[U-Boot] [PATCH 2/3] sunxi: video: Add support for external DAC enable pin

Chen-Yu Tsai wens at csie.org
Mon Jan 12 11:51:22 CET 2015


On Mon, Jan 12, 2015 at 6:19 PM, Hans de Goede <hdegoede at redhat.com> wrote:
> Hi,
>
>
> On 12-01-15 11:02, Chen-Yu Tsai wrote:
>>
>> 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 at csie.org>
>> ---
>>   board/sunxi/Kconfig           |  8 ++++++++
>>   drivers/video/sunxi_display.c | 18 ++++++++++++++++++
>>   2 files changed, 26 insertions(+)
>>
>> diff --git a/board/sunxi/Kconfig b/board/sunxi/Kconfig
>> index bce270e..e9a6b3c 100644
>> --- a/board/sunxi/Kconfig
>> +++ b/board/sunxi/Kconfig
>> @@ -315,6 +315,14 @@ config VIDEO_VGA_VIA_LCD
>>         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..1052af2 100644
>> --- a/drivers/video/sunxi_display.c
>> +++ b/drivers/video/sunxi_display.c
>> @@ -813,6 +813,23 @@ static void sunxi_drc_init(void)
>>   #endif
>>   }
>>
>> +#ifdef CONFIG_VIDEO_VGA_VIA_LCD
>> +static void sunxi_vga_external_dac_enable(void)
>> +{
>> +       int pin;
>> +
>> +       /*
>> +        * Start with backlight disabled to avoid the screen flashing to
>> +        * white while the lcd inits.
>> +        */
>
>
> This comment seems wrong, copy & paste error ?
>
> Let me know if you agree that it is wrong, then I'll drop it before applying
> the series, not need to resend.

Yes it's a copy & paste error. Please drop it.

Thanks!

ChenYu

> Regards,
>
> Hans
>
>
>
>> +       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 +877,7 @@ static void sunxi_mode_set(const struct ctfb_res_modes
>> *mode,
>>                 sunxi_lcdc_tcon0_mode_set(mode);
>>                 sunxi_composer_enable();
>>                 sunxi_lcdc_enable();
>> +               sunxi_vga_external_dac_enable();
>>   #endif
>>                 break;
>>         }
>>
>


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