avr32: use GPIO line PB15 on EVKLCD10x boards for backlight

The PB15 GPIO line is used to control the enable and disable signal for
the backlight regulator on EVKLCD10x boards. This patch hands the I/O
line over to the LCDC driver, which will control when to enable and
disable the backlight.
Signed-off-by: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>
[haavard.skinnemoen@atmel.com: reverted ac97c change]
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>

arch/avr32/boards/atngw100/evklcd10x.c

@@ -11,6 +11,7 @@
 
 #include <linux/init.h>
 #include <linux/linkage.h>
+#include <linux/gpio.h>
 #include <linux/fb.h>
 #include <linux/platform_device.h>
 
@@ -19,6 +20,7 @@
 #include <asm/setup.h>
 
 #include <mach/at32ap700x.h>
+#include <mach/portmux.h>
 #include <mach/board.h>
 
 static struct ac97c_platform_data __initdata ac97c0_data = {
@@ -144,13 +146,29 @@ static struct atmel_lcdfb_info __initdata atevklcd10x_lcdc_data = {
 };
 #endif
 
+static void atevklcd10x_lcdc_power_control(int on)
+{
+	gpio_set_value(GPIO_PIN_PB(15), on);
+}
+
 static int __init atevklcd10x_init(void)
 {
-	at32_add_device_ac97c(0, &ac97c0_data);
+	/* PB15 is connected to the enable line on the boost regulator
+	 * controlling the backlight for the LCD panel.
+	 */
+	at32_select_gpio(GPIO_PIN_PB(15), AT32_GPIOF_OUTPUT);
+	gpio_request(GPIO_PIN_PB(15), "backlight");
+	gpio_direction_output(GPIO_PIN_PB(15), 0);
+
+	atevklcd10x_lcdc_data.atmel_lcdfb_power_control =
+		atevklcd10x_lcdc_power_control;
 
 	at32_add_device_lcdc(0, &atevklcd10x_lcdc_data,
 			fbmem_start, fbmem_size,
 			ATMEL_LCDC_ALT_18BIT | ATMEL_LCDC_PE_DVAL);
+
+	at32_add_device_ac97c(0, &ac97c0_data);
+
 	return 0;
 }
 postcore_initcall(atevklcd10x_init);