Re: [PATCH 20/20] drm/i915: write AVI infoframes for LSPCON

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Thu, Jul 13, 2017 at 06:09:53PM +0530, Sharma, Shashank wrote:
> Regards
> 
> Shashank
> 
> 
> On 7/13/2017 5:57 PM, Ville Syrjälä wrote:
> > On Thu, Jul 13, 2017 at 11:11:53AM +0530, Sharma, Shashank wrote:
> >> Regards
> >>
> >> Shashank
> >>
> >>
> >> On 7/12/2017 10:54 PM, Ville Syrjälä wrote:
> >>> On Mon, Jul 10, 2017 at 04:48:48PM +0530, Shashank Sharma wrote:
> >>>> LSPCON chips can't pick the HDMI AVI infoframes from direct link.
> >>>> In order to pass AVI infoframes from display controller to LSPCON,
> >>>> we have to write infoframe packets into vendor specified AUX address.
> >>>>
> >>>> Also, LSPCON vendors provide AUX offsets, to inform the LSPCON
> >>>> chip that the AVI IF packets are written, so that the firmware
> >>>> can pick it up and apply.
> >>>>
> >>>> This patch adds function to write AVI infoframes for both MCA as
> >>>> well as Parade Tech LSPCON chips. These two vendors provide different
> >>>> methods for writing infoframes, so this patch contains two different
> >>>> functions, one for each.
> >>> Seems to me that we should also be checking the receiver cap for the
> >>> 444->420 conversion support, and enable it in the PROTOCOL_CONVERTER
> >>> DPCD register. Or are these LSPCON things even ignoring that part of the
> >>> spec?
> >> Yes, LSPCON just needs the YCBCR444 input, and info frames for 420, and
> >> it would take care of
> >> 444->420 conversion in FW.
> > So it snoops the AVI infoframe we write to it to figure out that it has
> > to do the 444->420 downsampling?
> Yes, that's exactly what it does.

Can you add a comment somewhere appropriate to make that clear.
Otherwise people might wonder why we're not enabling the downsampling at
all.

Does LSPCON then not even implement the PROTOCOL_CONVERTER DCPD
registers?

Can you send the spec for this stuff my way? What I have now doesn't
document any DPCD registers.

> - Shashank
> >> Also, its a part of LSPCON specs, that it has
> >> to have 420 output capability.
> >>
> >> - Shashank
> >>>> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
> >>>> Cc: Imre Deak <imre.deak@intel.com>
> >>>> Signed-off-by: Shashank Sharma <shashank.sharma@intel.com>
> >>>> ---
> >>>>    drivers/gpu/drm/i915/intel_ddi.c    |   8 ++
> >>>>    drivers/gpu/drm/i915/intel_drv.h    |   3 +
> >>>>    drivers/gpu/drm/i915/intel_lspcon.c | 174 ++++++++++++++++++++++++++++++++++++
> >>>>    3 files changed, 185 insertions(+)
> >>>>
> >>>> diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
> >>>> index f691710..944d9d5 100644
> >>>> --- a/drivers/gpu/drm/i915/intel_ddi.c
> >>>> +++ b/drivers/gpu/drm/i915/intel_ddi.c
