[PATCH v4 0/3] clk: meson: add a sub EMMC clock controller support

[PATCH v4 0/3] clk: meson: add a sub EMMC clock controller support

[Yixun Lan]

This driver will add a MMC clock controller driver support.
The original idea about adding a clock controller is during the
discussion in the NAND driver mainline effort[1].

This driver is tested in the S400 board (AXG platform) with NAND driver.

Changes since v3 [4]:
 - separate clk-phase-delay driver
 - replace clk_get_rate() with clk_hw_get_rate()
 - collect Rob's R-Y
 - drop 'meson-' prefix from compatible string

Changes since v2 [3]:
 - squash dt-binding clock-id patch
 - update license
 - fix alignment
 - construct a clk register helper() function

Changes since v1 [2]:
 - implement phase clock
 - update compatible name
 - adjust file name
 - divider probe() into small functions, and re-use them

[1] https://lkml.kernel.org/r/20180628090034.0637a062@xps13
[2] https://lkml.kernel.org/r/20180703145716.31860-1-yixun.lan@amlogic.com
[3] https://lkml.kernel.org/r/20180710163658.6175-1-yixun.lan@amlogic.com
[4] https://lkml.kernel.org/r/20180712211244.11428-1-yixun.lan@amlogic.com

Yixun Lan (3):
  clk: meson: add emmc sub clock phase delay driver
  clk: meson: add DT documentation for emmc clock controller
  clk: meson: add sub MMC clock controller driver

 .../bindings/clock/amlogic,mmc-clkc.txt       |  31 ++
 drivers/clk/meson/Kconfig                     |  10 +
 drivers/clk/meson/Makefile                    |   3 +-
 drivers/clk/meson/clk-phase-delay.c           |  96 ++++++
 drivers/clk/meson/clkc.h                      |  13 +
 drivers/clk/meson/mmc-clkc.c                  | 275 ++++++++++++++++++
 include/dt-bindings/clock/amlogic,mmc-clkc.h  |  17 ++
 7 files changed, 444 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/devicetree/bindings/clock/amlogic,mmc-clkc.txt
 create mode 100644 drivers/clk/meson/clk-phase-delay.c
 create mode 100644 drivers/clk/meson/mmc-clkc.c
 create mode 100644 include/dt-bindings/clock/amlogic,mmc-clkc.h

-- 
2.17.1

[PATCH v4 1/3] clk: meson: add emmc sub clock phase delay driver

[Yixun Lan]

Export the emmc sub clock phase delay ops which will be used
by the emmc sub clock driver itself.

Signed-off-by: Yixun Lan <yixun.lan@amlogic.com>
---
 drivers/clk/meson/Makefile          |  2 +-
 drivers/clk/meson/clk-phase-delay.c | 96 +++++++++++++++++++++++++++++
 drivers/clk/meson/clkc.h            | 13 ++++
 3 files changed, 110 insertions(+), 1 deletion(-)
 create mode 100644 drivers/clk/meson/clk-phase-delay.c

diff --git a/drivers/clk/meson/Makefile b/drivers/clk/meson/Makefile
index 72ec8c40d848..39ce5661b654 100644
--- a/drivers/clk/meson/Makefile
+++ b/drivers/clk/meson/Makefile
@@ -2,7 +2,7 @@
 # Makefile for Meson specific clk
 #
 
-obj-$(CONFIG_COMMON_CLK_AMLOGIC) += clk-pll.o clk-mpll.o clk-phase.o
+obj-$(CONFIG_COMMON_CLK_AMLOGIC) += clk-pll.o clk-mpll.o clk-phase.o clk-phase-delay.o
 obj-$(CONFIG_COMMON_CLK_AMLOGIC_AUDIO)	+= clk-triphase.o sclk-div.o
 obj-$(CONFIG_COMMON_CLK_MESON_AO) += meson-aoclk.o
 obj-$(CONFIG_COMMON_CLK_MESON8B) += meson8b.o
diff --git a/drivers/clk/meson/clk-phase-delay.c b/drivers/clk/meson/clk-phase-delay.c
new file mode 100644
index 000000000000..6f226814cfec
--- /dev/null
+++ b/drivers/clk/meson/clk-phase-delay.c
@@ -0,0 +1,96 @@
+// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+/*
+ * Amlogic Meson MMC Sub Clock Controller Driver
+ *
+ * Copyright (c) 2017 Baylibre SAS.
+ * Author: Jerome Brunet <jbrunet@baylibre.com>
+ *
+ * Copyright (c) 2018 Amlogic, inc.
+ * Author: Yixun Lan <yixun.lan@amlogic.com>
+ */
+
+#include <linux/clk-provider.h>
+#include "clkc.h"
+
+#define SD_EMMC_CLOCK			0
+
+static int meson_clk_phase_delay_get_phase(struct clk_hw *hw)
+{
+	struct clk_regmap *clk = to_clk_regmap(hw);
+	struct meson_clk_phase_delay_data *ph =
+		meson_clk_get_phase_delay_data(clk);
+	unsigned int phase_num = 1 <<  hweight_long(ph->phase_mask);
+	unsigned long period_ps, p, d;
+	int degrees;
+	u32 val;
+
+	regmap_read(clk->map, SD_EMMC_CLOCK, &val);
+	p = (val & ph->phase_mask) >> __ffs(ph->phase_mask);
+	degrees = p * 360 / phase_num;
+
+	if (ph->delay_mask) {
+		period_ps = DIV_ROUND_UP((unsigned long)NSEC_PER_SEC * 1000,
+					 clk_hw_get_rate(hw));
+		d = (val & ph->delay_mask) >> __ffs(ph->delay_mask);
+		degrees += d * ph->delay_step_ps * 360 / period_ps;
+		degrees %= 360;
+	}
+
+	return degrees;
+}
+
+static void meson_clk_apply_phase_delay(struct clk_regmap *clk,
+					unsigned int phase,
+					unsigned int delay)
+{
+	struct meson_clk_phase_delay_data *ph = clk->data;
+	u32 val;
+
+	regmap_read(clk->map, SD_EMMC_CLOCK, &val);
+
+	val &= ~ph->phase_mask;
+	val |= phase << __ffs(ph->phase_mask);
+
+	if (ph->delay_mask) {
+		val &= ~ph->delay_mask;
+		val |= delay << __ffs(ph->delay_mask);
+	}
+
+	regmap_write(clk->map, SD_EMMC_CLOCK, val);
+}
+
+static int meson_clk_phase_delay_set_phase(struct clk_hw *hw, int degrees)
+{
+	struct clk_regmap *clk = to_clk_regmap(hw);
+	struct meson_clk_phase_delay_data *ph =
+		meson_clk_get_phase_delay_data(clk);
+	unsigned int phase_num = 1 <<  hweight_long(ph->phase_mask);
+	unsigned long period_ps, d = 0, r;
+	u64 p;
+
+	p = degrees % 360;
+
+	if (!ph->delay_mask) {
+		p = DIV_ROUND_CLOSEST_ULL(p, 360 / phase_num);
+	} else {
+		period_ps = DIV_ROUND_UP((unsigned long)NSEC_PER_SEC * 1000,
+					 clk_hw_get_rate(hw));
+
+		/* First compute the phase index (p), the remainder (r) is the
+		 * part we'll try to acheive using the delays (d).
+		 */
+		r = do_div(p, 360 / phase_num);
+		d = DIV_ROUND_CLOSEST(r * period_ps,
+				      360 * ph->delay_step_ps);
+		d = min(d, ph->delay_mask >> __ffs(ph->delay_mask));
+	}
+
+	meson_clk_apply_phase_delay(clk, p, d);
+	return 0;
+}
+
+const struct clk_ops meson_clk_phase_delay_ops = {
+	.get_phase = meson_clk_phase_delay_get_phase,
+	.set_phase = meson_clk_phase_delay_set_phase,
+};
+EXPORT_SYMBOL_GPL(meson_clk_phase_delay_ops);
diff --git a/drivers/clk/meson/clkc.h b/drivers/clk/meson/clkc.h
index 24cec16b6038..499834dd34f2 100644
--- a/drivers/clk/meson/clkc.h
+++ b/drivers/clk/meson/clkc.h
@@ -113,6 +113,18 @@ struct clk_regmap _name = {						\
 	},								\
 };
 
+struct meson_clk_phase_delay_data {
+	unsigned long			phase_mask;
+	unsigned long			delay_mask;
+	unsigned int			delay_step_ps;
+};
+
+static inline struct meson_clk_phase_delay_data *
+meson_clk_get_phase_delay_data(struct clk_regmap *clk)
+{
+	return (struct meson_clk_phase_delay_data *)clk->data;
+}
+
 /* clk_ops */
 extern const struct clk_ops meson_clk_pll_ro_ops;
 extern const struct clk_ops meson_clk_pll_ops;
@@ -120,5 +132,6 @@ extern const struct clk_ops meson_clk_cpu_ops;
 extern const struct clk_ops meson_clk_mpll_ro_ops;
 extern const struct clk_ops meson_clk_mpll_ops;
 extern const struct clk_ops meson_clk_phase_ops;
+extern const struct clk_ops meson_clk_phase_delay_ops;
 
 #endif /* __CLKC_H */
-- 
2.17.1

[PATCH v4 2/3] clk: meson: add DT documentation for emmc clock controller

[Yixun Lan]

Document the MMC sub clock controller driver, the potential consumer
of this driver is MMC or NAND. Also add four clock bindings IDs which
provided by this driver.

Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Yixun Lan <yixun.lan@amlogic.com>
---
 .../bindings/clock/amlogic,mmc-clkc.txt       | 31 +++++++++++++++++++
 include/dt-bindings/clock/amlogic,mmc-clkc.h  | 17 ++++++++++
 2 files changed, 48 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/clock/amlogic,mmc-clkc.txt
 create mode 100644 include/dt-bindings/clock/amlogic,mmc-clkc.h

diff --git a/Documentation/devicetree/bindings/clock/amlogic,mmc-clkc.txt b/Documentation/devicetree/bindings/clock/amlogic,mmc-clkc.txt
new file mode 100644
index 000000000000..9e6d34389be8
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/amlogic,mmc-clkc.txt
@@ -0,0 +1,31 @@
+* Amlogic MMC Sub Clock Controller Driver
+
+The Amlogic MMC clock controller generates and supplies clock to support
+MMC and NAND controller
+
+Required Properties:
+
+- compatible: should be:
+		"amlogic,gx-mmc-clkc"
+		"amlogic,axg-mmc-clkc"
+
+- #clock-cells: should be 1.
+- clocks: phandles to clocks corresponding to the clock-names property
+- clock-names: list of parent clock names
+	- "clkin0", "clkin1"
+
+Parent node should have the following properties :
+- compatible: "amlogic,axg-mmc-clkc", "syscon".
+- reg: base address and size of the MMC control register space.
+
+Example: Clock controller node:
+
+sd_mmc_c_clkc: clock-controller@7000 {
+	compatible = "amlogic,axg-mmc-clkc", "syscon";
+	reg = <0x0 0x7000 0x0 0x4>;
+	#clock-cells = <1>;
+
+	clock-names = "clkin0", "clkin1";
+	clocks = <&clkc CLKID_SD_MMC_C_CLK0>,
+		 <&clkc CLKID_FCLK_DIV2>;
+};
diff --git a/include/dt-bindings/clock/amlogic,mmc-clkc.h b/include/dt-bindings/clock/amlogic,mmc-clkc.h
new file mode 100644
index 000000000000..162b94949119
--- /dev/null
+++ b/include/dt-bindings/clock/amlogic,mmc-clkc.h
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: (GPL-2.0+ OR MIT) */
+/*
+ * Meson MMC sub clock tree IDs
+ *
+ * Copyright (c) 2018 Amlogic, Inc. All rights reserved.
+ * Author: Yixun Lan <yixun.lan@amlogic.com>
+ */
+
+#ifndef __MMC_CLKC_H
+#define __MMC_CLKC_H
+
+#define CLKID_MMC_DIV				1
+#define CLKID_MMC_PHASE_CORE			2
+#define CLKID_MMC_PHASE_TX			3
+#define CLKID_MMC_PHASE_RX			4
+
+#endif
-- 
2.17.1

[PATCH v4 3/3] clk: meson: add sub MMC clock controller driver

[Yixun Lan]

The patch will add a MMC clock controller driver which used by MMC or NAND,
It provide a mux and divider clock, and three phase clocks - core, tx, tx.

Two clocks are provided as the parent of MMC clock controller from
upper layer clock controller - eg "amlogic,axg-clkc" in AXG platform.

To specify which clock the MMC or NAND driver may consume,
the preprocessor macros in the dt-bindings/clock/amlogic,mmc-clkc.h header
can be used in the device tree sources.

Signed-off-by: Yixun Lan <yixun.lan@amlogic.com>
---
 drivers/clk/meson/Kconfig    |  10 ++
 drivers/clk/meson/Makefile   |   1 +
 drivers/clk/meson/mmc-clkc.c | 275 +++++++++++++++++++++++++++++++++++
 3 files changed, 286 insertions(+)
 create mode 100644 drivers/clk/meson/mmc-clkc.c

diff --git a/drivers/clk/meson/Kconfig b/drivers/clk/meson/Kconfig
index efaa70f682b4..8b8ccbcfed1d 100644
--- a/drivers/clk/meson/Kconfig
+++ b/drivers/clk/meson/Kconfig
@@ -15,6 +15,16 @@ config COMMON_CLK_MESON_AO
 	select COMMON_CLK_REGMAP_MESON
 	select RESET_CONTROLLER
 
