[PATCH 1/5] dt-bindings: add binding for Allwinner sun6i(A31) PWM controller

[PATCH 1/5] dt-bindings: add binding for Allwinner sun6i(A31) PWM controller

[Icenowy Zheng]

Signed-off-by: Icenowy Zheng <icenowy-ymACFijhrKM@public.gmane.org>
---
 Documentation/devicetree/bindings/pwm/pwm-sun6i.txt | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pwm/pwm-sun6i.txt

diff --git a/Documentation/devicetree/bindings/pwm/pwm-sun6i.txt b/Documentation/devicetree/bindings/pwm/pwm-sun6i.txt
new file mode 100644
index 0000000..829e0fb
--- /dev/null
+++ b/Documentation/devicetree/bindings/pwm/pwm-sun6i.txt
@@ -0,0 +1,19 @@
+Allwinner sun6i SoC PWM controller
+
+Required properties:
+  - compatible: should be one of:
+    - "allwinner,sun6i-a31-pwm"
+  - reg: physical base address and length of the controller's registers
+  - #pwm-cells: should be 3. See pwm.txt in this directory for a description of
+    the cells format.
+  - clocks: From common clock binding, handle to the parent clock.
+
+Example:
+
+	pwm0: pwm@01c21400 {
+		compatible = "allwinner,sun6i-a31-pwm";
+		reg = <0x01c21400 0x8>;
+		clocks = <&osc24M>;
+		#pwm-cells = <3>;
+		status = "disabled";
+	};
-- 
2.10.1

[PATCH 2/5] pwm: Add Allwinner A31 SoC support

[Icenowy Zheng]

This adds a generic PWM framework driver for the PWM controller found
on Allwinner A31 and A31s SoCs.

The PWM controller is different with other Allwinner SoCs, with a
control register per channel (in other SoCs the control register is
shared), and each channel are allocated 16 bytes of address (but only 8
bytes are used.)

In order to use the driver for all channels, device nodes should be
created per channel.

Signed-off-by: Icenowy Zheng <icenowy-ymACFijhrKM@public.gmane.org>
---
 drivers/pwm/Kconfig     |  10 ++
 drivers/pwm/Makefile    |   1 +
 drivers/pwm/pwm-sun6i.c | 323 ++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 334 insertions(+)
 create mode 100644 drivers/pwm/pwm-sun6i.c

diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index 80a566a..e7a0a02 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -396,6 +396,16 @@ config PWM_SUN4I
 	  To compile this driver as a module, choose M here: the module
 	  will be called pwm-sun4i.
 
