[PATCH V3] drm/stm: Fix bus_flags handling
From: Marek Vasut <marex@denx.de>
Date: 2021-01-16 16:54:55
Also in:
dri-devel
Subsystem:
drm drivers, drm drivers and misc gpu patches, the rest · Maintainers:
David Airlie, Simona Vetter, Maarten Lankhorst, Maxime Ripard, Thomas Zimmermann, Linus Torvalds
The drm_display_mode_to_videomode() does not populate DISPLAY_FLAGS_DE_LOW
or DISPLAY_FLAGS_PIXDATA_NEGEDGE flags in struct videomode. Therefore, no
matter what polarity the next bridge or display might require, these flags
are never set, and thus the LTDC GCR_DEPOL and GCR_PCPOL bits are never set,
and the LTDC behaves as if both DISPLAY_FLAGS_PIXDATA_POSEDGE and
DISPLAY_FLAGS_DE_HIGH were always set.
The fix for this problem is taken almost verbatim from MXSFB driver. In
case there is a bridge attached to the LTDC, the bridge might have extra
polarity requirements, so extract bus_flags from the bridge and use them
for LTDC configuration. Otherwise, extract bus_flags from the connector,
which is the display.
Fixes: b759012c5fa7 ("drm/stm: Add STM32 LTDC driver")
Signed-off-by: Marek Vasut <marex@denx.de>
Signed-off-by: Yannick Fertre <redacted>
Cc: Alexandre Torgue <redacted>
Cc: Antonio Borneo <redacted>
Cc: Benjamin Gaignard <redacted>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Philippe Cornu <redacted>
Cc: Sam Ravnborg <redacted>
Cc: Vincent Abriou <redacted>
Cc: Yannick Fertre <redacted>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-stm32@st-md-mailman.stormreply.com
To: dri-devel@lists.freedesktop.org
---
V2: Check if ldev->bridge->timings is non-NULL before accessing it
V3: get bus_flags from connector (from Yannick)
- Display controller could support several connectors (not connected at
the same time). ie: stm32mp15c-DK2 board have 2 connectors (HDMI + DSI).
Driver check which connector is connected to get the bus flag.
---
drivers/gpu/drm/stm/ltdc.c | 28 ++++++++++++++++++++++++++--
drivers/gpu/drm/stm/ltdc.h | 2 ++
2 files changed, 28 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c
index 7812094f93d6..b9cd2dc114cd 100644
--- a/drivers/gpu/drm/stm/ltdc.c
+++ b/drivers/gpu/drm/stm/ltdc.c@@ -525,13 +525,25 @@ static void ltdc_crtc_mode_set_nofb(struct drm_crtc *crtc) { struct ltdc_device *ldev = crtc_to_ltdc(crtc); struct drm_device *ddev = crtc->dev; + struct drm_connector_list_iter iter; + struct drm_connector *connector; struct drm_display_mode *mode = &crtc->state->adjusted_mode; struct videomode vm; + u32 bus_flags = 0; u32 hsync, vsync, accum_hbp, accum_vbp, accum_act_w, accum_act_h; u32 total_width, total_height; u32 val; int ret; + /* Get the connector which is connected */ + drm_connector_list_iter_begin(ddev, &iter); + drm_for_each_connector_iter(connector, &iter) + if(connector->status == connector_status_connected) + break; + drm_connector_list_iter_end(&iter); + + bus_flags = connector->display_info.bus_flags; + if (!pm_runtime_active(ddev->dev)) { ret = pm_runtime_get_sync(ddev->dev); if (ret) {
@@ -567,10 +579,10 @@ static void ltdc_crtc_mode_set_nofb(struct drm_crtc *crtc) if (vm.flags & DISPLAY_FLAGS_VSYNC_HIGH) val |= GCR_VSPOL; - if (vm.flags & DISPLAY_FLAGS_DE_LOW) + if (bus_flags & DRM_BUS_FLAG_DE_LOW) val |= GCR_DEPOL; - if (vm.flags & DISPLAY_FLAGS_PIXDATA_NEGEDGE) + if (bus_flags & DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE) val |= GCR_PCPOL; reg_update_bits(ldev->regs, LTDC_GCR,
@@ -1078,6 +1090,8 @@ static const struct drm_encoder_helper_funcs ltdc_encoder_helper_funcs = { static int ltdc_encoder_init(struct drm_device *ddev, struct drm_bridge *bridge) { + struct ltdc_device *ldev = ddev->dev_private; + struct drm_connector_list_iter iter; struct drm_encoder *encoder; int ret;
@@ -1099,6 +1113,16 @@ static int ltdc_encoder_init(struct drm_device *ddev, struct drm_bridge *bridge) return -EINVAL; } + ldev->bridge = bridge; + + /* + * Get hold of the connector. This is a bit of a hack, until the bridge + * API gives us bus flags and formats. + */ + drm_connector_list_iter_begin(ddev, &iter); + ldev->connector = drm_connector_list_iter_next(&iter); + drm_connector_list_iter_end(&iter); + DRM_DEBUG_DRIVER("Bridge encoder:%d created\n", encoder->base.id); return 0;
diff --git a/drivers/gpu/drm/stm/ltdc.h b/drivers/gpu/drm/stm/ltdc.h
index f153b908c70e..d0d2c81de29a 100644
--- a/drivers/gpu/drm/stm/ltdc.h
+++ b/drivers/gpu/drm/stm/ltdc.h@@ -38,6 +38,8 @@ struct ltdc_device { u32 irq_status; struct fps_info plane_fpsi[LTDC_MAX_LAYER]; struct drm_atomic_state *suspend_state; + struct drm_bridge *bridge; + struct drm_connector *connector; }; int ltdc_load(struct drm_device *ddev);
--
2.29.2
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