+config COMMON_CLK_MMC_MESON
+	tristate "Meson MMC Sub Clock Controller Driver"
+	depends on COMMON_CLK_AMLOGIC
+	select MFD_SYSCON
+	select REGMAP
+	help
+	  Support for the MMC sub clock controller on Amlogic Meson Platform,
+	  which include S905 (GXBB, GXL), A113D/X (AXG) devices.
+	  Say Y if you want this clock enabled.
+
 config COMMON_CLK_REGMAP_MESON
 	bool
 	select REGMAP
diff --git a/drivers/clk/meson/Makefile b/drivers/clk/meson/Makefile
index 39ce5661b654..31c16d524a4b 100644
--- a/drivers/clk/meson/Makefile
+++ b/drivers/clk/meson/Makefile
@@ -9,4 +9,5 @@ obj-$(CONFIG_COMMON_CLK_MESON8B) += meson8b.o
 obj-$(CONFIG_COMMON_CLK_GXBB)	 += gxbb.o gxbb-aoclk.o gxbb-aoclk-32k.o
 obj-$(CONFIG_COMMON_CLK_AXG)	 += axg.o axg-aoclk.o
 obj-$(CONFIG_COMMON_CLK_AXG_AUDIO)	+= axg-audio.o
+obj-$(CONFIG_COMMON_CLK_MMC_MESON) 	+= mmc-clkc.o
 obj-$(CONFIG_COMMON_CLK_REGMAP_MESON)	+= clk-regmap.o
diff --git a/drivers/clk/meson/mmc-clkc.c b/drivers/clk/meson/mmc-clkc.c
new file mode 100644
index 000000000000..6aa055f7e62c
--- /dev/null
+++ b/drivers/clk/meson/mmc-clkc.c
@@ -0,0 +1,275 @@
+// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+/*
+ * Amlogic Meson MMC Sub Clock Controller Driver
+ *
+ * Copyright (c) 2017 Baylibre SAS.
+ * Author: Jerome Brunet <jbrunet@baylibre.com>
+ *
+ * Copyright (c) 2018 Amlogic, inc.
+ * Author: Yixun Lan <yixun.lan@amlogic.com>
+ */
+
+#include <linux/clk.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/of_device.h>
+#include <linux/mfd/syscon.h>
+#include <linux/platform_device.h>
+#include <dt-bindings/clock/amlogic,mmc-clkc.h>
+
+#include "clkc.h"
+
+/* clock ID used by internal driver */
+#define CLKID_MMC_MUX			0
+
+#define SD_EMMC_CLOCK			0
+#define   CLK_DIV_MASK			GENMASK(5, 0)
+#define   CLK_SRC_MASK			GENMASK(7, 6)
+#define   CLK_CORE_PHASE_MASK		GENMASK(9, 8)
+#define   CLK_TX_PHASE_MASK		GENMASK(11, 10)
+#define   CLK_RX_PHASE_MASK		GENMASK(13, 12)
+#define   CLK_V2_TX_DELAY_MASK		GENMASK(19, 16)
+#define   CLK_V2_RX_DELAY_MASK		GENMASK(23, 20)
+#define   CLK_V2_ALWAYS_ON		BIT(24)
+
+#define   CLK_V3_TX_DELAY_MASK		GENMASK(21, 16)
+#define   CLK_V3_RX_DELAY_MASK		GENMASK(27, 22)
+#define   CLK_V3_ALWAYS_ON		BIT(28)
+
+#define   CLK_DELAY_STEP_PS		200
+#define   CLK_PHASE_STEP		30
+#define   CLK_PHASE_POINT_NUM		(360 / CLK_PHASE_STEP)
+
+#define MUX_CLK_NUM_PARENTS		2
+#define MMC_MAX_CLKS			5
+
+struct mmc_clkc_data {
+	struct meson_clk_phase_delay_data	tx;
+	struct meson_clk_phase_delay_data	rx;
+};
+
+static struct clk_regmap_mux_data mmc_clkc_mux_data = {
+	.offset		= SD_EMMC_CLOCK,
+	.mask		= 0x3,
+	.shift		= 6,
+	.flags		= CLK_DIVIDER_ROUND_CLOSEST,
+};
+
+static struct clk_regmap_div_data mmc_clkc_div_data = {
+	.offset		= SD_EMMC_CLOCK,
+	.shift		= 0,
+	.width		= 6,
+	.flags		= CLK_DIVIDER_ROUND_CLOSEST | CLK_DIVIDER_ONE_BASED,
+};
+
+static struct meson_clk_phase_delay_data mmc_clkc_core_phase_delay = {
+	.phase_mask	= CLK_CORE_PHASE_MASK,
+};
+
+static const struct mmc_clkc_data mmc_clkc_gx_data = {
+	{
+		.phase_mask	= CLK_TX_PHASE_MASK,
+		.delay_mask	= CLK_V2_TX_DELAY_MASK,
+		.delay_step_ps	= CLK_DELAY_STEP_PS,
+	},
+	{
+		.phase_mask	= CLK_RX_PHASE_MASK,
+		.delay_mask	= CLK_V2_RX_DELAY_MASK,
+		.delay_step_ps	= CLK_DELAY_STEP_PS,
+	},
+};
+
+static const struct mmc_clkc_data mmc_clkc_axg_data = {
+	{
+		.phase_mask	= CLK_TX_PHASE_MASK,
+		.delay_mask	= CLK_V3_TX_DELAY_MASK,
+		.delay_step_ps	= CLK_DELAY_STEP_PS,
+	},
+	{
+		.phase_mask	= CLK_RX_PHASE_MASK,
+		.delay_mask	= CLK_V3_RX_DELAY_MASK,
+		.delay_step_ps	= CLK_DELAY_STEP_PS,
+	},
+};
+
+static const struct of_device_id mmc_clkc_match_table[] = {
+	{
+		.compatible	= "amlogic,gx-mmc-clkc",
+		.data		= &mmc_clkc_gx_data
+	},
+	{
+		.compatible	= "amlogic,axg-mmc-clkc",
+		.data		= &mmc_clkc_axg_data
+	},
+	{}
+};
+MODULE_DEVICE_TABLE(of, mmc_clkc_match_table);
+
+static struct clk_regmap *
+mmc_clkc_register_clk(struct device *dev, struct regmap *map,
+		      struct clk_init_data *init,
+		      const char *suffix, void *data)
+{
+	struct clk_regmap *clk;
+	char *name;
+	int ret;
+
+	clk = devm_kzalloc(dev, sizeof(*clk), GFP_KERNEL);
+	if (!clk)
+		return ERR_PTR(-ENOMEM);
+
+	name = kasprintf(GFP_KERNEL, "%s#%s", dev_name(dev), suffix);
+	if (!name)
+		return ERR_PTR(-ENOMEM);
+
+	init->name = name;
+
+	clk->map = map;
+	clk->data = data;
+	clk->hw.init = init;
+
+	ret = devm_clk_hw_register(dev, &clk->hw);
+	if (ret)
+		clk = ERR_PTR(ret);
+
+	kfree(name);
+	return clk;
+}
+
+static struct clk_regmap *mmc_clkc_register_mux(struct device *dev,
+						struct regmap *map)
+{
+	const char *parent_names[MUX_CLK_NUM_PARENTS];
+	struct clk_init_data init;
+	struct clk_regmap *mux;
+	struct clk *clk;
+	int i;
+
+	for (i = 0; i < MUX_CLK_NUM_PARENTS; i++) {
+		char name[8];
+
+		snprintf(name, sizeof(name), "clkin%d", i);
+		clk = devm_clk_get(dev, name);
+		if (IS_ERR(clk)) {
+			if (clk != ERR_PTR(-EPROBE_DEFER))
+				dev_err(dev, "Missing clock %s\n", name);
+			return ERR_PTR((long)clk);
+		}
+
+		parent_names[i] = __clk_get_name(clk);
+	}
+
+	init.ops = &clk_regmap_mux_ops;
+	init.flags = CLK_SET_RATE_PARENT;
+	init.parent_names = parent_names;
+	init.num_parents = MUX_CLK_NUM_PARENTS;
+
+	mux = mmc_clkc_register_clk(dev, map, &init, "mux", &mmc_clkc_mux_data);
+	if (IS_ERR(mux))
+		dev_err(dev, "Mux clock registration failed\n");
+
+	return mux;
+}
+
+static struct clk_regmap *
+mmc_clkc_register_other_clk(struct device *dev, struct regmap *map,
+			    char *suffix, char *parent_suffix,
+			    unsigned long flags,
+			    const struct clk_ops *ops, void *data)
+{
+	struct clk_init_data init;
+	struct clk_regmap *clk;
+	char *parent;
+
+	parent = kasprintf(GFP_KERNEL, "%s#%s", dev_name(dev), parent_suffix);
+	if (!parent)
+		return ERR_PTR(-ENOMEM);
+
+	init.ops = ops;
+	init.flags = flags;
+	init.parent_names = (const char* const []){ parent, };
+	init.num_parents = 1;
+
+	clk = mmc_clkc_register_clk(dev, map, &init, suffix, data);
+	if (IS_ERR(clk))
+		dev_err(dev, "Core %s clock registration failed\n", suffix);
+
+	kfree(parent);
+	return clk;
+}
+
+static int mmc_clkc_probe(struct platform_device *pdev)
+{
+	struct clk_hw_onecell_data *onecell_data;
+	struct device *dev = &pdev->dev;
+	struct mmc_clkc_data *data;
+	struct regmap *map;
+	struct clk_regmap *mux, *div, *core, *rx, *tx;
+
+	data = (struct mmc_clkc_data *)of_device_get_match_data(dev);
+	if (!data)
+		return -ENODEV;
+
+	map = syscon_node_to_regmap(dev->of_node);
+	if (IS_ERR(map)) {
+		dev_err(dev, "could not find mmc clock controller\n");
+		return PTR_ERR(map);
+	}
+
+	onecell_data = devm_kzalloc(dev, sizeof(*onecell_data) +
+				    sizeof(*onecell_data->hws) * MMC_MAX_CLKS,
+				    GFP_KERNEL);
+	if (!onecell_data)
+		return -ENOMEM;
+
+	mux = mmc_clkc_register_mux(dev, map);
+	if (IS_ERR(mux))
+		return PTR_ERR(mux);
+
+	div = mmc_clkc_register_other_clk(dev, map, "div", "mux",
+					  CLK_SET_RATE_PARENT,
+					  &clk_regmap_divider_ops,
+					  &mmc_clkc_div_data);
+	if (IS_ERR(div))
+		return PTR_ERR(div);
+
+	core = mmc_clkc_register_other_clk(dev, map, "core", "div",
+					   CLK_SET_RATE_PARENT,
+					   &meson_clk_phase_delay_ops,
+					   &mmc_clkc_core_phase_delay);
+	if (IS_ERR(core))
+		return PTR_ERR(core);
+
+	rx = mmc_clkc_register_other_clk(dev, map, "rx", "core", 0,
+					 &meson_clk_phase_delay_ops,
+					 &data->rx);
+	if (IS_ERR(rx))
+		return PTR_ERR(rx);
+
+	tx = mmc_clkc_register_other_clk(dev, map, "tx", "core", 0,
+					 &meson_clk_phase_delay_ops,
+					 &data->tx);
+	if (IS_ERR(tx))
+		return PTR_ERR(tx);
+
+	onecell_data->hws[CLKID_MMC_MUX]		= &mux->hw,
+	onecell_data->hws[CLKID_MMC_DIV]		= &div->hw,
+	onecell_data->hws[CLKID_MMC_PHASE_CORE]		= &core->hw,
+	onecell_data->hws[CLKID_MMC_PHASE_RX]		= &rx->hw,
+	onecell_data->hws[CLKID_MMC_PHASE_TX]		= &tx->hw,
+	onecell_data->num				= MMC_MAX_CLKS;
+
+	return devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get,
+					   onecell_data);
+}
+
+static struct platform_driver mmc_clkc_driver = {
+	.probe		= mmc_clkc_probe,
+	.driver		= {
+		.name	= "meson-mmc-clkc",
+		.of_match_table = of_match_ptr(mmc_clkc_match_table),
+	},
+};
+
+module_platform_driver(mmc_clkc_driver);
-- 
2.17.1

Re: [PATCH v4 1/3] clk: meson: add emmc sub clock phase delay driver

[Jerome Brunet]

On Thu, 2018-08-09 at 15:07 +0800, Yixun Lan wrote:
> Export the emmc sub clock phase delay ops which will be used
> by the emmc sub clock driver itself.
> 
> Signed-off-by: Yixun Lan <yixun.lan@amlogic.com>
> ---
>  drivers/clk/meson/Makefile          |  2 +-
>  drivers/clk/meson/clk-phase-delay.c | 96 +++++++++++++++++++++++++++++
>  drivers/clk/meson/clkc.h            | 13 ++++
>  3 files changed, 110 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/clk/meson/clk-phase-delay.c
> 
> diff --git a/drivers/clk/meson/Makefile b/drivers/clk/meson/Makefile
> index 72ec8c40d848..39ce5661b654 100644
> --- a/drivers/clk/meson/Makefile
> +++ b/drivers/clk/meson/Makefile
> @@ -2,7 +2,7 @@
>  # Makefile for Meson specific clk
>  #
>  
> -obj-$(CONFIG_COMMON_CLK_AMLOGIC) += clk-pll.o clk-mpll.o clk-phase.o
> +obj-$(CONFIG_COMMON_CLK_AMLOGIC) += clk-pll.o clk-mpll.o clk-phase.o clk-phase-delay.o
>  obj-$(CONFIG_COMMON_CLK_AMLOGIC_AUDIO)	+= clk-triphase.o sclk-div.o
>  obj-$(CONFIG_COMMON_CLK_MESON_AO) += meson-aoclk.o
>  obj-$(CONFIG_COMMON_CLK_MESON8B) += meson8b.o
> diff --git a/drivers/clk/meson/clk-phase-delay.c b/drivers/clk/meson/clk-phase-delay.c
> new file mode 100644
> index 000000000000..6f226814cfec
> --- /dev/null
> +++ b/drivers/clk/meson/clk-phase-delay.c
> @@ -0,0 +1,96 @@
> +// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
> +/*
> + * Amlogic Meson MMC Sub Clock Controller Driver
> + *
> + * Copyright (c) 2017 Baylibre SAS.
> + * Author: Jerome Brunet <jbrunet@baylibre.com>
> + *
> + * Copyright (c) 2018 Amlogic, inc.
> + * Author: Yixun Lan <yixun.lan@amlogic.com>
> + */
> +
> +#include <linux/clk-provider.h>
> +#include "clkc.h"
> +
> +#define SD_EMMC_CLOCK			0

Drop this and use struct parm please.

