[PATCH v5 0/5] ARM: berlin: PWM support

[PATCH v5 0/5] ARM: berlin: PWM support

[Antoine Tenart]

Hi all,

This series adds a driver for the Marvell Berlin PWM controller, which
has 4 channels.

This has been tested on a BG2Q DMP.

Thanks,

Antoine

Changes since v4:
	- Reworked _remove()
	- Reworked _enable()

Changes since v3:
        - Use readl_relaxed
        - Reworked the clk enable / clk disable calls
        - Removed BERLIN_PWM_DISABLE

Changes since v2:
        - Reworked the prescaler/tcnt calculation
        - Added an input clock
        - Updated the documentation
        - Reordered the pwm node
        - Added some definition for BIT()

Changes since v1:
        - Added a sentinel in berlin_pwm_match[]

Antoine Tenart (5):
  pwm: add the Berlin pwm controller driver
  Documentation: bindings: document the Berlin PWM driver
  ARM: berlin: add a PWM node on the BG2Q
  ARM: berlin: add a PWM node on the BG2
  ARM: berlin: add a PWM node on the BG2CD

 .../devicetree/bindings/pwm/pwm-berlin.txt         |  19 ++
 arch/arm/boot/dts/berlin2.dtsi                     |   7 +
 arch/arm/boot/dts/berlin2cd.dtsi                   |   7 +
 arch/arm/boot/dts/berlin2q.dtsi                    |   7 +
 drivers/pwm/Kconfig                                |   9 +
 drivers/pwm/Makefile                               |   1 +
 drivers/pwm/pwm-berlin.c                           | 227 +++++++++++++++++++++
 7 files changed, 277 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pwm/pwm-berlin.txt
 create mode 100644 drivers/pwm/pwm-berlin.c

-- 
2.5.0

[PATCH v5 1/5] pwm: add the Berlin pwm controller driver

[Antoine Tenart]

Add a PWM controller driver for the Marvell Berlin SoCs. This PWM
controller has 4 channels.

Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
Acked-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
---
 drivers/pwm/Kconfig      |   9 ++
 drivers/pwm/Makefile     |   1 +
 drivers/pwm/pwm-berlin.c | 227 +++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 237 insertions(+)
 create mode 100644 drivers/pwm/pwm-berlin.c

diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index b1541f40fd8d..1773da8145b8 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -92,6 +92,15 @@ config PWM_BCM2835
 	  To compile this driver as a module, choose M here: the module
 	  will be called pwm-bcm2835.
 
