drm/amd/display: Add debugfs entry for reading psr state

[Why]
For upcoming PSR stupport it's useful to have debug entry
to verify psr state.

[How]
 - Enable psr dc api for Linux
 - Add psr_state file to eDP connector debugfs
usage e.g.: cat /sys/kernel/debug/dri/0/DP-1/psr_state

Signed-off-by: Roman Li <Roman.Li@amd.com>
Reviewed-by: Nicholas Kazlauskas <Nicholas.Kazlauskas@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c

@@ -969,6 +969,25 @@ static int force_yuv420_output_get(void *data, u64 *val)
 DEFINE_DEBUGFS_ATTRIBUTE(force_yuv420_output_fops, force_yuv420_output_get,
 			 force_yuv420_output_set, "%llu\n");
 
+/*
+ *  Read PSR state
+ */
+static int psr_get(void *data, u64 *val)
+{
+	struct amdgpu_dm_connector *connector = data;
+	struct dc_link *link = connector->dc_link;
+	uint32_t psr_state = 0;
+
+	dc_link_get_psr_state(link, &psr_state);
+
+	*val = psr_state;
+
+	return 0;
+}
+
+
+DEFINE_DEBUGFS_ATTRIBUTE(psr_fops, psr_get, NULL, "%llu\n");
+
 void connector_debugfs_init(struct amdgpu_dm_connector *connector)
 {
 	int i;
@@ -982,6 +1001,8 @@ void connector_debugfs_init(struct amdgpu_dm_connector *connector)
 					    dp_debugfs_entries[i].fops);
 		}
 	}
+	if (connector->base.connector_type == DRM_MODE_CONNECTOR_eDP)
+		debugfs_create_file_unsafe("psr_state", 0444, dir, connector, &psr_fops);
 
 	debugfs_create_file_unsafe("force_yuv420_output", 0644, dir, connector,
 				   &force_yuv420_output_fops);

drivers/gpu/drm/amd/display/dc/core/dc_link.c

@@ -2436,6 +2436,155 @@ bool dc_link_set_psr_allow_active(struct dc_link *link, bool allow_active, bool
 	return true;
 }
 