> +
> +static int meson_clk_phase_delay_get_phase(struct clk_hw *hw)
> +{
> +	struct clk_regmap *clk = to_clk_regmap(hw);
> +	struct meson_clk_phase_delay_data *ph =
> +		meson_clk_get_phase_delay_data(clk);
> +	unsigned int phase_num = 1 <<  hweight_long(ph->phase_mask);
> +	unsigned long period_ps, p, d;
> +	int degrees;
> +	u32 val;
> +
> +	regmap_read(clk->map, SD_EMMC_CLOCK, &val);
> +	p = (val & ph->phase_mask) >> __ffs(ph->phase_mask);
> +	degrees = p * 360 / phase_num;
> +
> +	if (ph->delay_mask) {
> +		period_ps = DIV_ROUND_UP((unsigned long)NSEC_PER_SEC * 1000,
> +					 clk_hw_get_rate(hw));
> +		d = (val & ph->delay_mask) >> __ffs(ph->delay_mask);
> +		degrees += d * ph->delay_step_ps * 360 / period_ps;
> +		degrees %= 360;
> +	}
> +
> +	return degrees;
> +}
> +
> +static void meson_clk_apply_phase_delay(struct clk_regmap *clk,
> +					unsigned int phase,
> +					unsigned int delay)
> +{
> +	struct meson_clk_phase_delay_data *ph = clk->data;
> +	u32 val;
> +
> +	regmap_read(clk->map, SD_EMMC_CLOCK, &val);
> +
> +	val &= ~ph->phase_mask;
> +	val |= phase << __ffs(ph->phase_mask);
> +
> +	if (ph->delay_mask) {

This imply that delay is delay is optional. In such case, it would be a regular
"phase" and we already have a  driver for this. Please remove all the related
code and make this parameter required for this clock type.

In the future, maybe we'll merge the 2 drivers.

> +		val &= ~ph->delay_mask;
> +		val |= delay << __ffs(ph->delay_mask);
> +	}
> +
> +	regmap_write(clk->map, SD_EMMC_CLOCK, val);
> +}
> +
> +static int meson_clk_phase_delay_set_phase(struct clk_hw *hw, int degrees)
> +{
> +	struct clk_regmap *clk = to_clk_regmap(hw);
> +	struct meson_clk_phase_delay_data *ph =
> +		meson_clk_get_phase_delay_data(clk);
> +	unsigned int phase_num = 1 <<  hweight_long(ph->phase_mask);
> +	unsigned long period_ps, d = 0, r;
> +	u64 p;
> +
> +	p = degrees % 360;
> +
> +	if (!ph->delay_mask) {
> +		p = DIV_ROUND_CLOSEST_ULL(p, 360 / phase_num);
> +	} else {
> +		period_ps = DIV_ROUND_UP((unsigned long)NSEC_PER_SEC * 1000,
> +					 clk_hw_get_rate(hw));
> +
> +		/* First compute the phase index (p), the remainder (r) is the
> +		 * part we'll try to acheive using the delays (d).
> +		 */
> +		r = do_div(p, 360 / phase_num);
> +		d = DIV_ROUND_CLOSEST(r * period_ps,
> +				      360 * ph->delay_step_ps);
> +		d = min(d, ph->delay_mask >> __ffs(ph->delay_mask));
> +	}
> +
> +	meson_clk_apply_phase_delay(clk, p, d);
> +	return 0;
> +}
> +
> +const struct clk_ops meson_clk_phase_delay_ops = {
> +	.get_phase = meson_clk_phase_delay_get_phase,
> +	.set_phase = meson_clk_phase_delay_set_phase,
> +};
> +EXPORT_SYMBOL_GPL(meson_clk_phase_delay_ops);
> diff --git a/drivers/clk/meson/clkc.h b/drivers/clk/meson/clkc.h
> index 24cec16b6038..499834dd34f2 100644
> --- a/drivers/clk/meson/clkc.h
> +++ b/drivers/clk/meson/clkc.h
> @@ -113,6 +113,18 @@ struct clk_regmap _name = {						\
>  	},								\
>  };
>  
> +struct meson_clk_phase_delay_data {
> +	unsigned long			phase_mask;
> +	unsigned long			delay_mask;

Like every other clock drivers in the amlogic directory, please use struct parm
to decribe the fields.

> +	unsigned int			delay_step_ps;
> +};
> +
> +static inline struct meson_clk_phase_delay_data *
> +meson_clk_get_phase_delay_data(struct clk_regmap *clk)
> +{
> +	return (struct meson_clk_phase_delay_data *)clk->data;
> +}
> +
>  /* clk_ops */
>  extern const struct clk_ops meson_clk_pll_ro_ops;
>  extern const struct clk_ops meson_clk_pll_ops;
> @@ -120,5 +132,6 @@ extern const struct clk_ops meson_clk_cpu_ops;
>  extern const struct clk_ops meson_clk_mpll_ro_ops;
>  extern const struct clk_ops meson_clk_mpll_ops;
>  extern const struct clk_ops meson_clk_phase_ops;
> +extern const struct clk_ops meson_clk_phase_delay_ops;
>  
>  #endif /* __CLKC_H */

Re: [PATCH v4 3/3] clk: meson: add sub MMC clock controller driver

[Jerome Brunet]

