ARM: SAMSUNG: Add PWM backlight support on Samsung S5P6440

This patch adds support for LCD backlight control using PWM timer
for Samsung SMDK6440 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 164d2783d381..be5888a0e20b 100644
--- a/arch/arm/mach-s5p64x0/Kconfig
+++ b/arch/arm/mach-s5p64x0/Kconfig
@@ -34,6 +34,7 @@ config MACH_SMDK6440
         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-smdk6440.c b/arch/arm/mach-s5p64x0/mach-smdk6440.c
index e5beb84e2393..366dca4ec794 100644
--- a/arch/arm/mach-s5p64x0/mach-smdk6440.c
+++ b/arch/arm/mach-s5p64x0/mach-smdk6440.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>
@@ -88,6 +90,45 @@ static struct s3c2410_uartcfg smdk6440_uartcfgs[] __initdata = {
         },
 };
 
+static int smdk6440_backlight_init(struct device *dev)
+{
+        int ret;
+
+        ret = gpio_request(S5P6440_GPF(15), "Backlight");
+        if (ret) {
+                printk(KERN_ERR "failed to request GPF for PWM-OUT1\n");
+                return ret;
+        }
+
+        /* Configure GPIO pin with S5P6440_GPF15_PWM_TOUT1 */
+        s3c_gpio_cfgpin(S5P6440_GPF(15), S3C_GPIO_SFN(2));
+
+        return 0;
+}
+
+static void smdk6440_backlight_exit(struct device *dev)
+{
+        s3c_gpio_cfgpin(S5P6440_GPF(15), S3C_GPIO_OUTPUT);
+        gpio_free(S5P6440_GPF(15));
+}
+
+static struct platform_pwm_backlight_data smdk6440_backlight_data = {
+        .pwm_id         = 1,
+        .max_brightness = 255,
+        .dft_brightness = 255,
+        .pwm_period_ns  = 78770,
+        .init           = smdk6440_backlight_init,
+        .exit           = smdk6440_backlight_exit,
+};
+
+static struct platform_device smdk6440_backlight_device = {
+        .name           = "pwm-backlight",
+        .dev            = {
+                .parent         = &s3c_device_timer[1].dev,
+                .platform_data  = &smdk6440_backlight_data,
+        },
+};
+
 static struct platform_device *smdk6440_devices[] __initdata = {
         &s3c_device_adc,
         &s3c_device_rtc,
@@ -97,6 +138,8 @@ static struct platform_device *smdk6440_devices[] __initdata = {
         &s3c_device_wdt,
         &samsung_asoc_dma,
         &s5p6440_device_iis,
+        &s3c_device_timer[1],
+        &smdk6440_backlight_device,
 };
 
 static struct s3c2410_platform_i2c s5p6440_i2c0_data __initdata = {