+config PWM_SUN6I
+	tristate "Allwinner A31 PWM support"
+	depends on ARCH_SUNXI || COMPILE_TEST
+	depends on HAS_IOMEM && COMMON_CLK
+	help
+	  PWM framework driver for Allwinner A31 SoC.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called pwm-sun6i.
+
 config PWM_TEGRA
 	tristate "NVIDIA Tegra PWM support"
 	depends on ARCH_TEGRA
diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
index feef1dd..00b9017 100644
--- a/drivers/pwm/Makefile
+++ b/drivers/pwm/Makefile
@@ -38,6 +38,7 @@ obj-$(CONFIG_PWM_SPEAR)		+= pwm-spear.o
 obj-$(CONFIG_PWM_STI)		+= pwm-sti.o
 obj-$(CONFIG_PWM_STMPE)		+= pwm-stmpe.o
 obj-$(CONFIG_PWM_SUN4I)		+= pwm-sun4i.o
+obj-$(CONFIG_PWM_SUN6I)		+= pwm-sun6i.o
 obj-$(CONFIG_PWM_TEGRA)		+= pwm-tegra.o
 obj-$(CONFIG_PWM_TIECAP)	+= pwm-tiecap.o
 obj-$(CONFIG_PWM_TIEHRPWM)	+= pwm-tiehrpwm.o
diff --git a/drivers/pwm/pwm-sun6i.c b/drivers/pwm/pwm-sun6i.c
new file mode 100644
index 0000000..9d86944
--- /dev/null
+++ b/drivers/pwm/pwm-sun6i.c
@@ -0,0 +1,323 @@
+/*
+ * Driver for Allwinner sun6i Pulse Width Modulation Controller
+ *
+ * Copyright (C) 2016 Icenowy Zheng <icenowy-ymACFijhrKM@public.gmane.org>
+ *
+ * Derived from:
+ *   pwm-sun4i.c
+ *   Copyright (C) 2014 Alexandre Belloni <alexandre.belloni-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
+ *
+ * Licensed under GPLv2.
+ */
+
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/time.h>
+
+#define PWM_CTRL_REG		0x0
+
+#define PWM_CH_PRD		0x4
+
+#define PWMCH_OFFSET		15
+#define PWM_PRESCAL_MASK	GENMASK(3, 0)
+#define PWM_PRESCAL_OFF		0
+#define PWM_EN			BIT(4)
+#define PWM_ACT_STATE		BIT(5)
+#define PWM_CLK_GATING		BIT(6)
+#define PWM_MODE		BIT(7)
+#define PWM_PULSE		BIT(8)
+
+#define PWM_RDY		BIT(28)
+
+#define PWM_PRD(prd)		(((prd) - 1) << 16)
+#define PWM_PRD_MASK		GENMASK(15, 0)
+
+#define PWM_DTY_MASK		GENMASK(15, 0)
+
+static const u32 prescaler_table[] = {
+	1,
+	2,
+	4,
+	8,
+	16,
+	32,
+	64,
+	0,
+	0,
+	0,
+	0,
+	0,
+	0,
+	0,
+	0,
+	0,
+};
+
+struct sun6i_pwm_chip {
+	struct pwm_chip chip;
+	struct clk *clk;
+	void __iomem *base;
+	spinlock_t ctrl_lock;
+};
+
+static inline struct sun6i_pwm_chip *to_sun6i_pwm_chip(struct pwm_chip *chip)
+{
+	return container_of(chip, struct sun6i_pwm_chip, chip);
+}
+
+static inline u32 sun6i_pwm_readl(struct sun6i_pwm_chip *chip,
+				  unsigned long offset)
+{
+	return readl(chip->base + offset);
+}
+
+static inline void sun6i_pwm_writel(struct sun6i_pwm_chip *chip,
+				    u32 val, unsigned long offset)
+{
+	writel(val, chip->base + offset);
+}
+
+static int sun6i_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
+			    int duty_ns, int period_ns)
+{
+	struct sun6i_pwm_chip *sun6i_pwm = to_sun6i_pwm_chip(chip);
+	u32 prd, dty, val, clk_gate;
+	u64 clk_rate, div = 0;
+	unsigned int prescaler = 0;
