[PATCH 0/9] sun6i / A31 ir receiver support

[PATCH 0/9] sun6i / A31 ir receiver support

[Hans de Goede]

Hi Maxime, et al,

Here is a patch series adding support for the ir receiver found on sun6i,
it is the same one as found on sun5i (which is very similar to the sun4i
one we already support), except that as usual on sun6i it needs a reset
to be de-asserted.

More interesting is the clocking of it, it is clocked through a clock which
comes from the prcm module, I guess this is done so that the remote can keep
working with all the main clocks turned off. So this patch series starts
with adding support for this new ir clock.

I've discussed how to best upstream this with Mauro Chehab, the media
maintainer, and since this only touches sunxi-cir.c under the media tree, he
is fine with everything going upstream to your tree.

Regards,

Hans

[PATCH 1/9] clk: sunxi: Give sunxi_factors_register a registers parameter

[Hans de Goede]

Before this commit sunxi_factors_register uses of_iomap(node, 0) to get
the clk registers. The sun6i prcm has factor clocks, for which we want to
use sunxi_factors_register, but of_iomap(node, 0) does not work for the prcm
factor clocks, because the prcm uses the mfd framework, so the registers
are not part of the dt-node, instead they are added to the platform_device,
as platform_device resources.

This commit makes getting the registers the callers duty, so that
sunxi_factors_register can be used with mfd instantiated platform device too.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/clk/sunxi/clk-factors.c    | 10 ++++------
 drivers/clk/sunxi/clk-factors.h    |  7 ++++---
 drivers/clk/sunxi/clk-mod0.c       |  6 ++++--
 drivers/clk/sunxi/clk-sun8i-mbus.c |  2 +-
 drivers/clk/sunxi/clk-sunxi.c      |  3 ++-
 5 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/drivers/clk/sunxi/clk-factors.c b/drivers/clk/sunxi/clk-factors.c
index f83ba09..fc4f4b5 100644
--- a/drivers/clk/sunxi/clk-factors.c
+++ b/drivers/clk/sunxi/clk-factors.c
@@ -156,9 +156,10 @@ static const struct clk_ops clk_factors_ops = {
 	.set_rate = clk_factors_set_rate,
 };
 
-struct clk * __init sunxi_factors_register(struct device_node *node,
-					   const struct factors_data *data,
-					   spinlock_t *lock)
+struct clk *sunxi_factors_register(struct device_node *node,
+				   const struct factors_data *data,
+				   spinlock_t *lock,
+				   void __iomem *reg)
 {
 	struct clk *clk;
 	struct clk_factors *factors;
@@ -168,11 +169,8 @@ struct clk * __init sunxi_factors_register(struct device_node *node,
 	struct clk_hw *mux_hw = NULL;
 	const char *clk_name = node->name;
 	const char *parents[FACTORS_MAX_PARENTS];
-	void __iomem *reg;
 	int i = 0;
 
-	reg = of_iomap(node, 0);
-
 	/* if we have a mux, we will have >1 parents */
 	while (i < FACTORS_MAX_PARENTS &&
 	       (parents[i] = of_clk_get_parent_name(node, i)) != NULL)
diff --git a/drivers/clk/sunxi/clk-factors.h b/drivers/clk/sunxi/clk-factors.h
index 9913840..1f5526d 100644
--- a/drivers/clk/sunxi/clk-factors.h
+++ b/drivers/clk/sunxi/clk-factors.h
@@ -37,8 +37,9 @@ struct clk_factors {
 	spinlock_t *lock;
 };
 
-struct clk * __init sunxi_factors_register(struct device_node *node,
-					   const struct factors_data *data,
-					   spinlock_t *lock);
+struct clk *sunxi_factors_register(struct device_node *node,
+				   const struct factors_data *data,
+				   spinlock_t *lock,
+				   void __iomem *reg);
 
 #endif
diff --git a/drivers/clk/sunxi/clk-mod0.c b/drivers/clk/sunxi/clk-mod0.c
index 4a56385..9530833 100644
--- a/drivers/clk/sunxi/clk-mod0.c
+++ b/drivers/clk/sunxi/clk-mod0.c
@@ -78,7 +78,8 @@ static DEFINE_SPINLOCK(sun4i_a10_mod0_lock);
 
 static void __init sun4i_a10_mod0_setup(struct device_node *node)
 {
-	sunxi_factors_register(node, &sun4i_a10_mod0_data, &sun4i_a10_mod0_lock);
+	sunxi_factors_register(node, &sun4i_a10_mod0_data,
+			       &sun4i_a10_mod0_lock, of_iomap(node, 0));
 }
 CLK_OF_DECLARE(sun4i_a10_mod0, "allwinner,sun4i-a10-mod0-clk", sun4i_a10_mod0_setup);
 
@@ -86,7 +87,8 @@ static DEFINE_SPINLOCK(sun5i_a13_mbus_lock);
 
 static void __init sun5i_a13_mbus_setup(struct device_node *node)
 {
-	struct clk *mbus = sunxi_factors_register(node, &sun4i_a10_mod0_data, &sun5i_a13_mbus_lock);
+	struct clk *mbus = sunxi_factors_register(node, &sun4i_a10_mod0_data,
+				      &sun5i_a13_mbus_lock, of_iomap(node, 0));
 
 	/* The MBUS clocks needs to be always enabled */
 	__clk_get(mbus);
diff --git a/drivers/clk/sunxi/clk-sun8i-mbus.c b/drivers/clk/sunxi/clk-sun8i-mbus.c
index 8e49b44..444d603 100644
--- a/drivers/clk/sunxi/clk-sun8i-mbus.c
+++ b/drivers/clk/sunxi/clk-sun8i-mbus.c
@@ -69,7 +69,7 @@ static DEFINE_SPINLOCK(sun8i_a23_mbus_lock);
 static void __init sun8i_a23_mbus_setup(struct device_node *node)
 {
 	struct clk *mbus = sunxi_factors_register(node, &sun8i_a23_mbus_data,
-						  &sun8i_a23_mbus_lock);
+				&sun8i_a23_mbus_lock, of_iomap(node, 0));
 
 	/* The MBUS clocks needs to be always enabled */
 	__clk_get(mbus);
diff --git a/drivers/clk/sunxi/clk-sunxi.c b/drivers/clk/sunxi/clk-sunxi.c
index d5dc951..f19e0f9 100644
--- a/drivers/clk/sunxi/clk-sunxi.c
+++ b/drivers/clk/sunxi/clk-sunxi.c
@@ -521,7 +521,8 @@ static const struct factors_data sun7i_a20_out_data __initconst = {
 static struct clk * __init sunxi_factors_clk_setup(struct device_node *node,
 						   const struct factors_data *data)
 {
-	return sunxi_factors_register(node, data, &clk_lock);
+	return sunxi_factors_register(node, data, &clk_lock,
+				      of_iomap(node, 0));
 }
 
 
-- 
2.1.0

[PATCH 2/9] clk: sunxi: Make sun4i_a10_mod0_data available outside of clk-mod0.c

[Hans de Goede]

The sun6i prcm has mod0 compatible clocks, these need a separate driver
because the prcm uses the mfd framework, but we do want to re-use the
standard mod0 clk handling from clk-mod0.c for this, export
sun4i_a10_mod0_data, so that the prcm mod0 clk driver can use this.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/clk/sunxi/clk-mod0.c | 2 +-
 drivers/clk/sunxi/clk-mod0.h | 8 ++++++++
 2 files changed, 9 insertions(+), 1 deletion(-)
 create mode 100644 drivers/clk/sunxi/clk-mod0.h

diff --git a/drivers/clk/sunxi/clk-mod0.c b/drivers/clk/sunxi/clk-mod0.c
index 9530833..0989502 100644
--- a/drivers/clk/sunxi/clk-mod0.c
+++ b/drivers/clk/sunxi/clk-mod0.c
@@ -67,7 +67,7 @@ static struct clk_factors_config sun4i_a10_mod0_config = {
 	.pwidth = 2,
 };
 
-static const struct factors_data sun4i_a10_mod0_data __initconst = {
+const struct factors_data sun4i_a10_mod0_data = {
 	.enable = 31,
 	.mux = 24,
 	.table = &sun4i_a10_mod0_config,
diff --git a/drivers/clk/sunxi/clk-mod0.h b/drivers/clk/sunxi/clk-mod0.h
new file mode 100644
index 0000000..49aa9ab
--- /dev/null
+++ b/drivers/clk/sunxi/clk-mod0.h
@@ -0,0 +1,8 @@
+#ifndef __MACH_SUNXI_CLK_MOD0_H
+#define __MACH_SUNXI_CLK_MOD0_H
+
+#include "clk-factors.h"
+
+extern const struct factors_data sun4i_a10_mod0_data;
+
+#endif
-- 
2.1.0

[PATCH 3/9] clk: sunxi: Add prcm mod0 clock driver

[Hans de Goede]

Add a driver for mod0 clocks found in the prcm. Currently there is only
one mod0 clocks in the prcm, the ir clock.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 Documentation/devicetree/bindings/clock/sunxi.txt |  1 +
 drivers/clk/sunxi/Makefile                        |  2 +-
 drivers/clk/sunxi/clk-sun6i-prcm-mod0.c           | 63 +++++++++++++++++++++++
 drivers/mfd/sun6i-prcm.c                          | 14 +++++
 4 files changed, 79 insertions(+), 1 deletion(-)
 create mode 100644 drivers/clk/sunxi/clk-sun6i-prcm-mod0.c

diff --git a/Documentation/devicetree/bindings/clock/sunxi.txt b/Documentation/devicetree/bindings/clock/sunxi.txt
index ed116df..342c75a 100644
--- a/Documentation/devicetree/bindings/clock/sunxi.txt
+++ b/Documentation/devicetree/bindings/clock/sunxi.txt
@@ -56,6 +56,7 @@ Required properties:
 	"allwinner,sun4i-a10-usb-clk" - for usb gates + resets on A10 / A20
 	"allwinner,sun5i-a13-usb-clk" - for usb gates + resets on A13
 	"allwinner,sun6i-a31-usb-clk" - for usb gates + resets on A31
+	"allwinner,sun6i-a31-ir-clk" - for the ir clock on A31
 
 Required properties for all clocks:
 - reg : shall be the control register address for the clock.
diff --git a/drivers/clk/sunxi/Makefile b/drivers/clk/sunxi/Makefile
index 7ddc2b5..daf8b1c 100644
--- a/drivers/clk/sunxi/Makefile
+++ b/drivers/clk/sunxi/Makefile
@@ -10,4 +10,4 @@ obj-y += clk-sun8i-mbus.o
 
 obj-$(CONFIG_MFD_SUN6I_PRCM) += \
 	clk-sun6i-ar100.o clk-sun6i-apb0.o clk-sun6i-apb0-gates.o \
-	clk-sun8i-apb0.o
+	clk-sun8i-apb0.o clk-sun6i-prcm-mod0.o
diff --git a/drivers/clk/sunxi/clk-sun6i-prcm-mod0.c b/drivers/clk/sunxi/clk-sun6i-prcm-mod0.c
new file mode 100644
index 0000000..e80f18e
--- /dev/null
+++ b/drivers/clk/sunxi/clk-sun6i-prcm-mod0.c
@@ -0,0 +1,63 @@
+/*
+ * Allwinner A31 PRCM mod0 clock driver
+ *
+ * Copyright (C) 2014 Hans de Goede <hdegoede@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/clkdev.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+
+#include "clk-factors.h"
+#include "clk-mod0.h"
+
+static const struct of_device_id sun6i_a31_prcm_mod0_clk_dt_ids[] = {
+	{ .compatible = "allwinner,sun6i-a31-ir-clk" },
+	{ /* sentinel */ }
+};
+
+static DEFINE_SPINLOCK(sun6i_prcm_mod0_lock);
+
+static int sun6i_a31_prcm_mod0_clk_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct resource *r;
+	void __iomem *reg;
+
+	if (!np)
+		return -ENODEV;
+
+	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	reg = devm_ioremap_resource(&pdev->dev, r);
+	if (IS_ERR(reg))
+		return PTR_ERR(reg);
+
+	sunxi_factors_register(np, &sun4i_a10_mod0_data,
+			       &sun6i_prcm_mod0_lock, reg);
+	return 0;
+}
+
+static struct platform_driver sun6i_a31_prcm_mod0_clk_driver = {
+	.driver = {
+		.name = "sun6i-a31-prcm-mod0-clk",
+		.of_match_table = sun6i_a31_prcm_mod0_clk_dt_ids,
+	},
+	.probe = sun6i_a31_prcm_mod0_clk_probe,
+};
+module_platform_driver(sun6i_a31_prcm_mod0_clk_driver);
+
+MODULE_DESCRIPTION("Allwinner A31 PRCM mod0 clock driver");
+MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
+MODULE_LICENSE("GPL");
diff --git a/drivers/mfd/sun6i-prcm.c b/drivers/mfd/sun6i-prcm.c
index 283ab8d..ff1254f 100644
--- a/drivers/mfd/sun6i-prcm.c
+++ b/drivers/mfd/sun6i-prcm.c
@@ -41,6 +41,14 @@ static const struct resource sun6i_a31_apb0_gates_clk_res[] = {
 	},
 };
 
+static const struct resource sun6i_a31_ir_clk_res[] = {
+	{
+		.start = 0x54,
+		.end = 0x57,
+		.flags = IORESOURCE_MEM,
+	},
+};
+
 static const struct resource sun6i_a31_apb0_rstc_res[] = {
 	{
 		.start = 0xb0,
@@ -69,6 +77,12 @@ static const struct mfd_cell sun6i_a31_prcm_subdevs[] = {
 		.resources = sun6i_a31_apb0_gates_clk_res,
 	},
 	{
+		.name = "sun6i-a31-ir-clk",
+		.of_compatible = "allwinner,sun6i-a31-ir-clk",
+		.num_resources = ARRAY_SIZE(sun6i_a31_ir_clk_res),
+		.resources = sun6i_a31_ir_clk_res,
+	},
+	{
 		.name = "sun6i-a31-apb0-clock-reset",
 		.of_compatible = "allwinner,sun6i-a31-clock-reset",
 		.num_resources = ARRAY_SIZE(sun6i_a31_apb0_rstc_res),
-- 
2.1.0

[PATCH 4/9] rc: sunxi-cir: Add support for an optional reset controller

[Hans de Goede]

On sun6i the cir block is attached to the reset controller, add support
for de-asserting the reset if a reset controller is specified in dt.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/media/rc/sunxi-cir.c | 25 +++++++++++++++++++++++--
 1 file changed, 23 insertions(+), 2 deletions(-)

diff --git a/drivers/media/rc/sunxi-cir.c b/drivers/media/rc/sunxi-cir.c
index bcee8e1..895fb65 100644
--- a/drivers/media/rc/sunxi-cir.c
+++ b/drivers/media/rc/sunxi-cir.c
@@ -23,6 +23,7 @@
 #include <linux/interrupt.h>
 #include <linux/module.h>
 #include <linux/of_platform.h>
+#include <linux/reset.h>
 #include <media/rc-core.h>
 
 #define SUNXI_IR_DEV "sunxi-ir"
@@ -95,6 +96,7 @@ struct sunxi_ir {
 	int             irq;
 	struct clk      *clk;
 	struct clk      *apb_clk;
+	struct reset_control *rst;
 	const char      *map_name;
 };
 
@@ -166,15 +168,29 @@ static int sunxi_ir_probe(struct platform_device *pdev)
 		return PTR_ERR(ir->clk);
 	}
 
+	/* Reset (optional) */
+	ir->rst = devm_reset_control_get_optional(dev, NULL);
+	if (IS_ERR(ir->rst)) {
+		ret = PTR_ERR(ir->rst);
+		if (ret == -EPROBE_DEFER)
+			return ret;
+		ir->rst = NULL;
+	} else {
+		ret = reset_control_deassert(ir->rst);
+		if (ret)
+			return ret;
+	}
+
 	ret = clk_set_rate(ir->clk, SUNXI_IR_BASE_CLK);
 	if (ret) {
 		dev_err(dev, "set ir base clock failed!\n");
-		return ret;
+		goto exit_reset_assert;
 	}
 
 	if (clk_prepare_enable(ir->apb_clk)) {
 		dev_err(dev, "try to enable apb_ir_clk failed\n");
-		return -EINVAL;
+		ret = -EINVAL;
+		goto exit_reset_assert;
 	}
 
 	if (clk_prepare_enable(ir->clk)) {
@@ -271,6 +287,9 @@ exit_clkdisable_clk:
 	clk_disable_unprepare(ir->clk);
 exit_clkdisable_apb_clk:
 	clk_disable_unprepare(ir->apb_clk);
+exit_reset_assert:
+	if (ir->rst)
+		reset_control_assert(ir->rst);
 
 	return ret;
 }
@@ -282,6 +301,8 @@ static int sunxi_ir_remove(struct platform_device *pdev)
 
 	clk_disable_unprepare(ir->clk);
 	clk_disable_unprepare(ir->apb_clk);
+	if (ir->rst)
+		reset_control_assert(ir->rst);
 
 	spin_lock_irqsave(&ir->ir_lock, flags);
 	/* disable IR IRQ */
-- 
2.1.0

[PATCH 5/9] rc: sunxi-cir: Add support for the larger fifo found on sun5i and sun6i

[Hans de Goede]

Add support for the larger fifo found on sun5i and sun6i, having a separate
compatible for the ir found on sun5i & sun6i also is useful if we ever want
to add ir transmit support, because the sun5i & sun6i version do not have
transmit support.

Note this commits also adds checking for the end-of-packet interrupt flag
(which was already enabled), as the fifo-data-available interrupt flag only
gets set when the trigger-level is exceeded. So far we've been getting away
with not doing this because of the low trigger-level, but this is something
which we should have done since day one.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 .../devicetree/bindings/media/sunxi-ir.txt          |  2 +-
 drivers/media/rc/sunxi-cir.c                        | 21 ++++++++++++---------
 2 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/Documentation/devicetree/bindings/media/sunxi-ir.txt b/Documentation/devicetree/bindings/media/sunxi-ir.txt
index 23dd5ad..5767128 100644
--- a/Documentation/devicetree/bindings/media/sunxi-ir.txt
+++ b/Documentation/devicetree/bindings/media/sunxi-ir.txt
@@ -1,7 +1,7 @@
 Device-Tree bindings for SUNXI IR controller found in sunXi SoC family
 
 Required properties:
-- compatible	    : should be "allwinner,sun4i-a10-ir";
+- compatible	    : "allwinner,sun4i-a10-ir" or "allwinner,sun5i-a13-ir"
 - clocks	    : list of clock specifiers, corresponding to
 		      entries in clock-names property;
 - clock-names	    : should contain "apb" and "ir" entries;
diff --git a/drivers/media/rc/sunxi-cir.c b/drivers/media/rc/sunxi-cir.c
index 895fb65..559b0e3 100644
--- a/drivers/media/rc/sunxi-cir.c
+++ b/drivers/media/rc/sunxi-cir.c
@@ -56,12 +56,12 @@
 #define REG_RXINT_RAI_EN		BIT(4)
 
 /* Rx FIFO available byte level */
-#define REG_RXINT_RAL(val)    (((val) << 8) & (GENMASK(11, 8)))
+#define REG_RXINT_RAL(val)    ((val) << 8)
 
 /* Rx Interrupt Status */
 #define SUNXI_IR_RXSTA_REG    0x30
 /* RX FIFO Get Available Counter */
-#define REG_RXSTA_GET_AC(val) (((val) >> 8) & (GENMASK(5, 0)))
+#define REG_RXSTA_GET_AC(val) (((val) >> 8) & (ir->fifo_size * 2 - 1))
 /* Clear all interrupt status value */
 #define REG_RXSTA_CLEARALL    0xff
 
@@ -72,10 +72,6 @@
 /* CIR_REG register idle threshold */
 #define REG_CIR_ITHR(val)    (((val) << 8) & (GENMASK(15, 8)))
 
-/* Hardware supported fifo size */
-#define SUNXI_IR_FIFO_SIZE    16
-/* How many messages in FIFO trigger IRQ */
-#define TRIGGER_LEVEL         8
 /* Required frequency for IR0 or IR1 clock in CIR mode */
 #define SUNXI_IR_BASE_CLK     8000000
 /* Frequency after IR internal divider  */
@@ -94,6 +90,7 @@ struct sunxi_ir {
 	struct rc_dev   *rc;
 	void __iomem    *base;
 	int             irq;
+	int		fifo_size;
 	struct clk      *clk;
 	struct clk      *apb_clk;
 	struct reset_control *rst;
@@ -115,11 +112,11 @@ static irqreturn_t sunxi_ir_irq(int irqno, void *dev_id)
 	/* clean all pending statuses */
 	writel(status | REG_RXSTA_CLEARALL, ir->base + SUNXI_IR_RXSTA_REG);
 
-	if (status & REG_RXINT_RAI_EN) {
+	if (status & (REG_RXINT_RAI_EN | REG_RXINT_RPEI_EN)) {
 		/* How many messages in fifo */
 		rc  = REG_RXSTA_GET_AC(status);
 		/* Sanity check */
-		rc = rc > SUNXI_IR_FIFO_SIZE ? SUNXI_IR_FIFO_SIZE : rc;
+		rc = rc > ir->fifo_size ? ir->fifo_size : rc;
 		/* If we have data */
 		for (cnt = 0; cnt < rc; cnt++) {
 			/* for each bit in fifo */
@@ -156,6 +153,11 @@ static int sunxi_ir_probe(struct platform_device *pdev)
 	if (!ir)
 		return -ENOMEM;
 
+	if (of_device_is_compatible(dn, "allwinner,sun5i-a13-ir"))
+		ir->fifo_size = 64;
+	else
+		ir->fifo_size = 16;
+
 	/* Clock */
 	ir->apb_clk = devm_clk_get(dev, "apb");
 	if (IS_ERR(ir->apb_clk)) {
@@ -271,7 +273,7 @@ static int sunxi_ir_probe(struct platform_device *pdev)
 	 * level
 	 */
 	writel(REG_RXINT_ROI_EN | REG_RXINT_RPEI_EN |
-	       REG_RXINT_RAI_EN | REG_RXINT_RAL(TRIGGER_LEVEL - 1),
+	       REG_RXINT_RAI_EN | REG_RXINT_RAL(ir->fifo_size / 2 - 1),
 	       ir->base + SUNXI_IR_RXINT_REG);
 
 	/* Enable IR Module */
@@ -319,6 +321,7 @@ static int sunxi_ir_remove(struct platform_device *pdev)
 
 static const struct of_device_id sunxi_ir_match[] = {
 	{ .compatible = "allwinner,sun4i-a10-ir", },
+	{ .compatible = "allwinner,sun5i-a13-ir", },
 	{},
 };
 
-- 
2.1.0

[PATCH 6/9] ARM: dts: sun6i: Add ir_clk node

[Hans de Goede]

