[PATCH v4 06/16] drm/i915/hdcp: HDCP stream encryption support

Ramalingam C ramalingam.c at intel.com
Fri Nov 6 07:52:07 UTC 2020


On 2020-11-06 at 10:52:03 +0530, Anshuman Gupta wrote:
> On 2020-11-05 at 21:04:03 +0530, Ramalingam C wrote:
> > On 2020-10-27 at 22:11:58 +0530, Anshuman Gupta wrote:
> > > Both HDCP_{1.x,2.x} requires to select/deselect Multistream HDCP bit
> > > in TRANS_DDI_FUNC_CTL in order to enable/disable stream HDCP
> > > encryption over DP MST Transport Link.
> > > 
> > > HDCP 1.4 stream encryption requires to validate the stream encryption
> > > status in HDCP_STATUS_{TRANSCODER,PORT} register driving that link
> > > in order to enable/disable the stream encryption.
> > > 
> > > Both of above requirement are same for all Gen with respect to
> > > B.Spec Documentation.
> > > 
> > > v2:
> > > Cosmetic changes function name, error msg print and
> > > stream typo fixes. [Uma]
> > > 
> > > Cc: Ramalingam C <ramalingam.c at intel.com>
> > > Signed-off-by: Anshuman Gupta <anshuman.gupta at intel.com>
> > > ---
> > >  drivers/gpu/drm/i915/display/intel_ddi.c      | 10 +--
> > >  drivers/gpu/drm/i915/display/intel_ddi.h      |  6 +-
> > >  .../drm/i915/display/intel_display_types.h    |  4 +
> > >  drivers/gpu/drm/i915/display/intel_dp_hdcp.c  | 80 ++++++++++++++++---
> > >  drivers/gpu/drm/i915/display/intel_hdmi.c     | 14 ++--
> > >  drivers/gpu/drm/i915/i915_reg.h               |  1 +
> > >  6 files changed, 90 insertions(+), 25 deletions(-)
> > > 
> > > diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
> > > index 9fce623e951e..779603a38cfc 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_ddi.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
> > > @@ -1948,9 +1948,9 @@ void intel_ddi_disable_transcoder_func(const struct intel_crtc_state *crtc_state
> > >  	}
> > >  }
> > >  
> > > -int intel_ddi_toggle_hdcp_signalling(struct intel_encoder *intel_encoder,
> > > -				     enum transcoder cpu_transcoder,
> > > -				     bool enable)
> > > +int intel_ddi_toggle_hdcp_bits(struct intel_encoder *intel_encoder,
> > > +			       enum transcoder cpu_transcoder,
> > > +			       bool enable, u32 hdcp_mask)
> > >  {
> > >  	struct drm_device *dev = intel_encoder->base.dev;
> > >  	struct drm_i915_private *dev_priv = to_i915(dev);
> > > @@ -1965,9 +1965,9 @@ int intel_ddi_toggle_hdcp_signalling(struct intel_encoder *intel_encoder,
> > >  
> > >  	tmp = intel_de_read(dev_priv, TRANS_DDI_FUNC_CTL(cpu_transcoder));
> > >  	if (enable)
> > > -		tmp |= TRANS_DDI_HDCP_SIGNALLING;
> > > +		tmp |= hdcp_mask;
> > >  	else
> > > -		tmp &= ~TRANS_DDI_HDCP_SIGNALLING;
> > > +		tmp &= ~hdcp_mask;
> > >  	intel_de_write(dev_priv, TRANS_DDI_FUNC_CTL(cpu_transcoder), tmp);
> > >  	intel_display_power_put(dev_priv, intel_encoder->power_domain, wakeref);
> > >  	return ret;
> > > diff --git a/drivers/gpu/drm/i915/display/intel_ddi.h b/drivers/gpu/drm/i915/display/intel_ddi.h
> > > index dcc711cfe4fe..a4dd815c0000 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_ddi.h
> > > +++ b/drivers/gpu/drm/i915/display/intel_ddi.h
> > > @@ -50,9 +50,9 @@ u32 bxt_signal_levels(struct intel_dp *intel_dp,
> > >  		      const struct intel_crtc_state *crtc_state);
> > >  u32 ddi_signal_levels(struct intel_dp *intel_dp,
> > >  		      const struct intel_crtc_state *crtc_state);