On Thu, 2018-08-09 at 15:07 +0800, Yixun Lan wrote:
> The patch will add a MMC clock controller driver which used by MMC or NAND,
> It provide a mux and divider clock, and three phase clocks - core, tx, tx.
> 
> Two clocks are provided as the parent of MMC clock controller from
> upper layer clock controller - eg "amlogic,axg-clkc" in AXG platform.
> 
> To specify which clock the MMC or NAND driver may consume,
> the preprocessor macros in the dt-bindings/clock/amlogic,mmc-clkc.h header
> can be used in the device tree sources.
> 
> Signed-off-by: Yixun Lan <yixun.lan@amlogic.com>
> ---
>  drivers/clk/meson/Kconfig    |  10 ++
>  drivers/clk/meson/Makefile   |   1 +
>  drivers/clk/meson/mmc-clkc.c | 275 +++++++++++++++++++++++++++++++++++
>  3 files changed, 286 insertions(+)
>  create mode 100644 drivers/clk/meson/mmc-clkc.c
> 
> diff --git a/drivers/clk/meson/Kconfig b/drivers/clk/meson/Kconfig
> index efaa70f682b4..8b8ccbcfed1d 100644
> --- a/drivers/clk/meson/Kconfig
> +++ b/drivers/clk/meson/Kconfig
> @@ -15,6 +15,16 @@ config COMMON_CLK_MESON_AO
>  	select COMMON_CLK_REGMAP_MESON
>  	select RESET_CONTROLLER
>  
> +config COMMON_CLK_MMC_MESON
> +	tristate "Meson MMC Sub Clock Controller Driver"
> +	depends on COMMON_CLK_AMLOGIC
> +	select MFD_SYSCON
> +	select REGMAP
> +	help
> +	  Support for the MMC sub clock controller on Amlogic Meson Platform,
> +	  which include S905 (GXBB, GXL), A113D/X (AXG) devices.
> +	  Say Y if you want this clock enabled.
> +
>  config COMMON_CLK_REGMAP_MESON
>  	bool
>  	select REGMAP
> diff --git a/drivers/clk/meson/Makefile b/drivers/clk/meson/Makefile
> index 39ce5661b654..31c16d524a4b 100644
> --- a/drivers/clk/meson/Makefile
> +++ b/drivers/clk/meson/Makefile
> @@ -9,4 +9,5 @@ obj-$(CONFIG_COMMON_CLK_MESON8B) += meson8b.o
>  obj-$(CONFIG_COMMON_CLK_GXBB)	 += gxbb.o gxbb-aoclk.o gxbb-aoclk-32k.o
>  obj-$(CONFIG_COMMON_CLK_AXG)	 += axg.o axg-aoclk.o
>  obj-$(CONFIG_COMMON_CLK_AXG_AUDIO)	+= axg-audio.o
> +obj-$(CONFIG_COMMON_CLK_MMC_MESON) 	+= mmc-clkc.o
>  obj-$(CONFIG_COMMON_CLK_REGMAP_MESON)	+= clk-regmap.o
> diff --git a/drivers/clk/meson/mmc-clkc.c b/drivers/clk/meson/mmc-clkc.c
> new file mode 100644
> index 000000000000..6aa055f7e62c
> --- /dev/null
> +++ b/drivers/clk/meson/mmc-clkc.c
> @@ -0,0 +1,275 @@
> +// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
> +/*
> + * Amlogic Meson MMC Sub Clock Controller Driver
> + *
> + * Copyright (c) 2017 Baylibre SAS.
> + * Author: Jerome Brunet <jbrunet@baylibre.com>
> + *
> + * Copyright (c) 2018 Amlogic, inc.
> + * Author: Yixun Lan <yixun.lan@amlogic.com>
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/module.h>
> +#include <linux/regmap.h>
> +#include <linux/slab.h>
> +#include <linux/of_device.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/platform_device.h>
> +#include <dt-bindings/clock/amlogic,mmc-clkc.h>
> +
> +#include "clkc.h"
> +
> +/* clock ID used by internal driver */
> +#define CLKID_MMC_MUX			0
> +
> +#define SD_EMMC_CLOCK			0
> +#define   CLK_DIV_MASK			GENMASK(5, 0)
> +#define   CLK_SRC_MASK			GENMASK(7, 6)
> +#define   CLK_CORE_PHASE_MASK		GENMASK(9, 8)
> +#define   CLK_TX_PHASE_MASK		GENMASK(11, 10)
> +#define   CLK_RX_PHASE_MASK		GENMASK(13, 12)
> +#define   CLK_V2_TX_DELAY_MASK		GENMASK(19, 16)
> +#define   CLK_V2_RX_DELAY_MASK		GENMASK(23, 20)
> +#define   CLK_V2_ALWAYS_ON		BIT(24)
> +
> +#define   CLK_V3_TX_DELAY_MASK		GENMASK(21, 16)
> +#define   CLK_V3_RX_DELAY_MASK		GENMASK(27, 22)
> +#define   CLK_V3_ALWAYS_ON		BIT(28)
> +
> +#define   CLK_DELAY_STEP_PS		200
> +#define   CLK_PHASE_STEP		30
> +#define   CLK_PHASE_POINT_NUM		(360 / CLK_PHASE_STEP)
> +
> +#define MUX_CLK_NUM_PARENTS		2
> +#define MMC_MAX_CLKS			5
> +
> +struct mmc_clkc_data {
> +	struct meson_clk_phase_delay_data	tx;
> +	struct meson_clk_phase_delay_data	rx;
> +};
> +
> +static struct clk_regmap_mux_data mmc_clkc_mux_data = {
> +	.offset		= SD_EMMC_CLOCK,
> +	.mask		= 0x3,
> +	.shift		= 6,
> +	.flags		= CLK_DIVIDER_ROUND_CLOSEST,
> +};
> +
> +static struct clk_regmap_div_data mmc_clkc_div_data = {
> +	.offset		= SD_EMMC_CLOCK,
> +	.shift		= 0,
> +	.width		= 6,
> +	.flags		= CLK_DIVIDER_ROUND_CLOSEST | CLK_DIVIDER_ONE_BASED,
> +};
> +
> +static struct meson_clk_phase_delay_data mmc_clkc_core_phase_delay = {
> +	.phase_mask	= CLK_CORE_PHASE_MASK,
> +};
> +
> +static const struct mmc_clkc_data mmc_clkc_gx_data = {
> +	{
> +		.phase_mask	= CLK_TX_PHASE_MASK,
> +		.delay_mask	= CLK_V2_TX_DELAY_MASK,
> +		.delay_step_ps	= CLK_DELAY_STEP_PS,
> +	},
> +	{
> +		.phase_mask	= CLK_RX_PHASE_MASK,
> +		.delay_mask	= CLK_V2_RX_DELAY_MASK,
> +		.delay_step_ps	= CLK_DELAY_STEP_PS,
> +	},
> +};
> +
> +static const struct mmc_clkc_data mmc_clkc_axg_data = {
> +	{
> +		.phase_mask	= CLK_TX_PHASE_MASK,
> +		.delay_mask	= CLK_V3_TX_DELAY_MASK,
> +		.delay_step_ps	= CLK_DELAY_STEP_PS,
> +	},
> +	{
> +		.phase_mask	= CLK_RX_PHASE_MASK,
> +		.delay_mask	= CLK_V3_RX_DELAY_MASK,
> +		.delay_step_ps	= CLK_DELAY_STEP_PS,
> +	},
> +};
> +
> +static const struct of_device_id mmc_clkc_match_table[] = {
> +	{
> +		.compatible	= "amlogic,gx-mmc-clkc",
> +		.data		= &mmc_clkc_gx_data
> +	},
> +	{
> +		.compatible	= "amlogic,axg-mmc-clkc",
> +		.data		= &mmc_clkc_axg_data
> +	},
> +	{}
> +};
> +MODULE_DEVICE_TABLE(of, mmc_clkc_match_table);
> +
> +static struct clk_regmap *
> +mmc_clkc_register_clk(struct device *dev, struct regmap *map,
> +		      struct clk_init_data *init,
> +		      const char *suffix, void *data)
> +{
> +	struct clk_regmap *clk;
> +	char *name;
> +	int ret;
> +
> +	clk = devm_kzalloc(dev, sizeof(*clk), GFP_KERNEL);
> +	if (!clk)
> +		return ERR_PTR(-ENOMEM);
> +
> +	name = kasprintf(GFP_KERNEL, "%s#%s", dev_name(dev), suffix);
> +	if (!name)
> +		return ERR_PTR(-ENOMEM);
> +
> +	init->name = name;
> +
> +	clk->map = map;
> +	clk->data = data;
> +	clk->hw.init = init;
> +
> +	ret = devm_clk_hw_register(dev, &clk->hw);
> +	if (ret)
> +		clk = ERR_PTR(ret);
> +
> +	kfree(name);
> +	return clk;
> +}
> +
> +static struct clk_regmap *mmc_clkc_register_mux(struct device *dev,
> +						struct regmap *map)
> +{
> +	const char *parent_names[MUX_CLK_NUM_PARENTS];
> +	struct clk_init_data init;
> +	struct clk_regmap *mux;
> +	struct clk *clk;
> +	int i;
> +
> +	for (i = 0; i < MUX_CLK_NUM_PARENTS; i++) {
> +		char name[8];
> +
> +		snprintf(name, sizeof(name), "clkin%d", i);
> +		clk = devm_clk_get(dev, name);
> +		if (IS_ERR(clk)) {
> +			if (clk != ERR_PTR(-EPROBE_DEFER))
> +				dev_err(dev, "Missing clock %s\n", name);
> +			return ERR_PTR((long)clk);
> +		}
> +
> +		parent_names[i] = __clk_get_name(clk);
> +	}
> +
> +	init.ops = &clk_regmap_mux_ops;
> +	init.flags = CLK_SET_RATE_PARENT;
> +	init.parent_names = parent_names;
> +	init.num_parents = MUX_CLK_NUM_PARENTS;
> +
> +	mux = mmc_clkc_register_clk(dev, map, &init, "mux", &mmc_clkc_mux_data);
> +	if (IS_ERR(mux))
> +		dev_err(dev, "Mux clock registration failed\n");
> +
> +	return mux;
> +}
> +
> +static struct clk_regmap *
> +mmc_clkc_register_other_clk(struct device *dev, struct regmap *map,

This is a poor name. It does not help understand what the function does.
mmc_clkc_register_clk_with_parent or whatever helps understand what's going on

> +			    char *suffix, char *parent_suffix,

You should not have to rebuild the parent name once again.
Pass the clk_hw* of the parent and get the name from it.

> +			    unsigned long flags,
> +			    const struct clk_ops *ops, void *data)
> +{
> +	struct clk_init_data init;
> +	struct clk_regmap *clk;
> +	char *parent;
> +
> +	parent = kasprintf(GFP_KERNEL, "%s#%s", dev_name(dev), parent_suffix);
> +	if (!parent)
> +		return ERR_PTR(-ENOMEM);
> +
> +	init.ops = ops;
> +	init.flags = flags;
> +	init.parent_names = (const char* const []){ parent, };
> +	init.num_parents = 1;
> +
> +	clk = mmc_clkc_register_clk(dev, map, &init, suffix, data);
> +	if (IS_ERR(clk))
> +		dev_err(dev, "Core %s clock registration failed\n", suffix);
> +
> +	kfree(parent);
> +	return clk;
> +}
> +
> +static int mmc_clkc_probe(struct platform_device *pdev)
> +{
> +	struct clk_hw_onecell_data *onecell_data;
> +	struct device *dev = &pdev->dev;
> +	struct mmc_clkc_data *data;
> +	struct regmap *map;
> +	struct clk_regmap *mux, *div, *core, *rx, *tx;

Do you really need all this ? or could store them in your onecell_data->hws
table as you go ?