Add an ir_clk sub-node to the prcm node.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 arch/arm/boot/dts/sun6i-a31.dtsi | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/arm/boot/dts/sun6i-a31.dtsi b/arch/arm/boot/dts/sun6i-a31.dtsi
index a01b215..4aa628b 100644
--- a/arch/arm/boot/dts/sun6i-a31.dtsi
+++ b/arch/arm/boot/dts/sun6i-a31.dtsi
@@ -882,6 +882,13 @@
 						"apb0_i2c";
 			};
 
+			ir_clk: ir_clk {
+				#clock-cells = <0>;
+				compatible = "allwinner,sun6i-a31-ir-clk";
+				clocks = <&osc32k>, <&osc24M>;
+				clock-output-names = "ir";
+			};
+
 			apb0_rst: apb0_rst {
 				compatible = "allwinner,sun6i-a31-clock-reset";
 				#reset-cells = <1>;
-- 
2.1.0

[PATCH 7/9] ARM: dts: sun6i: Add ir node

[Hans de Goede]

Add a node for the ir receiver found on the A31.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 arch/arm/boot/dts/sun6i-a31.dtsi | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/arch/arm/boot/dts/sun6i-a31.dtsi b/arch/arm/boot/dts/sun6i-a31.dtsi
index 4aa628b..d33e758 100644
--- a/arch/arm/boot/dts/sun6i-a31.dtsi
+++ b/arch/arm/boot/dts/sun6i-a31.dtsi
@@ -900,6 +900,16 @@
 			reg = <0x01f01c00 0x300>;
 		};
 
+		ir@01f02000 {
+			compatible = "allwinner,sun5i-a13-ir";
+			clocks = <&apb0_gates 1>, <&ir_clk>;
+			clock-names = "apb", "ir";
+			resets = <&apb0_rst 1>;
+			interrupts = <0 37 4>;
+			reg = <0x01f02000 0x40>;
+			status = "disabled";
+		};
+
 		r_pio: pinctrl@01f02c00 {
 			compatible = "allwinner,sun6i-a31-r-pinctrl";
 			reg = <0x01f02c00 0x400>;
-- 
2.1.0

[PATCH 8/9] ARM: dts: sun6i: Add pinmux settings for the ir pins

[Hans de Goede]

Add pinmux settings for the ir receive pin of the A31.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 arch/arm/boot/dts/sun6i-a31.dtsi | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/arm/boot/dts/sun6i-a31.dtsi b/arch/arm/boot/dts/sun6i-a31.dtsi
index d33e758..90b7537 100644
--- a/arch/arm/boot/dts/sun6i-a31.dtsi
+++ b/arch/arm/boot/dts/sun6i-a31.dtsi
@@ -922,6 +922,13 @@
 			#interrupt-cells = <2>;
 			#size-cells = <0>;
 			#gpio-cells = <3>;
+
+			ir_pins_a: ir@0 {
+				allwinner,pins = "PL4";
+				allwinner,function = "s_ir";
+				allwinner,drive = <0>;
+				allwinner,pull = <0>;
+			};
 		};
 	};
 };
-- 
2.1.0

[PATCH 9/9] ARM: dts: sun6i: Enable ir receiver on the Mele M9

[Hans de Goede]

The Mele M9 has an ir receiver, enable it.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 arch/arm/boot/dts/sun6i-a31-m9.dts | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/arm/boot/dts/sun6i-a31-m9.dts b/arch/arm/boot/dts/sun6i-a31-m9.dts
index 4202c64..94ddf9c 100644
--- a/arch/arm/boot/dts/sun6i-a31-m9.dts
+++ b/arch/arm/boot/dts/sun6i-a31-m9.dts
@@ -83,6 +83,12 @@
 				reg = <1>;
 			};
 		};
+
+		ir@01f02000 {
+			pinctrl-names = "default";
+			pinctrl-0 = <&ir_pins_a>;
+			status = "okay";
+		};
 	};
 
 	leds {
-- 
2.1.0

Re: [PATCH 4/9] rc: sunxi-cir: Add support for an optional reset controller

[Mauro Carvalho Chehab]

Em Thu, 20 Nov 2014 16:55:23 +0100
Hans de Goede <hdegoede@redhat.com> escreveu:

> On sun6i the cir block is attached to the reset controller, add support
> for de-asserting the reset if a reset controller is specified in dt.
> 
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>

As this is meant to be merged via some other tree:

Acked-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>


> ---
>  drivers/media/rc/sunxi-cir.c | 25 +++++++++++++++++++++++--
>  1 file changed, 23 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/media/rc/sunxi-cir.c b/drivers/media/rc/sunxi-cir.c
> index bcee8e1..895fb65 100644
> --- a/drivers/media/rc/sunxi-cir.c
> +++ b/drivers/media/rc/sunxi-cir.c
> @@ -23,6 +23,7 @@
>  #include <linux/interrupt.h>
>  #include <linux/module.h>
>  #include <linux/of_platform.h>
> +#include <linux/reset.h>
>  #include <media/rc-core.h>
>  
>  #define SUNXI_IR_DEV "sunxi-ir"
> @@ -95,6 +96,7 @@ struct sunxi_ir {
>  	int             irq;
>  	struct clk      *clk;
>  	struct clk      *apb_clk;
> +	struct reset_control *rst;
>  	const char      *map_name;
>  };
>  
> @@ -166,15 +168,29 @@ static int sunxi_ir_probe(struct platform_device *pdev)
>  		return PTR_ERR(ir->clk);
>  	}
>  
> +	/* Reset (optional) */
> +	ir->rst = devm_reset_control_get_optional(dev, NULL);
> +	if (IS_ERR(ir->rst)) {
> +		ret = PTR_ERR(ir->rst);
> +		if (ret == -EPROBE_DEFER)
> +			return ret;
> +		ir->rst = NULL;
> +	} else {
> +		ret = reset_control_deassert(ir->rst);
> +		if (ret)
> +			return ret;
> +	}
> +
>  	ret = clk_set_rate(ir->clk, SUNXI_IR_BASE_CLK);
>  	if (ret) {
>  		dev_err(dev, "set ir base clock failed!\n");
> -		return ret;
> +		goto exit_reset_assert;
>  	}
>  
>  	if (clk_prepare_enable(ir->apb_clk)) {
>  		dev_err(dev, "try to enable apb_ir_clk failed\n");
> -		return -EINVAL;
> +		ret = -EINVAL;
> +		goto exit_reset_assert;
>  	}
>  
>  	if (clk_prepare_enable(ir->clk)) {
> @@ -271,6 +287,9 @@ exit_clkdisable_clk:
>  	clk_disable_unprepare(ir->clk);
>  exit_clkdisable_apb_clk:
>  	clk_disable_unprepare(ir->apb_clk);
> +exit_reset_assert:
> +	if (ir->rst)
> +		reset_control_assert(ir->rst);
>  
>  	return ret;
>  }
> @@ -282,6 +301,8 @@ static int sunxi_ir_remove(struct platform_device *pdev)
>  
>  	clk_disable_unprepare(ir->clk);
>  	clk_disable_unprepare(ir->apb_clk);
> +	if (ir->rst)
> +		reset_control_assert(ir->rst);
>  
>  	spin_lock_irqsave(&ir->ir_lock, flags);
>  	/* disable IR IRQ */

Re: [PATCH 5/9] rc: sunxi-cir: Add support for the larger fifo found on sun5i and sun6i

[Mauro Carvalho Chehab]

Em Thu, 20 Nov 2014 16:55:24 +0100
Hans de Goede <hdegoede@redhat.com> escreveu:

> Add support for the larger fifo found on sun5i and sun6i, having a separate
> compatible for the ir found on sun5i & sun6i also is useful if we ever want
> to add ir transmit support, because the sun5i & sun6i version do not have
> transmit support.
> 
> Note this commits also adds checking for the end-of-packet interrupt flag
> (which was already enabled), as the fifo-data-available interrupt flag only
> gets set when the trigger-level is exceeded. So far we've been getting away
> with not doing this because of the low trigger-level, but this is something
> which we should have done since day one.
> 
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>

As this is meant to be merged via some other tree:

Acked-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>


> ---
>  .../devicetree/bindings/media/sunxi-ir.txt          |  2 +-
>  drivers/media/rc/sunxi-cir.c                        | 21 ++++++++++++---------
>  2 files changed, 13 insertions(+), 10 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/media/sunxi-ir.txt b/Documentation/devicetree/bindings/media/sunxi-ir.txt
> index 23dd5ad..5767128 100644
> --- a/Documentation/devicetree/bindings/media/sunxi-ir.txt
> +++ b/Documentation/devicetree/bindings/media/sunxi-ir.txt
> @@ -1,7 +1,7 @@
>  Device-Tree bindings for SUNXI IR controller found in sunXi SoC family
>  
>  Required properties:
> -- compatible	    : should be "allwinner,sun4i-a10-ir";
> +- compatible	    : "allwinner,sun4i-a10-ir" or "allwinner,sun5i-a13-ir"
>  - clocks	    : list of clock specifiers, corresponding to
>  		      entries in clock-names property;
>  - clock-names	    : should contain "apb" and "ir" entries;
> diff --git a/drivers/media/rc/sunxi-cir.c b/drivers/media/rc/sunxi-cir.c
> index 895fb65..559b0e3 100644
> --- a/drivers/media/rc/sunxi-cir.c
> +++ b/drivers/media/rc/sunxi-cir.c
> @@ -56,12 +56,12 @@
>  #define REG_RXINT_RAI_EN		BIT(4)
>  
>  /* Rx FIFO available byte level */
> -#define REG_RXINT_RAL(val)    (((val) << 8) & (GENMASK(11, 8)))
> +#define REG_RXINT_RAL(val)    ((val) << 8)
>  
>  /* Rx Interrupt Status */
>  #define SUNXI_IR_RXSTA_REG    0x30
>  /* RX FIFO Get Available Counter */
> -#define REG_RXSTA_GET_AC(val) (((val) >> 8) & (GENMASK(5, 0)))
> +#define REG_RXSTA_GET_AC(val) (((val) >> 8) & (ir->fifo_size * 2 - 1))
>  /* Clear all interrupt status value */
>  #define REG_RXSTA_CLEARALL    0xff
>  
> @@ -72,10 +72,6 @@
>  /* CIR_REG register idle threshold */
>  #define REG_CIR_ITHR(val)    (((val) << 8) & (GENMASK(15, 8)))
>  
> -/* Hardware supported fifo size */
> -#define SUNXI_IR_FIFO_SIZE    16
> -/* How many messages in FIFO trigger IRQ */
> -#define TRIGGER_LEVEL         8
>  /* Required frequency for IR0 or IR1 clock in CIR mode */
>  #define SUNXI_IR_BASE_CLK     8000000
>  /* Frequency after IR internal divider  */
> @@ -94,6 +90,7 @@ struct sunxi_ir {
>  	struct rc_dev   *rc;
>  	void __iomem    *base;
>  	int             irq;
> +	int		fifo_size;
>  	struct clk      *clk;
>  	struct clk      *apb_clk;
>  	struct reset_control *rst;
> @@ -115,11 +112,11 @@ static irqreturn_t sunxi_ir_irq(int irqno, void *dev_id)
>  	/* clean all pending statuses */
>  	writel(status | REG_RXSTA_CLEARALL, ir->base + SUNXI_IR_RXSTA_REG);
>  
> -	if (status & REG_RXINT_RAI_EN) {
> +	if (status & (REG_RXINT_RAI_EN | REG_RXINT_RPEI_EN)) {
>  		/* How many messages in fifo */
>  		rc  = REG_RXSTA_GET_AC(status);
>  		/* Sanity check */
> -		rc = rc > SUNXI_IR_FIFO_SIZE ? SUNXI_IR_FIFO_SIZE : rc;
> +		rc = rc > ir->fifo_size ? ir->fifo_size : rc;
>  		/* If we have data */
>  		for (cnt = 0; cnt < rc; cnt++) {
>  			/* for each bit in fifo */
> @@ -156,6 +153,11 @@ static int sunxi_ir_probe(struct platform_device *pdev)
>  	if (!ir)
>  		return -ENOMEM;
>  
> +	if (of_device_is_compatible(dn, "allwinner,sun5i-a13-ir"))
> +		ir->fifo_size = 64;
> +	else
> +		ir->fifo_size = 16;
> +
>  	/* Clock */
>  	ir->apb_clk = devm_clk_get(dev, "apb");
>  	if (IS_ERR(ir->apb_clk)) {
> @@ -271,7 +273,7 @@ static int sunxi_ir_probe(struct platform_device *pdev)
>  	 * level
>  	 */
>  	writel(REG_RXINT_ROI_EN | REG_RXINT_RPEI_EN |
> -	       REG_RXINT_RAI_EN | REG_RXINT_RAL(TRIGGER_LEVEL - 1),
> +	       REG_RXINT_RAI_EN | REG_RXINT_RAL(ir->fifo_size / 2 - 1),
>  	       ir->base + SUNXI_IR_RXINT_REG);
>  
>  	/* Enable IR Module */
> @@ -319,6 +321,7 @@ static int sunxi_ir_remove(struct platform_device *pdev)
>  
>  static const struct of_device_id sunxi_ir_match[] = {
>  	{ .compatible = "allwinner,sun4i-a10-ir", },
> +	{ .compatible = "allwinner,sun5i-a13-ir", },
>  	{},
>  };
>  

Re: [linux-sunxi] [PATCH 3/9] clk: sunxi: Add prcm mod0 clock driver

[Chen-Yu Tsai]

Hi,

On Thu, Nov 20, 2014 at 7:55 AM, Hans de Goede <hdegoede@redhat.com> wrote:
> Add a driver for mod0 clocks found in the prcm. Currently there is only
> one mod0 clocks in the prcm, the ir clock.
>
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> ---
>  Documentation/devicetree/bindings/clock/sunxi.txt |  1 +
>  drivers/clk/sunxi/Makefile                        |  2 +-
>  drivers/clk/sunxi/clk-sun6i-prcm-mod0.c           | 63 +++++++++++++++++++++++
>  drivers/mfd/sun6i-prcm.c                          | 14 +++++
>  4 files changed, 79 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/clk/sunxi/clk-sun6i-prcm-mod0.c
>
> diff --git a/Documentation/devicetree/bindings/clock/sunxi.txt b/Documentation/devicetree/bindings/clock/sunxi.txt
> index ed116df..342c75a 100644
> --- a/Documentation/devicetree/bindings/clock/sunxi.txt
> +++ b/Documentation/devicetree/bindings/clock/sunxi.txt
> @@ -56,6 +56,7 @@ Required properties:
>         "allwinner,sun4i-a10-usb-clk" - for usb gates + resets on A10 / A20
>         "allwinner,sun5i-a13-usb-clk" - for usb gates + resets on A13
>         "allwinner,sun6i-a31-usb-clk" - for usb gates + resets on A31
> +       "allwinner,sun6i-a31-ir-clk" - for the ir clock on A31
>
>  Required properties for all clocks:
>  - reg : shall be the control register address for the clock.
> diff --git a/drivers/clk/sunxi/Makefile b/drivers/clk/sunxi/Makefile
> index 7ddc2b5..daf8b1c 100644
> --- a/drivers/clk/sunxi/Makefile
> +++ b/drivers/clk/sunxi/Makefile
> @@ -10,4 +10,4 @@ obj-y += clk-sun8i-mbus.o
>
>  obj-$(CONFIG_MFD_SUN6I_PRCM) += \
>         clk-sun6i-ar100.o clk-sun6i-apb0.o clk-sun6i-apb0-gates.o \
> -       clk-sun8i-apb0.o
> +       clk-sun8i-apb0.o clk-sun6i-prcm-mod0.o
> diff --git a/drivers/clk/sunxi/clk-sun6i-prcm-mod0.c b/drivers/clk/sunxi/clk-sun6i-prcm-mod0.c
> new file mode 100644
> index 0000000..e80f18e
> --- /dev/null
> +++ b/drivers/clk/sunxi/clk-sun6i-prcm-mod0.c
> @@ -0,0 +1,63 @@
> +/*
> + * Allwinner A31 PRCM mod0 clock driver
> + *
> + * Copyright (C) 2014 Hans de Goede <hdegoede@redhat.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/clk-provider.h>
> +#include <linux/clkdev.h>
> +#include <linux/module.h>
> +#include <linux/of_address.h>
> +#include <linux/platform_device.h>
> +
> +#include "clk-factors.h"
> +#include "clk-mod0.h"
> +
> +static const struct of_device_id sun6i_a31_prcm_mod0_clk_dt_ids[] = {
> +       { .compatible = "allwinner,sun6i-a31-ir-clk" },

Could we use a generic name, like "sun6i-a31-prcm-mod0-clk"?
IIRC, there is another one, the module clock for the 1-wire interface.

Same for the DT patches.

ChenYu

> +       { /* sentinel */ }
> +};
> +
> +static DEFINE_SPINLOCK(sun6i_prcm_mod0_lock);
> +
> +static int sun6i_a31_prcm_mod0_clk_probe(struct platform_device *pdev)
> +{
> +       struct device_node *np = pdev->dev.of_node;
> +       struct resource *r;
> +       void __iomem *reg;
> +
> +       if (!np)
> +               return -ENODEV;
> +
> +       r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +       reg = devm_ioremap_resource(&pdev->dev, r);
> +       if (IS_ERR(reg))
> +               return PTR_ERR(reg);
> +
> +       sunxi_factors_register(np, &sun4i_a10_mod0_data,
> +                              &sun6i_prcm_mod0_lock, reg);
> +       return 0;
> +}
> +
> +static struct platform_driver sun6i_a31_prcm_mod0_clk_driver = {
> +       .driver = {
> +               .name = "sun6i-a31-prcm-mod0-clk",
> +               .of_match_table = sun6i_a31_prcm_mod0_clk_dt_ids,
> +       },
> +       .probe = sun6i_a31_prcm_mod0_clk_probe,
> +};
> +module_platform_driver(sun6i_a31_prcm_mod0_clk_driver);
> +
> +MODULE_DESCRIPTION("Allwinner A31 PRCM mod0 clock driver");
> +MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/mfd/sun6i-prcm.c b/drivers/mfd/sun6i-prcm.c
> index 283ab8d..ff1254f 100644
> --- a/drivers/mfd/sun6i-prcm.c
> +++ b/drivers/mfd/sun6i-prcm.c
> @@ -41,6 +41,14 @@ static const struct resource sun6i_a31_apb0_gates_clk_res[] = {
>         },
>  };
>
> +static const struct resource sun6i_a31_ir_clk_res[] = {
> +       {
> +               .start = 0x54,
> +               .end = 0x57,
> +               .flags = IORESOURCE_MEM,
> +       },
> +};
> +
>  static const struct resource sun6i_a31_apb0_rstc_res[] = {
>         {
>                 .start = 0xb0,
> @@ -69,6 +77,12 @@ static const struct mfd_cell sun6i_a31_prcm_subdevs[] = {
>                 .resources = sun6i_a31_apb0_gates_clk_res,
>         },
>         {
> +               .name = "sun6i-a31-ir-clk",
> +               .of_compatible = "allwinner,sun6i-a31-ir-clk",
> +               .num_resources = ARRAY_SIZE(sun6i_a31_ir_clk_res),
> +               .resources = sun6i_a31_ir_clk_res,
> +       },
> +       {
>                 .name = "sun6i-a31-apb0-clock-reset",
>                 .of_compatible = "allwinner,sun6i-a31-clock-reset",
>                 .num_resources = ARRAY_SIZE(sun6i_a31_apb0_rstc_res),
> --
> 2.1.0
>
> --
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Re: [linux-sunxi] [PATCH 3/9] clk: sunxi: Add prcm mod0 clock driver

[Hans de Goede]

Hi,

On 11/20/2014 07:24 PM, Chen-Yu Tsai wrote:
> Hi,
> 
> On Thu, Nov 20, 2014 at 7:55 AM, Hans de Goede <hdegoede@redhat.com> wrote:
>> Add a driver for mod0 clocks found in the prcm. Currently there is only
>> one mod0 clocks in the prcm, the ir clock.
>>
>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>> ---
>>  Documentation/devicetree/bindings/clock/sunxi.txt |  1 +
>>  drivers/clk/sunxi/Makefile                        |  2 +-
>>  drivers/clk/sunxi/clk-sun6i-prcm-mod0.c           | 63 +++++++++++++++++++++++
>>  drivers/mfd/sun6i-prcm.c                          | 14 +++++
>>  4 files changed, 79 insertions(+), 1 deletion(-)
>>  create mode 100644 drivers/clk/sunxi/clk-sun6i-prcm-mod0.c
>>
>> diff --git a/Documentation/devicetree/bindings/clock/sunxi.txt b/Documentation/devicetree/bindings/clock/sunxi.txt
>> index ed116df..342c75a 100644
>> --- a/Documentation/devicetree/bindings/clock/sunxi.txt
>> +++ b/Documentation/devicetree/bindings/clock/sunxi.txt
>> @@ -56,6 +56,7 @@ Required properties:
>>         "allwinner,sun4i-a10-usb-clk" - for usb gates + resets on A10 / A20
>>         "allwinner,sun5i-a13-usb-clk" - for usb gates + resets on A13
>>         "allwinner,sun6i-a31-usb-clk" - for usb gates + resets on A31
>> +       "allwinner,sun6i-a31-ir-clk" - for the ir clock on A31
>>
>>  Required properties for all clocks:
>>  - reg : shall be the control register address for the clock.
>> diff --git a/drivers/clk/sunxi/Makefile b/drivers/clk/sunxi/Makefile
>> index 7ddc2b5..daf8b1c 100644
>> --- a/drivers/clk/sunxi/Makefile
>> +++ b/drivers/clk/sunxi/Makefile
>> @@ -10,4 +10,4 @@ obj-y += clk-sun8i-mbus.o
>>
>>  obj-$(CONFIG_MFD_SUN6I_PRCM) += \
>>         clk-sun6i-ar100.o clk-sun6i-apb0.o clk-sun6i-apb0-gates.o \
>> -       clk-sun8i-apb0.o
>> +       clk-sun8i-apb0.o clk-sun6i-prcm-mod0.o
>> diff --git a/drivers/clk/sunxi/clk-sun6i-prcm-mod0.c b/drivers/clk/sunxi/clk-sun6i-prcm-mod0.c
>> new file mode 100644
>> index 0000000..e80f18e
>> --- /dev/null
>> +++ b/drivers/clk/sunxi/clk-sun6i-prcm-mod0.c
>> @@ -0,0 +1,63 @@
>> +/*
>> + * Allwinner A31 PRCM mod0 clock driver
>> + *
>> + * Copyright (C) 2014 Hans de Goede <hdegoede@redhat.com>
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License as published by
>> + * the Free Software Foundation; either version 2 of the License, or
>> + * (at your option) any later version.
>> + *
>> + * This program is distributed in the hope that it will be useful,
>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>> + * GNU General Public License for more details.
>> + */
>> +
>> +#include <linux/clk-provider.h>
>> +#include <linux/clkdev.h>
>> +#include <linux/module.h>
>> +#include <linux/of_address.h>
>> +#include <linux/platform_device.h>
>> +
>> +#include "clk-factors.h"
>> +#include "clk-mod0.h"
>> +
>> +static const struct of_device_id sun6i_a31_prcm_mod0_clk_dt_ids[] = {
>> +       { .compatible = "allwinner,sun6i-a31-ir-clk" },
> 
> Could we use a generic name, like "sun6i-a31-prcm-mod0-clk"?
> IIRC, there is another one, the module clock for the 1-wire interface.

