From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from perceval.ideasonboard.com ([95.142.166.194]:39763 "EHLO perceval.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756531AbaCQN4x (ORCPT ); Mon, 17 Mar 2014 09:56:53 -0400 From: Laurent Pinchart To: Andrzej Hajda Cc: Denis Carikli , Philipp Zabel , devel@driverdev.osuosl.org, Russell King , Eric =?ISO-8859-1?Q?B=E9nard?= , David Airlie , Greg Kroah-Hartman , linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, Sascha Hauer , Shawn Guo , linux-arm-kernel@lists.infradead.org, Mauro Carvalho Chehab Subject: Re: [PATCH 07/12] drm: drm_display_mode: add signal polarity flags Date: Mon, 17 Mar 2014 14:58:36 +0100 Message-ID: <2166863.3Fn4k2rvaz@avalon> In-Reply-To: <5326FB75.1050605@samsung.com> References: <1394731053-6118-1-git-send-email-denis@eukrea.com> <1394731053-6118-7-git-send-email-denis@eukrea.com> <5326FB75.1050605@samsung.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-media-owner@vger.kernel.org List-ID: Hello, On Monday 17 March 2014 14:41:09 Andrzej Hajda wrote: > On 03/13/2014 06:17 PM, Denis Carikli wrote: > > We need a way to pass signal polarity informations > > between DRM panels, and the display drivers. > > > > To do that, a pol_flags field was added to drm_display_mode. > > > > Signed-off-by: Denis Carikli > > --- > > ChangeLog v10->v11: > > - Since the imx-drm won't be able to retrive its regulators > > > > from the device tree when using display-timings nodes, > > and that I was told that the drm simple-panel driver > > already supported that, I then, instead, added what was > > lacking to make the eukrea displays work with the > > drm-simple-panel driver. > > > > That required a way to get back the display polarity > > informations from the imx-drm driver without affecting > > userspace. > > > > --- > > > > include/drm/drm_crtc.h | 8 ++++++++ > > 1 file changed, 8 insertions(+) > > > > diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h > > index f764654..61a4fe1 100644 > > --- a/include/drm/drm_crtc.h > > +++ b/include/drm/drm_crtc.h > > @@ -131,6 +131,13 @@ enum drm_mode_status { > > > > #define DRM_MODE_FLAG_3D_MAX DRM_MODE_FLAG_3D_SIDE_BY_SIDE_HALF > > > > +#define DRM_MODE_FLAG_POL_PIXDATA_NEGEDGE BIT(1) > > +#define DRM_MODE_FLAG_POL_PIXDATA_POSEDGE BIT(2) > > +#define DRM_MODE_FLAG_POL_PIXDATA_PRESERVE BIT(3) > > +#define DRM_MODE_FLAG_POL_DE_NEGEDGE BIT(4) > > +#define DRM_MODE_FLAG_POL_DE_POSEDGE BIT(5) > > +#define DRM_MODE_FLAG_POL_DE_PRESERVE BIT(6) > > Could you add some description to these flags. > What are *_PRESERVE flags for? > Are those flags 1:1 compatible with respective 'videomode:flags'? > I guess DE flags should be rather DRM_MODE_FLAG_POL_DE_(LOW|HIGH), am I > right? Possibly nitpicking, I wouldn't call the clock edge on which data signals are generated/sampled "data polarity". This is clock polarity information. Have you seen cases where pixel data and DE are geenrated or need to be sampled on different edges ? > > + > > struct drm_display_mode { > > /* Header */ > > struct list_head head; > > @@ -183,6 +190,7 @@ struct drm_display_mode { > > int vrefresh; /* in Hz */ > > int hsync; /* in kHz */ > > enum hdmi_picture_aspect picture_aspect_ratio; > > + unsigned int pol_flags; > > }; > > > > static inline bool drm_mode_is_stereo(const struct drm_display_mode > > *mode) -- Regards, Laurent Pinchart