1 files changed, 601 insertions, 0 deletions
diff --git a/drivers/gpu/drm/amd/display/dc/i2caux/i2c_sw_engine.c b/drivers/gpu/drm/amd/display/dc/i2caux/i2c_sw_engine.c
new file mode 100644
index 000000000000..8e19bb629394
--- /dev/null
+++ b/drivers/gpu/drm/amd/display/dc/i2caux/i2c_sw_engine.c
@@ -0,0 +1,601 @@
+/*
+ * Copyright 2012-15 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 "dm_services.h"
+
+/*
+ * Pre-requisites: headers required by header of this unit
+ */
+#include "include/i2caux_interface.h"
+#include "engine.h"
+#include "i2c_engine.h"
+
+/*
+ * Header of this unit
+ */
+
+#include "i2c_sw_engine.h"
+
+/*
+ * Post-requisites: headers required by this unit
+ */
+
+/*
+ * This unit
+ */
+
+#define SCL false
+#define SDA true
+
+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 bool wait_for_scl_high(
+	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);
+
+	/* 3 milliseconds delay
+	 * to wake up some displays from "low power" state.
+	 */
+
+	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 start_sync(
+	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(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;
+}
+
+static bool stop_sync(
+	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(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 write_byte(
+	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(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(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(
+	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(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(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 i2c_write(
+	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(ctx, ddc_handle, clock_delay_div_4, address))
+		return false;
+
+	while (i < length) {
+		if (!write_byte(ctx, ddc_handle, clock_delay_div_4, data[i]))
+			return false;
+		++i;
+	}
+
+	return true;
+}
+
+static bool i2c_read(
+	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(ctx, ddc_handle, clock_delay_div_4, address))
+		return false;
+
+	while (i < length) {
+		if (!read_byte(ctx, ddc_handle, clock_delay_div_4, data + i,
+			i < length - 1))
+			return false;
+		++i;
+	}
+
+	return true;
+}
+
+/*
+ * @brief
+ * Cast 'struct i2c_engine *'
+ * to 'struct i2c_sw_engine *'
+ */
+#define FROM_I2C_ENGINE(ptr) \
+	container_of((ptr), struct i2c_sw_engine, base)
+
+/*
+ * @brief
+ * Cast 'struct engine *'
+ * to 'struct i2c_sw_engine *'
+ */
+#define FROM_ENGINE(ptr) \
+	FROM_I2C_ENGINE(container_of((ptr), struct i2c_engine, base))
+
+enum i2caux_engine_type dal_i2c_sw_engine_get_engine_type(
+	const struct engine *engine)
+{
+	return I2CAUX_ENGINE_TYPE_I2C_SW;
+}
+
+bool dal_i2c_sw_engine_submit_request(
+	struct engine *engine,
+	struct i2caux_transaction_request *i2caux_request,
+	bool middle_of_transaction)
+{
+	struct i2c_sw_engine *sw_engine = FROM_ENGINE(engine);
+
+	struct i2c_engine *base = &sw_engine->base;
+
+	struct i2c_request_transaction_data request;
+	bool operation_succeeded = false;
+
+	if (i2caux_request->operation == I2CAUX_TRANSACTION_READ)
+		request.action = middle_of_transaction ?
+			I2CAUX_TRANSACTION_ACTION_I2C_READ_MOT :
+			I2CAUX_TRANSACTION_ACTION_I2C_READ;
+	else if (i2caux_request->operation == I2CAUX_TRANSACTION_WRITE)
+		request.action = middle_of_transaction ?
+			I2CAUX_TRANSACTION_ACTION_I2C_WRITE_MOT :
+			I2CAUX_TRANSACTION_ACTION_I2C_WRITE;
+	else {
+		i2caux_request->status =
+			I2CAUX_TRANSACTION_STATUS_FAILED_INVALID_OPERATION;
+		/* in DAL2, there was no "return false" */
+		return false;
+	}
+
+	request.address = (uint8_t)i2caux_request->payload.address;
+	request.length = i2caux_request->payload.length;
+	request.data = i2caux_request->payload.data;
+
+	base->funcs->submit_channel_request(base, &request);
+
+	if ((request.status == I2C_CHANNEL_OPERATION_ENGINE_BUSY) ||
+		(request.status == I2C_CHANNEL_OPERATION_FAILED))
+		i2caux_request->status =
+			I2CAUX_TRANSACTION_STATUS_FAILED_CHANNEL_BUSY;
+	else {
+		enum i2c_channel_operation_result operation_result;
+
+		do {
+			operation_result =
+				base->funcs->get_channel_status(base, NULL);
+
+			switch (operation_result) {
+			case I2C_CHANNEL_OPERATION_SUCCEEDED:
+				i2caux_request->status =
+					I2CAUX_TRANSACTION_STATUS_SUCCEEDED;
+				operation_succeeded = true;
+			break;
+			case I2C_CHANNEL_OPERATION_NO_RESPONSE:
+				i2caux_request->status =
+					I2CAUX_TRANSACTION_STATUS_FAILED_NACK;
+			break;
+			case I2C_CHANNEL_OPERATION_TIMEOUT:
+				i2caux_request->status =
+				I2CAUX_TRANSACTION_STATUS_FAILED_TIMEOUT;
+			break;
+			case I2C_CHANNEL_OPERATION_FAILED:
+				i2caux_request->status =
+				I2CAUX_TRANSACTION_STATUS_FAILED_INCOMPLETE;
+			break;
+			default:
+				i2caux_request->status =
+				I2CAUX_TRANSACTION_STATUS_FAILED_OPERATION;
+			break;
+			}
+		} while (operation_result == I2C_CHANNEL_OPERATION_ENGINE_BUSY);
+	}
+
+	return operation_succeeded;
+}
+
+uint32_t dal_i2c_sw_engine_get_speed(
+	const struct i2c_engine *engine)
+{
+	return FROM_I2C_ENGINE(engine)->speed;
+}
+
+void dal_i2c_sw_engine_set_speed(
+	struct i2c_engine *engine,
+	uint32_t speed)
+{
+	struct i2c_sw_engine *sw_engine = FROM_I2C_ENGINE(engine);
+
+	ASSERT(speed);
+
+	sw_engine->speed = speed ? speed : I2CAUX_DEFAULT_I2C_SW_SPEED;
+
+	sw_engine->clock_delay = 1000 / sw_engine->speed;
+
+	if (sw_engine->clock_delay < 12)
+		sw_engine->clock_delay = 12;
+}
+
+bool dal_i2caux_i2c_sw_engine_acquire_engine(
+	struct i2c_engine *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->base.ddc = ddc;
+
+	return true;
+}
+
+void dal_i2c_sw_engine_submit_channel_request(
+	struct i2c_engine *engine,
+	struct i2c_request_transaction_data *req)
+{
+	struct i2c_sw_engine *sw_engine = FROM_I2C_ENGINE(engine);
+
+	struct ddc *ddc = engine->base.ddc;
+	uint16_t clock_delay_div_4 = sw_engine->clock_delay >> 2;
+
+	/* send sync (start / repeated start) */
+
+	bool result = start_sync(engine->base.ctx, ddc, clock_delay_div_4);
+
+	/* process payload */
+
+	if (result) {
+		switch (req->action) {
+		case I2CAUX_TRANSACTION_ACTION_I2C_WRITE:
+		case I2CAUX_TRANSACTION_ACTION_I2C_WRITE_MOT:
+			result = i2c_write(engine->base.ctx, ddc, clock_delay_div_4,
+				req->address, req->length, req->data);
+		break;
+		case I2CAUX_TRANSACTION_ACTION_I2C_READ:
+		case I2CAUX_TRANSACTION_ACTION_I2C_READ_MOT:
+			result = i2c_read(engine->base.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 == I2CAUX_TRANSACTION_ACTION_I2C_WRITE) ||
+		(req->action == I2CAUX_TRANSACTION_ACTION_I2C_READ))
+		if (!stop_sync(engine->base.ctx, ddc, clock_delay_div_4))
+			result = false;
+
+	req->status = result ?
+		I2C_CHANNEL_OPERATION_SUCCEEDED :
+		I2C_CHANNEL_OPERATION_FAILED;
+}
+
+enum i2c_channel_operation_result dal_i2c_sw_engine_get_channel_status(
+	struct i2c_engine *engine,
+	uint8_t *returned_bytes)
+{
+	/* No arbitration with VBIOS is performed since DCE 6.0 */
+	return I2C_CHANNEL_OPERATION_SUCCEEDED;
+}
+
+void dal_i2c_sw_engine_destruct(
+	struct i2c_sw_engine *engine)
+{
+	dal_i2c_engine_destruct(&engine->base);
+}
+
+static void destroy(
+	struct i2c_engine **ptr)
+{
+	dal_i2c_sw_engine_destruct(FROM_I2C_ENGINE(*ptr));
+
+	kfree(*ptr);
+	*ptr = NULL;
+}
+
+static const struct i2c_engine_funcs i2c_engine_funcs = {
+	.acquire_engine = dal_i2caux_i2c_sw_engine_acquire_engine,
+	.destroy = destroy,
+	.get_speed = dal_i2c_sw_engine_get_speed,
+	.set_speed = dal_i2c_sw_engine_set_speed,
+	.setup_engine = dal_i2c_engine_setup_i2c_engine,
+	.submit_channel_request = dal_i2c_sw_engine_submit_channel_request,
+	.process_channel_reply = dal_i2c_engine_process_channel_reply,
+	.get_channel_status = dal_i2c_sw_engine_get_channel_status,
+};
+
+static void release_engine(
+	struct engine *engine)
+{
+
+}
+
+static const struct engine_funcs engine_funcs = {
+	.release_engine = release_engine,
+	.get_engine_type = dal_i2c_sw_engine_get_engine_type,
+	.acquire = dal_i2c_engine_acquire,
+	.submit_request = dal_i2c_sw_engine_submit_request,
+};
+
+void dal_i2c_sw_engine_construct(
+	struct i2c_sw_engine *engine,
+	const struct i2c_sw_engine_create_arg *arg)
+{
+	dal_i2c_engine_construct(&engine->base, arg->ctx);
+	dal_i2c_sw_engine_set_speed(&engine->base, arg->default_speed);
+	engine->base.funcs = &i2c_engine_funcs;
+	engine->base.base.funcs = &engine_funcs;
+}
+
+struct i2c_engine *dal_i2c_sw_engine_create(
+	const struct i2c_sw_engine_create_arg *arg)
+{
+	struct i2c_sw_engine *engine;
+
+	if (!arg) {
+		BREAK_TO_DEBUGGER();
+		return NULL;
+	}
+
+	engine = kzalloc(sizeof(struct i2c_sw_engine), GFP_KERNEL);
+
+	if (!engine) {
+		BREAK_TO_DEBUGGER();
+		return NULL;
+	}
+
+	dal_i2c_sw_engine_construct(engine, arg);
+	return &engine->base;
+}