+	int err;
+
+	clk_rate = clk_get_rate(sun6i_pwm->clk);
+
+	/* Go up from the first divider */
+	for (prescaler = 0; prescaler < PWM_PRESCAL_MASK; prescaler++) {
+		if (!prescaler_table[prescaler])
+			continue;
+		div = clk_rate;
+		do_div(div, prescaler_table[prescaler]);
+		div = div * period_ns;
+		do_div(div, NSEC_PER_SEC);
+		if (div - 1 <= PWM_PRD_MASK)
+			break;
+	}
+
+	if (div - 1 > PWM_PRD_MASK) {
+		dev_err(chip->dev, "period exceeds the maximum value\n");
+		return -EINVAL;
+	}
+
+	prd = div;
+	div *= duty_ns;
+	do_div(div, period_ns);
+	dty = div;
+
+	err = clk_prepare_enable(sun6i_pwm->clk);
+	if (err) {
+		dev_err(chip->dev, "failed to enable PWM clock\n");
+		return err;
+	}
+
+	spin_lock(&sun6i_pwm->ctrl_lock);
+	val = sun6i_pwm_readl(sun6i_pwm, PWM_CTRL_REG);
+
+	if (val & PWM_RDY) {
+		spin_unlock(&sun6i_pwm->ctrl_lock);
+		clk_disable_unprepare(sun6i_pwm->clk);
+		return -EBUSY;
+	}
+
+	clk_gate = val & PWM_CLK_GATING;
+	if (clk_gate) {
+		val &= ~PWM_CLK_GATING;
+		sun6i_pwm_writel(sun6i_pwm, val, PWM_CTRL_REG);
+	}
+
+	val = sun6i_pwm_readl(sun6i_pwm, PWM_CTRL_REG);
+	val &= ~PWM_PRESCAL_MASK;
+	val |= prescaler;
+	sun6i_pwm_writel(sun6i_pwm, val, PWM_CTRL_REG);
+
+	val = (dty & PWM_DTY_MASK) | PWM_PRD(prd);
+	sun6i_pwm_writel(sun6i_pwm, val, PWM_CH_PRD);
+
+	if (clk_gate) {
+		val = sun6i_pwm_readl(sun6i_pwm, PWM_CTRL_REG);
+		val |= clk_gate;
+		sun6i_pwm_writel(sun6i_pwm, val, PWM_CTRL_REG);
+	}
+
+	spin_unlock(&sun6i_pwm->ctrl_lock);
+	clk_disable_unprepare(sun6i_pwm->clk);
+
+	return 0;
+}
+
+static int sun6i_pwm_set_polarity(struct pwm_chip *chip, struct pwm_device *pwm,
+				  enum pwm_polarity polarity)
+{
+	struct sun6i_pwm_chip *sun6i_pwm = to_sun6i_pwm_chip(chip);
+	u32 val;
+	int ret;
+
+	ret = clk_prepare_enable(sun6i_pwm->clk);
+	if (ret) {
+		dev_err(chip->dev, "failed to enable PWM clock\n");
+		return ret;
+	}
+
+	spin_lock(&sun6i_pwm->ctrl_lock);
+	val = sun6i_pwm_readl(sun6i_pwm, PWM_CTRL_REG);
+
+	if (polarity != PWM_POLARITY_NORMAL)
+		val &= ~PWM_ACT_STATE;
+	else
+		val |= PWM_ACT_STATE;
+
+	sun6i_pwm_writel(sun6i_pwm, val, PWM_CTRL_REG);
+
+	spin_unlock(&sun6i_pwm->ctrl_lock);
+	clk_disable_unprepare(sun6i_pwm->clk);
+
+	return 0;
+}
+
+static int sun6i_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	struct sun6i_pwm_chip *sun6i_pwm = to_sun6i_pwm_chip(chip);
+	u32 val;
+	int ret;
+
+	ret = clk_prepare_enable(sun6i_pwm->clk);
+	if (ret) {
+		dev_err(chip->dev, "failed to enable PWM clock\n");
+		return ret;
+	}
+
+	spin_lock(&sun6i_pwm->ctrl_lock);
+	val = sun6i_pwm_readl(sun6i_pwm, PWM_CTRL_REG);
+	val |= PWM_EN;
+	val |= PWM_CLK_GATING;
+	sun6i_pwm_writel(sun6i_pwm, val, PWM_CTRL_REG);
+	spin_unlock(&sun6i_pwm->ctrl_lock);
+
+	return 0;
+}
+
