drm/amdgpu/pm: rework i2c xfers on sienna cichlid (v4)

Make it generic so we can support more than just EEPROMs.

v2: fix restart handling between transactions.
v3: handle 7 to 8 bit addr conversion
v4: Fix &req --> req. (Luben T)
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Luben Tuikov <luben.tuikov@amd.com>
Reviewed-by: Luben Tuikov <luben.tuikov@amd.com>

drivers/gpu/drm/amd/pm/swsmu/smu11/sienna_cichlid_ppt.c

@@ -3442,197 +3442,84 @@ static void sienna_cichlid_dump_pptable(struct smu_context *smu)
 	dev_info(smu->adev->dev, "MmHubPadding[7] = 0x%x\n", pptable->MmHubPadding[7]);
 }
 
-static void sienna_cichlid_fill_i2c_req(SwI2cRequest_t  *req, bool write,
-				  uint8_t address, uint32_t numbytes,
-				  uint8_t *data)
-{
-	int i;
-
-	req->I2CcontrollerPort = 1;
-	req->I2CSpeed = 2;
-	req->SlaveAddress = address;
-	req->NumCmds = numbytes;
-
-	for (i = 0; i < numbytes; i++) {
-		SwI2cCmd_t *cmd =  &req->SwI2cCmds[i];
-
-		/* First 2 bytes are always write for lower 2b EEPROM address */
-		if (i < 2)
-			cmd->CmdConfig = CMDCONFIG_READWRITE_MASK;
-		else
-			cmd->CmdConfig = write ? CMDCONFIG_READWRITE_MASK : 0;
-
-
-		/* Add RESTART for read  after address filled */
-		cmd->CmdConfig |= (i == 2 && !write) ? CMDCONFIG_RESTART_MASK : 0;
-
-		/* Add STOP in the end */
-		cmd->CmdConfig |= (i == (numbytes - 1)) ? CMDCONFIG_STOP_MASK : 0;
-
-		/* Fill with data regardless if read or write to simplify code */
-		cmd->ReadWriteData = data[i];
-	}
-}
-
-static int sienna_cichlid_i2c_read_data(struct i2c_adapter *control,
-					       uint8_t address,
-					       uint8_t *data,
-					       uint32_t numbytes)
+static int sienna_cichlid_i2c_xfer(struct i2c_adapter *i2c_adap,
+				   struct i2c_msg *msgs, int num)
 {
-	uint32_t  i, ret = 0;
-	SwI2cRequest_t req;
-	struct amdgpu_device *adev = to_amdgpu_device(control);
+	struct amdgpu_device *adev = to_amdgpu_device(i2c_adap);
 	struct smu_table_context *smu_table = &adev->smu.smu_table;
 	struct smu_table *table = &smu_table->driver_table;
-
-	if (numbytes > MAX_SW_I2C_COMMANDS) {
-		dev_err(adev->dev, "numbytes requested %d is over max allowed %d\n",
-			numbytes, MAX_SW_I2C_COMMANDS);
-		return -EINVAL;
+	SwI2cRequest_t *req, *res = (SwI2cRequest_t *)table->cpu_addr;
+	u16 bytes_to_transfer, remaining_bytes, msg_bytes;
+	u16 available_bytes = MAX_SW_I2C_COMMANDS;
+	int i, j, r, c;
+	u8 slave;
+
+	/* only support a single slave addr per transaction */
+	slave = msgs[0].addr;
+	for (i = 0; i < num; i++) {
+		if (slave != msgs[i].addr)
+			return -EINVAL;
+		bytes_to_transfer += min(msgs[i].len, available_bytes);
+		available_bytes -= bytes_to_transfer;
 	}
 
-	memset(&req, 0, sizeof(req));
-	sienna_cichlid_fill_i2c_req(&req, false, address, numbytes, data);
-
-	mutex_lock(&adev->smu.mutex);
-	/* Now read data starting with that address */
-	ret = smu_cmn_update_table(&adev->smu, SMU_TABLE_I2C_COMMANDS, 0, &req,
-					true);
-	mutex_unlock(&adev->smu.mutex);
-
-	if (!ret) {
-		SwI2cRequest_t *res = (SwI2cRequest_t *)table->cpu_addr;
-
-		/* Assume SMU  fills res.SwI2cCmds[i].Data with read bytes */
-		for (i = 0; i < numbytes; i++)
-			data[i] = res->SwI2cCmds[i].ReadWriteData;
-
-		dev_dbg(adev->dev, "sienna_cichlid_i2c_read_data, address = %x, bytes = %d, data :",
-				  (uint16_t)address, numbytes);
+	req = kzalloc(sizeof(*req), GFP_KERNEL);
+	if (!req)
+		return -ENOMEM;
 
-		print_hex_dump(KERN_DEBUG, "data: ", DUMP_PREFIX_NONE,
-			       8, 1, data, numbytes, false);
-	} else
-		dev_err(adev->dev, "sienna_cichlid_i2c_read_data - error occurred :%x", ret);
+	req->I2CcontrollerPort = 1;
+	req->I2CSpeed = I2C_SPEED_FAST_400K;
+	req->SlaveAddress = slave << 1; /* 8 bit addresses */
+	req->NumCmds = bytes_to_transfer;
 
-	return ret;
-}
+	remaining_bytes = bytes_to_transfer;
+	c = 0;
+	for (i = 0; i < num; i++) {
+		struct i2c_msg *msg = &msgs[i];
 
-static int sienna_cichlid_i2c_write_data(struct i2c_adapter *control,
-						uint8_t address,
-						uint8_t *data,
-						uint32_t numbytes)
-{
-	uint32_t ret;
-	SwI2cRequest_t req;
-	struct amdgpu_device *adev = to_amdgpu_device(control);
+		msg_bytes = min(msg->len, remaining_bytes);
+		for (j = 0; j < msg_bytes; j++) {
+			SwI2cCmd_t *cmd = &req->SwI2cCmds[c++];
 
-	if (numbytes > MAX_SW_I2C_COMMANDS) {
-		dev_err(adev->dev, "numbytes requested %d is over max allowed %d\n",
-			numbytes, MAX_SW_I2C_COMMANDS);
-		return -EINVAL;
+			remaining_bytes--;
+			if (!(msg[i].flags & I2C_M_RD)) {
+				/* write */
+				cmd->CmdConfig |= CMDCONFIG_READWRITE_MASK;
+				cmd->ReadWriteData = msg->buf[j];
+			}
+			if ((msg[i].flags & I2C_M_STOP) ||
+			    (!remaining_bytes))
+				cmd->CmdConfig |= CMDCONFIG_STOP_MASK;
+			if ((i > 0) && !(msg[i].flags & I2C_M_NOSTART))
+				cmd->CmdConfig |= CMDCONFIG_RESTART_BIT;
+		}
 	}
-
-	memset(&req, 0, sizeof(req));
-	sienna_cichlid_fill_i2c_req(&req, true, address, numbytes, data);
-
 	mutex_lock(&adev->smu.mutex);
-	ret = smu_cmn_update_table(&adev->smu, SMU_TABLE_I2C_COMMANDS, 0, &req, true);
+	r = smu_cmn_update_table(&adev->smu, SMU_TABLE_I2C_COMMANDS, 0, req, true);
 	mutex_unlock(&adev->smu.mutex);
+	if (r)
+		goto fail;
 
