From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steffen Trumtrar Date: Wed, 27 Feb 2013 16:05:40 +0000 Subject: Re: [PATCH v17 2/7] video: add display_timing and videomode Message-Id: <20130227160540.GA10491@pengutronix.de> List-Id: References: <1359104515-8907-1-git-send-email-s.trumtrar@pengutronix.de> <1359104515-8907-3-git-send-email-s.trumtrar@pengutronix.de> <51223615.4090709@iki.fi> <512E2A1B.6040704@ti.com> In-Reply-To: <512E2A1B.6040704@ti.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Tomi Valkeinen Cc: devicetree-discuss@lists.ozlabs.org, Dave Airlie , Rob Herring , linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org, Laurent Pinchart , Thierry Reding , Guennady Liakhovetski , linux-media@vger.kernel.org, Stephen Warren , Florian Tobias Schandinat , Rob Clark , Leela Krishna Amudala , "Mohammed, Afzal" , kernel@pengutronix.de Ah, sorry. Forgot to answer this. On Wed, Feb 27, 2013 at 05:45:31PM +0200, Tomi Valkeinen wrote: > Ping. > > On 2013-02-18 16:09, Tomi Valkeinen wrote: > > Hi Steffen, > > > > On 2013-01-25 11:01, Steffen Trumtrar wrote: > > > >> +/* VESA display monitor timing parameters */ > >> +#define VESA_DMT_HSYNC_LOW BIT(0) > >> +#define VESA_DMT_HSYNC_HIGH BIT(1) > >> +#define VESA_DMT_VSYNC_LOW BIT(2) > >> +#define VESA_DMT_VSYNC_HIGH BIT(3) > >> + > >> +/* display specific flags */ > >> +#define DISPLAY_FLAGS_DE_LOW BIT(0) /* data enable flag */ > >> +#define DISPLAY_FLAGS_DE_HIGH BIT(1) > >> +#define DISPLAY_FLAGS_PIXDATA_POSEDGE BIT(2) /* drive data on pos. edge */ > >> +#define DISPLAY_FLAGS_PIXDATA_NEGEDGE BIT(3) /* drive data on neg. edge */ > >> +#define DISPLAY_FLAGS_INTERLACED BIT(4) > >> +#define DISPLAY_FLAGS_DOUBLESCAN BIT(5) > > > > > > > >> + unsigned int dmt_flags; /* VESA DMT flags */ > >> + unsigned int data_flags; /* video data flags */ > > > > Why did you go for this approach? To be able to represent > > true/false/not-specified? > > We decided somewhere between v3 and v8 (I think), that those flags can be high/low/ignored. > > Would it be simpler to just have "flags" field? What does it give us to > > have those two separately? > > I decided to split them, so it is clear that some flags are VESA defined and the others are "invented" for the display-timings framework and may be extended. > > Should the above say raising edge/falling edge instead of positive > > edge/negative edge? > > Hm, I used posedge/negedge because it is shorter (and because of my Verilog past pretty natural to me :-) ). I don't know what others are thinking though. Regards, Steffen -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |