[PATCH v7 0/5] ARM: berlin: PWM support

[PATCH v7 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 v6:
        - Used a prescaler_table again
        - Removed the spinlock
        - Used inline function for read/write
        - Always disable the clock in _remvove()
        - Cosmtic updates
	- Reordered the Documentation patch

Changes since v5:
        - Rebased on top of 4.3-rc1
        - Added a call to clk_disable_unprepare() in case of failure

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):
  Documentation: bindings: document the Berlin PWM driver
  pwm: add the Berlin pwm controller 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         |  17 ++
 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                           | 221 +++++++++++++++++++++
 7 files changed, 269 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pwm/pwm-berlin.txt
 create mode 100644 drivers/pwm/pwm-berlin.c

-- 
2.6.0

[PATCH v7 1/5] 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 | 17 +++++++++++++++++
 1 file changed, 17 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..82cbe16fcbbc
--- /dev/null
+++ b/Documentation/devicetree/bindings/pwm/pwm-berlin.txt
@@ -0,0 +1,17 @@
+Berlin PWM controller
+
+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>;
+}
-- 
2.6.0

[PATCH v7 2/5] 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 | 221 +++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 231 insertions(+)
 create mode 100644 drivers/pwm/pwm-berlin.c

diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index 062630ab7424..f3e8b7566ce5 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 a0e00c09ead3..601833d82da5 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_CRC)		+= pwm-crc.o
diff --git a/drivers/pwm/pwm-berlin.c b/drivers/pwm/pwm-berlin.c
new file mode 100644
index 000000000000..981038740577
--- /dev/null
+++ b/drivers/pwm/pwm-berlin.c
@@ -0,0 +1,221 @@
+/*
+ * Marvell Berlin PWM driver
+ *
+ * Copyright (C) 2015 Marvell Technology Group Ltd.
+ *
+ * Author: 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>
+
+#define BERLIN_PWM_EN			0x0
+#define  BERLIN_PWM_ENABLE		BIT(0)
+#define BERLIN_PWM_CONTROL		0x4
+#define  BERLIN_PWM_PRESCALE_MASK	0x7
+#define  BERLIN_PWM_PRESCALE_MAX	4096
+#define  BERLIN_PWM_INVERT_POLARITY	BIT(3)
+#define BERLIN_PWM_DUTY			0x8
+#define BERLIN_PWM_TCNT			0xc
+#define  BERLIN_PWM_MAX_TCNT		65535
+
+struct berlin_pwm_chip {
+	struct pwm_chip chip;
+	struct clk *clk;
+	void __iomem *base;
+};
+
+#define to_berlin_pwm_chip(chip)	\
+	container_of((chip), struct berlin_pwm_chip, chip)
+
+static const u32 prescaler_table[] = {
+	1, 4, 8, 16, 64, 256, 1024, 4096
+};
+
+static inline u32 berlin_pwm_readl(struct berlin_pwm_chip *chip,
+				   unsigned int channel, unsigned long offset)
+{
+	return readl_relaxed(chip->base + channel * 0x10 + offset);
+}
+
+static inline void berlin_pwm_writel(struct berlin_pwm_chip *chip,
+				     unsigned int channel, u32 val,
+				     unsigned long offset)
+{
+	writel_relaxed(val, chip->base + channel * 0x10 + offset);
+}
+
+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);
+	unsigned int prescale;
+	u32 val, duty, period;
+	u64 cycles, tmp;
+
+	cycles = clk_get_rate(pwm->clk);
+	cycles *= period_ns;
+	do_div(cycles, NSEC_PER_SEC);
+
+	for (prescale = 0; prescale < ARRAY_SIZE(prescaler_table); prescale++) {
+		tmp = cycles;
+		do_div(tmp, prescaler_table[prescale]);
+
+		if (tmp <= BERLIN_PWM_MAX_TCNT)
+			break;
+	}
+
+	if (tmp > BERLIN_PWM_MAX_TCNT)
+		goto err_range;
+
+	period = tmp;
+	cycles = tmp * duty_ns;
+	do_div(cycles, period_ns);
+	duty = cycles;
+
+	val = berlin_pwm_readl(pwm, pwm_dev->hwpwm, BERLIN_PWM_CONTROL);
+	val &= ~BERLIN_PWM_PRESCALE_MASK;
+	val |= prescale;
+	berlin_pwm_writel(pwm, pwm_dev->hwpwm, val, BERLIN_PWM_CONTROL);
+
+	berlin_pwm_writel(pwm, pwm_dev->hwpwm, duty, BERLIN_PWM_DUTY);
+	berlin_pwm_writel(pwm, pwm_dev->hwpwm, period, BERLIN_PWM_TCNT);
+
+	return 0;
+
+err_range:
+	return -ERANGE;
+}
+
+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;
+
+	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(pwm, pwm_dev->hwpwm, val, BERLIN_PWM_CONTROL);
+
+	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;
+
+	val = berlin_pwm_readl(pwm, pwm_dev->hwpwm, BERLIN_PWM_EN);
+	val |= BERLIN_PWM_ENABLE;
+	berlin_pwm_writel(pwm, pwm_dev->hwpwm, val, BERLIN_PWM_EN);
+
+	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;
+
+	val = berlin_pwm_readl(pwm, pwm_dev->hwpwm, BERLIN_PWM_EN);
+	val &= ~BERLIN_PWM_ENABLE;
+	berlin_pwm_writel(pwm, pwm_dev->hwpwm, val, BERLIN_PWM_EN);
+}
+
+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;
+
+	ret = pwmchip_add(&pwm->chip);
+	if (ret < 0) {
+		clk_disable_unprepare(pwm->clk);
+
+		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);
+	clk_disable_unprepare(pwm->clk);
+
+	return ret;
+}
+
+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");
-- 
2.6.0

