From f0aa08387b92e432166d7143993da2635c8821e8 Mon Sep 17 00:00:00 2001 From: Stefan Agner Date: Mon, 8 Feb 2016 11:38:14 -0800 Subject: [PATCH 1/2] drm: introduce bus_flags in drm_display_info Introduce bus_flags to specify display bus properties like signal polarities. This is useful for parallel display buses, e.g. to specify the pixel clock or data enable polarity. Suggested-by: Thierry Reding Acked-by: Philipp Zabel Acked-by: Manfred Schlaegl Acked-by: Daniel Vetter Signed-off-by: Stefan Agner --- drivers/gpu/drm/panel/panel-simple.c | 2 ++ include/drm/drm_crtc.h | 9 +++++++++ 2 files changed, 11 insertions(+) diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c index ceb20486dacf..77ae07f28b7b 100644 --- a/drivers/gpu/drm/panel/panel-simple.c +++ b/drivers/gpu/drm/panel/panel-simple.c @@ -72,6 +72,7 @@ struct panel_desc { } delay; u32 bus_format; + u32 bus_flags; }; struct panel_simple { @@ -144,6 +145,7 @@ static int panel_simple_get_fixed_modes(struct panel_simple *panel) if (panel->desc->bus_format) drm_display_info_set_bus_formats(&connector->display_info, &panel->desc->bus_format, 1); + connector->display_info.bus_flags = panel->desc->bus_flags; return num; } diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h index 4acdaf5e283d..d1559cd04e3d 100644 --- a/include/drm/drm_crtc.h +++ b/include/drm/drm_crtc.h @@ -118,6 +118,14 @@ enum subpixel_order { #define DRM_COLOR_FORMAT_RGB444 (1<<0) #define DRM_COLOR_FORMAT_YCRCB444 (1<<1) #define DRM_COLOR_FORMAT_YCRCB422 (1<<2) + +#define DRM_BUS_FLAG_DE_LOW (1<<0) +#define DRM_BUS_FLAG_DE_HIGH (1<<1) +/* drive data on pos. edge */ +#define DRM_BUS_FLAG_PIXDATA_POSEDGE (1<<2) +/* drive data on neg. edge */ +#define DRM_BUS_FLAG_PIXDATA_NEGEDGE (1<<3) + /* * Describes a given display (e.g. CRT or flat panel) and its limitations. */ @@ -139,6 +147,7 @@ struct drm_display_info { const u32 *bus_formats; unsigned int num_bus_formats; + u32 bus_flags; /* Mask of supported hdmi deep color modes */ u8 edid_hdmi_dc_modes; From 2c80661d2ea9bac9bc7ba519097745829add1871 Mon Sep 17 00:00:00 2001 From: Stefan Agner Date: Mon, 8 Feb 2016 12:50:13 -0800 Subject: [PATCH 2/2] drm/fsl-dcu: use bus_flags for pixel clock polarity The drivers current default configuration drives the pixel data on rising edge of the pixel clock. However, most display sample data on rising edge... This leads to color shift artefacts visible especially at edges. This patch changes the relevant defines to be useful and actually set the bits, and changes pixel clock polarity to drive the pixel data on falling edge by default. The patch also adds an explicit pixel clock polarity flag to the display introduced with the driver (NEC WQVGA "nec,nl4827hc19-05b") using the new bus_flags field to retain the initial behavior. Signed-off-by: Stefan Agner --- drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_crtc.c | 5 +++++ drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h | 4 ++-- drivers/gpu/drm/panel/panel-simple.c | 3 ++- 3 files changed, 9 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_crtc.c b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_crtc.c index 365809edf29a..89c0084c2814 100644 --- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_crtc.c +++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_crtc.c @@ -66,6 +66,7 @@ static void fsl_dcu_drm_crtc_mode_set_nofb(struct drm_crtc *crtc) { struct drm_device *dev = crtc->dev; struct fsl_dcu_drm_device *fsl_dev = dev->dev_private; + struct drm_connector *con = &fsl_dev->connector.base; struct drm_display_mode *mode = &crtc->state->mode; unsigned int hbp, hfp, hsw, vbp, vfp, vsw, index, pol = 0; @@ -80,6 +81,10 @@ static void fsl_dcu_drm_crtc_mode_set_nofb(struct drm_crtc *crtc) vfp = mode->vsync_start - mode->vdisplay; vsw = mode->vsync_end - mode->vsync_start; + /* INV_PXCK as default (most display sample data on rising edge) */ + if (!(con->display_info.bus_flags & DRM_BUS_FLAG_PIXDATA_POSEDGE)) + pol |= DCU_SYN_POL_INV_PXCK; + if (mode->flags & DRM_MODE_FLAG_NHSYNC) pol |= DCU_SYN_POL_INV_HS_LOW; diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h index 5bb7c261fe95..c275f900ff23 100644 --- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h +++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h @@ -47,8 +47,8 @@ #define DCU_VSYN_PARA_FP(x) (x) #define DCU_SYN_POL 0x0024 -#define DCU_SYN_POL_INV_PXCK_FALL (0 << 6) -#define DCU_SYN_POL_NEG_REMAIN (0 << 5) +#define DCU_SYN_POL_INV_PXCK BIT(6) +#define DCU_SYN_POL_NEG BIT(5) #define DCU_SYN_POL_INV_VS_LOW BIT(1) #define DCU_SYN_POL_INV_HS_LOW BIT(0) diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c index 77ae07f28b7b..b19c88f188b0 100644 --- a/drivers/gpu/drm/panel/panel-simple.c +++ b/drivers/gpu/drm/panel/panel-simple.c @@ -1053,7 +1053,8 @@ static const struct panel_desc nec_nl4827hc19_05b = { .width = 95, .height = 54, }, - .bus_format = MEDIA_BUS_FMT_RGB888_1X24 + .bus_format = MEDIA_BUS_FMT_RGB888_1X24, + .bus_flags = DRM_BUS_FLAG_PIXDATA_POSEDGE, }; static const struct display_timing okaya_rs800480t_7x0gp_timing = {