On Thu 12 Aug 19:28 CDT 2021, sbillaka@xxxxxxxxxxxxxx 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.andersson@xxxxxxxxxx/ Regards, Bjorn