ti_iodelay_pinconf_group_set(struct pinctrl_dev *pctldev,
+					unsigned gselector,
+					unsigned long *configs,
+					unsigned num_configs)
+{
+	struct ti_iodelay_device *iod;
+	struct device *dev;
+	struct ti_iodelay_pingroup *group;
+	int i;
+
+	iod = pinctrl_dev_get_drvdata(pctldev);
+	dev = iod->dev;
+	group = ti_iodelay_get_group(iod, gselector);
+
+	if (num_configs != 1) {
+		dev_err(dev, "Unsupported number of configurations %d\n",
+			num_configs);
+		return -EINVAL;
+	}
+
+	if (*configs != PIN_CONFIG_END) {
+		dev_err(dev, "Unsupported configuration\n");
+		return -EINVAL;
+	}
+
+	for (i = 0; i < group->nvals; i++) {
+		if (ti_iodelay_pinconf_set(iod, &group->vals[i]))
+			return -ENOTSUPP;
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_DEBUG_FS
+/**
+ * ti_iodelay_pinconf_group_dbg_show() - show the group information
+ * @pctldev:	Show the group information
+ * @s:	Sequence file
+ * @gselector:	group selector
+ *
+ * Provide the configuration information of the selected group
+ */
+static void ti_iodelay_pinconf_group_dbg_show(struct pinctrl_dev *pctldev,
+					      struct seq_file *s,
+					      unsigned gselector)
+{
+	struct ti_iodelay_device *iod;
+	struct device *dev;
+	struct ti_iodelay_pingroup *group;
+	int i;
+
+	iod = pinctrl_dev_get_drvdata(pctldev);
+	dev = iod->dev;
+	group = ti_iodelay_get_group(iod, gselector);
+	if (!group)
+		return;
+
+	for (i = 0; i < group->nvals; i++) {
+		struct ti_iodelay_conf_vals *val;
+		u32 reg = 0;
+
+		val = &group->vals[i];
+		regmap_read(iod->regmap, val->offset, &reg),
+		    seq_printf(s, "\n\t0x%08x = 0x%08x (%3d, %3d)",
+			       val->offset, reg, val->a_delay, val->g_delay);
+	}
+}
+#endif
+
+static struct pinctrl_ops ti_iodelay_pinctrl_ops = {
+	.dt_node_to_map = ti_iodelay_dt_node_to_map,
+	.dt_free_map = ti_iodelay_dt_free_map,
+	.get_groups_count = ti_iodelay_pinctrl_get_groups_count,
+	.get_group_name = ti_iodelay_pinctrl_get_group_name,
+	.get_group_pins = ti_iodelay_pinctrl_get_group_pins,
+};
+
+static struct pinconf_ops ti_iodelay_pinctrl_pinconf_ops = {
+	.pin_config_group_get = ti_iodelay_pinconf_group_get,
+	.pin_config_group_set = ti_iodelay_pinconf_group_set,
+#ifdef CONFIG_DEBUG_FS
+	.pin_config_group_dbg_show = ti_iodelay_pinconf_group_dbg_show,
+#endif
+};
+
+/**
+ * ti_iodelay_alloc_pins() - Allocate structures needed for pins for IOdelay
+ * @dev:	device pointer
+ * @iod:	IODelay device
+ * @base_phy:	Base Physical Address
+ *
+ * Return: 0 if all went fine, else appropriate error value.
+ */
+static int ti_iodelay_alloc_pins(struct device *dev,
+				 struct ti_iodelay_device *iod, u32 base_phy)
+{
+	const struct ti_iodelay_reg_data *r = iod->reg_data;
+	struct pinctrl_pin_desc *pin;
+	struct ti_iodelay_pin_name *pn;
+	u32 phy_reg;
+	int nr_pins, i;
+
+	nr_pins = (r->regmap_config->max_register - r->reg_start_offset) / 4;
+
+	dev_dbg(dev, "Allocating %i pins\n", nr_pins);
+
+	iod->pa = devm_kzalloc(dev, sizeof(*iod->pa) * nr_pins, GFP_KERNEL);
+	if (!iod->pa)
+		return -ENOMEM;
+
+	iod->names =
+	    devm_kzalloc(dev, sizeof(struct ti_iodelay_pin_name) * nr_pins,
+			 GFP_KERNEL);
+	if (!iod->names)
+		return -ENOMEM;
+
+	iod->desc.pins = iod->pa;
+	iod->desc.npins = nr_pins;
+
+	phy_reg = r->reg_start_offset + base_phy;
+	pn = iod->names;
+	for (i = 0; i < nr_pins; i++, pn++, phy_reg += 4) {
+		pin = &iod->pa[i];
+		sprintf(pn->name, "%x.%d", phy_reg, i);
+		pin->number = i;
+		pin->name = pn->name;
+	}
+
+	return 0;
+}
+
+/**
+ * ti_iodelay_probe() - Standard probe
+ * @pdev:	platform device
+ *
+ * Return: 0 if all went fine, else appropriate error value.
+ */
+static int ti_iodelay_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = of_node_get(dev->of_node);
+	const struct of_device_id *match;
+	struct resource *res;
+	struct ti_iodelay_device *iod;
+	int ret = 0;
+
+	if (!np) {
+		ret = -EINVAL;
+		dev_err(dev, "No OF node\n");
+		goto exit_out;
+	}
+
+	match = of_match_device(ti_iodelay_of_match, dev);
+	if (!match) {
+		ret = -EINVAL;
+		dev_err(dev, "No DATA match\n");
+		goto exit_out;
+	}
+
+	iod = devm_kzalloc(dev, sizeof(*iod), GFP_KERNEL);
+	if (!iod) {
+		ret = -ENOMEM;
+		goto exit_out;
+	}
+	iod->dev = dev;
+	iod->reg_data = match->data;
+
+	/* So far We can assume there is only 1 bank of registers */
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(dev, "Missing MEM resource\n");
+		ret = -ENODEV;
+		goto exit_out;
+	}
+
+	iod->reg_base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(iod->reg_base)) {
+		ret = PTR_ERR(iod->reg_base);
+		goto exit_out;
+	}
+
+	iod->regmap = devm_regmap_init_mmio(dev, iod->reg_base,
+					    iod->reg_data->regmap_config);
+	if (IS_ERR(iod->regmap)) {
+		dev_err(dev, "Regmap MMIO init failed.\n");
+		ret = PTR_ERR(iod->regmap);
+		goto exit_out;
+	}
+
+	if (ti_iodelay_pinconf_init_dev(iod))
+		goto exit_out;
+
+	ret = ti_iodelay_alloc_pins(dev, iod, res->start);
+	if (ret)
+		goto exit_out;
+
+	INIT_LIST_HEAD(&iod->groups);
+	mutex_init(&iod->mutex);
+
+	iod->desc.pctlops = &ti_iodelay_pinctrl_ops;
+	/* no pinmux ops - we are pinconf */
+	iod->desc.confops = &ti_iodelay_pinctrl_pinconf_ops;
+	iod->desc.name = dev_name(dev);
+	iod->desc.owner = THIS_MODULE;
+
+	iod->pctl = pinctrl_register(&iod->desc, dev, iod);
+	if (!iod->pctl) {
+		dev_err(dev, "Failed to register pinctrl\n");
+		ret = -ENODEV;
+		goto exit_out;
+	}
+
+	platform_set_drvdata(pdev, iod);
+
+exit_out:
+	of_node_put(np);
+	return ret;
+}
+
+/**
+ * ti_iodelay_remove() - standard remove
+ * @pdev:	platform device
+ *
+ * Return: 0 if all went fine, else appropriate error value.
+ */
+static int ti_iodelay_remove(struct platform_device *pdev)
+{
+	struct ti_iodelay_device *iod = platform_get_drvdata(pdev);
+
+	if (!iod)
+		return 0;
+	if (iod->pctl)
+		pinctrl_unregister(iod->pctl);
+
+	ti_iodelay_pinconf_deinit_dev(iod);
+
+	/* Expect other allocations to be freed by devm */
+
+	return 0;
+}
+
+static struct regmap_config dra7_iodelay_regmap_config = {
+	.reg_bits = 32,
+	.reg_stride = 4,
+	.val_bits = 32,
+	.max_register = 0xD1C,
+};
+
+static struct ti_iodelay_reg_data dra7_iodelay_data = {
+	.signature_mask = 0x0003F000,
+	.signature_value = 0x29,
+	.lock_mask = 0x00000400,
+	.lock_val = 1,
+	.unlock_val = 0,
+	.binary_data_coarse_mask = 0x000003E0,
+	.binary_data_fine_mask = 0x0000001F,
+
+	.reg_refclk_offset = 0x14,
+	.refclk_period_mask = 0xFFFF,
+
+	.reg_coarse_offset = 0x18,
+	.coarse_delay_count_mask = 0xFFFF0000,
+	.coarse_ref_count_mask = 0x0000FFFF,
+
+	.reg_fine_offset = 0x1C,
+	.fine_delay_count_mask = 0xFFFF0000,
+	.fine_ref_count_mask = 0x0000FFFF,
+
+	.reg_global_lock_offset = 0x2C,
+	.global_lock_mask = 0x0000FFFF,
+	.global_unlock_val = 0x0000AAAA,
+	.global_lock_val = 0x0000AAAB,
+
+	.reg_start_offset = 0x30,
+	.regmap_config = &dra7_iodelay_regmap_config,
+};
+
+static const struct of_device_id ti_iodelay_of_match[] = {
+	{.compatible = "ti,dra7-iodelay", .data = &dra7_iodelay_data},
+	{ /* Hopefully no more.. */ },
+};
+MODULE_DEVICE_TABLE(of, ti_iodelay_of_match);
+
+static struct platform_driver ti_iodelay_driver = {
+	.probe = ti_iodelay_probe,
+	.remove = ti_iodelay_remove,
+	.driver = {
+		   .owner = THIS_MODULE,
+		   .name = DRIVER_NAME,
+		   .of_match_table = ti_iodelay_of_match,
+		   },
+};
+module_platform_driver(ti_iodelay_driver);
+
+MODULE_AUTHOR("Texas Instruments, Inc.");
+MODULE_DESCRIPTION("Pinconf driver for TI's IO Delay module");
+MODULE_LICENSE("GPL v2");
diff --git a/include/dt-bindings/pinctrl/dra.h b/include/dt-bindings/pinctrl/dra.h
index 7448edff4723..0a26495c4df5 100644
--- a/include/dt-bindings/pinctrl/dra.h
+++ b/include/dt-bindings/pinctrl/dra.h
@@ -30,6 +30,8 @@
 #define MUX_MODE14	0xe
 #define MUX_MODE15	0xf
 
+#define MANUAL_MODE		MODE_SELECT
+
 #define PULL_ENA		(0 << 16)
 #define PULL_DIS		(1 << 16)
 #define PULL_UP			(1 << 17)
@@ -47,5 +49,9 @@
 #define PIN_INPUT_PULLUP	(PULL_ENA | INPUT_EN | PULL_UP)
 #define PIN_INPUT_PULLDOWN	(PULL_ENA | INPUT_EN)
 
+/* DRA7 IODELAY configuration parameters */
+#define A_DELAY(val)		((val) & 0xFFFF)
+#define G_DELAY(val)		(((val) & 0xFFFF) << 16)
+
 #endif
 
-- 
1.7.9.5

Re: [PATCH 2/2] pinctrl: Introduce TI IOdelay configuration driver

[Paul Bolle]

Nishanth Menon schreef op di 03-03-2015 om 18:00 [-0600]:
> diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig
> index ee9f44ad7f02..8e463d75fbb2 100644
> --- a/drivers/pinctrl/Kconfig
> +++ b/drivers/pinctrl/Kconfig
> @@ -160,6 +160,17 @@ config PINCTRL_TEGRA_XUSB
>  	select PINCONF
>  	select PINMUX
>  
> +config PINCTRL_TI_IODELAY
> +	bool "TI IODelay Module pinconf driver"

This adds a boolean Kconfig symbol.

> +	depends on OF
> +	select PINCONF
> +	select GENERIC_PINCONF
> +	select REGMAP_MMIO
> +	help
> +	  Say Y here to support Texas Instruments' IODelay pinconf driver.
> +	  IODelay module is used for the DRA7 SoC family. This driver is in
> +	  addition to PINCTRL_SINGLE which controls the mux.
> +
>  config PINCTRL_TZ1090
>  	bool "Toumaz Xenif TZ1090 pin control driver"
>  	depends on SOC_TZ1090
> diff --git a/drivers/pinctrl/Makefile b/drivers/pinctrl/Makefile
> index 0475206dd600..e441cd71aedf 100644
> --- a/drivers/pinctrl/Makefile
> +++ b/drivers/pinctrl/Makefile
> @@ -28,6 +28,7 @@ obj-$(CONFIG_PINCTRL_TEGRA30)	+= pinctrl-tegra30.o
>  obj-$(CONFIG_PINCTRL_TEGRA114)	+= pinctrl-tegra114.o
>  obj-$(CONFIG_PINCTRL_TEGRA124)	+= pinctrl-tegra124.o
>  obj-$(CONFIG_PINCTRL_TEGRA_XUSB)	+= pinctrl-tegra-xusb.o
> +obj-$(CONFIG_PINCTRL_TI_IODELAY)	+= pinctrl-ti-iodelay.o

So this objectfile will either be built-in or not be built at all.

>  obj-$(CONFIG_PINCTRL_TZ1090)	+= pinctrl-tz1090.o
>  obj-$(CONFIG_PINCTRL_TZ1090_PDC)	+= pinctrl-tz1090-pdc.o
>  obj-$(CONFIG_PINCTRL_U300)	+= pinctrl-u300.o
> diff --git a/drivers/pinctrl/pinctrl-ti-iodelay.c b/drivers/pinctrl/pinctrl-ti-iodelay.c
> new file mode 100644
> index 000000000000..e4c6e25a781c
> --- /dev/null
> +++ b/drivers/pinctrl/pinctrl-ti-iodelay.c
> @@ -0,0 +1,963 @@
>[...]
> +#include <linux/err.h>
> +#include <linux/init.h>
> +#include <linux/io.h>
> +#include <linux/list.h>
> +#include <linux/module.h>

This is, I think, a bit of a red flag.

> +#include <linux/of_device.h>
> +#include <linux/of.h>
> +#include <linux/pinctrl/pinconf-generic.h>
> +#include <linux/pinctrl/pinconf.h>
> +#include <linux/pinctrl/pinctrl.h>
> +#include <linux/regmap.h>
> +#include <linux/slab.h>

[...]

> +static const struct of_device_id ti_iodelay_of_match[] = {
> +	{.compatible = "ti,dra7-iodelay", .data = &dra7_iodelay_data},
> +	{ /* Hopefully no more.. */ },
> +};
> +MODULE_DEVICE_TABLE(of, ti_iodelay_of_match);
> +
> +static struct platform_driver ti_iodelay_driver = {
> +	.probe = ti_iodelay_probe,
> +	.remove = ti_iodelay_remove,
> +	.driver = {
> +		   .owner = THIS_MODULE,

So THIS_MODULE will, basically, be NULL.

> +		   .name = DRIVER_NAME,
> +		   .of_match_table = ti_iodelay_of_match,
> +		   },
> +};
> +module_platform_driver(ti_iodelay_driver);
> +
> +MODULE_AUTHOR("Texas Instruments, Inc.");
> +MODULE_DESCRIPTION("Pinconf driver for TI's IO Delay module");
> +MODULE_LICENSE("GPL v2");

And these three macros will be preprocessed away.

(Perhaps there are non-modular alternatives to MODULE_DEVICE_TABLE and
module_platform_driver, but I'm not sure how those two macros actually
work.)


Paul Bolle

[PATCH 2/2] pinctrl: Introduce TI IOdelay configuration driver

[Paul Bolle]

Nishanth Menon schreef op di 03-03-2015 om 18:00 [-0600]:
> diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig
> index ee9f44ad7f02..8e463d75fbb2 100644
> --- a/drivers/pinctrl/Kconfig
> +++ b/drivers/pinctrl/Kconfig
> @@ -160,6 +160,17 @@ config PINCTRL_TEGRA_XUSB
>  	select PINCONF
>  	select PINMUX
>  
> +config PINCTRL_TI_IODELAY
> +	bool "TI IODelay Module pinconf driver"

This adds a boolean Kconfig symbol.