-	if (!ret) {
-		dev_dbg(adev->dev, "sienna_cichlid_i2c_write(), address = %x, bytes = %d , data: ",
-					 (uint16_t)address, numbytes);
-
-		print_hex_dump(KERN_DEBUG, "data: ", DUMP_PREFIX_NONE,
-			       8, 1, data, numbytes, false);
-		/*
-		 * According to EEPROM spec there is a MAX of 10 ms required for
-		 * EEPROM to flush internal RX buffer after STOP was issued at the
-		 * end of write transaction. During this time the EEPROM will not be
-		 * responsive to any more commands - so wait a bit more.
-		 */
-		msleep(10);
-
-	} else
-		dev_err(adev->dev, "sienna_cichlid_i2c_write- error occurred :%x", ret);
-
-	return ret;
-}
-
-static int sienna_cichlid_i2c_xfer(struct i2c_adapter *i2c_adap,
-			      struct i2c_msg *msgs, int num)
-{
-	uint32_t  i, j, ret, data_size, data_chunk_size, next_eeprom_addr = 0;
-	uint8_t *data_ptr, data_chunk[MAX_SW_I2C_COMMANDS] = { 0 };
-
+	remaining_bytes = bytes_to_transfer;
+	c = 0;
 	for (i = 0; i < num; i++) {
-		/*
-		 * SMU interface allows at most MAX_SW_I2C_COMMANDS bytes of data at
-		 * once and hence the data needs to be spliced into chunks and sent each
-		 * chunk separately
-		 */
-		data_size = msgs[i].len - 2;
-		data_chunk_size = MAX_SW_I2C_COMMANDS - 2;
-		next_eeprom_addr = (msgs[i].buf[0] << 8 & 0xff00) | (msgs[i].buf[1] & 0xff);
-		data_ptr = msgs[i].buf + 2;
-
-		for (j = 0; j < data_size / data_chunk_size; j++) {
-			/* Insert the EEPROM dest addess, bits 0-15 */
-			data_chunk[0] = ((next_eeprom_addr >> 8) & 0xff);
-			data_chunk[1] = (next_eeprom_addr & 0xff);
-
-			if (msgs[i].flags & I2C_M_RD) {
-				ret = sienna_cichlid_i2c_read_data(i2c_adap,
-							     (uint8_t)msgs[i].addr,
-							     data_chunk, MAX_SW_I2C_COMMANDS);
-
-				memcpy(data_ptr, data_chunk + 2, data_chunk_size);
-			} else {
+		struct i2c_msg *msg = &msgs[i];
 
-				memcpy(data_chunk + 2, data_ptr, data_chunk_size);
-
-				ret = sienna_cichlid_i2c_write_data(i2c_adap,
-							      (uint8_t)msgs[i].addr,
-							      data_chunk, MAX_SW_I2C_COMMANDS);
-			}
+		msg_bytes = min(msg->len, remaining_bytes);
+		for (j = 0; j < msg_bytes; j++) {
+			SwI2cCmd_t *cmd = &res->SwI2cCmds[c++];
 
-			if (ret) {
-				num = -EIO;
-				goto fail;
-			}
-
-			next_eeprom_addr += data_chunk_size;
-			data_ptr += data_chunk_size;
-		}
-
-		if (data_size % data_chunk_size) {
-			data_chunk[0] = ((next_eeprom_addr >> 8) & 0xff);
-			data_chunk[1] = (next_eeprom_addr & 0xff);
-
-			if (msgs[i].flags & I2C_M_RD) {
-				ret = sienna_cichlid_i2c_read_data(i2c_adap,
-							     (uint8_t)msgs[i].addr,
-							     data_chunk, (data_size % data_chunk_size) + 2);
-
-				memcpy(data_ptr, data_chunk + 2, data_size % data_chunk_size);
-			} else {
-				memcpy(data_chunk + 2, data_ptr, data_size % data_chunk_size);
-
-				ret = sienna_cichlid_i2c_write_data(i2c_adap,
-							      (uint8_t)msgs[i].addr,
-							      data_chunk, (data_size % data_chunk_size) + 2);
-			}
-
-			if (ret) {
-				num = -EIO;
-				goto fail;
-			}
+			remaining_bytes--;
+			if (msg[i].flags & I2C_M_RD)
+				msg->buf[j] = cmd->ReadWriteData;
 		}
 	}
+	r = bytes_to_transfer;
 
 fail:
-	return num;
+	kfree(req);
+
+	return r;
 }
 
 static u32 sienna_cichlid_i2c_func(struct i2c_adapter *adap)