drm/amd/display: Create new i2c resource

[Why]
I2C code did not match dc resource model and was generally
unpleasant

[How]
Move code into new svelte dce_i2c files, replacing various i2c
objects with two structs: dce_i2c_sw and dce_i2c_hw.  Fully split
sw and hw code paths.  Remove all redundant declarations.  Use
address lists to distinguish between versions.  Change dce80 code
to newer register access macros.
Signed-off-by: David Francis <David.Francis@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c

@@ -71,8 +71,6 @@
 
 #include "modules/inc/mod_freesync.h"
 
-#include "i2caux_interface.h"
-
 /* basic init/fini API */
 static int amdgpu_dm_init(struct amdgpu_device *adev);
 static void amdgpu_dm_fini(struct amdgpu_device *adev);
@@ -3610,9 +3608,9 @@ static int amdgpu_dm_i2c_xfer(struct i2c_adapter *i2c_adap,
 		cmd.payloads[i].data = msgs[i].buf;
 	}
 
-	if (dal_i2caux_submit_i2c_command(
-			ddc_service->ctx->i2caux,
-			ddc_service->ddc_pin,
+	if (dc_submit_i2c(
+			ddc_service->ctx->dc,
+			ddc_service->ddc_pin->hw_info.ddc_channel,
 			&cmd))
 		result = num;
 
@@ -3648,6 +3646,7 @@ create_i2c(struct ddc_service *ddc_service,
 	snprintf(i2c->base.name, sizeof(i2c->base.name), "AMDGPU DM i2c hw bus %d", link_index);
 	i2c_set_adapdata(&i2c->base, i2c);
 	i2c->ddc_service = ddc_service;
+	i2c->ddc_service->ddc_pin->hw_info.ddc_channel = link_index;
 
 	return i2c;
 }

drivers/gpu/drm/amd/display/dc/bios/bios_parser.c

@@ -42,7 +42,7 @@
 #include "bios_parser_interface.h"
 
 #include "bios_parser_common.h"
-/* TODO remove - only needed for default i2c speed */
+
 #include "dc.h"
 
 #define THREE_PERCENT_OF_10000 300
@@ -2671,11 +2671,9 @@ static bool i2c_read(
 
 		cmd.payloads = payloads;
 		cmd.number_of_payloads = ARRAY_SIZE(payloads);
-
-		/* TODO route this through drm i2c_adapter */
-		result = dal_i2caux_submit_i2c_command(
-				ddc->ctx->i2caux,
-				ddc,
+		result = dc_submit_i2c(
+				ddc->ctx->dc,
+				ddc->hw_info.ddc_channel,
 				&cmd);
 	}
 

drivers/gpu/drm/amd/display/dc/core/dc.c

@@ -54,6 +54,9 @@
 #include "hubp.h"
 
 #include "dc_link_dp.h"
+
+#include "dce/dce_i2c.h"
+
 #define DC_LOGGER \
 	dc->ctx->logger
 
@@ -1673,9 +1676,8 @@ bool dc_submit_i2c(
 
 	struct dc_link *link = dc->links[link_index];
 	struct ddc_service *ddc = link->ddc;
-
-	return dal_i2caux_submit_i2c_command(
-		ddc->ctx->i2caux,
+	return dce_i2c_submit_command(
+		dc->res_pool,
 		ddc->ddc_pin,
 		cmd);
 }

drivers/gpu/drm/amd/display/dc/core/dc_link.c

@@ -1530,8 +1530,8 @@ static bool i2c_write(struct pipe_ctx *pipe_ctx,
 	payload.write = true;
 	cmd.payloads = &payload;
 
-	if (dc_submit_i2c(pipe_ctx->stream->ctx->dc,
-			pipe_ctx->stream->sink->link->link_index, &cmd))
+	if (dm_helpers_submit_i2c(pipe_ctx->stream->ctx,
+			pipe_ctx->stream->sink->link, &cmd))
 		return true;
 
 	return false;

drivers/gpu/drm/amd/display/dc/dce/Makefile

@@ -28,8 +28,8 @@
 
 DCE = dce_audio.o dce_stream_encoder.o dce_link_encoder.o dce_hwseq.o \
 dce_mem_input.o dce_clock_source.o dce_scl_filters.o dce_transform.o \
-dce_clocks.o dce_opp.o dce_dmcu.o dce_abm.o dce_ipp.o dce_aux.o
-
+dce_clocks.o dce_opp.o dce_dmcu.o dce_abm.o dce_ipp.o dce_aux.o \
+dce_i2c.o dce_i2c_hw.o dce_i2c_sw.o
 
 AMD_DAL_DCE = $(addprefix $(AMDDALPATH)/dc/dce/,$(DCE))
 

drivers/gpu/drm/amd/display/dc/dce/dce_i2c.c

+/*
+ * Copyright 2018 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
+ *
+ */
+#include "dce_i2c.h"
+#include "reg_helper.h"
+
+bool dce_i2c_submit_command(
+	struct resource_pool *pool,
+	struct ddc *ddc,
+	struct i2c_command *cmd)
+{
+	struct dce_i2c_hw *dce_i2c_hw;
+	struct dce_i2c_sw *dce_i2c_sw;
+
+	if (!ddc) {
+		BREAK_TO_DEBUGGER();
+		return false;
+	}
+
+	if (!cmd) {
+		BREAK_TO_DEBUGGER();
+		return false;
+	}
+
+	/* The software engine is only available on dce8 */
+	dce_i2c_sw = dce_i2c_acquire_i2c_sw_engine(pool, ddc);
+
+	if (!dce_i2c_sw) {
+		dce_i2c_hw = acquire_i2c_hw_engine(pool, ddc);
+
+		if (!dce_i2c_hw)
+			return false;
+
+		return dce_i2c_submit_command_hw(pool, ddc, cmd, dce_i2c_hw);
+	}
+
+	return dce_i2c_submit_command_sw(pool, ddc, cmd, dce_i2c_sw);
+
+}

drivers/gpu/drm/amd/display/dc/dce/dce_i2c.h

+/*
+ * Copyright 2018 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 __DCE_I2C_H__
+#define __DCE_I2C_H__
+
+#include "inc/core_types.h"
+#include "dce_i2c_hw.h"
+#include "dce_i2c_sw.h"
+
+enum dce_i2c_transaction_status {
+	DCE_I2C_TRANSACTION_STATUS_UNKNOWN = (-1L),
+	DCE_I2C_TRANSACTION_STATUS_SUCCEEDED,
+	DCE_I2C_TRANSACTION_STATUS_FAILED_CHANNEL_BUSY,
+	DCE_I2C_TRANSACTION_STATUS_FAILED_TIMEOUT,
+	DCE_I2C_TRANSACTION_STATUS_FAILED_PROTOCOL_ERROR,
+	DCE_I2C_TRANSACTION_STATUS_FAILED_NACK,
+	DCE_I2C_TRANSACTION_STATUS_FAILED_INCOMPLETE,
+	DCE_I2C_TRANSACTION_STATUS_FAILED_OPERATION,
+	DCE_I2C_TRANSACTION_STATUS_FAILED_INVALID_OPERATION,
+	DCE_I2C_TRANSACTION_STATUS_FAILED_BUFFER_OVERFLOW,
+	DCE_I2C_TRANSACTION_STATUS_FAILED_HPD_DISCON
+};
+
+enum dce_i2c_transaction_operation {
+	DCE_I2C_TRANSACTION_READ,
+	DCE_I2C_TRANSACTION_WRITE
+};
+
+struct dce_i2c_transaction_payload {
+	enum dce_i2c_transaction_address_space address_space;
+	uint32_t address;
+	uint32_t length;
+	uint8_t *data;
+};
+
+struct dce_i2c_transaction_request {
+	enum dce_i2c_transaction_operation operation;
+	struct dce_i2c_transaction_payload payload;
+	enum dce_i2c_transaction_status status;
+};
+
+
+bool dce_i2c_submit_command(
+	struct resource_pool *pool,
+	struct ddc *ddc,
+	struct i2c_command *cmd);
+
+#endif