> +	depends on OF
> +	select PINCONF
> +	select GENERIC_PINCONF
> +	select REGMAP_MMIO
> +	help
> +	  Say Y here to support Texas Instruments' IODelay pinconf driver.
> +	  IODelay module is used for the DRA7 SoC family. This driver is in
> +	  addition to PINCTRL_SINGLE which controls the mux.
> +
>  config PINCTRL_TZ1090
>  	bool "Toumaz Xenif TZ1090 pin control driver"
>  	depends on SOC_TZ1090
> diff --git a/drivers/pinctrl/Makefile b/drivers/pinctrl/Makefile
> index 0475206dd600..e441cd71aedf 100644
> --- a/drivers/pinctrl/Makefile
> +++ b/drivers/pinctrl/Makefile
> @@ -28,6 +28,7 @@ obj-$(CONFIG_PINCTRL_TEGRA30)	+= pinctrl-tegra30.o
>  obj-$(CONFIG_PINCTRL_TEGRA114)	+= pinctrl-tegra114.o
>  obj-$(CONFIG_PINCTRL_TEGRA124)	+= pinctrl-tegra124.o
>  obj-$(CONFIG_PINCTRL_TEGRA_XUSB)	+= pinctrl-tegra-xusb.o
> +obj-$(CONFIG_PINCTRL_TI_IODELAY)	+= pinctrl-ti-iodelay.o

So this objectfile will either be built-in or not be built at all.

>  obj-$(CONFIG_PINCTRL_TZ1090)	+= pinctrl-tz1090.o
>  obj-$(CONFIG_PINCTRL_TZ1090_PDC)	+= pinctrl-tz1090-pdc.o
>  obj-$(CONFIG_PINCTRL_U300)	+= pinctrl-u300.o
> diff --git a/drivers/pinctrl/pinctrl-ti-iodelay.c b/drivers/pinctrl/pinctrl-ti-iodelay.c
> new file mode 100644
> index 000000000000..e4c6e25a781c
> --- /dev/null
> +++ b/drivers/pinctrl/pinctrl-ti-iodelay.c
> @@ -0,0 +1,963 @@
>[...]
> +#include <linux/err.h>
> +#include <linux/init.h>
> +#include <linux/io.h>
> +#include <linux/list.h>
> +#include <linux/module.h>

This is, I think, a bit of a red flag.

> +#include <linux/of_device.h>
> +#include <linux/of.h>
> +#include <linux/pinctrl/pinconf-generic.h>
> +#include <linux/pinctrl/pinconf.h>
> +#include <linux/pinctrl/pinctrl.h>
> +#include <linux/regmap.h>
> +#include <linux/slab.h>

[...]

> +static const struct of_device_id ti_iodelay_of_match[] = {
> +	{.compatible = "ti,dra7-iodelay", .data = &dra7_iodelay_data},
> +	{ /* Hopefully no more.. */ },
> +};
> +MODULE_DEVICE_TABLE(of, ti_iodelay_of_match);
> +
> +static struct platform_driver ti_iodelay_driver = {
> +	.probe = ti_iodelay_probe,
> +	.remove = ti_iodelay_remove,
> +	.driver = {
> +		   .owner = THIS_MODULE,

So THIS_MODULE will, basically, be NULL.

> +		   .name = DRIVER_NAME,
> +		   .of_match_table = ti_iodelay_of_match,
> +		   },
> +};
> +module_platform_driver(ti_iodelay_driver);
> +
> +MODULE_AUTHOR("Texas Instruments, Inc.");
> +MODULE_DESCRIPTION("Pinconf driver for TI's IO Delay module");
> +MODULE_LICENSE("GPL v2");

And these three macros will be preprocessed away.

(Perhaps there are non-modular alternatives to MODULE_DEVICE_TABLE and
module_platform_driver, but I'm not sure how those two macros actually
work.)


Paul Bolle

Re: [PATCH 2/2] pinctrl: Introduce TI IOdelay configuration driver

[Tony Lindgren]

* Paul Bolle <pebolle@tiscali.nl> [150304 14:58]:
> Nishanth Menon schreef op di 03-03-2015 om 18:00 [-0600]:
> > diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig
> > index ee9f44ad7f02..8e463d75fbb2 100644
> > --- a/drivers/pinctrl/Kconfig
> > +++ b/drivers/pinctrl/Kconfig
> > @@ -160,6 +160,17 @@ config PINCTRL_TEGRA_XUSB
> >  	select PINCONF
> >  	select PINMUX
> >  
> > +config PINCTRL_TI_IODELAY
> > +	bool "TI IODelay Module pinconf driver"
> 
> This adds a boolean Kconfig symbol.
> 
> > +	depends on OF
> > +	select PINCONF
> > +	select GENERIC_PINCONF
> > +	select REGMAP_MMIO
> > +	help
> > +	  Say Y here to support Texas Instruments' IODelay pinconf driver.
> > +	  IODelay module is used for the DRA7 SoC family. This driver is in
> > +	  addition to PINCTRL_SINGLE which controls the mux.
> > +
> >  config PINCTRL_TZ1090
> >  	bool "Toumaz Xenif TZ1090 pin control driver"
> >  	depends on SOC_TZ1090
> > diff --git a/drivers/pinctrl/Makefile b/drivers/pinctrl/Makefile
> > index 0475206dd600..e441cd71aedf 100644
> > --- a/drivers/pinctrl/Makefile
> > +++ b/drivers/pinctrl/Makefile
> > @@ -28,6 +28,7 @@ obj-$(CONFIG_PINCTRL_TEGRA30)	+= pinctrl-tegra30.o
> >  obj-$(CONFIG_PINCTRL_TEGRA114)	+= pinctrl-tegra114.o
> >  obj-$(CONFIG_PINCTRL_TEGRA124)	+= pinctrl-tegra124.o
> >  obj-$(CONFIG_PINCTRL_TEGRA_XUSB)	+= pinctrl-tegra-xusb.o
> > +obj-$(CONFIG_PINCTRL_TI_IODELAY)	+= pinctrl-ti-iodelay.o
> 
> So this objectfile will either be built-in or not be built at all.
> 
> >  obj-$(CONFIG_PINCTRL_TZ1090)	+= pinctrl-tz1090.o
> >  obj-$(CONFIG_PINCTRL_TZ1090_PDC)	+= pinctrl-tz1090-pdc.o
> >  obj-$(CONFIG_PINCTRL_U300)	+= pinctrl-u300.o
> > diff --git a/drivers/pinctrl/pinctrl-ti-iodelay.c b/drivers/pinctrl/pinctrl-ti-iodelay.c
> > new file mode 100644
> > index 000000000000..e4c6e25a781c
> > --- /dev/null
> > +++ b/drivers/pinctrl/pinctrl-ti-iodelay.c
> > @@ -0,0 +1,963 @@
> >[...]
> > +#include <linux/err.h>
> > +#include <linux/init.h>
> > +#include <linux/io.h>
> > +#include <linux/list.h>
> > +#include <linux/module.h>
> 
> This is, I think, a bit of a red flag.
> 
> > +#include <linux/of_device.h>
> > +#include <linux/of.h>
> > +#include <linux/pinctrl/pinconf-generic.h>
> > +#include <linux/pinctrl/pinconf.h>
> > +#include <linux/pinctrl/pinctrl.h>
> > +#include <linux/regmap.h>
> > +#include <linux/slab.h>
> 
> [...]
> 
> > +static const struct of_device_id ti_iodelay_of_match[] = {
> > +	{.compatible = "ti,dra7-iodelay", .data = &dra7_iodelay_data},
> > +	{ /* Hopefully no more.. */ },
> > +};
> > +MODULE_DEVICE_TABLE(of, ti_iodelay_of_match);
> > +
> > +static struct platform_driver ti_iodelay_driver = {
> > +	.probe = ti_iodelay_probe,
> > +	.remove = ti_iodelay_remove,
> > +	.driver = {
> > +		   .owner = THIS_MODULE,
> 
> So THIS_MODULE will, basically, be NULL.
> 
> > +		   .name = DRIVER_NAME,
> > +		   .of_match_table = ti_iodelay_of_match,
> > +		   },
> > +};
> > +module_platform_driver(ti_iodelay_driver);
> > +
> > +MODULE_AUTHOR("Texas Instruments, Inc.");
> > +MODULE_DESCRIPTION("Pinconf driver for TI's IO Delay module");
> > +MODULE_LICENSE("GPL v2");
> 
> And these three macros will be preprocessed away.
> 
> (Perhaps there are non-modular alternatives to MODULE_DEVICE_TABLE and
> module_platform_driver, but I'm not sure how those two macros actually
> work.)

This should be just made to work as a regular loadable module.
We already have pinctrl-single for the same platforms working
as a loadable module.

Regards,

Tony

[PATCH 2/2] pinctrl: Introduce TI IOdelay configuration driver

[Tony Lindgren]

* Paul Bolle <pebolle@tiscali.nl> [150304 14:58]:
> Nishanth Menon schreef op di 03-03-2015 om 18:00 [-0600]:
> > diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig
> > index ee9f44ad7f02..8e463d75fbb2 100644
> > --- a/drivers/pinctrl/Kconfig
> > +++ b/drivers/pinctrl/Kconfig
> > @@ -160,6 +160,17 @@ config PINCTRL_TEGRA_XUSB
> >  	select PINCONF
> >  	select PINMUX
> >  
> > +config PINCTRL_TI_IODELAY
> > +	bool "TI IODelay Module pinconf driver"
> 
> This adds a boolean Kconfig symbol.
> 
> > +	depends on OF
> > +	select PINCONF
> > +	select GENERIC_PINCONF
> > +	select REGMAP_MMIO
> > +	help
> > +	  Say Y here to support Texas Instruments' IODelay pinconf driver.
> > +	  IODelay module is used for the DRA7 SoC family. This driver is in
> > +	  addition to PINCTRL_SINGLE which controls the mux.
> > +
> >  config PINCTRL_TZ1090
> >  	bool "Toumaz Xenif TZ1090 pin control driver"
> >  	depends on SOC_TZ1090
> > diff --git a/drivers/pinctrl/Makefile b/drivers/pinctrl/Makefile
> > index 0475206dd600..e441cd71aedf 100644
> > --- a/drivers/pinctrl/Makefile
> > +++ b/drivers/pinctrl/Makefile
> > @@ -28,6 +28,7 @@ obj-$(CONFIG_PINCTRL_TEGRA30)	+= pinctrl-tegra30.o
> >  obj-$(CONFIG_PINCTRL_TEGRA114)	+= pinctrl-tegra114.o
> >  obj-$(CONFIG_PINCTRL_TEGRA124)	+= pinctrl-tegra124.o
> >  obj-$(CONFIG_PINCTRL_TEGRA_XUSB)	+= pinctrl-tegra-xusb.o
> > +obj-$(CONFIG_PINCTRL_TI_IODELAY)	+= pinctrl-ti-iodelay.o
> 
> So this objectfile will either be built-in or not be built at all.
> 
> >  obj-$(CONFIG_PINCTRL_TZ1090)	+= pinctrl-tz1090.o
> >  obj-$(CONFIG_PINCTRL_TZ1090_PDC)	+= pinctrl-tz1090-pdc.o
> >  obj-$(CONFIG_PINCTRL_U300)	+= pinctrl-u300.o
> > diff --git a/drivers/pinctrl/pinctrl-ti-iodelay.c b/drivers/pinctrl/pinctrl-ti-iodelay.c
> > new file mode 100644
> > index 000000000000..e4c6e25a781c
> > --- /dev/null
> > +++ b/drivers/pinctrl/pinctrl-ti-iodelay.c
> > @@ -0,0 +1,963 @@
> >[...]
> > +#include <linux/err.h>
> > +#include <linux/init.h>
> > +#include <linux/io.h>
> > +#include <linux/list.h>
> > +#include <linux/module.h>
> 
> This is, I think, a bit of a red flag.
> 
> > +#include <linux/of_device.h>
> > +#include <linux/of.h>
> > +#include <linux/pinctrl/pinconf-generic.h>
> > +#include <linux/pinctrl/pinconf.h>
> > +#include <linux/pinctrl/pinctrl.h>
> > +#include <linux/regmap.h>
> > +#include <linux/slab.h>
> 
> [...]
> 
> > +static const struct of_device_id ti_iodelay_of_match[] = {
> > +	{.compatible = "ti,dra7-iodelay", .data = &dra7_iodelay_data},
> > +	{ /* Hopefully no more.. */ },
> > +};
> > +MODULE_DEVICE_TABLE(of, ti_iodelay_of_match);
> > +
> > +static struct platform_driver ti_iodelay_driver = {
> > +	.probe = ti_iodelay_probe,
> > +	.remove = ti_iodelay_remove,
> > +	.driver = {
> > +		   .owner = THIS_MODULE,
> 
> So THIS_MODULE will, basically, be NULL.
> 
> > +		   .name = DRIVER_NAME,
> > +		   .of_match_table = ti_iodelay_of_match,
> > +		   },
> > +};
> > +module_platform_driver(ti_iodelay_driver);
> > +
> > +MODULE_AUTHOR("Texas Instruments, Inc.");
> > +MODULE_DESCRIPTION("Pinconf driver for TI's IO Delay module");
> > +MODULE_LICENSE("GPL v2");
> 
> And these three macros will be preprocessed away.
> 
> (Perhaps there are non-modular alternatives to MODULE_DEVICE_TABLE and
> module_platform_driver, but I'm not sure how those two macros actually
> work.)

This should be just made to work as a regular loadable module.
We already have pinctrl-single for the same platforms working
as a loadable module.

Regards,

Tony

Re: [PATCH 2/2] pinctrl: Introduce TI IOdelay configuration driver

[Nishanth Menon]

On 03/04/2015 04:58 PM, Tony Lindgren wrote:
> * Paul Bolle <pebolle@tiscali.nl> [150304 14:58]:
>> Nishanth Menon schreef op di 03-03-2015 om 18:00 [-0600]:
>>> diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig
>>> index ee9f44ad7f02..8e463d75fbb2 100644
>>> --- a/drivers/pinctrl/Kconfig
>>> +++ b/drivers/pinctrl/Kconfig
>>> @@ -160,6 +160,17 @@ config PINCTRL_TEGRA_XUSB
>>>  	select PINCONF
>>>  	select PINMUX
>>>  
>>> +config PINCTRL_TI_IODELAY
>>> +	bool "TI IODelay Module pinconf driver"
>>
>> This adds a boolean Kconfig symbol.

Uggh.. thanks for the review and catching this..

