[Intel-gfx] [RFC 1/7] drm/dp: get/set phy compliance pattern

Animesh Manna animesh.manna at intel.com
Fri Nov 15 15:25:43 UTC 2019


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 | 97 +++++++++++++++++++++++++++++++++
 include/drm/drm_dp_helper.h     | 34 +++++++++++-
 2 files changed, 130 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index 2c7870aef469..7d0f9986a95a 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -1371,3 +1371,100 @@ 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;
+	u8 rate, lanes;
+
+	err = drm_dp_dpcd_readb(aux, DP_DPCD_REV, &data->dp_rev);
+	if (err < 0)
+		return err;
+
+	err = drm_dp_dpcd_readb(aux, DP_TEST_LINK_RATE, &rate);
+	if (err < 0)
+		return err;
+	data->link_rate = drm_dp_bw_code_to_link_rate(rate);
+
+	err = drm_dp_dpcd_readb(aux, DP_TEST_LANE_COUNT, &lanes);
+	if (err < 0)
+		return err;
+	data->num_lanes = lanes & DP_MAX_LANE_COUNT_MASK;
+
+	if (lanes & DP_ENHANCED_FRAME_CAP)
+		data->enahanced_frame_cap = true;
+
+	err = drm_dp_dpcd_readb(aux, DP_PHY_TEST_PATTERN, &data->phy_pattern);
+	if (err < 0)
+		return err;
+
+	switch (data->phy_pattern) {
+	case DP_PHY_TEST_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_PHY_TEST_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 link_config[2];
+	u8 test_pattern;
+
+	link_config[0] = drm_dp_link_rate_to_bw_code(data->link_rate);
+	link_config[1] = data->num_lanes;
+	if (data->enahanced_frame_cap)
+		link_config[1] |= DP_LANE_COUNT_ENHANCED_FRAME_EN;
+	err = drm_dp_dpcd_write(aux, DP_LINK_BW_SET, link_config, 2);
+	if (err < 0)
+		return err;
+
+	test_pattern = data->phy_pattern;
+	if (data->dp_rev < 0x12) {
+		test_pattern = (test_pattern << 2) &
+			       DP_LINK_QUAL_PATTERN_11_MASK;
+		err = drm_dp_dpcd_writeb(aux, DP_TRAINING_PATTERN_SET,
+					 test_pattern);
+		if (err < 0)
+			return err;
+	} else {
+		for (i = 0; i < data->num_lanes; i++) {
+			err = drm_dp_dpcd_writeb(aux,
+						 DP_LINK_QUAL_LANE0_SET + i,
+						 test_pattern);
+			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 51ecb5112ef8..628e484318e4 100644
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -699,7 +699,16 @@
 # define DP_TEST_CRC_SUPPORTED		    (1 << 5)
 # define DP_TEST_COUNT_MASK		    0xf
 
-#define DP_TEST_PHY_PATTERN                 0x248
+#define DP_PHY_TEST_PATTERN                 0x248
+# define DP_PHY_TEST_PATTERN_SEL_MASK       0x7
+# define DP_PHY_TEST_PATTERN_NONE           0x0
+# define DP_PHY_TEST_PATTERN_D10_2          0x1
+# define DP_PHY_TEST_PATTERN_ERROR_COUNT    0x2
+# define DP_PHY_TEST_PATTERN_PRBS7          0x3
+# define DP_PHY_TEST_PATTERN_80BIT_CUSTOM   0x4
+# define DP_PHY_TEST_PATTERN_CP2520         0x5
+
+#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
@@ -1568,4 +1577,27 @@ 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 {
+	u8 dp_rev;
+	u8 phy_pattern;
+	u8 hbr2_reset[2];
+	u8 custom80[10];
+	u32 link_rate;
+	u32 num_lanes;
+	bool enahanced_frame_cap;
+};
+
+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



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