+static void sun6i_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	struct sun6i_pwm_chip *sun6i_pwm = to_sun6i_pwm_chip(chip);
+	u32 val;
+
+	spin_lock(&sun6i_pwm->ctrl_lock);
+	val = sun6i_pwm_readl(sun6i_pwm, PWM_CTRL_REG);
+	val &= ~PWM_EN;
+	val &= ~PWM_CLK_GATING;
+	sun6i_pwm_writel(sun6i_pwm, val, PWM_CTRL_REG);
+	spin_unlock(&sun6i_pwm->ctrl_lock);
+
+	clk_disable_unprepare(sun6i_pwm->clk);
+}
+
+static const struct pwm_ops sun6i_pwm_ops = {
+	.config = sun6i_pwm_config,
+	.set_polarity = sun6i_pwm_set_polarity,
+	.enable = sun6i_pwm_enable,
+	.disable = sun6i_pwm_disable,
+	.owner = THIS_MODULE,
+};
+
+static const struct of_device_id sun6i_pwm_dt_ids[] = {
+	{ .compatible = "allwinner,sun6i-a31-pwm", },
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, sun6i_pwm_dt_ids);
+
+static int sun6i_pwm_probe(struct platform_device *pdev)
+{
+	struct sun6i_pwm_chip *pwm;
+	struct resource *res;
+	u32 val;
+	int ret;
+	const struct of_device_id *match;
+
+	match = of_match_device(sun6i_pwm_dt_ids, &pdev->dev);
+
+	pwm = devm_kzalloc(&pdev->dev, sizeof(*pwm), GFP_KERNEL);
+	if (!pwm)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	pwm->base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(pwm->base))
+		return PTR_ERR(pwm->base);
+
+	pwm->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(pwm->clk))
+		return PTR_ERR(pwm->clk);
+
+	pwm->chip.dev = &pdev->dev;
+	pwm->chip.ops = &sun6i_pwm_ops;
+	pwm->chip.base = -1;
+	pwm->chip.npwm = 1;
+	pwm->chip.can_sleep = true;
+	pwm->chip.of_xlate = of_pwm_xlate_with_flags;
+	pwm->chip.of_pwm_n_cells = 3;
+
+	spin_lock_init(&pwm->ctrl_lock);
+
+	ret = pwmchip_add(&pwm->chip);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "failed to add PWM chip: %d\n", ret);
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, pwm);
+
+	ret = clk_prepare_enable(pwm->clk);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to enable PWM clock\n");
+		goto clk_error;
+	}
+
+	val = sun6i_pwm_readl(pwm, PWM_CTRL_REG);
+	if (!(val & PWM_ACT_STATE))
+		pwm_set_polarity(&pwm->chip.pwms[0],
+				 PWM_POLARITY_INVERSED);
+	clk_disable_unprepare(pwm->clk);
+
+	return 0;
+
+clk_error:
+	pwmchip_remove(&pwm->chip);
+	return ret;
+}
+
+static int sun6i_pwm_remove(struct platform_device *pdev)
+{
+	struct sun6i_pwm_chip *pwm = platform_get_drvdata(pdev);
+
+	return pwmchip_remove(&pwm->chip);
+}
+
+static struct platform_driver sun6i_pwm_driver = {
+	.driver = {
+		.name = "sun6i-pwm",
+		.of_match_table = sun6i_pwm_dt_ids,
+	},
+	.probe = sun6i_pwm_probe,
+	.remove = sun6i_pwm_remove,
+};
+module_platform_driver(sun6i_pwm_driver);
+
+MODULE_ALIAS("platform:sun6i-pwm");
+MODULE_AUTHOR("Icenowy Zheng <icenowy-ymACFijhrKM@public.gmane.org>");
+MODULE_DESCRIPTION("Allwinner sun6i PWM driver");
+MODULE_LICENSE("GPL v2");
-- 
2.10.1