>>
>>> +	depends on OF
>>> +	select PINCONF
>>> +	select GENERIC_PINCONF
>>> +	select REGMAP_MMIO
>>> +	help
>>> +	  Say Y here to support Texas Instruments' IODelay pinconf driver.
>>> +	  IODelay module is used for the DRA7 SoC family. This driver is in
>>> +	  addition to PINCTRL_SINGLE which controls the mux.
>>> +
>>>  config PINCTRL_TZ1090
>>>  	bool "Toumaz Xenif TZ1090 pin control driver"
>>>  	depends on SOC_TZ1090
>>> diff --git a/drivers/pinctrl/Makefile b/drivers/pinctrl/Makefile
>>> index 0475206dd600..e441cd71aedf 100644
>>> --- a/drivers/pinctrl/Makefile
>>> +++ b/drivers/pinctrl/Makefile
>>> @@ -28,6 +28,7 @@ obj-$(CONFIG_PINCTRL_TEGRA30)	+= pinctrl-tegra30.o
>>>  obj-$(CONFIG_PINCTRL_TEGRA114)	+= pinctrl-tegra114.o
>>>  obj-$(CONFIG_PINCTRL_TEGRA124)	+= pinctrl-tegra124.o
>>>  obj-$(CONFIG_PINCTRL_TEGRA_XUSB)	+= pinctrl-tegra-xusb.o
>>> +obj-$(CONFIG_PINCTRL_TI_IODELAY)	+= pinctrl-ti-iodelay.o
>>
>> So this objectfile will either be built-in or not be built at all.
>>
>>>  obj-$(CONFIG_PINCTRL_TZ1090)	+= pinctrl-tz1090.o
>>>  obj-$(CONFIG_PINCTRL_TZ1090_PDC)	+= pinctrl-tz1090-pdc.o
>>>  obj-$(CONFIG_PINCTRL_U300)	+= pinctrl-u300.o
>>> diff --git a/drivers/pinctrl/pinctrl-ti-iodelay.c b/drivers/pinctrl/pinctrl-ti-iodelay.c
>>> new file mode 100644
>>> index 000000000000..e4c6e25a781c
>>> --- /dev/null
>>> +++ b/drivers/pinctrl/pinctrl-ti-iodelay.c
>>> @@ -0,0 +1,963 @@
>>> [...]
>>> +#include <linux/err.h>
>>> +#include <linux/init.h>
>>> +#include <linux/io.h>
>>> +#include <linux/list.h>
>>> +#include <linux/module.h>
>>
>> This is, I think, a bit of a red flag.
>>
>>> +#include <linux/of_device.h>
>>> +#include <linux/of.h>
>>> +#include <linux/pinctrl/pinconf-generic.h>
>>> +#include <linux/pinctrl/pinconf.h>
>>> +#include <linux/pinctrl/pinctrl.h>
>>> +#include <linux/regmap.h>
>>> +#include <linux/slab.h>
>>
>> [...]
>>
>>> +static const struct of_device_id ti_iodelay_of_match[] = {
>>> +	{.compatible = "ti,dra7-iodelay", .data = &dra7_iodelay_data},
>>> +	{ /* Hopefully no more.. */ },
>>> +};
>>> +MODULE_DEVICE_TABLE(of, ti_iodelay_of_match);
>>> +
>>> +static struct platform_driver ti_iodelay_driver = {
>>> +	.probe = ti_iodelay_probe,
>>> +	.remove = ti_iodelay_remove,
>>> +	.driver = {
>>> +		   .owner = THIS_MODULE,
>>
>> So THIS_MODULE will, basically, be NULL.
>>
>>> +		   .name = DRIVER_NAME,
>>> +		   .of_match_table = ti_iodelay_of_match,
>>> +		   },
>>> +};
>>> +module_platform_driver(ti_iodelay_driver);
>>> +
>>> +MODULE_AUTHOR("Texas Instruments, Inc.");
>>> +MODULE_DESCRIPTION("Pinconf driver for TI's IO Delay module");
>>> +MODULE_LICENSE("GPL v2");
>>
>> And these three macros will be preprocessed away.
>>
>> (Perhaps there are non-modular alternatives to MODULE_DEVICE_TABLE and
>> module_platform_driver, but I'm not sure how those two macros actually
>> work.)
> 
> This should be just made to work as a regular loadable module.
> We already have pinctrl-single for the same platforms working
> as a loadable module.
> 
Yes, indeed. this can easily be fixed. my bad. will convert this to a
module in the next rev.

I will wait a week before reposting next rev to see if there are
improvements necessary in other areas - specifically in the way
pinconf is being used and if there are any binding related comments.

Will be great to hear any feedback on the same as well.


-- 
Regards,
Nishanth Menon

[PATCH 2/2] pinctrl: Introduce TI IOdelay configuration driver

[Nishanth Menon]

On 03/04/2015 04:58 PM, Tony Lindgren wrote:
> * Paul Bolle <pebolle@tiscali.nl> [150304 14:58]:
>> Nishanth Menon schreef op di 03-03-2015 om 18:00 [-0600]:
>>> diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig
>>> index ee9f44ad7f02..8e463d75fbb2 100644
>>> --- a/drivers/pinctrl/Kconfig
>>> +++ b/drivers/pinctrl/Kconfig
>>> @@ -160,6 +160,17 @@ config PINCTRL_TEGRA_XUSB
>>>  	select PINCONF
>>>  	select PINMUX
>>>  
>>> +config PINCTRL_TI_IODELAY
>>> +	bool "TI IODelay Module pinconf driver"
>>
>> This adds a boolean Kconfig symbol.

Uggh.. thanks for the review and catching this..

>>
>>> +	depends on OF
>>> +	select PINCONF
>>> +	select GENERIC_PINCONF
>>> +	select REGMAP_MMIO
>>> +	help
>>> +	  Say Y here to support Texas Instruments' IODelay pinconf driver.
>>> +	  IODelay module is used for the DRA7 SoC family. This driver is in
>>> +	  addition to PINCTRL_SINGLE which controls the mux.
>>> +
>>>  config PINCTRL_TZ1090
>>>  	bool "Toumaz Xenif TZ1090 pin control driver"
>>>  	depends on SOC_TZ1090
>>> diff --git a/drivers/pinctrl/Makefile b/drivers/pinctrl/Makefile
>>> index 0475206dd600..e441cd71aedf 100644
>>> --- a/drivers/pinctrl/Makefile
>>> +++ b/drivers/pinctrl/Makefile
>>> @@ -28,6 +28,7 @@ obj-$(CONFIG_PINCTRL_TEGRA30)	+= pinctrl-tegra30.o
>>>  obj-$(CONFIG_PINCTRL_TEGRA114)	+= pinctrl-tegra114.o
>>>  obj-$(CONFIG_PINCTRL_TEGRA124)	+= pinctrl-tegra124.o
>>>  obj-$(CONFIG_PINCTRL_TEGRA_XUSB)	+= pinctrl-tegra-xusb.o
>>> +obj-$(CONFIG_PINCTRL_TI_IODELAY)	+= pinctrl-ti-iodelay.o
>>
>> So this objectfile will either be built-in or not be built at all.
>>
>>>  obj-$(CONFIG_PINCTRL_TZ1090)	+= pinctrl-tz1090.o
>>>  obj-$(CONFIG_PINCTRL_TZ1090_PDC)	+= pinctrl-tz1090-pdc.o
>>>  obj-$(CONFIG_PINCTRL_U300)	+= pinctrl-u300.o
>>> diff --git a/drivers/pinctrl/pinctrl-ti-iodelay.c b/drivers/pinctrl/pinctrl-ti-iodelay.c
>>> new file mode 100644
>>> index 000000000000..e4c6e25a781c
>>> --- /dev/null
>>> +++ b/drivers/pinctrl/pinctrl-ti-iodelay.c
>>> @@ -0,0 +1,963 @@
>>> [...]
>>> +#include <linux/err.h>
>>> +#include <linux/init.h>
>>> +#include <linux/io.h>
>>> +#include <linux/list.h>
>>> +#include <linux/module.h>
>>
>> This is, I think, a bit of a red flag.
>>
>>> +#include <linux/of_device.h>
>>> +#include <linux/of.h>
>>> +#include <linux/pinctrl/pinconf-generic.h>
>>> +#include <linux/pinctrl/pinconf.h>
>>> +#include <linux/pinctrl/pinctrl.h>
>>> +#include <linux/regmap.h>
>>> +#include <linux/slab.h>
>>
>> [...]
>>
>>> +static const struct of_device_id ti_iodelay_of_match[] = {
>>> +	{.compatible = "ti,dra7-iodelay", .data = &dra7_iodelay_data},
>>> +	{ /* Hopefully no more.. */ },
>>> +};
>>> +MODULE_DEVICE_TABLE(of, ti_iodelay_of_match);
>>> +
>>> +static struct platform_driver ti_iodelay_driver = {
>>> +	.probe = ti_iodelay_probe,
>>> +	.remove = ti_iodelay_remove,
>>> +	.driver = {
>>> +		   .owner = THIS_MODULE,
>>
>> So THIS_MODULE will, basically, be NULL.
>>
>>> +		   .name = DRIVER_NAME,
>>> +		   .of_match_table = ti_iodelay_of_match,
>>> +		   },
>>> +};
>>> +module_platform_driver(ti_iodelay_driver);
>>> +
>>> +MODULE_AUTHOR("Texas Instruments, Inc.");
>>> +MODULE_DESCRIPTION("Pinconf driver for TI's IO Delay module");
>>> +MODULE_LICENSE("GPL v2");
>>
>> And these three macros will be preprocessed away.
>>
>> (Perhaps there are non-modular alternatives to MODULE_DEVICE_TABLE and
>> module_platform_driver, but I'm not sure how those two macros actually
>> work.)
> 
> This should be just made to work as a regular loadable module.
> We already have pinctrl-single for the same platforms working
> as a loadable module.
> 
Yes, indeed. this can easily be fixed. my bad. will convert this to a
module in the next rev.

I will wait a week before reposting next rev to see if there are
improvements necessary in other areas - specifically in the way
pinconf is being used and if there are any binding related comments.

Will be great to hear any feedback on the same as well.


-- 
Regards,
Nishanth Menon

Re: [PATCH 2/2] pinctrl: Introduce TI IOdelay configuration driver

[Nishanth Menon]

On 03/04/2015 04:58 PM, Tony Lindgren wrote:
> * Paul Bolle <pebolle@tiscali.nl> [150304 14:58]:
>> Nishanth Menon schreef op di 03-03-2015 om 18:00 [-0600]:
>>> diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig
>>> index ee9f44ad7f02..8e463d75fbb2 100644
>>> --- a/drivers/pinctrl/Kconfig
>>> +++ b/drivers/pinctrl/Kconfig
>>> @@ -160,6 +160,17 @@ config PINCTRL_TEGRA_XUSB
>>>  	select PINCONF
>>>  	select PINMUX
>>>  
>>> +config PINCTRL_TI_IODELAY
>>> +	bool "TI IODelay Module pinconf driver"
>>
>> This adds a boolean Kconfig symbol.

Uggh.. thanks for the review and catching this..

>>
>>> +	depends on OF
>>> +	select PINCONF
>>> +	select GENERIC_PINCONF
>>> +	select REGMAP_MMIO
>>> +	help
>>> +	  Say Y here to support Texas Instruments' IODelay pinconf driver.
>>> +	  IODelay module is used for the DRA7 SoC family. This driver is in
>>> +	  addition to PINCTRL_SINGLE which controls the mux.
>>> +
>>>  config PINCTRL_TZ1090
>>>  	bool "Toumaz Xenif TZ1090 pin control driver"
>>>  	depends on SOC_TZ1090
>>> diff --git a/drivers/pinctrl/Makefile b/drivers/pinctrl/Makefile
>>> index 0475206dd600..e441cd71aedf 100644
>>> --- a/drivers/pinctrl/Makefile
>>> +++ b/drivers/pinctrl/Makefile
>>> @@ -28,6 +28,7 @@ obj-$(CONFIG_PINCTRL_TEGRA30)	+= pinctrl-tegra30.o
>>>  obj-$(CONFIG_PINCTRL_TEGRA114)	+= pinctrl-tegra114.o
>>>  obj-$(CONFIG_PINCTRL_TEGRA124)	+= pinctrl-tegra124.o
>>>  obj-$(CONFIG_PINCTRL_TEGRA_XUSB)	+= pinctrl-tegra-xusb.o
>>> +obj-$(CONFIG_PINCTRL_TI_IODELAY)	+= pinctrl-ti-iodelay.o
>>
>> So this objectfile will either be built-in or not be built at all.
>>
>>>  obj-$(CONFIG_PINCTRL_TZ1090)	+= pinctrl-tz1090.o
>>>  obj-$(CONFIG_PINCTRL_TZ1090_PDC)	+= pinctrl-tz1090-pdc.o
>>>  obj-$(CONFIG_PINCTRL_U300)	+= pinctrl-u300.o
>>> diff --git a/drivers/pinctrl/pinctrl-ti-iodelay.c b/drivers/pinctrl/pinctrl-ti-iodelay.c
>>> new file mode 100644
>>> index 000000000000..e4c6e25a781c
>>> --- /dev/null
>>> +++ b/drivers/pinctrl/pinctrl-ti-iodelay.c
>>> @@ -0,0 +1,963 @@
>>> [...]
>>> +#include <linux/err.h>
>>> +#include <linux/init.h>
>>> +#include <linux/io.h>
>>> +#include <linux/list.h>
>>> +#include <linux/module.h>
>>
>> This is, I think, a bit of a red flag.
>>
>>> +#include <linux/of_device.h>
>>> +#include <linux/of.h>
>>> +#include <linux/pinctrl/pinconf-generic.h>
>>> +#include <linux/pinctrl/pinconf.h>
>>> +#include <linux/pinctrl/pinctrl.h>
>>> +#include <linux/regmap.h>
>>> +#include <linux/slab.h>
>>
>> [...]
>>
>>> +static const struct of_device_id ti_iodelay_of_match[] = {
>>> +	{.compatible = "ti,dra7-iodelay", .data = &dra7_iodelay_data},
>>> +	{ /* Hopefully no more.. */ },
>>> +};
>>> +MODULE_DEVICE_TABLE(of, ti_iodelay_of_match);
>>> +
>>> +static struct platform_driver ti_iodelay_driver = {
>>> +	.probe = ti_iodelay_probe,
>>> +	.remove = ti_iodelay_remove,
>>> +	.driver = {
>>> +		   .owner = THIS_MODULE,
>>
>> So THIS_MODULE will, basically, be NULL.
>>
>>> +		   .name = DRIVER_NAME,
>>> +		   .of_match_table = ti_iodelay_of_match,
>>> +		   },
>>> +};
>>> +module_platform_driver(ti_iodelay_driver);
>>> +
>>> +MODULE_AUTHOR("Texas Instruments, Inc.");
>>> +MODULE_DESCRIPTION("Pinconf driver for TI's IO Delay module");
>>> +MODULE_LICENSE("GPL v2");
>>
>> And these three macros will be preprocessed away.
>>
>> (Perhaps there are non-modular alternatives to MODULE_DEVICE_TABLE and
>> module_platform_driver, but I'm not sure how those two macros actually
>> work.)
> 
> This should be just made to work as a regular loadable module.
> We already have pinctrl-single for the same platforms working
> as a loadable module.
> 
Yes, indeed. this can easily be fixed. my bad. will convert this to a
module in the next rev.

I will wait a week before reposting next rev to see if there are
improvements necessary in other areas - specifically in the way
pinconf is being used and if there are any binding related comments.

Will be great to hear any feedback on the same as well.


-- 
Regards,
Nishanth Menon

Re: [PATCH 2/2] pinctrl: Introduce TI IOdelay configuration driver

[Linus Walleij]

On Wed, Mar 4, 2015 at 1:00 AM, Nishanth Menon <nm@ti.com> wrote:

> SoC family such as DRA7 family of processors have, in addition
> to the regular muxing of pins (as done by pinctrl-single), an
> additional hardware module called IODelay which is also expected to be
> configured. This "IODelay" module has it's own register space that is
> independent of the control module.
>
> It is advocated strongly in TI's official documentation considering
> the existing design of the DRA7 family of processors during mux or
> IODelay reconfiguration, there is a potential for a significant glitch
> which may cause functional impairment to certain hardware. It is
> hence recommended to do as little of muxing as absolutely necessary
> without I/O isolation (which can only be done in initial stages of
> bootloader).
>
> NOTE: with the system wide I/O isolation scheme present in DRA7 SoC
> family, it is not reasonable to do stop all I/O operations for every
> such pad configuration scheme. So, we will let it glitch when used in
> this mode.
>
> Even with the above limitation, certain functionality such as MMC has
> mandatory need for IODelay reconfiguration requirements, depending on
> speed of transfer. In these cases, with careful examination of usecase
> involved, the expected glitch can be controlled such that it does not
> impact functionality.
>
> In short, IODelay module support as a padconf driver being introduced
> here is not expected to do SoC wide I/O Isolation and is meant for
> a limited subset of IODelay configuration requirements that need to
> be dynamic and whose glitchy behavior will not cause functionality
> failure for that interface.
>
> Signed-off-by: Nishanth Menon <nm@ti.com>
> Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>

Pending the conclusion of my remark on the bindings that this
should use the generic pin config bindings... here are some
"normal" review comments.