+config PWM_BERLIN
+	tristate "Berlin PWM support"
+	depends on ARCH_BERLIN
+	help
+	  PWM framework driver for Berlin.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called pwm-berlin.
+
 config PWM_BFIN
 	tristate "Blackfin PWM support"
 	depends on BFIN_GPTIMERS
diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
index ec50eb5b5a8f..670c5fce8bbb 100644
--- a/drivers/pwm/Makefile
+++ b/drivers/pwm/Makefile
@@ -6,6 +6,7 @@ obj-$(CONFIG_PWM_ATMEL_HLCDC_PWM)	+= pwm-atmel-hlcdc.o
 obj-$(CONFIG_PWM_ATMEL_TCB)	+= pwm-atmel-tcb.o
 obj-$(CONFIG_PWM_BCM_KONA)	+= pwm-bcm-kona.o
 obj-$(CONFIG_PWM_BCM2835)	+= pwm-bcm2835.o
+obj-$(CONFIG_PWM_BERLIN)	+= pwm-berlin.o
 obj-$(CONFIG_PWM_BFIN)		+= pwm-bfin.o
 obj-$(CONFIG_PWM_CLPS711X)	+= pwm-clps711x.o
 obj-$(CONFIG_PWM_EP93XX)	+= pwm-ep93xx.o
diff --git a/drivers/pwm/pwm-berlin.c b/drivers/pwm/pwm-berlin.c
new file mode 100644
index 000000000000..3a373fd72892
--- /dev/null
+++ b/drivers/pwm/pwm-berlin.c
@@ -0,0 +1,227 @@
+/*
+ * Marvell Berlin PWM driver
+ *
+ * Copyright (C) 2015 Marvell Technology Group Ltd.
+ *
+ * Antoine Tenart <antoine.tenart@free-electrons.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/spinlock.h>
+
+#define BERLIN_PWM_EN			0x0
+#define BERLIN_PWM_CONTROL		0x4
+#define BERLIN_PWM_DUTY			0x8
+#define BERLIN_PWM_TCNT			0xc
+
+#define BERLIN_PWM_ENABLE		BIT(0)
+#define BERLIN_PWM_INVERT_POLARITY	BIT(3)
+#define BERLIN_PWM_PRESCALE_MASK	0x7
+#define BERLIN_PWM_PRESCALE_MAX		4096
+#define BERLIN_PWM_MAX_TCNT		65535
+
+struct berlin_pwm_chip {
+	struct pwm_chip chip;
+	struct clk *clk;
+	void __iomem *base;
+	spinlock_t lock;
+};
+
+#define to_berlin_pwm_chip(chip)	\
+	container_of((chip), struct berlin_pwm_chip, chip)
+
+#define berlin_pwm_readl(chip, channel, offset)		\
+	readl_relaxed((chip)->base + (channel) * 0x10 + offset)
+#define berlin_pwm_writel(val, chip, channel, offset)	\
+	writel_relaxed(val, (chip)->base + (channel) * 0x10 + offset)
+
+/* prescaler table: {1, 4, 8, 16, 64, 256, 1024, 4096} */
+static const u32 prescaler_diff_table[] = {
+	1, 4, 2, 2, 4, 4, 4, 4,
+};
+
+static int berlin_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm_dev,
+			     int duty_ns, int period_ns)
+{
+	struct berlin_pwm_chip *pwm = to_berlin_pwm_chip(chip);
+	int prescale = 0;
+	u32 val, duty, period;
+	u64 cycles;
+
+	cycles = clk_get_rate(pwm->clk);
+	cycles *= period_ns;
+	do_div(cycles, NSEC_PER_SEC);
+
+	while (cycles > BERLIN_PWM_MAX_TCNT)
+		do_div(cycles, prescaler_diff_table[++prescale]);
+
+	if (cycles > BERLIN_PWM_MAX_TCNT)
+		return -EINVAL;
+
+	period = cycles;
+	cycles *= duty_ns;
+	do_div(cycles, period_ns);
+	duty = cycles;
+
+	spin_lock(&pwm->lock);
+
+	val = berlin_pwm_readl(pwm, pwm_dev->hwpwm, BERLIN_PWM_CONTROL);
+	val &= ~BERLIN_PWM_PRESCALE_MASK;
+	val |= prescale;
+	berlin_pwm_writel(val, pwm, pwm_dev->hwpwm, BERLIN_PWM_CONTROL);
+
+	berlin_pwm_writel(duty, pwm, pwm_dev->hwpwm, BERLIN_PWM_DUTY);
+	berlin_pwm_writel(period, pwm, pwm_dev->hwpwm, BERLIN_PWM_TCNT);
+
+	spin_unlock(&pwm->lock);
+
+	return 0;
+}
+
+static int berlin_pwm_set_polarity(struct pwm_chip *chip,
+				   struct pwm_device *pwm_dev,
+				   enum pwm_polarity polarity)
+{
+	struct berlin_pwm_chip *pwm = to_berlin_pwm_chip(chip);
+	u32 val;
+
+	spin_lock(&pwm->lock);
+
+	val = berlin_pwm_readl(pwm, pwm_dev->hwpwm, BERLIN_PWM_CONTROL);
+
+	if (polarity == PWM_POLARITY_NORMAL)
+		val &= ~BERLIN_PWM_INVERT_POLARITY;
+	else
+		val |= BERLIN_PWM_INVERT_POLARITY;
+
+	berlin_pwm_writel(val, pwm, pwm_dev->hwpwm, BERLIN_PWM_CONTROL);
+
+	spin_unlock(&pwm->lock);
+
+	return 0;
+}
+
+static int berlin_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm_dev)
+{
+	struct berlin_pwm_chip *pwm = to_berlin_pwm_chip(chip);
+	u32 val;
+
+	spin_lock(&pwm->lock);
+
+	val = berlin_pwm_readl(pwm, pwm_dev->hwpwm, BERLIN_PWM_EN);
+	val |= BERLIN_PWM_ENABLE;
+	berlin_pwm_writel(val, pwm, pwm_dev->hwpwm, BERLIN_PWM_EN);
+
+	spin_unlock(&pwm->lock);
+
+	return 0;
+}
+
+static void berlin_pwm_disable(struct pwm_chip *chip,
+			       struct pwm_device *pwm_dev)
+{
+	struct berlin_pwm_chip *pwm = to_berlin_pwm_chip(chip);
+	u32 val;
+
+	spin_lock(&pwm->lock);
+
+	val = berlin_pwm_readl(pwm, pwm_dev->hwpwm, BERLIN_PWM_EN);
+	val &= ~BERLIN_PWM_ENABLE;
+	berlin_pwm_writel(val, pwm, pwm_dev->hwpwm, BERLIN_PWM_EN);
+
+	spin_unlock(&pwm->lock);
+}
+
+static const struct pwm_ops berlin_pwm_ops = {
+	.config = berlin_pwm_config,
+	.set_polarity = berlin_pwm_set_polarity,
+	.enable = berlin_pwm_enable,
+	.disable = berlin_pwm_disable,
+	.owner = THIS_MODULE,
+};
+
+static const struct of_device_id berlin_pwm_match[] = {
+	{ .compatible = "marvell,berlin-pwm" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, berlin_pwm_match);
+
+static int berlin_pwm_probe(struct platform_device *pdev)
+{
+	struct berlin_pwm_chip *pwm;
+	struct resource *res;
+	int ret;
+
+	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);
+
+	ret = clk_prepare_enable(pwm->clk);
+	if (ret)
+		return ret;
+
+	pwm->chip.dev = &pdev->dev;
+	pwm->chip.ops = &berlin_pwm_ops;
+	pwm->chip.base = -1;
+	pwm->chip.npwm = 4;
+	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->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);
+
+	return 0;
+}
+
+static int berlin_pwm_remove(struct platform_device *pdev)
+{
+	struct berlin_pwm_chip *pwm = platform_get_drvdata(pdev);
+	int ret;
+
+	ret = pwmchip_remove(&pwm->chip);
+	if (ret)
+		return ret;
+
+	clk_disable_unprepare(pwm->clk);
+	return 0;
+}
+
+static struct platform_driver berlin_pwm_driver = {
+	.probe	= berlin_pwm_probe,
+	.remove	= berlin_pwm_remove,
+	.driver	= {
+		.name	= "berlin-pwm",
+		.of_match_table = berlin_pwm_match,
+	},
+};
+module_platform_driver(berlin_pwm_driver);
+
+MODULE_AUTHOR("Antoine Tenart <antoine.tenart@free-electrons.com>");
+MODULE_DESCRIPTION("Marvell Berlin PWM driver");
+MODULE_LICENSE("GPL v2");
-- 
2.5.0

