Geminilake platform sports a native HDMI 2.0 controller, and is
capable of driving pixel-clocks upto 594Mhz. HDMI 2.0 spec
mendates scrambling for these higher clocks, for reduced RF footprint.
This patch checks if the monitor supports scrambling, and if required,
enables it during the modeset.
V2: Addressed review comments from Ville:
- Do not track scrambling status in DRM layer, track somewhere in
driver like in intel_crtc_state.
- Don't talk to monitor at such a low layer, set monitor scrambling
in intel_enable_ddi() before enabling the port.
V3: Addressed review comments from Jani
- In comments, function names, use "sink" instead of "monitor",
so that the implementation could be close to the language of
HDMI spec.
V4: Addressed review comment from Maarten
- scrambling -> hdmi_scrambling
- high_tmds_clock_ratio -> hdmi_high_tmds_clock_ratio
V5: Addressed review comments from Ville and Ander
- Do not modifiy the crtc_state after compute_config. Move all
scrambling and tmds_clock_ratio calcutations to compute_config.
- While setting scrambling for source/sink, do not check the
conditions again, just go by the crtc_state flags. This will
simplyfy the condition checks.
V6: Addressed review comments from Ville
- Do not add IS_GLK check in disable/enable function, instead add it
in compute_config, while setting state flags.
- Remove unnecessary paranthesis.
- Simplyfy handle_sink_scrambling function as suggested.
- Add readout code for scrambling status in get_ddi_config and add a
check for the same in pipe_config_compare.
V7: Addressed review comments from Ander/Ville
- No separate function for source scrambling, make it inline
- Align the last line of the macro TRANS_DDI_HDMI_SCRAMBLING_MASK
- Do not add platform check while setting source scrambling
- Use pipe_config instead of crtc->config to set sink scrambling
- To readout scrambling status, Compare with SCRAMBLING_MASK
not any of its bits
- Remove platform check in intel_pipe_config_compare while checking
scrambling status
V8: Fixed mege conflict, Addressed review comments from Ander
- Remove the desciption/comment about scrambling fom the caller, move
it to the function
- Move the IS_GLK check into scrambling function
- Fix alignment
Signed-off-by: Shashank Sharma <shashank.sharma@xxxxxxxxx>
---
drivers/gpu/drm/i915/i915_reg.h | 7 ++++
drivers/gpu/drm/i915/intel_ddi.c | 19 +++++++++++
drivers/gpu/drm/i915/intel_display.c | 3 ++
drivers/gpu/drm/i915/intel_drv.h | 10 ++++++
drivers/gpu/drm/i915/intel_hdmi.c | 62 ++++++++++++++++++++++++++++++++++++
5 files changed, 101 insertions(+)
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index cc843f9..2d50fdc 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -7830,7 +7830,14 @@ enum {
#define TRANS_DDI_EDP_INPUT_B_ONOFF (5<<12)
#define TRANS_DDI_EDP_INPUT_C_ONOFF (6<<12)
#define TRANS_DDI_DP_VC_PAYLOAD_ALLOC (1<<8)
+#define TRANS_DDI_HDMI_SCRAMBLER_CTS_ENABLE (1<<7)
+#define TRANS_DDI_HDMI_SCRAMBLER_RESET_FREQ (1<<6)
#define TRANS_DDI_BFI_ENABLE (1<<4)
+#define TRANS_DDI_HIGH_TMDS_CHAR_RATE (1<<4)
+#define TRANS_DDI_HDMI_SCRAMBLING (1<<0)
+#define TRANS_DDI_HDMI_SCRAMBLING_MASK (TRANS_DDI_HDMI_SCRAMBLER_CTS_ENABLE \
+ | TRANS_DDI_HDMI_SCRAMBLER_RESET_FREQ \
+ | TRANS_DDI_HDMI_SCRAMBLING)
/* DisplayPort Transport Control */
#define _DP_TP_CTL_A 0x64040
diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index 0467676..b3e4c4a 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -1309,6 +1309,11 @@ void intel_ddi_enable_transcoder_func(const struct intel_crtc_state *crtc_state)
temp |= TRANS_DDI_MODE_SELECT_HDMI;
else
temp |= TRANS_DDI_MODE_SELECT_DVI;
+
+ if (crtc_state->hdmi_scrambling)
+ temp |= TRANS_DDI_HDMI_SCRAMBLING_MASK;
+ if (crtc_state->hdmi_high_tmds_clock_ratio)
+ temp |= TRANS_DDI_HIGH_TMDS_CHAR_RATE;
} else if (type == INTEL_OUTPUT_ANALOG) {
temp |= TRANS_DDI_MODE_SELECT_FDI;
temp |= (crtc_state->fdi_lanes - 1) << 1;
@@ -1882,6 +1887,9 @@ static void intel_enable_ddi(struct intel_encoder *intel_encoder,
struct intel_digital_port *intel_dig_port =
enc_to_dig_port(encoder);
+ intel_hdmi_handle_sink_scrambling(intel_encoder,
+ conn_state->connector, pipe_config, true);
+
/* In HDMI/DVI mode, the port width, and swing/emphasis values
* are ignored so nothing special needs to be done besides
* enabling the port.
