This patch adds the ability to override the typical display timing for a
given panel. This is useful for devices which have timing constraints
that do not apply across the entire display driver (eg: to avoid
crosstalk between panel and digitizer on certain laptops). The rules are
as follows:
- panel must not specify fixed mode (since the override mode will
either be the same as the fixed mode, or we'll be unable to
check the bounds of the overried)
- panel must specify at least one display_timing range which will be
used to ensure the override mode fits within its bounds
Changes in v2:
- Parse the full display-timings node (using the native-mode) (Rob)
Changes in v3:
- No longer parse display-timings subnode, use panel-timing (Rob)
Cc: Doug Anderson <dianders at chromium.org>
Cc: Eric Anholt <eric at anholt.net>
Cc: Heiko Stuebner <heiko at sntech.de>
Cc: Jeffy Chen <jeffy.chen at rock-chips.com>
Cc: Rob Herring <robh+dt at kernel.org>
Cc: Stéphane Marchesin <marcheu at chromium.org>
Cc: Thierry Reding <thierry.reding at gmail.com>
Cc: devicetree at vger.kernel.org
Cc: dri-devel at lists.freedesktop.org
Signed-off-by: Sean Paul <seanpaul at chromium.org>
---
drivers/gpu/drm/panel/panel-simple.c | 67 +++++++++++++++++++++++++++++++++++-
1 file changed, 66 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c
index 5591984a392b..87488392bca1 100644
--- a/drivers/gpu/drm/panel/panel-simple.c
+++ b/drivers/gpu/drm/panel/panel-simple.c
@@ -34,6 +34,7 @@
#include <drm/drm_panel.h>
#include <video/display_timing.h>
+#include <video/of_display_timing.h>
#include <video/videomode.h>
struct panel_desc {
@@ -87,6 +88,8 @@ struct panel_simple {
struct i2c_adapter *ddc;
struct gpio_desc *enable_gpio;
+
+ struct drm_display_mode override_mode;
};
static inline struct panel_simple *to_panel_simple(struct drm_panel *panel)
@@ -99,11 +102,22 @@ static int panel_simple_get_fixed_modes(struct panel_simple *panel)
struct drm_connector *connector = panel->base.connector;
struct drm_device *drm = panel->base.drm;
struct drm_display_mode *mode;
+ bool has_override = panel->override_mode.type;
unsigned int i, num = 0;
if (!panel->desc)
return 0;
+ if (has_override) {
+ mode = drm_mode_duplicate(drm, &panel->override_mode);
+ if (mode) {
+ drm_mode_probed_add(connector, mode);
+ num++;
+ } else {
+ dev_err(drm->dev, "failed to add override mode\n");
+ }
+ }
+
for (i = 0; i < panel->desc->num_timings; i++) {
const struct display_timing *dt = &panel->desc->timings[i];
struct videomode vm;
@@ -120,7 +134,7 @@ static int panel_simple_get_fixed_modes(struct panel_simple *panel)
mode->type |= DRM_MODE_TYPE_DRIVER;
- if (panel->desc->num_timings == 1)
+ if (panel->desc->num_timings == 1 && !has_override)
mode->type |= DRM_MODE_TYPE_PREFERRED;
drm_mode_probed_add(connector, mode);
@@ -291,10 +305,58 @@ static const struct drm_panel_funcs panel_simple_funcs = {
.get_timings = panel_simple_get_timings,
};
+#define PANEL_SIMPLE_BOUNDS_CHECK(to_check, bounds, field) \
+ (to_check->field.typ >= bounds->field.min && \
+ to_check->field.typ <= bounds->field.max)
+static void panel_simple_add_override_mode(struct device *dev,
+ struct panel_simple *panel,
+ const struct display_timing *ot)
+{
+ const struct panel_desc *desc = panel->desc;
+ struct videomode vm;
+ int i;
+
+ if (desc->num_modes) {
+ dev_err(dev, "Reject override mode: panel has a fixed mode\n");
+ return;
+ }
+ if (!desc->num_timings) {
+ dev_err(dev, "Reject override mode: no timings specified\n");
+ return;
+ }
+
+ for (i = 0; i < panel->desc->num_timings; i++) {
+ const struct display_timing *dt = &panel->desc->timings[i];
+
+ if (!PANEL_SIMPLE_BOUNDS_CHECK(ot, dt, hactive) ||
+ !PANEL_SIMPLE_BOUNDS_CHECK(ot, dt, hfront_porch) ||
+ !PANEL_SIMPLE_BOUNDS_CHECK(ot, dt, hback_porch) ||
+ !PANEL_SIMPLE_BOUNDS_CHECK(ot, dt, hsync_len) ||
+ !PANEL_SIMPLE_BOUNDS_CHECK(ot, dt, vactive) ||
+ !PANEL_SIMPLE_BOUNDS_CHECK(ot, dt, vfront_porch) ||
+ !PANEL_SIMPLE_BOUNDS_CHECK(ot, dt, vback_porch) ||
+ !PANEL_SIMPLE_BOUNDS_CHECK(ot, dt, vsync_len))
+ continue;
+
+ if (ot->flags != dt->flags)
+ continue;
+
+ videomode_from_timing(ot, &vm);
+ drm_display_mode_from_videomode(&vm, &panel->override_mode);
+ panel->override_mode.type |= DRM_MODE_TYPE_DRIVER |
+ DRM_MODE_TYPE_PREFERRED;
+ return;
+ }
+
+ dev_err(dev, "Reject override mode: No display_timing found\n");
+ return;
+}
+
static int panel_simple_probe(struct device *dev, const struct panel_desc *desc)
{
struct device_node *backlight, *ddc;
struct panel_simple *panel;
+ struct display_timing dt;
int err;
panel = devm_kzalloc(dev, sizeof(*panel), GFP_KERNEL);
@@ -338,6 +400,9 @@ static int panel_simple_probe(struct device *dev, const struct panel_desc *desc)
}
}
+ if (!of_get_display_timing(dev->of_node, "panel-timing", &dt))
+ panel_simple_add_override_mode(dev, panel, &dt);
+
drm_panel_init(&panel->base);
panel->base.dev = dev;
panel->base.funcs = &panel_simple_funcs;
--
2.16.0.rc1.238.g530d649a79-goog