drivers/gpu/drm/amd/display/dc/dce/dce_i2c_hw.c

+/*
+ * Copyright 2018 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
+ *
+ */
+#include "dce_i2c.h"
+#include "dce_i2c_hw.h"
+#include "reg_helper.h"
+#include "include/gpio_service_interface.h"
+
+#define CTX \
+	dce_i2c_hw->ctx
+#define REG(reg)\
+	dce_i2c_hw->regs->reg
+
+#undef FN
+#define FN(reg_name, field_name) \
+	dce_i2c_hw->shifts->field_name, dce_i2c_hw->masks->field_name
+
+
+static inline void reset_hw_engine(struct dce_i2c_hw *dce_i2c_hw)
+{
+	REG_UPDATE_2(DC_I2C_CONTROL,
+		     DC_I2C_SW_STATUS_RESET, 1,
+		     DC_I2C_SW_STATUS_RESET, 1);
+}
+
+static bool is_hw_busy(struct dce_i2c_hw *dce_i2c_hw)
+{
+	uint32_t i2c_sw_status = 0;
+
+	REG_GET(DC_I2C_SW_STATUS, DC_I2C_SW_STATUS, &i2c_sw_status);
+	if (i2c_sw_status == DC_I2C_STATUS__DC_I2C_STATUS_IDLE)
+		return false;
+
+	reset_hw_engine(dce_i2c_hw);
+
+	REG_GET(DC_I2C_SW_STATUS, DC_I2C_SW_STATUS, &i2c_sw_status);
+	return i2c_sw_status != DC_I2C_STATUS__DC_I2C_STATUS_IDLE;
+}
+
+static void set_speed_hw_dce80(
+	struct dce_i2c_hw *dce_i2c_hw,
+	uint32_t speed)
+{
+
+	if (speed) {
+		REG_UPDATE_N(SPEED, 2,
+			     FN(DC_I2C_DDC1_SPEED, DC_I2C_DDC1_PRESCALE), dce_i2c_hw->reference_frequency / speed,
+			     FN(DC_I2C_DDC1_SPEED, DC_I2C_DDC1_THRESHOLD), 2);
+	}
+}
+static void set_speed_hw_dce100(
+	struct dce_i2c_hw *dce_i2c_hw,
+	uint32_t speed)
+{
+
+	if (speed) {
+		if (dce_i2c_hw->masks->DC_I2C_DDC1_START_STOP_TIMING_CNTL)
+			REG_UPDATE_N(SPEED, 3,
+				     FN(DC_I2C_DDC1_SPEED, DC_I2C_DDC1_PRESCALE), dce_i2c_hw->reference_frequency / speed,
+				     FN(DC_I2C_DDC1_SPEED, DC_I2C_DDC1_THRESHOLD), 2,
+				     FN(DC_I2C_DDC1_SPEED, DC_I2C_DDC1_START_STOP_TIMING_CNTL), speed > 50 ? 2:1);
+		else
+			REG_UPDATE_N(SPEED, 2,
+				     FN(DC_I2C_DDC1_SPEED, DC_I2C_DDC1_PRESCALE), dce_i2c_hw->reference_frequency / speed,
+				     FN(DC_I2C_DDC1_SPEED, DC_I2C_DDC1_THRESHOLD), 2);
+	}
+}
+bool dce_i2c_hw_engine_acquire_engine(
+	struct dce_i2c_hw *dce_i2c_hw,
+	struct ddc *ddc)
+{
+
+	enum gpio_result result;
+	uint32_t current_speed;
+
+	result = dal_ddc_open(ddc, GPIO_MODE_HARDWARE,
+		GPIO_DDC_CONFIG_TYPE_MODE_I2C);
+
+	if (result != GPIO_RESULT_OK)
+		return false;
+
+	dce_i2c_hw->ddc = ddc;
+
+
+	current_speed = dce_i2c_hw->funcs->get_speed(dce_i2c_hw);
+
+	if (current_speed)
+		dce_i2c_hw->original_speed = current_speed;
+
+	return true;
+}
+bool dce_i2c_engine_acquire_hw(
+	struct dce_i2c_hw *dce_i2c_hw,
+	struct ddc *ddc_handle)
+{
+
+	uint32_t counter = 0;
+	bool result;
+
+	do {
+		result = dce_i2c_hw_engine_acquire_engine(
+				dce_i2c_hw, ddc_handle);
+
+		if (result)
+			break;
+
+		/* i2c_engine is busy by VBios, lets wait and retry */
+
+		udelay(10);
+
+		++counter;
+	} while (counter < 2);
+
+	if (result) {
+		if (!dce_i2c_hw->funcs->setup_engine(dce_i2c_hw)) {
+			dce_i2c_hw->funcs->release_engine(dce_i2c_hw);
+			result = false;
+		}
+	}
+
+	return result;
+}
+struct dce_i2c_hw *acquire_i2c_hw_engine(
+	struct resource_pool *pool,
+	struct ddc *ddc)
+{
+
+	struct dce_i2c_hw *engine = NULL;
+
+	if (!ddc)
+		return NULL;
+
+	if (ddc->hw_info.hw_supported) {
+		enum gpio_ddc_line line = dal_ddc_get_line(ddc);
+
+		if (line < pool->pipe_count)
+			engine = pool->hw_i2cs[line];
+	}
+
+	if (!engine)
+		return NULL;
+
+
+	if (!pool->i2c_hw_buffer_in_use &&
+			dce_i2c_engine_acquire_hw(engine, ddc)) {
+		pool->i2c_hw_buffer_in_use = true;
+		return engine;
+	}
+
+
+	return NULL;
+}
+
+static bool setup_engine_hw_dce100(
+	struct dce_i2c_hw *dce_i2c_hw)
+{
+	uint32_t i2c_setup_limit = I2C_SETUP_TIME_LIMIT_DCE;
+
+	if (dce_i2c_hw->setup_limit != 0)
+		i2c_setup_limit = dce_i2c_hw->setup_limit;
+	/* Program pin select */
+	REG_UPDATE_6(DC_I2C_CONTROL,
+		     DC_I2C_GO, 0,
+		     DC_I2C_SOFT_RESET, 0,
+		     DC_I2C_SEND_RESET, 0,
+		     DC_I2C_SW_STATUS_RESET, 1,
+		     DC_I2C_TRANSACTION_COUNT, 0,
+		     DC_I2C_DDC_SELECT, dce_i2c_hw->engine_id);
+
+	/* Program time limit */
+	if (dce_i2c_hw->send_reset_length == 0) {
+		/*pre-dcn*/
+		REG_UPDATE_N(SETUP, 2,
+			     FN(DC_I2C_DDC1_SETUP, DC_I2C_DDC1_TIME_LIMIT), i2c_setup_limit,
+			     FN(DC_I2C_DDC1_SETUP, DC_I2C_DDC1_ENABLE), 1);
+	}
+	/* Program HW priority
+	 * set to High - interrupt software I2C at any time
+	 * Enable restart of SW I2C that was interrupted by HW
+	 * disable queuing of software while I2C is in use by HW
+	 */
+	REG_UPDATE_2(DC_I2C_ARBITRATION,
+		     DC_I2C_NO_QUEUED_SW_GO, 0,
+		     DC_I2C_SW_PRIORITY, DC_I2C_ARBITRATION__DC_I2C_SW_PRIORITY_NORMAL);
+
+	return true;
+}
+static bool setup_engine_hw_dce80(
+	struct dce_i2c_hw *dce_i2c_hw)
+{
+
+	/* Program pin select */
+	{
+		REG_UPDATE_6(DC_I2C_CONTROL,
+			     DC_I2C_GO, 0,
+			     DC_I2C_SOFT_RESET, 0,
+			     DC_I2C_SEND_RESET, 0,
+			     DC_I2C_SW_STATUS_RESET, 1,
+			     DC_I2C_TRANSACTION_COUNT, 0,
+			     DC_I2C_DDC_SELECT, dce_i2c_hw->engine_id);
+	}
+
+	/* Program time limit */
+	{
+		REG_UPDATE_2(SETUP,
+			     DC_I2C_DDC1_TIME_LIMIT, I2C_SETUP_TIME_LIMIT_DCE,
+			     DC_I2C_DDC1_ENABLE, 1);
+	}
+
+	/* Program HW priority
+	 * set to High - interrupt software I2C at any time
+	 * Enable restart of SW I2C that was interrupted by HW
+	 * disable queuing of software while I2C is in use by HW
+	 */
+	{
+		REG_UPDATE_2(DC_I2C_ARBITRATION,
+			     DC_I2C_NO_QUEUED_SW_GO, 0,
+			     DC_I2C_SW_PRIORITY, DC_I2C_ARBITRATION__DC_I2C_SW_PRIORITY_NORMAL);
+	}
+
+	return true;
+}
+
+
+
+static void process_channel_reply_hw_dce80(
+	struct dce_i2c_hw *dce_i2c_hw,
+	struct i2c_reply_transaction_data *reply)
+{
+	uint32_t length = reply->length;
+	uint8_t *buffer = reply->data;
+
+	REG_SET_3(DC_I2C_DATA, 0,
+		 DC_I2C_INDEX, length - 1,
+		 DC_I2C_DATA_RW, 1,
+		 DC_I2C_INDEX_WRITE, 1);
+
+	while (length) {
+		/* after reading the status,
+		 * if the I2C operation executed successfully
+		 * (i.e. DC_I2C_STATUS_DONE = 1) then the I2C controller
+		 * should read data bytes from I2C circular data buffer
+		 */
+
+		uint32_t i2c_data;
+
+		REG_GET(DC_I2C_DATA, DC_I2C_DATA, &i2c_data);
+		*buffer++ = i2c_data;
+
+		--length;
+	}
+}
+static void process_channel_reply_hw_dce100(
+	struct dce_i2c_hw *dce_i2c_hw,
+	struct i2c_reply_transaction_data *reply)
+{
+	uint32_t length = reply->length;
+	uint8_t *buffer = reply->data;
+
+	REG_SET_3(DC_I2C_DATA, 0,
+		 DC_I2C_INDEX, dce_i2c_hw->buffer_used_write,
+		 DC_I2C_DATA_RW, 1,
+		 DC_I2C_INDEX_WRITE, 1);
+
+	while (length) {
+		/* after reading the status,
+		 * if the I2C operation executed successfully
+		 * (i.e. DC_I2C_STATUS_DONE = 1) then the I2C controller
+		 * should read data bytes from I2C circular data buffer
+		 */
+
+		uint32_t i2c_data;
+
+		REG_GET(DC_I2C_DATA, DC_I2C_DATA, &i2c_data);
+		*buffer++ = i2c_data;
+
+		--length;
+	}
+}
+enum i2c_channel_operation_result dce_i2c_hw_engine_wait_on_operation_result(
+	struct dce_i2c_hw *dce_i2c_hw,
+	uint32_t timeout,
+	enum i2c_channel_operation_result expected_result)
+{
+	enum i2c_channel_operation_result result;
+	uint32_t i = 0;
+
+	if (!timeout)
+		return I2C_CHANNEL_OPERATION_SUCCEEDED;
+
+	do {
+
+		result = dce_i2c_hw->funcs->get_channel_status(
+				dce_i2c_hw, NULL);
+
+		if (result != expected_result)
+			break;
+
+		udelay(1);
+
+		++i;
+	} while (i < timeout);
+	return result;
+}
+static enum i2c_channel_operation_result get_channel_status_hw(
+	struct dce_i2c_hw *dce_i2c_hw,
+	uint8_t *returned_bytes)
+{
+	uint32_t i2c_sw_status = 0;
+	uint32_t value =
+		REG_GET(DC_I2C_SW_STATUS, DC_I2C_SW_STATUS, &i2c_sw_status);
+	if (i2c_sw_status == DC_I2C_STATUS__DC_I2C_STATUS_USED_BY_SW)
+		return I2C_CHANNEL_OPERATION_ENGINE_BUSY;
+	else if (value & dce_i2c_hw->masks->DC_I2C_SW_STOPPED_ON_NACK)
+		return I2C_CHANNEL_OPERATION_NO_RESPONSE;
+	else if (value & dce_i2c_hw->masks->DC_I2C_SW_TIMEOUT)
+		return I2C_CHANNEL_OPERATION_TIMEOUT;
+	else if (value & dce_i2c_hw->masks->DC_I2C_SW_ABORTED)
+		return I2C_CHANNEL_OPERATION_FAILED;
+	else if (value & dce_i2c_hw->masks->DC_I2C_SW_DONE)
+		return I2C_CHANNEL_OPERATION_SUCCEEDED;
+
+	/*
+	 * this is the case when HW used for communication, I2C_SW_STATUS
+	 * could be zero
+	 */
+	return I2C_CHANNEL_OPERATION_SUCCEEDED;
+}
+
+static void submit_channel_request_hw(
+	struct dce_i2c_hw *dce_i2c_hw,
+	struct i2c_request_transaction_data *request)
