[Intel-gfx] [PATCH v3 5/6] drm/i915: enable scrambling

Sharma, Shashank shashank.sharma at intel.com
Tue Feb 21 08:02:19 UTC 2017


Thanks for the review Maarten.

My comments inline.


Regards

Shashank


On 2/20/2017 5:48 PM, Maarten Lankhorst wrote:
> Op 10-02-17 om 17:29 schreef Shashank Sharma:
>> 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.
>>
>> Signed-off-by: Shashank Sharma <shashank.sharma at intel.com>
>> ---
>>   drivers/gpu/drm/i915/i915_reg.h   |   4 ++
>>   drivers/gpu/drm/i915/intel_ddi.c  |  28 ++++++++++
>>   drivers/gpu/drm/i915/intel_drv.h  |  14 +++++
>>   drivers/gpu/drm/i915/intel_hdmi.c | 106 ++++++++++++++++++++++++++++++++++++++
>>   4 files changed, 152 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
>> index 141a5c1..81cf10b 100644
>> --- a/drivers/gpu/drm/i915/i915_reg.h
>> +++ b/drivers/gpu/drm/i915/i915_reg.h
>> @@ -7819,7 +7819,11 @@ 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)
>>   
>>   /* 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 cd6fedd..bd8293d 100644
>> --- a/drivers/gpu/drm/i915/intel_ddi.c
>> +++ b/drivers/gpu/drm/i915/intel_ddi.c
>> @@ -1278,6 +1278,11 @@ void intel_ddi_enable_transcoder_func(struct drm_crtc *crtc)
>>   			temp |= TRANS_DDI_MODE_SELECT_HDMI;
>>   		else
>>   			temp |= TRANS_DDI_MODE_SELECT_DVI;
>> +
>> +		if (IS_GEMINILAKE(dev_priv))
>> +			temp = intel_hdmi_handle_source_scrambling(
>> +				intel_encoder,
>> +				&intel_crtc->config->base.adjusted_mode, temp);
>>   	} else if (type == INTEL_OUTPUT_ANALOG) {
>>   		temp |= TRANS_DDI_MODE_SELECT_FDI;
>>   		temp |= (intel_crtc->config->fdi_lanes - 1) << 1;
>> @@ -1843,6 +1848,21 @@ static void intel_enable_ddi(struct intel_encoder *intel_encoder,
>>   		struct intel_digital_port *intel_dig_port =
>>   			enc_to_dig_port(encoder);
>>   
>> +		if (IS_GEMINILAKE(dev_priv)) {
>> +			struct intel_crtc *crtc = to_intel_crtc(encoder->crtc);
>> +			/*
>> +			 * GLK sports a native HDMI 2.0 controller. If required
>> +			 * clock rate is > 340 Mhz && scrambling is supported
>> +			 * by sink, enable scrambling before enabling the
>> +			 * HDMI 2.0 port. The sink can choose to disable the
>> +			 * scrambling if it doesn't detect a scrambled within
>> +			 * 100 ms.
>> +			 */
>> +			intel_hdmi_handle_sink_scrambling(intel_encoder,
>> +						conn_state->connector,
>> +						crtc->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.
>> @@ -1875,6 +1895,14 @@ 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) {
>> +		struct intel_crtc *intel_crtc = to_intel_crtc(encoder->crtc);
>> +
>> +		intel_hdmi_handle_sink_scrambling(intel_encoder,
>> +					old_conn_state->connector,
>> +					intel_crtc->config, false);
>> +	}
>> +
>>   	if (type == INTEL_OUTPUT_EDP) {
>>   		struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
>>   
>> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
>> index 6e37fba..df0170b88 100644
>> --- a/drivers/gpu/drm/i915/intel_drv.h
>> +++ b/drivers/gpu/drm/i915/intel_drv.h
>> @@ -691,6 +691,12 @@ struct intel_crtc_state {
>>   
>>   	/* Gamma mode programmed on the pipe */
>>   	uint32_t gamma_mode;
>> +
>> +	/* HDMI scrambling status (sink) */
>> +	bool scrambling;
>> +
>> +	/* HDMI High TMDS char rate ratio (sink) */
>> +	bool high_tmds_clock_ratio;
>>   };
> Since this is for hdmi, maybe add that to the variable name too?
Yes, we can very well do this. I will address this.
> Otherwise looks sane, I wish intel_crtc->config was gone and intel_crtc_state explicitly passed, but that won't happen just yet..
Yeah, I know, that would be cleaner. But in the current code this is 
more feasible to do, isn't it ?