+bool dc_link_get_psr_state(const struct dc_link *link, uint32_t *psr_state)
+{
+	struct dc  *core_dc = link->ctx->dc;
+	struct dmcu *dmcu = core_dc->res_pool->dmcu;
+
+	if (dmcu != NULL && link->psr_feature_enabled)
+		dmcu->funcs->get_psr_state(dmcu, psr_state);
+
+	return true;
+}
+
+bool dc_link_setup_psr(struct dc_link *link,
+		const struct dc_stream_state *stream, struct psr_config *psr_config,
+		struct psr_context *psr_context)
+{
+	struct dc *core_dc;
+	struct dmcu *dmcu;
+	int i;
+	/* updateSinkPsrDpcdConfig*/
+	union dpcd_psr_configuration psr_configuration;
+
+	psr_context->controllerId = CONTROLLER_ID_UNDEFINED;
+
+	if (!link)
+		return false;
+
+	core_dc = link->ctx->dc;
+	dmcu = core_dc->res_pool->dmcu;
+
+	if (!dmcu)
+		return false;
+
+
+	memset(&psr_configuration, 0, sizeof(psr_configuration));
+
+	psr_configuration.bits.ENABLE                    = 1;
+	psr_configuration.bits.CRC_VERIFICATION          = 1;
+	psr_configuration.bits.FRAME_CAPTURE_INDICATION  =
+			psr_config->psr_frame_capture_indication_req;
+
+	/* Check for PSR v2*/
+	if (psr_config->psr_version == 0x2) {
+		/* For PSR v2 selective update.
+		 * Indicates whether sink should start capturing
+		 * immediately following active scan line,
+		 * or starting with the 2nd active scan line.
+		 */
+		psr_configuration.bits.LINE_CAPTURE_INDICATION = 0;
+		/*For PSR v2, determines whether Sink should generate
+		 * IRQ_HPD when CRC mismatch is detected.
+		 */
+		psr_configuration.bits.IRQ_HPD_WITH_CRC_ERROR    = 1;
+	}
+
+	dm_helpers_dp_write_dpcd(
+		link->ctx,
+		link,
+		368,
+		&psr_configuration.raw,
+		sizeof(psr_configuration.raw));
+
+	psr_context->channel = link->ddc->ddc_pin->hw_info.ddc_channel;
+	psr_context->transmitterId = link->link_enc->transmitter;
+	psr_context->engineId = link->link_enc->preferred_engine;
+
+	for (i = 0; i < MAX_PIPES; i++) {
+		if (core_dc->current_state->res_ctx.pipe_ctx[i].stream
+				== stream) {
+			/* dmcu -1 for all controller id values,
+			 * therefore +1 here
+			 */
+			psr_context->controllerId =
+				core_dc->current_state->res_ctx.
+				pipe_ctx[i].stream_res.tg->inst + 1;
+			break;
+		}
+	}
+
+	/* Hardcoded for now.  Can be Pcie or Uniphy (or Unknown)*/
+	psr_context->phyType = PHY_TYPE_UNIPHY;
+	/*PhyId is associated with the transmitter id*/
+	psr_context->smuPhyId = link->link_enc->transmitter;
+
+	psr_context->crtcTimingVerticalTotal = stream->timing.v_total;
+	psr_context->vsyncRateHz = div64_u64(div64_u64((stream->
+					timing.pix_clk_100hz * 100),
+					stream->timing.v_total),
+					stream->timing.h_total);
+
+	psr_context->psrSupportedDisplayConfig = true;
+	psr_context->psrExitLinkTrainingRequired =
+		psr_config->psr_exit_link_training_required;
+	psr_context->sdpTransmitLineNumDeadline =
+		psr_config->psr_sdp_transmit_line_num_deadline;
+	psr_context->psrFrameCaptureIndicationReq =
+		psr_config->psr_frame_capture_indication_req;
+
+	psr_context->skipPsrWaitForPllLock = 0; /* only = 1 in KV */
+
+	psr_context->numberOfControllers =
+			link->dc->res_pool->timing_generator_count;
+
+	psr_context->rfb_update_auto_en = true;
+
+	/* 2 frames before enter PSR. */
+	psr_context->timehyst_frames = 2;
+	/* half a frame
+	 * (units in 100 lines, i.e. a value of 1 represents 100 lines)
+	 */
+	psr_context->hyst_lines = stream->timing.v_total / 2 / 100;
+	psr_context->aux_repeats = 10;
+
+	psr_context->psr_level.u32all = 0;
+
+#if defined(CONFIG_DRM_AMD_DC_DCN1_0)
+	/*skip power down the single pipe since it blocks the cstate*/
+	if (ASICREV_IS_RAVEN(link->ctx->asic_id.hw_internal_rev))
+		psr_context->psr_level.bits.SKIP_CRTC_DISABLE = true;
+#endif
+
+	/* SMU will perform additional powerdown sequence.
+	 * For unsupported ASICs, set psr_level flag to skip PSR
+	 *  static screen notification to SMU.
+	 *  (Always set for DAL2, did not check ASIC)
+	 */
+	psr_context->allow_smu_optimizations = psr_config->allow_smu_optimizations;
+
+	/* Complete PSR entry before aborting to prevent intermittent
+	 * freezes on certain eDPs
+	 */
+	psr_context->psr_level.bits.DISABLE_PSR_ENTRY_ABORT = 1;
+
+	/* Controls additional delay after remote frame capture before
+	 * continuing power down, default = 0
+	 */
+	psr_context->frame_delay = 0;
+
+	link->psr_feature_enabled = dmcu->funcs->setup_psr(dmcu, link, psr_context);
+
+	/* psr_enabled == 0 indicates setup_psr did not succeed, but this
+	 * should not happen since firmware should be running at this point
+	 */
+	if (link->psr_feature_enabled == 0)
+		ASSERT(0);
+
+	return true;
+
+}
+
 const struct dc_link_status *dc_link_get_status(const struct dc_link *link)
 {
 	return &link->link_status;