> > > -int intel_ddi_toggle_hdcp_signalling(struct intel_encoder *intel_encoder,
> > > -				     enum transcoder cpu_transcoder,
> > > -				     bool enable);
> > > +int intel_ddi_toggle_hdcp_bits(struct intel_encoder *intel_encoder,
> > > +			       enum transcoder cpu_transcoder,
> > > +			       bool enable, u32 hdcp_mask);
> > >  void icl_sanitize_encoder_pll_mapping(struct intel_encoder *encoder);
> > >  
> > >  #endif /* __INTEL_DDI_H__ */
> > > diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
> > > index c47124a679b6..59b8fc21e3e8 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> > > +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> > > @@ -339,6 +339,10 @@ struct intel_hdcp_shim {
> > >  				 enum transcoder cpu_transcoder,
> > >  				 bool enable);
> > >  
> > > +	/* Enable/Disable stream encryption on DP MST Transport Link */
> > > +	int (*stream_encryption)(struct intel_digital_port *dig_port,
> > > +				 bool enable);
> > > +
> > >  	/* Ensures the link is still protected */
> > >  	bool (*check_link)(struct intel_digital_port *dig_port,
> > >  			   struct intel_connector *connector);
> > > diff --git a/drivers/gpu/drm/i915/display/intel_dp_hdcp.c b/drivers/gpu/drm/i915/display/intel_dp_hdcp.c
> > > index 03424d20e9f7..6dcbfaffd2c5 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_dp_hdcp.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_dp_hdcp.c
> > > @@ -16,6 +16,30 @@
> > >  #include "intel_dp.h"
> > >  #include "intel_hdcp.h"
> > >  
> > > +static unsigned int transcoder_to_stream_enc_status(enum transcoder cpu_transcoder)
> > > +{
> > > +	u32 stream_enc_mask;
> > > +
> > > +	switch (cpu_transcoder) {
> > > +	case TRANSCODER_A:
> > > +		stream_enc_mask = HDCP_STATUS_STREAM_A_ENC;
> > > +		break;
> > > +	case TRANSCODER_B:
> > > +		stream_enc_mask = HDCP_STATUS_STREAM_B_ENC;
> > > +		break;
> > > +	case TRANSCODER_C:
> > > +		stream_enc_mask = HDCP_STATUS_STREAM_C_ENC;
> > > +		break;
> > > +	case TRANSCODER_D:
> > > +		stream_enc_mask = HDCP_STATUS_STREAM_D_ENC;
> > > +		break;
> > > +	default:
> > > +		stream_enc_mask = 0;
> > > +	}
> > > +
> > > +	return stream_enc_mask;
> > > +}
> > > +
> > >  static void intel_dp_hdcp_wait_for_cp_irq(struct intel_hdcp *hdcp, int timeout)
> > >  {
> > >  	long ret;
> > > @@ -622,24 +646,57 @@ static const struct intel_hdcp_shim intel_dp_hdcp_shim = {
> > >  };
> > >  
> > >  static int
> > > -intel_dp_mst_hdcp_toggle_signalling(struct intel_digital_port *dig_port,
> > > -				    enum transcoder cpu_transcoder,
> > > -				    bool enable)
> > > +intel_dp_mst_toggle_hdcp_stream_select(struct intel_digital_port *dig_port,
> > > +				       bool enable)
> > >  {
> > >  	struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
> > > +	struct intel_dp *dp = &dig_port->dp;
> > > +	struct intel_hdcp *hdcp = &dp->attached_connector->hdcp;
> > >  	int ret;
> > >  
> > > -	if (!enable)
> > > -		usleep_range(6, 60); /* Bspec says >= 6us */
> > Any reason why this is removed from disable path? Or i am missing the
> > movement?
> It is required for HDMI when disabling HDCP signalling, not for HDCP 
> stream select.
> According to B.Spec 
> "If using HDMI or DVI, wait for at least 6 microseconds after the previous step, then disable HDCP signaling in the Transcoder DDI Function Control register."
Ok.

Reviewed-by: Ramalingam C <ramalingam.c at intel.com>
> Thanks,
> Anshuman Gupta.