[PATCH v5 2/5] Documentation: bindings: document the Berlin PWM driver

[Antoine Tenart]

Following the addition of a Berlin PWM driver, this patch adds the
corresponding documentation.

Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
Acked-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
---
 Documentation/devicetree/bindings/pwm/pwm-berlin.txt | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pwm/pwm-berlin.txt

diff --git a/Documentation/devicetree/bindings/pwm/pwm-berlin.txt b/Documentation/devicetree/bindings/pwm/pwm-berlin.txt
new file mode 100644
index 000000000000..8f9bc11f8c4c
--- /dev/null
+++ b/Documentation/devicetree/bindings/pwm/pwm-berlin.txt
@@ -0,0 +1,19 @@
+Berlin PWM controller
+
+PWM IP found in Marvell Berlin SoCs.
+
+Required properties:
+- compatible: should be "marvell,berlin-pwm"
+- reg: physical base address and length of the controller's registers
+- clocks: phandle to the input clock
+- #pwm-cells: should be 3. See pwm.txt in this directory for a description of
+  the cells format.
+
+Example:
+
+pwm: pwm@f7f20000 {
+	compatible = "marvell,berlin-pwm";
+	reg = <0xf7f20000 0x40>;
+	clocks = <&chip_clk CLKID_CFG>;
+	#pwm-cells = <3>;
+}
-- 
2.5.0

[PATCH v5 3/5] ARM: berlin: add a PWM node on the BG2Q

[Antoine Tenart]

This patch adds a PWM node in the Berlin BG2Q device tree, using the
newly added Berlin PWM driver.

Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
---
 arch/arm/boot/dts/berlin2q.dtsi | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/arm/boot/dts/berlin2q.dtsi b/arch/arm/boot/dts/berlin2q.dtsi
index 63a48490e2f9..5bfa71a87617 100644
--- a/arch/arm/boot/dts/berlin2q.dtsi
+++ b/arch/arm/boot/dts/berlin2q.dtsi
@@ -477,6 +477,13 @@
 			status = "disabled";
 		};
 
+		pwm: pwm@f20000 {
+			compatible = "marvell,berlin-pwm";
+			reg = <0xf20000 0x40>;
+			clocks = <&chip_clk CLKID_CFG>;
+			#pwm-cells = <3>;
+		};
+
 		apb@fc0000 {
 			compatible = "simple-bus";
 			#address-cells = <1>;
-- 
2.5.0

[PATCH v5 4/5] ARM: berlin: add a PWM node on the BG2

[Antoine Tenart]

This patch adds a PWM node in the Berlin BG2 device tree, using the
newly added Berlin PWM driver.

Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
---
 arch/arm/boot/dts/berlin2.dtsi | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/arm/boot/dts/berlin2.dtsi b/arch/arm/boot/dts/berlin2.dtsi
index ef811de09908..f094b06d16aa 100644
--- a/arch/arm/boot/dts/berlin2.dtsi
+++ b/arch/arm/boot/dts/berlin2.dtsi
@@ -404,6 +404,13 @@
 			};
 		};
 
+		pwm: pwm@f20000 {
+			compatible = "marvell,berlin-pwm";
+			reg = <0xf20000 0x40>;
+			clocks = <&chip_clk CLKID_CFG>;
+			#pwm-cells = <3>;
+		};
+
 		apb@fc0000 {
 			compatible = "simple-bus";
 			#address-cells = <1>;
-- 
2.5.0

[PATCH v5 5/5] ARM: berlin: add a PWM node on the BG2CD

[Antoine Tenart]

This patch adds a PWM node in the Berlin BG2CD device tree, using the
newly added Berlin PWM driver.

Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
---
 arch/arm/boot/dts/berlin2cd.dtsi | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/arm/boot/dts/berlin2cd.dtsi b/arch/arm/boot/dts/berlin2cd.dtsi
index 900213d78a32..5d984f58dde7 100644
--- a/arch/arm/boot/dts/berlin2cd.dtsi
+++ b/arch/arm/boot/dts/berlin2cd.dtsi
@@ -368,6 +368,13 @@
 			status = "disabled";
 		};
 
+		pwm: pwm@f20000 {
+			compatible = "marvell,berlin-pwm";
+			reg = <0xf20000 0x40>;
+			clocks = <&chip_clk CLKID_CFG>;
+			#pwm-cells = <3>;
+		};
+
 		apb@fc0000 {
 			compatible = "simple-bus";
 			#address-cells = <1>;
-- 
2.5.0

Re: [PATCH v5 1/5] pwm: add the Berlin pwm controller driver

[Ariel D'Alessandro]

Hi Antoine,

Just one observation below.