I wish we could use a generic name, but that does not work for mfd device
subnodes, as the mfd framework attaches resources (such as registers) to
the subnodes based on the compatible.

BTW it seems that that the 1-wire clock is not 100% mod0 clock compatible,
at least the ccmu.h in the allwinner SDK uses a different struct definition
for it.

Regards,

Hans

Re: [linux-sunxi] [PATCH 4/9] rc: sunxi-cir: Add support for an optional reset controller

[Julian Calaby]

Hi Hans,

On Fri, Nov 21, 2014 at 2:55 AM, Hans de Goede <hdegoede@redhat.com> wrote:
> On sun6i the cir block is attached to the reset controller, add support
> for de-asserting the reset if a reset controller is specified in dt.
>
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> ---
>  drivers/media/rc/sunxi-cir.c | 25 +++++++++++++++++++++++--
>  1 file changed, 23 insertions(+), 2 deletions(-)

Shouldn't we be updating the binding documentation?

> diff --git a/drivers/media/rc/sunxi-cir.c b/drivers/media/rc/sunxi-cir.c
> index bcee8e1..895fb65 100644
> --- a/drivers/media/rc/sunxi-cir.c
> +++ b/drivers/media/rc/sunxi-cir.c
> @@ -23,6 +23,7 @@
>  #include <linux/interrupt.h>
>  #include <linux/module.h>
>  #include <linux/of_platform.h>
> +#include <linux/reset.h>
>  #include <media/rc-core.h>
>
>  #define SUNXI_IR_DEV "sunxi-ir"
> @@ -95,6 +96,7 @@ struct sunxi_ir {
>         int             irq;
>         struct clk      *clk;
>         struct clk      *apb_clk;
> +       struct reset_control *rst;
>         const char      *map_name;
>  };
>
> @@ -166,15 +168,29 @@ static int sunxi_ir_probe(struct platform_device *pdev)
>                 return PTR_ERR(ir->clk);
>         }
>
> +       /* Reset (optional) */
> +       ir->rst = devm_reset_control_get_optional(dev, NULL);
> +       if (IS_ERR(ir->rst)) {
> +               ret = PTR_ERR(ir->rst);
> +               if (ret == -EPROBE_DEFER)
> +                       return ret;
> +               ir->rst = NULL;
> +       } else {
> +               ret = reset_control_deassert(ir->rst);
> +               if (ret)
> +                       return ret;
> +       }
> +
>         ret = clk_set_rate(ir->clk, SUNXI_IR_BASE_CLK);
>         if (ret) {
>                 dev_err(dev, "set ir base clock failed!\n");
> -               return ret;
> +               goto exit_reset_assert;
>         }
>
>         if (clk_prepare_enable(ir->apb_clk)) {
>                 dev_err(dev, "try to enable apb_ir_clk failed\n");
> -               return -EINVAL;
> +               ret = -EINVAL;
> +               goto exit_reset_assert;
>         }
>
>         if (clk_prepare_enable(ir->clk)) {
> @@ -271,6 +287,9 @@ exit_clkdisable_clk:
>         clk_disable_unprepare(ir->clk);
>  exit_clkdisable_apb_clk:
>         clk_disable_unprepare(ir->apb_clk);
> +exit_reset_assert:
> +       if (ir->rst)
> +               reset_control_assert(ir->rst);
>
>         return ret;
>  }
> @@ -282,6 +301,8 @@ static int sunxi_ir_remove(struct platform_device *pdev)
>
>         clk_disable_unprepare(ir->clk);
>         clk_disable_unprepare(ir->apb_clk);
> +       if (ir->rst)
> +               reset_control_assert(ir->rst);
>
>         spin_lock_irqsave(&ir->ir_lock, flags);
>         /* disable IR IRQ */
> --
> 2.1.0
>
> --
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> To unsubscribe from this group and stop receiving emails from it, send an email to linux-sunxi+unsubscribe@googlegroups.com.
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-- 
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Profile: http://www.google.com/profiles/julian.calaby/

Re: [PATCH 5/9] rc: sunxi-cir: Add support for the larger fifo found on sun5i and sun6i

[Maxime Ripard]

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Hi Mauro,

On Thu, Nov 20, 2014 at 02:28:56PM -0200, Mauro Carvalho Chehab wrote:
> Em Thu, 20 Nov 2014 16:55:24 +0100
> Hans de Goede <hdegoede@redhat.com> escreveu:
> 
> > Add support for the larger fifo found on sun5i and sun6i, having a separate
> > compatible for the ir found on sun5i & sun6i also is useful if we ever want
> > to add ir transmit support, because the sun5i & sun6i version do not have
> > transmit support.
> > 
> > Note this commits also adds checking for the end-of-packet interrupt flag
> > (which was already enabled), as the fifo-data-available interrupt flag only
> > gets set when the trigger-level is exceeded. So far we've been getting away
> > with not doing this because of the low trigger-level, but this is something
> > which we should have done since day one.
> > 
> > Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> 
> As this is meant to be merged via some other tree:
> 
> Acked-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

I think merging it through your tree would be just fine.

Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>

Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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Re: [PATCH 1/9] clk: sunxi: Give sunxi_factors_register a registers parameter

[Maxime Ripard]

[-- Attachment #1: Type: text/plain, Size: 3783 bytes --]

Hi Hans,

On Thu, Nov 20, 2014 at 04:55:20PM +0100, Hans de Goede wrote:
> Before this commit sunxi_factors_register uses of_iomap(node, 0) to get
> the clk registers. The sun6i prcm has factor clocks, for which we want to
> use sunxi_factors_register, but of_iomap(node, 0) does not work for the prcm
> factor clocks, because the prcm uses the mfd framework, so the registers
> are not part of the dt-node, instead they are added to the platform_device,
> as platform_device resources.
> 
> This commit makes getting the registers the callers duty, so that
> sunxi_factors_register can be used with mfd instantiated platform device too.
> 
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>

Funny, I was thinking of doing exactly the same thing for MMC clocks :)

> ---
>  drivers/clk/sunxi/clk-factors.c    | 10 ++++------
>  drivers/clk/sunxi/clk-factors.h    |  7 ++++---
>  drivers/clk/sunxi/clk-mod0.c       |  6 ++++--
>  drivers/clk/sunxi/clk-sun8i-mbus.c |  2 +-
>  drivers/clk/sunxi/clk-sunxi.c      |  3 ++-
>  5 files changed, 15 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/clk/sunxi/clk-factors.c b/drivers/clk/sunxi/clk-factors.c
> index f83ba09..fc4f4b5 100644
> --- a/drivers/clk/sunxi/clk-factors.c
> +++ b/drivers/clk/sunxi/clk-factors.c
> @@ -156,9 +156,10 @@ static const struct clk_ops clk_factors_ops = {
>  	.set_rate = clk_factors_set_rate,
>  };
>  
> -struct clk * __init sunxi_factors_register(struct device_node *node,
> -					   const struct factors_data *data,
> -					   spinlock_t *lock)
> +struct clk *sunxi_factors_register(struct device_node *node,
> +				   const struct factors_data *data,
> +				   spinlock_t *lock,
> +				   void __iomem *reg)
>  {
>  	struct clk *clk;
>  	struct clk_factors *factors;
> @@ -168,11 +169,8 @@ struct clk * __init sunxi_factors_register(struct device_node *node,
>  	struct clk_hw *mux_hw = NULL;
>  	const char *clk_name = node->name;
>  	const char *parents[FACTORS_MAX_PARENTS];
> -	void __iomem *reg;
>  	int i = 0;
>  
> -	reg = of_iomap(node, 0);
> -
>  	/* if we have a mux, we will have >1 parents */
>  	while (i < FACTORS_MAX_PARENTS &&
>  	       (parents[i] = of_clk_get_parent_name(node, i)) != NULL)
> diff --git a/drivers/clk/sunxi/clk-factors.h b/drivers/clk/sunxi/clk-factors.h
> index 9913840..1f5526d 100644
> --- a/drivers/clk/sunxi/clk-factors.h
> +++ b/drivers/clk/sunxi/clk-factors.h
> @@ -37,8 +37,9 @@ struct clk_factors {
>  	spinlock_t *lock;
>  };
>  
> -struct clk * __init sunxi_factors_register(struct device_node *node,
> -					   const struct factors_data *data,
> -					   spinlock_t *lock);
> +struct clk *sunxi_factors_register(struct device_node *node,
> +				   const struct factors_data *data,
> +				   spinlock_t *lock,
> +				   void __iomem *reg);

Why are you dropping the __init there?

>  
>  #endif
> diff --git a/drivers/clk/sunxi/clk-mod0.c b/drivers/clk/sunxi/clk-mod0.c
> index 4a56385..9530833 100644
> --- a/drivers/clk/sunxi/clk-mod0.c
> +++ b/drivers/clk/sunxi/clk-mod0.c
> @@ -78,7 +78,8 @@ static DEFINE_SPINLOCK(sun4i_a10_mod0_lock);
>  
>  static void __init sun4i_a10_mod0_setup(struct device_node *node)
>  {
> -	sunxi_factors_register(node, &sun4i_a10_mod0_data, &sun4i_a10_mod0_lock);
> +	sunxi_factors_register(node, &sun4i_a10_mod0_data,
> +			       &sun4i_a10_mod0_lock, of_iomap(node, 0));

As of_iomap can fail, I'd rather check the returned value before
calling sunxi_factors_register.

I know it wasn't done before, but it's the right thing to do, as it
would lead to an instant crash if that fails.

Thanks!
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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Re: [PATCH 5/9] rc: sunxi-cir: Add support for the larger fifo found on sun5i and sun6i

[Hans de Goede]

Hi,

On 11/21/2014 09:26 AM, Maxime Ripard wrote:
> Hi Mauro,
> 
> On Thu, Nov 20, 2014 at 02:28:56PM -0200, Mauro Carvalho Chehab wrote:
>> Em Thu, 20 Nov 2014 16:55:24 +0100
>> Hans de Goede <hdegoede@redhat.com> escreveu:
>>
>>> Add support for the larger fifo found on sun5i and sun6i, having a separate
>>> compatible for the ir found on sun5i & sun6i also is useful if we ever want
>>> to add ir transmit support, because the sun5i & sun6i version do not have
>>> transmit support.
>>>
>>> Note this commits also adds checking for the end-of-packet interrupt flag
>>> (which was already enabled), as the fifo-data-available interrupt flag only
>>> gets set when the trigger-level is exceeded. So far we've been getting away
>>> with not doing this because of the low trigger-level, but this is something
>>> which we should have done since day one.
>>>
>>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>>
>> As this is meant to be merged via some other tree:
>>
>> Acked-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
> 
> I think merging it through your tree would be just fine.
> 
> Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>

Heh, I was thinking it would be best if it went through Maxime's tree because
it also has some deps on new clk stuff (well the dts have deps on that), but either
way works for me.

Maxime if you want this go through Mauro's tree, I can send a pull-req to Mauro
(I'm a linux-media sub-maintainer), so if that is the case let me know and I'll
prepare a pull-req (after fixing the missing reset documentation in the bindings).

Regards,

Hans

Re: [PATCH 1/9] clk: sunxi: Give sunxi_factors_register a registers parameter

[Hans de Goede]

Hi,

On 11/21/2014 09:35 AM, Maxime Ripard wrote:
> Hi Hans,
> 
> On Thu, Nov 20, 2014 at 04:55:20PM +0100, Hans de Goede wrote:
>> Before this commit sunxi_factors_register uses of_iomap(node, 0) to get
>> the clk registers. The sun6i prcm has factor clocks, for which we want to
>> use sunxi_factors_register, but of_iomap(node, 0) does not work for the prcm
>> factor clocks, because the prcm uses the mfd framework, so the registers
>> are not part of the dt-node, instead they are added to the platform_device,
>> as platform_device resources.
>>
>> This commit makes getting the registers the callers duty, so that
>> sunxi_factors_register can be used with mfd instantiated platform device too.
>>
>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> 
> Funny, I was thinking of doing exactly the same thing for MMC clocks :)
> 
>> ---
>>  drivers/clk/sunxi/clk-factors.c    | 10 ++++------
>>  drivers/clk/sunxi/clk-factors.h    |  7 ++++---
>>  drivers/clk/sunxi/clk-mod0.c       |  6 ++++--
>>  drivers/clk/sunxi/clk-sun8i-mbus.c |  2 +-
>>  drivers/clk/sunxi/clk-sunxi.c      |  3 ++-
>>  5 files changed, 15 insertions(+), 13 deletions(-)
>>
>> diff --git a/drivers/clk/sunxi/clk-factors.c b/drivers/clk/sunxi/clk-factors.c
>> index f83ba09..fc4f4b5 100644
>> --- a/drivers/clk/sunxi/clk-factors.c
>> +++ b/drivers/clk/sunxi/clk-factors.c
>> @@ -156,9 +156,10 @@ static const struct clk_ops clk_factors_ops = {
>>  	.set_rate = clk_factors_set_rate,
>>  };
>>  
>> -struct clk * __init sunxi_factors_register(struct device_node *node,
>> -					   const struct factors_data *data,
>> -					   spinlock_t *lock)
>> +struct clk *sunxi_factors_register(struct device_node *node,
>> +				   const struct factors_data *data,
>> +				   spinlock_t *lock,
>> +				   void __iomem *reg)
>>  {
>>  	struct clk *clk;
>>  	struct clk_factors *factors;
>> @@ -168,11 +169,8 @@ struct clk * __init sunxi_factors_register(struct device_node *node,
>>  	struct clk_hw *mux_hw = NULL;
>>  	const char *clk_name = node->name;
>>  	const char *parents[FACTORS_MAX_PARENTS];
>> -	void __iomem *reg;
>>  	int i = 0;
>>  
>> -	reg = of_iomap(node, 0);
>> -
>>  	/* if we have a mux, we will have >1 parents */
>>  	while (i < FACTORS_MAX_PARENTS &&
>>  	       (parents[i] = of_clk_get_parent_name(node, i)) != NULL)
>> diff --git a/drivers/clk/sunxi/clk-factors.h b/drivers/clk/sunxi/clk-factors.h
>> index 9913840..1f5526d 100644
>> --- a/drivers/clk/sunxi/clk-factors.h
>> +++ b/drivers/clk/sunxi/clk-factors.h
>> @@ -37,8 +37,9 @@ struct clk_factors {
>>  	spinlock_t *lock;
>>  };
>>  
>> -struct clk * __init sunxi_factors_register(struct device_node *node,
>> -					   const struct factors_data *data,
>> -					   spinlock_t *lock);
>> +struct clk *sunxi_factors_register(struct device_node *node,
>> +				   const struct factors_data *data,
>> +				   spinlock_t *lock,
>> +				   void __iomem *reg);
> 
> Why are you dropping the __init there?

Because it is going to be used from mfd instantiation, so from a platform_dev
probe function which is not __init.

> 
>>  
>>  #endif
>> diff --git a/drivers/clk/sunxi/clk-mod0.c b/drivers/clk/sunxi/clk-mod0.c
>> index 4a56385..9530833 100644
>> --- a/drivers/clk/sunxi/clk-mod0.c
>> +++ b/drivers/clk/sunxi/clk-mod0.c
>> @@ -78,7 +78,8 @@ static DEFINE_SPINLOCK(sun4i_a10_mod0_lock);
>>  
>>  static void __init sun4i_a10_mod0_setup(struct device_node *node)
>>  {
>> -	sunxi_factors_register(node, &sun4i_a10_mod0_data, &sun4i_a10_mod0_lock);
>> +	sunxi_factors_register(node, &sun4i_a10_mod0_data,
>> +			       &sun4i_a10_mod0_lock, of_iomap(node, 0));
> 
> As of_iomap can fail, I'd rather check the returned value before
> calling sunxi_factors_register.
> 
> I know it wasn't done before, but it's the right thing to do, as it
> would lead to an instant crash if that fails.

Ok, I'll wait for you to review the rest of the series and then do a v2 of the
patch-set with this fixed (as time permits).

Regards,

Hans

Re: [PATCH 3/9] clk: sunxi: Add prcm mod0 clock driver

[Maxime Ripard]

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Hi,

On Thu, Nov 20, 2014 at 04:55:22PM +0100, Hans de Goede wrote:
> Add a driver for mod0 clocks found in the prcm. Currently there is only
> one mod0 clocks in the prcm, the ir clock.
> 
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> ---
>  Documentation/devicetree/bindings/clock/sunxi.txt |  1 +
>  drivers/clk/sunxi/Makefile                        |  2 +-
>  drivers/clk/sunxi/clk-sun6i-prcm-mod0.c           | 63 +++++++++++++++++++++++
>  drivers/mfd/sun6i-prcm.c                          | 14 +++++
>  4 files changed, 79 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/clk/sunxi/clk-sun6i-prcm-mod0.c
> 
> diff --git a/Documentation/devicetree/bindings/clock/sunxi.txt b/Documentation/devicetree/bindings/clock/sunxi.txt
> index ed116df..342c75a 100644
> --- a/Documentation/devicetree/bindings/clock/sunxi.txt
> +++ b/Documentation/devicetree/bindings/clock/sunxi.txt
> @@ -56,6 +56,7 @@ Required properties:
>  	"allwinner,sun4i-a10-usb-clk" - for usb gates + resets on A10 / A20
>  	"allwinner,sun5i-a13-usb-clk" - for usb gates + resets on A13
>  	"allwinner,sun6i-a31-usb-clk" - for usb gates + resets on A31
> +	"allwinner,sun6i-a31-ir-clk" - for the ir clock on A31
>  
>  Required properties for all clocks:
>  - reg : shall be the control register address for the clock.
> diff --git a/drivers/clk/sunxi/Makefile b/drivers/clk/sunxi/Makefile
> index 7ddc2b5..daf8b1c 100644
> --- a/drivers/clk/sunxi/Makefile
> +++ b/drivers/clk/sunxi/Makefile
> @@ -10,4 +10,4 @@ obj-y += clk-sun8i-mbus.o
>  
>  obj-$(CONFIG_MFD_SUN6I_PRCM) += \
>  	clk-sun6i-ar100.o clk-sun6i-apb0.o clk-sun6i-apb0-gates.o \
> -	clk-sun8i-apb0.o
> +	clk-sun8i-apb0.o clk-sun6i-prcm-mod0.o
> diff --git a/drivers/clk/sunxi/clk-sun6i-prcm-mod0.c b/drivers/clk/sunxi/clk-sun6i-prcm-mod0.c
> new file mode 100644
> index 0000000..e80f18e
> --- /dev/null
> +++ b/drivers/clk/sunxi/clk-sun6i-prcm-mod0.c
> @@ -0,0 +1,63 @@
> +/*
> + * Allwinner A31 PRCM mod0 clock driver
> + *
> + * Copyright (C) 2014 Hans de Goede <hdegoede@redhat.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/clk-provider.h>
> +#include <linux/clkdev.h>
> +#include <linux/module.h>
> +#include <linux/of_address.h>
> +#include <linux/platform_device.h>
> +
> +#include "clk-factors.h"
> +#include "clk-mod0.h"
> +
> +static const struct of_device_id sun6i_a31_prcm_mod0_clk_dt_ids[] = {
> +	{ .compatible = "allwinner,sun6i-a31-ir-clk" },
> +	{ /* sentinel */ }
> +};
> +
> +static DEFINE_SPINLOCK(sun6i_prcm_mod0_lock);
> +
> +static int sun6i_a31_prcm_mod0_clk_probe(struct platform_device *pdev)
> +{
> +	struct device_node *np = pdev->dev.of_node;
> +	struct resource *r;
> +	void __iomem *reg;
> +
> +	if (!np)
> +		return -ENODEV;
> +
> +	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	reg = devm_ioremap_resource(&pdev->dev, r);
> +	if (IS_ERR(reg))
> +		return PTR_ERR(reg);
> +
> +	sunxi_factors_register(np, &sun4i_a10_mod0_data,
> +			       &sun6i_prcm_mod0_lock, reg);
> +	return 0;
> +}
> +
> +static struct platform_driver sun6i_a31_prcm_mod0_clk_driver = {
> +	.driver = {
> +		.name = "sun6i-a31-prcm-mod0-clk",
> +		.of_match_table = sun6i_a31_prcm_mod0_clk_dt_ids,
> +	},
> +	.probe = sun6i_a31_prcm_mod0_clk_probe,
> +};
> +module_platform_driver(sun6i_a31_prcm_mod0_clk_driver);
> +
> +MODULE_DESCRIPTION("Allwinner A31 PRCM mod0 clock driver");
> +MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
> +MODULE_LICENSE("GPL");

I don't think this is the right approach, mainly for two reasons: the
compatible shouldn't change, and you're basically duplicating code
there.

I understand that you need the new compatible in order to avoid a
double probing: one by CLK_OF_DECLARE, and one by the usual mechanism,
and that also implies the second reason.

However, as those are not critical clocks that need to be here early
at boot, you can also fix this by turning the mod0 driver into a
platform driver itself. The compatible will be kept, the driver will
be the same.

The only thing we need to pay attention to is how "client" drivers
react when they cannot grab their clock. They should return
-EPROBE_DEFER, but that remains to be checked.

Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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Re: [PATCH 4/9] rc: sunxi-cir: Add support for an optional reset controller

[Maxime Ripard]

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Hi Mauro,

On Thu, Nov 20, 2014 at 02:28:31PM -0200, Mauro Carvalho Chehab wrote:
> Em Thu, 20 Nov 2014 16:55:23 +0100
> Hans de Goede <hdegoede@redhat.com> escreveu:
> 
> > On sun6i the cir block is attached to the reset controller, add support
> > for de-asserting the reset if a reset controller is specified in dt.
> > 
> > Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> 
> As this is meant to be merged via some other tree:
> 
> Acked-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

Again, I think it'll be perfectly fine in your tree :)

Once the documentation is updated,
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>

Thanks,
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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Re: [PATCH 3/9] clk: sunxi: Add prcm mod0 clock driver

[Hans de Goede]

Hi,

On 11/21/2014 09:49 AM, Maxime Ripard wrote:
> Hi,
> 
> On Thu, Nov 20, 2014 at 04:55:22PM +0100, Hans de Goede wrote:
>> Add a driver for mod0 clocks found in the prcm. Currently there is only
>> one mod0 clocks in the prcm, the ir clock.
>>
>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>> ---
>>  Documentation/devicetree/bindings/clock/sunxi.txt |  1 +
>>  drivers/clk/sunxi/Makefile                        |  2 +-
>>  drivers/clk/sunxi/clk-sun6i-prcm-mod0.c           | 63 +++++++++++++++++++++++
>>  drivers/mfd/sun6i-prcm.c                          | 14 +++++
>>  4 files changed, 79 insertions(+), 1 deletion(-)
>>  create mode 100644 drivers/clk/sunxi/clk-sun6i-prcm-mod0.c
>>
>> diff --git a/Documentation/devicetree/bindings/clock/sunxi.txt b/Documentation/devicetree/bindings/clock/sunxi.txt
>> index ed116df..342c75a 100644
>> --- a/Documentation/devicetree/bindings/clock/sunxi.txt
>> +++ b/Documentation/devicetree/bindings/clock/sunxi.txt
>> @@ -56,6 +56,7 @@ Required properties:
>>  	"allwinner,sun4i-a10-usb-clk" - for usb gates + resets on A10 / A20
>>  	"allwinner,sun5i-a13-usb-clk" - for usb gates + resets on A13
>>  	"allwinner,sun6i-a31-usb-clk" - for usb gates + resets on A31
>> +	"allwinner,sun6i-a31-ir-clk" - for the ir clock on A31
>>  
>>  Required properties for all clocks:
>>  - reg : shall be the control register address for the clock.
>> diff --git a/drivers/clk/sunxi/Makefile b/drivers/clk/sunxi/Makefile
>> index 7ddc2b5..daf8b1c 100644
>> --- a/drivers/clk/sunxi/Makefile
>> +++ b/drivers/clk/sunxi/Makefile
>> @@ -10,4 +10,4 @@ obj-y += clk-sun8i-mbus.o
>>  
>>  obj-$(CONFIG_MFD_SUN6I_PRCM) += \
>>  	clk-sun6i-ar100.o clk-sun6i-apb0.o clk-sun6i-apb0-gates.o \
>> -	clk-sun8i-apb0.o
>> +	clk-sun8i-apb0.o clk-sun6i-prcm-mod0.o
>> diff --git a/drivers/clk/sunxi/clk-sun6i-prcm-mod0.c b/drivers/clk/sunxi/clk-sun6i-prcm-mod0.c
>> new file mode 100644
>> index 0000000..e80f18e
>> --- /dev/null
>> +++ b/drivers/clk/sunxi/clk-sun6i-prcm-mod0.c
>> @@ -0,0 +1,63 @@
>> +/*
>> + * Allwinner A31 PRCM mod0 clock driver
>> + *
>> + * Copyright (C) 2014 Hans de Goede <hdegoede@redhat.com>
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License as published by
>> + * the Free Software Foundation; either version 2 of the License, or
>> + * (at your option) any later version.
>> + *
>> + * This program is distributed in the hope that it will be useful,
>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>> + * GNU General Public License for more details.
>> + */
>> +
>> +#include <linux/clk-provider.h>
>> +#include <linux/clkdev.h>
>> +#include <linux/module.h>
>> +#include <linux/of_address.h>
>> +#include <linux/platform_device.h>
>> +
>> +#include "clk-factors.h"
>> +#include "clk-mod0.h"
>> +
>> +static const struct of_device_id sun6i_a31_prcm_mod0_clk_dt_ids[] = {
>> +	{ .compatible = "allwinner,sun6i-a31-ir-clk" },
>> +	{ /* sentinel */ }
>> +};
>> +
>> +static DEFINE_SPINLOCK(sun6i_prcm_mod0_lock);
>> +
>> +static int sun6i_a31_prcm_mod0_clk_probe(struct platform_device *pdev)
>> +{
>> +	struct device_node *np = pdev->dev.of_node;
>> +	struct resource *r;
>> +	void __iomem *reg;
>> +
>> +	if (!np)
>> +		return -ENODEV;
>> +
>> +	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> +	reg = devm_ioremap_resource(&pdev->dev, r);
>> +	if (IS_ERR(reg))
>> +		return PTR_ERR(reg);
>> +
>> +	sunxi_factors_register(np, &sun4i_a10_mod0_data,
>> +			       &sun6i_prcm_mod0_lock, reg);
>> +	return 0;
>> +}
>> +
>> +static struct platform_driver sun6i_a31_prcm_mod0_clk_driver = {
>> +	.driver = {
>> +		.name = "sun6i-a31-prcm-mod0-clk",
>> +		.of_match_table = sun6i_a31_prcm_mod0_clk_dt_ids,
>> +	},
>> +	.probe = sun6i_a31_prcm_mod0_clk_probe,
>> +};
>> +module_platform_driver(sun6i_a31_prcm_mod0_clk_driver);
>> +
>> +MODULE_DESCRIPTION("Allwinner A31 PRCM mod0 clock driver");
>> +MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
>> +MODULE_LICENSE("GPL");
> 
> I don't think this is the right approach, mainly for two reasons: the
> compatible shouldn't change, and you're basically duplicating code
> there.
> 
> I understand that you need the new compatible in order to avoid a
> double probing: one by CLK_OF_DECLARE, and one by the usual mechanism,
> and that also implies the second reason.

Not only for that, we need a new compatible also because the mfd framework
needs a separate compatible per sub-node as that is how it finds nodes
to attach to the platform devices, so we need a new compatible anyways,
with your make the mod0 clock driver a platform driver solution we could
use:

	compatible = "allwinner,sun6i-a31-ir-clk", "allwinner,sun4i-a10-mod0-clk";

To work around this, but there are other problems, your make mod0clk a
platform driver solution cannot work because the clocks node in the dtsi
is not simple-bus compatible, so no platform-devs will be instantiated for
the clocks there.

Besides the compatible (which as said we need a separate one anyways),
your other worry is code duplication, but I've avoided that as much
as possible already, the new drivers/clk/sunxi/clk-sun6i-prcm-mod0.c is
just a very thin wrapper, waying in with all of 63 lines including
16 lines GPL header.

So sorry, I disagree I believe that this is the best solution.

> However, as those are not critical clocks that need to be here early
> at boot, you can also fix this by turning the mod0 driver into a
> platform driver itself. The compatible will be kept, the driver will
> be the same.
> 
> The only thing we need to pay attention to is how "client" drivers
> react when they cannot grab their clock. They should return
> -EPROBE_DEFER, but that remains to be checked.

-EPROBE_DEFER is yet another reason to not make mod0-clk a platform
driver. Yes drivers should be able to handle this, but it is a pain,
and the more we use it the more pain it is. Also it makes booting a lot
slower as any driver using a mod0 clk now, will not complete its probe
until all the other drivers are done probing and the late_initcall
which starts the deferred-probe wq runs.

Regards,

Hans

Re: [PATCH 5/9] rc: sunxi-cir: Add support for the larger fifo found on sun5i and sun6i

[Maxime Ripard]

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On Fri, Nov 21, 2014 at 09:42:09AM +0100, Hans de Goede wrote:
> Hi,
> 
> On 11/21/2014 09:26 AM, Maxime Ripard wrote:
> > Hi Mauro,
> > 
> > On Thu, Nov 20, 2014 at 02:28:56PM -0200, Mauro Carvalho Chehab wrote:
> >> Em Thu, 20 Nov 2014 16:55:24 +0100
> >> Hans de Goede <hdegoede@redhat.com> escreveu:
> >>
> >>> Add support for the larger fifo found on sun5i and sun6i, having a separate
> >>> compatible for the ir found on sun5i & sun6i also is useful if we ever want
> >>> to add ir transmit support, because the sun5i & sun6i version do not have
> >>> transmit support.
> >>>
> >>> Note this commits also adds checking for the end-of-packet interrupt flag
> >>> (which was already enabled), as the fifo-data-available interrupt flag only
> >>> gets set when the trigger-level is exceeded. So far we've been getting away
> >>> with not doing this because of the low trigger-level, but this is something
> >>> which we should have done since day one.
> >>>
> >>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> >>
> >> As this is meant to be merged via some other tree:
> >>
> >> Acked-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
> > 
> > I think merging it through your tree would be just fine.
> > 
> > Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> 
> Heh, I was thinking it would be best if it went through Maxime's tree because
> it also has some deps on new clk stuff (well the dts have deps on that), but either
> way works for me.
> 
> Maxime if you want this go through Mauro's tree, I can send a pull-req to Mauro
> (I'm a linux-media sub-maintainer), so if that is the case let me know and I'll
> prepare a pull-req (after fixing the missing reset documentation in the bindings).

So much for not reading the cover letter... Sorry.

We're getting quite close to the end of the ARM merge window, and I
got a couple comments, Lee hasn't commented yet, so I'd say it's a bit
too late for this to come in.

If Mauro is happy with the current patches for him, it's completely
fine to merge it through his tree. The DTS can wait.

Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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Re: [PATCH 5/9] rc: sunxi-cir: Add support for the larger fifo found on sun5i and sun6i

[Hans de Goede]

Hi,

On 11/21/2014 10:59 AM, Maxime Ripard wrote:
> On Fri, Nov 21, 2014 at 09:42:09AM +0100, Hans de Goede wrote:
>> Hi,
>>
>> On 11/21/2014 09:26 AM, Maxime Ripard wrote:
>>> Hi Mauro,
>>>
>>> On Thu, Nov 20, 2014 at 02:28:56PM -0200, Mauro Carvalho Chehab wrote:
>>>> Em Thu, 20 Nov 2014 16:55:24 +0100
>>>> Hans de Goede <hdegoede@redhat.com> escreveu:
>>>>
>>>>> Add support for the larger fifo found on sun5i and sun6i, having a separate
>>>>> compatible for the ir found on sun5i & sun6i also is useful if we ever want
>>>>> to add ir transmit support, because the sun5i & sun6i version do not have
>>>>> transmit support.
>>>>>
>>>>> Note this commits also adds checking for the end-of-packet interrupt flag
>>>>> (which was already enabled), as the fifo-data-available interrupt flag only
>>>>> gets set when the trigger-level is exceeded. So far we've been getting away
>>>>> with not doing this because of the low trigger-level, but this is something
>>>>> which we should have done since day one.
>>>>>
>>>>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>>>>
>>>> As this is meant to be merged via some other tree:
>>>>
>>>> Acked-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
>>>
>>> I think merging it through your tree would be just fine.
>>>
>>> Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
>>
>> Heh, I was thinking it would be best if it went through Maxime's tree because
>> it also has some deps on new clk stuff (well the dts have deps on that), but either
>> way works for me.
>>
>> Maxime if you want this go through Mauro's tree, I can send a pull-req to Mauro
>> (I'm a linux-media sub-maintainer), so if that is the case let me know and I'll
>> prepare a pull-req (after fixing the missing reset documentation in the bindings).
> 
> So much for not reading the cover letter... Sorry.
> 
> We're getting quite close to the end of the ARM merge window, and I
> got a couple comments, Lee hasn't commented yet, so I'd say it's a bit
> too late for this to come in.

Oh, but this was not intended for 3.19, this can wait till 3.20 from my pov,
sorry if that was not clear. I was assuming that the merge window was more
or less closed already, so that this going into 3.20 was expected.

Regrrds,

Hans

Re: [PATCH 1/9] clk: sunxi: Give sunxi_factors_register a registers parameter

[Maxime Ripard]

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On Fri, Nov 21, 2014 at 09:44:51AM +0100, Hans de Goede wrote:
> Hi,
> 
> On 11/21/2014 09:35 AM, Maxime Ripard wrote:
> > Hi Hans,
> > 
> > On Thu, Nov 20, 2014 at 04:55:20PM +0100, Hans de Goede wrote:
> >> Before this commit sunxi_factors_register uses of_iomap(node, 0) to get
> >> the clk registers. The sun6i prcm has factor clocks, for which we want to
> >> use sunxi_factors_register, but of_iomap(node, 0) does not work for the prcm
> >> factor clocks, because the prcm uses the mfd framework, so the registers
> >> are not part of the dt-node, instead they are added to the platform_device,
> >> as platform_device resources.
> >>
> >> This commit makes getting the registers the callers duty, so that
> >> sunxi_factors_register can be used with mfd instantiated platform device too.
> >>
> >> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> > 
> > Funny, I was thinking of doing exactly the same thing for MMC clocks :)
> > 
> >> ---
> >>  drivers/clk/sunxi/clk-factors.c    | 10 ++++------
> >>  drivers/clk/sunxi/clk-factors.h    |  7 ++++---
> >>  drivers/clk/sunxi/clk-mod0.c       |  6 ++++--
> >>  drivers/clk/sunxi/clk-sun8i-mbus.c |  2 +-
> >>  drivers/clk/sunxi/clk-sunxi.c      |  3 ++-
> >>  5 files changed, 15 insertions(+), 13 deletions(-)
> >>
> >> diff --git a/drivers/clk/sunxi/clk-factors.c b/drivers/clk/sunxi/clk-factors.c
> >> index f83ba09..fc4f4b5 100644
> >> --- a/drivers/clk/sunxi/clk-factors.c
> >> +++ b/drivers/clk/sunxi/clk-factors.c
> >> @@ -156,9 +156,10 @@ static const struct clk_ops clk_factors_ops = {
> >>  	.set_rate = clk_factors_set_rate,
> >>  };
> >>  
> >> -struct clk * __init sunxi_factors_register(struct device_node *node,
> >> -					   const struct factors_data *data,
> >> -					   spinlock_t *lock)
> >> +struct clk *sunxi_factors_register(struct device_node *node,
> >> +				   const struct factors_data *data,
> >> +				   spinlock_t *lock,
> >> +				   void __iomem *reg)
> >>  {
> >>  	struct clk *clk;
> >>  	struct clk_factors *factors;
> >> @@ -168,11 +169,8 @@ struct clk * __init sunxi_factors_register(struct device_node *node,
> >>  	struct clk_hw *mux_hw = NULL;
> >>  	const char *clk_name = node->name;
> >>  	const char *parents[FACTORS_MAX_PARENTS];
> >> -	void __iomem *reg;
> >>  	int i = 0;
> >>  
> >> -	reg = of_iomap(node, 0);
> >> -
> >>  	/* if we have a mux, we will have >1 parents */
> >>  	while (i < FACTORS_MAX_PARENTS &&
> >>  	       (parents[i] = of_clk_get_parent_name(node, i)) != NULL)
> >> diff --git a/drivers/clk/sunxi/clk-factors.h b/drivers/clk/sunxi/clk-factors.h
> >> index 9913840..1f5526d 100644
> >> --- a/drivers/clk/sunxi/clk-factors.h
> >> +++ b/drivers/clk/sunxi/clk-factors.h
> >> @@ -37,8 +37,9 @@ struct clk_factors {
> >>  	spinlock_t *lock;
> >>  };
> >>  
> >> -struct clk * __init sunxi_factors_register(struct device_node *node,
> >> -					   const struct factors_data *data,
> >> -					   spinlock_t *lock);
> >> +struct clk *sunxi_factors_register(struct device_node *node,
> >> +				   const struct factors_data *data,
> >> +				   spinlock_t *lock,
> >> +				   void __iomem *reg);
> > 
> > Why are you dropping the __init there?
> 
> Because it is going to be used from mfd instantiation, so from a platform_dev
> probe function which is not __init.

Ah right. Mentionning it in the commit log would be nice.

> 
> > 
> >>  
> >>  #endif
> >> diff --git a/drivers/clk/sunxi/clk-mod0.c b/drivers/clk/sunxi/clk-mod0.c
> >> index 4a56385..9530833 100644
> >> --- a/drivers/clk/sunxi/clk-mod0.c
> >> +++ b/drivers/clk/sunxi/clk-mod0.c
> >> @@ -78,7 +78,8 @@ static DEFINE_SPINLOCK(sun4i_a10_mod0_lock);
> >>  
> >>  static void __init sun4i_a10_mod0_setup(struct device_node *node)
> >>  {
> >> -	sunxi_factors_register(node, &sun4i_a10_mod0_data, &sun4i_a10_mod0_lock);
> >> +	sunxi_factors_register(node, &sun4i_a10_mod0_data,
> >> +			       &sun4i_a10_mod0_lock, of_iomap(node, 0));
> > 
> > As of_iomap can fail, I'd rather check the returned value before
> > calling sunxi_factors_register.
> > 
> > I know it wasn't done before, but it's the right thing to do, as it
> > would lead to an instant crash if that fails.
> 
> Ok, I'll wait for you to review the rest of the series and then do a v2 of the
> patch-set with this fixed (as time permits).

Thanks!
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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Re: [PATCH 5/9] rc: sunxi-cir: Add support for the larger fifo found on sun5i and sun6i

[Maxime Ripard]

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On Fri, Nov 21, 2014 at 11:13:17AM +0100, Hans de Goede wrote:
> Hi,
> 
> On 11/21/2014 10:59 AM, Maxime Ripard wrote:
> > On Fri, Nov 21, 2014 at 09:42:09AM +0100, Hans de Goede wrote:
> >> Hi,
> >>
> >> On 11/21/2014 09:26 AM, Maxime Ripard wrote:
> >>> Hi Mauro,
> >>>
> >>> On Thu, Nov 20, 2014 at 02:28:56PM -0200, Mauro Carvalho Chehab wrote:
> >>>> Em Thu, 20 Nov 2014 16:55:24 +0100
> >>>> Hans de Goede <hdegoede@redhat.com> escreveu:
> >>>>
> >>>>> Add support for the larger fifo found on sun5i and sun6i, having a separate
> >>>>> compatible for the ir found on sun5i & sun6i also is useful if we ever want
> >>>>> to add ir transmit support, because the sun5i & sun6i version do not have
> >>>>> transmit support.
> >>>>>
> >>>>> Note this commits also adds checking for the end-of-packet interrupt flag
> >>>>> (which was already enabled), as the fifo-data-available interrupt flag only
> >>>>> gets set when the trigger-level is exceeded. So far we've been getting away
> >>>>> with not doing this because of the low trigger-level, but this is something
> >>>>> which we should have done since day one.
> >>>>>
> >>>>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> >>>>
> >>>> As this is meant to be merged via some other tree:
> >>>>
> >>>> Acked-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
> >>>
> >>> I think merging it through your tree would be just fine.
> >>>
> >>> Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> >>
> >> Heh, I was thinking it would be best if it went through Maxime's tree because
> >> it also has some deps on new clk stuff (well the dts have deps on that), but either
> >> way works for me.
> >>
> >> Maxime if you want this go through Mauro's tree, I can send a pull-req to Mauro
> >> (I'm a linux-media sub-maintainer), so if that is the case let me know and I'll
> >> prepare a pull-req (after fixing the missing reset documentation in the bindings).
> > 
> > So much for not reading the cover letter... Sorry.
> > 
> > We're getting quite close to the end of the ARM merge window, and I
> > got a couple comments, Lee hasn't commented yet, so I'd say it's a bit
> > too late for this to come in.
> 
> Oh, but this was not intended for 3.19, this can wait till 3.20 from my pov,
> sorry if that was not clear. I was assuming that the merge window was more
> or less closed already, so that this going into 3.20 was expected.

Perfect then :)

Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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Re: [PATCH 3/9] clk: sunxi: Add prcm mod0 clock driver

[Maxime Ripard]

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On Fri, Nov 21, 2014 at 10:13:10AM +0100, Hans de Goede wrote:
> Hi,
> 
> On 11/21/2014 09:49 AM, Maxime Ripard wrote:
> > Hi,
> > 
> > On Thu, Nov 20, 2014 at 04:55:22PM +0100, Hans de Goede wrote:
> >> Add a driver for mod0 clocks found in the prcm. Currently there is only
> >> one mod0 clocks in the prcm, the ir clock.
> >>
> >> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> >> ---
> >>  Documentation/devicetree/bindings/clock/sunxi.txt |  1 +
> >>  drivers/clk/sunxi/Makefile                        |  2 +-
> >>  drivers/clk/sunxi/clk-sun6i-prcm-mod0.c           | 63 +++++++++++++++++++++++
> >>  drivers/mfd/sun6i-prcm.c                          | 14 +++++
> >>  4 files changed, 79 insertions(+), 1 deletion(-)
> >>  create mode 100644 drivers/clk/sunxi/clk-sun6i-prcm-mod0.c
> >>
> >> diff --git a/Documentation/devicetree/bindings/clock/sunxi.txt b/Documentation/devicetree/bindings/clock/sunxi.txt
> >> index ed116df..342c75a 100644
> >> --- a/Documentation/devicetree/bindings/clock/sunxi.txt
> >> +++ b/Documentation/devicetree/bindings/clock/sunxi.txt
> >> @@ -56,6 +56,7 @@ Required properties:
> >>  	"allwinner,sun4i-a10-usb-clk" - for usb gates + resets on A10 / A20
> >>  	"allwinner,sun5i-a13-usb-clk" - for usb gates + resets on A13
> >>  	"allwinner,sun6i-a31-usb-clk" - for usb gates + resets on A31
> >> +	"allwinner,sun6i-a31-ir-clk" - for the ir clock on A31
> >>  
> >>  Required properties for all clocks:
> >>  - reg : shall be the control register address for the clock.
> >> diff --git a/drivers/clk/sunxi/Makefile b/drivers/clk/sunxi/Makefile
> >> index 7ddc2b5..daf8b1c 100644
> >> --- a/drivers/clk/sunxi/Makefile
> >> +++ b/drivers/clk/sunxi/Makefile
> >> @@ -10,4 +10,4 @@ obj-y += clk-sun8i-mbus.o
> >>  
> >>  obj-$(CONFIG_MFD_SUN6I_PRCM) += \
> >>  	clk-sun6i-ar100.o clk-sun6i-apb0.o clk-sun6i-apb0-gates.o \
> >> -	clk-sun8i-apb0.o
> >> +	clk-sun8i-apb0.o clk-sun6i-prcm-mod0.o
> >> diff --git a/drivers/clk/sunxi/clk-sun6i-prcm-mod0.c b/drivers/clk/sunxi/clk-sun6i-prcm-mod0.c
> >> new file mode 100644
> >> index 0000000..e80f18e
> >> --- /dev/null
> >> +++ b/drivers/clk/sunxi/clk-sun6i-prcm-mod0.c
> >> @@ -0,0 +1,63 @@
> >> +/*
> >> + * Allwinner A31 PRCM mod0 clock driver
> >> + *
> >> + * Copyright (C) 2014 Hans de Goede <hdegoede@redhat.com>
> >> + *
> >> + * This program is free software; you can redistribute it and/or modify
> >> + * it under the terms of the GNU General Public License as published by
> >> + * the Free Software Foundation; either version 2 of the License, or
> >> + * (at your option) any later version.
> >> + *
> >> + * This program is distributed in the hope that it will be useful,
> >> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> >> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> >> + * GNU General Public License for more details.
> >> + */
> >> +
> >> +#include <linux/clk-provider.h>
> >> +#include <linux/clkdev.h>
> >> +#include <linux/module.h>
> >> +#include <linux/of_address.h>
> >> +#include <linux/platform_device.h>
> >> +
> >> +#include "clk-factors.h"
> >> +#include "clk-mod0.h"
> >> +
> >> +static const struct of_device_id sun6i_a31_prcm_mod0_clk_dt_ids[] = {
> >> +	{ .compatible = "allwinner,sun6i-a31-ir-clk" },
> >> +	{ /* sentinel */ }
> >> +};
> >> +
> >> +static DEFINE_SPINLOCK(sun6i_prcm_mod0_lock);
> >> +
> >> +static int sun6i_a31_prcm_mod0_clk_probe(struct platform_device *pdev)
> >> +{
> >> +	struct device_node *np = pdev->dev.of_node;
> >> +	struct resource *r;
> >> +	void __iomem *reg;
> >> +
> >> +	if (!np)
> >> +		return -ENODEV;
> >> +
> >> +	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> >> +	reg = devm_ioremap_resource(&pdev->dev, r);
> >> +	if (IS_ERR(reg))
> >> +		return PTR_ERR(reg);
> >> +
> >> +	sunxi_factors_register(np, &sun4i_a10_mod0_data,
> >> +			       &sun6i_prcm_mod0_lock, reg);
> >> +	return 0;
> >> +}
> >> +
> >> +static struct platform_driver sun6i_a31_prcm_mod0_clk_driver = {
> >> +	.driver = {
> >> +		.name = "sun6i-a31-prcm-mod0-clk",
> >> +		.of_match_table = sun6i_a31_prcm_mod0_clk_dt_ids,
> >> +	},
> >> +	.probe = sun6i_a31_prcm_mod0_clk_probe,
> >> +};
> >> +module_platform_driver(sun6i_a31_prcm_mod0_clk_driver);
> >> +
> >> +MODULE_DESCRIPTION("Allwinner A31 PRCM mod0 clock driver");
> >> +MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
> >> +MODULE_LICENSE("GPL");
> > 
> > I don't think this is the right approach, mainly for two reasons: the
> > compatible shouldn't change, and you're basically duplicating code
> > there.
> > 
> > I understand that you need the new compatible in order to avoid a
> > double probing: one by CLK_OF_DECLARE, and one by the usual mechanism,
> > and that also implies the second reason.
> 
> Not only for that, we need a new compatible also because the mfd framework
> needs a separate compatible per sub-node as that is how it finds nodes
> to attach to the platform devices, so we need a new compatible anyways,
> with your make the mod0 clock driver a platform driver solution we could
> use:

We have a single mod0 clock in there, so no, not really.

