Re: [PATCH v1 1/2] drm/msm/dp: Add support for SC7280 eDP

On Thu 12 Aug 19:28 CDT 2021, sbillaka@codeaurora.org wrote:

On 2021-08-12 06:11, Stephen Boyd wrote:

...

Quoting Sankeerth Billakanti (2021-08-11 17:08:01)

[..]

...

...

+static int dp_parser_gpio(struct dp_parser *parser) +{

•   struct device *dev = &parser->pdev->dev;
  

•   int ret;
  

•   parser->panel_bklt_gpio = devm_gpiod_get(dev, "panel-bklt",
  

•                   GPIOD_OUT_HIGH);
  

•   if (IS_ERR(parser->panel_bklt_gpio)) {
  

•           ret = PTR_ERR(parser->panel_bklt_gpio);
  

•           parser->panel_bklt_gpio = NULL;
  

•           DRM_ERROR("%s: cannot get panel-bklt gpio, %d\n",
  

__func__, ret);

•           goto fail;
  

•   }
  

•   parser->panel_pwm_gpio = devm_gpiod_get(dev, "panel-pwm",
  

GPIOD_OUT_HIGH);

•   if (IS_ERR(parser->panel_pwm_gpio)) {
  

•           ret = PTR_ERR(parser->panel_pwm_gpio);
  

•           parser->panel_pwm_gpio = NULL;
  

•           DRM_ERROR("%s: cannot get panel-pwm gpio, %d\n",
  

__func__, ret);

•           goto fail;
  

•   }
  

•   DRM_INFO("gpio on");
  

+fail:

•   return 0;
  

+}

Don't we have pwm backlight drivers like drivers/video/backlight/pwm_bl.c to support this? This sort of thing doesn't belong in the dp driver.

Okay. I will explore it.

I proposed that we attach a drm_panel and allow that to control the (pwm-)backlight. Here's the link for the DP patch:

https://lore.kernel.org/linux-arm-msm/20210726231351.655302-1-bjorn.andersso...

Regards, Bjorn