El 26/08/15 a las 05:07, Antoine Tenart escribió:
> Add a PWM controller driver for the Marvell Berlin SoCs. This PWM
> controller has 4 channels.
> 
> Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
> Acked-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
> ---
>  drivers/pwm/Kconfig      |   9 ++
>  drivers/pwm/Makefile     |   1 +
>  drivers/pwm/pwm-berlin.c | 227 +++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 237 insertions(+)
>  create mode 100644 drivers/pwm/pwm-berlin.c
> 
> diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
> index b1541f40fd8d..1773da8145b8 100644
> --- a/drivers/pwm/Kconfig
> +++ b/drivers/pwm/Kconfig
> @@ -92,6 +92,15 @@ config PWM_BCM2835
>  	  To compile this driver as a module, choose M here: the module
>  	  will be called pwm-bcm2835.
>  
> +config PWM_BERLIN
> +	tristate "Berlin PWM support"
> +	depends on ARCH_BERLIN
> +	help
> +	  PWM framework driver for Berlin.
> +
> +	  To compile this driver as a module, choose M here: the module
> +	  will be called pwm-berlin.
> +
>  config PWM_BFIN
>  	tristate "Blackfin PWM support"
>  	depends on BFIN_GPTIMERS
> diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
> index ec50eb5b5a8f..670c5fce8bbb 100644
> --- a/drivers/pwm/Makefile
> +++ b/drivers/pwm/Makefile
> @@ -6,6 +6,7 @@ obj-$(CONFIG_PWM_ATMEL_HLCDC_PWM)	+= pwm-atmel-hlcdc.o
>  obj-$(CONFIG_PWM_ATMEL_TCB)	+= pwm-atmel-tcb.o
>  obj-$(CONFIG_PWM_BCM_KONA)	+= pwm-bcm-kona.o
>  obj-$(CONFIG_PWM_BCM2835)	+= pwm-bcm2835.o
> +obj-$(CONFIG_PWM_BERLIN)	+= pwm-berlin.o
>  obj-$(CONFIG_PWM_BFIN)		+= pwm-bfin.o
>  obj-$(CONFIG_PWM_CLPS711X)	+= pwm-clps711x.o
>  obj-$(CONFIG_PWM_EP93XX)	+= pwm-ep93xx.o
> diff --git a/drivers/pwm/pwm-berlin.c b/drivers/pwm/pwm-berlin.c
> new file mode 100644
> index 000000000000..3a373fd72892
> --- /dev/null
> +++ b/drivers/pwm/pwm-berlin.c
> @@ -0,0 +1,227 @@
> +/*
> + * Marvell Berlin PWM driver
> + *
> + * Copyright (C) 2015 Marvell Technology Group Ltd.
> + *
> + * Antoine Tenart <antoine.tenart@free-electrons.com>
> + *
> + * This file is licensed under the terms of the GNU General Public
> + * License version 2. This program is licensed "as is" without any
> + * warranty of any kind, whether express or implied.
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/io.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/pwm.h>
> +#include <linux/spinlock.h>
> +
> +#define BERLIN_PWM_EN			0x0
> +#define BERLIN_PWM_CONTROL		0x4
> +#define BERLIN_PWM_DUTY			0x8
> +#define BERLIN_PWM_TCNT			0xc
> +
> +#define BERLIN_PWM_ENABLE		BIT(0)
> +#define BERLIN_PWM_INVERT_POLARITY	BIT(3)
> +#define BERLIN_PWM_PRESCALE_MASK	0x7
> +#define BERLIN_PWM_PRESCALE_MAX		4096
> +#define BERLIN_PWM_MAX_TCNT		65535
> +
> +struct berlin_pwm_chip {
> +	struct pwm_chip chip;
> +	struct clk *clk;
> +	void __iomem *base;
> +	spinlock_t lock;
> +};
> +
> +#define to_berlin_pwm_chip(chip)	\
> +	container_of((chip), struct berlin_pwm_chip, chip)
> +
> +#define berlin_pwm_readl(chip, channel, offset)		\
> +	readl_relaxed((chip)->base + (channel) * 0x10 + offset)
> +#define berlin_pwm_writel(val, chip, channel, offset)	\
> +	writel_relaxed(val, (chip)->base + (channel) * 0x10 + offset)
> +
> +/* prescaler table: {1, 4, 8, 16, 64, 256, 1024, 4096} */
> +static const u32 prescaler_diff_table[] = {
> +	1, 4, 2, 2, 4, 4, 4, 4,
> +};
> +
> +static int berlin_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm_dev,
> +			     int duty_ns, int period_ns)
> +{
> +	struct berlin_pwm_chip *pwm = to_berlin_pwm_chip(chip);
> +	int prescale = 0;
> +	u32 val, duty, period;
> +	u64 cycles;
> +
> +	cycles = clk_get_rate(pwm->clk);
> +	cycles *= period_ns;
> +	do_div(cycles, NSEC_PER_SEC);
> +
> +	while (cycles > BERLIN_PWM_MAX_TCNT)
> +		do_div(cycles, prescaler_diff_table[++prescale]);
> +
> +	if (cycles > BERLIN_PWM_MAX_TCNT)
> +		return -EINVAL;
> +
> +	period = cycles;
> +	cycles *= duty_ns;
> +	do_div(cycles, period_ns);
> +	duty = cycles;
> +
> +	spin_lock(&pwm->lock);
> +
> +	val = berlin_pwm_readl(pwm, pwm_dev->hwpwm, BERLIN_PWM_CONTROL);
> +	val &= ~BERLIN_PWM_PRESCALE_MASK;
> +	val |= prescale;
> +	berlin_pwm_writel(val, pwm, pwm_dev->hwpwm, BERLIN_PWM_CONTROL);
> +
> +	berlin_pwm_writel(duty, pwm, pwm_dev->hwpwm, BERLIN_PWM_DUTY);
> +	berlin_pwm_writel(period, pwm, pwm_dev->hwpwm, BERLIN_PWM_TCNT);
> +
> +	spin_unlock(&pwm->lock);
> +
> +	return 0;
> +}
> +
> +static int berlin_pwm_set_polarity(struct pwm_chip *chip,
> +				   struct pwm_device *pwm_dev,
> +				   enum pwm_polarity polarity)
> +{
> +	struct berlin_pwm_chip *pwm = to_berlin_pwm_chip(chip);
> +	u32 val;
> +
> +	spin_lock(&pwm->lock);
> +
> +	val = berlin_pwm_readl(pwm, pwm_dev->hwpwm, BERLIN_PWM_CONTROL);
> +
> +	if (polarity == PWM_POLARITY_NORMAL)
> +		val &= ~BERLIN_PWM_INVERT_POLARITY;
> +	else
> +		val |= BERLIN_PWM_INVERT_POLARITY;
> +
> +	berlin_pwm_writel(val, pwm, pwm_dev->hwpwm, BERLIN_PWM_CONTROL);
> +
> +	spin_unlock(&pwm->lock);
> +
> +	return 0;
> +}
> +
> +static int berlin_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm_dev)
> +{
> +	struct berlin_pwm_chip *pwm = to_berlin_pwm_chip(chip);
> +	u32 val;
> +
> +	spin_lock(&pwm->lock);
> +
> +	val = berlin_pwm_readl(pwm, pwm_dev->hwpwm, BERLIN_PWM_EN);
> +	val |= BERLIN_PWM_ENABLE;
> +	berlin_pwm_writel(val, pwm, pwm_dev->hwpwm, BERLIN_PWM_EN);
> +
> +	spin_unlock(&pwm->lock);
> +
> +	return 0;
> +}
> +
> +static void berlin_pwm_disable(struct pwm_chip *chip,
> +			       struct pwm_device *pwm_dev)
> +{
> +	struct berlin_pwm_chip *pwm = to_berlin_pwm_chip(chip);
> +	u32 val;
> +
> +	spin_lock(&pwm->lock);
> +
> +	val = berlin_pwm_readl(pwm, pwm_dev->hwpwm, BERLIN_PWM_EN);
> +	val &= ~BERLIN_PWM_ENABLE;
> +	berlin_pwm_writel(val, pwm, pwm_dev->hwpwm, BERLIN_PWM_EN);
> +
> +	spin_unlock(&pwm->lock);
> +}
> +
> +static const struct pwm_ops berlin_pwm_ops = {
> +	.config = berlin_pwm_config,
> +	.set_polarity = berlin_pwm_set_polarity,
> +	.enable = berlin_pwm_enable,
> +	.disable = berlin_pwm_disable,
> +	.owner = THIS_MODULE,
> +};
> +
> +static const struct of_device_id berlin_pwm_match[] = {
> +	{ .compatible = "marvell,berlin-pwm" },
> +	{ },
> +};
> +MODULE_DEVICE_TABLE(of, berlin_pwm_match);
> +
> +static int berlin_pwm_probe(struct platform_device *pdev)
> +{
> +	struct berlin_pwm_chip *pwm;
> +	struct resource *res;
> +	int ret;
> +
> +	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);
> +
> +	ret = clk_prepare_enable(pwm->clk);
> +	if (ret)
> +		return ret;
> +
> +	pwm->chip.dev = &pdev->dev;
> +	pwm->chip.ops = &berlin_pwm_ops;
> +	pwm->chip.base = -1;
> +	pwm->chip.npwm = 4;
> +	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->lock);
> +
> +	ret = pwmchip_add(&pwm->chip);
> +	if (ret < 0) {
> +		dev_err(&pdev->dev, "Failed to add PWM chip: %d\n", ret);
> +		return ret;