Plus, that seems like a bogus limitation from MFD, and it really
shouldn't work that way.

> 	compatible = "allwinner,sun6i-a31-ir-clk", "allwinner,sun4i-a10-mod0-clk";
> 
> To work around this, but there are other problems, your make mod0clk a
> platform driver solution cannot work because the clocks node in the dtsi
> is not simple-bus compatible, so no platform-devs will be instantiated for
> the clocks there.

Then add the simple-bus compatible.

> Besides the compatible (which as said we need a separate one anyways),
> your other worry is code duplication, but I've avoided that as much
> as possible already, the new drivers/clk/sunxi/clk-sun6i-prcm-mod0.c is
> just a very thin wrapper, waying in with all of 63 lines including
> 16 lines GPL header.

47 lines that are doing exactly the same thing as the other code is
doing. I'm sorry but you can't really argue it's not code duplication,
it really is.

> So sorry, I disagree I believe that this is the best solution.
> 
> > However, as those are not critical clocks that need to be here early
> > at boot, you can also fix this by turning the mod0 driver into a
> > platform driver itself. The compatible will be kept, the driver will
> > be the same.
> > 
> > The only thing we need to pay attention to is how "client" drivers
> > react when they cannot grab their clock. They should return
> > -EPROBE_DEFER, but that remains to be checked.
> 
> -EPROBE_DEFER is yet another reason to not make mod0-clk a platform
> driver. Yes drivers should be able to handle this, but it is a pain,
> and the more we use it the more pain it is. Also it makes booting a lot
> slower as any driver using a mod0 clk now, will not complete its probe
> until all the other drivers are done probing and the late_initcall
> which starts the deferred-probe wq runs.

The whole EPROBE_DEFER mechanism might need some fixing, but it's not
really the point is it?

Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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Re: [PATCH 3/9] clk: sunxi: Add prcm mod0 clock driver

[Hans de Goede]

Hi,

On 11/24/2014 11:03 PM, Maxime Ripard wrote:
> On Fri, Nov 21, 2014 at 10:13:10AM +0100, Hans de Goede wrote:
>> Hi,
>>
>> On 11/21/2014 09:49 AM, Maxime Ripard wrote:
>>> Hi,
>>>
>>> On Thu, Nov 20, 2014 at 04:55:22PM +0100, Hans de Goede wrote:
>>>> Add a driver for mod0 clocks found in the prcm. Currently there is only
>>>> one mod0 clocks in the prcm, the ir clock.
>>>>
>>>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>>>> ---
>>>>   Documentation/devicetree/bindings/clock/sunxi.txt |  1 +
>>>>   drivers/clk/sunxi/Makefile                        |  2 +-
>>>>   drivers/clk/sunxi/clk-sun6i-prcm-mod0.c           | 63 +++++++++++++++++++++++
>>>>   drivers/mfd/sun6i-prcm.c                          | 14 +++++
>>>>   4 files changed, 79 insertions(+), 1 deletion(-)
>>>>   create mode 100644 drivers/clk/sunxi/clk-sun6i-prcm-mod0.c
>>>>
>>>> diff --git a/Documentation/devicetree/bindings/clock/sunxi.txt b/Documentation/devicetree/bindings/clock/sunxi.txt
>>>> index ed116df..342c75a 100644
>>>> --- a/Documentation/devicetree/bindings/clock/sunxi.txt
>>>> +++ b/Documentation/devicetree/bindings/clock/sunxi.txt
>>>> @@ -56,6 +56,7 @@ Required properties:
>>>>   	"allwinner,sun4i-a10-usb-clk" - for usb gates + resets on A10 / A20
>>>>   	"allwinner,sun5i-a13-usb-clk" - for usb gates + resets on A13
>>>>   	"allwinner,sun6i-a31-usb-clk" - for usb gates + resets on A31
>>>> +	"allwinner,sun6i-a31-ir-clk" - for the ir clock on A31
>>>>
>>>>   Required properties for all clocks:
>>>>   - reg : shall be the control register address for the clock.
>>>> diff --git a/drivers/clk/sunxi/Makefile b/drivers/clk/sunxi/Makefile
>>>> index 7ddc2b5..daf8b1c 100644
>>>> --- a/drivers/clk/sunxi/Makefile
>>>> +++ b/drivers/clk/sunxi/Makefile
>>>> @@ -10,4 +10,4 @@ obj-y += clk-sun8i-mbus.o
>>>>
>>>>   obj-$(CONFIG_MFD_SUN6I_PRCM) += \
>>>>   	clk-sun6i-ar100.o clk-sun6i-apb0.o clk-sun6i-apb0-gates.o \
>>>> -	clk-sun8i-apb0.o
>>>> +	clk-sun8i-apb0.o clk-sun6i-prcm-mod0.o
>>>> diff --git a/drivers/clk/sunxi/clk-sun6i-prcm-mod0.c b/drivers/clk/sunxi/clk-sun6i-prcm-mod0.c
>>>> new file mode 100644
>>>> index 0000000..e80f18e
>>>> --- /dev/null
>>>> +++ b/drivers/clk/sunxi/clk-sun6i-prcm-mod0.c
>>>> @@ -0,0 +1,63 @@
>>>> +/*
>>>> + * Allwinner A31 PRCM mod0 clock driver
>>>> + *
>>>> + * Copyright (C) 2014 Hans de Goede <hdegoede@redhat.com>
>>>> + *
>>>> + * This program is free software; you can redistribute it and/or modify
>>>> + * it under the terms of the GNU General Public License as published by
>>>> + * the Free Software Foundation; either version 2 of the License, or
>>>> + * (at your option) any later version.
>>>> + *
>>>> + * This program is distributed in the hope that it will be useful,
>>>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>>>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>>>> + * GNU General Public License for more details.
>>>> + */
>>>> +
>>>> +#include <linux/clk-provider.h>
>>>> +#include <linux/clkdev.h>
>>>> +#include <linux/module.h>
>>>> +#include <linux/of_address.h>
>>>> +#include <linux/platform_device.h>
>>>> +
>>>> +#include "clk-factors.h"
>>>> +#include "clk-mod0.h"
>>>> +
>>>> +static const struct of_device_id sun6i_a31_prcm_mod0_clk_dt_ids[] = {
>>>> +	{ .compatible = "allwinner,sun6i-a31-ir-clk" },
>>>> +	{ /* sentinel */ }
>>>> +};
>>>> +
>>>> +static DEFINE_SPINLOCK(sun6i_prcm_mod0_lock);
>>>> +
>>>> +static int sun6i_a31_prcm_mod0_clk_probe(struct platform_device *pdev)
>>>> +{
>>>> +	struct device_node *np = pdev->dev.of_node;
>>>> +	struct resource *r;
>>>> +	void __iomem *reg;
>>>> +
>>>> +	if (!np)
>>>> +		return -ENODEV;
>>>> +
>>>> +	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>>>> +	reg = devm_ioremap_resource(&pdev->dev, r);
>>>> +	if (IS_ERR(reg))
>>>> +		return PTR_ERR(reg);
>>>> +
>>>> +	sunxi_factors_register(np, &sun4i_a10_mod0_data,
>>>> +			       &sun6i_prcm_mod0_lock, reg);
>>>> +	return 0;
>>>> +}
>>>> +
>>>> +static struct platform_driver sun6i_a31_prcm_mod0_clk_driver = {
>>>> +	.driver = {
>>>> +		.name = "sun6i-a31-prcm-mod0-clk",
>>>> +		.of_match_table = sun6i_a31_prcm_mod0_clk_dt_ids,
>>>> +	},
>>>> +	.probe = sun6i_a31_prcm_mod0_clk_probe,
>>>> +};
>>>> +module_platform_driver(sun6i_a31_prcm_mod0_clk_driver);
>>>> +
>>>> +MODULE_DESCRIPTION("Allwinner A31 PRCM mod0 clock driver");
>>>> +MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
>>>> +MODULE_LICENSE("GPL");
>>>
>>> I don't think this is the right approach, mainly for two reasons: the
>>> compatible shouldn't change, and you're basically duplicating code
>>> there.
>>>
>>> I understand that you need the new compatible in order to avoid a
>>> double probing: one by CLK_OF_DECLARE, and one by the usual mechanism,
>>> and that also implies the second reason.
>>
>> Not only for that, we need a new compatible also because the mfd framework
>> needs a separate compatible per sub-node as that is how it finds nodes
>> to attach to the platform devices, so we need a new compatible anyways,
>> with your make the mod0 clock driver a platform driver solution we could
>> use:
>
> We have a single mod0 clock in there, so no, not really.

We have a single mod0 clock there today, but who knows what tomorrow brings,
arguably the 1wire clock is a mod0 clock too, so we already have 2 today.

> Plus, that seems like a bogus limitation from MFD, and it really
> shouldn't work that way.

Well AFAIK that is how it works.

>> 	compatible = "allwinner,sun6i-a31-ir-clk", "allwinner,sun4i-a10-mod0-clk";
>>
>> To work around this, but there are other problems, your make mod0clk a
>> platform driver solution cannot work because the clocks node in the dtsi
>> is not simple-bus compatible, so no platform-devs will be instantiated for
>> the clocks there.
>
> Then add the simple-bus compatible.

No, just no, that goes against the whole design of how of-clocks work.

>> Besides the compatible (which as said we need a separate one anyways),
>> your other worry is code duplication, but I've avoided that as much
>> as possible already, the new drivers/clk/sunxi/clk-sun6i-prcm-mod0.c is
>> just a very thin wrapper, waying in with all of 63 lines including
>> 16 lines GPL header.
>
> 47 lines that are doing exactly the same thing as the other code is
> doing. I'm sorry but you can't really argue it's not code duplication,
> it really is.

It is not doing the exact same thing, it is a platform driver, where as
the other code is an of_clk driver.

>> So sorry, I disagree I believe that this is the best solution.
>>
>>> However, as those are not critical clocks that need to be here early
>>> at boot, you can also fix this by turning the mod0 driver into a
>>> platform driver itself. The compatible will be kept, the driver will
>>> be the same.
>>>
>>> The only thing we need to pay attention to is how "client" drivers
>>> react when they cannot grab their clock. They should return
>>> -EPROBE_DEFER, but that remains to be checked.
>>
>> -EPROBE_DEFER is yet another reason to not make mod0-clk a platform
>> driver. Yes drivers should be able to handle this, but it is a pain,
>> and the more we use it the more pain it is. Also it makes booting a lot
>> slower as any driver using a mod0 clk now, will not complete its probe
>> until all the other drivers are done probing and the late_initcall
>> which starts the deferred-probe wq runs.
>
> The whole EPROBE_DEFER mechanism might need some fixing, but it's not
> really the point is it?

Well one reasons why clocks are instantiated the way they are is to have
them available as early as possible, which is really convenient and works
really well.

You are asking for a whole lot of stuff to be changed, arguably in a way
which makes it worse, just to save 47 lines of code...

Regards,

Hans

Re: [PATCH 3/9] clk: sunxi: Add prcm mod0 clock driver

[Hans de Goede]

Hi,

On 11/25/2014 09:29 AM, Hans de Goede wrote:

<snip>

> Well one reasons why clocks are instantiated the way they are is to have
> them available as early as possible, which is really convenient and works
> really well.
>
> You are asking for a whole lot of stuff to be changed, arguably in a way
> which makes it worse, just to save 47 lines of code...

Thinking more about this one alternative which should work is to just put the
clocks in the prcm in the clocks node, then they get their own reg property,
rather then being part of the prcm reg range, and the standard of_clk mod0
driver we have will just work.

Regards,

Hans

Re: [PATCH 3/9] clk: sunxi: Add prcm mod0 clock driver

[Maxime Ripard]

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Hi,

On Tue, Nov 25, 2014 at 09:29:21AM +0100, Hans de Goede wrote:
> Hi,
> 
> On 11/24/2014 11:03 PM, Maxime Ripard wrote:
> >On Fri, Nov 21, 2014 at 10:13:10AM +0100, Hans de Goede wrote:
> >>Hi,
> >>
> >>On 11/21/2014 09:49 AM, Maxime Ripard wrote:
> >>>Hi,
> >>>
> >>>On Thu, Nov 20, 2014 at 04:55:22PM +0100, Hans de Goede wrote:
> >>>>Add a driver for mod0 clocks found in the prcm. Currently there is only
> >>>>one mod0 clocks in the prcm, the ir clock.
> >>>>
> >>>>Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> >>>>---
> >>>>  Documentation/devicetree/bindings/clock/sunxi.txt |  1 +
> >>>>  drivers/clk/sunxi/Makefile                        |  2 +-
> >>>>  drivers/clk/sunxi/clk-sun6i-prcm-mod0.c           | 63 +++++++++++++++++++++++
> >>>>  drivers/mfd/sun6i-prcm.c                          | 14 +++++
> >>>>  4 files changed, 79 insertions(+), 1 deletion(-)
> >>>>  create mode 100644 drivers/clk/sunxi/clk-sun6i-prcm-mod0.c
> >>>>
> >>>>diff --git a/Documentation/devicetree/bindings/clock/sunxi.txt b/Documentation/devicetree/bindings/clock/sunxi.txt
> >>>>index ed116df..342c75a 100644
> >>>>--- a/Documentation/devicetree/bindings/clock/sunxi.txt
> >>>>+++ b/Documentation/devicetree/bindings/clock/sunxi.txt
> >>>>@@ -56,6 +56,7 @@ Required properties:
> >>>>  	"allwinner,sun4i-a10-usb-clk" - for usb gates + resets on A10 / A20
> >>>>  	"allwinner,sun5i-a13-usb-clk" - for usb gates + resets on A13
> >>>>  	"allwinner,sun6i-a31-usb-clk" - for usb gates + resets on A31
> >>>>+	"allwinner,sun6i-a31-ir-clk" - for the ir clock on A31
> >>>>
> >>>>  Required properties for all clocks:
> >>>>  - reg : shall be the control register address for the clock.
> >>>>diff --git a/drivers/clk/sunxi/Makefile b/drivers/clk/sunxi/Makefile
> >>>>index 7ddc2b5..daf8b1c 100644
> >>>>--- a/drivers/clk/sunxi/Makefile
> >>>>+++ b/drivers/clk/sunxi/Makefile
> >>>>@@ -10,4 +10,4 @@ obj-y += clk-sun8i-mbus.o
> >>>>
> >>>>  obj-$(CONFIG_MFD_SUN6I_PRCM) += \
> >>>>  	clk-sun6i-ar100.o clk-sun6i-apb0.o clk-sun6i-apb0-gates.o \
> >>>>-	clk-sun8i-apb0.o
> >>>>+	clk-sun8i-apb0.o clk-sun6i-prcm-mod0.o
> >>>>diff --git a/drivers/clk/sunxi/clk-sun6i-prcm-mod0.c b/drivers/clk/sunxi/clk-sun6i-prcm-mod0.c
> >>>>new file mode 100644
> >>>>index 0000000..e80f18e
> >>>>--- /dev/null
> >>>>+++ b/drivers/clk/sunxi/clk-sun6i-prcm-mod0.c
> >>>>@@ -0,0 +1,63 @@
> >>>>+/*
> >>>>+ * Allwinner A31 PRCM mod0 clock driver
> >>>>+ *
> >>>>+ * Copyright (C) 2014 Hans de Goede <hdegoede@redhat.com>
> >>>>+ *
> >>>>+ * This program is free software; you can redistribute it and/or modify
> >>>>+ * it under the terms of the GNU General Public License as published by
> >>>>+ * the Free Software Foundation; either version 2 of the License, or
> >>>>+ * (at your option) any later version.
> >>>>+ *
> >>>>+ * This program is distributed in the hope that it will be useful,
> >>>>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
> >>>>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> >>>>+ * GNU General Public License for more details.
> >>>>+ */
> >>>>+
> >>>>+#include <linux/clk-provider.h>
> >>>>+#include <linux/clkdev.h>
> >>>>+#include <linux/module.h>
> >>>>+#include <linux/of_address.h>
> >>>>+#include <linux/platform_device.h>
> >>>>+
> >>>>+#include "clk-factors.h"
> >>>>+#include "clk-mod0.h"
> >>>>+
> >>>>+static const struct of_device_id sun6i_a31_prcm_mod0_clk_dt_ids[] = {
> >>>>+	{ .compatible = "allwinner,sun6i-a31-ir-clk" },
> >>>>+	{ /* sentinel */ }
> >>>>+};
> >>>>+
> >>>>+static DEFINE_SPINLOCK(sun6i_prcm_mod0_lock);
> >>>>+
> >>>>+static int sun6i_a31_prcm_mod0_clk_probe(struct platform_device *pdev)
> >>>>+{
> >>>>+	struct device_node *np = pdev->dev.of_node;
> >>>>+	struct resource *r;
> >>>>+	void __iomem *reg;
> >>>>+
> >>>>+	if (!np)
> >>>>+		return -ENODEV;
> >>>>+
> >>>>+	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> >>>>+	reg = devm_ioremap_resource(&pdev->dev, r);
> >>>>+	if (IS_ERR(reg))
> >>>>+		return PTR_ERR(reg);
> >>>>+
> >>>>+	sunxi_factors_register(np, &sun4i_a10_mod0_data,
> >>>>+			       &sun6i_prcm_mod0_lock, reg);
> >>>>+	return 0;
> >>>>+}
> >>>>+
> >>>>+static struct platform_driver sun6i_a31_prcm_mod0_clk_driver = {
> >>>>+	.driver = {
> >>>>+		.name = "sun6i-a31-prcm-mod0-clk",
> >>>>+		.of_match_table = sun6i_a31_prcm_mod0_clk_dt_ids,
> >>>>+	},
> >>>>+	.probe = sun6i_a31_prcm_mod0_clk_probe,
> >>>>+};
> >>>>+module_platform_driver(sun6i_a31_prcm_mod0_clk_driver);
> >>>>+
> >>>>+MODULE_DESCRIPTION("Allwinner A31 PRCM mod0 clock driver");
> >>>>+MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
> >>>>+MODULE_LICENSE("GPL");
> >>>
> >>>I don't think this is the right approach, mainly for two reasons: the
> >>>compatible shouldn't change, and you're basically duplicating code
> >>>there.
> >>>
> >>>I understand that you need the new compatible in order to avoid a
> >>>double probing: one by CLK_OF_DECLARE, and one by the usual mechanism,
> >>>and that also implies the second reason.
> >>
> >>Not only for that, we need a new compatible also because the mfd framework
> >>needs a separate compatible per sub-node as that is how it finds nodes
> >>to attach to the platform devices, so we need a new compatible anyways,
> >>with your make the mod0 clock driver a platform driver solution we could
> >>use:
> >
> >We have a single mod0 clock in there, so no, not really.
> 
> We have a single mod0 clock there today, but who knows what tomorrow brings,
> arguably the 1wire clock is a mod0 clock too, so we already have 2 today.

I remember someone (Chen-Yu? Boris?) saying that the 1wire clock was
not really a mod0 clk. From what I could gather from the source code,
it seems to have a wider m divider, so we could argue that it should
need a new compatible.

> >Plus, that seems like a bogus limitation from MFD, and it really
> >shouldn't work that way.
> 
> Well AFAIK that is how it works.

That kind of argument doesn't work. You could make exactly the same
statement about the fact that two identical hardware blocks in the DT
should have the same compatible, and it's how it works.

With the minor exception that we can't change that fact for the DT,
while we can change the MTD code.

> >>	compatible = "allwinner,sun6i-a31-ir-clk", "allwinner,sun4i-a10-mod0-clk";
> >>
> >>To work around this, but there are other problems, your make mod0clk a
> >>platform driver solution cannot work because the clocks node in the dtsi
> >>is not simple-bus compatible, so no platform-devs will be instantiated for
> >>the clocks there.
> >
> >Then add the simple-bus compatible.
> 
> No, just no, that goes against the whole design of how of-clocks work.

Which is... ?

There's a number of other clocks being platform drivers, including on
other platforms, and as far as I know, CLK_OF_DECLARE is only really
useful on clocks that are critical. Mike, what's your view on this?