> +config PINCTRL_TI_IODELAY
> +       bool "TI IODelay Module pinconf driver"
> +       depends on OF
> +       select PINCONF
> +       select GENERIC_PINCONF
> +       select REGMAP_MMIO
> +       help
> +         Say Y here to support Texas Instruments' IODelay pinconf driver.
> +         IODelay module is used for the DRA7 SoC family. This driver is in
> +         addition to PINCTRL_SINGLE which controls the mux.

If the driver is "in addition to PINCTRL_SINGLE", then it
should depend on it.

> +/* Should I change this? Abuse? */
> +#define IODELAY_MUX_PINS_NAME          "pinctrl-single,pins"

Yeah this is abuse and is why you should use the generic
bindings with just "pins" instead, and use the generic pinconf
parameters to set them up.

> + * struct ti_iodelay_conf_vals - Description of each configuration parameters.
> + * @offset:    Configuration register offset
> + * @a_delay:   Agnostic Delay (in ps)
> + * @g_delay:   Gnostic Delay (in ps)
> + */
> +struct ti_iodelay_conf_vals {
> +       u16 offset;
> +       u16 a_delay;
> +       u16 g_delay;
> +};

So I don't think it's a good idea to get the register offset from
the device tree. The driver should know these.

> +/**
> + * struct ti_iodelay_reg_values - Computed io_reg configuration values (see TRM)
> + * @coarse_ref_count:  Coarse reference count
> + * @coarse_delay_count:        Coarse delay count
> + * @fine_ref_count:    Fine reference count
> + * @fine_delay_count:  Fine Delay count
> + * @ref_clk_period:    Reference Clock period
> + * @cdpe:              Coarse delay parameter
> + * @fdpe:              Fine delay parameter
> + */
> +struct ti_iodelay_reg_values {
> +       u16 coarse_ref_count;

If you're doing reference counting, use kref.
<linux/kref.h>

> +       u16 coarse_delay_count;
> +
> +       u16 fine_ref_count;

Dito.

> +       u16 fine_delay_count;
> +
> +       u16 ref_clk_period;
> +
> +       u32 cdpe;
> +       u32 fdpe;
> +};


> +/**
> + * struct ti_iodelay_pin_name - name of the pins
> + * @name: name
> + */
> +struct ti_iodelay_pin_name {
> +       char name[IODELAY_REG_NAME_LEN];
> +};

What is this? The pin control subsystem already has a struct
for naming pins. struct pinctrl_pin_desc.

Are you reimplementing core functionality?

The generic pin config reference pins by name, and since you
obviously like to encode these into you data you can just
as well use that method for this too.

Again I think this is a side effect from using the pinctrl-single
concepts, if you think of this as some other pinctrl driver
I think this will fall out nicely.

> +/**
> + * struct ti_iodelay_device - Represents information for a IOdelay instance
> + * @dev: device pointer
> + * @reg_base: Remapped virtual address
> + * @regmap: Regmap for this IOdelay instance
> + * @pctl: Pinctrl device
> + * @desc: pinctrl descriptor for pctl
> + * @pa: pinctrl pin wise description
> + * @names: names of the pins
> + * @groups: list of pinconf groups for iodelay instance
> + * @ngroups: number of groups in the list
> + * @mutex: mutex to protect group list modification
> + * @reg_data: Register definition data for the IODelay instance
> + * @reg_init_conf_values: Initial configuration values.
> + */
> +struct ti_iodelay_device {
> +       struct device *dev;
> +       void __iomem *reg_base;
> +       struct regmap *regmap;
> +
> +       struct pinctrl_dev *pctl;
> +       struct pinctrl_desc desc;
> +       struct pinctrl_pin_desc *pa;
> +       struct ti_iodelay_pin_name *names;

Unhappy about that. pinctrl_desc contains
struct pinctrl_pin_desc const *pins; !

> +
> +       struct list_head groups;
> +       int ngroups;
> +       struct mutex mutex; /* list protection */

Why is this needed? Usually the pin control core
serialize calls into the drivers. Care to explain? Have
the potential race really triggered?

> +static inline u32 ti_iodelay_compute_dpe(u16 period, u16 ref, u16 delay,
> +                                        u16 delay_m)
> +{
> +       u64 m, d;
> +
> +       /* Handle overflow conditions */
> +       m = 10 * (u64)period * (u64)ref;
> +       d = 2 * (u64)delay * (u64)delay_m;
> +
> +       /* Truncate result back to 32 bits */
> +       return div64_u64(m, d);
> +}

Serious business ...

> +/**
> + * ti_iodelay_pinconf_set() - Configure the pin configuration
> + * @iod:       IODelay device
> + * @val:       Configuration value
> + *
> + * Update the configuration register as per TRM and lockup once done.
> + * *IMPORTANT NOTE* SoC TRM does recommend doing iodelay programmation only
> + * while in Isolation. But, then, isolation also implies that every pin
> + * on the SoC(including DDR) will be isolated out. The only benefit being
> + * a glitchless configuration, However, the intent of this driver is purely
> + * to support a "glitchy" configuration where applicable.
> + *
> + * Return: 0 in case of success, else appropriate error value
> + */
> +static int ti_iodelay_pinconf_set(struct ti_iodelay_device *iod,
> +                                 struct ti_iodelay_conf_vals *val)
> +{
> +       const struct ti_iodelay_reg_data *reg = iod->reg_data;
> +       struct ti_iodelay_reg_values *ival = &iod->reg_init_conf_values;
> +       struct device *dev = iod->dev;
> +       u32 g_delay_coarse, g_delay_fine;
> +       u32 a_delay_coarse, a_delay_fine;
> +       u32 c_elements, f_elements;
> +       u32 total_delay;
> +       u32 reg_mask, reg_val, tmp_val;
> +       int r;
> +
> +       /* NOTE: Truncation is expected in all division below */
> +       g_delay_coarse = val->g_delay / 920;
> +       g_delay_fine = ((val->g_delay % 920) * 10) / 60;
> +
> +       a_delay_coarse = val->a_delay / ival->cdpe;
> +       a_delay_fine = ((val->a_delay % ival->cdpe) * 10) / ival->fdpe;
> +
> +       c_elements = g_delay_coarse + a_delay_coarse;
> +       f_elements = (g_delay_fine + a_delay_fine) / 10;
> +
> +       if (f_elements > 22) {
> +               total_delay = c_elements * ival->cdpe + f_elements * ival->fdpe;
> +               c_elements = total_delay / ival->cdpe;
> +               f_elements = (total_delay % ival->cdpe) / ival->fdpe;
> +       }
> +
> +       reg_mask = reg->signature_mask;
> +       reg_val = reg->signature_value << __ffs(reg->signature_mask);
> +
> +       reg_mask |= reg->binary_data_coarse_mask;
> +       tmp_val = c_elements << __ffs(reg->binary_data_coarse_mask);
> +       if (tmp_val & ~reg->binary_data_coarse_mask) {
> +               dev_err(dev, "Masking overflow of coarse elements %08x\n",
> +                       tmp_val);
> +               tmp_val &= reg->binary_data_coarse_mask;
> +       }
> +       reg_val |= tmp_val;
> +
> +       reg_mask |= reg->binary_data_fine_mask;
> +       tmp_val = f_elements << __ffs(reg->binary_data_fine_mask);
> +       if (tmp_val & ~reg->binary_data_fine_mask) {
> +               dev_err(dev, "Masking overflow of fine elements %08x\n",
> +                       tmp_val);
> +               tmp_val &= reg->binary_data_fine_mask;
> +       }
> +       reg_val |= tmp_val;
> +
> +       /* Write with lock value - we DONOT want h/w updates */
> +       reg_mask |= reg->lock_mask;
> +       reg_val |= reg->lock_val << __ffs(reg->lock_mask);
> +       r = regmap_update_bits(iod->regmap, val->offset, reg_mask, reg_val);
> +
> +       dev_dbg(dev, "Set reg 0x%x Delay(a=%d g=%d), Elements(C=%d F=%d)0x%x\n",
> +               val->offset, val->a_delay, val->g_delay, c_elements,
> +               f_elements, reg_val);
> +
> +       return r;
> +}

Looking at this terse thing I think it's obviously easier to use
a more verbose device tree description with

drive-delay = <some SI unit>;


> +       /* unlock the IOdelay region */
> +       r = regmap_update_bits(iod->regmap, reg->reg_global_lock_offset,
> +                              reg->global_lock_mask, reg->global_unlock_val);
> +       if (r)
> +               return r;
> +
> +       /* Read up Recalibration sequence done by bootloader */
> +       r = regmap_read(iod->regmap, reg->reg_refclk_offset, &val);
> +       if (r)
> +               return r;
> +       ival->ref_clk_period = ti_iodelay_extract(val, reg->refclk_period_mask);
> +       dev_dbg(dev, "refclk_period=0x%04x\n", ival->ref_clk_period);

That sounds hightec. So the bootloader calibrates the delays
and  computes the refclock period? So is that sime PLL or something?

> +       r = regmap_read(iod->regmap, reg->reg_coarse_offset, &val);
> +       if (r)
> +               return r;
> +       ival->coarse_ref_count =
> +           ti_iodelay_extract(val, reg->coarse_ref_count_mask);
> +       ival->coarse_delay_count =
> +           ti_iodelay_extract(val, reg->coarse_delay_count_mask);
> +       if (!ival->coarse_delay_count) {
> +               dev_err(dev, "Invalid Coarse delay count (0) (reg=0x%08x)\n",
> +                       val);
> +               return -EINVAL;
> +       }
> +       ival->cdpe = ti_iodelay_compute_dpe(ival->ref_clk_period,
> +                                           ival->coarse_ref_count,
> +                                           ival->coarse_delay_count, 88);

88? What does that mean... This should be #defined I think.

> +static int ti_iodelay_dt_node_to_map(struct pinctrl_dev *pctldev,
> +                                    struct device_node *np,
> +                                    struct pinctrl_map **map,
> +                                    unsigned *num_maps)

If you use the generic bindings this quite complex parsing and
everything associated with it goes away into the core.

> +static void ti_iodelay_dt_free_map(struct pinctrl_dev *pctldev,
> +                                  struct pinctrl_map *map, unsigned num_maps)

Dito.

BTW even if you proceed this way I suspect these are verbatim
copies from pinctrl-single so they shold obviouslyt be abstracted
out as library functions in that case.

> +/**
> + * ti_iodelay_pinctrl_get_group_pins() - get group pins
> + * @pctldev:   pinctrl device representing IODelay device
> + * @gselector: Group selector
> + * @pins:      pointer to the pins
> + * @npins:     number of pins
> + *
> + * Dummy implementation since we do not track pins, we track configurations
> + * Forced by pinctrl's pinctrl_check_ops()
> + *
> + * Return: -EINVAL
> + */
> +static int ti_iodelay_pinctrl_get_group_pins(struct pinctrl_dev *pctldev,
> +                                            unsigned gselector,
> +                                            const unsigned **pins,
> +                                            unsigned *npins)
> +{
> +       /* Dummy implementation - we dont do pin mux */
> +       return -EINVAL;
> +}

This is not about muxing. It is about enumerating the pins in the
group that will be affected by the setting, which is something you
will want to do when using the generic bindings.

> +       group = ti_iodelay_get_group(iod, gselector);

And this seems to be your re-implementation of exactly that pin control
core functionality. Which again should be shared with pinctrl-single if
you anyway go down this path.

I'll halt review here pending discussion on the bindings & stuff.

Yours,
Linus Walleij

[PATCH 2/2] pinctrl: Introduce TI IOdelay configuration driver

[Linus Walleij]

On Wed, Mar 4, 2015 at 1:00 AM, Nishanth Menon <nm@ti.com> wrote:

> SoC family such as DRA7 family of processors have, in addition
> to the regular muxing of pins (as done by pinctrl-single), an
> additional hardware module called IODelay which is also expected to be
> configured. This "IODelay" module has it's own register space that is
> independent of the control module.
>
> It is advocated strongly in TI's official documentation considering
> the existing design of the DRA7 family of processors during mux or
> IODelay reconfiguration, there is a potential for a significant glitch
> which may cause functional impairment to certain hardware. It is
> hence recommended to do as little of muxing as absolutely necessary
> without I/O isolation (which can only be done in initial stages of
> bootloader).
>
> NOTE: with the system wide I/O isolation scheme present in DRA7 SoC
> family, it is not reasonable to do stop all I/O operations for every
> such pad configuration scheme. So, we will let it glitch when used in
> this mode.
>
> Even with the above limitation, certain functionality such as MMC has
> mandatory need for IODelay reconfiguration requirements, depending on
> speed of transfer. In these cases, with careful examination of usecase
> involved, the expected glitch can be controlled such that it does not
> impact functionality.
>
> In short, IODelay module support as a padconf driver being introduced
> here is not expected to do SoC wide I/O Isolation and is meant for
> a limited subset of IODelay configuration requirements that need to
> be dynamic and whose glitchy behavior will not cause functionality
> failure for that interface.
>
> Signed-off-by: Nishanth Menon <nm@ti.com>
> Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>

Pending the conclusion of my remark on the bindings that this
should use the generic pin config bindings... here are some
"normal" review comments.

> +config PINCTRL_TI_IODELAY
> +       bool "TI IODelay Module pinconf driver"
> +       depends on OF
> +       select PINCONF
> +       select GENERIC_PINCONF
> +       select REGMAP_MMIO
> +       help
> +         Say Y here to support Texas Instruments' IODelay pinconf driver.
> +         IODelay module is used for the DRA7 SoC family. This driver is in
> +         addition to PINCTRL_SINGLE which controls the mux.

If the driver is "in addition to PINCTRL_SINGLE", then it
should depend on it.

> +/* Should I change this? Abuse? */
> +#define IODELAY_MUX_PINS_NAME          "pinctrl-single,pins"

Yeah this is abuse and is why you should use the generic
bindings with just "pins" instead, and use the generic pinconf
parameters to set them up.

> + * struct ti_iodelay_conf_vals - Description of each configuration parameters.
> + * @offset:    Configuration register offset
> + * @a_delay:   Agnostic Delay (in ps)
> + * @g_delay:   Gnostic Delay (in ps)
> + */
> +struct ti_iodelay_conf_vals {
> +       u16 offset;
> +       u16 a_delay;
> +       u16 g_delay;
> +};

So I don't think it's a good idea to get the register offset from
the device tree. The driver should know these.

> +/**
> + * struct ti_iodelay_reg_values - Computed io_reg configuration values (see TRM)
> + * @coarse_ref_count:  Coarse reference count
> + * @coarse_delay_count:        Coarse delay count
> + * @fine_ref_count:    Fine reference count
> + * @fine_delay_count:  Fine Delay count
> + * @ref_clk_period:    Reference Clock period
> + * @cdpe:              Coarse delay parameter
> + * @fdpe:              Fine delay parameter
> + */
> +struct ti_iodelay_reg_values {
> +       u16 coarse_ref_count;

If you're doing reference counting, use kref.
<linux/kref.h>

> +       u16 coarse_delay_count;
> +
> +       u16 fine_ref_count;

Dito.

> +       u16 fine_delay_count;
> +
> +       u16 ref_clk_period;
> +
> +       u32 cdpe;
> +       u32 fdpe;
> +};


> +/**
> + * struct ti_iodelay_pin_name - name of the pins
> + * @name: name
> + */
> +struct ti_iodelay_pin_name {
> +       char name[IODELAY_REG_NAME_LEN];
> +};

What is this? The pin control subsystem already has a struct
for naming pins. struct pinctrl_pin_desc.

Are you reimplementing core functionality?

The generic pin config reference pins by name, and since you
obviously like to encode these into you data you can just
as well use that method for this too.

Again I think this is a side effect from using the pinctrl-single
concepts, if you think of this as some other pinctrl driver
I think this will fall out nicely.

> +/**
> + * struct ti_iodelay_device - Represents information for a IOdelay instance
> + * @dev: device pointer
> + * @reg_base: Remapped virtual address
> + * @regmap: Regmap for this IOdelay instance
> + * @pctl: Pinctrl device
> + * @desc: pinctrl descriptor for pctl
> + * @pa: pinctrl pin wise description
> + * @names: names of the pins
> + * @groups: list of pinconf groups for iodelay instance
> + * @ngroups: number of groups in the list
> + * @mutex: mutex to protect group list modification
> + * @reg_data: Register definition data for the IODelay instance
> + * @reg_init_conf_values: Initial configuration values.
> + */
> +struct ti_iodelay_device {
> +       struct device *dev;
> +       void __iomem *reg_base;
> +       struct regmap *regmap;
> +
> +       struct pinctrl_dev *pctl;
> +       struct pinctrl_desc desc;
> +       struct pinctrl_pin_desc *pa;
> +       struct ti_iodelay_pin_name *names;

Unhappy about that. pinctrl_desc contains
struct pinctrl_pin_desc const *pins; !

