Hi Andrey, On Fri, Feb 14, 2020 at 11:32:31PM +0200, Andrey Lebedev wrote: > On Fri, Feb 14, 2020 at 09:53:51AM +0100, Maxime Ripard wrote: > > On Fri, Feb 14, 2020 at 10:43:58AM +0200, Andrey Lebedev wrote: > > > On Fri, Feb 14, 2020 at 08:52:18AM +0100, Maxime Ripard wrote: > > > > > > This will create a spurious warning message for TCON1, since we > > > > > > adjusted the driver to tell it supports LVDS, but there's no LVDS > > > > > > reset line, so we need to make it finer grained. > > > > > > > > > > Yes, I can attribute two of the messages in my dmesg log [1] to this > > > > > ("Missing LVDS properties" and "LVDS output disabled". "sun4i-tcon > > > > > 1c0d000.lcd-controller" is indeed tcon1). And yes, I can see how they > > > > > can be confusing to someone. > > > > > > > > > > I'd need some pointers on how to deal with that though (if we want to do > > > > > it in this scope). > > > > > > > > Like I was mentionning, you could introduce a new compatible for each > > > > TCON (tcon0 and tcon1) and only set the support_lvds flag for tcon0 > > > > > > Can you give me an idea how that compatible might look like? > > > > > > tcon0: lcd-controller@1c0c000 { > > > compatible = "allwinner,sun7i-a20-tcon", "allwinner,lvds"; > > > > > > or > > > > > > tcon0: lcd-controller@1c0c000 { > > > compatible = "allwinner,sun7i-a20-tcon", "allwinner,tcon0"; > > > > > > ? Or something completely different? > > > > Something like > > > > &tcon0 { > > compatible = "allwinner,sun7i-a20-tcon0", "allwinner,sun7i-a20-tcon"; > > }; > > > > &tcon1 { > > compatible = "allwinner,sun7i-a20-tcon1", "allwinner,sun7i-a20-tcon"; > > }; > > > > Hi Maxime, here is what I came up with, please take a look. If the > approach is right, I'll split it up and include into the patch set. > > From f3e45c958a9551a52ac26435785bdb572e54d8db Mon Sep 17 00:00:00 2001 > From: Andrey Lebedev > Date: Fri, 14 Feb 2020 23:21:59 +0200 > Subject: [PATCH] Mark tcon0 to be the only tcon capable of LVDS on sun7i-a20 > > This allows to avoid warnings about reset line not provided for tcon1. > > Signed-off-by: Andrey Lebedev > --- > arch/arm/boot/dts/sun7i-a20.dtsi | 2 +- > drivers/gpu/drm/sun4i/sun4i_tcon.c | 22 +++++++++++++++++++++- > drivers/gpu/drm/sun4i/sun4i_tcon.h | 2 ++ > 3 files changed, 24 insertions(+), 2 deletions(-) > > diff --git a/arch/arm/boot/dts/sun7i-a20.dtsi b/arch/arm/boot/dts/sun7i-a20.dtsi > index 3b3c366a2bee..bab59fc4d9b1 100644 > --- a/arch/arm/boot/dts/sun7i-a20.dtsi > +++ b/arch/arm/boot/dts/sun7i-a20.dtsi > @@ -405,7 +405,7 @@ > }; > > tcon0: lcd-controller@1c0c000 { > - compatible = "allwinner,sun7i-a20-tcon"; > + compatible = "allwinner,sun7i-a20-tcon0", "allwinner,sun7i-a20-tcon"; That's correct > reg = <0x01c0c000 0x1000>; > interrupts = ; > resets = <&ccu RST_TCON0>, <&ccu RST_LVDS>; > diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c > index 800a9bd86112..cb2040aec436 100644 > --- a/drivers/gpu/drm/sun4i/sun4i_tcon.c > +++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c > @@ -1107,6 +1107,25 @@ static struct sunxi_engine *sun4i_tcon_find_engine(struct sun4i_drv *drv, > return sun4i_tcon_find_engine_traverse(drv, node, 0); > } > > +/* > + * Check if given tcon supports LVDS > + * > + * Some of the sunxi SoC variants contain several timing controllers, but only > + * one of them can be used to drive LVDS screen. In this case such tcon is > + * identified in respective quirks struct: lvds_compatible_tcon property will > + * hold "compatible" string of the tcon, that supports LVDS. > + * > + * If lvds_compatible_tcon is not set, all tcons are considered capable of > + * driving LVDS. > + */ > +static bool sun4i_tcon_lvds_compat(struct device *dev, struct sun4i_tcon *tcon) > +{ > + if (tcon->quirks->lvds_compatible_tcon == NULL) > + return true; > + return of_device_is_compatible(dev->of_node, > + tcon->quirks->lvds_compatible_tcon); > +} > + > static int sun4i_tcon_bind(struct device *dev, struct device *master, > void *data) > { > @@ -1161,7 +1180,7 @@ static int sun4i_tcon_bind(struct device *dev, struct device *master, > return ret; > } > > - if (tcon->quirks->supports_lvds) { > + if (tcon->quirks->supports_lvds && sun4i_tcon_lvds_compat(dev, tcon)) { > /* > * This can only be made optional since we've had DT > * nodes without the LVDS reset properties. > @@ -1481,6 +1500,7 @@ static const struct sun4i_tcon_quirks sun6i_a31s_quirks = { > > static const struct sun4i_tcon_quirks sun7i_a20_quirks = { > .supports_lvds = true, > + .lvds_compatible_tcon = "allwinner,sun7i-a20-tcon0", > .has_channel_0 = true, > .has_channel_1 = true, > .dclk_min_div = 4, > diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.h b/drivers/gpu/drm/sun4i/sun4i_tcon.h > index cfbf4e6c1679..bc87d28ee341 100644 > --- a/drivers/gpu/drm/sun4i/sun4i_tcon.h > +++ b/drivers/gpu/drm/sun4i/sun4i_tcon.h > @@ -235,6 +235,8 @@ struct sun4i_tcon_quirks { > bool needs_de_be_mux; /* sun6i needs mux to select backend */ > bool needs_edp_reset; /* a80 edp reset needed for tcon0 access */ > bool supports_lvds; /* Does the TCON support an LVDS output? */ > + /* "compatible" string of TCON that exclusively supports LVDS */ > + const char *lvds_compatible_tcon; However this is far more complicated than needed, you can simply add a new quirks structure associated to the tcon0 compatible in sun4i_tcon_of_table, and that will do Maxime