[PATCH v1] drm/amd/display: Add Debugfs Entry to Force in SST Sequence

[Fangzhi Zuo]

It is w/a to check DP2 SST behavior on M42d box.

Signed-off-by: Fangzhi Zuo <Jerry.Zuo at amd.com>
---
 .../amd/display/amdgpu_dm/amdgpu_dm_debugfs.c | 27 +++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
index 31c05eb5c64a..9590c0acba1f 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
@@ -3237,6 +3237,30 @@ static int disable_hpd_get(void *data, u64 *val)
 DEFINE_DEBUGFS_ATTRIBUTE(disable_hpd_ops, disable_hpd_get,
 			 disable_hpd_set, "%llu\n");
 
+/*
+ * w/a to force in SST mode for M42D DP2 receiver.
+ * Example usage: echo 1 > /sys/kernel/debug/dri/0/amdgpu_dm_dp2_force_sst
+ */
+static int dp2_force_sst_set(void *data, u64 val)
+{
+	struct amdgpu_device *adev = data;
+
+	adev->dm.dc->debug.set_mst_en_for_sst = val;
+
+	return 0;
+}
+
+static int dp2_force_sst_get(void *data, u64 *val)
+{
+	struct amdgpu_device *adev = data;
+
+	*val = adev->dm.dc->debug.set_mst_en_for_sst;
+
+	return 0;
+}
+DEFINE_DEBUGFS_ATTRIBUTE(dp2_force_sst_ops, dp2_force_sst_get,
+			 dp2_force_sst_set, "%llu\n");
+
 /*
  * Sets the DC visual confirm debug option from the given string.
  * Example usage: echo 1 > /sys/kernel/debug/dri/0/amdgpu_visual_confirm
@@ -3371,4 +3395,7 @@ void dtn_debugfs_init(struct amdgpu_device *adev)
 	debugfs_create_file_unsafe("amdgpu_dm_disable_hpd", 0644, root, adev,
 				   &disable_hpd_ops);
 
+	debugfs_create_file_unsafe("amdgpu_dm_dp2_force_sst", 0644, root, adev,
+					&dp2_force_sst_ops);
+
 }
-- 
2.25.1