From mboxrd@z Thu Jan 1 00:00:00 1970 From: Maxime Ripard Subject: Re: [PATCH 1/4] drm/sun4i: tcon: Support an active-low DE signal with RGB interface Date: Wed, 24 Oct 2018 17:47:58 +0100 Message-ID: <20181024164758.iqnlie4witckzauy@flea> References: <20181010114134.8211-1-contact@paulk.fr> <20181010145736.l6zpohvvd4b5qngr@flea> <224ec158bf627b4d2f577b1dadf10bd87891e2a7.camel@paulk.fr> Reply-To: maxime.ripard-LDxbnhwyfcJBDgjK7y7TUQ@public.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Return-path: Sender: linux-sunxi-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org Content-Disposition: inline In-Reply-To: <224ec158bf627b4d2f577b1dadf10bd87891e2a7.camel-W9ppeneeCTY@public.gmane.org> List-Post: , List-Help: , List-Archive: , List-Unsubscribe: , To: Paul Kocialkowski Cc: devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, dri-devel-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org, Rob Herring , Mark Rutland , Chen-Yu Tsai , Thierry Reding , David Airlie , linux-sunxi-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org, Mark Van den Borre , Gerry Demaret , Luc Verhaegen List-Id: devicetree@vger.kernel.org On Tue, Oct 23, 2018 at 11:33:10AM +0200, Paul Kocialkowski wrote: > Hi, >=20 > Le mercredi 10 octobre 2018 =C3=A0 16:57 +0200, Maxime Ripard a =C3=A9cri= t : > > On Wed, Oct 10, 2018 at 01:41:31PM +0200, Paul Kocialkowski wrote: > > > Some panels need an active-low data enable (DE) signal for the RGB > > > interface. This requires flipping a bit in the TCON0 polarity registe= r > > > when setting up the mode for the RGB interface. > > >=20 > > > Add a new helper function to match specific bus flags and use it to s= et > > > the polarity inversion bit for the DE signal when required. > > >=20 > > > Signed-off-by: Paul Kocialkowski > > > --- > > > drivers/gpu/drm/sun4i/sun4i_tcon.c | 28 ++++++++++++++++++++++++++-- > > > drivers/gpu/drm/sun4i/sun4i_tcon.h | 1 + > > > 2 files changed, 27 insertions(+), 2 deletions(-) > > >=20 > > > diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun= 4i/sun4i_tcon.c > > > index 3fb084f802e2..d249a462ec09 100644 > > > --- a/drivers/gpu/drm/sun4i/sun4i_tcon.c > > > +++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c > > > @@ -78,6 +78,24 @@ static int sun4i_tcon_get_pixel_depth(const struct= drm_encoder *encoder) > > > return -EINVAL; > > > } > > > =20 > > > +static bool sun4i_tcon_match_bus_flags(const struct drm_encoder *enc= oder, > > > + u32 bus_flags) > > > +{ > > > + struct drm_connector *connector; > > > + struct drm_display_info *info; > > > + > > > + connector =3D sun4i_tcon_get_connector(encoder); > > > + if (!connector) > > > + return false; > > > + > > > + info =3D &connector->display_info; > > > + > > > + if ((info->bus_flags & bus_flags) =3D=3D bus_flags) > > > + return true; > > > + > > > + return false; > > > +} > > > + > > > static void sun4i_tcon_channel_set_status(struct sun4i_tcon *tcon, i= nt channel, > > > bool enabled) > > > { > > > @@ -415,6 +433,7 @@ static void sun4i_tcon0_mode_set_lvds(struct sun4= i_tcon *tcon, > > > } > > > =20 > > > static void sun4i_tcon0_mode_set_rgb(struct sun4i_tcon *tcon, > > > + const struct drm_encoder *encoder, > > > const struct drm_display_mode *mode) > > > { > > > unsigned int bp, hsync, vsync; > > > @@ -474,8 +493,13 @@ static void sun4i_tcon0_mode_set_rgb(struct sun4= i_tcon *tcon, > > > if (mode->flags & DRM_MODE_FLAG_PVSYNC) > > > val |=3D SUN4I_TCON0_IO_POL_VSYNC_POSITIVE; > > > =20 > > > + if (sun4i_tcon_match_bus_flags(encoder, DRM_BUS_FLAG_DE_LOW)) > > > + val |=3D SUN4I_TCON0_IO_POL_DE_NEGATIVE; > > > + > >=20 > > There's other flags in use in that function, you should also migrate > > them (ideally by splitting that new function into a separate patch). >=20 > Actually, these other flags are not DRM bus flags but DRM mode flags, > which can be accessed directly from the mode pointer passed as > argument. Thus, they don't require a helper. I was talking about DRM_BUS_FLAG_PIXDATA_POSEDGE and DRM_BUS_FLAG_PIXDATA_NEGEDGE, which are in the current tree. Maxime --=20 Maxime Ripard, Bootlin Embedded Linux and Kernel engineering https://bootlin.com --=20 You received this message because you are subscribed to the Google Groups "= linux-sunxi" group. To unsubscribe from this group and stop receiving emails from it, send an e= mail to linux-sunxi+unsubscribe-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org For more options, visit https://groups.google.com/d/optout.