- Shashank
>>   struct vlv_wm_state {
>> @@ -1609,6 +1615,14 @@ 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);
>> +uint32_t
>> +intel_hdmi_handle_source_scrambling(struct intel_encoder *intel_encoder,
>> +					struct drm_display_mode *mode,
>> +					uint32_t config);
>> +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 a580de8..9970131 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>
>> @@ -1795,6 +1796,111 @@ static void intel_hdmi_destroy(struct drm_connector *connector)
>>   	intel_hdmi->aspect_ratio = HDMI_PICTURE_ASPECT_NONE;
>>   }
>>   
>> +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_scdc *scdc = &connector->display_info.hdmi.scdc;
>> +	struct drm_scrambling *scrambling = &scdc->scrambling;
>> +	struct drm_display_mode *mode = &config->base.adjusted_mode;
>> +	struct drm_i915_private *dev_priv = connector->dev->dev_private;
>> +	struct i2c_adapter *adptr = intel_gmbus_get_adapter(dev_priv,
>> +							  intel_hdmi->ddc_bus);
>> +
>> +	if (!scrambling->supported)
>> +		return;
>> +
>> +	DRM_DEBUG_KMS("Setting sink scrambling for enc:%s connector:%s\n",
>> +			intel_encoder->base.name, connector->name);
>> +
>> +	if (enable) {
>> +
>> +		if (mode->clock > 340000) {
>> +			/* Set TMDS bit clock ratio to 1/40 */
>> +			config->high_tmds_clock_ratio =
>> +				drm_scdc_set_high_tmds_clock_ratio(adptr);
>> +			if (!config->high_tmds_clock_ratio) {
>> +				DRM_ERROR("Set high TMDS ratio failed\n");
>> +				return;
>> +			}
>> +
>> +			/* Enable sink scrambling */
>> +			config->scrambling = drm_scdc_enable_scrambling(adptr);
>> +			if (!config->scrambling) {
>> +				DRM_ERROR("Can't enable sink scrambling\n");
>> +				return;
>> +			}
>> +		}
>> +
>> +		/* Few sinks support scrambling at clocks <=340 MHz too */
>> +		if (!config->scrambling && scrambling->low_rates) {
>> +			config->scrambling = drm_scdc_enable_scrambling(adptr);
>> +			if (!config->scrambling)
>> +				DRM_ERROR("Can't enable sink scrambling\n");
>> +		}
>> +
>> +		return;
>> +	}
>> +
>> +	if (config->high_tmds_clock_ratio) {
>> +		/* Set TMDS bit clock ratio back to 1/10 */
>> +		config->high_tmds_clock_ratio =
>> +			!(drm_scdc_clear_high_tmds_clock_ratio(adptr));
>> +		if (config->high_tmds_clock_ratio)
>> +			DRM_ERROR("Reset high TMDS ratio failed\n");
>> +	}
>> +
>> +	if (config->scrambling) {
>> +		/* Disable sink scrambling */
>> +		config->scrambling = !(drm_scdc_disable_scrambling(adptr));
>> +		if (config->scrambling)
>> +			DRM_ERROR("Disable sink scrambling failed\n");
>> +	}
>> +}
>> +
>> +static inline uint32_t _intel_hdmi_set_source_scrambling(uint32_t hdmi_config)
>> +{
>> +	return hdmi_config |= (TRANS_DDI_HDMI_SCRAMBLING |
>> +			TRANS_DDI_HDMI_SCRAMBLER_RESET_FREQ |
>> +			TRANS_DDI_HDMI_SCRAMBLER_CTS_ENABLE);
>> +}
>> +
>> +uint32_t
>> +intel_hdmi_handle_source_scrambling(struct intel_encoder *intel_encoder,
>> +			struct drm_display_mode *mode, uint32_t hdmi_config)
>> +{
>> +	struct intel_hdmi *intel_hdmi = enc_to_intel_hdmi(&intel_encoder->base);
>> +	struct drm_connector *connector = &intel_hdmi->attached_connector->base;
>> +	struct drm_hdmi_info *hdmi_info = &connector->display_info.hdmi;
>> +	struct drm_scrambling *scrambling = &hdmi_info->scdc.scrambling;
>> +
>> +	DRM_DEBUG_KMS("Setting scrambling for enc:%s connector:%s\n",
>> +			intel_encoder->base.name, connector->name);
>> +
>> +	hdmi_config &= ~(TRANS_DDI_HDMI_SCRAMBLING |
>> +		TRANS_DDI_HIGH_TMDS_CHAR_RATE |
>> +		TRANS_DDI_HDMI_SCRAMBLER_RESET_FREQ |
>> +		TRANS_DDI_HDMI_SCRAMBLER_CTS_ENABLE);
>> +
>> +	if (mode->clock <= 340000) {
>> +		/* Few sinks support scrambling at rate < 340 MHz too */
>> +		if (scrambling->low_rates)
>> +			hdmi_config =
>> +				_intel_hdmi_set_source_scrambling(hdmi_config);
>> +		return hdmi_config;
>> +	}
>> +
>> +	/* Scrambling or not, if clock > 340 MHz, set high char rate */
>> +	hdmi_config |= TRANS_DDI_HIGH_TMDS_CHAR_RATE;
>> +
>> +	if (scrambling->supported)
>> +		hdmi_config = _intel_hdmi_set_source_scrambling(hdmi_config);
>> +
>> +	return hdmi_config;
>> +}
>> +
>>   static u8 intel_hdmi_ddc_pin(struct drm_i915_private *dev_priv,
>>   			     enum port port)
>>   {
>



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