+{
+	request->status = I2C_CHANNEL_OPERATION_SUCCEEDED;
+
+	if (!dce_i2c_hw->funcs->process_transaction(dce_i2c_hw, request))
+		return;
+
+	if (dce_i2c_hw->funcs->is_hw_busy(dce_i2c_hw)) {
+		request->status = I2C_CHANNEL_OPERATION_ENGINE_BUSY;
+		return;
+	}
+
+	dce_i2c_hw->funcs->execute_transaction(dce_i2c_hw);
+
+
+}
+uint32_t get_reference_clock(
+		struct dc_bios *bios)
+{
+	struct dc_firmware_info info = { { 0 } };
+
+	if (bios->funcs->get_firmware_info(bios, &info) != BP_RESULT_OK)
+		return 0;
+
+	return info.pll_info.crystal_frequency;
+}
+
+static void execute_transaction_hw(
+	struct dce_i2c_hw *dce_i2c_hw)
+{
+	REG_UPDATE_N(SETUP, 5,
+		     FN(DC_I2C_DDC1_SETUP, DC_I2C_DDC1_DATA_DRIVE_EN), 0,
+		     FN(DC_I2C_DDC1_SETUP, DC_I2C_DDC1_CLK_DRIVE_EN), 0,
+		     FN(DC_I2C_DDC1_SETUP, DC_I2C_DDC1_DATA_DRIVE_SEL), 0,
+		     FN(DC_I2C_DDC1_SETUP, DC_I2C_DDC1_INTRA_TRANSACTION_DELAY), 0,
+		     FN(DC_I2C_DDC1_SETUP, DC_I2C_DDC1_INTRA_BYTE_DELAY), 0);
+
+
+	REG_UPDATE_5(DC_I2C_CONTROL,
+		     DC_I2C_SOFT_RESET, 0,
+		     DC_I2C_SW_STATUS_RESET, 0,
+		     DC_I2C_SEND_RESET, 0,
+		     DC_I2C_GO, 0,
+		     DC_I2C_TRANSACTION_COUNT, dce_i2c_hw->transaction_count - 1);
+
+	/* start I2C transfer */
+	REG_UPDATE(DC_I2C_CONTROL, DC_I2C_GO, 1);
+
+	/* all transactions were executed and HW buffer became empty
+	 * (even though it actually happens when status becomes DONE)
+	 */
+	dce_i2c_hw->transaction_count = 0;
+	dce_i2c_hw->buffer_used_bytes = 0;
+}
+static bool process_transaction_hw_dce80(
+	struct dce_i2c_hw *dce_i2c_hw,
+	struct i2c_request_transaction_data *request)
+{
+	uint32_t length = request->length;
+	uint8_t *buffer = request->data;
+
+	bool last_transaction = false;
+	uint32_t value = 0;
+
+	{
+
+		last_transaction = ((dce_i2c_hw->transaction_count == 3) ||
+				(request->action == DCE_I2C_TRANSACTION_ACTION_I2C_WRITE) ||
+				(request->action & DCE_I2C_TRANSACTION_ACTION_I2C_READ));
+
+
+		switch (dce_i2c_hw->transaction_count) {
+		case 0:
+			REG_UPDATE_5(DC_I2C_TRANSACTION0,
+				     DC_I2C_STOP_ON_NACK0, 1,
+				     DC_I2C_START0, 1,
+				     DC_I2C_RW0, 0 != (request->action & DCE_I2C_TRANSACTION_ACTION_I2C_READ),
+				     DC_I2C_COUNT0, length,
+				     DC_I2C_STOP0, last_transaction ? 1 : 0);
+			break;
+		case 1:
+			REG_UPDATE_5(DC_I2C_TRANSACTION1,
+				     DC_I2C_STOP_ON_NACK0, 1,
+				     DC_I2C_START0, 1,
+				     DC_I2C_RW0, 0 != (request->action & DCE_I2C_TRANSACTION_ACTION_I2C_READ),
+				     DC_I2C_COUNT0, length,
+				     DC_I2C_STOP0, last_transaction ? 1 : 0);
+			break;
+		case 2:
+			REG_UPDATE_5(DC_I2C_TRANSACTION2,
+				     DC_I2C_STOP_ON_NACK0, 1,
+				     DC_I2C_START0, 1,
+				     DC_I2C_RW0, 0 != (request->action & DCE_I2C_TRANSACTION_ACTION_I2C_READ),
+				     DC_I2C_COUNT0, length,
+				     DC_I2C_STOP0, last_transaction ? 1 : 0);
+			break;
+		case 3:
+			REG_UPDATE_5(DC_I2C_TRANSACTION3,
+				     DC_I2C_STOP_ON_NACK0, 1,
+				     DC_I2C_START0, 1,
+				     DC_I2C_RW0, 0 != (request->action & DCE_I2C_TRANSACTION_ACTION_I2C_READ),
+				     DC_I2C_COUNT0, length,
+				     DC_I2C_STOP0, last_transaction ? 1 : 0);
+			break;
+		default:
+			/* TODO Warning ? */
+			break;
+		}
+	}
+
+	/* Write the I2C address and I2C data
+	 * into the hardware circular buffer, one byte per entry.
+	 * As an example, the 7-bit I2C slave address for CRT monitor
+	 * for reading DDC/EDID information is 0b1010001.
+	 * For an I2C send operation, the LSB must be programmed to 0;
+	 * for I2C receive operation, the LSB must be programmed to 1.
+	 */
+
+	{
+		if (dce_i2c_hw->transaction_count == 0) {
+			value = REG_SET_4(DC_I2C_DATA, 0,
+					 DC_I2C_DATA_RW, false,
+					 DC_I2C_DATA, request->address,
+					 DC_I2C_INDEX, 0,
+					 DC_I2C_INDEX_WRITE, 1);
+		} else
+			value = REG_SET_2(DC_I2C_DATA, 0,
+					 DC_I2C_DATA_RW, false,
+					 DC_I2C_DATA, request->address);
+
+		if (!(request->action & DCE_I2C_TRANSACTION_ACTION_I2C_READ)) {
+
+			while (length) {
+				REG_SET_2(DC_I2C_DATA, value,
+					 DC_I2C_INDEX_WRITE, 0,
+					 DC_I2C_DATA, *buffer++);
+				--length;
+			}
+		}
+	}
+
+	++dce_i2c_hw->transaction_count;
+	dce_i2c_hw->buffer_used_bytes += length + 1;
+
+	return last_transaction;
+}
+
+#define STOP_TRANS_PREDICAT \
+		((dce_i2c_hw->transaction_count == 3) ||	\
+				(request->action == DCE_I2C_TRANSACTION_ACTION_I2C_WRITE) ||	\
+				(request->action & DCE_I2C_TRANSACTION_ACTION_I2C_READ))
+
+#define SET_I2C_TRANSACTION(id)	\
+		do {	\
+			REG_UPDATE_N(DC_I2C_TRANSACTION##id, 5,	\
+				FN(DC_I2C_TRANSACTION0, DC_I2C_STOP_ON_NACK0), 1,	\
+				FN(DC_I2C_TRANSACTION0, DC_I2C_START0), 1,	\
+				FN(DC_I2C_TRANSACTION0, DC_I2C_STOP0), STOP_TRANS_PREDICAT ? 1:0,	\
+				FN(DC_I2C_TRANSACTION0, DC_I2C_RW0), (0 != (request->action & DCE_I2C_TRANSACTION_ACTION_I2C_READ)),	\
+				FN(DC_I2C_TRANSACTION0, DC_I2C_COUNT0), length);	\
+				if (STOP_TRANS_PREDICAT)	\
+					last_transaction = true;	\
+		} while (false)
+
+static bool process_transaction_hw_dce100(
+	struct dce_i2c_hw *dce_i2c_hw,
+	struct i2c_request_transaction_data *request)
+{
+	uint32_t length = request->length;
+	uint8_t *buffer = request->data;
+	uint32_t value = 0;
+
+	bool last_transaction = false;
+
+	switch (dce_i2c_hw->transaction_count) {
+	case 0:
+		SET_I2C_TRANSACTION(0);
+		break;
+	case 1:
+		SET_I2C_TRANSACTION(1);
+		break;
+	case 2:
+		SET_I2C_TRANSACTION(2);
+		break;
+	case 3:
+		SET_I2C_TRANSACTION(3);
+		break;
+	default:
+		/* TODO Warning ? */
+		break;
+	}
+
+
+	/* Write the I2C address and I2C data
+	 * into the hardware circular buffer, one byte per entry.
+	 * As an example, the 7-bit I2C slave address for CRT monitor
+	 * for reading DDC/EDID information is 0b1010001.
+	 * For an I2C send operation, the LSB must be programmed to 0;
+	 * for I2C receive operation, the LSB must be programmed to 1.
+	 */
+	if (dce_i2c_hw->transaction_count == 0) {
+		value = REG_SET_4(DC_I2C_DATA, 0,
+				  DC_I2C_DATA_RW, false,
+				  DC_I2C_DATA, request->address,
+				  DC_I2C_INDEX, 0,
+				  DC_I2C_INDEX_WRITE, 1);
+		dce_i2c_hw->buffer_used_write = 0;
+	} else
+		value = REG_SET_2(DC_I2C_DATA, 0,
+			  DC_I2C_DATA_RW, false,
+			  DC_I2C_DATA, request->address);
+
+	dce_i2c_hw->buffer_used_write++;
+
+	if (!(request->action & DCE_I2C_TRANSACTION_ACTION_I2C_READ)) {
+		while (length) {
+			REG_SET_2(DC_I2C_DATA, value,
+				  DC_I2C_INDEX_WRITE, 0,
+				  DC_I2C_DATA, *buffer++);
+			dce_i2c_hw->buffer_used_write++;
+			--length;
+		}
+	}
+
+	++dce_i2c_hw->transaction_count;
+	dce_i2c_hw->buffer_used_bytes += length + 1;
+
+	return last_transaction;
+}
+static uint32_t get_transaction_timeout_hw(
+	const struct dce_i2c_hw *dce_i2c_hw,
+	uint32_t length)
+{
+
+	uint32_t speed = dce_i2c_hw->funcs->get_speed(dce_i2c_hw);
+
+
+
+	uint32_t period_timeout;
+	uint32_t num_of_clock_stretches;
+
+	if (!speed)
+		return 0;
+
+	period_timeout = (1000 * TRANSACTION_TIMEOUT_IN_I2C_CLOCKS) / speed;
+
+	num_of_clock_stretches = 1 + (length << 3) + 1;
+	num_of_clock_stretches +=
+		(dce_i2c_hw->buffer_used_bytes << 3) +
+		(dce_i2c_hw->transaction_count << 1);
+
+	return period_timeout * num_of_clock_stretches;
+}
+
+static void release_engine_dce_hw(
+	struct resource_pool *pool,
+	struct dce_i2c_hw *dce_i2c_hw)
+{
+	pool->i2c_hw_buffer_in_use = false;
+
+	dce_i2c_hw->funcs->release_engine(dce_i2c_hw);
+	dal_ddc_close(dce_i2c_hw->ddc);
+
+	dce_i2c_hw->ddc = NULL;
+}
+
+static void release_engine_hw(
+	struct dce_i2c_hw *dce_i2c_hw)
+{
+	bool safe_to_reset;
+
+	/* Restore original HW engine speed */
+
+	dce_i2c_hw->funcs->set_speed(dce_i2c_hw, dce_i2c_hw->original_speed);
+
+	/* Release I2C */
+	REG_UPDATE(DC_I2C_ARBITRATION, DC_I2C_SW_DONE_USING_I2C_REG, 1);
+
+	/* Reset HW engine */
+	{
+		uint32_t i2c_sw_status = 0;
+
+		REG_GET(DC_I2C_SW_STATUS, DC_I2C_SW_STATUS, &i2c_sw_status);
+		/* if used by SW, safe to reset */
+		safe_to_reset = (i2c_sw_status == 1);
+	}
+
+	if (safe_to_reset)
+		REG_UPDATE_2(DC_I2C_CONTROL,
+			     DC_I2C_SOFT_RESET, 1,
+			     DC_I2C_SW_STATUS_RESET, 1);
+	else
+		REG_UPDATE(DC_I2C_CONTROL, DC_I2C_SW_STATUS_RESET, 1);
+	/* HW I2c engine - clock gating feature */
+	if (!dce_i2c_hw->engine_keep_power_up_count)
+		dce_i2c_hw->funcs->disable_i2c_hw_engine(dce_i2c_hw);
+
+}
+
+
+static void disable_i2c_hw_engine(
