[PATCH 1/3] drm/amd/pm: Simplify managed I2C transfer of Aldebaran

Luben Tuikov luben.tuikov at amd.com
Mon Jun 28 18:48:34 UTC 2021


Simplify Aldebaran managed I2C transfer function
to correctly play with the upper I2C layers.

This gets it in line with Navi10, Acturus, and
Sienna Cichlid.

Cc: Alexander Deucher <Alexander.Deucher at amd.com>
Cc: Andrey Grodzovsky <Andrey.Grodzovsky at amd.com>
Cc: Lijo Lazar <Lijo.Lazar at amd.com>
Cc: John Clements <john.clements at amd.com>
Cc: Hawking Zhang <Hawking.Zhang at amd.com>
Signed-off-by: Luben Tuikov <luben.tuikov at amd.com>
Reviewed-by: Alexander Deucher <Alexander.Deucher at amd.com>
---
 .../drm/amd/pm/swsmu/smu13/aldebaran_ppt.c    | 230 +++++-------------
 1 file changed, 55 insertions(+), 175 deletions(-)

diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu13/aldebaran_ppt.c b/drivers/gpu/drm/amd/pm/swsmu/smu13/aldebaran_ppt.c
index 9316a726195cc0..f30edf862b86d1 100644
--- a/drivers/gpu/drm/amd/pm/swsmu/smu13/aldebaran_ppt.c
+++ b/drivers/gpu/drm/amd/pm/swsmu/smu13/aldebaran_ppt.c
@@ -1425,197 +1425,77 @@ static bool aldebaran_is_dpm_running(struct smu_context *smu)
 	return !!(feature_enabled & SMC_DPM_FEATURE);
 }
 
-static void aldebaran_fill_i2c_req(SwI2cRequest_t  *req, bool write,
-				  uint8_t address, uint32_t numbytes,
-				  uint8_t *data)
-{
-	int i;
-
-	req->I2CcontrollerPort = 0;
-	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 aldebaran_i2c_read_data(struct i2c_adapter *control,
-					       uint8_t address,
-					       uint8_t *data,
-					       uint32_t numbytes)
+static int aldebaran_i2c_xfer(struct i2c_adapter *i2c_adap,
+			      struct i2c_msg *msg, int num_msgs)
 {
-	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;
+	SwI2cRequest_t *req, *res = (SwI2cRequest_t *)table->cpu_addr;
+	int i, j, r, c;
+	u16 dir;
 
-	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;
-	}
-
-	memset(&req, 0, sizeof(req));
-	aldebaran_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, "aldebaran_i2c_read_data, address = %x, bytes = %d, data :",
-				  (uint16_t)address, numbytes);
-
-		print_hex_dump(KERN_DEBUG, "data: ", DUMP_PREFIX_NONE,
-			       8, 1, data, numbytes, false);
-	} else
-		dev_err(adev->dev, "aldebaran_i2c_read_data - error occurred :%x", ret);
+	req = kzalloc(sizeof(*req), GFP_KERNEL);
+	if (!req)
+		return -ENOMEM;
 
-	return ret;
-}
+	req->I2CcontrollerPort = 0;
+	req->I2CSpeed = I2C_SPEED_FAST_400K;
+	req->SlaveAddress = msg[0].addr << 1; /* wants an 8-bit address */
+	dir = msg[0].flags & I2C_M_RD;
+
+	for (c = i = 0; i < num_msgs; i++) {
+		for (j = 0; j < msg[i].len; j++, c++) {
+			SwI2cCmd_t *cmd = &req->SwI2cCmds[c];
+
+			if (!(msg[i].flags & I2C_M_RD)) {
+				/* write */
+				cmd->CmdConfig |= CMDCONFIG_READWRITE_MASK;
+				cmd->ReadWriteData = msg[i].buf[j];
+			}
 
-static int aldebaran_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);
+			if ((dir ^ msg[i].flags) & I2C_M_RD) {
+				/* The direction changes.
+				 */
+				dir = msg[i].flags & I2C_M_RD;
+				cmd->CmdConfig |= CMDCONFIG_RESTART_MASK;
+			}
 
-	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;
+			req->NumCmds++;
+
+			/*
+			 * Insert STOP if we are at the last byte of either last
+			 * message for the transaction or the client explicitly
+			 * requires a STOP at this particular message.
+			 */
+			if ((j == msg[i].len - 1) &&
+			    ((i == num_msgs - 1) || (msg[i].flags & I2C_M_STOP))) {
+				cmd->CmdConfig &= ~CMDCONFIG_RESTART_MASK;
+				cmd->CmdConfig |= CMDCONFIG_STOP_MASK;
+			}
+		}
 	}
-
-	memset(&req, 0, sizeof(req));
-	aldebaran_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, "aldebaran_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, "aldebaran_i2c_write- error occurred :%x", ret);
-
-	return ret;
-}
-
-static int aldebaran_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 };
-
-	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 = aldebaran_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 {
-
-				memcpy(data_chunk + 2, data_ptr, data_chunk_size);
-
-				ret = aldebaran_i2c_write_data(i2c_adap,
-							      (uint8_t)msgs[i].addr,
-							      data_chunk, MAX_SW_I2C_COMMANDS);
-			}
-
-			if (ret) {
-				num = -EIO;
-				goto fail;
-			}
-
-			next_eeprom_addr += data_chunk_size;
-			data_ptr += data_chunk_size;
+	for (c = i = 0; i < num_msgs; i++) {
+		if (!(msg[i].flags & I2C_M_RD)) {
+			c += msg[i].len;
+			continue;
 		}
+		for (j = 0; j < msg[i].len; j++, c++) {
+			SwI2cCmd_t *cmd = &res->SwI2cCmds[c];
 
-		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 = aldebaran_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 = aldebaran_i2c_write_data(i2c_adap,
-							      (uint8_t)msgs[i].addr,
-							      data_chunk, (data_size % data_chunk_size) + 2);
-			}
-
-			if (ret) {
-				num = -EIO;
-				goto fail;
-			}
+			msg[i].buf[j] = cmd->ReadWriteData;
 		}
 	}
-
+	r = num_msgs;
 fail:
-	return num;
+	kfree(req);
+	return r;
 }
 
 static u32 aldebaran_i2c_func(struct i2c_adapter *adap)
-- 
2.32.0



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