[PATCH 3/5] ARM: dts: sun6i: add PWM controller

[Icenowy Zheng]

The A31 and A31s SoCs feature a different PWM controller with 4
channels, all channels have dedicated control register.

Add device nodes for them.

Signed-off-by: Icenowy Zheng <icenowy-ymACFijhrKM@public.gmane.org>
---
 arch/arm/boot/dts/sun6i-a31.dtsi | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/arch/arm/boot/dts/sun6i-a31.dtsi b/arch/arm/boot/dts/sun6i-a31.dtsi
index ce19604..97626ce 100644
--- a/arch/arm/boot/dts/sun6i-a31.dtsi
+++ b/arch/arm/boot/dts/sun6i-a31.dtsi
@@ -322,6 +322,38 @@
 			#size-cells = <0>;
 		};
 
+		pwm0: pwm@01c21400 {
+			compatible = "allwinner,sun6i-a31-pwm";
+			reg = <0x01c21400 0x4>;
+			clocks = <&osc24M>;
+			#pwm-cells = <3>;
+			status = "disabled";
+		};
+
+		pwm1: pwm@01c21410 {
+			compatible = "allwinner,sun6i-a31-pwm";
+			reg = <0x01c21400 0x4>;
+			clocks = <&osc24M>;
+			#pwm-cells = <3>;
+			status = "disabled";
+		};
+
+		pwm2: pwm@01c21420 {
+			compatible = "allwinner,sun6i-a31-pwm";
+			reg = <0x01c21400 0x4>;
+			clocks = <&osc24M>;
+			#pwm-cells = <3>;
+			status = "disabled";
+		};
+
+		pwm3: pwm@01c21430 {
+			compatible = "allwinner,sun6i-a31-pwm";
+			reg = <0x01c21430 0x4>;
+			clocks = <&osc24M>;
+			#pwm-cells = <3>;
+			status = "disabled";
+		};
+
 		usb_otg: usb@01c19000 {
 			compatible = "allwinner,sun6i-a31-musb";
 			reg = <0x01c19000 0x0400>;
-- 
2.10.1

[PATCH 4/5] ARM: dts: sun6i: add pinmux for PWM0

[Icenowy Zheng]

PWM0 is used by sun6i tablets as the backlight PWM.

Add pinmux for it.

Signed-off-by: Icenowy Zheng <icenowy-ymACFijhrKM@public.gmane.org>
---
 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 97626ce..76f5a06 100644
--- a/arch/arm/boot/dts/sun6i-a31.dtsi
+++ b/arch/arm/boot/dts/sun6i-a31.dtsi
@@ -494,6 +494,13 @@
 				allwinner,pull = <SUN4I_PINCTRL_NO_PULL>;
 			};
 
+			pwm0_pins: pwm0@0 {
+				allwinner,pins = "PH13";
+				allwinner,function = "pwm0";
+				allwinner,drive = <SUN4I_PINCTRL_10_MA>;
+				allwinner,pull = <SUN4I_PINCTRL_NO_PULL>;
+			};
+
 			mmc0_pins_a: mmc0@0 {
 				allwinner,pins = "PF0", "PF1", "PF2",
 						 "PF3", "PF4", "PF5";
-- 
2.10.1

[PATCH 5/5] ARM: dts: sun6i: add pwm backlight for reference design tablet

[Icenowy Zheng]

The reference tablet design of sun6i uses pwm0 to control the backlight.

As we have PWM support for sun6i now, enable the backlight control.

Signed-off-by: Icenowy Zheng <icenowy-ymACFijhrKM@public.gmane.org>
---
 .../boot/dts/sun6i-reference-design-tablet.dtsi    | 24 ++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/arch/arm/boot/dts/sun6i-reference-design-tablet.dtsi b/arch/arm/boot/dts/sun6i-reference-design-tablet.dtsi
index c3fcf16..aa96acf 100644
--- a/arch/arm/boot/dts/sun6i-reference-design-tablet.dtsi
+++ b/arch/arm/boot/dts/sun6i-reference-design-tablet.dtsi
@@ -45,6 +45,7 @@
 #include <dt-bindings/gpio/gpio.h>
 #include <dt-bindings/input/input.h>
 #include <dt-bindings/pinctrl/sun4i-a10.h>
+#include <dt-bindings/pwm/pwm.h>
 
 / {
 	aliases {
@@ -54,6 +55,16 @@
 	chosen {
 		stdout-path = "serial0:115200n8";
 	};
+
+	backlight: backlight {
+		compatible = "pwm-backlight";
+		pinctrl-names = "default";
+		pinctrl-0 = <&bl_en_pin>;
+		pwms = <&pwm0 0 50000 PWM_POLARITY_INVERTED>;
+		brightness-levels = <0 10 20 30 40 50 60 70 80 90 100>;
+		default-brightness-level = <8>;
+		enable-gpios = <&pio 0 25 GPIO_ACTIVE_HIGH>; /* PA25 */
+	};
 };
 
 &cpu0 {
@@ -76,6 +87,13 @@
 };
 
