[PATCH 01/10] drm/i915: Add automated testing support for Displayport compliance testing

[Todd Previte <tprevite@gmail.com>]

Add the skeleton framework for supporting automation for Displayport compliance
testing. This patch adds the necessary framework for the source device to appropriately
respond to test automation requests from a sink device.

Signed-off-by: Todd Previte <tprevite@gmail.com>
---
 drivers/gpu/drm/i915/intel_dp.c | 82 ++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 80 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 64c8e04..f7d4119 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -3959,11 +3959,89 @@ intel_dp_get_sink_irq_esi(struct intel_dp *intel_dp, u8 *sink_irq_vector)
 	return true;
 }
 
+/* Displayport compliance testing - Link training */
+static uint8_t
+intel_dp_autotest_link_training(struct intel_dp *intel_dp)
+{
+	uint8_t test_result = DP_TEST_NAK;
+	return test_result;
+}
+
+/* Displayport compliance testing - Video pattern testing */
+static uint8_t
+intel_dp_autotest_video_pattern(struct intel_dp *intel_dp)
+{
+	uint8_t test_result = DP_TEST_NAK;
+	return test_result;
+}
+
+/* Displayport compliance testing - EDID operations */
+static uint8_t
+intel_dp_autotest_edid(struct intel_dp *intel_dp)
+{
+	uint8_t test_result = DP_TEST_NAK;
+	return test_result;
+}
+
+/* Displayport compliance testing - PHY pattern testing */
+static uint8_t
+intel_dp_autotest_phy_pattern(struct intel_dp *intel_dp)
+{
+	uint8_t test_result = DP_TEST_NAK;
+	return test_result;
+}
+
 static void
 intel_dp_handle_test_request(struct intel_dp *intel_dp)
 {
-	/* NAK by default */
-	drm_dp_dpcd_writeb(&intel_dp->aux, DP_TEST_RESPONSE, DP_TEST_NAK);
+	uint8_t response = DP_TEST_NAK;
+	uint8_t rxdata = 0;
+	int status = 0;
+
+	DRM_DEBUG_KMS("Received automated test request\n");
+	status = drm_dp_dpcd_read(&intel_dp->aux, DP_TEST_REQUEST, &rxdata, 1);
+
+	/* ACK/NAK response based on test function response
+	   Unimplemented/unsupported tests will NAK by default */
+	switch (rxdata) {
+	case DP_TEST_LINK_TRAINING:
+		DRM_DEBUG_KMS("Executing LINK_TRAINING request\n");
+		intel_dp->compliance_test_data = DP_TEST_LINK_TRAINING;
+		response = intel_dp_autotest_link_training(intel_dp);
+		break;
+	case DP_TEST_LINK_VIDEO_PATTERN:
+		DRM_DEBUG_KMS("Executing TEST_PATTERN request\n");
+		intel_dp->compliance_test_data = DP_TEST_LINK_VIDEO_PATTERN;
+		response = intel_dp_autotest_video_pattern(intel_dp);
+		break;
+	case DP_TEST_LINK_EDID_READ:
+		DRM_DEBUG_KMS("Executing EDID request\n");
+		intel_dp->compliance_test_data = DP_TEST_LINK_EDID_READ;
+		response = intel_dp_autotest_edid(intel_dp);
+		break;
+	case DP_TEST_LINK_PHY_TEST_PATTERN:
+		DRM_DEBUG_KMS("Executing PHY_PATTERN request\n");
+		intel_dp->compliance_test_data = DP_TEST_LINK_PHY_TEST_PATTERN;
+		response = intel_dp_autotest_phy_pattern(intel_dp);
+		break;
+		/* FAUX is optional in DP 1.2*/
+	case DP_TEST_LINK_FAUX_PATTERN:
+		DRM_DEBUG_KMS("FAUX_PATTERN testing not supported\n");
+		break;
+	/* Unsupported test case or something went wrong */
+	default:
+		DRM_DEBUG_KMS("Unhandled test request\n");
+		break;
+	}
+	if (status != 0) {
+		response = DP_TEST_NAK;
+		DRM_DEBUG_KMS("Error %d processing test request\n", status);
+	}
+	status = drm_dp_dpcd_write(&intel_dp->aux,
+				   DP_TEST_RESPONSE,
+				   &response, 1);
+	intel_dp->compliance_testing_active = 0;
+
 }
 
 static int
-- 
1.9.1