> >>>> @@ -2068,6 +2068,14 @@ void intel_ddi_set_avi_infoframe(struct drm_encoder *encoder,
> >>>>    					   rgb_qrange_limited,
> >>>>    					   rgb_qrange_selectable);
> >>>>    
> >>>> +	if (crtc_state->lspcon_active) {
> >>>> +		struct intel_lspcon *lspcon = enc_to_intel_lspcon(encoder);
> >>>> +
> >>>> +		/* LSPCON writes infoframes via AUX */
> >>>> +		lspcon->write_infoframe(encoder, crtc_state, &frame);
> >>>> +		return;
> >>>> +	}
> >>>> +
> >>>>    	intel_write_infoframe(encoder, crtc_state, &frame);
> >>>>    }
> >>>>    
> >>>> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> >>>> index fad9a53..3e686d2 100644
> >>>> --- a/drivers/gpu/drm/i915/intel_drv.h
> >>>> +++ b/drivers/gpu/drm/i915/intel_drv.h
> >>>> @@ -1079,6 +1079,9 @@ struct intel_lspcon {
> >>>>    	/* AVI IF setup function for LSPCON */
> >>>>    	void (*set_infoframes)(struct drm_encoder *encoder,
> >>>>    				const struct intel_crtc_state *crtc_state);
> >>>> +	void (*write_infoframe)(struct drm_encoder *encoder,
> >>>> +				const struct intel_crtc_state *crtc_state,
> >>>> +				union hdmi_infoframe *frame);
> >>>>    };
> >>>>    
> >>>>    struct intel_digital_port {
> >>>> diff --git a/drivers/gpu/drm/i915/intel_lspcon.c b/drivers/gpu/drm/i915/intel_lspcon.c
> >>>> index 53ddd39..01fddf7 100644
> >>>> --- a/drivers/gpu/drm/i915/intel_lspcon.c
> >>>> +++ b/drivers/gpu/drm/i915/intel_lspcon.c
> >>>> @@ -31,6 +31,18 @@
> >>>>    #define LSPCON_VENDOR_PARADE_OUI 0x001CF8
> >>>>    #define LSPCON_VENDOR_MCA_OUI 0x0060AD
> >>>>    
> >>>> +/* AUX addresses to write AVI IF into */
> >>>> +#define LSPCON_MCA_AVI_IF_WRITE_OFFSET 0x5C0
> >>>> +#define LSPCON_MCA_AVI_IF_CTRL 0x5DF
> >>>> +#define  LSPCON_MCA_AVI_IF_KICKOFF (1 << 0)
> >>>> +#define  LSPCON_MCA_AVI_IF_HANDLED (1 << 1)
> >>>> +
> >>>> +#define LSPCON_PARADE_AVI_IF_WRITE_OFFSET 0x516
> >>>> +#define LSPCON_PARADE_AVI_IF_CTRL 0x51E
> >>>> +#define  LSPCON_PARADE_AVI_IF_KICKOFF (1 << 7)
> >>>> +#define LSPCON_PARADE_AVI_IF_STATUS 0x51F
> >>>> +#define  LSPCON_PARADE_AVI_IF_HANDLED (2 << 6)
> >>>> +
> >>>>    static struct intel_dp *lspcon_to_intel_dp(struct intel_lspcon *lspcon)
> >>>>    {
> >>>>    	struct intel_digital_port *dig_port =
> >>>> @@ -217,6 +229,167 @@ bool lspcon_ycbcr420_config(struct drm_connector *connector,
> >>>>    	return false;
> >>>>    }
> >>>>    
> >>>> +static bool _lspcon_write_infoframe_parade(struct drm_dp_aux *aux,
> >>>> +					   uint8_t *buffer, ssize_t len)
> >>>> +{
> >>>> +	u8 avi_if_ctrl;
> >>>> +	u8 avi_if_status;
> >>>> +	u8 count = 0;
> >>>> +	u8 retry = 5;
> >>>> +	u8 avi_buf[8] = {0, };
> >>>> +	uint16_t reg;
> >>>> +	ssize_t ret;
> >>>> +
> >>>> +	while (count++ < 4) {
> >>>> +
> >>>> +		do {
> >>>> +			/* Is LSPCON FW ready */