+	struct dce_i2c_hw *dce_i2c_hw)
+{
+	REG_UPDATE_N(SETUP, 1, FN(SETUP, DC_I2C_DDC1_ENABLE), 0);
+}
+static uint32_t get_speed_hw(
+	const struct dce_i2c_hw *dce_i2c_hw)
+{
+	uint32_t pre_scale = 0;
+
+	REG_GET(SPEED, DC_I2C_DDC1_PRESCALE, &pre_scale);
+
+	/* [anaumov] it seems following is unnecessary */
+	/*ASSERT(value.bits.DC_I2C_DDC1_PRESCALE);*/
+	return pre_scale ?
+		dce_i2c_hw->reference_frequency / pre_scale :
+		dce_i2c_hw->default_speed;
+}
+static uint32_t get_hw_buffer_available_size(
+	const struct dce_i2c_hw *dce_i2c_hw)
+{
+	return dce_i2c_hw->buffer_size -
+			dce_i2c_hw->buffer_used_bytes;
+}
+bool dce_i2c_hw_engine_submit_request(
+	struct dce_i2c_hw *dce_i2c_hw,
+	struct dce_i2c_transaction_request *dce_i2c_request,
+	bool middle_of_transaction)
+{
+
+	struct i2c_request_transaction_data request;
+
+	uint32_t transaction_timeout;
+
+	enum i2c_channel_operation_result operation_result;
+
+	bool result = false;
+
+	/* We need following:
+	 * transaction length will not exceed
+	 * the number of free bytes in HW buffer (minus one for address)
+	 */
+
+	if (dce_i2c_request->payload.length >=
+			get_hw_buffer_available_size(dce_i2c_hw)) {
+		dce_i2c_request->status =
+			DCE_I2C_TRANSACTION_STATUS_FAILED_BUFFER_OVERFLOW;
+		return false;
+	}
+
+	if (dce_i2c_request->operation == DCE_I2C_TRANSACTION_READ)
+		request.action = middle_of_transaction ?
+			DCE_I2C_TRANSACTION_ACTION_I2C_READ_MOT :
+			DCE_I2C_TRANSACTION_ACTION_I2C_READ;
+	else if (dce_i2c_request->operation == DCE_I2C_TRANSACTION_WRITE)
+		request.action = middle_of_transaction ?
+			DCE_I2C_TRANSACTION_ACTION_I2C_WRITE_MOT :
+			DCE_I2C_TRANSACTION_ACTION_I2C_WRITE;
+	else {
+		dce_i2c_request->status =
+			DCE_I2C_TRANSACTION_STATUS_FAILED_INVALID_OPERATION;
+		/* [anaumov] in DAL2, there was no "return false" */
+		return false;
+	}
+
+	request.address = (uint8_t) dce_i2c_request->payload.address;
+	request.length = dce_i2c_request->payload.length;
+	request.data = dce_i2c_request->payload.data;
+
+	/* obtain timeout value before submitting request */
+
+	transaction_timeout = get_transaction_timeout_hw(
+		dce_i2c_hw, dce_i2c_request->payload.length + 1);
+
+	submit_channel_request_hw(
+		dce_i2c_hw, &request);
+
+	if ((request.status == I2C_CHANNEL_OPERATION_FAILED) ||
+		(request.status == I2C_CHANNEL_OPERATION_ENGINE_BUSY)) {
+		dce_i2c_request->status =
+			DCE_I2C_TRANSACTION_STATUS_FAILED_CHANNEL_BUSY;
+		return false;
+	}
+
+	/* wait until transaction proceed */
+
+	operation_result = dce_i2c_hw_engine_wait_on_operation_result(
+		dce_i2c_hw,
+		transaction_timeout,
+		I2C_CHANNEL_OPERATION_ENGINE_BUSY);
+
+	/* update transaction status */
+
+	switch (operation_result) {
+	case I2C_CHANNEL_OPERATION_SUCCEEDED:
+		dce_i2c_request->status =
+			DCE_I2C_TRANSACTION_STATUS_SUCCEEDED;
+		result = true;
+	break;
+	case I2C_CHANNEL_OPERATION_NO_RESPONSE:
+		dce_i2c_request->status =
+			DCE_I2C_TRANSACTION_STATUS_FAILED_NACK;
+	break;
+	case I2C_CHANNEL_OPERATION_TIMEOUT:
+		dce_i2c_request->status =
+			DCE_I2C_TRANSACTION_STATUS_FAILED_TIMEOUT;
+	break;
+	case I2C_CHANNEL_OPERATION_FAILED:
+		dce_i2c_request->status =
+			DCE_I2C_TRANSACTION_STATUS_FAILED_INCOMPLETE;
+	break;
+	default:
+		dce_i2c_request->status =
+			DCE_I2C_TRANSACTION_STATUS_FAILED_OPERATION;
+	}
+
+	if (result && (dce_i2c_request->operation == DCE_I2C_TRANSACTION_READ)) {
+		struct i2c_reply_transaction_data reply;
+
+		reply.data = dce_i2c_request->payload.data;
+		reply.length = dce_i2c_request->payload.length;
+
+		dce_i2c_hw->funcs->process_channel_reply(dce_i2c_hw, &reply);
+
+
+	}
+
+	return result;
+}
+
+bool dce_i2c_submit_command_hw(
+	struct resource_pool *pool,
+	struct ddc *ddc,
+	struct i2c_command *cmd,
+	struct dce_i2c_hw *dce_i2c_hw)
+{
+	uint8_t index_of_payload = 0;
+	bool result;
+
+	dce_i2c_hw->funcs->set_speed(dce_i2c_hw, cmd->speed);
+
+	result = true;
+
+	while (index_of_payload < cmd->number_of_payloads) {
+		bool mot = (index_of_payload != cmd->number_of_payloads - 1);
+
+		struct i2c_payload *payload = cmd->payloads + index_of_payload;
+
+		struct dce_i2c_transaction_request request = { 0 };
+
+		request.operation = payload->write ?
+			DCE_I2C_TRANSACTION_WRITE :
+			DCE_I2C_TRANSACTION_READ;
+
+		request.payload.address_space =
+			DCE_I2C_TRANSACTION_ADDRESS_SPACE_I2C;
+		request.payload.address = (payload->address << 1) |
+			!payload->write;
+		request.payload.length = payload->length;
+		request.payload.data = payload->data;
+
+
+		if (!dce_i2c_hw_engine_submit_request(
+				dce_i2c_hw, &request, mot)) {
+			result = false;
+			break;
+		}
+
+
+
+		++index_of_payload;
+	}
+
+	release_engine_dce_hw(pool, dce_i2c_hw);
+
+	return result;
+}
+static const struct dce_i2c_hw_funcs dce100_i2c_hw_funcs = {
+		.setup_engine = setup_engine_hw_dce100,
+		.set_speed = set_speed_hw_dce100,
+		.get_speed = get_speed_hw,
+		.release_engine = release_engine_hw,
+		.process_transaction = process_transaction_hw_dce100,
+		.process_channel_reply = process_channel_reply_hw_dce100,
+		.is_hw_busy = is_hw_busy,
+		.get_channel_status = get_channel_status_hw,
+		.execute_transaction = execute_transaction_hw,
+		.disable_i2c_hw_engine = disable_i2c_hw_engine
+};
+static const struct dce_i2c_hw_funcs dce80_i2c_hw_funcs = {
+		.setup_engine = setup_engine_hw_dce80,
+		.set_speed = set_speed_hw_dce80,
+		.get_speed = get_speed_hw,
+		.release_engine = release_engine_hw,
+		.process_transaction = process_transaction_hw_dce80,
+		.process_channel_reply = process_channel_reply_hw_dce80,
+		.is_hw_busy = is_hw_busy,
+		.get_channel_status = get_channel_status_hw,
+		.execute_transaction = execute_transaction_hw,
+		.disable_i2c_hw_engine = disable_i2c_hw_engine
+};
+
+
+
+void dce_i2c_hw_construct(
+	struct dce_i2c_hw *dce_i2c_hw,
+	struct dc_context *ctx,
+	uint32_t engine_id,
+	const struct dce_i2c_registers *regs,
+	const struct dce_i2c_shift *shifts,
+	const struct dce_i2c_mask *masks)
+{
+	dce_i2c_hw->ctx = ctx;
+	dce_i2c_hw->engine_id = engine_id;
+	dce_i2c_hw->reference_frequency = get_reference_clock(ctx->dc_bios) >> 1;
+	dce_i2c_hw->regs = regs;
+	dce_i2c_hw->shifts = shifts;
+	dce_i2c_hw->masks = masks;
+	dce_i2c_hw->buffer_used_bytes = 0;
+	dce_i2c_hw->transaction_count = 0;
+	dce_i2c_hw->engine_keep_power_up_count = 1;
+	dce_i2c_hw->original_speed = DEFAULT_I2C_HW_SPEED;
+	dce_i2c_hw->default_speed = DEFAULT_I2C_HW_SPEED;
+	dce_i2c_hw->send_reset_length = 0;
+	dce_i2c_hw->setup_limit = I2C_SETUP_TIME_LIMIT_DCE;
+	dce_i2c_hw->funcs = &dce80_i2c_hw_funcs;
+	dce_i2c_hw->buffer_size = I2C_HW_BUFFER_SIZE_DCE;
+}
+
+void dce100_i2c_hw_construct(
+	struct dce_i2c_hw *dce_i2c_hw,
+	struct dc_context *ctx,
+	uint32_t engine_id,
+	const struct dce_i2c_registers *regs,
+	const struct dce_i2c_shift *shifts,
+	const struct dce_i2c_mask *masks)
+{
+
+	uint32_t xtal_ref_div = 0;
+
+	dce_i2c_hw_construct(dce_i2c_hw,
+			ctx,
+			engine_id,
+			regs,
+			shifts,
+			masks);
+	dce_i2c_hw->funcs = &dce100_i2c_hw_funcs;
+	dce_i2c_hw->buffer_size = I2C_HW_BUFFER_SIZE_DCE100;
+
+	REG_GET(MICROSECOND_TIME_BASE_DIV, XTAL_REF_DIV, &xtal_ref_div);
+
+	if (xtal_ref_div == 0)
+		xtal_ref_div = 2;
+
+	/*Calculating Reference Clock by divding original frequency by
+	 * XTAL_REF_DIV.
+	 * At upper level, uint32_t reference_frequency =
+	 *  dal_dce_i2c_get_reference_clock(as) >> 1
+	 *  which already divided by 2. So we need x2 to get original
+	 *  reference clock from ppll_info
+	 */
+	dce_i2c_hw->reference_frequency =
+		(dce_i2c_hw->reference_frequency * 2) / xtal_ref_div;
+}
+
+void dce112_i2c_hw_construct(
+	struct dce_i2c_hw *dce_i2c_hw,
+	struct dc_context *ctx,
+	uint32_t engine_id,
+	const struct dce_i2c_registers *regs,
+	const struct dce_i2c_shift *shifts,
+	const struct dce_i2c_mask *masks)
+{
+	dce100_i2c_hw_construct(dce_i2c_hw,
+			ctx,
+			engine_id,
+			regs,
+			shifts,
+			masks);
+	dce_i2c_hw->default_speed = DEFAULT_I2C_HW_SPEED_100KHZ;
+}
+
+void dcn1_i2c_hw_construct(
+	struct dce_i2c_hw *dce_i2c_hw,
+	struct dc_context *ctx,
+	uint32_t engine_id,
+	const struct dce_i2c_registers *regs,
+	const struct dce_i2c_shift *shifts,
+	const struct dce_i2c_mask *masks)
+{
+	dce112_i2c_hw_construct(dce_i2c_hw,
+			ctx,
+			engine_id,
+			regs,
+			shifts,
+			masks);
+	dce_i2c_hw->setup_limit = I2C_SETUP_TIME_LIMIT_DCN;
+}
+

