sunxi: video: Add support for external DAC enable pin
The external DAC for VGA output might have either a power or reset
control pin that needs to be pulled up, as is the case on the
Hummingbird A31.
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
diff --git a/board/sunxi/Kconfig b/board/sunxi/Kconfig
index 5822b41..c5105bb 100644
--- a/board/sunxi/Kconfig
+++ b/board/sunxi/Kconfig
@@ -314,6 +314,14 @@
LCD interface driving a VGA connector, such as found on the
Olimex A13 boards.
+config VIDEO_VGA_EXTERNAL_DAC_EN
+ string "LCD panel power enable pin"
+ depends on VIDEO_VGA_VIA_LCD
+ default ""
+ ---help---
+ Set the enable pin for the external VGA DAC. 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_MODE
string "LCD panel timing details"
depends on VIDEO
diff --git a/drivers/video/sunxi_display.c b/drivers/video/sunxi_display.c
index 47d820d..d92dfa8 100644
--- a/drivers/video/sunxi_display.c
+++ b/drivers/video/sunxi_display.c
@@ -813,6 +813,19 @@
#endif
}
+#ifdef CONFIG_VIDEO_VGA_VIA_LCD
+static void sunxi_vga_external_dac_enable(void)
+{
+ int pin;
+
+ pin = sunxi_name_to_gpio(CONFIG_VIDEO_VGA_EXTERNAL_DAC_EN);
+ if (pin != -1) {
+ gpio_request(pin, "vga_enable");
+ gpio_direction_output(pin, 1);
+ }
+}
+#endif /* CONFIG_VIDEO_VGA_VIA_LCD */
+
static void sunxi_engines_init(void)
{
sunxi_composer_init();
@@ -860,6 +873,7 @@
sunxi_lcdc_tcon0_mode_set(mode);
sunxi_composer_enable();
sunxi_lcdc_enable();
+ sunxi_vga_external_dac_enable();
#endif
break;
}