[PATCH v7 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>;
-- 
2.6.0

[PATCH v7 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>;
-- 
2.6.0

[PATCH v7 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>;
-- 
2.6.0

Re: [PATCH v7 1/5] Documentation: bindings: document the Berlin PWM driver

[Thierry Reding]

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On Fri, Oct 02, 2015 at 04:59:46PM +0200, Antoine Tenart wrote:
> 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 | 17 +++++++++++++++++
>  1 file changed, 17 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/pwm/pwm-berlin.txt

Applied, thanks.

Thierry

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Re: [PATCH v7 2/5] pwm: add the Berlin pwm controller driver

[Thierry Reding]

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On Fri, Oct 02, 2015 at 04:59:47PM +0200, Antoine Tenart wrote:
> 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 | 221 +++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 231 insertions(+)
>  create mode 100644 drivers/pwm/pwm-berlin.c

Applied, with minor tweaks, thanks.

Thierry

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Re: [PATCH v7 3/5] ARM: berlin: add a PWM node on the BG2Q

[Sebastian Hesselbarth]

On 02.10.2015 16:59, Antoine Tenart wrote:
> 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(+)

Applied this and the next two for BG2 and BG2CD
to berlin/dt.

Thanks,
   Sebastian

> 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>;
>

[PATCH] pwm: berlin: fix build warning

[Arnd Bergmann]

The newly added berlin pwm driver causes a build warning:

drivers/pwm/pwm-berlin.c: In function 'berlin_pwm_config':
drivers/pwm/pwm-berlin.c:61:32: warning: initialization makes pointer from integer without a cast [-Wint-conversion]
  struct berlin_pwm_chip *pwm = to_berlin_pwm_chip(chip);

This changes the prototype of the to_berlin_pwm_chip() the way it
was meant to be.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
On Monday 05 October 2015 16:30:15 Thierry Reding wrote:
> On Fri, Oct 02, 2015 at 04:59:47PM +0200, Antoine Tenart wrote:
> > 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 | 221 +++++++++++++++++++++++++++++++++++++++++++++++
> >  3 files changed, 231 insertions(+)
> >  create mode 100644 drivers/pwm/pwm-berlin.c
> 
> Applied, with minor tweaks, thanks.

Apparently the tweak has failed 

diff --git a/drivers/pwm/pwm-berlin.c b/drivers/pwm/pwm-berlin.c
index a390de6a760f..97933d3b2cc4 100644
--- a/drivers/pwm/pwm-berlin.c
+++ b/drivers/pwm/pwm-berlin.c
@@ -33,7 +33,7 @@ struct berlin_pwm_chip {
 	void __iomem *base;
 };
 
-static inline to_berlin_pwm_chip(struct pwm_chip *chip)
+static inline struct berlin_pwm_chip *to_berlin_pwm_chip(struct pwm_chip *chip)
 {
 	return container_of((chip), struct berlin_pwm_chip, chip);
 }