> >>Besides the compatible (which as said we need a separate one anyways),
> >>your other worry is code duplication, but I've avoided that as much
> >>as possible already, the new drivers/clk/sunxi/clk-sun6i-prcm-mod0.c is
> >>just a very thin wrapper, waying in with all of 63 lines including
> >>16 lines GPL header.
> >
> >47 lines that are doing exactly the same thing as the other code is
> >doing. I'm sorry but you can't really argue it's not code duplication,
> >it really is.
> 
> It is not doing the exact same thing, it is a platform driver, where as
> the other code is an of_clk driver.
> 
> >>So sorry, I disagree I believe that this is the best solution.
> >>
> >>>However, as those are not critical clocks that need to be here early
> >>>at boot, you can also fix this by turning the mod0 driver into a
> >>>platform driver itself. The compatible will be kept, the driver will
> >>>be the same.
> >>>
> >>>The only thing we need to pay attention to is how "client" drivers
> >>>react when they cannot grab their clock. They should return
> >>>-EPROBE_DEFER, but that remains to be checked.
> >>
> >>-EPROBE_DEFER is yet another reason to not make mod0-clk a platform
> >>driver. Yes drivers should be able to handle this, but it is a pain,
> >>and the more we use it the more pain it is. Also it makes booting a lot
> >>slower as any driver using a mod0 clk now, will not complete its probe
> >>until all the other drivers are done probing and the late_initcall
> >>which starts the deferred-probe wq runs.
> >
> >The whole EPROBE_DEFER mechanism might need some fixing, but it's not
> >really the point is it?
> 
> Well one reasons why clocks are instantiated the way they are is to have
> them available as early as possible, which is really convenient and works
> really well.

Yeah, you need them early for critical and early stuff like timers,
console, etc. You really don't need this mechanism if you don't have
to handle early probed devices.

> You are asking for a whole lot of stuff to be changed, arguably in a way
> which makes it worse, just to save 47 lines of code...

No, really, I'm not. All I ask for is adding 1 line in the DT, and
removing 5 lines in clk-sunxi.c. That's all.

You're the one being unhappy with EPROBE_DEFER, not me.

Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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Re: [PATCH 3/9] clk: sunxi: Add prcm mod0 clock driver

[Hans de Goede]

Hi,

On 11/26/2014 10:13 PM, Maxime Ripard wrote:
> Hi,
>
> On Tue, Nov 25, 2014 at 09:29:21AM +0100, Hans de Goede wrote:
>> Hi,
>>
>> On 11/24/2014 11:03 PM, Maxime Ripard wrote:
>>> On Fri, Nov 21, 2014 at 10:13:10AM +0100, Hans de Goede wrote:
>>>> Hi,
>>>>
>>>> On 11/21/2014 09:49 AM, Maxime Ripard wrote:
>>>>> Hi,
>>>>>
>>>>> On Thu, Nov 20, 2014 at 04:55:22PM +0100, Hans de Goede wrote:
>>>>>> Add a driver for mod0 clocks found in the prcm. Currently there is only
>>>>>> one mod0 clocks in the prcm, the ir clock.
>>>>>>
>>>>>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>>>>>> ---
>>>>>>   Documentation/devicetree/bindings/clock/sunxi.txt |  1 +
>>>>>>   drivers/clk/sunxi/Makefile                        |  2 +-
>>>>>>   drivers/clk/sunxi/clk-sun6i-prcm-mod0.c           | 63 +++++++++++++++++++++++
>>>>>>   drivers/mfd/sun6i-prcm.c                          | 14 +++++
>>>>>>   4 files changed, 79 insertions(+), 1 deletion(-)
>>>>>>   create mode 100644 drivers/clk/sunxi/clk-sun6i-prcm-mod0.c
>>>>>>
>>>>>> diff --git a/Documentation/devicetree/bindings/clock/sunxi.txt b/Documentation/devicetree/bindings/clock/sunxi.txt
>>>>>> index ed116df..342c75a 100644
>>>>>> --- a/Documentation/devicetree/bindings/clock/sunxi.txt
>>>>>> +++ b/Documentation/devicetree/bindings/clock/sunxi.txt
>>>>>> @@ -56,6 +56,7 @@ Required properties:
>>>>>>   	"allwinner,sun4i-a10-usb-clk" - for usb gates + resets on A10 / A20
>>>>>>   	"allwinner,sun5i-a13-usb-clk" - for usb gates + resets on A13
>>>>>>   	"allwinner,sun6i-a31-usb-clk" - for usb gates + resets on A31
>>>>>> +	"allwinner,sun6i-a31-ir-clk" - for the ir clock on A31
>>>>>>
>>>>>>   Required properties for all clocks:
>>>>>>   - reg : shall be the control register address for the clock.
>>>>>> diff --git a/drivers/clk/sunxi/Makefile b/drivers/clk/sunxi/Makefile
>>>>>> index 7ddc2b5..daf8b1c 100644
>>>>>> --- a/drivers/clk/sunxi/Makefile
>>>>>> +++ b/drivers/clk/sunxi/Makefile
>>>>>> @@ -10,4 +10,4 @@ obj-y += clk-sun8i-mbus.o
>>>>>>
>>>>>>   obj-$(CONFIG_MFD_SUN6I_PRCM) += \
>>>>>>   	clk-sun6i-ar100.o clk-sun6i-apb0.o clk-sun6i-apb0-gates.o \
>>>>>> -	clk-sun8i-apb0.o
>>>>>> +	clk-sun8i-apb0.o clk-sun6i-prcm-mod0.o
>>>>>> diff --git a/drivers/clk/sunxi/clk-sun6i-prcm-mod0.c b/drivers/clk/sunxi/clk-sun6i-prcm-mod0.c
>>>>>> new file mode 100644
>>>>>> index 0000000..e80f18e
>>>>>> --- /dev/null
>>>>>> +++ b/drivers/clk/sunxi/clk-sun6i-prcm-mod0.c
>>>>>> @@ -0,0 +1,63 @@
>>>>>> +/*
>>>>>> + * Allwinner A31 PRCM mod0 clock driver
>>>>>> + *
>>>>>> + * Copyright (C) 2014 Hans de Goede <hdegoede@redhat.com>
>>>>>> + *
>>>>>> + * This program is free software; you can redistribute it and/or modify
>>>>>> + * it under the terms of the GNU General Public License as published by
>>>>>> + * the Free Software Foundation; either version 2 of the License, or
>>>>>> + * (at your option) any later version.
>>>>>> + *
>>>>>> + * This program is distributed in the hope that it will be useful,
>>>>>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>>>>>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>>>>>> + * GNU General Public License for more details.
>>>>>> + */
>>>>>> +
>>>>>> +#include <linux/clk-provider.h>
>>>>>> +#include <linux/clkdev.h>
>>>>>> +#include <linux/module.h>
>>>>>> +#include <linux/of_address.h>
>>>>>> +#include <linux/platform_device.h>
>>>>>> +
>>>>>> +#include "clk-factors.h"
>>>>>> +#include "clk-mod0.h"
>>>>>> +
>>>>>> +static const struct of_device_id sun6i_a31_prcm_mod0_clk_dt_ids[] = {
>>>>>> +	{ .compatible = "allwinner,sun6i-a31-ir-clk" },
>>>>>> +	{ /* sentinel */ }
>>>>>> +};
>>>>>> +
>>>>>> +static DEFINE_SPINLOCK(sun6i_prcm_mod0_lock);
>>>>>> +
>>>>>> +static int sun6i_a31_prcm_mod0_clk_probe(struct platform_device *pdev)
>>>>>> +{
>>>>>> +	struct device_node *np = pdev->dev.of_node;
>>>>>> +	struct resource *r;
>>>>>> +	void __iomem *reg;
>>>>>> +
>>>>>> +	if (!np)
>>>>>> +		return -ENODEV;
>>>>>> +
>>>>>> +	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>>>>>> +	reg = devm_ioremap_resource(&pdev->dev, r);
>>>>>> +	if (IS_ERR(reg))
>>>>>> +		return PTR_ERR(reg);
>>>>>> +
>>>>>> +	sunxi_factors_register(np, &sun4i_a10_mod0_data,
>>>>>> +			       &sun6i_prcm_mod0_lock, reg);
>>>>>> +	return 0;
>>>>>> +}
>>>>>> +
>>>>>> +static struct platform_driver sun6i_a31_prcm_mod0_clk_driver = {
>>>>>> +	.driver = {
>>>>>> +		.name = "sun6i-a31-prcm-mod0-clk",
>>>>>> +		.of_match_table = sun6i_a31_prcm_mod0_clk_dt_ids,
>>>>>> +	},
>>>>>> +	.probe = sun6i_a31_prcm_mod0_clk_probe,
>>>>>> +};
>>>>>> +module_platform_driver(sun6i_a31_prcm_mod0_clk_driver);
>>>>>> +
>>>>>> +MODULE_DESCRIPTION("Allwinner A31 PRCM mod0 clock driver");
>>>>>> +MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
>>>>>> +MODULE_LICENSE("GPL");
>>>>>
>>>>> I don't think this is the right approach, mainly for two reasons: the
>>>>> compatible shouldn't change, and you're basically duplicating code
>>>>> there.
>>>>>
>>>>> I understand that you need the new compatible in order to avoid a
>>>>> double probing: one by CLK_OF_DECLARE, and one by the usual mechanism,
>>>>> and that also implies the second reason.
>>>>
>>>> Not only for that, we need a new compatible also because the mfd framework
>>>> needs a separate compatible per sub-node as that is how it finds nodes
>>>> to attach to the platform devices, so we need a new compatible anyways,
>>>> with your make the mod0 clock driver a platform driver solution we could
>>>> use:
>>>
>>> We have a single mod0 clock in there, so no, not really.
>>
>> We have a single mod0 clock there today, but who knows what tomorrow brings,
>> arguably the 1wire clock is a mod0 clock too, so we already have 2 today.
>
> I remember someone (Chen-Yu? Boris?) saying that the 1wire clock was
> not really a mod0 clk. From what I could gather from the source code,
> it seems to have a wider m divider, so we could argue that it should
> need a new compatible.
>
>>> Plus, that seems like a bogus limitation from MFD, and it really
>>> shouldn't work that way.
>>
>> Well AFAIK that is how it works.
>
> That kind of argument doesn't work. You could make exactly the same
> statement about the fact that two identical hardware blocks in the DT
> should have the same compatible, and it's how it works.
>
> With the minor exception that we can't change that fact for the DT,
> while we can change the MTD code.

As I already said, we could do something like this to make clear this
is a mod0 clock:

>>>> 	compatible = "allwinner,sun6i-a31-ir-clk", "allwinner,sun4i-a10-mod0-clk";

The problem with that is it will cause early binding because of
CLK_OF_DECLARE and early binding does not work on MFD instantiated devices,
because they have no reg property.



>>>>
>>>> To work around this, but there are other problems, your make mod0clk a
>>>> platform driver solution cannot work because the clocks node in the dtsi
>>>> is not simple-bus compatible, so no platform-devs will be instantiated for
>>>> the clocks there.
>>>
>>> Then add the simple-bus compatible.
>>
>> No, just no, that goes against the whole design of how of-clocks work.
>
> Which is... ?

That they are child nodes of a clocks node, which is NOT simple-bus compatible
and get instantiated early using CLK_OF_DECLARE.

> There's a number of other clocks being platform drivers, including on
> other platforms, and as far as I know, CLK_OF_DECLARE is only really
> useful on clocks that are critical. Mike, what's your view on this?
>
>>>> Besides the compatible (which as said we need a separate one anyways),
>>>> your other worry is code duplication, but I've avoided that as much
>>>> as possible already, the new drivers/clk/sunxi/clk-sun6i-prcm-mod0.c is
>>>> just a very thin wrapper, waying in with all of 63 lines including
>>>> 16 lines GPL header.
>>>
>>> 47 lines that are doing exactly the same thing as the other code is
>>> doing. I'm sorry but you can't really argue it's not code duplication,
>>> it really is.
>>
>> It is not doing the exact same thing, it is a platform driver, where as
>> the other code is an of_clk driver.
>>
>>>> So sorry, I disagree I believe that this is the best solution.
>>>>
>>>>> However, as those are not critical clocks that need to be here early
>>>>> at boot, you can also fix this by turning the mod0 driver into a
>>>>> platform driver itself. The compatible will be kept, the driver will
>>>>> be the same.
>>>>>
>>>>> The only thing we need to pay attention to is how "client" drivers
>>>>> react when they cannot grab their clock. They should return
>>>>> -EPROBE_DEFER, but that remains to be checked.
>>>>
>>>> -EPROBE_DEFER is yet another reason to not make mod0-clk a platform
>>>> driver. Yes drivers should be able to handle this, but it is a pain,
>>>> and the more we use it the more pain it is. Also it makes booting a lot
>>>> slower as any driver using a mod0 clk now, will not complete its probe
>>>> until all the other drivers are done probing and the late_initcall
>>>> which starts the deferred-probe wq runs.
>>>
>>> The whole EPROBE_DEFER mechanism might need some fixing, but it's not
>>> really the point is it?
>>
>> Well one reasons why clocks are instantiated the way they are is to have
>> them available as early as possible, which is really convenient and works
>> really well.
>
> Yeah, you need them early for critical and early stuff like timers,
> console, etc. You really don't need this mechanism if you don't have
> to handle early probed devices.

And we do need some clocks for that, if we add the simple bus compatible then
*all* of them become platform devices.

Or are you suggesting to still bind all the other clocks using CLK_OF_DECLARE
and only turn mod0 into a platform driver, that would be rather inconsistent.

>> You are asking for a whole lot of stuff to be changed, arguably in a way
>> which makes it worse, just to save 47 lines of code...
>
> No, really, I'm not. All I ask for is adding 1 line in the DT, and
> removing 5 lines in clk-sunxi.c. That's all.

And adding platform driver glue for the mod0 clks, which would pretty much
introduce the same 47 lines in a different place.

I notice that you've not responded to my proposal to simple make the clock
node a child node of the clocks node in the dt, that should work nicely, and
avoid the need for any kernel level changes to support it, I'm beginning to
think that that is probably the best solution.

Regards,

Hans

Re: [PATCH 3/9] clk: sunxi: Add prcm mod0 clock driver

[Chen-Yu Tsai]

Hi,

On Thu, Nov 27, 2014 at 4:41 PM, Hans de Goede <hdegoede@redhat.com> wrote:
> Hi,
>
>
> On 11/26/2014 10:13 PM, Maxime Ripard wrote:
>>
>> Hi,
>>
>> On Tue, Nov 25, 2014 at 09:29:21AM +0100, Hans de Goede wrote:
>>>
>>> Hi,
>>>
>>> On 11/24/2014 11:03 PM, Maxime Ripard wrote:
>>>>
>>>> On Fri, Nov 21, 2014 at 10:13:10AM +0100, Hans de Goede wrote:
>>>>>
>>>>> Hi,
>>>>>
>>>>> On 11/21/2014 09:49 AM, Maxime Ripard wrote:
>>>>>>
>>>>>> Hi,
>>>>>>
>>>>>> On Thu, Nov 20, 2014 at 04:55:22PM +0100, Hans de Goede wrote:
>>>>>>>
>>>>>>> Add a driver for mod0 clocks found in the prcm. Currently there is
>>>>>>> only
>>>>>>> one mod0 clocks in the prcm, the ir clock.
>>>>>>>
>>>>>>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>>>>>>> ---
>>>>>>>   Documentation/devicetree/bindings/clock/sunxi.txt |  1 +
>>>>>>>   drivers/clk/sunxi/Makefile                        |  2 +-
>>>>>>>   drivers/clk/sunxi/clk-sun6i-prcm-mod0.c           | 63
>>>>>>> +++++++++++++++++++++++
>>>>>>>   drivers/mfd/sun6i-prcm.c                          | 14 +++++
>>>>>>>   4 files changed, 79 insertions(+), 1 deletion(-)
>>>>>>>   create mode 100644 drivers/clk/sunxi/clk-sun6i-prcm-mod0.c
>>>>>>>
>>>>>>> diff --git a/Documentation/devicetree/bindings/clock/sunxi.txt
>>>>>>> b/Documentation/devicetree/bindings/clock/sunxi.txt
>>>>>>> index ed116df..342c75a 100644
>>>>>>> --- a/Documentation/devicetree/bindings/clock/sunxi.txt
>>>>>>> +++ b/Documentation/devicetree/bindings/clock/sunxi.txt
>>>>>>> @@ -56,6 +56,7 @@ Required properties:
>>>>>>>         "allwinner,sun4i-a10-usb-clk" - for usb gates + resets on A10
>>>>>>> / A20
>>>>>>>         "allwinner,sun5i-a13-usb-clk" - for usb gates + resets on A13
>>>>>>>         "allwinner,sun6i-a31-usb-clk" - for usb gates + resets on A31
>>>>>>> +       "allwinner,sun6i-a31-ir-clk" - for the ir clock on A31
>>>>>>>
>>>>>>>   Required properties for all clocks:
>>>>>>>   - reg : shall be the control register address for the clock.
>>>>>>> diff --git a/drivers/clk/sunxi/Makefile b/drivers/clk/sunxi/Makefile
>>>>>>> index 7ddc2b5..daf8b1c 100644
>>>>>>> --- a/drivers/clk/sunxi/Makefile
>>>>>>> +++ b/drivers/clk/sunxi/Makefile
>>>>>>> @@ -10,4 +10,4 @@ obj-y += clk-sun8i-mbus.o
>>>>>>>
>>>>>>>   obj-$(CONFIG_MFD_SUN6I_PRCM) += \
>>>>>>>         clk-sun6i-ar100.o clk-sun6i-apb0.o clk-sun6i-apb0-gates.o \
>>>>>>> -       clk-sun8i-apb0.o
>>>>>>> +       clk-sun8i-apb0.o clk-sun6i-prcm-mod0.o
>>>>>>> diff --git a/drivers/clk/sunxi/clk-sun6i-prcm-mod0.c
>>>>>>> b/drivers/clk/sunxi/clk-sun6i-prcm-mod0.c
>>>>>>> new file mode 100644
>>>>>>> index 0000000..e80f18e
>>>>>>> --- /dev/null
>>>>>>> +++ b/drivers/clk/sunxi/clk-sun6i-prcm-mod0.c
>>>>>>> @@ -0,0 +1,63 @@
>>>>>>> +/*
>>>>>>> + * Allwinner A31 PRCM mod0 clock driver
>>>>>>> + *
>>>>>>> + * Copyright (C) 2014 Hans de Goede <hdegoede@redhat.com>
>>>>>>> + *
>>>>>>> + * This program is free software; you can redistribute it and/or
>>>>>>> modify
>>>>>>> + * it under the terms of the GNU General Public License as published
>>>>>>> by
>>>>>>> + * the Free Software Foundation; either version 2 of the License, or
>>>>>>> + * (at your option) any later version.
>>>>>>> + *
>>>>>>> + * This program is distributed in the hope that it will be useful,
>>>>>>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>>>>>>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>>>>>>> + * GNU General Public License for more details.
>>>>>>> + */
>>>>>>> +
>>>>>>> +#include <linux/clk-provider.h>
>>>>>>> +#include <linux/clkdev.h>
>>>>>>> +#include <linux/module.h>
>>>>>>> +#include <linux/of_address.h>
>>>>>>> +#include <linux/platform_device.h>
>>>>>>> +
>>>>>>> +#include "clk-factors.h"
>>>>>>> +#include "clk-mod0.h"
>>>>>>> +
>>>>>>> +static const struct of_device_id sun6i_a31_prcm_mod0_clk_dt_ids[] =
>>>>>>> {
>>>>>>> +       { .compatible = "allwinner,sun6i-a31-ir-clk" },
>>>>>>> +       { /* sentinel */ }
>>>>>>> +};
>>>>>>> +
>>>>>>> +static DEFINE_SPINLOCK(sun6i_prcm_mod0_lock);
>>>>>>> +
>>>>>>> +static int sun6i_a31_prcm_mod0_clk_probe(struct platform_device
>>>>>>> *pdev)
>>>>>>> +{
>>>>>>> +       struct device_node *np = pdev->dev.of_node;
>>>>>>> +       struct resource *r;
>>>>>>> +       void __iomem *reg;
>>>>>>> +
>>>>>>> +       if (!np)
>>>>>>> +               return -ENODEV;
>>>>>>> +
>>>>>>> +       r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>>>>>>> +       reg = devm_ioremap_resource(&pdev->dev, r);
>>>>>>> +       if (IS_ERR(reg))
>>>>>>> +               return PTR_ERR(reg);
>>>>>>> +
>>>>>>> +       sunxi_factors_register(np, &sun4i_a10_mod0_data,
>>>>>>> +                              &sun6i_prcm_mod0_lock, reg);
>>>>>>> +       return 0;
>>>>>>> +}
>>>>>>> +
>>>>>>> +static struct platform_driver sun6i_a31_prcm_mod0_clk_driver = {
>>>>>>> +       .driver = {
>>>>>>> +               .name = "sun6i-a31-prcm-mod0-clk",
>>>>>>> +               .of_match_table = sun6i_a31_prcm_mod0_clk_dt_ids,
>>>>>>> +       },
>>>>>>> +       .probe = sun6i_a31_prcm_mod0_clk_probe,
>>>>>>> +};
>>>>>>> +module_platform_driver(sun6i_a31_prcm_mod0_clk_driver);
>>>>>>> +
>>>>>>> +MODULE_DESCRIPTION("Allwinner A31 PRCM mod0 clock driver");
>>>>>>> +MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
>>>>>>> +MODULE_LICENSE("GPL");
>>>>>>
>>>>>>
>>>>>> I don't think this is the right approach, mainly for two reasons: the
>>>>>> compatible shouldn't change, and you're basically duplicating code
>>>>>> there.
>>>>>>
>>>>>> I understand that you need the new compatible in order to avoid a
>>>>>> double probing: one by CLK_OF_DECLARE, and one by the usual mechanism,
>>>>>> and that also implies the second reason.
>>>>>
>>>>>
>>>>> Not only for that, we need a new compatible also because the mfd
>>>>> framework
>>>>> needs a separate compatible per sub-node as that is how it finds nodes
>>>>> to attach to the platform devices, so we need a new compatible anyways,
>>>>> with your make the mod0 clock driver a platform driver solution we
>>>>> could
>>>>> use:
>>>>
>>>>
>>>> We have a single mod0 clock in there, so no, not really.
>>>
>>>
>>> We have a single mod0 clock there today, but who knows what tomorrow
>>> brings,
>>> arguably the 1wire clock is a mod0 clock too, so we already have 2 today.
>>
>>
>> I remember someone (Chen-Yu? Boris?) saying that the 1wire clock was
>> not really a mod0 clk. From what I could gather from the source code,
>> it seems to have a wider m divider, so we could argue that it should
>> need a new compatible.
>>
>>>> Plus, that seems like a bogus limitation from MFD, and it really
>>>> shouldn't work that way.
>>>
>>>
>>> Well AFAIK that is how it works.
>>
>>
>> That kind of argument doesn't work. You could make exactly the same
>> statement about the fact that two identical hardware blocks in the DT
>> should have the same compatible, and it's how it works.
>>
>> With the minor exception that we can't change that fact for the DT,
>> while we can change the MTD code.
>
>
> As I already said, we could do something like this to make clear this
> is a mod0 clock:
>
>>>>>         compatible = "allwinner,sun6i-a31-ir-clk",
>>>>> "allwinner,sun4i-a10-mod0-clk";
>
>
> The problem with that is it will cause early binding because of
> CLK_OF_DECLARE and early binding does not work on MFD instantiated devices,
> because they have no reg property.
>
>
>
>>>>>
>>>>> To work around this, but there are other problems, your make mod0clk a
>>>>> platform driver solution cannot work because the clocks node in the
>>>>> dtsi
>>>>> is not simple-bus compatible, so no platform-devs will be instantiated
>>>>> for
>>>>> the clocks there.
>>>>
>>>>
>>>> Then add the simple-bus compatible.
>>>
>>>
>>> No, just no, that goes against the whole design of how of-clocks work.
>>
>>
>> Which is... ?
>
>
> That they are child nodes of a clocks node, which is NOT simple-bus
> compatible
> and get instantiated early using CLK_OF_DECLARE.
>
>
>> There's a number of other clocks being platform drivers, including on
>> other platforms, and as far as I know, CLK_OF_DECLARE is only really
>> useful on clocks that are critical. Mike, what's your view on this?
>>
>>>>> Besides the compatible (which as said we need a separate one anyways),
>>>>> your other worry is code duplication, but I've avoided that as much
>>>>> as possible already, the new drivers/clk/sunxi/clk-sun6i-prcm-mod0.c is
>>>>> just a very thin wrapper, waying in with all of 63 lines including
>>>>> 16 lines GPL header.
>>>>
>>>>
>>>> 47 lines that are doing exactly the same thing as the other code is
>>>> doing. I'm sorry but you can't really argue it's not code duplication,
>>>> it really is.
>>>
>>>
>>> It is not doing the exact same thing, it is a platform driver, where as
>>> the other code is an of_clk driver.
>>>
>>>>> So sorry, I disagree I believe that this is the best solution.
>>>>>
>>>>>> However, as those are not critical clocks that need to be here early
>>>>>> at boot, you can also fix this by turning the mod0 driver into a
>>>>>> platform driver itself. The compatible will be kept, the driver will
>>>>>> be the same.
>>>>>>
>>>>>> The only thing we need to pay attention to is how "client" drivers
>>>>>> react when they cannot grab their clock. They should return
>>>>>> -EPROBE_DEFER, but that remains to be checked.
>>>>>
>>>>>
>>>>> -EPROBE_DEFER is yet another reason to not make mod0-clk a platform
>>>>> driver. Yes drivers should be able to handle this, but it is a pain,
>>>>> and the more we use it the more pain it is. Also it makes booting a lot
>>>>> slower as any driver using a mod0 clk now, will not complete its probe
>>>>> until all the other drivers are done probing and the late_initcall
>>>>> which starts the deferred-probe wq runs.
>>>>
>>>>
>>>> The whole EPROBE_DEFER mechanism might need some fixing, but it's not
>>>> really the point is it?
>>>
>>>
>>> Well one reasons why clocks are instantiated the way they are is to have
>>> them available as early as possible, which is really convenient and works
>>> really well.
>>
>>
>> Yeah, you need them early for critical and early stuff like timers,
>> console, etc. You really don't need this mechanism if you don't have
>> to handle early probed devices.
>
>
> And we do need some clocks for that, if we add the simple bus compatible
> then
> *all* of them become platform devices.
>
> Or are you suggesting to still bind all the other clocks using
> CLK_OF_DECLARE
> and only turn mod0 into a platform driver, that would be rather
> inconsistent.
>
>>> You are asking for a whole lot of stuff to be changed, arguably in a way
>>> which makes it worse, just to save 47 lines of code...
>>
>>
>> No, really, I'm not. All I ask for is adding 1 line in the DT, and
>> removing 5 lines in clk-sunxi.c. That's all.
>
>
> And adding platform driver glue for the mod0 clks, which would pretty much
> introduce the same 47 lines in a different place.
>
> I notice that you've not responded to my proposal to simple make the clock
> node a child node of the clocks node in the dt, that should work nicely, and
> avoid the need for any kernel level changes to support it, I'm beginning to
> think that that is probably the best solution.

