ARM: davinci: da850-evm: model the backlight GPIO as an actual device

Instead of enabling the panel backlight in a callback defined in board
file using deprecated legacy GPIO API calls, model the line as a GPIO
backlight device.
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>

arch/arm/mach-davinci/board-da850-evm.c

@@ -36,6 +36,7 @@
 #include <linux/platform_data/ti-aemif.h>
 #include <linux/platform_data/spi-davinci.h>
 #include <linux/platform_data/uio_pruss.h>
+#include <linux/property.h>
 #include <linux/regulator/machine.h>
 #include <linux/regulator/tps6507x.h>
 #include <linux/regulator/fixed.h>
@@ -804,34 +805,49 @@ static const short da850_evm_mmcsd0_pins[] __initconst = {
 
 static void da850_panel_power_ctrl(int val)
 {
-	/* lcd backlight */
-	gpio_set_value(DA850_LCD_BL_PIN, val);
-
 	/* lcd power */
 	gpio_set_value(DA850_LCD_PWR_PIN, val);
 }
 
+static struct property_entry da850_lcd_backlight_props[] = {
+	PROPERTY_ENTRY_BOOL("default-on"),
+	{ }
+};
+
+static struct gpiod_lookup_table da850_lcd_backlight_gpio_table = {
+	.dev_id		= "gpio-backlight",
+	.table = {
+		GPIO_LOOKUP("davinci_gpio", DA850_LCD_BL_PIN, NULL, 0),
+		{ }
+	},
+};
+
+static const struct platform_device_info da850_lcd_backlight_info = {
+	.name		= "gpio-backlight",
+	.id		= PLATFORM_DEVID_NONE,
+	.properties	= da850_lcd_backlight_props,
+};
+
 static int da850_lcd_hw_init(void)
 {
+	struct platform_device *backlight;
 	int status;
 
-	status = gpio_request(DA850_LCD_BL_PIN, "lcd bl");
-	if (status < 0)
-		return status;
+	gpiod_add_lookup_table(&da850_lcd_backlight_gpio_table);
+	backlight = platform_device_register_full(&da850_lcd_backlight_info);
+	if (IS_ERR(backlight))
+		return PTR_ERR(backlight);
 
 	status = gpio_request(DA850_LCD_PWR_PIN, "lcd pwr");
-	if (status < 0) {
-		gpio_free(DA850_LCD_BL_PIN);
+	if (status < 0)
 		return status;
-	}
 
-	gpio_direction_output(DA850_LCD_BL_PIN, 0);
 	gpio_direction_output(DA850_LCD_PWR_PIN, 0);
 
-	/* Switch off panel power and backlight */
+	/* Switch off panel power */
 	da850_panel_power_ctrl(0);
 
-	/* Switch on panel power and backlight */
+	/* Switch on panel power */
 	da850_panel_power_ctrl(1);
 
 	return 0;