From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lothar =?UTF-8?B?V2HDn21hbm4=?= Subject: Re: [PATCH 1/9] drm/panel: simple: add a macro for defining display modes in a simpler and less error prone way Date: Tue, 17 Oct 2017 14:13:37 +0200 Message-ID: <20171017141337.088ba796@karo-electronics.de> References: <1507721021-28174-1-git-send-email-LW@KARO-electronics.de> <1507721021-28174-2-git-send-email-LW@KARO-electronics.de> <20171017120818.GB684@ulmo> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Return-path: In-Reply-To: <20171017120818.GB684@ulmo> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Thierry Reding Cc: David Airlie , Mark Rutland , Rob Herring , devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, dri-devel-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: devicetree@vger.kernel.org Hi, On Tue, 17 Oct 2017 14:08:18 +0200 Thierry Reding wrote: > On Wed, Oct 11, 2017 at 01:23:33PM +0200, Lothar Waßmann wrote: > > Create a macro that eases the definition of display mode parameters by > > accecpting the parameters: > > freq, hactive, hfront-porch, hsynclen, hback-porch, > > vactive, vfront-porch, vsynclen, vback-porch, vrefresh > > that can be usually directly taken from an LCD datasheet. > > > > Put the calculations that are now open coded repeating the same > > parameters multiple times into the macro expansion. > > > > Signed-off-by: Lothar Waßmann > > --- > > drivers/gpu/drm/panel/panel-simple.c | 14 ++++++++++++++ > > 1 file changed, 14 insertions(+) > > > > diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c > > index 474fa75..dec639d 100644 > > --- a/drivers/gpu/drm/panel/panel-simple.c > > +++ b/drivers/gpu/drm/panel/panel-simple.c > > @@ -411,6 +411,20 @@ static const struct panel_desc ampire_am_480272h3tmqw_t01h = { > > .bus_format = MEDIA_BUS_FMT_RGB888_1X24, > > }; > > > > +#define SP_DISPLAY_MODE(freq, ha, hfp, hs, hbp, va, vfp, vs, vbp, vr, flgs) { \ > > + .clock = freq, \ > > + .hdisplay = ha, \ > > + .hsync_start = (ha) + (hfp), \ > > + .hsync_end = (ha) + (hfp) + (hs), \ > > + .htotal = (ha) + (hfp) + (hs) + (hbp), \ > > + .vdisplay = (va), \ > > + .vsync_start = (va) + (vfp), \ > > + .vsync_end = (va) + (vfp) + (vs), \ > > + .vtotal = (va) + (vfp) + (vs) + (vbp), \ > > + .vrefresh = vr, \ > > + .flags = flgs, \ > > + } > > I don't think this simplifies anything. It's now completely non-obvious > which parameter is which, so you actually have to go look at the macro > definition when you add a new mode to make sure you get them right. > In the original code you have to repeat the same parameters (e.g. vertical front porch (vfp)) in multiple places which is error prone. Lothar Waßmann -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html