@@ -1914,6 +1922,11 @@ static void intel_disable_ddi(struct intel_encoder *intel_encoder,
if (old_crtc_state->has_audio)
intel_audio_codec_disable(intel_encoder);
+ if (type == INTEL_OUTPUT_HDMI) {
+ intel_hdmi_handle_sink_scrambling(intel_encoder,
+ old_conn_state->connector, old_crtc_state, false);
+ }
+
if (type == INTEL_OUTPUT_EDP) {
struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
@@ -2040,6 +2053,12 @@ void intel_ddi_get_config(struct intel_encoder *encoder,
if (intel_hdmi->infoframe_enabled(&encoder->base, pipe_config))
pipe_config->has_infoframe = true;
+
+ if ((temp & TRANS_DDI_HDMI_SCRAMBLING_MASK) ==
+ TRANS_DDI_HDMI_SCRAMBLING_MASK)
+ pipe_config->hdmi_scrambling = true;
+ if (temp & TRANS_DDI_HIGH_TMDS_CHAR_RATE)
+ pipe_config->hdmi_high_tmds_clock_ratio = true;
/* fall through */
case TRANS_DDI_MODE_SELECT_DVI:
pipe_config->lane_count = 4;
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index e77ca7d..fb5e670 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -11701,6 +11701,9 @@ static void __printf(3, 4)
if ((INTEL_GEN(dev_priv) < 8 && !IS_HASWELL(dev_priv)) ||
IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
PIPE_CONF_CHECK_I(limited_color_range);
+
+ PIPE_CONF_CHECK_I(hdmi_scrambling);
+ PIPE_CONF_CHECK_I(hdmi_high_tmds_clock_ratio);
PIPE_CONF_CHECK_I(has_infoframe);
PIPE_CONF_CHECK_I(has_audio);
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 3af20c1..50d680c 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -729,6 +729,12 @@ struct intel_crtc_state {
/* bitmask of visible planes (enum plane_id) */
u8 active_planes;
+
+ /* HDMI scrambling status */
+ bool hdmi_scrambling;
+
+ /* HDMI High TMDS char rate ratio */
+ bool hdmi_high_tmds_clock_ratio;
};
struct intel_crtc {
@@ -1623,6 +1629,10 @@ void intel_hdmi_init_connector(struct intel_digital_port *intel_dig_port,
bool intel_hdmi_compute_config(struct intel_encoder *encoder,
struct intel_crtc_state *pipe_config,
struct drm_connector_state *conn_state);
+void intel_hdmi_handle_sink_scrambling(struct intel_encoder *intel_encoder,
+ struct drm_connector *connector,
+ struct intel_crtc_state *config,
+ bool enable);
void intel_dp_dual_mode_set_tmds_output(struct intel_hdmi *hdmi, bool enable);
diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
index c2184f7..4585aa8 100644
--- a/drivers/gpu/drm/i915/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/intel_hdmi.c
@@ -34,6 +34,7 @@
#include <drm/drm_atomic_helper.h>
#include <drm/drm_crtc.h>
#include <drm/drm_edid.h>
+#include <drm/drm_scdc_helper.h>
#include "intel_drv.h"
#include <drm/i915_drm.h>
#include <drm/intel_lpe_audio.h>
@@ -1316,6 +1317,7 @@ bool intel_hdmi_compute_config(struct intel_encoder *encoder,
struct intel_hdmi *intel_hdmi = enc_to_intel_hdmi(&encoder->base);
struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
struct drm_display_mode *adjusted_mode = &pipe_config->base.adjusted_mode;
+ struct drm_scdc *scdc = &conn_state->connector->display_info.hdmi.scdc;
int clock_8bpc = pipe_config->base.adjusted_mode.crtc_clock;
int clock_12bpc = clock_8bpc * 3 / 2;
int desired_bpp;
@@ -1385,6 +1387,16 @@ bool intel_hdmi_compute_config(struct intel_encoder *encoder,
pipe_config->lane_count = 4;
+ if (scdc->scrambling.supported && IS_GEMINILAKE(dev_priv)) {
+ if (scdc->scrambling.low_rates)
+ pipe_config->hdmi_scrambling = true;
+
+ if (pipe_config->port_clock > 340000) {
+ pipe_config->hdmi_scrambling = true;
+ pipe_config->hdmi_high_tmds_clock_ratio = true;
+ }
+ }
+
return true;
}
@@ -1794,6 +1806,56 @@ static void intel_hdmi_destroy(struct drm_connector *connector)
intel_hdmi->aspect_ratio = HDMI_PICTURE_ASPECT_NONE;
}
+/*
+ * This function handles scrambling on HDMI 2.0 capable sinks.
+ * If required clock rate is > 340 Mhz && scrambling is supported by sink
+ * it enables scrambling. This should be called before enabling the HDMI
+ * 2.0 port, as the sink can choose to disable the scrambling if it doesn't
+ * detect a scrambled clock within 100 ms.
+ */
+void intel_hdmi_handle_sink_scrambling(struct intel_encoder *intel_encoder,
+ struct drm_connector *connector,
+ struct intel_crtc_state *config,
+ bool enable)
+{
+ struct intel_hdmi *intel_hdmi = enc_to_intel_hdmi(&intel_encoder->base);
+ struct drm_i915_private *dev_priv = connector->dev->dev_private;
+ struct drm_scrambling *scrambling =
+ &connector->display_info.hdmi.scdc.scrambling;
+ struct i2c_adapter *adptr = intel_gmbus_get_adapter(dev_priv,
+ intel_hdmi->ddc_bus);
+ bool ret;
+
+ if (!scrambling->supported)
+ return;
+
+ if (!IS_GEMINILAKE(dev_priv))
+ return;
