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authorMaxime Ripard <mripard@kernel.org>2024-05-27 15:58:00 +0200
committerMaxime Ripard <mripard@kernel.org>2024-05-28 10:12:26 +0200
commitf035f4097f1e0a35a457b72427bb0c06ca0c81c4 (patch)
tree35db77a98a22b6080b608be1646af32b4e269828 /drivers/gpu/drm/display/drm_hdmi_state_helper.c
parentabb6f74973e20956d42e8227dde6fb4e92502c14 (diff)
drm/connector: hdmi: Calculate TMDS character rate
Most HDMI drivers have some code to calculate the TMDS character rate, usually to adjust an internal clock to match what the mode requires. Since the TMDS character rates mostly depends on the resolution, whether we need to repeat pixels or not, the bpc count and the format, we can now derive it from the HDMI connector state that stores all those infos and remove the duplication from drivers. Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> Link: https://patchwork.freedesktop.org/patch/msgid/20240527-kms-hdmi-connector-state-v15-11-c5af16c3aae2@kernel.org Signed-off-by: Maxime Ripard <mripard@kernel.org>
Diffstat (limited to 'drivers/gpu/drm/display/drm_hdmi_state_helper.c')
-rw-r--r--drivers/gpu/drm/display/drm_hdmi_state_helper.c67
1 files changed, 67 insertions, 0 deletions
diff --git a/drivers/gpu/drm/display/drm_hdmi_state_helper.c b/drivers/gpu/drm/display/drm_hdmi_state_helper.c
index f6cd0612ea2c..08630561d864 100644
--- a/drivers/gpu/drm/display/drm_hdmi_state_helper.c
+++ b/drivers/gpu/drm/display/drm_hdmi_state_helper.c
@@ -3,6 +3,7 @@
#include <drm/drm_atomic.h>
#include <drm/drm_connector.h>
+#include <drm/display/drm_hdmi_helper.h>
#include <drm/display/drm_hdmi_state_helper.h>
/**
@@ -25,6 +26,63 @@ void __drm_atomic_helper_connector_hdmi_reset(struct drm_connector *connector,
}
EXPORT_SYMBOL(__drm_atomic_helper_connector_hdmi_reset);
+static const struct drm_display_mode *
+connector_state_get_mode(const struct drm_connector_state *conn_state)
+{
+ struct drm_atomic_state *state;
+ struct drm_crtc_state *crtc_state;
+ struct drm_crtc *crtc;
+
+ state = conn_state->state;
+ if (!state)
+ return NULL;
+
+ crtc = conn_state->crtc;
+ if (!crtc)
+ return NULL;
+
+ crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
+ if (!crtc_state)
+ return NULL;
+
+ return &crtc_state->mode;
+}
+
+static enum drm_mode_status
+hdmi_clock_valid(const struct drm_connector *connector,
+ const struct drm_display_mode *mode,
+ unsigned long long clock)
+{
+ const struct drm_display_info *info = &connector->display_info;
+
+ if (info->max_tmds_clock && clock > info->max_tmds_clock * 1000)
+ return MODE_CLOCK_HIGH;
+
+ return MODE_OK;
+}
+
+static int
+hdmi_compute_clock(const struct drm_connector *connector,
+ struct drm_connector_state *conn_state,
+ const struct drm_display_mode *mode,
+ unsigned int bpc, enum hdmi_colorspace fmt)
+{
+ enum drm_mode_status status;
+ unsigned long long clock;
+
+ clock = drm_hdmi_compute_mode_clock(mode, bpc, fmt);
+ if (!clock)
+ return -EINVAL;
+
+ status = hdmi_clock_valid(connector, mode, clock);
+ if (status != MODE_OK)
+ return -EINVAL;
+
+ conn_state->hdmi.tmds_char_rate = clock;
+
+ return 0;
+}
+
/**
* drm_atomic_helper_connector_hdmi_check() - Helper to check HDMI connector atomic state
* @connector: DRM Connector
@@ -44,6 +102,15 @@ int drm_atomic_helper_connector_hdmi_check(struct drm_connector *connector,
drm_atomic_get_old_connector_state(state, connector);
struct drm_connector_state *new_conn_state =
drm_atomic_get_new_connector_state(state, connector);
+ const struct drm_display_mode *mode =
+ connector_state_get_mode(new_conn_state);
+ int ret;
+
+ ret = hdmi_compute_clock(connector, new_conn_state, mode,
+ new_conn_state->hdmi.output_bpc,
+ new_conn_state->hdmi.output_format);
+ if (ret)
+ return ret;
if (old_conn_state->hdmi.output_bpc != new_conn_state->hdmi.output_bpc ||
old_conn_state->hdmi.output_format != new_conn_state->hdmi.output_format) {