On Wed, Apr 12, 2023 at 09:46:00PM +0200, Konrad Dybcio wrote: > This chip supports controlling the backlight via DCS commands, on at > least some panels. Add support for doing so. > > Note this may only concern the NT36523*W* variant. Nobody knows, really, > there's no docs. > > Signed-off-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxx> > --- > drivers/gpu/drm/panel/panel-novatek-nt36523.c | 67 +++++++++++++++++++++++++-- > 1 file changed, 64 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/panel/panel-novatek-nt36523.c b/drivers/gpu/drm/panel/panel-novatek-nt36523.c > index d30dbbfb67b1..3c81ec014eef 100644 > --- a/drivers/gpu/drm/panel/panel-novatek-nt36523.c > +++ b/drivers/gpu/drm/panel/panel-novatek-nt36523.c > @@ -5,6 +5,7 @@ > * Copyright (c) 2022, 2023 Jianhua Lu <lujianhua000@xxxxxxxxx> > */ > > + [..] > +static struct backlight_device *nt36523_create_backlight(struct mipi_dsi_device *dsi) > +{ > + struct device *dev = &dsi->dev; > + const struct backlight_properties props = { > + .type = BACKLIGHT_RAW, > + .brightness = 512, > + .max_brightness = 4095, Please set the missing scale property of backlight. Daniel said: "Unknown is never correct for new drivers." See https://lore.kernel.org/lkml/Y6SIWoVFX%2FOlNO0n@xxxxxxxxx/ Otherwise, Reviewed-by: Jianhua Lu <lujianhua000@xxxxxxxxx> > + }; > + > + return devm_backlight_device_register(dev, dev_name(dev), dev, dsi, > + &nt36523_bl_ops, &props); > +} > + > static int nt36523_probe(struct mipi_dsi_device *dsi) > { > struct device *dev = &dsi->dev; > @@ -730,9 +784,16 @@ static int nt36523_probe(struct mipi_dsi_device *dsi) > mipi_dsi_set_drvdata(dsi, pinfo); > drm_panel_init(&pinfo->panel, dev, &nt36523_panel_funcs, DRM_MODE_CONNECTOR_DSI); > > - ret = drm_panel_of_backlight(&pinfo->panel); > - if (ret) > - return dev_err_probe(dev, ret, "failed to get backlight\n"); > + if (pinfo->desc->has_dcs_backlight) { > + pinfo->panel.backlight = nt36523_create_backlight(dsi); > + if (IS_ERR(pinfo->panel.backlight)) > + return dev_err_probe(dev, PTR_ERR(pinfo->panel.backlight), > + "Failed to create backlight\n"); > + } else { > + ret = drm_panel_of_backlight(&pinfo->panel); > + if (ret) > + return dev_err_probe(dev, ret, "Failed to get backlight\n"); > + } > > drm_panel_add(&pinfo->panel); > > > -- > 2.40.0 >