drivers/gpu/drm/amd/display/dc/dce/dce_i2c_hw.h

+/*
+ * Copyright 2018 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 __DCE_I2C_HW_H__
+#define __DCE_I2C_HW_H__
+
+enum dc_i2c_status {
+	DC_I2C_STATUS__DC_I2C_STATUS_IDLE,
+	DC_I2C_STATUS__DC_I2C_STATUS_USED_BY_SW,
+	DC_I2C_STATUS__DC_I2C_STATUS_USED_BY_HW
+};
+
+enum dc_i2c_arbitration {
+	DC_I2C_ARBITRATION__DC_I2C_SW_PRIORITY_NORMAL,
+	DC_I2C_ARBITRATION__DC_I2C_SW_PRIORITY_HIGH
+};
+
+enum i2c_channel_operation_result {
+	I2C_CHANNEL_OPERATION_SUCCEEDED,
+	I2C_CHANNEL_OPERATION_FAILED,
+	I2C_CHANNEL_OPERATION_NOT_GRANTED,
+	I2C_CHANNEL_OPERATION_IS_BUSY,
+	I2C_CHANNEL_OPERATION_NO_HANDLE_PROVIDED,
+	I2C_CHANNEL_OPERATION_CHANNEL_IN_USE,
+	I2C_CHANNEL_OPERATION_CHANNEL_CLIENT_MAX_ALLOWED,
+	I2C_CHANNEL_OPERATION_ENGINE_BUSY,
+	I2C_CHANNEL_OPERATION_TIMEOUT,
+	I2C_CHANNEL_OPERATION_NO_RESPONSE,
+	I2C_CHANNEL_OPERATION_HW_REQUEST_I2C_BUS,
+	I2C_CHANNEL_OPERATION_WRONG_PARAMETER,
+	I2C_CHANNEL_OPERATION_OUT_NB_OF_RETRIES,
+	I2C_CHANNEL_OPERATION_NOT_STARTED
+};
+
+
+enum dce_i2c_transaction_action {
+	DCE_I2C_TRANSACTION_ACTION_I2C_WRITE = 0x00,
+	DCE_I2C_TRANSACTION_ACTION_I2C_READ = 0x10,
+	DCE_I2C_TRANSACTION_ACTION_I2C_STATUS_REQUEST = 0x20,
+
+	DCE_I2C_TRANSACTION_ACTION_I2C_WRITE_MOT = 0x40,
+	DCE_I2C_TRANSACTION_ACTION_I2C_READ_MOT = 0x50,
+	DCE_I2C_TRANSACTION_ACTION_I2C_STATUS_REQUEST_MOT = 0x60,
+
+	DCE_I2C_TRANSACTION_ACTION_DP_WRITE = 0x80,
+	DCE_I2C_TRANSACTION_ACTION_DP_READ = 0x90
+};
+
+enum {
+	I2C_SETUP_TIME_LIMIT_DCE = 255,
+	I2C_SETUP_TIME_LIMIT_DCN = 3,
+	I2C_HW_BUFFER_SIZE_DCE100 = 538,
+	I2C_HW_BUFFER_SIZE_DCE = 144,
+	I2C_SEND_RESET_LENGTH_9 = 9,
+	I2C_SEND_RESET_LENGTH_10 = 10,
+	DEFAULT_I2C_HW_SPEED = 50,
+	DEFAULT_I2C_HW_SPEED_100KHZ = 100,
+	TRANSACTION_TIMEOUT_IN_I2C_CLOCKS = 32,
+};
+
+#define I2C_HW_ENGINE_COMMON_REG_LIST(id)\
+	SRI(SETUP, DC_I2C_DDC, id),\
+	SRI(SPEED, DC_I2C_DDC, id),\
+	SR(DC_I2C_ARBITRATION),\
+	SR(DC_I2C_CONTROL),\
+	SR(DC_I2C_SW_STATUS),\
+	SR(DC_I2C_TRANSACTION0),\
+	SR(DC_I2C_TRANSACTION1),\
+	SR(DC_I2C_TRANSACTION2),\
+	SR(DC_I2C_TRANSACTION3),\
+	SR(DC_I2C_DATA),\
+	SR(MICROSECOND_TIME_BASE_DIV)
+
+#define I2C_SF(reg_name, field_name, post_fix)\
+	.field_name = reg_name ## __ ## field_name ## post_fix
+
+#define I2C_COMMON_MASK_SH_LIST_DCE_COMMON_BASE(mask_sh)\
+	I2C_SF(DC_I2C_DDC1_SETUP, DC_I2C_DDC1_ENABLE, mask_sh),\
+	I2C_SF(DC_I2C_DDC1_SETUP, DC_I2C_DDC1_TIME_LIMIT, mask_sh),\
+	I2C_SF(DC_I2C_DDC1_SETUP, DC_I2C_DDC1_DATA_DRIVE_EN, mask_sh),\
+	I2C_SF(DC_I2C_DDC1_SETUP, DC_I2C_DDC1_CLK_DRIVE_EN, mask_sh),\
+	I2C_SF(DC_I2C_DDC1_SETUP, DC_I2C_DDC1_DATA_DRIVE_SEL, mask_sh),\
+	I2C_SF(DC_I2C_DDC1_SETUP, DC_I2C_DDC1_INTRA_TRANSACTION_DELAY, mask_sh),\
+	I2C_SF(DC_I2C_DDC1_SETUP, DC_I2C_DDC1_INTRA_BYTE_DELAY, mask_sh),\
+	I2C_SF(DC_I2C_ARBITRATION, DC_I2C_SW_DONE_USING_I2C_REG, mask_sh),\
+	I2C_SF(DC_I2C_ARBITRATION, DC_I2C_NO_QUEUED_SW_GO, mask_sh),\
+	I2C_SF(DC_I2C_ARBITRATION, DC_I2C_SW_PRIORITY, mask_sh),\
+	I2C_SF(DC_I2C_CONTROL, DC_I2C_SOFT_RESET, mask_sh),\
+	I2C_SF(DC_I2C_CONTROL, DC_I2C_SW_STATUS_RESET, mask_sh),\
+	I2C_SF(DC_I2C_CONTROL, DC_I2C_GO, mask_sh),\
+	I2C_SF(DC_I2C_CONTROL, DC_I2C_SEND_RESET, mask_sh),\
+	I2C_SF(DC_I2C_CONTROL, DC_I2C_TRANSACTION_COUNT, mask_sh),\
+	I2C_SF(DC_I2C_CONTROL, DC_I2C_DDC_SELECT, mask_sh),\
+	I2C_SF(DC_I2C_DDC1_SPEED, DC_I2C_DDC1_PRESCALE, mask_sh),\
+	I2C_SF(DC_I2C_DDC1_SPEED, DC_I2C_DDC1_THRESHOLD, mask_sh),\
+	I2C_SF(DC_I2C_SW_STATUS, DC_I2C_SW_STOPPED_ON_NACK, mask_sh),\
+	I2C_SF(DC_I2C_SW_STATUS, DC_I2C_SW_TIMEOUT, mask_sh),\
+	I2C_SF(DC_I2C_SW_STATUS, DC_I2C_SW_ABORTED, mask_sh),\
+	I2C_SF(DC_I2C_SW_STATUS, DC_I2C_SW_DONE, mask_sh),\
+	I2C_SF(DC_I2C_SW_STATUS, DC_I2C_SW_STATUS, mask_sh),\
+	I2C_SF(DC_I2C_TRANSACTION0, DC_I2C_STOP_ON_NACK0, mask_sh),\
+	I2C_SF(DC_I2C_TRANSACTION0, DC_I2C_START0, mask_sh),\
+	I2C_SF(DC_I2C_TRANSACTION0, DC_I2C_RW0, mask_sh),\
+	I2C_SF(DC_I2C_TRANSACTION0, DC_I2C_STOP0, mask_sh),\
+	I2C_SF(DC_I2C_TRANSACTION0, DC_I2C_COUNT0, mask_sh),\
+	I2C_SF(DC_I2C_DATA, DC_I2C_DATA_RW, mask_sh),\
+	I2C_SF(DC_I2C_DATA, DC_I2C_DATA, mask_sh),\
+	I2C_SF(DC_I2C_DATA, DC_I2C_INDEX, mask_sh),\
+	I2C_SF(DC_I2C_DATA, DC_I2C_INDEX_WRITE, mask_sh),\
+	I2C_SF(MICROSECOND_TIME_BASE_DIV, XTAL_REF_DIV, mask_sh)
+
+#define I2C_COMMON_MASK_SH_LIST_DCE110(mask_sh)\
+	I2C_COMMON_MASK_SH_LIST_DCE_COMMON_BASE(mask_sh),\
+	I2C_SF(DC_I2C_DDC1_SPEED, DC_I2C_DDC1_START_STOP_TIMING_CNTL, mask_sh)
+
+struct dce_i2c_shift {
+	uint8_t DC_I2C_DDC1_ENABLE;
+	uint8_t DC_I2C_DDC1_TIME_LIMIT;
+	uint8_t DC_I2C_DDC1_DATA_DRIVE_EN;
+	uint8_t DC_I2C_DDC1_CLK_DRIVE_EN;
+	uint8_t DC_I2C_DDC1_DATA_DRIVE_SEL;
+	uint8_t DC_I2C_DDC1_INTRA_TRANSACTION_DELAY;
+	uint8_t DC_I2C_DDC1_INTRA_BYTE_DELAY;
+	uint8_t DC_I2C_SW_DONE_USING_I2C_REG;
+	uint8_t DC_I2C_NO_QUEUED_SW_GO;
+	uint8_t DC_I2C_SW_PRIORITY;
+	uint8_t DC_I2C_SOFT_RESET;
+	uint8_t DC_I2C_SW_STATUS_RESET;
+	uint8_t DC_I2C_GO;
+	uint8_t DC_I2C_SEND_RESET;
+	uint8_t DC_I2C_TRANSACTION_COUNT;
+	uint8_t DC_I2C_DDC_SELECT;
+	uint8_t DC_I2C_DDC1_PRESCALE;
+	uint8_t DC_I2C_DDC1_THRESHOLD;
+	uint8_t DC_I2C_DDC1_START_STOP_TIMING_CNTL;
+	uint8_t DC_I2C_SW_STOPPED_ON_NACK;
+	uint8_t DC_I2C_SW_TIMEOUT;
+	uint8_t DC_I2C_SW_ABORTED;
+	uint8_t DC_I2C_SW_DONE;
+	uint8_t DC_I2C_SW_STATUS;
+	uint8_t DC_I2C_STOP_ON_NACK0;
+	uint8_t DC_I2C_START0;
+	uint8_t DC_I2C_RW0;
+	uint8_t DC_I2C_STOP0;
+	uint8_t DC_I2C_COUNT0;
+	uint8_t DC_I2C_DATA_RW;
+	uint8_t DC_I2C_DATA;
+	uint8_t DC_I2C_INDEX;
+	uint8_t DC_I2C_INDEX_WRITE;
+	uint8_t XTAL_REF_DIV;
+};
+
+struct dce_i2c_mask {
+	uint32_t DC_I2C_DDC1_ENABLE;
+	uint32_t DC_I2C_DDC1_TIME_LIMIT;
+	uint32_t DC_I2C_DDC1_DATA_DRIVE_EN;
+	uint32_t DC_I2C_DDC1_CLK_DRIVE_EN;
+	uint32_t DC_I2C_DDC1_DATA_DRIVE_SEL;
+	uint32_t DC_I2C_DDC1_INTRA_TRANSACTION_DELAY;
+	uint32_t DC_I2C_DDC1_INTRA_BYTE_DELAY;
+	uint32_t DC_I2C_SW_DONE_USING_I2C_REG;
+	uint32_t DC_I2C_NO_QUEUED_SW_GO;
+	uint32_t DC_I2C_SW_PRIORITY;
+	uint32_t DC_I2C_SOFT_RESET;
+	uint32_t DC_I2C_SW_STATUS_RESET;
+	uint32_t DC_I2C_GO;
+	uint32_t DC_I2C_SEND_RESET;
+	uint32_t DC_I2C_TRANSACTION_COUNT;
+	uint32_t DC_I2C_DDC_SELECT;
+	uint32_t DC_I2C_DDC1_PRESCALE;
+	uint32_t DC_I2C_DDC1_THRESHOLD;
+	uint32_t DC_I2C_DDC1_START_STOP_TIMING_CNTL;
+	uint32_t DC_I2C_SW_STOPPED_ON_NACK;
+	uint32_t DC_I2C_SW_TIMEOUT;
+	uint32_t DC_I2C_SW_ABORTED;
+	uint32_t DC_I2C_SW_DONE;
+	uint32_t DC_I2C_SW_STATUS;
+	uint32_t DC_I2C_STOP_ON_NACK0;
+	uint32_t DC_I2C_START0;
+	uint32_t DC_I2C_RW0;
+	uint32_t DC_I2C_STOP0;
+	uint32_t DC_I2C_COUNT0;
+	uint32_t DC_I2C_DATA_RW;
+	uint32_t DC_I2C_DATA;
+	uint32_t DC_I2C_INDEX;
+	uint32_t DC_I2C_INDEX_WRITE;
+	uint32_t XTAL_REF_DIV;
+};
+
+struct dce_i2c_registers {
+	uint32_t SETUP;
+	uint32_t SPEED;
+	uint32_t DC_I2C_ARBITRATION;
+	uint32_t DC_I2C_CONTROL;
+	uint32_t DC_I2C_SW_STATUS;
+	uint32_t DC_I2C_TRANSACTION0;
+	uint32_t DC_I2C_TRANSACTION1;
+	uint32_t DC_I2C_TRANSACTION2;
+	uint32_t DC_I2C_TRANSACTION3;
+	uint32_t DC_I2C_DATA;
+	uint32_t MICROSECOND_TIME_BASE_DIV;
+};
+
+enum dce_i2c_transaction_address_space {
+	DCE_I2C_TRANSACTION_ADDRESS_SPACE_I2C = 1,
+	DCE_I2C_TRANSACTION_ADDRESS_SPACE_DPCD
+};
+
+struct i2c_request_transaction_data {
+	enum dce_i2c_transaction_action action;
+	enum i2c_channel_operation_result status;
+	uint8_t address;
+	uint32_t length;
+	uint8_t *data;
+};
+
+struct i2c_reply_transaction_data {
+	uint32_t length;
+	uint8_t *data;
+};
+
+struct dce_i2c_hw {
+	struct ddc *ddc;
+	uint32_t original_speed;
+	uint32_t engine_keep_power_up_count;
+	uint32_t transaction_count;
+	uint32_t buffer_used_bytes;
+	uint32_t buffer_used_write;
+	uint32_t reference_frequency;
+	uint32_t default_speed;
+	uint32_t engine_id;
+	uint32_t setup_limit;
+	uint32_t send_reset_length;
+	uint32_t buffer_size;
+	struct dc_context *ctx;
+
+	const struct dce_i2c_hw_funcs *funcs;
+	const struct dce_i2c_registers *regs;
+	const struct dce_i2c_shift *shifts;
+	const struct dce_i2c_mask *masks;
+};
+
+
+struct dce_i2c_hw_funcs {
+	bool (*setup_engine)(
+		struct dce_i2c_hw *dce_i2c_hw);
+	void (*set_speed)(
+		struct dce_i2c_hw *dce_i2c_hw,
+		uint32_t speed);
+	uint32_t (*get_speed)(
+		const struct dce_i2c_hw *dce_i2c_hw);
+	void (*release_engine)(
+		struct dce_i2c_hw *dce_i2c_hw);
+	bool (*process_transaction)(
+		struct dce_i2c_hw *dce_i2c_hw,
+		struct i2c_request_transaction_data *request);
+	void (*process_channel_reply)(
+		struct dce_i2c_hw *dce_i2c_hw,
+		struct i2c_reply_transaction_data *reply);
+	bool (*is_hw_busy)(
+		struct dce_i2c_hw *dce_i2c_hw);
+	enum i2c_channel_operation_result (*get_channel_status)(
+		struct dce_i2c_hw *dce_i2c_hw,
+		uint8_t *returned_bytes);
+	void (*execute_transaction)(
+		struct dce_i2c_hw *dce_i2c_hw);
+	void (*disable_i2c_hw_engine)(
+		struct dce_i2c_hw *dce_i2c_hw);
+};
+
+void dce_i2c_hw_construct(
+	struct dce_i2c_hw *dce_i2c_hw,
+	struct dc_context *ctx,
+	uint32_t engine_id,
+	const struct dce_i2c_registers *regs,
+	const struct dce_i2c_shift *shifts,
+	const struct dce_i2c_mask *masks);
+
+void dce100_i2c_hw_construct(
+	struct dce_i2c_hw *dce_i2c_hw,
+	struct dc_context *ctx,
+	uint32_t engine_id,
+	const struct dce_i2c_registers *regs,
+	const struct dce_i2c_shift *shifts,
+	const struct dce_i2c_mask *masks);
+
+void dce112_i2c_hw_construct(
+	struct dce_i2c_hw *dce_i2c_hw,
+	struct dc_context *ctx,
+	uint32_t engine_id,
+	const struct dce_i2c_registers *regs,
+	const struct dce_i2c_shift *shifts,
+	const struct dce_i2c_mask *masks);
+
+void dcn1_i2c_hw_construct(
+	struct dce_i2c_hw *dce_i2c_hw,
+	struct dc_context *ctx,
+	uint32_t engine_id,
+	const struct dce_i2c_registers *regs,
+	const struct dce_i2c_shift *shifts,
+	const struct dce_i2c_mask *masks);
+
+bool dce_i2c_submit_command_hw(
+	struct resource_pool *pool,
+	struct ddc *ddc,
+	struct i2c_command *cmd,
+	struct dce_i2c_hw *dce_i2c_hw);
+
+struct dce_i2c_hw *acquire_i2c_hw_engine(
+	struct resource_pool *pool,
+	struct ddc *ddc);
+
+#endif

