ARM: SAMSUNG: Add PWM backlight support on Samsung S5P6450

This patch adds support for LCD backlight control using PWM timer
for Samsung SMDK6450 board.

Signed-off-by: Banajit Goswami <banajit.g@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>

2 files changed, 44 insertions, 0 deletions

diff --git a/arch/arm/mach-s5p64x0/Kconfig b/arch/arm/mach-s5p64x0/Kconfig
index be5888a0e20b..08b0a5bf1d60 100644
--- a/arch/arm/mach-s5p64x0/Kconfig
+++ b/arch/arm/mach-s5p64x0/Kconfig
@@ -48,6 +48,7 @@ config MACH_SMDK6450
         select S3C_DEV_WDT
         select S3C64XX_DEV_SPI
         select SAMSUNG_DEV_ADC
+        select SAMSUNG_DEV_PWM
         select SAMSUNG_DEV_TS
         select S5P64X0_SETUP_I2C1
         help
diff --git a/arch/arm/mach-s5p64x0/mach-smdk6450.c b/arch/arm/mach-s5p64x0/mach-smdk6450.c
index 3a20de0a9264..1d8f9fd5af3a 100644
--- a/arch/arm/mach-s5p64x0/mach-smdk6450.c
+++ b/arch/arm/mach-s5p64x0/mach-smdk6450.c
@@ -22,6 +22,7 @@
 #include <linux/module.h>
 #include <linux/clk.h>
 #include <linux/gpio.h>
+#include <linux/pwm_backlight.h>
 
 #include <asm/mach/arch.h>
 #include <asm/mach/map.h>
@@ -32,6 +33,7 @@
 #include <mach/map.h>
 #include <mach/regs-clock.h>
 #include <mach/i2c.h>
+#include <mach/regs-gpio.h>
 
 #include <plat/regs-serial.h>
 #include <plat/gpio-cfg.h>
@@ -106,6 +108,45 @@ static struct s3c2410_uartcfg smdk6450_uartcfgs[] __initdata = {
 #endif
 };
 
+static int smdk6450_backlight_init(struct device *dev)
+{
+        int ret;
+
+        ret = gpio_request(S5P6450_GPF(15), "Backlight");
+        if (ret) {
+                printk(KERN_ERR "failed to request GPF for PWM-OUT1\n");
+                return ret;
+        }
+
+        /* Configure GPIO pin with S5P6450_GPF15_PWM_TOUT1 */
+        s3c_gpio_cfgpin(S5P6450_GPF(15), S3C_GPIO_SFN(2));
+
+        return 0;
+}
+
+static void smdk6450_backlight_exit(struct device *dev)
+{
+        s3c_gpio_cfgpin(S5P6450_GPF(15), S3C_GPIO_OUTPUT);
+        gpio_free(S5P6450_GPF(15));
+}
+
+static struct platform_pwm_backlight_data smdk6450_backlight_data = {
+        .pwm_id         = 1,
+        .max_brightness = 255,
+        .dft_brightness = 255,
+        .pwm_period_ns  = 78770,
+        .init           = smdk6450_backlight_init,
+        .exit           = smdk6450_backlight_exit,
+};
+
+static struct platform_device smdk6450_backlight_device = {
+        .name           = "pwm-backlight",
+        .dev            = {
+                .parent         = &s3c_device_timer[1].dev,
+                .platform_data  = &smdk6450_backlight_data,
+        },
+};
+
 static struct platform_device *smdk6450_devices[] __initdata = {
         &s3c_device_adc,
         &s3c_device_rtc,
@@ -115,6 +156,8 @@ static struct platform_device *smdk6450_devices[] __initdata = {
         &s3c_device_wdt,
         &samsung_asoc_dma,
         &s5p6450_device_iis0,
+        &s3c_device_timer[1],
+        &smdk6450_backlight_device,
         /* s5p6450_device_spi0 will be added */
 };