drm/dp: get/set phy compliance pattern

During phy compliance 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.

v2: As per review feedback from Manasi on RFC version,
- added dp revision as function argument in set_phy_pattern api.
- used int for link_rate and u8 for lane_count to align with existing code.

v3: As per review feedback from Harry,
- used sizeof() instead of magic number.
- corrected kernel-doc for drm_dp_phy_test_params structure.

Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Reviewed-by: Manasi Navare <manasi.d.navare@intel.com>
Signed-off-by: Animesh Manna <animesh.manna@intel.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200316103759.12867-3-animesh.manna@intel.com

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index c6fbe6e..28e59d1 100644 (file)
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -1533,3 +1533,97 @@ 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_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->enhanced_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, sizeof(data->custom80));
+               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,
+                                      sizeof(data->hbr2_reset));
+               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, u8 dp_rev)
+{
+       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->enhanced_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 (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 10ddb62..e22cf5b 100644 (file)
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -702,6 +702,15 @@
 # define DP_TEST_COUNT_MASK                0xf
 
 #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
@@ -1598,4 +1607,26 @@ 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_rate: Requested Link rate from DPCD 0x219
+ * @num_lanes: Number of lanes requested by sing through DPCD 0x220
+ * @phy_pattern: DP Phy test pattern from DPCD 0x248
+ * @hb2_reset: DP HBR2_COMPLIANCE_SCRAMBLER_RESET from DCPD 0x24A and 0x24B
+ * @custom80: DP Test_80BIT_CUSTOM_PATTERN from DPCDs 0x250 through 0x259
+ * @enhanced_frame_cap: flag for enhanced frame capability.
+ */
+struct drm_dp_phy_test_params {
+       int link_rate;
+       u8 num_lanes;
+       u8 phy_pattern;
+       u8 hbr2_reset[2];
+       u8 custom80[10];
+       bool enhanced_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, u8 dp_rev);
 #endif /* _DRM_DP_HELPER_H_ */