[Intel-gfx] [RFC 1/6] drm/dp: get/set phy compliance pattern.

[Animesh Manna]

During phy complaince auto test mode source need to read
requested test pattern from sink through DPCD. After processing
the request source need to set the pattern. So set/get method
added in drm layer as it is DP protocol.

Signed-off-by: Animesh Manna <animesh.manna at intel.com>
---
 drivers/gpu/drm/drm_dp_helper.c | 77 +++++++++++++++++++++++++++++++++
 include/drm/drm_dp_helper.h     | 28 ++++++++++++
 2 files changed, 105 insertions(+)

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index f373798d82f6..3cb7170e55f4 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -1484,3 +1484,80 @@ int drm_dp_dsc_sink_supported_input_bpcs(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_S
 	return num_bpc;
 }
 EXPORT_SYMBOL(drm_dp_dsc_sink_supported_input_bpcs);
+
+/**
+ * drm_dp_get_phy_test_pattern() - get the requested pattern from the sink.
+ * @aux: DisplayPort AUX channel
+ * @data: DP phy compliance test parameters.
+ *
+ * Returns 0 on success or a negative error code on failure.
+ */
+int drm_dp_get_phy_test_pattern(struct drm_dp_aux *aux,
+				struct drm_dp_phy_test_params *data)
+{
+	int err;
+
+	err = drm_dp_link_probe(aux, &data->link);
+	if (err < 0)
+		return err;
+
+	err = drm_dp_dpcd_read(aux, DP_TEST_PHY_PATTERN, &data->phy_pattern, 1);
+	if (err < 0)
+		return err;
+
+	switch (data->phy_pattern) {
+	case DP_TEST_PHY_PATTERN_80BIT_CUSTOM:
+		err = drm_dp_dpcd_read(aux, DP_TEST_80BIT_CUSTOM_PATTERN_7_0,
+				       &data->custom80, 10);
+		if (err < 0)
+			return err;
+
+		break;
+	case DP_TEST_PHY_PATTERN_CP2520:
+		err = drm_dp_dpcd_read(aux, DP_TEST_HBR2_SCRAMBLER_RESET,
+				       &data->hbr2_reset, 2);
+		if (err < 0)
+			return err;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(drm_dp_get_phy_test_pattern);
+
+/**
+ * drm_dp_set_phy_test_pattern() - set the pattern to the sink.
+ * @aux: DisplayPort AUX channel
+ * @data: DP phy compliance test parameters.
+ *
+ * Returns 0 on success or a negative error code on failure.
+ */
+int drm_dp_set_phy_test_pattern(struct drm_dp_aux *aux,
+				struct drm_dp_phy_test_params *data)
+{
+	int err, i;
+	u8 test_pattern;
+
+	err = drm_dp_link_configure(aux, &data->link);
+	if (err < 0)
+		return err;
+
+	test_pattern = data->phy_pattern;
+	if (data->link.revision < 0x12) {
+		test_pattern = (test_pattern << 2) &
+			       DP_LINK_QUAL_PATTERN_11_MASK;
+		err = drm_dp_dpcd_write(aux, DP_TRAINING_PATTERN_SET,
+					&test_pattern, 1);
+		if (err < 0)
+			return err;
+	} else {
+		for (i = 0; i < data->link.num_lanes; i++) {
+			err = drm_dp_dpcd_write(aux, DP_LINK_QUAL_LANE0_SET + i,
+						&test_pattern, 1);
+			if (err < 0)
+				return err;
+		}
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(drm_dp_set_phy_test_pattern);
diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
index ed1a985745ba..77dcf5879beb 100644
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -691,6 +691,14 @@
 # define DP_TEST_COUNT_MASK		    0xf
 
 #define DP_TEST_PHY_PATTERN                 0x248
+# define DP_TEST_PHY_PATTERN_NONE           0
+# define DP_TEST_PHY_PATTERN_D10_2          1
+# define DP_TEST_PHY_PATTERN_ERROR_COUNT    2
+# define DP_TEST_PHY_PATTERN_PRBS7          3
+# define DP_TEST_PHY_PATTERN_80BIT_CUSTOM   4
+# define DP_TEST_PHY_PATTERN_CP2520         5
+
+#define DP_TEST_HBR2_SCRAMBLER_RESET        0x24A
 #define DP_TEST_80BIT_CUSTOM_PATTERN_7_0    0x250
 #define	DP_TEST_80BIT_CUSTOM_PATTERN_15_8   0x251
 #define	DP_TEST_80BIT_CUSTOM_PATTERN_23_16  0x252
@@ -1523,4 +1531,24 @@ static inline void drm_dp_cec_unset_edid(struct drm_dp_aux *aux)
 
 #endif
 
+/**
+ * struct drm_dp_phy_test_params - DP Phy Compliance parameters
+ * @link: Link information.
+ * @phy_pattern: DP Phy test pattern from DPCD 0x248 (sink)
+ * @hb2_reset: DP HBR2_COMPLIANCE_SCRAMBLER_RESET from DCPD
+ *            0x24A and 0x24B (sink)
+ * @custom80: DP Test_80BIT_CUSTOM_PATTERN from DPCDs 0x250
+ *               through 0x259.
+ */
+struct drm_dp_phy_test_params {
+	struct drm_dp_link link;
+	u8 phy_pattern;
+	u8 hbr2_reset[2];
+	u8 custom80[10];
+};
+
+int drm_dp_get_phy_test_pattern(struct drm_dp_aux *aux,
+				struct drm_dp_phy_test_params *data);
+int drm_dp_set_phy_test_pattern(struct drm_dp_aux *aux,
+				struct drm_dp_phy_test_params *data);
 #endif /* _DRM_DP_HELPER_H_ */
-- 
2.22.0