drivers/gpu/drm/amd/display/dc/dce/dce_i2c_sw.c

+/*
+ * Copyright 2018 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
+ *
+ */
+#include "dce_i2c.h"
+#include "dce_i2c_sw.h"
+#include "include/gpio_service_interface.h"
+#define SCL false
+#define SDA true
+
+void dce_i2c_sw_construct(
+	struct dce_i2c_sw *dce_i2c_sw,
+	struct dc_context *ctx)
+{
+	dce_i2c_sw->ctx = ctx;
+}
+
+static inline bool read_bit_from_ddc(
+	struct ddc *ddc,
+	bool data_nor_clock)
+{
+	uint32_t value = 0;
+
+	if (data_nor_clock)
+		dal_gpio_get_value(ddc->pin_data, &value);
+	else
+		dal_gpio_get_value(ddc->pin_clock, &value);
+
+	return (value != 0);
+}
+
+static inline void write_bit_to_ddc(
+	struct ddc *ddc,
+	bool data_nor_clock,
+	bool bit)
+{
+	uint32_t value = bit ? 1 : 0;
+
+	if (data_nor_clock)
+		dal_gpio_set_value(ddc->pin_data, value);
+	else
+		dal_gpio_set_value(ddc->pin_clock, value);
+}
+
+static void release_engine_dce_sw(
+	struct resource_pool *pool,
+	struct dce_i2c_sw *dce_i2c_sw)
+{
+	dal_ddc_close(dce_i2c_sw->ddc);
+	dce_i2c_sw->ddc = NULL;
+}
+
+enum i2c_channel_operation_result dce_i2c_sw_engine_get_channel_status(
+	struct dce_i2c_sw *engine,
+	uint8_t *returned_bytes)
+{
+	/* No arbitration with VBIOS is performed since DCE 6.0 */
+	return I2C_CHANNEL_OPERATION_SUCCEEDED;
+}
+static bool get_hw_supported_ddc_line(
+	struct ddc *ddc,
+	enum gpio_ddc_line *line)
+{
+	enum gpio_ddc_line line_found;
+
+	*line = GPIO_DDC_LINE_UNKNOWN;
+
+	if (!ddc) {
+		BREAK_TO_DEBUGGER();
+		return false;
+	}
+
+	if (!ddc->hw_info.hw_supported)
+		return false;
+
+	line_found = dal_ddc_get_line(ddc);
+
+	if (line_found >= GPIO_DDC_LINE_COUNT)
+		return false;
+
+	*line = line_found;
+
+	return true;
+}
+static bool wait_for_scl_high_sw(
+	struct dc_context *ctx,
+	struct ddc *ddc,
+	uint16_t clock_delay_div_4)
+{
+	uint32_t scl_retry = 0;
+	uint32_t scl_retry_max = I2C_SW_TIMEOUT_DELAY / clock_delay_div_4;
+
+	udelay(clock_delay_div_4);
+
+	do {
+		if (read_bit_from_ddc(ddc, SCL))
+			return true;
+
+		udelay(clock_delay_div_4);
+
+		++scl_retry;
+	} while (scl_retry <= scl_retry_max);
+
+	return false;
+}
+static bool write_byte_sw(
+	struct dc_context *ctx,
+	struct ddc *ddc_handle,
+	uint16_t clock_delay_div_4,
+	uint8_t byte)
+{
+	int32_t shift = 7;
+	bool ack;
+
+	/* bits are transmitted serially, starting from MSB */
+
+	do {
+		udelay(clock_delay_div_4);
+
+		write_bit_to_ddc(ddc_handle, SDA, (byte >> shift) & 1);
+
+		udelay(clock_delay_div_4);
+
+		write_bit_to_ddc(ddc_handle, SCL, true);
+
+		if (!wait_for_scl_high_sw(ctx, ddc_handle, clock_delay_div_4))
+			return false;
+
+		write_bit_to_ddc(ddc_handle, SCL, false);
+
+		--shift;
+	} while (shift >= 0);
+
+	/* The display sends ACK by preventing the SDA from going high
+	 * after the SCL pulse we use to send our last data bit.
+	 * If the SDA goes high after that bit, it's a NACK
+	 */
+
+	udelay(clock_delay_div_4);
+
+	write_bit_to_ddc(ddc_handle, SDA, true);
+
+	udelay(clock_delay_div_4);
+
+	write_bit_to_ddc(ddc_handle, SCL, true);
+
+	if (!wait_for_scl_high_sw(ctx, ddc_handle, clock_delay_div_4))
+		return false;
+
+	/* read ACK bit */
+
+	ack = !read_bit_from_ddc(ddc_handle, SDA);
+
+	udelay(clock_delay_div_4 << 1);
+
+	write_bit_to_ddc(ddc_handle, SCL, false);
+
+	udelay(clock_delay_div_4 << 1);
+
+	return ack;
+}
+
+static bool read_byte_sw(
+	struct dc_context *ctx,
+	struct ddc *ddc_handle,
+	uint16_t clock_delay_div_4,
+	uint8_t *byte,
+	bool more)
+{
+	int32_t shift = 7;
+
+	uint8_t data = 0;
+
+	/* The data bits are read from MSB to LSB;
+	 * bit is read while SCL is high
+	 */
+
+	do {
+		write_bit_to_ddc(ddc_handle, SCL, true);
+
+		if (!wait_for_scl_high_sw(ctx, ddc_handle, clock_delay_div_4))
+			return false;
+
+		if (read_bit_from_ddc(ddc_handle, SDA))
+			data |= (1 << shift);
+
+		write_bit_to_ddc(ddc_handle, SCL, false);
+
+		udelay(clock_delay_div_4 << 1);
+
+		--shift;
+	} while (shift >= 0);
+
+	/* read only whole byte */
+
+	*byte = data;
+
+	udelay(clock_delay_div_4);
+
+	/* send the acknowledge bit:
+	 * SDA low means ACK, SDA high means NACK
+	 */
+
+	write_bit_to_ddc(ddc_handle, SDA, !more);
+
+	udelay(clock_delay_div_4);
+
+	write_bit_to_ddc(ddc_handle, SCL, true);
+
+	if (!wait_for_scl_high_sw(ctx, ddc_handle, clock_delay_div_4))
+		return false;
+
+	write_bit_to_ddc(ddc_handle, SCL, false);
+
+	udelay(clock_delay_div_4);
+
+	write_bit_to_ddc(ddc_handle, SDA, true);
+
+	udelay(clock_delay_div_4);
+
+	return true;
+}
+static bool stop_sync_sw(
+	struct dc_context *ctx,
+	struct ddc *ddc_handle,
+	uint16_t clock_delay_div_4)
+{
+	uint32_t retry = 0;
+
+	/* The I2C communications stop signal is:
+	 * the SDA going high from low, while the SCL is high.
+	 */
+
+	write_bit_to_ddc(ddc_handle, SCL, false);
+
+	udelay(clock_delay_div_4);
+
+	write_bit_to_ddc(ddc_handle, SDA, false);
+
+	udelay(clock_delay_div_4);
+
+	write_bit_to_ddc(ddc_handle, SCL, true);
+
+	if (!wait_for_scl_high_sw(ctx, ddc_handle, clock_delay_div_4))
+		return false;
+
+	write_bit_to_ddc(ddc_handle, SDA, true);
+
+	do {
+		udelay(clock_delay_div_4);
+
+		if (read_bit_from_ddc(ddc_handle, SDA))
+			return true;
+
+		++retry;
+	} while (retry <= 2);
+
+	return false;
+}
+static bool i2c_write_sw(
+	struct dc_context *ctx,
+	struct ddc *ddc_handle,
+	uint16_t clock_delay_div_4,
+	uint8_t address,
+	uint32_t length,
+	const uint8_t *data)
+{
+	uint32_t i = 0;
+
+	if (!write_byte_sw(ctx, ddc_handle, clock_delay_div_4, address))
+		return false;
+
+	while (i < length) {
+		if (!write_byte_sw(ctx, ddc_handle, clock_delay_div_4, data[i]))
+			return false;
+		++i;
+	}
+
+	return true;
+}
+
+static bool i2c_read_sw(
+	struct dc_context *ctx,
+	struct ddc *ddc_handle,
+	uint16_t clock_delay_div_4,
+	uint8_t address,
+	uint32_t length,
+	uint8_t *data)
+{
+	uint32_t i = 0;
+
+	if (!write_byte_sw(ctx, ddc_handle, clock_delay_div_4, address))
+		return false;
+
+	while (i < length) {
+		if (!read_byte_sw(ctx, ddc_handle, clock_delay_div_4, data + i,
+			i < length - 1))
+			return false;
+		++i;
+	}
+
+	return true;
+}
+
+
+
+static bool start_sync_sw(
+	struct dc_context *ctx,
+	struct ddc *ddc_handle,
+	uint16_t clock_delay_div_4)
+{
+	uint32_t retry = 0;
+
+	/* The I2C communications start signal is:
+	 * the SDA going low from high, while the SCL is high.
+	 */
+
+	write_bit_to_ddc(ddc_handle, SCL, true);
+
+	udelay(clock_delay_div_4);
+
+	do {
+		write_bit_to_ddc(ddc_handle, SDA, true);
+
+		if (!read_bit_from_ddc(ddc_handle, SDA)) {
+			++retry;
+			continue;
+		}
+
+		udelay(clock_delay_div_4);
+
+		write_bit_to_ddc(ddc_handle, SCL, true);
+
+		if (!wait_for_scl_high_sw(ctx, ddc_handle, clock_delay_div_4))
+			break;
+
+		write_bit_to_ddc(ddc_handle, SDA, false);
+
+		udelay(clock_delay_div_4);
+
+		write_bit_to_ddc(ddc_handle, SCL, false);
+
+		udelay(clock_delay_div_4);
+
+		return true;
+	} while (retry <= I2C_SW_RETRIES);
+
+	return false;
+}
+
+void dce_i2c_sw_engine_set_speed(
+	struct dce_i2c_sw *engine,
+	uint32_t speed)
+{
+	ASSERT(speed);
+
+	engine->speed = speed ? speed : DCE_I2C_DEFAULT_I2C_SW_SPEED;
+
+	engine->clock_delay = 1000 / engine->speed;
+
+	if (engine->clock_delay < 12)
+		engine->clock_delay = 12;
+}
+
+bool dce_i2c_sw_engine_acquire_engine(
+	struct dce_i2c_sw *engine,
+	struct ddc *ddc)
+{
+	enum gpio_result result;
+
+	result = dal_ddc_open(ddc, GPIO_MODE_FAST_OUTPUT,
+		GPIO_DDC_CONFIG_TYPE_MODE_I2C);
+
+	if (result != GPIO_RESULT_OK)
+		return false;
+
+	engine->ddc = ddc;
+
+	return true;
+}
+bool dce_i2c_engine_acquire_sw(
+	struct dce_i2c_sw *dce_i2c_sw,
+	struct ddc *ddc_handle)
+{
+	uint32_t counter = 0;
+	bool result;
+
+	do {
+
+		result = dce_i2c_sw_engine_acquire_engine(
+				dce_i2c_sw, ddc_handle);
+
+		if (result)
+			break;
+
+		/* i2c_engine is busy by VBios, lets wait and retry */
+
+		udelay(10);
+
+		++counter;
+	} while (counter < 2);
+
+	return result;
+}
+
+
+
+
+void dce_i2c_sw_engine_submit_channel_request(
+	struct dce_i2c_sw *engine,
+	struct i2c_request_transaction_data *req)
+{
+	struct ddc *ddc = engine->ddc;
+	uint16_t clock_delay_div_4 = engine->clock_delay >> 2;
+
+	/* send sync (start / repeated start) */
+
+	bool result = start_sync_sw(engine->ctx, ddc, clock_delay_div_4);
+
+	/* process payload */
+
+	if (result) {
+		switch (req->action) {
+		case DCE_I2C_TRANSACTION_ACTION_I2C_WRITE:
+		case DCE_I2C_TRANSACTION_ACTION_I2C_WRITE_MOT:
+			result = i2c_write_sw(engine->ctx, ddc, clock_delay_div_4,
+				req->address, req->length, req->data);
+		break;
+		case DCE_I2C_TRANSACTION_ACTION_I2C_READ:
+		case DCE_I2C_TRANSACTION_ACTION_I2C_READ_MOT:
+			result = i2c_read_sw(engine->ctx, ddc, clock_delay_div_4,
+				req->address, req->length, req->data);
+		break;
+		default:
+			result = false;
+		break;
+		}
+	}
+
+	/* send stop if not 'mot' or operation failed */
+
+	if (!result ||
+		(req->action == DCE_I2C_TRANSACTION_ACTION_I2C_WRITE) ||
+		(req->action == DCE_I2C_TRANSACTION_ACTION_I2C_READ))
+		if (!stop_sync_sw(engine->ctx, ddc, clock_delay_div_4))
+			result = false;
+
+	req->status = result ?
+		I2C_CHANNEL_OPERATION_SUCCEEDED :
+		I2C_CHANNEL_OPERATION_FAILED;
+}
+bool dce_i2c_sw_engine_submit_request(
+	struct dce_i2c_sw *engine,
+	struct dce_i2c_transaction_request *dce_i2c_request,
+	bool middle_of_transaction)
+{
+	struct i2c_request_transaction_data request;
+	bool operation_succeeded = false;
+
+	if (dce_i2c_request->operation == DCE_I2C_TRANSACTION_READ)
+		request.action = middle_of_transaction ?
+			DCE_I2C_TRANSACTION_ACTION_I2C_READ_MOT :
+			DCE_I2C_TRANSACTION_ACTION_I2C_READ;
+	else if (dce_i2c_request->operation == DCE_I2C_TRANSACTION_WRITE)
+		request.action = middle_of_transaction ?
+			DCE_I2C_TRANSACTION_ACTION_I2C_WRITE_MOT :
+			DCE_I2C_TRANSACTION_ACTION_I2C_WRITE;
+	else {
+		dce_i2c_request->status =
+			DCE_I2C_TRANSACTION_STATUS_FAILED_INVALID_OPERATION;
+		/* in DAL2, there was no "return false" */
+		return false;
+	}
+
+	request.address = (uint8_t)dce_i2c_request->payload.address;
+	request.length = dce_i2c_request->payload.length;
+	request.data = dce_i2c_request->payload.data;
+
+	dce_i2c_sw_engine_submit_channel_request(engine, &request);
+
+	if ((request.status == I2C_CHANNEL_OPERATION_ENGINE_BUSY) ||
+		(request.status == I2C_CHANNEL_OPERATION_FAILED))
+		dce_i2c_request->status =
+			DCE_I2C_TRANSACTION_STATUS_FAILED_CHANNEL_BUSY;
+	else {
+		enum i2c_channel_operation_result operation_result;
+
+		do {
+			operation_result =
+				dce_i2c_sw_engine_get_channel_status(engine, NULL);
+
+			switch (operation_result) {
+			case I2C_CHANNEL_OPERATION_SUCCEEDED:
+				dce_i2c_request->status =
+					DCE_I2C_TRANSACTION_STATUS_SUCCEEDED;
+				operation_succeeded = true;
+			break;
+			case I2C_CHANNEL_OPERATION_NO_RESPONSE:
+				dce_i2c_request->status =
+					DCE_I2C_TRANSACTION_STATUS_FAILED_NACK;
+			break;
+			case I2C_CHANNEL_OPERATION_TIMEOUT:
+				dce_i2c_request->status =
+				DCE_I2C_TRANSACTION_STATUS_FAILED_TIMEOUT;
+			break;
+			case I2C_CHANNEL_OPERATION_FAILED:
+				dce_i2c_request->status =
+				DCE_I2C_TRANSACTION_STATUS_FAILED_INCOMPLETE;
+			break;
+			default:
+				dce_i2c_request->status =
+				DCE_I2C_TRANSACTION_STATUS_FAILED_OPERATION;
+			break;
+			}
+		} while (operation_result == I2C_CHANNEL_OPERATION_ENGINE_BUSY);
+	}
+
+	return operation_succeeded;
+}
+bool dce_i2c_submit_command_sw(
+	struct resource_pool *pool,
+	struct ddc *ddc,
+	struct i2c_command *cmd,
+	struct dce_i2c_sw *dce_i2c_sw)
+{
+	uint8_t index_of_payload = 0;
+	bool result;
+
+	dce_i2c_sw_engine_set_speed(dce_i2c_sw, cmd->speed);
+
+	result = true;
+
+	while (index_of_payload < cmd->number_of_payloads) {
+		bool mot = (index_of_payload != cmd->number_of_payloads - 1);
+
+		struct i2c_payload *payload = cmd->payloads + index_of_payload;
+
+		struct dce_i2c_transaction_request request = { 0 };
+
+		request.operation = payload->write ?
+			DCE_I2C_TRANSACTION_WRITE :
+			DCE_I2C_TRANSACTION_READ;
+
+		request.payload.address_space =
+			DCE_I2C_TRANSACTION_ADDRESS_SPACE_I2C;
+		request.payload.address = (payload->address << 1) |
+			!payload->write;
+		request.payload.length = payload->length;
+		request.payload.data = payload->data;
+
+
+		if (!dce_i2c_sw_engine_submit_request(
+			dce_i2c_sw, &request, mot)) {
+			result = false;
+			break;
+		}
+
+		++index_of_payload;
+	}
+
+	release_engine_dce_sw(pool, dce_i2c_sw);
+
+	return result;
+}
+struct dce_i2c_sw *dce_i2c_acquire_i2c_sw_engine(
+	struct resource_pool *pool,
+	struct ddc *ddc)
+{
+	enum gpio_ddc_line line;
+	struct dce_i2c_sw *engine = NULL;
+
+	if (get_hw_supported_ddc_line(ddc, &line))
+		engine = pool->sw_i2cs[line];
+
+	if (!engine)
+		return NULL;
+
+	if (!dce_i2c_engine_acquire_sw(engine, ddc))
+		return NULL;
+
+	return engine;
+}