> >>>> +			reg = LSPCON_PARADE_AVI_IF_CTRL;
> >>>> +			ret = drm_dp_dpcd_read(aux, reg, &avi_if_ctrl, 1);
> >>>> +			if (ret < 0) {
> >>>> +				DRM_ERROR("DPCD read failed, add:0x%x\n", reg);
> >>>> +				return false;
> >>>> +			}
> >>>> +
> >>>> +			if (avi_if_ctrl & LSPCON_PARADE_AVI_IF_KICKOFF)
> >>>> +				break;
> >>>> +			usleep_range(100, 200);
> >>>> +		} while (--retry);
> >>>> +
> >>>> +		if (!(avi_if_ctrl & LSPCON_PARADE_AVI_IF_KICKOFF)) {
> >>>> +			DRM_ERROR("LSPCON FW not ready for infoframes\n");
> >>>> +			return false;
> >>>> +		}
> >>>> +
> >>>> +		/*
> >>>> +		 * AVI Infoframe contains 31 bytes of data:
> >>>> +		 *	HB0 to HB2   (3 bytes header)
> >>>> +		 *	PB0 to PB27 (28 bytes data)
> >>>> +		 * As per Parade spec, while sending first block (8bytes),
> >>>> +		 * byte 0 is kept for request token no, and byte1 - byte7
> >>>> +		 * contain frame data. So we have to pack frame like this:
> >>>> +		 *	first block of 8 bytes: <token> <HB0-HB2> <PB0-PB3>
> >>>> +		 *	next 3 blocks: <PB4-PB27>
> >>>> +		 */
> >>>> +		if (count)
> >>>> +			memcpy(avi_buf, buffer + count * 8 - 1, 8);
> >>>> +		else {
> >>>> +			avi_buf[0] = 1;
> >>>> +			memcpy(&avi_buf[1], buffer, 7);
> >>>> +		}
> >>>> +
> >>>> +		/* Write 8 bytes of data at a time */
> >>>> +		reg = LSPCON_PARADE_AVI_IF_WRITE_OFFSET;
> >>>> +		ret = drm_dp_dpcd_write(aux, reg, avi_buf, 8);
> >>>> +		if (ret < 0) {
> >>>> +			DRM_ERROR("DPCD write failed, add:0x%x\n", reg);
> >>>> +			return false;
> >>>> +		}
> >>>> +
> >>>> +		/*
> >>>> +		 * While sending a block of 8 byes, we need to inform block
> >>>> +		 * number to FW, by programming bits[1:0] of ctrl reg with
> >>>> +		 * block number
> >>>> +		 */
> >>>> +		avi_if_ctrl = 0x80 + count;
> >>>> +		reg = LSPCON_PARADE_AVI_IF_CTRL;
> >>>> +		ret = drm_dp_dpcd_write(aux, reg, &avi_if_ctrl, 1);
> >>>> +		if (ret < 0) {
> >>>> +			DRM_ERROR("DPCD write failed, add:0x%x\n", reg);
> >>>> +			return false;
> >>>> +		}
> >>>> +	}
> >>>> +
> >>>> +	/* Check LSPCON FW status */
> >>>> +	reg = LSPCON_PARADE_AVI_IF_STATUS;
> >>>> +	ret = drm_dp_dpcd_read(aux, reg, &avi_if_status, 1);
> >>>> +	if (ret < 0) {
> >>>> +		DRM_ERROR("DPCD write failed, address 0x%x\n", reg);
> >>>> +		return false;
> >>>> +	}
> >>>> +
> >>>> +	if (avi_if_status & LSPCON_PARADE_AVI_IF_HANDLED)
> >>>> +		DRM_DEBUG_KMS("AVI IF handled by FW\n");
> >>>> +
> >>>> +	return true;
> >>>> +}
> >>>> +
> >>>> +static bool _lspcon_write_infoframe_mca(struct drm_dp_aux *aux,
> >>>> +					uint8_t *buffer, ssize_t len)
> >>>> +{
> >>>> +	int ret;
> >>>> +	uint32_t val = 0;
> >>>> +	uint16_t reg;
> >>>> +	uint8_t *data = buffer;
> >>>> +
> >>>> +	reg = LSPCON_MCA_AVI_IF_WRITE_OFFSET;
> >>>> +	while (val < len) {
