pwm: add support for atmel-hlcdc-pwm device

Hi Thierry,

This patch series adds support for the atmel-hlcdc-pwm device provided by the atmel-hlcdc MFD driver.

Best Regards,

Boris

Changes since v9:
- replace select by depends on
- rework commit messages
- rework Kconfig description

Changes since v8:
- rework the enable/disable waiting loop
- check return code of regmap functions
- fix DT binding doc

Changes since v7:
- addressed several coding style issues

Boris Brezillon (2):
pwm: add support for atmel-hlcdc-pwm device
pwm: add DT bindings documentation for atmel-hlcdc-pwm driver

 .../devicetree/bindings/pwm/atmel-hlcdc-pwm.txt    |  29 +++
 drivers/pwm/Kconfig                                |  11 +
 drivers/pwm/Makefile                               |   1 +
 drivers/pwm/pwm-atmel-hlcdc.c                      | 259 +++++++++++++++++++++
 4 files changed, 300 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pwm/atmel-hlcdc-pwm.txt
 create mode 100644 drivers/pwm/pwm-atmel-hlcdc.c

1.9.1

The HLCDC IP available in some Atmel SoCs (i.e. at91sam9x5, at91sam9n12 or sama5d3 families for instance) provides a PWM device.

This driver add support for a PWM chip exposing a single PWM device (which will most likely be used to drive a backlight device).

---
 drivers/pwm/Kconfig           |  11 ++
 drivers/pwm/Makefile          |   1 +
 drivers/pwm/pwm-atmel-hlcdc.c | 259 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 271 insertions(+)
 create mode 100644 drivers/pwm/pwm-atmel-hlcdc.c

index b800783..6018af6 100644
@@ -50,6 +50,17 @@ config PWM_ATMEL
 	  To compile this driver as a module, choose M here: the module
 	  will be called pwm-atmel.
 
+config PWM_ATMEL_HLCDC_PWM
+	tristate "Atmel HLCDC PWM support"
+	depends on MFD_ATMEL_HLCDC
+	help
+	  Generic PWM framework driver for the PWM output of the HLCDC
+	  (Atmel High-end LCD Controller). This PWM output is mainly used
+	  to control the LCD backlight.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called pwm-atmel-hlcdc.
+
 config PWM_ATMEL_TCB
 	tristate "Atmel TC Block PWM support"
 	depends on ATMEL_TCLIB && OF

index f8c577d..eb0aae5 100644
@@ -2,6 +2,7 @@ obj-$(CONFIG_PWM)		+= core.o
 obj-$(CONFIG_PWM_SYSFS)		+= sysfs.o
 obj-$(CONFIG_PWM_AB8500)	+= pwm-ab8500.o
 obj-$(CONFIG_PWM_ATMEL)		+= pwm-atmel.o
+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_BFIN)		+= pwm-bfin.o

1.9.1

The HLCDC IP available in some Atmel SoCs (i.e. at91sam9x5, at91sam9n12 or sama5d3 families for instance) provides a PWM device.

The DT bindings used for this PWM device is following the default 3 cells bindings described in Documentation/devicetree/bindings/pwm/pwm.txt.

---
 .../devicetree/bindings/pwm/atmel-hlcdc-pwm.txt    | 29 ++++++++++++++++++++++
 1 file changed, 29 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pwm/atmel-hlcdc-pwm.txt

new file mode 100644
index 0000000..cfda0d5
@@ -0,0 +1,29 @@
+Device-Tree bindings for Atmel's HLCDC (High-end LCD Controller) PWM driver
+
+The Atmel HLCDC PWM is subdevice of the HLCDC MFD device.
+See ../mfd/atmel-hlcdc.txt for more details.
+
+Required properties:
+ - compatible: value should be one of the following:
+   "atmel,hlcdc-pwm"
+ - pinctr-names: the pin control state names. Should contain "default".
+ - pinctrl-0: should contain the pinctrl states described by pinctrl
+   default.
+ - #pwm-cells: should be set to 3. This PWM chip use the default 3 cells
+   bindings defined in pwm.txt in this directory.
+
+Example:
+
+	hlcdc: hlcdc at f0030000 {
+		compatible = "atmel,sama5d3-hlcdc";
+		reg = <0xf0030000 0x2000>;
+		clocks = <&lcdc_clk>, <&lcdck>, <&clk32k>;
+		clock-names = "periph_clk","sys_clk", "slow_clk";
+
+		hlcdc_pwm: hlcdc-pwm {
+			compatible = "atmel,hlcdc-pwm";
+			pinctrl-names = "default";
+			pinctrl-0 = <&pinctrl_lcd_pwm>;
+			#pwm-cells = <3>;
+		};
+	};

1.9.1

Hi Thierry,

You seemed to be happy with this version but never told that you would take it into your tree.

Is there anything missing (I'd really like to have the atmel-hlcdc drivers in 3.19...) ?

Best Regards,

Boris

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

Ping.

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

Applied, thanks.

Thierry
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