Would that not cause an overlap of the io regions, and cause one of them
to fail? AFAIK the OF subsystem doesn't like overlapping resources.

ChenYu

Re: [PATCH 3/9] clk: sunxi: Add prcm mod0 clock driver

[Hans de Goede]

Hi,

On 11/27/2014 10:28 AM, Chen-Yu Tsai wrote:
> Hi,
>
> On Thu, Nov 27, 2014 at 4:41 PM, Hans de Goede <hdegoede@redhat.com> wrote:

<snip>

>> I notice that you've not responded to my proposal to simple make the clock
>> node a child node of the clocks node in the dt, that should work nicely, and
>> avoid the need for any kernel level changes to support it, I'm beginning to
>> think that that is probably the best solution.
>
> Would that not cause an overlap of the io regions, and cause one of them
> to fail? AFAIK the OF subsystem doesn't like overlapping resources.

No the overlap check is done by the platform dev resource code, and of_clk_declare
does not use that. So the overlap would be there, but not an issue (in theory
I did not test this).

Thinking more about this, I believe that using the MFD framework for the prcm seems
like a mistake to me. It gains us nothing, since we have no irq to de-multiplex or
some such. We're not using MFD for the CMU, why use it for CMU2 (which the prcm
effectively is) ?

So I think it would be best to remove the prcm node from the dt, and simply put the
different blocks inside it directly under the soc node, this will work fine with
current kernels, since as said we do not use any MFD features, we use it to
create platform devs and assign resources, something which will happen automatically
if we put the nodes directly under the soc node, since then simple-bus will do the
work for us.

And then in a release or 2 we can remove the mfd prcm driver from the kernel, and we
have the same functionality we have now with less code.

We could then also chose to move the existing prcm clock nodes to of_clk_declare
(this will work once they are nodes directly under soc with a proper reg property).
and the ir-clk can use allwinner,sun4i-a10-mod0-clk compatible and can live under
either clocks or soc, depending on what we want to do with the other prcm clocks.

Regards,

Hans

Re: [PATCH 3/9] clk: sunxi: Add prcm mod0 clock driver

[Boris Brezillon]

Hi,

On Wed, 26 Nov 2014 22:13:18 +0100
Maxime Ripard <maxime.ripard@free-electrons.com> wrote:

[...]

> 
> I remember someone (Chen-Yu? Boris?) saying that the 1wire clock was
> not really a mod0 clk. From what I could gather from the source code,
> it seems to have a wider m divider, so we could argue that it should
> need a new compatible.

Wasn't me :-).

Regarding the rest of the discussion I miss some context, but here's
what I remember decided us to choose the MFD approach for the PRCM
block:

1) it's embedding several unrelated functional blocks (reset, clk, and
some other things I don't remember).
2) none of the functionalities provided by the PRCM were required in
the early boot stage
3) We wanted to represent the HW blocks as they are really described in
the memory mapping instead of splitting small register chunks over the
DT.

Can someone sum-up the current issue you're trying to solve ?

IMHO, if you really want to split those functionalities over the DT
(some nodes under clks and other under reset controller), then I
suggest to use..............
(Maxime, please stop smiling :P)
..............

SYSCON

Best Regards,

Boris

-- 
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

Re: [PATCH 3/9] clk: sunxi: Add prcm mod0 clock driver

[Maxime Ripard]

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On Thu, Nov 27, 2014 at 09:41:09AM +0100, Hans de Goede wrote:
> Hi,
> 
> On 11/26/2014 10:13 PM, Maxime Ripard wrote:
> >Hi,
> >
> >On Tue, Nov 25, 2014 at 09:29:21AM +0100, Hans de Goede wrote:
> >>Hi,
> >>
> >>On 11/24/2014 11:03 PM, Maxime Ripard wrote:
> >>>On Fri, Nov 21, 2014 at 10:13:10AM +0100, Hans de Goede wrote:
> >>>>Hi,
> >>>>
> >>>>On 11/21/2014 09:49 AM, Maxime Ripard wrote:
> >>>>>Hi,
> >>>>>
> >>>>>On Thu, Nov 20, 2014 at 04:55:22PM +0100, Hans de Goede wrote:
> >>>>>>Add a driver for mod0 clocks found in the prcm. Currently there is only
> >>>>>>one mod0 clocks in the prcm, the ir clock.
> >>>>>>
> >>>>>>Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> >>>>>>---
> >>>>>>  Documentation/devicetree/bindings/clock/sunxi.txt |  1 +
> >>>>>>  drivers/clk/sunxi/Makefile                        |  2 +-
> >>>>>>  drivers/clk/sunxi/clk-sun6i-prcm-mod0.c           | 63 +++++++++++++++++++++++
> >>>>>>  drivers/mfd/sun6i-prcm.c                          | 14 +++++
> >>>>>>  4 files changed, 79 insertions(+), 1 deletion(-)
> >>>>>>  create mode 100644 drivers/clk/sunxi/clk-sun6i-prcm-mod0.c
> >>>>>>
> >>>>>>diff --git a/Documentation/devicetree/bindings/clock/sunxi.txt b/Documentation/devicetree/bindings/clock/sunxi.txt
> >>>>>>index ed116df..342c75a 100644
> >>>>>>--- a/Documentation/devicetree/bindings/clock/sunxi.txt
> >>>>>>+++ b/Documentation/devicetree/bindings/clock/sunxi.txt
> >>>>>>@@ -56,6 +56,7 @@ Required properties:
> >>>>>>  	"allwinner,sun4i-a10-usb-clk" - for usb gates + resets on A10 / A20
> >>>>>>  	"allwinner,sun5i-a13-usb-clk" - for usb gates + resets on A13
> >>>>>>  	"allwinner,sun6i-a31-usb-clk" - for usb gates + resets on A31
> >>>>>>+	"allwinner,sun6i-a31-ir-clk" - for the ir clock on A31
> >>>>>>
> >>>>>>  Required properties for all clocks:
> >>>>>>  - reg : shall be the control register address for the clock.
> >>>>>>diff --git a/drivers/clk/sunxi/Makefile b/drivers/clk/sunxi/Makefile
> >>>>>>index 7ddc2b5..daf8b1c 100644
> >>>>>>--- a/drivers/clk/sunxi/Makefile
> >>>>>>+++ b/drivers/clk/sunxi/Makefile
> >>>>>>@@ -10,4 +10,4 @@ obj-y += clk-sun8i-mbus.o
> >>>>>>
> >>>>>>  obj-$(CONFIG_MFD_SUN6I_PRCM) += \
> >>>>>>  	clk-sun6i-ar100.o clk-sun6i-apb0.o clk-sun6i-apb0-gates.o \
> >>>>>>-	clk-sun8i-apb0.o
> >>>>>>+	clk-sun8i-apb0.o clk-sun6i-prcm-mod0.o
> >>>>>>diff --git a/drivers/clk/sunxi/clk-sun6i-prcm-mod0.c b/drivers/clk/sunxi/clk-sun6i-prcm-mod0.c
> >>>>>>new file mode 100644
> >>>>>>index 0000000..e80f18e
> >>>>>>--- /dev/null
> >>>>>>+++ b/drivers/clk/sunxi/clk-sun6i-prcm-mod0.c
> >>>>>>@@ -0,0 +1,63 @@
> >>>>>>+/*
> >>>>>>+ * Allwinner A31 PRCM mod0 clock driver
> >>>>>>+ *
> >>>>>>+ * Copyright (C) 2014 Hans de Goede <hdegoede@redhat.com>
> >>>>>>+ *
> >>>>>>+ * This program is free software; you can redistribute it and/or modify
> >>>>>>+ * it under the terms of the GNU General Public License as published by
> >>>>>>+ * the Free Software Foundation; either version 2 of the License, or
> >>>>>>+ * (at your option) any later version.
> >>>>>>+ *
> >>>>>>+ * This program is distributed in the hope that it will be useful,
> >>>>>>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
> >>>>>>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> >>>>>>+ * GNU General Public License for more details.
> >>>>>>+ */
> >>>>>>+
> >>>>>>+#include <linux/clk-provider.h>
> >>>>>>+#include <linux/clkdev.h>
> >>>>>>+#include <linux/module.h>
> >>>>>>+#include <linux/of_address.h>
> >>>>>>+#include <linux/platform_device.h>
> >>>>>>+
> >>>>>>+#include "clk-factors.h"
> >>>>>>+#include "clk-mod0.h"
> >>>>>>+
> >>>>>>+static const struct of_device_id sun6i_a31_prcm_mod0_clk_dt_ids[] = {
> >>>>>>+	{ .compatible = "allwinner,sun6i-a31-ir-clk" },
> >>>>>>+	{ /* sentinel */ }
> >>>>>>+};
> >>>>>>+
> >>>>>>+static DEFINE_SPINLOCK(sun6i_prcm_mod0_lock);
> >>>>>>+
> >>>>>>+static int sun6i_a31_prcm_mod0_clk_probe(struct platform_device *pdev)
> >>>>>>+{
> >>>>>>+	struct device_node *np = pdev->dev.of_node;
> >>>>>>+	struct resource *r;
> >>>>>>+	void __iomem *reg;
> >>>>>>+
> >>>>>>+	if (!np)
> >>>>>>+		return -ENODEV;
> >>>>>>+
> >>>>>>+	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> >>>>>>+	reg = devm_ioremap_resource(&pdev->dev, r);
> >>>>>>+	if (IS_ERR(reg))
> >>>>>>+		return PTR_ERR(reg);
> >>>>>>+
> >>>>>>+	sunxi_factors_register(np, &sun4i_a10_mod0_data,
> >>>>>>+			       &sun6i_prcm_mod0_lock, reg);
> >>>>>>+	return 0;
> >>>>>>+}
> >>>>>>+
> >>>>>>+static struct platform_driver sun6i_a31_prcm_mod0_clk_driver = {
> >>>>>>+	.driver = {
> >>>>>>+		.name = "sun6i-a31-prcm-mod0-clk",
> >>>>>>+		.of_match_table = sun6i_a31_prcm_mod0_clk_dt_ids,
> >>>>>>+	},
> >>>>>>+	.probe = sun6i_a31_prcm_mod0_clk_probe,
> >>>>>>+};
> >>>>>>+module_platform_driver(sun6i_a31_prcm_mod0_clk_driver);
> >>>>>>+
> >>>>>>+MODULE_DESCRIPTION("Allwinner A31 PRCM mod0 clock driver");
> >>>>>>+MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
> >>>>>>+MODULE_LICENSE("GPL");
> >>>>>
> >>>>>I don't think this is the right approach, mainly for two reasons: the
> >>>>>compatible shouldn't change, and you're basically duplicating code
> >>>>>there.
> >>>>>
> >>>>>I understand that you need the new compatible in order to avoid a
> >>>>>double probing: one by CLK_OF_DECLARE, and one by the usual mechanism,
> >>>>>and that also implies the second reason.
> >>>>
> >>>>Not only for that, we need a new compatible also because the mfd framework
> >>>>needs a separate compatible per sub-node as that is how it finds nodes
> >>>>to attach to the platform devices, so we need a new compatible anyways,
> >>>>with your make the mod0 clock driver a platform driver solution we could
> >>>>use:
> >>>
> >>>We have a single mod0 clock in there, so no, not really.
> >>
> >>We have a single mod0 clock there today, but who knows what tomorrow brings,
> >>arguably the 1wire clock is a mod0 clock too, so we already have 2 today.
> >
> >I remember someone (Chen-Yu? Boris?) saying that the 1wire clock was
> >not really a mod0 clk. From what I could gather from the source code,
> >it seems to have a wider m divider, so we could argue that it should
> >need a new compatible.
> >
> >>>Plus, that seems like a bogus limitation from MFD, and it really
> >>>shouldn't work that way.
> >>
> >>Well AFAIK that is how it works.
> >
> >That kind of argument doesn't work. You could make exactly the same
> >statement about the fact that two identical hardware blocks in the DT
> >should have the same compatible, and it's how it works.
> >
> >With the minor exception that we can't change that fact for the DT,
> >while we can change the MTD code.
> 
> As I already said, we could do something like this to make clear this
> is a mod0 clock:
> 
> >>>>	compatible = "allwinner,sun6i-a31-ir-clk", "allwinner,sun4i-a10-mod0-clk";
> 
> The problem with that is it will cause early binding because of
> CLK_OF_DECLARE and early binding does not work on MFD instantiated devices,
> because they have no reg property.

That won't cause any early binding if you drop the CLK_OF_DECLARE and
have only a regular platform driver,  which was what I've been
suggesting all along.

> >>>>
> >>>>To work around this, but there are other problems, your make mod0clk a
> >>>>platform driver solution cannot work because the clocks node in the dtsi
> >>>>is not simple-bus compatible, so no platform-devs will be instantiated for
> >>>>the clocks there.
> >>>
> >>>Then add the simple-bus compatible.
> >>
> >>No, just no, that goes against the whole design of how of-clocks work.
> >
> >Which is... ?
> 
> That they are child nodes of a clocks node, which is NOT simple-bus compatible
> and get instantiated early using CLK_OF_DECLARE.

Depending on who you ask to, this might or might not be true. Mark
Rutland for example has been a strong opponent to that clock node. So
your it's-by-design argument is just flawed.

CLK_OF_DECLARE has been designed to be able to parse the DT early to
instantiate the early clocks. It doesn't do anything beyond that. The
clocks node has nothing to do with that whole discussion.

> >There's a number of other clocks being platform drivers, including on
> >other platforms, and as far as I know, CLK_OF_DECLARE is only really
> >useful on clocks that are critical. Mike, what's your view on this?
> >
> >>>>Besides the compatible (which as said we need a separate one anyways),
> >>>>your other worry is code duplication, but I've avoided that as much
> >>>>as possible already, the new drivers/clk/sunxi/clk-sun6i-prcm-mod0.c is
> >>>>just a very thin wrapper, waying in with all of 63 lines including
> >>>>16 lines GPL header.
> >>>
> >>>47 lines that are doing exactly the same thing as the other code is
> >>>doing. I'm sorry but you can't really argue it's not code duplication,
> >>>it really is.
> >>
> >>It is not doing the exact same thing, it is a platform driver, where as
> >>the other code is an of_clk driver.
> >>
> >>>>So sorry, I disagree I believe that this is the best solution.
> >>>>
> >>>>>However, as those are not critical clocks that need to be here early
> >>>>>at boot, you can also fix this by turning the mod0 driver into a
> >>>>>platform driver itself. The compatible will be kept, the driver will
> >>>>>be the same.
> >>>>>
> >>>>>The only thing we need to pay attention to is how "client" drivers
> >>>>>react when they cannot grab their clock. They should return
> >>>>>-EPROBE_DEFER, but that remains to be checked.
> >>>>
> >>>>-EPROBE_DEFER is yet another reason to not make mod0-clk a platform
> >>>>driver. Yes drivers should be able to handle this, but it is a pain,
> >>>>and the more we use it the more pain it is. Also it makes booting a lot
> >>>>slower as any driver using a mod0 clk now, will not complete its probe
> >>>>until all the other drivers are done probing and the late_initcall
> >>>>which starts the deferred-probe wq runs.
> >>>
> >>>The whole EPROBE_DEFER mechanism might need some fixing, but it's not
> >>>really the point is it?
> >>
> >>Well one reasons why clocks are instantiated the way they are is to have
> >>them available as early as possible, which is really convenient and works
> >>really well.
> >
> >Yeah, you need them early for critical and early stuff like timers,
> >console, etc. You really don't need this mechanism if you don't have
> >to handle early probed devices.
> 
> And we do need some clocks for that, if we add the simple bus compatible then
> *all* of them become platform devices.
> 
> Or are you suggesting to still bind all the other clocks using CLK_OF_DECLARE
> and only turn mod0 into a platform driver, that would be rather inconsistent.

Not really. Some others clocks that can be probed by MFD are already
platform drivers.

> >>You are asking for a whole lot of stuff to be changed, arguably in a way
> >>which makes it worse, just to save 47 lines of code...
> >
> >No, really, I'm not. All I ask for is adding 1 line in the DT, and
> >removing 5 lines in clk-sunxi.c. That's all.
> 
> And adding platform driver glue for the mod0 clks, which would pretty much
> introduce the same 47 lines in a different place.

What? It's exactly what your patch is doing. How is that more work?

> I notice that you've not responded to my proposal to simple make the clock
> node a child node of the clocks node in the dt, that should work nicely, and
> avoid the need for any kernel level changes to support it, I'm beginning to
> think that that is probably the best solution.

And then you're talking about inconsistencies.... Having some of these
clocks and devices exposed through MFD and some others through clocks
is very consistent indeed.

Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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Re: [PATCH 3/9] clk: sunxi: Add prcm mod0 clock driver

[Maxime Ripard]

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Hi,

On Thu, Nov 27, 2014 at 11:10:51AM +0100, Hans de Goede wrote:
> Hi,
> 
> On 11/27/2014 10:28 AM, Chen-Yu Tsai wrote:
> >Hi,
> >
> >On Thu, Nov 27, 2014 at 4:41 PM, Hans de Goede <hdegoede@redhat.com> wrote:
> 
> <snip>
> 
> >>I notice that you've not responded to my proposal to simple make the clock
> >>node a child node of the clocks node in the dt, that should work nicely, and
> >>avoid the need for any kernel level changes to support it, I'm beginning to
> >>think that that is probably the best solution.
> >
> >Would that not cause an overlap of the io regions, and cause one of them
> >to fail? AFAIK the OF subsystem doesn't like overlapping resources.
> 
> No the overlap check is done by the platform dev resource code, and of_clk_declare
> does not use that. So the overlap would be there, but not an issue (in theory
> I did not test this).

An overlap is always an issue.

> Thinking more about this, I believe that using the MFD framework for the prcm seems
> like a mistake to me. It gains us nothing, since we have no irq to de-multiplex or
> some such. We're not using MFD for the CMU, why use it for CMU2 (which the prcm
> effectively is) ?

Because the PRCM is much more than that. It also handles the power
domains for example.

And also because the 1 node per clock is no longer the current trend
and that Mike discourages to use that model nowadays.

> So I think it would be best to remove the prcm node from the dt, and simply put the
> different blocks inside it directly under the soc node, this will work fine with
> current kernels, since as said we do not use any MFD features, we use it to
> create platform devs and assign resources, something which will happen automatically
> if we put the nodes directly under the soc node, since then simple-bus will do the
> work for us.
> 
> And then in a release or 2 we can remove the mfd prcm driver from the kernel, and we
> have the same functionality we have now with less code.
> 
> We could then also chose to move the existing prcm clock nodes to of_clk_declare
> (this will work once they are nodes directly under soc with a proper reg property).
> and the ir-clk can use allwinner,sun4i-a10-mod0-clk compatible and can live under
> either clocks or soc, depending on what we want to do with the other prcm clocks.