> +
> +       struct list_head groups;
> +       int ngroups;
> +       struct mutex mutex; /* list protection */

Why is this needed? Usually the pin control core
serialize calls into the drivers. Care to explain? Have
the potential race really triggered?

> +static inline u32 ti_iodelay_compute_dpe(u16 period, u16 ref, u16 delay,
> +                                        u16 delay_m)
> +{
> +       u64 m, d;
> +
> +       /* Handle overflow conditions */
> +       m = 10 * (u64)period * (u64)ref;
> +       d = 2 * (u64)delay * (u64)delay_m;
> +
> +       /* Truncate result back to 32 bits */
> +       return div64_u64(m, d);
> +}

Serious business ...

> +/**
> + * ti_iodelay_pinconf_set() - Configure the pin configuration
> + * @iod:       IODelay device
> + * @val:       Configuration value
> + *
> + * Update the configuration register as per TRM and lockup once done.
> + * *IMPORTANT NOTE* SoC TRM does recommend doing iodelay programmation only
> + * while in Isolation. But, then, isolation also implies that every pin
> + * on the SoC(including DDR) will be isolated out. The only benefit being
> + * a glitchless configuration, However, the intent of this driver is purely
> + * to support a "glitchy" configuration where applicable.
> + *
> + * Return: 0 in case of success, else appropriate error value
> + */
> +static int ti_iodelay_pinconf_set(struct ti_iodelay_device *iod,
> +                                 struct ti_iodelay_conf_vals *val)
> +{
> +       const struct ti_iodelay_reg_data *reg = iod->reg_data;
> +       struct ti_iodelay_reg_values *ival = &iod->reg_init_conf_values;
> +       struct device *dev = iod->dev;
> +       u32 g_delay_coarse, g_delay_fine;
> +       u32 a_delay_coarse, a_delay_fine;
> +       u32 c_elements, f_elements;
> +       u32 total_delay;
> +       u32 reg_mask, reg_val, tmp_val;
> +       int r;
> +
> +       /* NOTE: Truncation is expected in all division below */
> +       g_delay_coarse = val->g_delay / 920;
> +       g_delay_fine = ((val->g_delay % 920) * 10) / 60;
> +
> +       a_delay_coarse = val->a_delay / ival->cdpe;
> +       a_delay_fine = ((val->a_delay % ival->cdpe) * 10) / ival->fdpe;
> +
> +       c_elements = g_delay_coarse + a_delay_coarse;
> +       f_elements = (g_delay_fine + a_delay_fine) / 10;
> +
> +       if (f_elements > 22) {
> +               total_delay = c_elements * ival->cdpe + f_elements * ival->fdpe;
> +               c_elements = total_delay / ival->cdpe;
> +               f_elements = (total_delay % ival->cdpe) / ival->fdpe;
> +       }
> +
> +       reg_mask = reg->signature_mask;
> +       reg_val = reg->signature_value << __ffs(reg->signature_mask);
> +
> +       reg_mask |= reg->binary_data_coarse_mask;
> +       tmp_val = c_elements << __ffs(reg->binary_data_coarse_mask);
> +       if (tmp_val & ~reg->binary_data_coarse_mask) {
> +               dev_err(dev, "Masking overflow of coarse elements %08x\n",
> +                       tmp_val);
> +               tmp_val &= reg->binary_data_coarse_mask;
> +       }
> +       reg_val |= tmp_val;
> +
> +       reg_mask |= reg->binary_data_fine_mask;
> +       tmp_val = f_elements << __ffs(reg->binary_data_fine_mask);
> +       if (tmp_val & ~reg->binary_data_fine_mask) {
> +               dev_err(dev, "Masking overflow of fine elements %08x\n",
> +                       tmp_val);
> +               tmp_val &= reg->binary_data_fine_mask;
> +       }
> +       reg_val |= tmp_val;
> +
> +       /* Write with lock value - we DONOT want h/w updates */
> +       reg_mask |= reg->lock_mask;
> +       reg_val |= reg->lock_val << __ffs(reg->lock_mask);
> +       r = regmap_update_bits(iod->regmap, val->offset, reg_mask, reg_val);
> +
> +       dev_dbg(dev, "Set reg 0x%x Delay(a=%d g=%d), Elements(C=%d F=%d)0x%x\n",
> +               val->offset, val->a_delay, val->g_delay, c_elements,
> +               f_elements, reg_val);
> +
> +       return r;
> +}

Looking at this terse thing I think it's obviously easier to use
a more verbose device tree description with

drive-delay = <some SI unit>;


> +       /* unlock the IOdelay region */
> +       r = regmap_update_bits(iod->regmap, reg->reg_global_lock_offset,
> +                              reg->global_lock_mask, reg->global_unlock_val);
> +       if (r)
> +               return r;
> +
> +       /* Read up Recalibration sequence done by bootloader */
> +       r = regmap_read(iod->regmap, reg->reg_refclk_offset, &val);
> +       if (r)
> +               return r;
> +       ival->ref_clk_period = ti_iodelay_extract(val, reg->refclk_period_mask);
> +       dev_dbg(dev, "refclk_period=0x%04x\n", ival->ref_clk_period);

That sounds hightec. So the bootloader calibrates the delays
and  computes the refclock period? So is that sime PLL or something?

> +       r = regmap_read(iod->regmap, reg->reg_coarse_offset, &val);
> +       if (r)
> +               return r;
> +       ival->coarse_ref_count =
> +           ti_iodelay_extract(val, reg->coarse_ref_count_mask);
> +       ival->coarse_delay_count =
> +           ti_iodelay_extract(val, reg->coarse_delay_count_mask);
> +       if (!ival->coarse_delay_count) {
> +               dev_err(dev, "Invalid Coarse delay count (0) (reg=0x%08x)\n",
> +                       val);
> +               return -EINVAL;
> +       }
> +       ival->cdpe = ti_iodelay_compute_dpe(ival->ref_clk_period,
> +                                           ival->coarse_ref_count,
> +                                           ival->coarse_delay_count, 88);

88? What does that mean... This should be #defined I think.

> +static int ti_iodelay_dt_node_to_map(struct pinctrl_dev *pctldev,
> +                                    struct device_node *np,
> +                                    struct pinctrl_map **map,
> +                                    unsigned *num_maps)

If you use the generic bindings this quite complex parsing and
everything associated with it goes away into the core.

> +static void ti_iodelay_dt_free_map(struct pinctrl_dev *pctldev,
> +                                  struct pinctrl_map *map, unsigned num_maps)

Dito.

BTW even if you proceed this way I suspect these are verbatim
copies from pinctrl-single so they shold obviouslyt be abstracted
out as library functions in that case.

> +/**
> + * ti_iodelay_pinctrl_get_group_pins() - get group pins
> + * @pctldev:   pinctrl device representing IODelay device
> + * @gselector: Group selector
> + * @pins:      pointer to the pins
> + * @npins:     number of pins
> + *
> + * Dummy implementation since we do not track pins, we track configurations
> + * Forced by pinctrl's pinctrl_check_ops()
> + *
> + * Return: -EINVAL
> + */
> +static int ti_iodelay_pinctrl_get_group_pins(struct pinctrl_dev *pctldev,
> +                                            unsigned gselector,
> +                                            const unsigned **pins,
> +                                            unsigned *npins)
> +{
> +       /* Dummy implementation - we dont do pin mux */
> +       return -EINVAL;
> +}

This is not about muxing. It is about enumerating the pins in the
group that will be affected by the setting, which is something you
will want to do when using the generic bindings.

> +       group = ti_iodelay_get_group(iod, gselector);

And this seems to be your re-implementation of exactly that pin control
core functionality. Which again should be shared with pinctrl-single if
you anyway go down this path.

I'll halt review here pending discussion on the bindings & stuff.

Yours,
Linus Walleij

Re: [PATCH 2/2] pinctrl: Introduce TI IOdelay configuration driver

[Linus Walleij]

On Wed, Mar 4, 2015 at 1:00 AM, Nishanth Menon <nm@ti.com> wrote:

> SoC family such as DRA7 family of processors have, in addition
> to the regular muxing of pins (as done by pinctrl-single), an
> additional hardware module called IODelay which is also expected to be
> configured. This "IODelay" module has it's own register space that is
> independent of the control module.
>
> It is advocated strongly in TI's official documentation considering
> the existing design of the DRA7 family of processors during mux or
> IODelay reconfiguration, there is a potential for a significant glitch
> which may cause functional impairment to certain hardware. It is
> hence recommended to do as little of muxing as absolutely necessary
> without I/O isolation (which can only be done in initial stages of
> bootloader).
>
> NOTE: with the system wide I/O isolation scheme present in DRA7 SoC
> family, it is not reasonable to do stop all I/O operations for every
> such pad configuration scheme. So, we will let it glitch when used in
> this mode.
>
> Even with the above limitation, certain functionality such as MMC has
> mandatory need for IODelay reconfiguration requirements, depending on
> speed of transfer. In these cases, with careful examination of usecase
> involved, the expected glitch can be controlled such that it does not
> impact functionality.
>
> In short, IODelay module support as a padconf driver being introduced
> here is not expected to do SoC wide I/O Isolation and is meant for
> a limited subset of IODelay configuration requirements that need to
> be dynamic and whose glitchy behavior will not cause functionality
> failure for that interface.
>
> Signed-off-by: Nishanth Menon <nm@ti.com>
> Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>

Pending the conclusion of my remark on the bindings that this
should use the generic pin config bindings... here are some
"normal" review comments.

> +config PINCTRL_TI_IODELAY
> +       bool "TI IODelay Module pinconf driver"
> +       depends on OF
> +       select PINCONF
> +       select GENERIC_PINCONF
> +       select REGMAP_MMIO
> +       help
> +         Say Y here to support Texas Instruments' IODelay pinconf driver.
> +         IODelay module is used for the DRA7 SoC family. This driver is in
> +         addition to PINCTRL_SINGLE which controls the mux.

If the driver is "in addition to PINCTRL_SINGLE", then it
should depend on it.

> +/* Should I change this? Abuse? */
> +#define IODELAY_MUX_PINS_NAME          "pinctrl-single,pins"

Yeah this is abuse and is why you should use the generic
bindings with just "pins" instead, and use the generic pinconf
parameters to set them up.

> + * struct ti_iodelay_conf_vals - Description of each configuration parameters.
> + * @offset:    Configuration register offset
> + * @a_delay:   Agnostic Delay (in ps)
> + * @g_delay:   Gnostic Delay (in ps)
> + */
> +struct ti_iodelay_conf_vals {
> +       u16 offset;
> +       u16 a_delay;
> +       u16 g_delay;
> +};

So I don't think it's a good idea to get the register offset from
the device tree. The driver should know these.

> +/**
> + * struct ti_iodelay_reg_values - Computed io_reg configuration values (see TRM)
> + * @coarse_ref_count:  Coarse reference count
> + * @coarse_delay_count:        Coarse delay count
> + * @fine_ref_count:    Fine reference count
> + * @fine_delay_count:  Fine Delay count
> + * @ref_clk_period:    Reference Clock period
> + * @cdpe:              Coarse delay parameter
> + * @fdpe:              Fine delay parameter
> + */
> +struct ti_iodelay_reg_values {
> +       u16 coarse_ref_count;

If you're doing reference counting, use kref.
<linux/kref.h>

> +       u16 coarse_delay_count;
> +
> +       u16 fine_ref_count;

Dito.

> +       u16 fine_delay_count;
> +
> +       u16 ref_clk_period;
> +
> +       u32 cdpe;
> +       u32 fdpe;
> +};


> +/**
> + * struct ti_iodelay_pin_name - name of the pins
> + * @name: name
> + */
> +struct ti_iodelay_pin_name {
> +       char name[IODELAY_REG_NAME_LEN];
> +};

What is this? The pin control subsystem already has a struct
for naming pins. struct pinctrl_pin_desc.

Are you reimplementing core functionality?

The generic pin config reference pins by name, and since you
obviously like to encode these into you data you can just
as well use that method for this too.

Again I think this is a side effect from using the pinctrl-single
concepts, if you think of this as some other pinctrl driver
I think this will fall out nicely.

> +/**
> + * struct ti_iodelay_device - Represents information for a IOdelay instance
> + * @dev: device pointer
> + * @reg_base: Remapped virtual address
> + * @regmap: Regmap for this IOdelay instance
> + * @pctl: Pinctrl device
> + * @desc: pinctrl descriptor for pctl
> + * @pa: pinctrl pin wise description
> + * @names: names of the pins
> + * @groups: list of pinconf groups for iodelay instance
> + * @ngroups: number of groups in the list
> + * @mutex: mutex to protect group list modification
> + * @reg_data: Register definition data for the IODelay instance
> + * @reg_init_conf_values: Initial configuration values.
> + */
> +struct ti_iodelay_device {
> +       struct device *dev;
> +       void __iomem *reg_base;
> +       struct regmap *regmap;
> +
> +       struct pinctrl_dev *pctl;
> +       struct pinctrl_desc desc;
> +       struct pinctrl_pin_desc *pa;
> +       struct ti_iodelay_pin_name *names;

Unhappy about that. pinctrl_desc contains
struct pinctrl_pin_desc const *pins; !

> +
> +       struct list_head groups;
> +       int ngroups;
> +       struct mutex mutex; /* list protection */

Why is this needed? Usually the pin control core
serialize calls into the drivers. Care to explain? Have
the potential race really triggered?

> +static inline u32 ti_iodelay_compute_dpe(u16 period, u16 ref, u16 delay,
> +                                        u16 delay_m)
> +{
> +       u64 m, d;
> +
> +       /* Handle overflow conditions */
> +       m = 10 * (u64)period * (u64)ref;
> +       d = 2 * (u64)delay * (u64)delay_m;
> +
> +       /* Truncate result back to 32 bits */
> +       return div64_u64(m, d);
> +}

Serious business ...

