From: Darren Etheridge detheridge@ti.com
Add a fixup function that will flip the hsync priority and add a hskew value that is used to shift the tda998x to the right by a variable number of pixels depending on the mode. This works around an issue with the sync timings that tilcdc is outputing.
Signed-off-by: Darren Etheridge detheridge@ti.com Tested-by: Sebastian Hesselbarth sebastian.hesselbarth@gmail.com --- Changelog: v1->v2: - fix typo in commit line (s/workaound/workaround)
Cc: David Airlie airlied@linux.ie Cc: Darren Etheridge detheridge@ti.com Cc: Rob Clark robdclark@gmail.com Cc: Russell King rmk+kernel@arm.linux.org.uk Cc: Daniel Vetter daniel.vetter@ffwll.ch Cc: dri-devel@lists.freedesktop.org Cc: linux-kernel@vger.kernel.org --- drivers/gpu/drm/tilcdc/tilcdc_crtc.c | 7 ++++++- drivers/gpu/drm/tilcdc/tilcdc_slave.c | 27 ++++++++++++++++++++++++++- 2 files changed, 32 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/tilcdc/tilcdc_crtc.c b/drivers/gpu/drm/tilcdc/tilcdc_crtc.c index 7418dcd..6d05240 100644 --- a/drivers/gpu/drm/tilcdc/tilcdc_crtc.c +++ b/drivers/gpu/drm/tilcdc/tilcdc_crtc.c @@ -379,7 +379,12 @@ static int tilcdc_crtc_mode_set(struct drm_crtc *crtc, else tilcdc_clear(dev, LCDC_RASTER_TIMING_2_REG, LCDC_SYNC_EDGE);
- if (mode->flags & DRM_MODE_FLAG_NHSYNC) + /* + * use value from adjusted_mode here as this might have been + * changed as part of the fixup for slave encoders to solve the + * issue where tilcdc timings are not VESA compliant + */ + if (adjusted_mode->flags & DRM_MODE_FLAG_NHSYNC) tilcdc_set(dev, LCDC_RASTER_TIMING_2_REG, LCDC_INVERT_HSYNC); else tilcdc_clear(dev, LCDC_RASTER_TIMING_2_REG, LCDC_INVERT_HSYNC); diff --git a/drivers/gpu/drm/tilcdc/tilcdc_slave.c b/drivers/gpu/drm/tilcdc/tilcdc_slave.c index 0bf5999..f6e9c26 100644 --- a/drivers/gpu/drm/tilcdc/tilcdc_slave.c +++ b/drivers/gpu/drm/tilcdc/tilcdc_slave.c @@ -73,13 +73,38 @@ static void slave_encoder_prepare(struct drm_encoder *encoder) tilcdc_crtc_set_panel_info(encoder->crtc, &slave_info); }
+static bool slave_encoder_fixup(struct drm_encoder *encoder, + const struct drm_display_mode *mode, + struct drm_display_mode *adjusted_mode) +{ + /* + * tilcdc does not generate VESA-complient sync but aligns + * VS on the second edge of HS instead of first edge. + * We use adjusted_mode, to fixup sync by aligning both rising + * edges and add HSKEW offset to let the slave encoder fix it up. + */ + adjusted_mode->hskew = mode->hsync_end - mode->hsync_start; + adjusted_mode->flags |= DRM_MODE_FLAG_HSKEW; + + if (mode->flags & DRM_MODE_FLAG_NHSYNC) { + adjusted_mode->flags |= DRM_MODE_FLAG_PHSYNC; + adjusted_mode->flags &= ~DRM_MODE_FLAG_NHSYNC; + } else { + adjusted_mode->flags |= DRM_MODE_FLAG_NHSYNC; + adjusted_mode->flags &= ~DRM_MODE_FLAG_PHSYNC; + } + + return drm_i2c_encoder_mode_fixup(encoder, mode, adjusted_mode); +} + + static const struct drm_encoder_funcs slave_encoder_funcs = { .destroy = slave_encoder_destroy, };
static const struct drm_encoder_helper_funcs slave_encoder_helper_funcs = { .dpms = drm_i2c_encoder_dpms, - .mode_fixup = drm_i2c_encoder_mode_fixup, + .mode_fixup = slave_encoder_fixup, .prepare = slave_encoder_prepare, .commit = drm_i2c_encoder_commit, .mode_set = drm_i2c_encoder_mode_set,