drivers/gpu/drm/amd/display/dc/dce/dce_i2c_sw.h

+/*
+ * Copyright 2018 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 __DCE_I2C_SW_H__
+#define __DCE_I2C_SW_H__
+
+enum {
+	DCE_I2C_DEFAULT_I2C_SW_SPEED = 50,
+	I2C_SW_RETRIES = 10,
+	I2C_SW_TIMEOUT_DELAY = 3000,
+};
+
+struct dce_i2c_sw {
+	struct ddc *ddc;
+	struct dc_context *ctx;
+	uint32_t clock_delay;
+	uint32_t speed;
+};
+
+void dce_i2c_sw_construct(
+	struct dce_i2c_sw *dce_i2c_sw,
+	struct dc_context *ctx);
+
+bool dce_i2c_submit_command_sw(
+	struct resource_pool *pool,
+	struct ddc *ddc,
+	struct i2c_command *cmd,
+	struct dce_i2c_sw *dce_i2c_sw);
+
+struct dce_i2c_sw *dce_i2c_acquire_i2c_sw_engine(
+	struct resource_pool *pool,
+	struct ddc *ddc);
+
+#endif
+

drivers/gpu/drm/amd/display/dc/dce100/dce100_resource.c

@@ -54,6 +54,7 @@
 #include "dce/dce_dmcu.h"
 #include "dce/dce_aux.h"
 #include "dce/dce_abm.h"
+#include "dce/dce_i2c.h"
 
 #ifndef mmMC_HUB_RDREQ_DMIF_LIMIT
 #include "gmc/gmc_8_2_d.h"
@@ -602,7 +603,40 @@ struct aux_engine *dce100_aux_engine_create(
 
 	return &aux_engine->base;
 }
+#define i2c_inst_regs(id) { I2C_HW_ENGINE_COMMON_REG_LIST(id) }
+
+static const struct dce_i2c_registers i2c_hw_regs[] = {
+		i2c_inst_regs(1),
+		i2c_inst_regs(2),
+		i2c_inst_regs(3),
+		i2c_inst_regs(4),
+		i2c_inst_regs(5),
+		i2c_inst_regs(6),
+};
+
+static const struct dce_i2c_shift i2c_shifts = {
+		I2C_COMMON_MASK_SH_LIST_DCE_COMMON_BASE(__SHIFT)
+};
+
+static const struct dce_i2c_mask i2c_masks = {
+		I2C_COMMON_MASK_SH_LIST_DCE_COMMON_BASE(_MASK)
+};
+
+struct dce_i2c_hw *dce100_i2c_hw_create(
+	struct dc_context *ctx,
+	uint32_t inst)
+{
+	struct dce_i2c_hw *dce_i2c_hw =
+		kzalloc(sizeof(struct dce_i2c_hw), GFP_KERNEL);
+
+	if (!dce_i2c_hw)
+		return NULL;
+
+	dce100_i2c_hw_construct(dce_i2c_hw, ctx, inst,
+				    &i2c_hw_regs[inst], &i2c_shifts, &i2c_masks);
 
+	return dce_i2c_hw;
+}
 struct clock_source *dce100_clock_source_create(
 	struct dc_context *ctx,
 	struct dc_bios *bios,
@@ -658,7 +692,14 @@ static void destruct(struct dce110_resource_pool *pool)
 
 		if (pool->base.engines[i] != NULL)
 			dce110_engine_destroy(&pool->base.engines[i]);
-
+		if (pool->base.hw_i2cs[i] != NULL) {
+			kfree(pool->base.hw_i2cs[i]);
+			pool->base.hw_i2cs[i] = NULL;
+		}
+		if (pool->base.sw_i2cs[i] != NULL) {
+			kfree(pool->base.sw_i2cs[i]);
+			pool->base.sw_i2cs[i] = NULL;
+		}
 	}
 
 	for (i = 0; i < pool->base.stream_enc_count; i++) {
@@ -970,6 +1011,14 @@ static bool construct(
 				"DC:failed to create aux engine!!\n");
 			goto res_create_fail;
 		}
+		pool->base.hw_i2cs[i] = dce100_i2c_hw_create(ctx, i);
+		if (pool->base.hw_i2cs[i] == NULL) {
+			BREAK_TO_DEBUGGER();
+			dm_error(
+				"DC:failed to create i2c engine!!\n");
+			goto res_create_fail;
+		}
+		pool->base.sw_i2cs[i] = NULL;
 	}
 
 	dc->caps.max_planes =  pool->base.pipe_count;

drivers/gpu/drm/amd/display/dc/dce110/dce110_resource.c

@@ -52,6 +52,7 @@
 #include "dce/dce_aux.h"
 #include "dce/dce_abm.h"
 #include "dce/dce_dmcu.h"
+#include "dce/dce_i2c.h"
 
 #define DC_LOGGER \
 		dc->ctx->logger
@@ -620,7 +621,40 @@ struct aux_engine *dce110_aux_engine_create(
 
 	return &aux_engine->base;
 }
+#define i2c_inst_regs(id) { I2C_HW_ENGINE_COMMON_REG_LIST(id) }
+
+static const struct dce_i2c_registers i2c_hw_regs[] = {
+		i2c_inst_regs(1),
+		i2c_inst_regs(2),
+		i2c_inst_regs(3),
+		i2c_inst_regs(4),
+		i2c_inst_regs(5),
+		i2c_inst_regs(6),
+};
+
+static const struct dce_i2c_shift i2c_shifts = {
+		I2C_COMMON_MASK_SH_LIST_DCE110(__SHIFT)
+};
+
+static const struct dce_i2c_mask i2c_masks = {
+		I2C_COMMON_MASK_SH_LIST_DCE110(_MASK)
+};
+
+struct dce_i2c_hw *dce110_i2c_hw_create(
+	struct dc_context *ctx,
+	uint32_t inst)
+{
+	struct dce_i2c_hw *dce_i2c_hw =
+		kzalloc(sizeof(struct dce_i2c_hw), GFP_KERNEL);
+
+	if (!dce_i2c_hw)
+		return NULL;
+
+	dce100_i2c_hw_construct(dce_i2c_hw, ctx, inst,
+				    &i2c_hw_regs[inst], &i2c_shifts, &i2c_masks);
 
+	return dce_i2c_hw;
+}
 struct clock_source *dce110_clock_source_create(
 	struct dc_context *ctx,
 	struct dc_bios *bios,
@@ -687,7 +721,14 @@ static void destruct(struct dce110_resource_pool *pool)
 
 		if (pool->base.engines[i] != NULL)
 			dce110_engine_destroy(&pool->base.engines[i]);
-
+		if (pool->base.hw_i2cs[i] != NULL) {
+			kfree(pool->base.hw_i2cs[i]);
+			pool->base.hw_i2cs[i] = NULL;
+		}
+		if (pool->base.sw_i2cs[i] != NULL) {
+			kfree(pool->base.sw_i2cs[i]);
+			pool->base.sw_i2cs[i] = NULL;
+		}
 	}
 
 	for (i = 0; i < pool->base.stream_enc_count; i++) {
@@ -1303,6 +1344,14 @@ static bool construct(
 				"DC:failed to create aux engine!!\n");
 			goto res_create_fail;
 		}
+		pool->base.hw_i2cs[i] = dce110_i2c_hw_create(ctx, i);
+		if (pool->base.hw_i2cs[i] == NULL) {
+			BREAK_TO_DEBUGGER();
+			dm_error(
+				"DC:failed to create i2c engine!!\n");
+			goto res_create_fail;
+		}
+		pool->base.sw_i2cs[i] = NULL;
 	}
 
 	dc->fbc_compressor = dce110_compressor_create(ctx);

drivers/gpu/drm/amd/display/dc/dce112/dce112_resource.c

@@ -50,6 +50,7 @@
 #include "dce/dce_abm.h"
 #include "dce/dce_dmcu.h"
 #include "dce/dce_aux.h"
+#include "dce/dce_i2c.h"
 
 #include "reg_helper.h"
 
@@ -620,7 +621,40 @@ struct aux_engine *dce112_aux_engine_create(
 
 	return &aux_engine->base;
 }
+#define i2c_inst_regs(id) { I2C_HW_ENGINE_COMMON_REG_LIST(id) }
+
+static const struct dce_i2c_registers i2c_hw_regs[] = {
+		i2c_inst_regs(1),
+		i2c_inst_regs(2),
+		i2c_inst_regs(3),
+		i2c_inst_regs(4),
+		i2c_inst_regs(5),
+		i2c_inst_regs(6),
+};
+
+static const struct dce_i2c_shift i2c_shifts = {
+		I2C_COMMON_MASK_SH_LIST_DCE110(__SHIFT)
+};
+
+static const struct dce_i2c_mask i2c_masks = {
+		I2C_COMMON_MASK_SH_LIST_DCE110(_MASK)
+};
+
+struct dce_i2c_hw *dce112_i2c_hw_create(
+	struct dc_context *ctx,
+	uint32_t inst)
+{
+	struct dce_i2c_hw *dce_i2c_hw =
+		kzalloc(sizeof(struct dce_i2c_hw), GFP_KERNEL);
+
+	if (!dce_i2c_hw)
+		return NULL;
+
+	dce112_i2c_hw_construct(dce_i2c_hw, ctx, inst,
+				    &i2c_hw_regs[inst], &i2c_shifts, &i2c_masks);
 
+	return dce_i2c_hw;
+}
 struct clock_source *dce112_clock_source_create(
 	struct dc_context *ctx,
 	struct dc_bios *bios,
@@ -676,7 +710,14 @@ static void destruct(struct dce110_resource_pool *pool)
 			kfree(DCE110TG_FROM_TG(pool->base.timing_generators[i]));
 			pool->base.timing_generators[i] = NULL;
 		}
-
+		if (pool->base.hw_i2cs[i] != NULL) {
+			kfree(pool->base.hw_i2cs[i]);
+			pool->base.hw_i2cs[i] = NULL;
+		}
+		if (pool->base.sw_i2cs[i] != NULL) {
+			kfree(pool->base.sw_i2cs[i]);
+			pool->base.sw_i2cs[i] = NULL;
+		}
 	}
 
 	for (i = 0; i < pool->base.stream_enc_count; i++) {
@@ -1252,6 +1293,14 @@ static bool construct(
 				"DC:failed to create aux engine!!\n");
 			goto res_create_fail;
 		}
+		pool->base.hw_i2cs[i] = dce112_i2c_hw_create(ctx, i);
+		if (pool->base.hw_i2cs[i] == NULL) {
+			BREAK_TO_DEBUGGER();
+			dm_error(
+				"DC:failed to create i2c engine!!\n");
+			goto res_create_fail;
+		}
+		pool->base.sw_i2cs[i] = NULL;
 	}
 
 	if (!resource_construct(num_virtual_links, dc, &pool->base,

drivers/gpu/drm/amd/display/dc/dce120/dce120_resource.c

@@ -54,6 +54,7 @@
 #include "dce/dce_abm.h"
 #include "dce/dce_dmcu.h"
 #include "dce/dce_aux.h"
+#include "dce/dce_i2c.h"
 
 #include "dce/dce_12_0_offset.h"
 #include "dce/dce_12_0_sh_mask.h"
@@ -392,7 +393,40 @@ struct aux_engine *dce120_aux_engine_create(
 
 	return &aux_engine->base;
 }
+#define i2c_inst_regs(id) { I2C_HW_ENGINE_COMMON_REG_LIST(id) }
+
+static const struct dce_i2c_registers i2c_hw_regs[] = {
+		i2c_inst_regs(1),
+		i2c_inst_regs(2),
+		i2c_inst_regs(3),
+		i2c_inst_regs(4),
+		i2c_inst_regs(5),
+		i2c_inst_regs(6),
+};
+
+static const struct dce_i2c_shift i2c_shifts = {
+		I2C_COMMON_MASK_SH_LIST_DCE110(__SHIFT)
+};
 
