drm/i915: Read the EDP DPCD and PSR Capability

v2: reuse of just created is_edp_psr and put it at right place.
v3: move is_edp_psr above intel_edp_disable
v4: remove parentheses. Noticed by Paulo.

Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Shobhit Kumar <shobhit.kumar@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

2 files changed, 14 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 11eb697dec01..fe206a4a0f9e 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -1364,6 +1364,12 @@ static void intel_dp_get_config(struct intel_encoder *encoder,
         }
 }
 
+static bool is_edp_psr(struct intel_dp *intel_dp)
+{
+        return is_edp(intel_dp) &&
+                intel_dp->psr_dpcd[0] & DP_PSR_IS_SUPPORTED;
+}
+
 static void intel_disable_dp(struct intel_encoder *encoder)
 {
         struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base);
@@ -2277,6 +2283,13 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp)
         if (intel_dp->dpcd[DP_DPCD_REV] == 0)
                 return false; /* DPCD not present */
 
+        /* Check if the panel supports PSR */
+        memset(intel_dp->psr_dpcd, 0, sizeof(intel_dp->psr_dpcd));
+        intel_dp_aux_native_read_retry(intel_dp, DP_PSR_SUPPORT,
+                                       intel_dp->psr_dpcd,
+                                       sizeof(intel_dp->psr_dpcd));
+        if (is_edp_psr(intel_dp))
+                DRM_DEBUG_KMS("Detected EDP PSR Panel.\n");
         if (!(intel_dp->dpcd[DP_DOWNSTREAMPORT_PRESENT] &
               DP_DWN_STRM_PORT_PRESENT))
                 return true; /* native DP sink */
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 5dfc1a0f2351..d25726d5307f 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -487,6 +487,7 @@ struct intel_dp {
         uint8_t link_bw;
         uint8_t lane_count;
         uint8_t dpcd[DP_RECEIVER_CAP_SIZE];
+        uint8_t psr_dpcd[EDP_PSR_RECEIVER_CAP_SIZE];
         uint8_t downstream_ports[DP_MAX_DOWNSTREAM_PORTS];
         struct i2c_adapter adapter;
         struct i2c_algo_dp_aux_data algo;