> > 
> > -Ram
> > > -
> > > -	ret = intel_ddi_toggle_hdcp_signalling(&dig_port->base,
> > > -					       cpu_transcoder, enable);
> > > +	ret = intel_ddi_toggle_hdcp_bits(&dig_port->base,
> > > +					 hdcp->stream_transcoder, enable,
> > > +					 TRANS_DDI_HDCP_SELECT);
> > >  	if (ret)
> > > -		drm_dbg_kms(&i915->drm, "%s HDCP signalling failed (%d)\n",
> > > -			      enable ? "Enable" : "Disable", ret);
> > > +		drm_err(&i915->drm, "%s HDCP stream select failed (%d)\n",
> > > +			enable ? "Enable" : "Disable", ret);
> > >  	return ret;
> > >  }
> > >  
> > > +static int
> > > +intel_dp_mst_hdcp_stream_encryption(struct intel_digital_port *dig_port,
> > > +				    bool enable)
> > > +{
> > > +	struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
> > > +	struct intel_dp *dp = &dig_port->dp;
> > > +	struct intel_hdcp *hdcp = &dp->attached_connector->hdcp;
> > > +	enum port port = dig_port->base.port;
> > > +	enum transcoder cpu_transcoder = hdcp->cpu_transcoder;
> > > +	u32 stream_enc_status;
> > > +	int ret;
> > > +
> > > +	ret = intel_dp_mst_toggle_hdcp_stream_select(dig_port, enable);
> > > +	if (ret)
> > > +		return ret;
> > > +
> > > +	stream_enc_status =  transcoder_to_stream_enc_status(hdcp->stream_transcoder);
> > > +	if (!stream_enc_status)
> > > +		return -EINVAL;
> > > +
> > > +	/* Wait for encryption confirmation */
> > > +	if (intel_de_wait_for_register(i915,
> > > +				       HDCP_STATUS(i915, cpu_transcoder, port),
> > > +				       stream_enc_status,
> > > +				       enable ? stream_enc_status : 0,
> > > +				       HDCP_ENCRYPT_STATUS_CHANGE_TIMEOUT_MS)) {
> > > +		drm_err(&i915->drm, "Timed out waiting for stream encryption %s\n",
> > > +			enable ? "enabled" : "disabled");
> > > +		return -ETIMEDOUT;
> > > +	}
> > > +
> > > +	return 0;
> > > +}
> > > +
> > >  static
> > >  bool intel_dp_mst_hdcp_check_link(struct intel_digital_port *dig_port,
> > >  				  struct intel_connector *connector)
> > > @@ -673,7 +730,8 @@ static const struct intel_hdcp_shim intel_dp_mst_hdcp_shim = {
> > >  	.read_ksv_ready = intel_dp_hdcp_read_ksv_ready,
> > >  	.read_ksv_fifo = intel_dp_hdcp_read_ksv_fifo,
> > >  	.read_v_prime_part = intel_dp_hdcp_read_v_prime_part,
> > > -	.toggle_signalling = intel_dp_mst_hdcp_toggle_signalling,
> > > +	.toggle_signalling = intel_dp_hdcp_toggle_signalling,
> > > +	.stream_encryption = intel_dp_mst_hdcp_stream_encryption,
> > >  	.check_link = intel_dp_mst_hdcp_check_link,
> > >  	.hdcp_capable = intel_dp_hdcp_capable,
> > >  
> > > diff --git a/drivers/gpu/drm/i915/display/intel_hdmi.c b/drivers/gpu/drm/i915/display/intel_hdmi.c
> > > index f90838bc74fb..f58469226694 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_hdmi.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_hdmi.c
> > > @@ -1495,15 +1495,16 @@ static int kbl_repositioning_enc_en_signal(struct intel_connector *connector,
> > >  		usleep_range(25, 50);
> > >  	}
> > >  
> > > -	ret = intel_ddi_toggle_hdcp_signalling(&dig_port->base, cpu_transcoder,
> > > -					       false);
> > > +	ret = intel_ddi_toggle_hdcp_bits(&dig_port->base, cpu_transcoder,
> > > +					 false, TRANS_DDI_HDCP_SIGNALLING);
> > >  	if (ret) {
> > >  		drm_err(&dev_priv->drm,
> > >  			"Disable HDCP signalling failed (%d)\n", ret);
> > >  		return ret;
> > >  	}
> > > -	ret = intel_ddi_toggle_hdcp_signalling(&dig_port->base, cpu_transcoder,
> > > -					       true);
> > > +
> > > +	ret = intel_ddi_toggle_hdcp_bits(&dig_port->base, cpu_transcoder,
> > > +					 true, TRANS_DDI_HDCP_SIGNALLING);
> > >  	if (ret) {
> > >  		drm_err(&dev_priv->drm,
> > >  			"Enable HDCP signalling failed (%d)\n", ret);
> > > @@ -1526,8 +1527,9 @@ int intel_hdmi_hdcp_toggle_signalling(struct intel_digital_port *dig_port,
> > >  	if (!enable)
> > >  		usleep_range(6, 60); /* Bspec says >= 6us */
> > >  
> > > -	ret = intel_ddi_toggle_hdcp_signalling(&dig_port->base, cpu_transcoder,
> > > -					       enable);
> > > +	ret = intel_ddi_toggle_hdcp_bits(&dig_port->base,
> > > +					 cpu_transcoder, enable,
> > > +					 TRANS_DDI_HDCP_SIGNALLING);
> > >  	if (ret) {
> > >  		drm_err(&dev_priv->drm, "%s HDCP signalling failed (%d)\n",
> > >  			enable ? "Enable" : "Disable", ret);
> > > diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> > > index 8b021f77cb1f..77461cde6549 100644
> > > --- a/drivers/gpu/drm/i915/i915_reg.h
> > > +++ b/drivers/gpu/drm/i915/i915_reg.h
> > > @@ -9982,6 +9982,7 @@ enum skl_power_gate {
> > >  #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_HDCP_SELECT		REG_BIT(5)
> > >  #define  TRANS_DDI_BFI_ENABLE		(1 << 4)
> > >  #define  TRANS_DDI_HIGH_TMDS_CHAR_RATE	(1 << 4)
> > >  #define  TRANS_DDI_HDMI_SCRAMBLING	(1 << 0)
> > > -- 
> > > 2.26.2
> > > 


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