> >>>> +		ret = drm_dp_dpcd_write(aux, reg, data, 1);
> >>>> +		if (ret < 0) {
> >>>> +			DRM_ERROR("DPCD write failed, add:0x%x\n", reg);
> >>>> +			return false;
> >>>> +		}
> >>>> +		val++; reg++; data++;
> >>>> +	}
> >>>> +
> >>>> +	val = 0;
> >>>> +	reg = LSPCON_MCA_AVI_IF_CTRL;
> >>>> +	ret = drm_dp_dpcd_read(aux, reg, &val, 1);
> >>>> +	if (ret < 0) {
> >>>> +		DRM_ERROR("DPCD read failed, address 0x%x\n", reg);
> >>>> +		return false;
> >>>> +	}
> >>>> +
> >>>> +	/* Indicate LSPCON chip about infoframe, clear bit 1 and set bit 0 */
> >>>> +	val &= ~LSPCON_MCA_AVI_IF_HANDLED;
> >>>> +	val |= LSPCON_MCA_AVI_IF_KICKOFF;
> >>>> +
> >>>> +	ret = drm_dp_dpcd_write(aux, reg, &val, 1);
> >>>> +	if (ret < 0) {
> >>>> +		DRM_ERROR("DPCD read failed, address 0x%x\n", reg);
> >>>> +		return false;
> >>>> +	}
> >>>> +
> >>>> +	val = 0;
> >>>> +	ret = drm_dp_dpcd_read(aux, reg, &val, 1);
> >>>> +	if (ret < 0) {
> >>>> +		DRM_ERROR("DPCD read failed, address 0x%x\n", reg);
> >>>> +		return false;
> >>>> +	}
> >>>> +
> >>>> +	if (val == LSPCON_MCA_AVI_IF_HANDLED)
> >>>> +		DRM_DEBUG_KMS("AVI IF handled by FW\n");
> >>>> +
> >>>> +	return true;
> >>>> +}
> >>>> +
> >>>> +void lspcon_write_infoframe(struct drm_encoder *encoder,
> >>>> +				  const struct intel_crtc_state *crtc_state,
> >>>> +				  union hdmi_infoframe *frame)
> >>>> +{
> >>>> +	bool ret;
> >>>> +	ssize_t len;
> >>>> +	uint8_t buf[VIDEO_DIP_DATA_SIZE];
> >>>> +	struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
> >>>> +	struct intel_lspcon *lspcon = enc_to_intel_lspcon(encoder);
> >>>> +
> >>>> +	len = hdmi_infoframe_pack(frame, buf, sizeof(buf));
> >>>> +	if (len < 0) {
> >>>> +		DRM_ERROR("Failed to pack AVI IF\n");
> >>>> +		return;
> >>>> +	}
> >>>> +
> >>>> +	if (lspcon->vendor == LSPCON_VENDOR_MCA)
> >>>> +		ret = _lspcon_write_infoframe_mca(&intel_dp->aux, buf, len);
> >>>> +	else
> >>>> +		ret = _lspcon_write_infoframe_parade(&intel_dp->aux, buf, len);
> >>>> +
> >>>> +	if (!ret)
> >>>> +		DRM_ERROR("Failed to write AVI infoframes\n");
> >>>> +	else
> >>>> +		DRM_DEBUG_DRIVER("AVI infoframes updated successfully\n");
> >>>> +}
> >>>> +
> >>>>    void lspcon_resume(struct intel_lspcon *lspcon)
> >>>>    {
> >>>>    	enum drm_lspcon_mode expected_mode;
> >>>> @@ -282,6 +455,7 @@ bool lspcon_init(struct intel_digital_port *intel_dig_port)
> >>>>    
> >>>>    	connector->ycbcr_420_allowed = true;
> >>>>    	lspcon->set_infoframes = intel_ddi_set_avi_infoframe;
> >>>> +	lspcon->write_infoframe = lspcon_write_infoframe;
> >>>>    	drm_dp_read_desc(&dp->aux, &dp->desc, drm_dp_is_branch(dp->dpcd));
> >>>>    
> >>>>    	DRM_DEBUG_KMS("Success: LSPCON init\n");
> >>>> -- 
> >>>> 2.7.4

-- 
Ville Syrjälä
Intel OTC
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