> +/**
> + * ti_iodelay_pinconf_set() - Configure the pin configuration
> + * @iod:       IODelay device
> + * @val:       Configuration value
> + *
> + * Update the configuration register as per TRM and lockup once done.
> + * *IMPORTANT NOTE* SoC TRM does recommend doing iodelay programmation only
> + * while in Isolation. But, then, isolation also implies that every pin
> + * on the SoC(including DDR) will be isolated out. The only benefit being
> + * a glitchless configuration, However, the intent of this driver is purely
> + * to support a "glitchy" configuration where applicable.
> + *
> + * Return: 0 in case of success, else appropriate error value
> + */
> +static int ti_iodelay_pinconf_set(struct ti_iodelay_device *iod,
> +                                 struct ti_iodelay_conf_vals *val)
> +{
> +       const struct ti_iodelay_reg_data *reg = iod->reg_data;
> +       struct ti_iodelay_reg_values *ival = &iod->reg_init_conf_values;
> +       struct device *dev = iod->dev;
> +       u32 g_delay_coarse, g_delay_fine;
> +       u32 a_delay_coarse, a_delay_fine;
> +       u32 c_elements, f_elements;
> +       u32 total_delay;
> +       u32 reg_mask, reg_val, tmp_val;
> +       int r;
> +
> +       /* NOTE: Truncation is expected in all division below */
> +       g_delay_coarse = val->g_delay / 920;
> +       g_delay_fine = ((val->g_delay % 920) * 10) / 60;
> +
> +       a_delay_coarse = val->a_delay / ival->cdpe;
> +       a_delay_fine = ((val->a_delay % ival->cdpe) * 10) / ival->fdpe;
> +
> +       c_elements = g_delay_coarse + a_delay_coarse;
> +       f_elements = (g_delay_fine + a_delay_fine) / 10;
> +
> +       if (f_elements > 22) {
> +               total_delay = c_elements * ival->cdpe + f_elements * ival->fdpe;
> +               c_elements = total_delay / ival->cdpe;
> +               f_elements = (total_delay % ival->cdpe) / ival->fdpe;
> +       }
> +
> +       reg_mask = reg->signature_mask;
> +       reg_val = reg->signature_value << __ffs(reg->signature_mask);
> +
> +       reg_mask |= reg->binary_data_coarse_mask;
> +       tmp_val = c_elements << __ffs(reg->binary_data_coarse_mask);
> +       if (tmp_val & ~reg->binary_data_coarse_mask) {
> +               dev_err(dev, "Masking overflow of coarse elements %08x\n",
> +                       tmp_val);
> +               tmp_val &= reg->binary_data_coarse_mask;
> +       }
> +       reg_val |= tmp_val;
> +
> +       reg_mask |= reg->binary_data_fine_mask;
> +       tmp_val = f_elements << __ffs(reg->binary_data_fine_mask);
> +       if (tmp_val & ~reg->binary_data_fine_mask) {
> +               dev_err(dev, "Masking overflow of fine elements %08x\n",
> +                       tmp_val);
> +               tmp_val &= reg->binary_data_fine_mask;
> +       }
> +       reg_val |= tmp_val;
> +
> +       /* Write with lock value - we DONOT want h/w updates */
> +       reg_mask |= reg->lock_mask;
> +       reg_val |= reg->lock_val << __ffs(reg->lock_mask);
> +       r = regmap_update_bits(iod->regmap, val->offset, reg_mask, reg_val);
> +
> +       dev_dbg(dev, "Set reg 0x%x Delay(a=%d g=%d), Elements(C=%d F=%d)0x%x\n",
> +               val->offset, val->a_delay, val->g_delay, c_elements,
> +               f_elements, reg_val);
> +
> +       return r;
> +}

Looking at this terse thing I think it's obviously easier to use
a more verbose device tree description with

drive-delay = <some SI unit>;


> +       /* unlock the IOdelay region */
> +       r = regmap_update_bits(iod->regmap, reg->reg_global_lock_offset,
> +                              reg->global_lock_mask, reg->global_unlock_val);
> +       if (r)
> +               return r;
> +
> +       /* Read up Recalibration sequence done by bootloader */
> +       r = regmap_read(iod->regmap, reg->reg_refclk_offset, &val);
> +       if (r)
> +               return r;
> +       ival->ref_clk_period = ti_iodelay_extract(val, reg->refclk_period_mask);
> +       dev_dbg(dev, "refclk_period=0x%04x\n", ival->ref_clk_period);

That sounds hightec. So the bootloader calibrates the delays
and  computes the refclock period? So is that sime PLL or something?

> +       r = regmap_read(iod->regmap, reg->reg_coarse_offset, &val);
> +       if (r)
> +               return r;
> +       ival->coarse_ref_count =
> +           ti_iodelay_extract(val, reg->coarse_ref_count_mask);
> +       ival->coarse_delay_count =
> +           ti_iodelay_extract(val, reg->coarse_delay_count_mask);
> +       if (!ival->coarse_delay_count) {
> +               dev_err(dev, "Invalid Coarse delay count (0) (reg=0x%08x)\n",
> +                       val);
> +               return -EINVAL;
> +       }
> +       ival->cdpe = ti_iodelay_compute_dpe(ival->ref_clk_period,
> +                                           ival->coarse_ref_count,
> +                                           ival->coarse_delay_count, 88);

88? What does that mean... This should be #defined I think.

> +static int ti_iodelay_dt_node_to_map(struct pinctrl_dev *pctldev,
> +                                    struct device_node *np,
> +                                    struct pinctrl_map **map,
> +                                    unsigned *num_maps)

If you use the generic bindings this quite complex parsing and
everything associated with it goes away into the core.

> +static void ti_iodelay_dt_free_map(struct pinctrl_dev *pctldev,
> +                                  struct pinctrl_map *map, unsigned num_maps)

Dito.

BTW even if you proceed this way I suspect these are verbatim
copies from pinctrl-single so they shold obviouslyt be abstracted
out as library functions in that case.

> +/**
> + * ti_iodelay_pinctrl_get_group_pins() - get group pins
> + * @pctldev:   pinctrl device representing IODelay device
> + * @gselector: Group selector
> + * @pins:      pointer to the pins
> + * @npins:     number of pins
> + *
> + * Dummy implementation since we do not track pins, we track configurations
> + * Forced by pinctrl's pinctrl_check_ops()
> + *
> + * Return: -EINVAL
> + */
> +static int ti_iodelay_pinctrl_get_group_pins(struct pinctrl_dev *pctldev,
> +                                            unsigned gselector,
> +                                            const unsigned **pins,
> +                                            unsigned *npins)
> +{
> +       /* Dummy implementation - we dont do pin mux */
> +       return -EINVAL;
> +}

This is not about muxing. It is about enumerating the pins in the
group that will be affected by the setting, which is something you
will want to do when using the generic bindings.

> +       group = ti_iodelay_get_group(iod, gselector);

And this seems to be your re-implementation of exactly that pin control
core functionality. Which again should be shared with pinctrl-single if
you anyway go down this path.

I'll halt review here pending discussion on the bindings & stuff.

Yours,
Linus Walleij

Re: [PATCH 2/2] pinctrl: Introduce TI IOdelay configuration driver

[Nishanth Menon]

On Tue, Mar 10, 2015 at 6:03 AM, Linus Walleij <linus.walleij@linaro.org> wrote:
> On Wed, Mar 4, 2015 at 1:00 AM, Nishanth Menon <nm@ti.com> wrote:
>
>> SoC family such as DRA7 family of processors have, in addition
>> to the regular muxing of pins (as done by pinctrl-single), an
>> additional hardware module called IODelay which is also expected to be
>> configured. This "IODelay" module has it's own register space that is
>> independent of the control module.
>>
>> It is advocated strongly in TI's official documentation considering
>> the existing design of the DRA7 family of processors during mux or
>> IODelay reconfiguration, there is a potential for a significant glitch
>> which may cause functional impairment to certain hardware. It is
>> hence recommended to do as little of muxing as absolutely necessary
>> without I/O isolation (which can only be done in initial stages of
>> bootloader).
>>
>> NOTE: with the system wide I/O isolation scheme present in DRA7 SoC
>> family, it is not reasonable to do stop all I/O operations for every
>> such pad configuration scheme. So, we will let it glitch when used in
>> this mode.
>>
>> Even with the above limitation, certain functionality such as MMC has
>> mandatory need for IODelay reconfiguration requirements, depending on
>> speed of transfer. In these cases, with careful examination of usecase
>> involved, the expected glitch can be controlled such that it does not
>> impact functionality.
>>
>> In short, IODelay module support as a padconf driver being introduced
>> here is not expected to do SoC wide I/O Isolation and is meant for
>> a limited subset of IODelay configuration requirements that need to
>> be dynamic and whose glitchy behavior will not cause functionality
>> failure for that interface.
>>
>> Signed-off-by: Nishanth Menon <nm@ti.com>
>> Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
>
> Pending the conclusion of my remark on the bindings that this
> should use the generic pin config bindings... here are some
> "normal" review comments.
>
>> +config PINCTRL_TI_IODELAY
>> +       bool "TI IODelay Module pinconf driver"
>> +       depends on OF
>> +       select PINCONF
>> +       select GENERIC_PINCONF
>> +       select REGMAP_MMIO
>> +       help
>> +         Say Y here to support Texas Instruments' IODelay pinconf driver.
>> +         IODelay module is used for the DRA7 SoC family. This driver is in
>> +         addition to PINCTRL_SINGLE which controls the mux.
>
> If the driver is "in addition to PINCTRL_SINGLE", then it
> should depend on it.
>
>> +/* Should I change this? Abuse? */
>> +#define IODELAY_MUX_PINS_NAME          "pinctrl-single,pins"
>
> Yeah this is abuse and is why you should use the generic
> bindings with just "pins" instead, and use the generic pinconf
> parameters to set them up.
>
>> + * struct ti_iodelay_conf_vals - Description of each configuration parameters.
>> + * @offset:    Configuration register offset
>> + * @a_delay:   Agnostic Delay (in ps)
>> + * @g_delay:   Gnostic Delay (in ps)
>> + */
>> +struct ti_iodelay_conf_vals {
>> +       u16 offset;
>> +       u16 a_delay;
>> +       u16 g_delay;
>> +};
>
> So I don't think it's a good idea to get the register offset from
> the device tree. The driver should know these.
>
>> +/**
>> + * struct ti_iodelay_reg_values - Computed io_reg configuration values (see TRM)
>> + * @coarse_ref_count:  Coarse reference count
>> + * @coarse_delay_count:        Coarse delay count
>> + * @fine_ref_count:    Fine reference count
>> + * @fine_delay_count:  Fine Delay count
>> + * @ref_clk_period:    Reference Clock period
>> + * @cdpe:              Coarse delay parameter
>> + * @fdpe:              Fine delay parameter
>> + */
>> +struct ti_iodelay_reg_values {
>> +       u16 coarse_ref_count;
>
> If you're doing reference counting, use kref.
> <linux/kref.h>
>
>> +       u16 coarse_delay_count;
>> +
>> +       u16 fine_ref_count;
>
> Dito.
>
>> +       u16 fine_delay_count;
>> +
>> +       u16 ref_clk_period;
>> +
>> +       u32 cdpe;
>> +       u32 fdpe;
>> +};
>
>
>> +/**
>> + * struct ti_iodelay_pin_name - name of the pins
>> + * @name: name
>> + */
>> +struct ti_iodelay_pin_name {
>> +       char name[IODELAY_REG_NAME_LEN];
>> +};
>
> What is this? The pin control subsystem already has a struct
> for naming pins. struct pinctrl_pin_desc.
>
> Are you reimplementing core functionality?
>
> The generic pin config reference pins by name, and since you
> obviously like to encode these into you data you can just
> as well use that method for this too.
>
> Again I think this is a side effect from using the pinctrl-single
> concepts, if you think of this as some other pinctrl driver
> I think this will fall out nicely.
>
>> +/**
>> + * struct ti_iodelay_device - Represents information for a IOdelay instance
>> + * @dev: device pointer
>> + * @reg_base: Remapped virtual address
>> + * @regmap: Regmap for this IOdelay instance
>> + * @pctl: Pinctrl device
>> + * @desc: pinctrl descriptor for pctl
>> + * @pa: pinctrl pin wise description
>> + * @names: names of the pins
>> + * @groups: list of pinconf groups for iodelay instance
>> + * @ngroups: number of groups in the list
>> + * @mutex: mutex to protect group list modification
>> + * @reg_data: Register definition data for the IODelay instance
>> + * @reg_init_conf_values: Initial configuration values.
>> + */
>> +struct ti_iodelay_device {
>> +       struct device *dev;
>> +       void __iomem *reg_base;
>> +       struct regmap *regmap;
>> +
>> +       struct pinctrl_dev *pctl;
>> +       struct pinctrl_desc desc;
>> +       struct pinctrl_pin_desc *pa;
>> +       struct ti_iodelay_pin_name *names;
>
> Unhappy about that. pinctrl_desc contains
> struct pinctrl_pin_desc const *pins; !
>
>> +
>> +       struct list_head groups;
>> +       int ngroups;
>> +       struct mutex mutex; /* list protection */
>
> Why is this needed? Usually the pin control core
> serialize calls into the drivers. Care to explain? Have
> the potential race really triggered?
>
>> +static inline u32 ti_iodelay_compute_dpe(u16 period, u16 ref, u16 delay,
>> +                                        u16 delay_m)
>> +{
>> +       u64 m, d;
>> +
>> +       /* Handle overflow conditions */
>> +       m = 10 * (u64)period * (u64)ref;
>> +       d = 2 * (u64)delay * (u64)delay_m;
>> +
>> +       /* Truncate result back to 32 bits */
>> +       return div64_u64(m, d);
>> +}
>
> Serious business ...
>
>> +/**
>> + * ti_iodelay_pinconf_set() - Configure the pin configuration
>> + * @iod:       IODelay device
>> + * @val:       Configuration value
>> + *
>> + * Update the configuration register as per TRM and lockup once done.
>> + * *IMPORTANT NOTE* SoC TRM does recommend doing iodelay programmation only
>> + * while in Isolation. But, then, isolation also implies that every pin
>> + * on the SoC(including DDR) will be isolated out. The only benefit being
>> + * a glitchless configuration, However, the intent of this driver is purely
>> + * to support a "glitchy" configuration where applicable.
>> + *
>> + * Return: 0 in case of success, else appropriate error value
>> + */
>> +static int ti_iodelay_pinconf_set(struct ti_iodelay_device *iod,
>> +                                 struct ti_iodelay_conf_vals *val)
>> +{
>> +       const struct ti_iodelay_reg_data *reg = iod->reg_data;
>> +       struct ti_iodelay_reg_values *ival = &iod->reg_init_conf_values;
>> +       struct device *dev = iod->dev;
>> +       u32 g_delay_coarse, g_delay_fine;
>> +       u32 a_delay_coarse, a_delay_fine;
>> +       u32 c_elements, f_elements;
>> +       u32 total_delay;
>> +       u32 reg_mask, reg_val, tmp_val;
>> +       int r;
>> +
>> +       /* NOTE: Truncation is expected in all division below */
>> +       g_delay_coarse = val->g_delay / 920;
>> +       g_delay_fine = ((val->g_delay % 920) * 10) / 60;
>> +
>> +       a_delay_coarse = val->a_delay / ival->cdpe;
>> +       a_delay_fine = ((val->a_delay % ival->cdpe) * 10) / ival->fdpe;
>> +
>> +       c_elements = g_delay_coarse + a_delay_coarse;
>> +       f_elements = (g_delay_fine + a_delay_fine) / 10;
>> +
>> +       if (f_elements > 22) {
>> +               total_delay = c_elements * ival->cdpe + f_elements * ival->fdpe;
>> +               c_elements = total_delay / ival->cdpe;
>> +               f_elements = (total_delay % ival->cdpe) / ival->fdpe;
>> +       }
>> +
>> +       reg_mask = reg->signature_mask;
>> +       reg_val = reg->signature_value << __ffs(reg->signature_mask);
>> +
>> +       reg_mask |= reg->binary_data_coarse_mask;
>> +       tmp_val = c_elements << __ffs(reg->binary_data_coarse_mask);
>> +       if (tmp_val & ~reg->binary_data_coarse_mask) {
>> +               dev_err(dev, "Masking overflow of coarse elements %08x\n",
>> +                       tmp_val);
>> +               tmp_val &= reg->binary_data_coarse_mask;
>> +       }
>> +       reg_val |= tmp_val;
>> +
>> +       reg_mask |= reg->binary_data_fine_mask;
>> +       tmp_val = f_elements << __ffs(reg->binary_data_fine_mask);
>> +       if (tmp_val & ~reg->binary_data_fine_mask) {
>> +               dev_err(dev, "Masking overflow of fine elements %08x\n",
>> +                       tmp_val);
>> +               tmp_val &= reg->binary_data_fine_mask;
>> +       }
>> +       reg_val |= tmp_val;
>> +
>> +       /* Write with lock value - we DONOT want h/w updates */
>> +       reg_mask |= reg->lock_mask;
>> +       reg_val |= reg->lock_val << __ffs(reg->lock_mask);
>> +       r = regmap_update_bits(iod->regmap, val->offset, reg_mask, reg_val);
>> +
>> +       dev_dbg(dev, "Set reg 0x%x Delay(a=%d g=%d), Elements(C=%d F=%d)0x%x\n",
>> +               val->offset, val->a_delay, val->g_delay, c_elements,
>> +               f_elements, reg_val);
>> +
>> +       return r;
>> +}
>
> Looking at this terse thing I think it's obviously easier to use
> a more verbose device tree description with
>
> drive-delay = <some SI unit>;
>
>
>> +       /* unlock the IOdelay region */
>> +       r = regmap_update_bits(iod->regmap, reg->reg_global_lock_offset,
>> +                              reg->global_lock_mask, reg->global_unlock_val);
>> +       if (r)
>> +               return r;
>> +
>> +       /* Read up Recalibration sequence done by bootloader */
>> +       r = regmap_read(iod->regmap, reg->reg_refclk_offset, &val);
>> +       if (r)
>> +               return r;
>> +       ival->ref_clk_period = ti_iodelay_extract(val, reg->refclk_period_mask);
>> +       dev_dbg(dev, "refclk_period=0x%04x\n", ival->ref_clk_period);
>
> That sounds hightec. So the bootloader calibrates the delays
> and  computes the refclock period? So is that sime PLL or something?
>
>> +       r = regmap_read(iod->regmap, reg->reg_coarse_offset, &val);
>> +       if (r)
>> +               return r;
>> +       ival->coarse_ref_count =
>> +           ti_iodelay_extract(val, reg->coarse_ref_count_mask);
>> +       ival->coarse_delay_count =
>> +           ti_iodelay_extract(val, reg->coarse_delay_count_mask);
>> +       if (!ival->coarse_delay_count) {
>> +               dev_err(dev, "Invalid Coarse delay count (0) (reg=0x%08x)\n",
>> +                       val);
>> +               return -EINVAL;
>> +       }
>> +       ival->cdpe = ti_iodelay_compute_dpe(ival->ref_clk_period,
>> +                                           ival->coarse_ref_count,
>> +                                           ival->coarse_delay_count, 88);
>
> 88? What does that mean... This should be #defined I think.
>
>> +static int ti_iodelay_dt_node_to_map(struct pinctrl_dev *pctldev,
>> +                                    struct device_node *np,
>> +                                    struct pinctrl_map **map,
>> +                                    unsigned *num_maps)
>
> If you use the generic bindings this quite complex parsing and
> everything associated with it goes away into the core.
>
>> +static void ti_iodelay_dt_free_map(struct pinctrl_dev *pctldev,
>> +                                  struct pinctrl_map *map, unsigned num_maps)
>
> Dito.
>
> BTW even if you proceed this way I suspect these are verbatim
> copies from pinctrl-single so they shold obviouslyt be abstracted
> out as library functions in that case.
>
>> +/**
>> + * ti_iodelay_pinctrl_get_group_pins() - get group pins
>> + * @pctldev:   pinctrl device representing IODelay device
>> + * @gselector: Group selector
>> + * @pins:      pointer to the pins
>> + * @npins:     number of pins
>> + *
>> + * Dummy implementation since we do not track pins, we track configurations
>> + * Forced by pinctrl's pinctrl_check_ops()
>> + *
>> + * Return: -EINVAL
>> + */
>> +static int ti_iodelay_pinctrl_get_group_pins(struct pinctrl_dev *pctldev,
>> +                                            unsigned gselector,
>> +                                            const unsigned **pins,
>> +                                            unsigned *npins)
>> +{
>> +       /* Dummy implementation - we dont do pin mux */
>> +       return -EINVAL;
>> +}
>
> This is not about muxing. It is about enumerating the pins in the
> group that will be affected by the setting, which is something you
> will want to do when using the generic bindings.
>
>> +       group = ti_iodelay_get_group(iod, gselector);
>
> And this seems to be your re-implementation of exactly that pin control
> core functionality. Which again should be shared with pinctrl-single if
> you anyway go down this path.
>
> I'll halt review here pending discussion on the bindings & stuff.

