[PATCH 08/14] drm/amd/display: Add ability for HWSS to prepare the DDC before use

["Timur Kristóf" <timur.kristof@gmail.com>]

Make it possible to add a HWSS function to prepare the DDC
before trying to use it. This is going to be necessary for
external DP bridge encoders.

This commit just adds the function to common DC code.
The actual implementation of this function for DCE is
done in a subsequent commit.

Signed-off-by: Timur Kristóf <timur.kristof@gmail.com>
---
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c | 3 +++
 drivers/gpu/drm/amd/display/dc/hwss/hw_sequencer.h        | 1 +
 drivers/gpu/drm/amd/display/dc/link/link_detection.c      | 3 +++
 3 files changed, 7 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
index 1f41d6540b83..3b8b7a4d9dd8 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
@@ -1016,6 +1016,9 @@ enum dc_edid_status dm_helpers_read_local_edid(
 	else
 		ddc = &aconnector->i2c->base;
 
+	if (link->dc->hwss.prepare_ddc)
+		link->dc->hwss.prepare_ddc(link);
+
 	/* some dongles read edid incorrectly the first time,
 	 * do check sum and retry to make sure read correct edid.
 	 */
diff --git a/drivers/gpu/drm/amd/display/dc/hwss/hw_sequencer.h b/drivers/gpu/drm/amd/display/dc/hwss/hw_sequencer.h
index 5c9a758fde37..93e171c3a179 100644
--- a/drivers/gpu/drm/amd/display/dc/hwss/hw_sequencer.h
+++ b/drivers/gpu/drm/amd/display/dc/hwss/hw_sequencer.h
@@ -1188,6 +1188,7 @@ struct hw_sequencer_funcs {
 			const struct link_resource *link_res,
 			enum signal_type signal);
 	bool (*dac_load_detect)(struct dc_link *link);
+	void (*prepare_ddc)(struct dc_link *link);
 
 	void (*get_dcc_en_bits)(struct dc *dc, int *dcc_en_bits);
 
diff --git a/drivers/gpu/drm/amd/display/dc/link/link_detection.c b/drivers/gpu/drm/amd/display/dc/link/link_detection.c
index e1d568905581..2ccbca570c77 100644
--- a/drivers/gpu/drm/amd/display/dc/link/link_detection.c
+++ b/drivers/gpu/drm/amd/display/dc/link/link_detection.c
@@ -909,6 +909,9 @@ static bool link_detect_ddc_probe(struct dc_link *link)
 	if (!link->ddc)
 		return false;
 
+	if (link->dc->hwss.prepare_ddc)
+		link->dc->hwss.prepare_ddc(link);
+
 	set_ddc_transaction_type(link->ddc, transaction_type);
 
 	uint8_t edid_header[8] = {0};
-- 
2.52.0