sunxi: video: Make pwm polarity configurable

It turns out that there are some panels where the pwm input is not active low,
so make it configurable.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Ian Campbell <ijc@hellion.org.uk>

diff --git a/board/sunxi/Kconfig b/board/sunxi/Kconfig
index 0e3c2076dc12b64c2aefe0781c1e2a3f9ab4f096..738b55e74aba83d477f28bcc782d2a97f74d9140 100644 (file)
--- a/board/sunxi/Kconfig
+++ b/board/sunxi/Kconfig
@@ -319,6 +319,13 @@ config VIDEO_LCD_BL_PWM
        Set the backlight pwm pin for the LCD panel. This takes a string in the
        format understood by sunxi_name_to_gpio, e.g. PH1 for pin 1 of port H.
 
+config VIDEO_LCD_BL_PWM_ACTIVE_LOW
+       bool "LCD panel backlight pwm is inverted"
+       depends on VIDEO
+       default y
+       ---help---
+       Set this if the backlight pwm output is active low.
+
 
 # Note only one of these may be selected at a time! But hidden choices are
 # not supported by Kconfig

diff --git a/drivers/video/sunxi_display.c b/drivers/video/sunxi_display.c
index 5077111daf90e44f4eb8be3519636cd94f3851a9..af728b51c746783e46d3edc06b01538814dd44ea 100644 (file)
--- a/drivers/video/sunxi_display.c
+++ b/drivers/video/sunxi_display.c
@@ -23,6 +23,14 @@
 #include "hitachi_tx18d42vm_lcd.h"
 #include "ssd2828.h"
 
+#ifdef CONFIG_VIDEO_LCD_BL_PWM_ACTIVE_LOW
+#define PWM_ON 0
+#define PWM_OFF 1
+#else
+#define PWM_ON 1
+#define PWM_OFF 0
+#endif
+
 DECLARE_GLOBAL_DATA_PTR;
 
 enum sunxi_monitor {
@@ -598,8 +606,7 @@ static void sunxi_lcdc_panel_enable(void)
        pin = sunxi_name_to_gpio(CONFIG_VIDEO_LCD_BL_PWM);
        if (pin != -1) {
                gpio_request(pin, "lcd_backlight_pwm");
-               /* backlight pwm is inverted, set to 1 to disable backlight */
-               gpio_direction_output(pin, 1);
+               gpio_direction_output(pin, PWM_OFF);
        }
 
        /* Give the backlight some time to turn off and power up the panel. */
@@ -626,10 +633,8 @@ static void sunxi_lcdc_backlight_enable(void)
                gpio_direction_output(pin, 1);
 
        pin = sunxi_name_to_gpio(CONFIG_VIDEO_LCD_BL_PWM);
-       if (pin != -1) {
-               /* backlight pwm is inverted, set to 0 to enable backlight */
-               gpio_direction_output(pin, 0);
-       }
+       if (pin != -1)
+               gpio_direction_output(pin, PWM_ON);
 }
 
 static int sunxi_lcdc_get_clk_delay(const struct ctfb_res_modes *mode)