> +
> +	data = (struct mmc_clkc_data *)of_device_get_match_data(dev);
> +	if (!data)
> +		return -ENODEV;
> +
> +	map = syscon_node_to_regmap(dev->of_node);
> +	if (IS_ERR(map)) {
> +		dev_err(dev, "could not find mmc clock controller\n");
> +		return PTR_ERR(map);
> +	}
> +
> +	onecell_data = devm_kzalloc(dev, sizeof(*onecell_data) +
> +				    sizeof(*onecell_data->hws) * MMC_MAX_CLKS,
> +				    GFP_KERNEL);
> +	if (!onecell_data)
> +		return -ENOMEM;
> +
> +	mux = mmc_clkc_register_mux(dev, map);
> +	if (IS_ERR(mux))
> +		return PTR_ERR(mux);
> +
> +	div = mmc_clkc_register_other_clk(dev, map, "div", "mux",
> +					  CLK_SET_RATE_PARENT,
> +					  &clk_regmap_divider_ops,
> +					  &mmc_clkc_div_data);
> +	if (IS_ERR(div))
> +		return PTR_ERR(div);
> +
> +	core = mmc_clkc_register_other_clk(dev, map, "core", "div",
> +					   CLK_SET_RATE_PARENT,
> +					   &meson_clk_phase_delay_ops,
> +					   &mmc_clkc_core_phase_delay);
> +	if (IS_ERR(core))
> +		return PTR_ERR(core);
> +
> +	rx = mmc_clkc_register_other_clk(dev, map, "rx", "core", 0,
> +					 &meson_clk_phase_delay_ops,
> +					 &data->rx);
> +	if (IS_ERR(rx))
> +		return PTR_ERR(rx);
> +
> +	tx = mmc_clkc_register_other_clk(dev, map, "tx", "core", 0,
> +					 &meson_clk_phase_delay_ops,
> +					 &data->tx);
> +	if (IS_ERR(tx))
> +		return PTR_ERR(tx);
> +
> +	onecell_data->hws[CLKID_MMC_MUX]		= &mux->hw,
> +	onecell_data->hws[CLKID_MMC_DIV]		= &div->hw,
> +	onecell_data->hws[CLKID_MMC_PHASE_CORE]		= &core->hw,
> +	onecell_data->hws[CLKID_MMC_PHASE_RX]		= &rx->hw,
> +	onecell_data->hws[CLKID_MMC_PHASE_TX]		= &tx->hw,
> +	onecell_data->num				= MMC_MAX_CLKS;
> +
> +	return devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get,
> +					   onecell_data);
> +}
> +
> +static struct platform_driver mmc_clkc_driver = {
> +	.probe		= mmc_clkc_probe,
> +	.driver		= {
> +		.name	= "meson-mmc-clkc",
> +		.of_match_table = of_match_ptr(mmc_clkc_match_table),
> +	},
> +};
> +
> +module_platform_driver(mmc_clkc_driver);

Re: [PATCH v4 1/3] clk: meson: add emmc sub clock phase delay driver

[Jianxin Pan]

Hi Jerome,

Sorry to miss this mail. I thought Yixun has finished this patchset. 
I will continue his work.

On 2018/8/10 20:27, Jerome Brunet wrote:
> On Thu, 2018-08-09 at 15:07 +0800, Yixun Lan wrote:
>> Export the emmc sub clock phase delay ops which will be used
>> by the emmc sub clock driver itself.
>>
>> Signed-off-by: Yixun Lan <yixun.lan@amlogic.com>
>> ---
>>  drivers/clk/meson/Makefile          |  2 +-
>>  drivers/clk/meson/clk-phase-delay.c | 96 +++++++++++++++++++++++++++++
>>  drivers/clk/meson/clkc.h            | 13 ++++
>>  3 files changed, 110 insertions(+), 1 deletion(-)
>>  create mode 100644 drivers/clk/meson/clk-phase-delay.c
>>
>> diff --git a/drivers/clk/meson/Makefile b/drivers/clk/meson/Makefile
>> index 72ec8c40d848..39ce5661b654 100644
>> --- a/drivers/clk/meson/Makefile
>> +++ b/drivers/clk/meson/Makefile
>> @@ -2,7 +2,7 @@
>>  # Makefile for Meson specific clk
>>  #
>>  
>> -obj-$(CONFIG_COMMON_CLK_AMLOGIC) += clk-pll.o clk-mpll.o clk-phase.o
>> +obj-$(CONFIG_COMMON_CLK_AMLOGIC) += clk-pll.o clk-mpll.o clk-phase.o clk-phase-delay.o
>>  obj-$(CONFIG_COMMON_CLK_AMLOGIC_AUDIO)	+= clk-triphase.o sclk-div.o
>>  obj-$(CONFIG_COMMON_CLK_MESON_AO) += meson-aoclk.o
>>  obj-$(CONFIG_COMMON_CLK_MESON8B) += meson8b.o
>> diff --git a/drivers/clk/meson/clk-phase-delay.c b/drivers/clk/meson/clk-phase-delay.c
>> new file mode 100644
>> index 000000000000..6f226814cfec
>> --- /dev/null
>> +++ b/drivers/clk/meson/clk-phase-delay.c
>> @@ -0,0 +1,96 @@
>> +// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
>> +/*
>> + * Amlogic Meson MMC Sub Clock Controller Driver
>> + *
>> + * Copyright (c) 2017 Baylibre SAS.
>> + * Author: Jerome Brunet <jbrunet@baylibre.com>
>> + *
>> + * Copyright (c) 2018 Amlogic, inc.
>> + * Author: Yixun Lan <yixun.lan@amlogic.com>
>> + */
>> +
>> +#include <linux/clk-provider.h>
>> +#include "clkc.h"
>> +
>> +#define SD_EMMC_CLOCK			0
> 
> Drop this and use struct parm please.
> 
OK. I will use struct parm instead. Thanks for your time.
>> +
>> +static int meson_clk_phase_delay_get_phase(struct clk_hw *hw)
>> +{
>> +	struct clk_regmap *clk = to_clk_regmap(hw);
>> +	struct meson_clk_phase_delay_data *ph =
>> +		meson_clk_get_phase_delay_data(clk);
>> +	unsigned int phase_num = 1 <<  hweight_long(ph->phase_mask);
>> +	unsigned long period_ps, p, d;
>> +	int degrees;
>> +	u32 val;
>> +
>> +	regmap_read(clk->map, SD_EMMC_CLOCK, &val);
>> +	p = (val & ph->phase_mask) >> __ffs(ph->phase_mask);
>> +	degrees = p * 360 / phase_num;
>> +
>> +	if (ph->delay_mask) {
>> +		period_ps = DIV_ROUND_UP((unsigned long)NSEC_PER_SEC * 1000,
>> +					 clk_hw_get_rate(hw));
>> +		d = (val & ph->delay_mask) >> __ffs(ph->delay_mask);
>> +		degrees += d * ph->delay_step_ps * 360 / period_ps;
>> +		degrees %= 360;
>> +	}
>> +
>> +	return degrees;
>> +}
>> +
>> +static void meson_clk_apply_phase_delay(struct clk_regmap *clk,
>> +					unsigned int phase,
>> +					unsigned int delay)
>> +{
>> +	struct meson_clk_phase_delay_data *ph = clk->data;
>> +	u32 val;
>> +
>> +	regmap_read(clk->map, SD_EMMC_CLOCK, &val);
>> +
>> +	val &= ~ph->phase_mask;
>> +	val |= phase << __ffs(ph->phase_mask);
>> +
>> +	if (ph->delay_mask) {
> 
> This imply that delay is delay is optional. In such case, it would be a regular
> "phase" and we already have a  driver for this. Please remove all the related
> code and make this parameter required for this clock type.
> 
OK. I will use APIs from clk-phase.c for ‘core' phase. 
> In the future, maybe we'll merge the 2 drivers.
> 
>> +		val &= ~ph->delay_mask;
>> +		val |= delay << __ffs(ph->delay_mask);
>> +	}
>> +
>> +	regmap_write(clk->map, SD_EMMC_CLOCK, val);
>> +}
>> +
>> +static int meson_clk_phase_delay_set_phase(struct clk_hw *hw, int degrees)
>> +{
>> +	struct clk_regmap *clk = to_clk_regmap(hw);
>> +	struct meson_clk_phase_delay_data *ph =
>> +		meson_clk_get_phase_delay_data(clk);
>> +	unsigned int phase_num = 1 <<  hweight_long(ph->phase_mask);
>> +	unsigned long period_ps, d = 0, r;
>> +	u64 p;
>> +
>> +	p = degrees % 360;
>> +
>> +	if (!ph->delay_mask) {
>> +		p = DIV_ROUND_CLOSEST_ULL(p, 360 / phase_num);
>> +	} else {
>> +		period_ps = DIV_ROUND_UP((unsigned long)NSEC_PER_SEC * 1000,
>> +					 clk_hw_get_rate(hw));
>> +
>> +		/* First compute the phase index (p), the remainder (r) is the
>> +		 * part we'll try to acheive using the delays (d).
>> +		 */
>> +		r = do_div(p, 360 / phase_num);
>> +		d = DIV_ROUND_CLOSEST(r * period_ps,
>> +				      360 * ph->delay_step_ps);
>> +		d = min(d, ph->delay_mask >> __ffs(ph->delay_mask));
>> +	}
>> +
>> +	meson_clk_apply_phase_delay(clk, p, d);
>> +	return 0;
>> +}
>> +
>> +const struct clk_ops meson_clk_phase_delay_ops = {
>> +	.get_phase = meson_clk_phase_delay_get_phase,
>> +	.set_phase = meson_clk_phase_delay_set_phase,
>> +};
>> +EXPORT_SYMBOL_GPL(meson_clk_phase_delay_ops);
>> diff --git a/drivers/clk/meson/clkc.h b/drivers/clk/meson/clkc.h
>> index 24cec16b6038..499834dd34f2 100644
>> --- a/drivers/clk/meson/clkc.h
>> +++ b/drivers/clk/meson/clkc.h
>> @@ -113,6 +113,18 @@ struct clk_regmap _name = {						\
>>  	},								\
>>  };
>>  
>> +struct meson_clk_phase_delay_data {
>> +	unsigned long			phase_mask;
>> +	unsigned long			delay_mask;
> 
> Like every other clock drivers in the amlogic directory, please use struct parm
> to decribe the fields.
> 
OK. I will use struct parm to describe phase and delay register fields.
>> +	unsigned int			delay_step_ps;
>> +};
>> +
>> +static inline struct meson_clk_phase_delay_data *
>> +meson_clk_get_phase_delay_data(struct clk_regmap *clk)
>> +{
>> +	return (struct meson_clk_phase_delay_data *)clk->data;
>> +}
>> +
>>  /* clk_ops */
>>  extern const struct clk_ops meson_clk_pll_ro_ops;
>>  extern const struct clk_ops meson_clk_pll_ops;
>> @@ -120,5 +132,6 @@ extern const struct clk_ops meson_clk_cpu_ops;
>>  extern const struct clk_ops meson_clk_mpll_ro_ops;
>>  extern const struct clk_ops meson_clk_mpll_ops;
>>  extern const struct clk_ops meson_clk_phase_ops;
>> +extern const struct clk_ops meson_clk_phase_delay_ops;
>>  
>>  #endif /* __CLKC_H */
> 
> 
> .
> 

