ARM: SAMSUNG: Add PWM backlight support on Samsung S5PV210

This patch adds support for LCD backlight control using PWM timer
for Samsung's SMDKV210 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-s5pv210/Kconfig b/arch/arm/mach-s5pv210/Kconfig
index 53aabef1e9ce..d7fd031f6015 100644
--- a/arch/arm/mach-s5pv210/Kconfig
+++ b/arch/arm/mach-s5pv210/Kconfig
@@ -130,6 +130,7 @@ config MACH_SMDKV210
         select SAMSUNG_DEV_ADC
         select SAMSUNG_DEV_IDE
         select SAMSUNG_DEV_KEYPAD
+        select SAMSUNG_DEV_PWM
         select SAMSUNG_DEV_TS
         select S5PV210_SETUP_FB_24BPP
         select S5PV210_SETUP_I2C1
diff --git a/arch/arm/mach-s5pv210/mach-smdkv210.c b/arch/arm/mach-s5pv210/mach-smdkv210.c
index bc9fdb52a020..2b5f48806c57 100644
--- a/arch/arm/mach-s5pv210/mach-smdkv210.c
+++ b/arch/arm/mach-s5pv210/mach-smdkv210.c
@@ -18,6 +18,7 @@
 #include <linux/fb.h>
 #include <linux/gpio.h>
 #include <linux/delay.h>
+#include <linux/pwm_backlight.h>
 
 #include <asm/mach/arch.h>
 #include <asm/mach/map.h>
@@ -43,6 +44,7 @@
 #include <plat/keypad.h>
 #include <plat/pm.h>
 #include <plat/fb.h>
+#include <plat/gpio-cfg.h>
 
 /* Following are default values for UCON, ULCON and UFCON UART registers */
 #define SMDKV210_UCON_DEFAULT   (S3C2410_UCON_TXILEVEL |        \
@@ -208,6 +210,45 @@ static struct s3c_fb_platdata smdkv210_lcd0_pdata __initdata = {
         .setup_gpio     = s5pv210_fb_gpio_setup_24bpp,
 };
 
+static int smdkv210_backlight_init(struct device *dev)
+{
+        int ret;
+
+        ret = gpio_request(S5PV210_GPD0(3), "Backlight");
+        if (ret) {
+                printk(KERN_ERR "failed to request GPD for PWM-OUT 3\n");
+                return ret;
+        }
+
+        /* Configure GPIO pin with S5PV210_GPD_0_3_TOUT_3 */
+        s3c_gpio_cfgpin(S5PV210_GPD0(3), S3C_GPIO_SFN(2));
+
+        return 0;
+}
+
+static void smdkv210_backlight_exit(struct device *dev)
+{
+        s3c_gpio_cfgpin(S5PV210_GPD0(3), S3C_GPIO_OUTPUT);
+        gpio_free(S5PV210_GPD0(3));
+}
+
+static struct platform_pwm_backlight_data smdkv210_backlight_data = {
+        .pwm_id         = 3,
+        .max_brightness = 255,
+        .dft_brightness = 255,
+        .pwm_period_ns  = 78770,
+        .init           = smdkv210_backlight_init,
+        .exit           = smdkv210_backlight_exit,
+};
+
+static struct platform_device smdkv210_backlight_device = {
+        .name           = "pwm-backlight",
+        .dev            = {
+                .parent         = &s3c_device_timer[3].dev,
+                .platform_data  = &smdkv210_backlight_data,
+        },
+};
+
 static struct platform_device *smdkv210_devices[] __initdata = {
         &s3c_device_adc,
         &s3c_device_cfcon,
@@ -229,6 +270,8 @@ static struct platform_device *smdkv210_devices[] __initdata = {
         &samsung_device_keypad,
         &smdkv210_dm9000,
         &smdkv210_lcd_lte480wv,
+        &s3c_device_timer[3],
+        &smdkv210_backlight_device,
 };
 
 static void __init smdkv210_dm9000_init(void)