I assume we want to close on binding before looking at implementation
- definitely needs a rewrite - only guidance I'd probably need is
about which model you'd suggest I should follow(pinconf/pinctrl) once
we are done with the bindings discussion.

-- 
---
Regards,
Nishanth Menon

[PATCH 2/2] pinctrl: Introduce TI IOdelay configuration driver

[Nishanth Menon]

On Tue, Mar 10, 2015 at 6:03 AM, Linus Walleij <linus.walleij@linaro.org> wrote:
> On Wed, Mar 4, 2015 at 1:00 AM, Nishanth Menon <nm@ti.com> wrote:
>
>> SoC family such as DRA7 family of processors have, in addition
>> to the regular muxing of pins (as done by pinctrl-single), an
>> additional hardware module called IODelay which is also expected to be
>> configured. This "IODelay" module has it's own register space that is
>> independent of the control module.
>>
>> It is advocated strongly in TI's official documentation considering
>> the existing design of the DRA7 family of processors during mux or
>> IODelay reconfiguration, there is a potential for a significant glitch
>> which may cause functional impairment to certain hardware. It is
>> hence recommended to do as little of muxing as absolutely necessary
>> without I/O isolation (which can only be done in initial stages of
>> bootloader).
>>
>> NOTE: with the system wide I/O isolation scheme present in DRA7 SoC
>> family, it is not reasonable to do stop all I/O operations for every
>> such pad configuration scheme. So, we will let it glitch when used in
>> this mode.
>>
>> Even with the above limitation, certain functionality such as MMC has
>> mandatory need for IODelay reconfiguration requirements, depending on
>> speed of transfer. In these cases, with careful examination of usecase
>> involved, the expected glitch can be controlled such that it does not
>> impact functionality.
>>
>> In short, IODelay module support as a padconf driver being introduced
>> here is not expected to do SoC wide I/O Isolation and is meant for
>> a limited subset of IODelay configuration requirements that need to
>> be dynamic and whose glitchy behavior will not cause functionality
>> failure for that interface.
>>
>> Signed-off-by: Nishanth Menon <nm@ti.com>
>> Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
>
> Pending the conclusion of my remark on the bindings that this
> should use the generic pin config bindings... here are some
> "normal" review comments.
>
>> +config PINCTRL_TI_IODELAY
>> +       bool "TI IODelay Module pinconf driver"
>> +       depends on OF
>> +       select PINCONF
>> +       select GENERIC_PINCONF
>> +       select REGMAP_MMIO
>> +       help
>> +         Say Y here to support Texas Instruments' IODelay pinconf driver.
>> +         IODelay module is used for the DRA7 SoC family. This driver is in
>> +         addition to PINCTRL_SINGLE which controls the mux.
>
> If the driver is "in addition to PINCTRL_SINGLE", then it
> should depend on it.
>
>> +/* Should I change this? Abuse? */
>> +#define IODELAY_MUX_PINS_NAME          "pinctrl-single,pins"
>
> Yeah this is abuse and is why you should use the generic
> bindings with just "pins" instead, and use the generic pinconf
> parameters to set them up.
>
>> + * struct ti_iodelay_conf_vals - Description of each configuration parameters.
>> + * @offset:    Configuration register offset
>> + * @a_delay:   Agnostic Delay (in ps)
>> + * @g_delay:   Gnostic Delay (in ps)
>> + */
>> +struct ti_iodelay_conf_vals {
>> +       u16 offset;
>> +       u16 a_delay;
>> +       u16 g_delay;
>> +};
>
> So I don't think it's a good idea to get the register offset from
> the device tree. The driver should know these.
>
>> +/**
>> + * struct ti_iodelay_reg_values - Computed io_reg configuration values (see TRM)
>> + * @coarse_ref_count:  Coarse reference count
>> + * @coarse_delay_count:        Coarse delay count
>> + * @fine_ref_count:    Fine reference count
>> + * @fine_delay_count:  Fine Delay count
>> + * @ref_clk_period:    Reference Clock period
>> + * @cdpe:              Coarse delay parameter
>> + * @fdpe:              Fine delay parameter
>> + */
>> +struct ti_iodelay_reg_values {
>> +       u16 coarse_ref_count;
>
> If you're doing reference counting, use kref.
> <linux/kref.h>
>
>> +       u16 coarse_delay_count;
>> +
>> +       u16 fine_ref_count;
>
> Dito.
>
>> +       u16 fine_delay_count;
>> +
>> +       u16 ref_clk_period;
>> +
>> +       u32 cdpe;
>> +       u32 fdpe;
>> +};
>
>
>> +/**
>> + * struct ti_iodelay_pin_name - name of the pins
>> + * @name: name
>> + */
>> +struct ti_iodelay_pin_name {
>> +       char name[IODELAY_REG_NAME_LEN];
>> +};
>
> What is this? The pin control subsystem already has a struct
> for naming pins. struct pinctrl_pin_desc.
>
> Are you reimplementing core functionality?
>
> The generic pin config reference pins by name, and since you
> obviously like to encode these into you data you can just
> as well use that method for this too.
>
> Again I think this is a side effect from using the pinctrl-single
> concepts, if you think of this as some other pinctrl driver
> I think this will fall out nicely.
>
>> +/**
>> + * struct ti_iodelay_device - Represents information for a IOdelay instance
>> + * @dev: device pointer
>> + * @reg_base: Remapped virtual address
>> + * @regmap: Regmap for this IOdelay instance
>> + * @pctl: Pinctrl device
>> + * @desc: pinctrl descriptor for pctl
>> + * @pa: pinctrl pin wise description
>> + * @names: names of the pins
>> + * @groups: list of pinconf groups for iodelay instance
>> + * @ngroups: number of groups in the list
>> + * @mutex: mutex to protect group list modification
>> + * @reg_data: Register definition data for the IODelay instance
>> + * @reg_init_conf_values: Initial configuration values.
>> + */
>> +struct ti_iodelay_device {
>> +       struct device *dev;
>> +       void __iomem *reg_base;
>> +       struct regmap *regmap;
>> +
>> +       struct pinctrl_dev *pctl;
>> +       struct pinctrl_desc desc;
>> +       struct pinctrl_pin_desc *pa;
>> +       struct ti_iodelay_pin_name *names;
>
> Unhappy about that. pinctrl_desc contains
> struct pinctrl_pin_desc const *pins; !
>
>> +
>> +       struct list_head groups;
>> +       int ngroups;
>> +       struct mutex mutex; /* list protection */
>
> Why is this needed? Usually the pin control core
> serialize calls into the drivers. Care to explain? Have
> the potential race really triggered?
>
>> +static inline u32 ti_iodelay_compute_dpe(u16 period, u16 ref, u16 delay,
>> +                                        u16 delay_m)
>> +{
>> +       u64 m, d;
>> +
>> +       /* Handle overflow conditions */
>> +       m = 10 * (u64)period * (u64)ref;
>> +       d = 2 * (u64)delay * (u64)delay_m;
>> +
>> +       /* Truncate result back to 32 bits */
>> +       return div64_u64(m, d);
>> +}
>
> Serious business ...
>
>> +/**
>> + * ti_iodelay_pinconf_set() - Configure the pin configuration
>> + * @iod:       IODelay device
>> + * @val:       Configuration value
>> + *
>> + * Update the configuration register as per TRM and lockup once done.
>> + * *IMPORTANT NOTE* SoC TRM does recommend doing iodelay programmation only
>> + * while in Isolation. But, then, isolation also implies that every pin
>> + * on the SoC(including DDR) will be isolated out. The only benefit being
>> + * a glitchless configuration, However, the intent of this driver is purely
>> + * to support a "glitchy" configuration where applicable.
>> + *
>> + * Return: 0 in case of success, else appropriate error value
>> + */
>> +static int ti_iodelay_pinconf_set(struct ti_iodelay_device *iod,
>> +                                 struct ti_iodelay_conf_vals *val)
>> +{
>> +       const struct ti_iodelay_reg_data *reg = iod->reg_data;
>> +       struct ti_iodelay_reg_values *ival = &iod->reg_init_conf_values;
>> +       struct device *dev = iod->dev;
>> +       u32 g_delay_coarse, g_delay_fine;
>> +       u32 a_delay_coarse, a_delay_fine;
>> +       u32 c_elements, f_elements;
>> +       u32 total_delay;
>> +       u32 reg_mask, reg_val, tmp_val;
>> +       int r;
>> +
>> +       /* NOTE: Truncation is expected in all division below */
>> +       g_delay_coarse = val->g_delay / 920;
>> +       g_delay_fine = ((val->g_delay % 920) * 10) / 60;
>> +
>> +       a_delay_coarse = val->a_delay / ival->cdpe;
>> +       a_delay_fine = ((val->a_delay % ival->cdpe) * 10) / ival->fdpe;
>> +
>> +       c_elements = g_delay_coarse + a_delay_coarse;
>> +       f_elements = (g_delay_fine + a_delay_fine) / 10;
>> +
>> +       if (f_elements > 22) {
>> +               total_delay = c_elements * ival->cdpe + f_elements * ival->fdpe;
>> +               c_elements = total_delay / ival->cdpe;
>> +               f_elements = (total_delay % ival->cdpe) / ival->fdpe;
>> +       }
>> +
>> +       reg_mask = reg->signature_mask;
>> +       reg_val = reg->signature_value << __ffs(reg->signature_mask);
>> +
>> +       reg_mask |= reg->binary_data_coarse_mask;
>> +       tmp_val = c_elements << __ffs(reg->binary_data_coarse_mask);
>> +       if (tmp_val & ~reg->binary_data_coarse_mask) {
>> +               dev_err(dev, "Masking overflow of coarse elements %08x\n",
>> +                       tmp_val);
>> +               tmp_val &= reg->binary_data_coarse_mask;
>> +       }
>> +       reg_val |= tmp_val;
>> +
>> +       reg_mask |= reg->binary_data_fine_mask;
>> +       tmp_val = f_elements << __ffs(reg->binary_data_fine_mask);
>> +       if (tmp_val & ~reg->binary_data_fine_mask) {
>> +               dev_err(dev, "Masking overflow of fine elements %08x\n",
>> +                       tmp_val);
>> +               tmp_val &= reg->binary_data_fine_mask;
>> +       }
>> +       reg_val |= tmp_val;
>> +
>> +       /* Write with lock value - we DONOT want h/w updates */
>> +       reg_mask |= reg->lock_mask;
>> +       reg_val |= reg->lock_val << __ffs(reg->lock_mask);
>> +       r = regmap_update_bits(iod->regmap, val->offset, reg_mask, reg_val);
>> +
>> +       dev_dbg(dev, "Set reg 0x%x Delay(a=%d g=%d), Elements(C=%d F=%d)0x%x\n",
>> +               val->offset, val->a_delay, val->g_delay, c_elements,
>> +               f_elements, reg_val);
>> +
>> +       return r;
>> +}
>
> Looking at this terse thing I think it's obviously easier to use
> a more verbose device tree description with
>
> drive-delay = <some SI unit>;
>
>
>> +       /* unlock the IOdelay region */
>> +       r = regmap_update_bits(iod->regmap, reg->reg_global_lock_offset,
>> +                              reg->global_lock_mask, reg->global_unlock_val);
>> +       if (r)
>> +               return r;
>> +
>> +       /* Read up Recalibration sequence done by bootloader */
>> +       r = regmap_read(iod->regmap, reg->reg_refclk_offset, &val);
>> +       if (r)
>> +               return r;
>> +       ival->ref_clk_period = ti_iodelay_extract(val, reg->refclk_period_mask);
>> +       dev_dbg(dev, "refclk_period=0x%04x\n", ival->ref_clk_period);
>
> That sounds hightec. So the bootloader calibrates the delays
> and  computes the refclock period? So is that sime PLL or something?
>
>> +       r = regmap_read(iod->regmap, reg->reg_coarse_offset, &val);
>> +       if (r)
>> +               return r;
>> +       ival->coarse_ref_count =
>> +           ti_iodelay_extract(val, reg->coarse_ref_count_mask);
>> +       ival->coarse_delay_count =
>> +           ti_iodelay_extract(val, reg->coarse_delay_count_mask);
>> +       if (!ival->coarse_delay_count) {
>> +               dev_err(dev, "Invalid Coarse delay count (0) (reg=0x%08x)\n",
>> +                       val);
>> +               return -EINVAL;
>> +       }
>> +       ival->cdpe = ti_iodelay_compute_dpe(ival->ref_clk_period,
>> +                                           ival->coarse_ref_count,
>> +                                           ival->coarse_delay_count, 88);
>
> 88? What does that mean... This should be #defined I think.
>
>> +static int ti_iodelay_dt_node_to_map(struct pinctrl_dev *pctldev,
>> +                                    struct device_node *np,
>> +                                    struct pinctrl_map **map,
>> +                                    unsigned *num_maps)
>
> If you use the generic bindings this quite complex parsing and
> everything associated with it goes away into the core.
>
>> +static void ti_iodelay_dt_free_map(struct pinctrl_dev *pctldev,
>> +                                  struct pinctrl_map *map, unsigned num_maps)
>
> Dito.
>
> BTW even if you proceed this way I suspect these are verbatim
> copies from pinctrl-single so they shold obviouslyt be abstracted
> out as library functions in that case.
>
>> +/**
>> + * ti_iodelay_pinctrl_get_group_pins() - get group pins
>> + * @pctldev:   pinctrl device representing IODelay device
>> + * @gselector: Group selector
>> + * @pins:      pointer to the pins
>> + * @npins:     number of pins
>> + *
>> + * Dummy implementation since we do not track pins, we track configurations
>> + * Forced by pinctrl's pinctrl_check_ops()
>> + *
>> + * Return: -EINVAL
>> + */
>> +static int ti_iodelay_pinctrl_get_group_pins(struct pinctrl_dev *pctldev,
>> +                                            unsigned gselector,
>> +                                            const unsigned **pins,
>> +                                            unsigned *npins)
>> +{
>> +       /* Dummy implementation - we dont do pin mux */
>> +       return -EINVAL;
>> +}
>
> This is not about muxing. It is about enumerating the pins in the
> group that will be affected by the setting, which is something you
> will want to do when using the generic bindings.
>
>> +       group = ti_iodelay_get_group(iod, gselector);
>
> And this seems to be your re-implementation of exactly that pin control
> core functionality. Which again should be shared with pinctrl-single if
> you anyway go down this path.
>
> I'll halt review here pending discussion on the bindings & stuff.

