Hi Peter, Am Freitag, 7. Januar 2022, 06:13:33 CET schrieb Peter Geis: > Some implementations do not use the reset signal, instead tying it to dvdd. > Make the reset gpio optional to permit this. > > Signed-off-by: Peter Geis <pgwipe...@gmail.com> > --- > drivers/gpu/drm/panel/panel-feiyang-fy07024di26a30d.c | 11 +++++++---- > 1 file changed, 7 insertions(+), 4 deletions(-) > > diff --git a/drivers/gpu/drm/panel/panel-feiyang-fy07024di26a30d.c > b/drivers/gpu/drm/panel/panel-feiyang-fy07024di26a30d.c > index 581661b506f8..1c88d752b14e 100644 > --- a/drivers/gpu/drm/panel/panel-feiyang-fy07024di26a30d.c > +++ b/drivers/gpu/drm/panel/panel-feiyang-fy07024di26a30d.c > @@ -65,7 +65,8 @@ static int feiyang_prepare(struct drm_panel *panel) > /* T3 (dvdd rise + avdd start + avdd rise) T3 >= 20ms */ > msleep(20); > > - gpiod_set_value(ctx->reset, 0); > + if (ctx->reset) > + gpiod_set_value(ctx->reset, 0);
gpio_set_value does VALIDATE_DESC_VOID(desc); which checks for "desc" (ctx->reset in this case) to be valid and especially not null and simply returns when this is the case. So from what I see, we don't need all the added conditionals here and below and would just need the switch to devm_gpiod_get_optional alone. Heiko > > /* > * T5 + T6 (avdd rise + video & logic signal rise) > @@ -73,7 +74,8 @@ static int feiyang_prepare(struct drm_panel *panel) > */ > msleep(20); > > - gpiod_set_value(ctx->reset, 1); > + if (ctx->reset) > + gpiod_set_value(ctx->reset, 1); > > /* T12 (video & logic signal rise + backlight rise) T12 >= 200ms */ > msleep(200); > @@ -126,7 +128,8 @@ static int feiyang_unprepare(struct drm_panel *panel) > /* T13 (backlight fall + video & logic signal fall) T13 >= 200ms */ > msleep(200); > > - gpiod_set_value(ctx->reset, 0); > + if (ctx->reset) > + gpiod_set_value(ctx->reset, 0); > > regulator_disable(ctx->avdd); > > @@ -211,7 +214,7 @@ static int feiyang_dsi_probe(struct mipi_dsi_device *dsi) > return PTR_ERR(ctx->avdd); > } > > - ctx->reset = devm_gpiod_get(&dsi->dev, "reset", GPIOD_OUT_LOW); > + ctx->reset = devm_gpiod_get_optional(&dsi->dev, "reset", GPIOD_OUT_LOW); > if (IS_ERR(ctx->reset)) { > dev_err(&dsi->dev, "Couldn't get our reset GPIO\n"); > return PTR_ERR(ctx->reset); >