1 files changed, 92 insertions, 0 deletions
diff --git a/drivers/gpu/drm/amd/display/dc/inc/link.h b/drivers/gpu/drm/amd/display/dc/inc/link.h
new file mode 100644
index 000000000000..3945522fb798
--- /dev/null
+++ b/drivers/gpu/drm/amd/display/dc/inc/link.h
@@ -0,0 +1,92 @@
+/*
+ * Copyright 2022 Advanced Micro Devices, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * Authors: AMD
+ *
+ */
+
+#ifndef __DC_LINK_H__
+#define __DC_LINK_H__
+
+/* FILE POLICY AND INTENDED USAGE:
+ *
+ * This header declares link functions exposed to dc. All functions must have
+ * "link_" as prefix. For example link_run_my_function. This header is strictly
+ * private in dc and should never be included in other header files. dc
+ * components should include this header in their .c files in order to access
+ * functions in link folder. This file should never include any header files in
+ * link folder. If there is a need to expose a function declared in one of
+ * header files in side link folder, you need to move the function declaration
+ * into this file and prefix it with "link_".
+ */
+#include "core_types.h"
+#include "dc_link.h"
+
+struct gpio *link_get_hpd_gpio(struct dc_bios *dcb,
+		struct graphics_object_id link_id,
+		struct gpio_service *gpio_service);
+
+struct ddc_service_init_data {
+	struct graphics_object_id id;
+	struct dc_context *ctx;
+	struct dc_link *link;
+	bool is_dpia_link;
+};
+
+struct ddc_service *link_create_ddc_service(
+		struct ddc_service_init_data *ddc_init_data);
+
+void link_destroy_ddc_service(struct ddc_service **ddc);
+
+bool link_is_in_aux_transaction_mode(struct ddc_service *ddc);
+
+bool link_query_ddc_data(
+		struct ddc_service *ddc,
+		uint32_t address,
+		uint8_t *write_buf,
+		uint32_t write_size,
+		uint8_t *read_buf,
+		uint32_t read_size);
+
+
+/* Attempt to submit an aux payload, retrying on timeouts, defers, and busy
+ * states as outlined in the DP spec.  Returns true if the request was
+ * successful.
+ *
+ * NOTE: The function requires explicit mutex on DM side in order to prevent
+ * potential race condition. DC components should call the dpcd read/write
+ * function in dm_helpers in order to access dpcd safely
+ */
+bool link_aux_transfer_with_retries_no_mutex(struct ddc_service *ddc,
+		struct aux_payload *payload);
+
+uint32_t link_get_aux_defer_delay(struct ddc_service *ddc);
+
+bool link_is_dp_128b_132b_signal(struct pipe_ctx *pipe_ctx);
+
+enum dp_link_encoding link_dp_get_encoding_format(
+		const struct dc_link_settings *link_settings);
+
+bool link_decide_link_settings(
+	struct dc_stream_state *stream,
+	struct dc_link_settings *link_setting);
+
+#endif /* __DC_LINK_HPD_H__ */