pwm: Add Renesas TPU PWM driver

The Timer Pulse Unit (TPU) is a 4-channels 16-bit timer used to generate
waveforms. This driver exposes PWM functions through the PWM API for
other drivers to use.

The code is loosely based on the leds-renesas-tpu driver by Magnus Damm
and the TPU PWM driver shipped in the Armadillo EVA 800 kernel sources.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Tested-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

drivers/pwm/Kconfig

@@ -128,6 +128,16 @@ config PWM_PXA
 	  To compile this driver as a module, choose M here: the module
 	  will be called pwm-pxa.
 
+config PWM_RENESAS_TPU
+	tristate "Renesas TPU PWM support"
+	depends on ARCH_SHMOBILE
+	help
+	  This driver exposes the Timer Pulse Unit (TPU) PWM controller found
+	  in Renesas chips through the PWM API.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called pwm-renesas-tpu.
+
 config PWM_SAMSUNG
 	tristate "Samsung PWM support"
 	depends on PLAT_SAMSUNG

drivers/pwm/Makefile

@@ -10,6 +10,7 @@ obj-$(CONFIG_PWM_MXS)		+= pwm-mxs.o
 obj-$(CONFIG_PWM_PCA9685)	+= pwm-pca9685.o
 obj-$(CONFIG_PWM_PUV3)		+= pwm-puv3.o
 obj-$(CONFIG_PWM_PXA)		+= pwm-pxa.o
+obj-$(CONFIG_PWM_RENESAS_TPU)	+= pwm-renesas-tpu.o
 obj-$(CONFIG_PWM_SAMSUNG)	+= pwm-samsung.o
 obj-$(CONFIG_PWM_SPEAR)		+= pwm-spear.o
 obj-$(CONFIG_PWM_TEGRA)		+= pwm-tegra.o

include/linux/platform_data/pwm-renesas-tpu.h

+#ifndef __PWM_RENESAS_TPU_H__
+#define __PWM_RENESAS_TPU_H__
+
+#include <linux/pwm.h>
+
+#define TPU_CHANNEL_MAX		4
+
+struct tpu_pwm_channel_data {
+	enum pwm_polarity polarity;
+};
+
+struct tpu_pwm_platform_data {
+	struct tpu_pwm_channel_data channels[TPU_CHANNEL_MAX];
+};
+
+#endif /* __PWM_RENESAS_TPU_H__ */