[PATCH 16/18] drm/i915/sdvo: Read out HDMI infoframes

[Ville Syrjala]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

Read the HDMI infoframes from the hbuf and unpack them into
the crtc state.

Well, actually just AVI infoframe for now but let's write the
infoframe readout code in a more generic fashion in case we
expand this later.

Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/intel_sdvo.c | 92 +++++++++++++++++++++++++++++++++++++--
 1 file changed, 89 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_sdvo.c b/drivers/gpu/drm/i915/intel_sdvo.c
index d8c78aebaf01..4d787c86df6d 100644
--- a/drivers/gpu/drm/i915/intel_sdvo.c
+++ b/drivers/gpu/drm/i915/intel_sdvo.c
@@ -981,6 +981,58 @@ static bool intel_sdvo_write_infoframe(struct intel_sdvo *intel_sdvo,
 				    &tx_rate, 1);
 }
 
+static ssize_t intel_sdvo_read_infoframe(struct intel_sdvo *intel_sdvo,
+					 unsigned int if_index,
+					 u8 *data, unsigned int length)
+{
+	u8 set_buf_index[2] = { if_index, 0 };
+	u8 hbuf_size, tx_rate, av_split;
+	int i;
+
+	if (!intel_sdvo_get_value(intel_sdvo,
+				  SDVO_CMD_GET_HBUF_AV_SPLIT,
+				  &av_split, 1))
+		return -ENXIO;
+
+	if (av_split < if_index)
+		return 0;
+
+	if (!intel_sdvo_get_value(intel_sdvo,
+				  SDVO_CMD_GET_HBUF_TXRATE,
+				  &tx_rate, 1))
+		return -ENXIO;
+
+	if (tx_rate == SDVO_HBUF_TX_DISABLED)
+		return 0;
+
+	if (!intel_sdvo_set_value(intel_sdvo,
+				  SDVO_CMD_SET_HBUF_INDEX,
+				  set_buf_index, 2))
+		return -ENXIO;
+
+	if (!intel_sdvo_get_value(intel_sdvo, SDVO_CMD_GET_HBUF_INFO,
+				  &hbuf_size, 1))
+		return -ENXIO;
+
+	/* Buffer size is 0 based, hooray! */
+	hbuf_size++;
+
+	DRM_DEBUG_KMS("reading sdvo hbuf: %i, hbuf_size %i, hbuf_size: %i\n",
+		      if_index, length, hbuf_size);
+
+	hbuf_size = min_t(unsigned int, length, hbuf_size);
+
+	for (i = 0; i < hbuf_size; i += 8) {
+		if (!intel_sdvo_write_cmd(intel_sdvo, SDVO_CMD_GET_HBUF_DATA, NULL, 0))
+			return -ENXIO;
+		if (!intel_sdvo_read_response(intel_sdvo, &data[i],
+					      min_t(unsigned int, 8, hbuf_size - i)))
+			return -ENXIO;
+	}
+
+	return hbuf_size;
+}
+
 static bool intel_sdvo_compute_avi_infoframe(struct intel_sdvo *intel_sdvo,
 					     struct intel_crtc_state *crtc_state,
 					     struct drm_connector_state *conn_state)
@@ -1039,6 +1091,37 @@ static bool intel_sdvo_set_avi_infoframe(struct intel_sdvo *intel_sdvo,
 					  sdvo_data, sizeof(sdvo_data));
 }
 
+static bool intel_sdvo_get_avi_infoframe(struct intel_sdvo *intel_sdvo,
+					 struct intel_crtc_state *crtc_state)
+{
+	u8 sdvo_data[HDMI_INFOFRAME_SIZE(AVI)];
+	union hdmi_infoframe *frame = &crtc_state->infoframes.avi;
+	ssize_t len;
+	int ret;
+
+	if (!crtc_state->has_hdmi_sink)
+		return true;
+
+	len = intel_sdvo_read_infoframe(intel_sdvo, SDVO_HBUF_INDEX_AVI_IF,
+					sdvo_data, sizeof(sdvo_data));
+	if (len < 0)
+		return false;
+	else if (len == 0)
+		return true;
+
+	crtc_state->infoframes.enable |=
+		intel_hdmi_infoframe_enable(HDMI_INFOFRAME_TYPE_AVI);
+
+	ret = hdmi_infoframe_unpack(frame, sdvo_data, sizeof(sdvo_data));
+	if (ret)
+		return false;
+
+	if (frame->any.type != HDMI_INFOFRAME_TYPE_AVI)
+		return false;
+
+	return true;
+}
+
 static bool intel_sdvo_set_tv_format(struct intel_sdvo *intel_sdvo,
 				     const struct drm_connector_state *conn_state)
 {
@@ -1535,6 +1618,10 @@ static void intel_sdvo_get_config(struct intel_encoder *encoder,
 		}
 	}
 
+	WARN(encoder_pixel_multiplier != pipe_config->pixel_multiplier,
+	     "SDVO pixel multiplier mismatch, port: %i, encoder: %i\n",
+	     pipe_config->pixel_multiplier, encoder_pixel_multiplier);
+
 	if (sdvox & HDMI_COLOR_RANGE_16_235)
 		pipe_config->limited_color_range = true;
 
@@ -1547,9 +1634,8 @@ static void intel_sdvo_get_config(struct intel_encoder *encoder,
 			pipe_config->has_hdmi_sink = true;
 	}
 
-	WARN(encoder_pixel_multiplier != pipe_config->pixel_multiplier,
-	     "SDVO pixel multiplier mismatch, port: %i, encoder: %i\n",
-	     pipe_config->pixel_multiplier, encoder_pixel_multiplier);
+	if (!intel_sdvo_get_avi_infoframe(intel_sdvo, pipe_config))
+		DRM_ERROR("failed to read AVI infoframe\n");
 }
 
 static void intel_disable_sdvo(struct intel_encoder *encoder,
-- 
2.16.4