 &pio {
+	bl_en_pin: bl_en_pin@0 {
+		allwinner,pins = "PA25";
+		allwinner,function = "gpio_in";
+		allwinner,drive = <SUN4I_PINCTRL_10_MA>;
+		allwinner,pull = <SUN4I_PINCTRL_NO_PULL>;
+	};
+
 	mmc0_cd_pin_e708_q1: mmc0_cd_pin@0 {
 		allwinner,pins = "PA8";
 		allwinner,function = "gpio_in";
@@ -91,6 +109,12 @@
 	};
 };
 
+&pwm0 {
+	pinctrl-names = "default";
+	pinctrl-0 = <&pwm0_pins>;
+	status = "okay";
+};
+
 &p2wi {
 	status = "okay";
 
-- 
2.10.1

Re: [linux-sunxi] [PATCH 2/5] pwm: Add Allwinner A31 SoC support

[LABBE Corentin]

Hello

I have a minor comment below

On Tue, Oct 11, 2016 at 02:34:46PM +0800, Icenowy Zheng wrote:
> This adds a generic PWM framework driver for the PWM controller found
> on Allwinner A31 and A31s SoCs.
> 
> The PWM controller is different with other Allwinner SoCs, with a
> control register per channel (in other SoCs the control register is
> shared), and each channel are allocated 16 bytes of address (but only 8
> bytes are used.)
> 
> In order to use the driver for all channels, device nodes should be
> created per channel.
> 
> Signed-off-by: Icenowy Zheng <icenowy@aosc.xyz>
> ---
>  drivers/pwm/Kconfig     |  10 ++
>  drivers/pwm/Makefile    |   1 +
>  drivers/pwm/pwm-sun6i.c | 323 ++++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 334 insertions(+)
>  create mode 100644 drivers/pwm/pwm-sun6i.c
> 
> +
> +static int sun6i_pwm_probe(struct platform_device *pdev)
> +{
> +	struct sun6i_pwm_chip *pwm;
> +	struct resource *res;
> +	u32 val;
> +	int ret;
> +	const struct of_device_id *match;
> +
> +	match = of_match_device(sun6i_pwm_dt_ids, &pdev->dev);

match is not used after.

Regards

Corentin Labbe

Re: [PATCH 2/5] pwm: Add Allwinner A31 SoC support

[LABBE Corentin]

Hello

I have a minor comment below

On Tue, Oct 11, 2016 at 02:34:46PM +0800, Icenowy Zheng wrote:
> This adds a generic PWM framework driver for the PWM controller found
> on Allwinner A31 and A31s SoCs.
> 
> The PWM controller is different with other Allwinner SoCs, with a
> control register per channel (in other SoCs the control register is
> shared), and each channel are allocated 16 bytes of address (but only 8
> bytes are used.)
> 
> In order to use the driver for all channels, device nodes should be
> created per channel.
> 
> Signed-off-by: Icenowy Zheng <icenowy-ymACFijhrKM@public.gmane.org>
> ---
>  drivers/pwm/Kconfig     |  10 ++
>  drivers/pwm/Makefile    |   1 +
>  drivers/pwm/pwm-sun6i.c | 323 ++++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 334 insertions(+)
>  create mode 100644 drivers/pwm/pwm-sun6i.c
> 
> +
> +static int sun6i_pwm_probe(struct platform_device *pdev)
> +{
> +	struct sun6i_pwm_chip *pwm;
> +	struct resource *res;
> +	u32 val;
> +	int ret;
> +	const struct of_device_id *match;
> +
> +	match = of_match_device(sun6i_pwm_dt_ids, &pdev->dev);

match is not used after.

Regards

Corentin Labbe

Re: [PATCH 2/5] pwm: Add Allwinner A31 SoC support

[Maxime Ripard]

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Hi,

On Tue, Oct 11, 2016 at 02:34:46PM +0800, Icenowy Zheng wrote:
> This adds a generic PWM framework driver for the PWM controller found
> on Allwinner A31 and A31s SoCs.
> 
> The PWM controller is different with other Allwinner SoCs, with a
> control register per channel (in other SoCs the control register is
> shared), and each channel are allocated 16 bytes of address (but only 8
> bytes are used.)
> 
> In order to use the driver for all channels, device nodes should be
> created per channel.