+static const struct dce_i2c_mask i2c_masks = {
+		I2C_COMMON_MASK_SH_LIST_DCE110(_MASK)
+};
+
+struct dce_i2c_hw *dce120_i2c_hw_create(
+	struct dc_context *ctx,
+	uint32_t inst)
+{
+	struct dce_i2c_hw *dce_i2c_hw =
+		kzalloc(sizeof(struct dce_i2c_hw), GFP_KERNEL);
+
+	if (!dce_i2c_hw)
+		return NULL;
+
+	dce112_i2c_hw_construct(dce_i2c_hw, ctx, inst,
+				    &i2c_hw_regs[inst], &i2c_shifts, &i2c_masks);
+
+	return dce_i2c_hw;
+}
 static const struct bios_registers bios_regs = {
 	.BIOS_SCRATCH_6 = mmBIOS_SCRATCH_6 + NBIO_BASE(mmBIOS_SCRATCH_6_BASE_IDX)
 };
@@ -501,7 +535,14 @@ static void destruct(struct dce110_resource_pool *pool)
 
 		if (pool->base.engines[i] != NULL)
 			dce110_engine_destroy(&pool->base.engines[i]);
-
+		if (pool->base.hw_i2cs[i] != NULL) {
+			kfree(pool->base.hw_i2cs[i]);
+			pool->base.hw_i2cs[i] = NULL;
+		}
+		if (pool->base.sw_i2cs[i] != NULL) {
+			kfree(pool->base.sw_i2cs[i]);
+			pool->base.sw_i2cs[i] = NULL;
+		}
 	}
 
 	for (i = 0; i < pool->base.audio_count; i++) {
@@ -957,6 +998,7 @@ static bool construct(
 		goto res_create_fail;
 	}
 
+
 	irq_init_data.ctx = dc->ctx;
 	pool->base.irqs = dal_irq_service_dce120_create(&irq_init_data);
 	if (!pool->base.irqs)
@@ -1021,13 +1063,20 @@ static bool construct(
 				"DC: failed to create output pixel processor!\n");
 		}
 		pool->base.engines[i] = dce120_aux_engine_create(ctx, i);
-				if (pool->base.engines[i] == NULL) {
-					BREAK_TO_DEBUGGER();
-					dm_error(
-						"DC:failed to create aux engine!!\n");
-					goto res_create_fail;
-				}
-
+		if (pool->base.engines[i] == NULL) {
+			BREAK_TO_DEBUGGER();
+			dm_error(
+				"DC:failed to create aux engine!!\n");
+			goto res_create_fail;
+		}
+		pool->base.hw_i2cs[i] = dce120_i2c_hw_create(ctx, i);
+		if (pool->base.hw_i2cs[i] == NULL) {
+			BREAK_TO_DEBUGGER();
+			dm_error(
+				"DC:failed to create i2c engine!!\n");
+			goto res_create_fail;
+		}
+		pool->base.sw_i2cs[i] = NULL;
 		/* check next valid pipe */
 		j++;
 	}

drivers/gpu/drm/amd/display/dc/dce80/dce80_resource.c

@@ -56,6 +56,7 @@
 #include "dce/dce_dmcu.h"
 #include "dce/dce_aux.h"
 #include "dce/dce_abm.h"
+#include "dce/dce_i2c.h"
 /* TODO remove this include */
 
 #ifndef mmMC_HUB_RDREQ_DMIF_LIMIT
@@ -480,7 +481,54 @@ struct aux_engine *dce80_aux_engine_create(
 
 	return &aux_engine->base;
 }
+#define i2c_inst_regs(id) { I2C_HW_ENGINE_COMMON_REG_LIST(id) }
+
+static const struct dce_i2c_registers i2c_hw_regs[] = {
+		i2c_inst_regs(1),
+		i2c_inst_regs(2),
+		i2c_inst_regs(3),
+		i2c_inst_regs(4),
+		i2c_inst_regs(5),
+		i2c_inst_regs(6),
+};
+
+static const struct dce_i2c_shift i2c_shifts = {
+		I2C_COMMON_MASK_SH_LIST_DCE_COMMON_BASE(__SHIFT)
+};
+
+static const struct dce_i2c_mask i2c_masks = {
+		I2C_COMMON_MASK_SH_LIST_DCE_COMMON_BASE(_MASK)
+};
+
+struct dce_i2c_hw *dce80_i2c_hw_create(
+	struct dc_context *ctx,
+	uint32_t inst)
+{
+	struct dce_i2c_hw *dce_i2c_hw =
+		kzalloc(sizeof(struct dce_i2c_hw), GFP_KERNEL);
+
+	if (!dce_i2c_hw)
+		return NULL;
+
+	dce_i2c_hw_construct(dce_i2c_hw, ctx, inst,
+				    &i2c_hw_regs[inst], &i2c_shifts, &i2c_masks);
 
+	return dce_i2c_hw;
+}
+
+struct dce_i2c_sw *dce80_i2c_sw_create(
+	struct dc_context *ctx)
+{
+	struct dce_i2c_sw *dce_i2c_sw =
+		kzalloc(sizeof(struct dce_i2c_sw), GFP_KERNEL);
+
+	if (!dce_i2c_sw)
+		return NULL;
+
+	dce_i2c_sw_construct(dce_i2c_sw, ctx);
+
+	return dce_i2c_sw;
+}
 static struct stream_encoder *dce80_stream_encoder_create(
 	enum engine_id eng_id,
 	struct dc_context *ctx)
@@ -691,6 +739,14 @@ static void destruct(struct dce110_resource_pool *pool)
 
 		if (pool->base.engines[i] != NULL)
 			dce110_engine_destroy(&pool->base.engines[i]);
+		if (pool->base.hw_i2cs[i] != NULL) {
+			kfree(pool->base.hw_i2cs[i]);
+			pool->base.hw_i2cs[i] = NULL;
+		}
+		if (pool->base.sw_i2cs[i] != NULL) {
+			kfree(pool->base.sw_i2cs[i]);
+			pool->base.sw_i2cs[i] = NULL;
+		}
 	}
 
 	for (i = 0; i < pool->base.stream_enc_count; i++) {
@@ -887,6 +943,7 @@ static bool dce80_construct(
 		BREAK_TO_DEBUGGER();
 		goto res_create_fail;
 	}
+
 	if (dm_pp_get_static_clocks(ctx, &static_clk_info))
 		pool->base.dccg->max_clks_state =
 					static_clk_info.max_clocks_state;
@@ -943,6 +1000,20 @@ static bool dce80_construct(
 				"DC:failed to create aux engine!!\n");
 			goto res_create_fail;
 		}
+		pool->base.hw_i2cs[i] = dce80_i2c_hw_create(ctx, i);
+		if (pool->base.hw_i2cs[i] == NULL) {
+			BREAK_TO_DEBUGGER();
+			dm_error(
+				"DC:failed to create i2c engine!!\n");
+			goto res_create_fail;
+		}
+		pool->base.sw_i2cs[i] = dce80_i2c_sw_create(ctx);
+		if (pool->base.sw_i2cs[i] == NULL) {
+			BREAK_TO_DEBUGGER();
+			dm_error(
+				"DC:failed to create sw i2c!!\n");
+			goto res_create_fail;
+		}
 	}
 
 	dc->caps.max_planes =  pool->base.pipe_count;
@@ -1129,6 +1200,20 @@ static bool dce81_construct(
 			dm_error("DC: failed to create output pixel processor!\n");
 			goto res_create_fail;
 		}
+		pool->base.hw_i2cs[i] = dce80_i2c_hw_create(ctx, i);
+		if (pool->base.hw_i2cs[i] == NULL) {
+			BREAK_TO_DEBUGGER();
+			dm_error(
+				"DC:failed to create i2c engine!!\n");
+			goto res_create_fail;
+		}
+		pool->base.sw_i2cs[i] = dce80_i2c_sw_create(ctx);
+		if (pool->base.sw_i2cs[i] == NULL) {
+			BREAK_TO_DEBUGGER();
+			dm_error(
+				"DC:failed to create sw i2c!!\n");
+			goto res_create_fail;
+		}
 	}
 
 	dc->caps.max_planes =  pool->base.pipe_count;
@@ -1311,6 +1396,20 @@ static bool dce83_construct(
 			dm_error("DC: failed to create output pixel processor!\n");
 			goto res_create_fail;
 		}
+		pool->base.hw_i2cs[i] = dce80_i2c_hw_create(ctx, i);
+		if (pool->base.hw_i2cs[i] == NULL) {
+			BREAK_TO_DEBUGGER();
+			dm_error(
+				"DC:failed to create i2c engine!!\n");
+			goto res_create_fail;
+		}
+		pool->base.sw_i2cs[i] = dce80_i2c_sw_create(ctx);
+		if (pool->base.sw_i2cs[i] == NULL) {
+			BREAK_TO_DEBUGGER();
+			dm_error(
+				"DC:failed to create sw i2c!!\n");
+			goto res_create_fail;
+		}
 	}
 
 	dc->caps.max_planes =  pool->base.pipe_count;

drivers/gpu/drm/amd/display/dc/dcn10/dcn10_resource.c

@@ -65,6 +65,7 @@
 #include "dce/dce_abm.h"
 #include "dce/dce_dmcu.h"
 #include "dce/dce_aux.h"
+#include "dce/dce_i2c.h"
 
 const struct _vcs_dpi_ip_params_st dcn1_0_ip = {
 	.rob_buffer_size_kbytes = 64,
@@ -610,7 +611,40 @@ struct aux_engine *dcn10_aux_engine_create(
 
 	return &aux_engine->base;
 }
+#define i2c_inst_regs(id) { I2C_HW_ENGINE_COMMON_REG_LIST(id) }
+
+static const struct dce_i2c_registers i2c_hw_regs[] = {
+		i2c_inst_regs(1),
+		i2c_inst_regs(2),
+		i2c_inst_regs(3),
+		i2c_inst_regs(4),
+		i2c_inst_regs(5),
+		i2c_inst_regs(6),
+};
+
+static const struct dce_i2c_shift i2c_shifts = {
+		I2C_COMMON_MASK_SH_LIST_DCE110(__SHIFT)
+};
+
+static const struct dce_i2c_mask i2c_masks = {
+		I2C_COMMON_MASK_SH_LIST_DCE110(_MASK)
+};
+
+struct dce_i2c_hw *dcn10_i2c_hw_create(
+	struct dc_context *ctx,
+	uint32_t inst)
+{
+	struct dce_i2c_hw *dce_i2c_hw =
+		kzalloc(sizeof(struct dce_i2c_hw), GFP_KERNEL);
+
+	if (!dce_i2c_hw)
+		return NULL;
+
+	dcn1_i2c_hw_construct(dce_i2c_hw, ctx, inst,
+				    &i2c_hw_regs[inst], &i2c_shifts, &i2c_masks);
 
+	return dce_i2c_hw;
+}
 static struct mpc *dcn10_mpc_create(struct dc_context *ctx)
 {
 	struct dcn10_mpc *mpc10 = kzalloc(sizeof(struct dcn10_mpc),
@@ -862,6 +896,14 @@ static void destruct(struct dcn10_resource_pool *pool)
 
 		if (pool->base.engines[i] != NULL)
 			pool->base.engines[i]->funcs->destroy_engine(&pool->base.engines[i]);
+		if (pool->base.hw_i2cs[i] != NULL) {
+			kfree(pool->base.hw_i2cs[i]);
+			pool->base.hw_i2cs[i] = NULL;
+		}
+		if (pool->base.sw_i2cs[i] != NULL) {
+			kfree(pool->base.sw_i2cs[i]);
+			pool->base.sw_i2cs[i] = NULL;
+		}
 	}
 
 	for (i = 0; i < pool->base.stream_enc_count; i++)
@@ -1300,7 +1342,14 @@ static bool construct(
 				"DC:failed to create aux engine!!\n");
 			goto fail;
 		}
-
+		pool->base.hw_i2cs[i] = dcn10_i2c_hw_create(ctx, i);
+		if (pool->base.hw_i2cs[i] == NULL) {
+			BREAK_TO_DEBUGGER();
+			dm_error(
+				"DC:failed to create hw i2c!!\n");
+			goto fail;
+		}
+		pool->base.sw_i2cs[i] = NULL;
 		/* check next valid pipe */
 		j++;
 	}

drivers/gpu/drm/amd/display/dc/inc/core_types.h

@@ -144,6 +144,9 @@ struct resource_pool {
 	struct mpc *mpc;
 	struct pp_smu_funcs_rv *pp_smu;
 	struct pp_smu_display_requirement_rv pp_smu_req;
+	struct dce_i2c_hw *hw_i2cs[MAX_PIPES];
+	struct dce_i2c_sw *sw_i2cs[MAX_PIPES];
+	bool i2c_hw_buffer_in_use;
 
 	unsigned int pipe_count;
 	unsigned int underlay_pipe_index;