Have you considered the SMP code in that smooth plan?

The one that is in neither a platform driver, nor a clock, nor does it
have a compatible of its own, but still needs to access some of the
PRCM registers?

Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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Re: [PATCH 3/9] clk: sunxi: Add prcm mod0 clock driver

[Maxime Ripard]

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On Thu, Nov 27, 2014 at 05:40:56PM +0100, Boris Brezillon wrote:
> Hi,
> 
> On Wed, 26 Nov 2014 22:13:18 +0100
> Maxime Ripard <maxime.ripard@free-electrons.com> wrote:
> 
> [...]
> 
> > 
> > I remember someone (Chen-Yu? Boris?) saying that the 1wire clock was
> > not really a mod0 clk. From what I could gather from the source code,
> > it seems to have a wider m divider, so we could argue that it should
> > need a new compatible.
> 
> Wasn't me :-).
> 
> Regarding the rest of the discussion I miss some context, but here's
> what I remember decided us to choose the MFD approach for the PRCM
> block:
> 
> 1) it's embedding several unrelated functional blocks (reset, clk, and
> some other things I don't remember).
> 2) none of the functionalities provided by the PRCM were required in
> the early boot stage
> 3) We wanted to represent the HW blocks as they are really described in
> the memory mapping instead of splitting small register chunks over the
> DT.
> 
> Can someone sum-up the current issue you're trying to solve ?

There's (at least) one module0 clock exposed in the PRCM block. We
have a disagreement on whether all module0 clocks should be platform
drivers to support probing that one clock or just to introduce a new
compatible for that one clock in the PRCM alone.

> IMHO, if you really want to split those functionalities over the DT
> (some nodes under clks and other under reset controller), then I
> suggest to use..............
> (Maxime, please stop smiling :P)
> ..............
> 
> SYSCON

We don't really need to share anything, these components are isolated
in separate registers, so syscon doesn't really bring anything here.

Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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Re: [PATCH 3/9] clk: sunxi: Add prcm mod0 clock driver

[Hans de Goede]

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Hi,

On 11/27/2014 08:05 PM, Maxime Ripard wrote:
> Hi,
>
> On Thu, Nov 27, 2014 at 11:10:51AM +0100, Hans de Goede wrote:
>> Hi,
>>
>> On 11/27/2014 10:28 AM, Chen-Yu Tsai wrote:
>>> Hi,
>>>
>>> On Thu, Nov 27, 2014 at 4:41 PM, Hans de Goede <hdegoede@redhat.com> wrote:
>>
>> <snip>
>>
>>>> I notice that you've not responded to my proposal to simple make the clock
>>>> node a child node of the clocks node in the dt, that should work nicely, and
>>>> avoid the need for any kernel level changes to support it, I'm beginning to
>>>> think that that is probably the best solution.
>>>
>>> Would that not cause an overlap of the io regions, and cause one of them
>>> to fail? AFAIK the OF subsystem doesn't like overlapping resources.
>>
>> No the overlap check is done by the platform dev resource code, and of_clk_declare
>> does not use that. So the overlap would be there, but not an issue (in theory
>> I did not test this).
>
> An overlap is always an issue.
>
>> Thinking more about this, I believe that using the MFD framework for the prcm seems
>> like a mistake to me. It gains us nothing, since we have no irq to de-multiplex or
>> some such. We're not using MFD for the CMU, why use it for CMU2 (which the prcm
>> effectively is) ?
>
> Because the PRCM is much more than that. It also handles the power
> domains for example.

Ok, so thinking more about this, I'm still convinced that the MFD framework is only
getting in the way here. But I can see having things represented in devicetree
properly, with the clocks, etc. as child nodes of the prcm being something which
we want.

So since all we are using the MFD for is to instantiate platform devices under the prcm
nodes, and assign an io resource for the regs to them, why not simply make the prcm node
itself a simple-bus.

This does everything the MFD prcm driver currently does, without actually needing a specific
kernel driver, and as added bonus this will move the definition of the mfd function reg offsets
out of the kernel and into the devicetree where they belong in the first place.

Please see the attached patches, I've tested this on sun6i, if we go this route we should
make the same change on sun8i (I can make the change, but not test it).

Regards,

Hans

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>From 6756574293a1f291a8dcc29427b27f32f83acb2d Mon Sep 17 00:00:00 2001
From: Hans de Goede <hdegoede@redhat.com>
Date: Fri, 28 Nov 2014 13:48:58 +0100
Subject: [PATCH v2 1/2] ARM: dts: sun6i: Change prcm node into a simple-bus

The prcm node's purpose is to group the various prcm sub-devices together,
it does not need any special handling beyond that, there is no need to
handle shared resources like a shared (multiplexed) interrupt or a shared
i2c bus.

As such there really is no need to have a separate compatible for it, using
simple-bus for it works fine. This also allows us to specify the register
offsets of the various child-devices directly into the dts, rather then having
to specify them in the OS implementation, putting the register offsets where
the belong.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 arch/arm/boot/dts/sun6i-a31.dtsi | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/arch/arm/boot/dts/sun6i-a31.dtsi b/arch/arm/boot/dts/sun6i-a31.dtsi
index 29e6438..4b8541f 100644
--- a/arch/arm/boot/dts/sun6i-a31.dtsi
+++ b/arch/arm/boot/dts/sun6i-a31.dtsi
@@ -846,11 +846,15 @@
 		};
 
 		prcm@01f01400 {
-			compatible = "allwinner,sun6i-a31-prcm";
+			compatible = "simple-bus";
 			reg = <0x01f01400 0x200>;
+			#address-cells = <1>;
+			#size-cells = <1>;
+			ranges;
 
 			ar100: ar100_clk {
 				compatible = "allwinner,sun6i-a31-ar100-clk";
+				reg = <0x01f01400 0x4>;
 				#clock-cells = <0>;
 				clocks = <&osc32k>, <&osc24M>, <&pll6>, <&pll6>;
 				clock-output-names = "ar100";
@@ -867,6 +871,7 @@
 
 			apb0: apb0_clk {
 				compatible = "allwinner,sun6i-a31-apb0-clk";
+				reg = <0x01f0140c 0x4>;
 				#clock-cells = <0>;
 				clocks = <&ahb0>;
 				clock-output-names = "apb0";
@@ -874,6 +879,7 @@
 
 			apb0_gates: apb0_gates_clk {
 				compatible = "allwinner,sun6i-a31-apb0-gates-clk";
+				reg = <0x01f01428 0x4>;
 				#clock-cells = <1>;
 				clocks = <&apb0>;
 				clock-output-names = "apb0_pio", "apb0_ir",
@@ -884,6 +890,7 @@
 
 			apb0_rst: apb0_rst {
 				compatible = "allwinner,sun6i-a31-clock-reset";
+				reg = <0x01f014b0 0x4>;
 				#reset-cells = <1>;
 			};
 		};
-- 
2.1.0


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>From a152b0405d446c748fef146915736e4a8fc548b1 Mon Sep 17 00:00:00 2001
From: Hans de Goede <hdegoede@redhat.com>
Date: Fri, 28 Nov 2014 13:54:14 +0100
Subject: [PATCH v2 2/2] ARM: dts: sun6i: Add ir_clk node

Add an ir_clk sub-node to the prcm node.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 arch/arm/boot/dts/sun6i-a31.dtsi | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/arch/arm/boot/dts/sun6i-a31.dtsi b/arch/arm/boot/dts/sun6i-a31.dtsi
index 4b8541f..92a1c95 100644
--- a/arch/arm/boot/dts/sun6i-a31.dtsi
+++ b/arch/arm/boot/dts/sun6i-a31.dtsi
@@ -888,6 +888,14 @@
 						"apb0_i2c";
 			};
 
+			ir_clk: ir_clk {
+				reg = <0x01f01454 0x4>;
+				#clock-cells = <0>;
+				compatible = "allwinner,sun4i-a10-mod0-clk";
+				clocks = <&osc32k>, <&osc24M>;
+				clock-output-names = "ir";
+			};
+
 			apb0_rst: apb0_rst {
 				compatible = "allwinner,sun6i-a31-clock-reset";
 				reg = <0x01f014b0 0x4>;
-- 
2.1.0

Re: [PATCH 3/9] clk: sunxi: Add prcm mod0 clock driver

[Maxime Ripard]

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Hi,

On Fri, Nov 28, 2014 at 02:37:14PM +0100, Hans de Goede wrote:
> Hi,
> 
> On 11/27/2014 08:05 PM, Maxime Ripard wrote:
> >Hi,
> >
> >On Thu, Nov 27, 2014 at 11:10:51AM +0100, Hans de Goede wrote:
> >>Hi,
> >>
> >>On 11/27/2014 10:28 AM, Chen-Yu Tsai wrote:
> >>>Hi,
> >>>
> >>>On Thu, Nov 27, 2014 at 4:41 PM, Hans de Goede <hdegoede@redhat.com> wrote:
> >>
> >><snip>
> >>
> >>>>I notice that you've not responded to my proposal to simple make the clock
> >>>>node a child node of the clocks node in the dt, that should work nicely, and
> >>>>avoid the need for any kernel level changes to support it, I'm beginning to
> >>>>think that that is probably the best solution.
> >>>
> >>>Would that not cause an overlap of the io regions, and cause one of them
> >>>to fail? AFAIK the OF subsystem doesn't like overlapping resources.
> >>
> >>No the overlap check is done by the platform dev resource code, and of_clk_declare
> >>does not use that. So the overlap would be there, but not an issue (in theory
> >>I did not test this).
> >
> >An overlap is always an issue.
> >
> >>Thinking more about this, I believe that using the MFD framework for the prcm seems
> >>like a mistake to me. It gains us nothing, since we have no irq to de-multiplex or
> >>some such. We're not using MFD for the CMU, why use it for CMU2 (which the prcm
> >>effectively is) ?
> >
> >Because the PRCM is much more than that. It also handles the power
> >domains for example.
> 
> Ok, so thinking more about this, I'm still convinced that the MFD
> framework is only getting in the way here.

You still haven't said of what exactly it's getting in the way of.

> But I can see having things represented in devicetree properly, with
> the clocks, etc. as child nodes of the prcm being something which we
> want.

Clocks and reset are the only thing set so far, because we need
reference to them from the DT itself, nothing more.

We could very much have more devices instatiated from the MFD itself.

> So since all we are using the MFD for is to instantiate platform
> devices under the prcm nodes, and assign an io resource for the regs
> to them, why not simply make the prcm node itself a simple-bus.

No, this is really not a bus. It shouldn't be described at all as
such. It is a device, that has multiple functionnalities in the system
=> MFD. It really is that simple.

> This does everything the MFD prcm driver currently does, without
> actually needing a specific kernel driver, and as added bonus this
> will move the definition of the mfd function reg offsets out of the
> kernel and into the devicetree where they belong in the first place.

Which was nacked in the first place because such offsets are not
supposed to be in the DT.

Really, we have something that work here, there's no need to refactor
it.

> Please see the attached patches, I've tested this on sun6i, if we go
> this route we should make the same change on sun8i (I can make the
> change, but not test it).
> 
> Regards,
> 
> Hans

> From 6756574293a1f291a8dcc29427b27f32f83acb2d Mon Sep 17 00:00:00 2001
> From: Hans de Goede <hdegoede@redhat.com>
> Date: Fri, 28 Nov 2014 13:48:58 +0100
> Subject: [PATCH v2 1/2] ARM: dts: sun6i: Change prcm node into a simple-bus
> 
> The prcm node's purpose is to group the various prcm sub-devices together,
> it does not need any special handling beyond that, there is no need to
> handle shared resources like a shared (multiplexed) interrupt or a shared
> i2c bus.
> 
> As such there really is no need to have a separate compatible for it, using
> simple-bus for it works fine. This also allows us to specify the register
> offsets of the various child-devices directly into the dts, rather then having
> to specify them in the OS implementation, putting the register offsets where
> the belong.
> 
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> ---
>  arch/arm/boot/dts/sun6i-a31.dtsi | 9 ++++++++-
>  1 file changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/arm/boot/dts/sun6i-a31.dtsi b/arch/arm/boot/dts/sun6i-a31.dtsi
> index 29e6438..4b8541f 100644
> --- a/arch/arm/boot/dts/sun6i-a31.dtsi
> +++ b/arch/arm/boot/dts/sun6i-a31.dtsi
> @@ -846,11 +846,15 @@
>  		};
>  
>  		prcm@01f01400 {
> -			compatible = "allwinner,sun6i-a31-prcm";
> +			compatible = "simple-bus";

And this breaks the SMP bringup code.

Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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Re: [PATCH 3/9] clk: sunxi: Add prcm mod0 clock driver

[Hans de Goede]

Hi,

On 12/02/2014 04:45 PM, Maxime Ripard wrote:

 >> Ok, so thinking more about this, I'm still convinced that the MFD
>> framework is only getting in the way here.
>
> You still haven't said of what exactly it's getting in the way of.

Of using of_clk_define to bind to the mod0 clk in the prcm, because the
ir_clk node does not have its own reg property when the mfd framework is
used and of_clk_define requires the node to have its own reg property.

>> But I can see having things represented in devicetree properly, with
>> the clocks, etc. as child nodes of the prcm being something which we
>> want.
>
> Clocks and reset are the only thing set so far, because we need
> reference to them from the DT itself, nothing more.
>
> We could very much have more devices instatiated from the MFD itself.
>
>> So since all we are using the MFD for is to instantiate platform
>> devices under the prcm nodes, and assign an io resource for the regs
>> to them, why not simply make the prcm node itself a simple-bus.
>
> No, this is really not a bus. It shouldn't be described at all as
> such. It is a device, that has multiple functionnalities in the system
> => MFD. It really is that simple.

Ok, I can live with that, but likewise the clocks node is not a bus either!

So it should not have a simple-bus compatible either, and as such we cannot
simply change the mod0 driver from of_clk_define to a platform driver because
then we need to instantiate platform devs for the mod0 clock nodes, which
means making the clock node a simple-bus.

I can see your logic in wanting the ir_clk prcm sub-node to use the
mod0 compatible string, so how about we make the mod0 driver both
register through of_declare and as a platform driver. Note this means
that it will try to bind twice to the ir_clk node, since of_clk_declare
will cause it to try and bind there too AFAIK.

The of_clk_declare bind will fail though because there is no regs
property, so this double bind is not an issue as long as we do not
log errors on the first bind failure.

Note that the ir_clk node will still need an "ir-clk" compatible as
well for the MFD to find it and assign the proper resources to it.

But this way we will have the clk driver binding to the mod0 clk compatible,
which is what you want, while having the MFD assign resources on the
fact that it is the ir-clk node, so that things will still work if
there are multiple mod0 clks in the prcm.

>> This does everything the MFD prcm driver currently does, without
>> actually needing a specific kernel driver, and as added bonus this
>> will move the definition of the mfd function reg offsets out of the
>> kernel and into the devicetree where they belong in the first place.
>
> Which was nacked in the first place because such offsets are not
> supposed to be in the DT.
>
> Really, we have something that work here, there's no need to refactor
> it.

Ok, but that does bring us back to the original problem wrt the ir-clk,
see above for how I think we should solve this then. If you agree I
can implement the proposed fix.

Regards,

Hans

Re: [PATCH 3/9] clk: sunxi: Add prcm mod0 clock driver

[Maxime Ripard]

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On Wed, Dec 03, 2014 at 10:49:20AM +0100, Hans de Goede wrote:
> Hi,
> 
> On 12/02/2014 04:45 PM, Maxime Ripard wrote:
> 
> >> Ok, so thinking more about this, I'm still convinced that the MFD
> >>framework is only getting in the way here.
> >
> >You still haven't said of what exactly it's getting in the way of.
> 
> Of using of_clk_define to bind to the mod0 clk in the prcm, because the
> ir_clk node does not have its own reg property when the mfd framework is
> used and of_clk_define requires the node to have its own reg property.

Yes. And the obvious solution to that is to just not use
OF_CLK_DECLARE but a platform_driver, which is totally fine.

> 
> >>But I can see having things represented in devicetree properly, with
> >>the clocks, etc. as child nodes of the prcm being something which we
> >>want.
> >
> >Clocks and reset are the only thing set so far, because we need
> >reference to them from the DT itself, nothing more.
> >
> >We could very much have more devices instatiated from the MFD itself.
> >
> >>So since all we are using the MFD for is to instantiate platform
> >>devices under the prcm nodes, and assign an io resource for the regs
> >>to them, why not simply make the prcm node itself a simple-bus.
> >
> >No, this is really not a bus. It shouldn't be described at all as
> >such. It is a device, that has multiple functionnalities in the system
> >=> MFD. It really is that simple.
> 
> Ok, I can live with that, but likewise the clocks node is not a bus either!

True, and just like we just saw with Chen-Yu patches, it can even leak
implementation details. Which was one of the arguments from Mark
against it iirc.

> So it should not have a simple-bus compatible either, and as such we cannot
> simply change the mod0 driver from of_clk_define to a platform driver because
> then we need to instantiate platform devs for the mod0 clock nodes, which
> means making the clock node a simple-bus.

I guess we can do that as a temporary measure until we get things
right on that front. I'm totally open to doing that work, so I'm not
asking you to do it.

> I can see your logic in wanting the ir_clk prcm sub-node to use the
> mod0 compatible string, so how about we make the mod0 driver both
> register through of_declare and as a platform driver. Note this means
> that it will try to bind twice to the ir_clk node, since of_clk_declare
> will cause it to try and bind there too AFAIK.

Hmmm, I could live with that for a while too. That shouldn't even
require too much work, since the first thing we check in the mod0 code
is that we actually have something in reg, which will not be the case
in the OF_CLK_DECLARE case.

> The of_clk_declare bind will fail though because there is no regs
> property, so this double bind is not an issue as long as we do not
> log errors on the first bind failure.

Yep, exactly.

> Note that the ir_clk node will still need an "ir-clk" compatible as
> well for the MFD to find it and assign the proper resources to it.

No, it really doesn't. At least for now, we have a single mod0 clock
under the PRCM MFD. If (and only if) one day, we find ourselves in a
position where we have two mod0 clocks under the PRCM, then we'll fix
the MFD code to deal with that, because it really should deal with it.

> But this way we will have the clk driver binding to the mod0 clk
> compatible, which is what you want, while having the MFD assign
> resources on the fact that it is the ir-clk node, so that things
> will still work if there are multiple mod0 clks in the prcm.

I really think having a different compatible is both wrong on a
theoritical point of view and doesn't bring anything to the table now
(and might never do)

Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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Re: [PATCH 3/9] clk: sunxi: Add prcm mod0 clock driver

[Hans de Goede]

Hi,

On 07-12-14 19:08, Maxime Ripard wrote:
> On Wed, Dec 03, 2014 at 10:49:20AM +0100, Hans de Goede wrote:

<snip>

>> So it should not have a simple-bus compatible either, and as such we cannot
>> simply change the mod0 driver from of_clk_define to a platform driver because
>> then we need to instantiate platform devs for the mod0 clock nodes, which
>> means making the clock node a simple-bus.
>
> I guess we can do that as a temporary measure until we get things
> right on that front. I'm totally open to doing that work, so I'm not
> asking you to do it.
>
>> I can see your logic in wanting the ir_clk prcm sub-node to use the
>> mod0 compatible string, so how about we make the mod0 driver both
>> register through of_declare and as a platform driver. Note this means
>> that it will try to bind twice to the ir_clk node, since of_clk_declare
>> will cause it to try and bind there too AFAIK.
>
> Hmmm, I could live with that for a while too. That shouldn't even
> require too much work, since the first thing we check in the mod0 code
> is that we actually have something in reg, which will not be the case
> in the OF_CLK_DECLARE case.
>
>> The of_clk_declare bind will fail though because there is no regs
>> property, so this double bind is not an issue as long as we do not
>> log errors on the first bind failure.
>
> Yep, exactly.
>
>> Note that the ir_clk node will still need an "ir-clk" compatible as
>> well for the MFD to find it and assign the proper resources to it.
>
> No, it really doesn't. At least for now, we have a single mod0 clock
> under the PRCM MFD. If (and only if) one day, we find ourselves in a
> position where we have two mod0 clocks under the PRCM, then we'll fix
> the MFD code to deal with that, because it really should deal with it.

Ok, using only the mod0 compat string works for me. I'll respin my
patch-set (minus the one patch you've already merged) to make the modo
clk driver use both of_clk_declare and make it a platfrom driver, and
use the mod0 compat string for the ir-clk node.

Not sure when I'll get this done exactly though, but we still have
a while before 3.20 :)

Regards,

Hans

Re: [PATCH 3/9] clk: sunxi: Add prcm mod0 clock driver

[Maxime Ripard]

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On Mon, Dec 08, 2014 at 09:19:02AM +0100, Hans de Goede wrote:
> Hi,
> 
> On 07-12-14 19:08, Maxime Ripard wrote:
> >On Wed, Dec 03, 2014 at 10:49:20AM +0100, Hans de Goede wrote:
> 
> <snip>
> 
> >>So it should not have a simple-bus compatible either, and as such we cannot
> >>simply change the mod0 driver from of_clk_define to a platform driver because
> >>then we need to instantiate platform devs for the mod0 clock nodes, which
> >>means making the clock node a simple-bus.
> >
> >I guess we can do that as a temporary measure until we get things
> >right on that front. I'm totally open to doing that work, so I'm not
> >asking you to do it.
> >
> >>I can see your logic in wanting the ir_clk prcm sub-node to use the
> >>mod0 compatible string, so how about we make the mod0 driver both
> >>register through of_declare and as a platform driver. Note this means
> >>that it will try to bind twice to the ir_clk node, since of_clk_declare
> >>will cause it to try and bind there too AFAIK.
> >
> >Hmmm, I could live with that for a while too. That shouldn't even
> >require too much work, since the first thing we check in the mod0 code
> >is that we actually have something in reg, which will not be the case
> >in the OF_CLK_DECLARE case.
> >
> >>The of_clk_declare bind will fail though because there is no regs
> >>property, so this double bind is not an issue as long as we do not
> >>log errors on the first bind failure.
> >
> >Yep, exactly.
> >
> >>Note that the ir_clk node will still need an "ir-clk" compatible as
> >>well for the MFD to find it and assign the proper resources to it.
> >
> >No, it really doesn't. At least for now, we have a single mod0 clock
> >under the PRCM MFD. If (and only if) one day, we find ourselves in a
> >position where we have two mod0 clocks under the PRCM, then we'll fix
> >the MFD code to deal with that, because it really should deal with it.
> 
> Ok, using only the mod0 compat string works for me. I'll respin my
> patch-set (minus the one patch you've already merged) to make the modo
> clk driver use both of_clk_declare and make it a platfrom driver, and
> use the mod0 compat string for the ir-clk node.
> 
> Not sure when I'll get this done exactly though, but we still have
> a while before 3.20 :)

Indeed :)

Thanks!
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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