I don't think there's any need for a new driver that duplicates most
of the logic. The bitfields look roughly the same, and the only
difference is the split difference.

This is something that can easily be handled without creating a new
driver using regmap's reg_field, or through an intermediate functino
that returns the register offset.

Maxime

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

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Re: [PATCH 2/5] pwm: Add Allwinner A31 SoC support

[Maxime Ripard]

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Hi,

On Tue, Oct 11, 2016 at 02:34:46PM +0800, Icenowy Zheng wrote:
> This adds a generic PWM framework driver for the PWM controller found
> on Allwinner A31 and A31s SoCs.
> 
> The PWM controller is different with other Allwinner SoCs, with a
> control register per channel (in other SoCs the control register is
> shared), and each channel are allocated 16 bytes of address (but only 8
> bytes are used.)
> 
> In order to use the driver for all channels, device nodes should be
> created per channel.

I don't think there's any need for a new driver that duplicates most
of the logic. The bitfields look roughly the same, and the only
difference is the split difference.

This is something that can easily be handled without creating a new
driver using regmap's reg_field, or through an intermediate functino
that returns the register offset.

Maxime

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

[PATCH 5/5] ARM: dts: sun6i: add pwm backlight for reference design tablet

[Icenowy Zheng]

The reference tablet design of sun6i uses pwm0 to control the backlight.

As we have PWM support for sun6i now, enable the backlight control.

Signed-off-by: Icenowy Zheng <icenowy-ymACFijhrKM@public.gmane.org>
---
 .../boot/dts/sun6i-reference-design-tablet.dtsi    | 24 ++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/arch/arm/boot/dts/sun6i-reference-design-tablet.dtsi b/arch/arm/boot/dts/sun6i-reference-design-tablet.dtsi
index c3fcf16..aa96acf 100644
--- a/arch/arm/boot/dts/sun6i-reference-design-tablet.dtsi
+++ b/arch/arm/boot/dts/sun6i-reference-design-tablet.dtsi
@@ -45,6 +45,7 @@
 #include <dt-bindings/gpio/gpio.h>
 #include <dt-bindings/input/input.h>
 #include <dt-bindings/pinctrl/sun4i-a10.h>
+#include <dt-bindings/pwm/pwm.h>
 
 / {
 	aliases {
@@ -54,6 +55,16 @@
 	chosen {
 		stdout-path = "serial0:115200n8";
 	};
+
+	backlight: backlight {
+		compatible = "pwm-backlight";
+		pinctrl-names = "default";
+		pinctrl-0 = <&bl_en_pin>;
+		pwms = <&pwm0 0 50000 PWM_POLARITY_INVERTED>;
+		brightness-levels = <0 10 20 30 40 50 60 70 80 90 100>;
+		default-brightness-level = <8>;
+		enable-gpios = <&pio 0 25 GPIO_ACTIVE_HIGH>; /* PA25 */
+	};
 };
 
 &cpu0 {
@@ -76,6 +87,13 @@
 };
 
 &pio {
+	bl_en_pin: bl_en_pin@0 {
+		allwinner,pins = "PA25";
+		allwinner,function = "gpio_in";
+		allwinner,drive = <SUN4I_PINCTRL_10_MA>;
+		allwinner,pull = <SUN4I_PINCTRL_NO_PULL>;
+	};
+
 	mmc0_cd_pin_e708_q1: mmc0_cd_pin@0 {
 		allwinner,pins = "PA8";
 		allwinner,function = "gpio_in";
@@ -91,6 +109,12 @@
 	};
 };
 
+&pwm0 {
+	pinctrl-names = "default";
+	pinctrl-0 = <&pwm0_pins>;
+	status = "okay";
+};
+
 &p2wi {
 	status = "okay";
 
-- 
2.10.1