Re: [RFC PATCH 1/2] drm: add support for for clk and de polarity
From: Philipp Zabel <p.zabel@pengutronix.de>
Date: 2015-11-25 17:22:34
Also in:
dri-devel, linux-api, lkml
From: Philipp Zabel <p.zabel@pengutronix.de>
Date: 2015-11-25 17:22:34
Also in:
dri-devel, linux-api, lkml
Am Mittwoch, den 15.07.2015, 17:50 +0200 schrieb Manfred Schlaegl:
To get full support for parallel and LVDS displays with drm: Add representation for clock and data enable polarity in drm_display_mode flags (similar to HSYNC/VSYNC polarity) and update conversion functions from/to videomode accordingly. This is especially important for embedded devices where parallel(RGB) and LVDS displays are still widely used and drm already plays an important role. Tested on Freescale i.MX53(parallel) and i.MX6(LVDS). Background: There was the ability to set polarity of clock and data enable signals in devicetree(display-timing), struct display_timing and struct videomode, but there was no representation for this in struct drm_display_mode. Example on Freescale i.MX53/i.MX6 SoC's: * A parallel display using different clock polarity is set up using display-timing in devicetree * ipuv3 parallel outputs clock with wrong polarity Signed-off-by: Manfred Schlaegl <redacted>
Any comments on whether data enable and pixel clock polarity flags can be added to the visible DRM_MODE_FLAGs, and if not, where else this information should be kept? struct drm_display_info? This patch and the following IPUv3 patch are useful and necessary for quite some panels connected to i.MX SoCs, but adding DRM_MODE_FLAGs is somewhat out of my jurisdiction. best regards Philipp