Re: [PATCH v4 3/3] clk: meson: add sub MMC clock controller driver

[Jianxin Pan]

On 2018/8/10 20:47, Jerome Brunet wrote:
> On Thu, 2018-08-09 at 15:07 +0800, Yixun Lan wrote:
>> The patch will add a MMC clock controller driver which used by MMC or NAND,
>> It provide a mux and divider clock, and three phase clocks - core, tx, tx.
>>
>> Two clocks are provided as the parent of MMC clock controller from
>> upper layer clock controller - eg "amlogic,axg-clkc" in AXG platform.
>>
>> To specify which clock the MMC or NAND driver may consume,
>> the preprocessor macros in the dt-bindings/clock/amlogic,mmc-clkc.h header
>> can be used in the device tree sources.
>>
>> Signed-off-by: Yixun Lan <yixun.lan@amlogic.com>
>> ---
>>  drivers/clk/meson/Kconfig    |  10 ++
>>  drivers/clk/meson/Makefile   |   1 +
>>  drivers/clk/meson/mmc-clkc.c | 275 +++++++++++++++++++++++++++++++++++
>>  3 files changed, 286 insertions(+)
>>  create mode 100644 drivers/clk/meson/mmc-clkc.c
>>
>> diff --git a/drivers/clk/meson/Kconfig b/drivers/clk/meson/Kconfig
>> index efaa70f682b4..8b8ccbcfed1d 100644
>> --- a/drivers/clk/meson/Kconfig
>> +++ b/drivers/clk/meson/Kconfig
>> @@ -15,6 +15,16 @@ config COMMON_CLK_MESON_AO
>>  	select COMMON_CLK_REGMAP_MESON
>>  	select RESET_CONTROLLER
>>  
>> +config COMMON_CLK_MMC_MESON
>> +	tristate "Meson MMC Sub Clock Controller Driver"
>> +	depends on COMMON_CLK_AMLOGIC
>> +	select MFD_SYSCON
>> +	select REGMAP
>> +	help
>> +	  Support for the MMC sub clock controller on Amlogic Meson Platform,
>> +	  which include S905 (GXBB, GXL), A113D/X (AXG) devices.
>> +	  Say Y if you want this clock enabled.
>> +
>>  config COMMON_CLK_REGMAP_MESON
>>  	bool
>>  	select REGMAP
>> diff --git a/drivers/clk/meson/Makefile b/drivers/clk/meson/Makefile
>> index 39ce5661b654..31c16d524a4b 100644
>> --- a/drivers/clk/meson/Makefile
>> +++ b/drivers/clk/meson/Makefile
>> @@ -9,4 +9,5 @@ obj-$(CONFIG_COMMON_CLK_MESON8B) += meson8b.o
>>  obj-$(CONFIG_COMMON_CLK_GXBB)	 += gxbb.o gxbb-aoclk.o gxbb-aoclk-32k.o
>>  obj-$(CONFIG_COMMON_CLK_AXG)	 += axg.o axg-aoclk.o
>>  obj-$(CONFIG_COMMON_CLK_AXG_AUDIO)	+= axg-audio.o
>> +obj-$(CONFIG_COMMON_CLK_MMC_MESON) 	+= mmc-clkc.o
>>  obj-$(CONFIG_COMMON_CLK_REGMAP_MESON)	+= clk-regmap.o
>> diff --git a/drivers/clk/meson/mmc-clkc.c b/drivers/clk/meson/mmc-clkc.c
>> new file mode 100644
>> index 000000000000..6aa055f7e62c
>> --- /dev/null
>> +++ b/drivers/clk/meson/mmc-clkc.c
>> @@ -0,0 +1,275 @@
>> +// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
>> +/*
>> + * Amlogic Meson MMC Sub Clock Controller Driver
>> + *
>> + * Copyright (c) 2017 Baylibre SAS.
>> + * Author: Jerome Brunet <jbrunet@baylibre.com>
>> + *
>> + * Copyright (c) 2018 Amlogic, inc.
>> + * Author: Yixun Lan <yixun.lan@amlogic.com>
>> + */
>> +
>> +#include <linux/clk.h>
>> +#include <linux/module.h>
>> +#include <linux/regmap.h>
>> +#include <linux/slab.h>
>> +#include <linux/of_device.h>
>> +#include <linux/mfd/syscon.h>
>> +#include <linux/platform_device.h>
>> +#include <dt-bindings/clock/amlogic,mmc-clkc.h>
>> +
>> +#include "clkc.h"
>> +
>> +/* clock ID used by internal driver */
>> +#define CLKID_MMC_MUX			0
>> +
>> +#define SD_EMMC_CLOCK			0
>> +#define   CLK_DIV_MASK			GENMASK(5, 0)
>> +#define   CLK_SRC_MASK			GENMASK(7, 6)
>> +#define   CLK_CORE_PHASE_MASK		GENMASK(9, 8)
>> +#define   CLK_TX_PHASE_MASK		GENMASK(11, 10)
>> +#define   CLK_RX_PHASE_MASK		GENMASK(13, 12)
>> +#define   CLK_V2_TX_DELAY_MASK		GENMASK(19, 16)
>> +#define   CLK_V2_RX_DELAY_MASK		GENMASK(23, 20)
>> +#define   CLK_V2_ALWAYS_ON		BIT(24)
>> +
>> +#define   CLK_V3_TX_DELAY_MASK		GENMASK(21, 16)
>> +#define   CLK_V3_RX_DELAY_MASK		GENMASK(27, 22)
>> +#define   CLK_V3_ALWAYS_ON		BIT(28)
>> +
>> +#define   CLK_DELAY_STEP_PS		200
>> +#define   CLK_PHASE_STEP		30
>> +#define   CLK_PHASE_POINT_NUM		(360 / CLK_PHASE_STEP)
>> +
>> +#define MUX_CLK_NUM_PARENTS		2
>> +#define MMC_MAX_CLKS			5
>> +
>> +struct mmc_clkc_data {
>> +	struct meson_clk_phase_delay_data	tx;
>> +	struct meson_clk_phase_delay_data	rx;
>> +};
>> +
>> +static struct clk_regmap_mux_data mmc_clkc_mux_data = {
>> +	.offset		= SD_EMMC_CLOCK,
>> +	.mask		= 0x3,
>> +	.shift		= 6,
>> +	.flags		= CLK_DIVIDER_ROUND_CLOSEST,
>> +};
>> +
>> +static struct clk_regmap_div_data mmc_clkc_div_data = {
>> +	.offset		= SD_EMMC_CLOCK,
>> +	.shift		= 0,
>> +	.width		= 6,
>> +	.flags		= CLK_DIVIDER_ROUND_CLOSEST | CLK_DIVIDER_ONE_BASED,
>> +};
>> +
>> +static struct meson_clk_phase_delay_data mmc_clkc_core_phase_delay = {
>> +	.phase_mask	= CLK_CORE_PHASE_MASK,
>> +};
>> +
>> +static const struct mmc_clkc_data mmc_clkc_gx_data = {
>> +	{
>> +		.phase_mask	= CLK_TX_PHASE_MASK,
>> +		.delay_mask	= CLK_V2_TX_DELAY_MASK,
>> +		.delay_step_ps	= CLK_DELAY_STEP_PS,
>> +	},
>> +	{
>> +		.phase_mask	= CLK_RX_PHASE_MASK,
>> +		.delay_mask	= CLK_V2_RX_DELAY_MASK,
>> +		.delay_step_ps	= CLK_DELAY_STEP_PS,
>> +	},
>> +};
>> +
>> +static const struct mmc_clkc_data mmc_clkc_axg_data = {
>> +	{
>> +		.phase_mask	= CLK_TX_PHASE_MASK,
>> +		.delay_mask	= CLK_V3_TX_DELAY_MASK,
>> +		.delay_step_ps	= CLK_DELAY_STEP_PS,
>> +	},
>> +	{
>> +		.phase_mask	= CLK_RX_PHASE_MASK,
>> +		.delay_mask	= CLK_V3_RX_DELAY_MASK,
>> +		.delay_step_ps	= CLK_DELAY_STEP_PS,
>> +	},
>> +};
>> +
>> +static const struct of_device_id mmc_clkc_match_table[] = {
>> +	{
>> +		.compatible	= "amlogic,gx-mmc-clkc",
>> +		.data		= &mmc_clkc_gx_data
>> +	},
>> +	{
>> +		.compatible	= "amlogic,axg-mmc-clkc",
>> +		.data		= &mmc_clkc_axg_data
>> +	},
>> +	{}
>> +};