I assume we want to close on binding before looking at implementation
- definitely needs a rewrite - only guidance I'd probably need is
about which model you'd suggest I should follow(pinconf/pinctrl) once
we are done with the bindings discussion.

-- 
---
Regards,
Nishanth Menon

Re: [PATCH 2/2] pinctrl: Introduce TI IOdelay configuration driver

[Nishanth Menon]

On Tue, Mar 10, 2015 at 6:03 AM, Linus Walleij <linus.walleij@linaro.org> wrote:
> On Wed, Mar 4, 2015 at 1:00 AM, Nishanth Menon <nm@ti.com> wrote:
>
>> SoC family such as DRA7 family of processors have, in addition
>> to the regular muxing of pins (as done by pinctrl-single), an
>> additional hardware module called IODelay which is also expected to be
>> configured. This "IODelay" module has it's own register space that is
>> independent of the control module.
>>
>> It is advocated strongly in TI's official documentation considering
>> the existing design of the DRA7 family of processors during mux or
>> IODelay reconfiguration, there is a potential for a significant glitch
>> which may cause functional impairment to certain hardware. It is
>> hence recommended to do as little of muxing as absolutely necessary
>> without I/O isolation (which can only be done in initial stages of
>> bootloader).
>>
>> NOTE: with the system wide I/O isolation scheme present in DRA7 SoC
>> family, it is not reasonable to do stop all I/O operations for every
>> such pad configuration scheme. So, we will let it glitch when used in
>> this mode.
>>
>> Even with the above limitation, certain functionality such as MMC has
>> mandatory need for IODelay reconfiguration requirements, depending on
>> speed of transfer. In these cases, with careful examination of usecase
>> involved, the expected glitch can be controlled such that it does not
>> impact functionality.
>>
>> In short, IODelay module support as a padconf driver being introduced
>> here is not expected to do SoC wide I/O Isolation and is meant for
>> a limited subset of IODelay configuration requirements that need to
>> be dynamic and whose glitchy behavior will not cause functionality
>> failure for that interface.
>>
>> Signed-off-by: Nishanth Menon <nm@ti.com>
>> Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
>
> Pending the conclusion of my remark on the bindings that this
> should use the generic pin config bindings... here are some
> "normal" review comments.
>
>> +config PINCTRL_TI_IODELAY
>> +       bool "TI IODelay Module pinconf driver"
>> +       depends on OF
>> +       select PINCONF
>> +       select GENERIC_PINCONF
>> +       select REGMAP_MMIO
>> +       help
>> +         Say Y here to support Texas Instruments' IODelay pinconf driver.
>> +         IODelay module is used for the DRA7 SoC family. This driver is in
>> +         addition to PINCTRL_SINGLE which controls the mux.
>
> If the driver is "in addition to PINCTRL_SINGLE", then it
> should depend on it.
>
>> +/* Should I change this? Abuse? */
>> +#define IODELAY_MUX_PINS_NAME          "pinctrl-single,pins"
>
> Yeah this is abuse and is why you should use the generic
> bindings with just "pins" instead, and use the generic pinconf
> parameters to set them up.
>
>> + * struct ti_iodelay_conf_vals - Description of each configuration parameters.
>> + * @offset:    Configuration register offset
>> + * @a_delay:   Agnostic Delay (in ps)
>> + * @g_delay:   Gnostic Delay (in ps)
>> + */
>> +struct ti_iodelay_conf_vals {
>> +       u16 offset;
>> +       u16 a_delay;
>> +       u16 g_delay;
>> +};
>
> So I don't think it's a good idea to get the register offset from
> the device tree. The driver should know these.
>
>> +/**
>> + * struct ti_iodelay_reg_values - Computed io_reg configuration values (see TRM)
>> + * @coarse_ref_count:  Coarse reference count
>> + * @coarse_delay_count:        Coarse delay count
>> + * @fine_ref_count:    Fine reference count
>> + * @fine_delay_count:  Fine Delay count
>> + * @ref_clk_period:    Reference Clock period
>> + * @cdpe:              Coarse delay parameter
>> + * @fdpe:              Fine delay parameter
>> + */
>> +struct ti_iodelay_reg_values {
>> +       u16 coarse_ref_count;
>
> If you're doing reference counting, use kref.
> <linux/kref.h>
>
>> +       u16 coarse_delay_count;
>> +
>> +       u16 fine_ref_count;
>
> Dito.
>
>> +       u16 fine_delay_count;
>> +
>> +       u16 ref_clk_period;
>> +
>> +       u32 cdpe;
>> +       u32 fdpe;
>> +};
>
>
>> +/**
>> + * struct ti_iodelay_pin_name - name of the pins
>> + * @name: name
>> + */
>> +struct ti_iodelay_pin_name {
>> +       char name[IODELAY_REG_NAME_LEN];
>> +};
>
> What is this? The pin control subsystem already has a struct
> for naming pins. struct pinctrl_pin_desc.
>
> Are you reimplementing core functionality?
>
> The generic pin config reference pins by name, and since you
> obviously like to encode these into you data you can just
> as well use that method for this too.
>
> Again I think this is a side effect from using the pinctrl-single
> concepts, if you think of this as some other pinctrl driver
> I think this will fall out nicely.
>
>> +/**
>> + * struct ti_iodelay_device - Represents information for a IOdelay instance
>> + * @dev: device pointer
>> + * @reg_base: Remapped virtual address
>> + * @regmap: Regmap for this IOdelay instance
>> + * @pctl: Pinctrl device
>> + * @desc: pinctrl descriptor for pctl
>> + * @pa: pinctrl pin wise description
>> + * @names: names of the pins
>> + * @groups: list of pinconf groups for iodelay instance
>> + * @ngroups: number of groups in the list
>> + * @mutex: mutex to protect group list modification
>> + * @reg_data: Register definition data for the IODelay instance
>> + * @reg_init_conf_values: Initial configuration values.
>> + */
>> +struct ti_iodelay_device {
>> +       struct device *dev;
>> +       void __iomem *reg_base;
>> +       struct regmap *regmap;
>> +
>> +       struct pinctrl_dev *pctl;
>> +       struct pinctrl_desc desc;
>> +       struct pinctrl_pin_desc *pa;
>> +       struct ti_iodelay_pin_name *names;
>
> Unhappy about that. pinctrl_desc contains
> struct pinctrl_pin_desc const *pins; !
>
>> +
>> +       struct list_head groups;
>> +       int ngroups;
>> +       struct mutex mutex; /* list protection */
>
> Why is this needed? Usually the pin control core
> serialize calls into the drivers. Care to explain? Have
> the potential race really triggered?
>
>> +static inline u32 ti_iodelay_compute_dpe(u16 period, u16 ref, u16 delay,
>> +                                        u16 delay_m)
>> +{
>> +       u64 m, d;
>> +
>> +       /* Handle overflow conditions */
>> +       m = 10 * (u64)period * (u64)ref;
>> +       d = 2 * (u64)delay * (u64)delay_m;
>> +
>> +       /* Truncate result back to 32 bits */
>> +       return div64_u64(m, d);
>> +}
>
> Serious business ...
>
>> +/**
>> + * ti_iodelay_pinconf_set() - Configure the pin configuration
>> + * @iod:       IODelay device
>> + * @val:       Configuration value
>> + *
>> + * Update the configuration register as per TRM and lockup once done.
>> + * *IMPORTANT NOTE* SoC TRM does recommend doing iodelay programmation only
>> + * while in Isolation. But, then, isolation also implies that every pin
>> + * on the SoC(including DDR) will be isolated out. The only benefit being
>> + * a glitchless configuration, However, the intent of this driver is purely
>> + * to support a "glitchy" configuration where applicable.
>> + *
>> + * Return: 0 in case of success, else appropriate error value
>> + */
>> +static int ti_iodelay_pinconf_set(struct ti_iodelay_device *iod,
>> +                                 struct ti_iodelay_conf_vals *val)
>> +{
>> +       const struct ti_iodelay_reg_data *reg = iod->reg_data;
>> +       struct ti_iodelay_reg_values *ival = &iod->reg_init_conf_values;
>> +       struct device *dev = iod->dev;
>> +       u32 g_delay_coarse, g_delay_fine;
>> +       u32 a_delay_coarse, a_delay_fine;
>> +       u32 c_elements, f_elements;
>> +       u32 total_delay;
>> +       u32 reg_mask, reg_val, tmp_val;
>> +       int r;
>> +
>> +       /* NOTE: Truncation is expected in all division below */
>> +       g_delay_coarse = val->g_delay / 920;
>> +       g_delay_fine = ((val->g_delay % 920) * 10) / 60;
>> +
>> +       a_delay_coarse = val->a_delay / ival->cdpe;
>> +       a_delay_fine = ((val->a_delay % ival->cdpe) * 10) / ival->fdpe;
>> +
>> +       c_elements = g_delay_coarse + a_delay_coarse;
>> +       f_elements = (g_delay_fine + a_delay_fine) / 10;
>> +
>> +       if (f_elements > 22) {
>> +               total_delay = c_elements * ival->cdpe + f_elements * ival->fdpe;
>> +               c_elements = total_delay / ival->cdpe;
>> +               f_elements = (total_delay % ival->cdpe) / ival->fdpe;
>> +       }
>> +
>> +       reg_mask = reg->signature_mask;
>> +       reg_val = reg->signature_value << __ffs(reg->signature_mask);
>> +
>> +       reg_mask |= reg->binary_data_coarse_mask;
>> +       tmp_val = c_elements << __ffs(reg->binary_data_coarse_mask);
>> +       if (tmp_val & ~reg->binary_data_coarse_mask) {
>> +               dev_err(dev, "Masking overflow of coarse elements %08x\n",
>> +                       tmp_val);
>> +               tmp_val &= reg->binary_data_coarse_mask;
>> +       }
>> +       reg_val |= tmp_val;
>> +
>> +       reg_mask |= reg->binary_data_fine_mask;
>> +       tmp_val = f_elements << __ffs(reg->binary_data_fine_mask);
>> +       if (tmp_val & ~reg->binary_data_fine_mask) {
>> +               dev_err(dev, "Masking overflow of fine elements %08x\n",
>> +                       tmp_val);
>> +               tmp_val &= reg->binary_data_fine_mask;
>> +       }
>> +       reg_val |= tmp_val;
>> +
>> +       /* Write with lock value - we DONOT want h/w updates */
>> +       reg_mask |= reg->lock_mask;
>> +       reg_val |= reg->lock_val << __ffs(reg->lock_mask);
>> +       r = regmap_update_bits(iod->regmap, val->offset, reg_mask, reg_val);
>> +
>> +       dev_dbg(dev, "Set reg 0x%x Delay(a=%d g=%d), Elements(C=%d F=%d)0x%x\n",
>> +               val->offset, val->a_delay, val->g_delay, c_elements,
>> +               f_elements, reg_val);
>> +
>> +       return r;
>> +}
>
> Looking at this terse thing I think it's obviously easier to use
> a more verbose device tree description with
>
> drive-delay = <some SI unit>;
>
>
>> +       /* unlock the IOdelay region */
>> +       r = regmap_update_bits(iod->regmap, reg->reg_global_lock_offset,
>> +                              reg->global_lock_mask, reg->global_unlock_val);
>> +       if (r)
>> +               return r;
>> +
>> +       /* Read up Recalibration sequence done by bootloader */
>> +       r = regmap_read(iod->regmap, reg->reg_refclk_offset, &val);
>> +       if (r)
>> +               return r;
>> +       ival->ref_clk_period = ti_iodelay_extract(val, reg->refclk_period_mask);
>> +       dev_dbg(dev, "refclk_period=0x%04x\n", ival->ref_clk_period);
>
> That sounds hightec. So the bootloader calibrates the delays
> and  computes the refclock period? So is that sime PLL or something?
>
>> +       r = regmap_read(iod->regmap, reg->reg_coarse_offset, &val);
>> +       if (r)
>> +               return r;
>> +       ival->coarse_ref_count =
>> +           ti_iodelay_extract(val, reg->coarse_ref_count_mask);
>> +       ival->coarse_delay_count =
>> +           ti_iodelay_extract(val, reg->coarse_delay_count_mask);
>> +       if (!ival->coarse_delay_count) {
>> +               dev_err(dev, "Invalid Coarse delay count (0) (reg=0x%08x)\n",
>> +                       val);
>> +               return -EINVAL;
>> +       }
>> +       ival->cdpe = ti_iodelay_compute_dpe(ival->ref_clk_period,
>> +                                           ival->coarse_ref_count,
>> +                                           ival->coarse_delay_count, 88);
>
> 88? What does that mean... This should be #defined I think.
>
>> +static int ti_iodelay_dt_node_to_map(struct pinctrl_dev *pctldev,
>> +                                    struct device_node *np,
>> +                                    struct pinctrl_map **map,
>> +                                    unsigned *num_maps)
>
> If you use the generic bindings this quite complex parsing and
> everything associated with it goes away into the core.
>
>> +static void ti_iodelay_dt_free_map(struct pinctrl_dev *pctldev,
>> +                                  struct pinctrl_map *map, unsigned num_maps)
>
> Dito.
>
> BTW even if you proceed this way I suspect these are verbatim
> copies from pinctrl-single so they shold obviouslyt be abstracted
> out as library functions in that case.
>
>> +/**
>> + * ti_iodelay_pinctrl_get_group_pins() - get group pins
>> + * @pctldev:   pinctrl device representing IODelay device
>> + * @gselector: Group selector
>> + * @pins:      pointer to the pins
>> + * @npins:     number of pins
>> + *
>> + * Dummy implementation since we do not track pins, we track configurations
>> + * Forced by pinctrl's pinctrl_check_ops()
>> + *
>> + * Return: -EINVAL
>> + */
>> +static int ti_iodelay_pinctrl_get_group_pins(struct pinctrl_dev *pctldev,
>> +                                            unsigned gselector,
>> +                                            const unsigned **pins,
>> +                                            unsigned *npins)
>> +{
>> +       /* Dummy implementation - we dont do pin mux */
>> +       return -EINVAL;
>> +}
>
> This is not about muxing. It is about enumerating the pins in the
> group that will be affected by the setting, which is something you
> will want to do when using the generic bindings.
>
>> +       group = ti_iodelay_get_group(iod, gselector);
>
> And this seems to be your re-implementation of exactly that pin control
> core functionality. Which again should be shared with pinctrl-single if
> you anyway go down this path.
>
> I'll halt review here pending discussion on the bindings & stuff.

I assume we want to close on binding before looking at implementation
- definitely needs a rewrite - only guidance I'd probably need is
about which model you'd suggest I should follow(pinconf/pinctrl) once
we are done with the bindings discussion.

-- 
---
Regards,
Nishanth Menon