I think you're missing some cleanup routine here. You have a previous
call to clk_prepare_enable(), so you may have a call to
clk_disable_unprepare() here in order to exit cleanly, don't you think?

> +	}
> +
> +	platform_set_drvdata(pdev, pwm);
> +
> +	return 0;
> +}
> +
> +static int berlin_pwm_remove(struct platform_device *pdev)
> +{
> +	struct berlin_pwm_chip *pwm = platform_get_drvdata(pdev);
> +	int ret;
> +
> +	ret = pwmchip_remove(&pwm->chip);
> +	if (ret)
> +		return ret;
> +
> +	clk_disable_unprepare(pwm->clk);
> +	return 0;
> +}
> +
> +static struct platform_driver berlin_pwm_driver = {
> +	.probe	= berlin_pwm_probe,
> +	.remove	= berlin_pwm_remove,
> +	.driver	= {
> +		.name	= "berlin-pwm",
> +		.of_match_table = berlin_pwm_match,
> +	},
> +};
> +module_platform_driver(berlin_pwm_driver);
> +
> +MODULE_AUTHOR("Antoine Tenart <antoine.tenart@free-electrons.com>");
> +MODULE_DESCRIPTION("Marvell Berlin PWM driver");
> +MODULE_LICENSE("GPL v2");
> 

-- 
Ariel D'Alessandro, VanguardiaSur
www.vanguardiasur.com.ar