>> +MODULE_DEVICE_TABLE(of, mmc_clkc_match_table);
>> +
>> +static struct clk_regmap *
>> +mmc_clkc_register_clk(struct device *dev, struct regmap *map,
>> +		      struct clk_init_data *init,
>> +		      const char *suffix, void *data)
>> +{
>> +	struct clk_regmap *clk;
>> +	char *name;
>> +	int ret;
>> +
>> +	clk = devm_kzalloc(dev, sizeof(*clk), GFP_KERNEL);
>> +	if (!clk)
>> +		return ERR_PTR(-ENOMEM);
>> +
>> +	name = kasprintf(GFP_KERNEL, "%s#%s", dev_name(dev), suffix);
>> +	if (!name)
>> +		return ERR_PTR(-ENOMEM);
>> +
>> +	init->name = name;
>> +
>> +	clk->map = map;
>> +	clk->data = data;
>> +	clk->hw.init = init;
>> +
>> +	ret = devm_clk_hw_register(dev, &clk->hw);
>> +	if (ret)
>> +		clk = ERR_PTR(ret);
>> +
>> +	kfree(name);
>> +	return clk;
>> +}
>> +
>> +static struct clk_regmap *mmc_clkc_register_mux(struct device *dev,
>> +						struct regmap *map)
>> +{
>> +	const char *parent_names[MUX_CLK_NUM_PARENTS];
>> +	struct clk_init_data init;
>> +	struct clk_regmap *mux;
>> +	struct clk *clk;
>> +	int i;
>> +
>> +	for (i = 0; i < MUX_CLK_NUM_PARENTS; i++) {
>> +		char name[8];
>> +
>> +		snprintf(name, sizeof(name), "clkin%d", i);
>> +		clk = devm_clk_get(dev, name);
>> +		if (IS_ERR(clk)) {
>> +			if (clk != ERR_PTR(-EPROBE_DEFER))
>> +				dev_err(dev, "Missing clock %s\n", name);
>> +			return ERR_PTR((long)clk);
>> +		}
>> +
>> +		parent_names[i] = __clk_get_name(clk);
>> +	}
>> +
>> +	init.ops = &clk_regmap_mux_ops;
>> +	init.flags = CLK_SET_RATE_PARENT;
>> +	init.parent_names = parent_names;
>> +	init.num_parents = MUX_CLK_NUM_PARENTS;
>> +
>> +	mux = mmc_clkc_register_clk(dev, map, &init, "mux", &mmc_clkc_mux_data);
>> +	if (IS_ERR(mux))
>> +		dev_err(dev, "Mux clock registration failed\n");
>> +
>> +	return mux;
>> +}
>> +
>> +static struct clk_regmap *
>> +mmc_clkc_register_other_clk(struct device *dev, struct regmap *map,
> 
> This is a poor name. It does not help understand what the function does.
> mmc_clkc_register_clk_with_parent or whatever helps understand what's going on
> 
OK, I will repleace it with mmc_clkc_register_clk_with_parent(). Thanks for your review.
>> +			    char *suffix, char *parent_suffix,
> 
> You should not have to rebuild the parent name once again.
> Pass the clk_hw* of the parent and get the name from it.
> 
yes, mmc_clkc_register_clk_with_parent() can use parent's hw.init->name directly.
>> +			    unsigned long flags,
>> +			    const struct clk_ops *ops, void *data)
>> +{
>> +	struct clk_init_data init;
>> +	struct clk_regmap *clk;
>> +	char *parent;
>> +
>> +	parent = kasprintf(GFP_KERNEL, "%s#%s", dev_name(dev), parent_suffix);
>> +	if (!parent)
>> +		return ERR_PTR(-ENOMEM);
>> +
>> +	init.ops = ops;
>> +	init.flags = flags;
>> +	init.parent_names = (const char* const []){ parent, };
>> +	init.num_parents = 1;
>> +
>> +	clk = mmc_clkc_register_clk(dev, map, &init, suffix, data);
>> +	if (IS_ERR(clk))
>> +		dev_err(dev, "Core %s clock registration failed\n", suffix);
>> +
>> +	kfree(parent);
>> +	return clk;
>> +}
>> +
>> +static int mmc_clkc_probe(struct platform_device *pdev)
>> +{
>> +	struct clk_hw_onecell_data *onecell_data;
>> +	struct device *dev = &pdev->dev;
>> +	struct mmc_clkc_data *data;
>> +	struct regmap *map;
>> +	struct clk_regmap *mux, *div, *core, *rx, *tx;
> 
> Do you really need all this ? or could store them in your onecell_data->hws
> table as you go ?
> 
3 of them can be removed. Then one local variable will be shared several times. 
>> +
>> +	data = (struct mmc_clkc_data *)of_device_get_match_data(dev);
>> +	if (!data)
>> +		return -ENODEV;
>> +
>> +	map = syscon_node_to_regmap(dev->of_node);
>> +	if (IS_ERR(map)) {
>> +		dev_err(dev, "could not find mmc clock controller\n");
>> +		return PTR_ERR(map);
>> +	}
>> +
>> +	onecell_data = devm_kzalloc(dev, sizeof(*onecell_data) +
>> +				    sizeof(*onecell_data->hws) * MMC_MAX_CLKS,
>> +				    GFP_KERNEL);
>> +	if (!onecell_data)
>> +		return -ENOMEM;
>> +
>> +	mux = mmc_clkc_register_mux(dev, map);
>> +	if (IS_ERR(mux))
>> +		return PTR_ERR(mux);
>> +
>> +	div = mmc_clkc_register_other_clk(dev, map, "div", "mux",
>> +					  CLK_SET_RATE_PARENT,
>> +					  &clk_regmap_divider_ops,
>> +					  &mmc_clkc_div_data);
>> +	if (IS_ERR(div))
>> +		return PTR_ERR(div);
>> +
>> +	core = mmc_clkc_register_other_clk(dev, map, "core", "div",
>> +					   CLK_SET_RATE_PARENT,
>> +					   &meson_clk_phase_delay_ops,
>> +					   &mmc_clkc_core_phase_delay);
>> +	if (IS_ERR(core))
>> +		return PTR_ERR(core);
>> +
>> +	rx = mmc_clkc_register_other_clk(dev, map, "rx", "core", 0,
>> +					 &meson_clk_phase_delay_ops,
>> +					 &data->rx);
>> +	if (IS_ERR(rx))
>> +		return PTR_ERR(rx);
>> +
>> +	tx = mmc_clkc_register_other_clk(dev, map, "tx", "core", 0,
>> +					 &meson_clk_phase_delay_ops,
>> +					 &data->tx);
>> +	if (IS_ERR(tx))
>> +		return PTR_ERR(tx);
>> +
>> +	onecell_data->hws[CLKID_MMC_MUX]		= &mux->hw,
>> +	onecell_data->hws[CLKID_MMC_DIV]		= &div->hw,
>> +	onecell_data->hws[CLKID_MMC_PHASE_CORE]		= &core->hw,
>> +	onecell_data->hws[CLKID_MMC_PHASE_RX]		= &rx->hw,
>> +	onecell_data->hws[CLKID_MMC_PHASE_TX]		= &tx->hw,
>> +	onecell_data->num				= MMC_MAX_CLKS;
>> +
>> +	return devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get,
>> +					   onecell_data);
>> +}
>> +
>> +static struct platform_driver mmc_clkc_driver = {
>> +	.probe		= mmc_clkc_probe,
>> +	.driver		= {
>> +		.name	= "meson-mmc-clkc",
>> +		.of_match_table = of_match_ptr(mmc_clkc_match_table),
>> +	},
>> +};
>> +
>> +module_platform_driver(mmc_clkc_driver);
> 
> 
> .
>