Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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>
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drivers/gpu/drm/display/drm_hdmi_state_helper.c
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drivers/gpu/drm/display/drm_hdmi_state_helper.c
···
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#include <drm/drm_atomic.h>
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#include <drm/drm_connector.h>
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#include <drm/display/drm_hdmi_helper.h>
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#include <drm/display/drm_hdmi_state_helper.h>
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/**
···
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}
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EXPORT_SYMBOL(__drm_atomic_helper_connector_hdmi_reset);
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static const struct drm_display_mode *
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connector_state_get_mode(const struct drm_connector_state *conn_state)
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{
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struct drm_atomic_state *state;
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struct drm_crtc_state *crtc_state;
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struct drm_crtc *crtc;
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state = conn_state->state;
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if (!state)
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return NULL;
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crtc = conn_state->crtc;
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if (!crtc)
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return NULL;
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crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
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if (!crtc_state)
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return NULL;
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return &crtc_state->mode;
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}
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static enum drm_mode_status
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hdmi_clock_valid(const struct drm_connector *connector,
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const struct drm_display_mode *mode,
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unsigned long long clock)
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{
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const struct drm_display_info *info = &connector->display_info;
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if (info->max_tmds_clock && clock > info->max_tmds_clock * 1000)
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return MODE_CLOCK_HIGH;
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return MODE_OK;
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}
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static int
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hdmi_compute_clock(const struct drm_connector *connector,
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struct drm_connector_state *conn_state,
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const struct drm_display_mode *mode,
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unsigned int bpc, enum hdmi_colorspace fmt)
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{
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enum drm_mode_status status;
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unsigned long long clock;
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clock = drm_hdmi_compute_mode_clock(mode, bpc, fmt);
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if (!clock)
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return -EINVAL;
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status = hdmi_clock_valid(connector, mode, clock);
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if (status != MODE_OK)
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return -EINVAL;
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conn_state->hdmi.tmds_char_rate = clock;
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return 0;
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}
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/**
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* drm_atomic_helper_connector_hdmi_check() - Helper to check HDMI connector atomic state
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* @connector: DRM Connector
···
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drm_atomic_get_old_connector_state(state, connector);
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struct drm_connector_state *new_conn_state =
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drm_atomic_get_new_connector_state(state, connector);
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const struct drm_display_mode *mode =
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connector_state_get_mode(new_conn_state);
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int ret;
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ret = hdmi_compute_clock(connector, new_conn_state, mode,
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new_conn_state->hdmi.output_bpc,
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new_conn_state->hdmi.output_format);
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if (ret)
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return ret;
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if (old_conn_state->hdmi.output_bpc != new_conn_state->hdmi.output_bpc ||
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old_conn_state->hdmi.output_format != new_conn_state->hdmi.output_format) {
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drivers/gpu/drm/drm_atomic.c
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drivers/gpu/drm/drm_atomic.c
···
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drm_printf(p, "\toutput_bpc=%u\n", state->hdmi.output_bpc);
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drm_printf(p, "\toutput_format=%s\n",
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drm_hdmi_connector_get_output_format_name(state->hdmi.output_format));
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drm_printf(p, "\ttmds_char_rate=%llu\n", state->hdmi.tmds_char_rate);
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}
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if (connector->connector_type == DRM_MODE_CONNECTOR_WRITEBACK)
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drivers/gpu/drm/tests/drm_hdmi_state_helper_test.c
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drivers/gpu/drm/tests/drm_hdmi_state_helper_test.c
···
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conn_state = drm_atomic_get_connector_state(state, connector);
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KUNIT_ASSERT_NOT_ERR_OR_NULL(test, conn_state);
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conn_state->hdmi.output_bpc = connector->max_bpc;
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conn_state->hdmi.output_format = HDMI_COLORSPACE_RGB;
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ret = drm_atomic_set_crtc_for_connector(conn_state, crtc);
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KUNIT_EXPECT_EQ(test, ret, 0);
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+5
include/drm/drm_connector.h
+5
include/drm/drm_connector.h