drm/amd/pm: Simplify managed I2C transfer functions

Now that we have an I2C quirk table for
SMU-managed I2C controllers, the I2C core does the
checks for us, so we don't need to do them, and so
simplify the managed I2C transfer functions.

Also, for Arcturus and Navi10, fix setting the
command type from "cmd->CmdConfig" to "cmd->Cmd".
The latter is what appears to be taking in
the enumeration I2C_CMD_... as an integer,
not a bit-flag.

For Sienna, the "Cmd" field seems to have been
eliminated, and command type and flags all live in
the "CmdConfig" field--this is left untouched.

Fix: Detect and add changing of direction
bit-flag, as this is necessary for the SMU to
detect the direction change in the 1-d array of
data it gets.

Cc: Jean Delvare <jdelvare@suse.de>
Cc: Alexander Deucher <Alexander.Deucher@amd.com>
Cc: Andrey Grodzovsky <Andrey.Grodzovsky@amd.com>
Cc: Lijo Lazar <Lijo.Lazar@amd.com>
Cc: Stanley Yang <Stanley.Yang@amd.com>
Cc: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Luben Tuikov <luben.tuikov@amd.com>
Acked-by: Alexander Deucher <Alexander.Deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 31 insertions, 45 deletions

diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu11/sienna_cichlid_ppt.c b/drivers/gpu/drm/amd/pm/swsmu/smu11/sienna_cichlid_ppt.c
index 37cfe0ccd686..0c3407025eb2 100644
--- a/drivers/gpu/drm/amd/pm/swsmu/smu11/sienna_cichlid_ppt.c
+++ b/drivers/gpu/drm/amd/pm/swsmu/smu11/sienna_cichlid_ppt.c
@@ -3443,31 +3443,14 @@ static void sienna_cichlid_dump_pptable(struct smu_context *smu)
 }
 
 static int sienna_cichlid_i2c_xfer(struct i2c_adapter *i2c_adap,
-				   struct i2c_msg *msgs, int num)
+				   struct i2c_msg *msg, int num_msgs)
 {
 	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;
-	short available_bytes = MAX_SW_I2C_COMMANDS;
-	int i, j, r, c, num_done = 0;
-	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;
-
-		available_bytes -= msgs[i].len;
-		if (available_bytes >= 0) {
-			num_done++;
-		} else {
-			/* This message and all the follwing won't be processed */
-			available_bytes += msgs[i].len;
-			break;
-		}
-	}
+	int i, j, r, c;
+	u16 dir;
 
 	req = kzalloc(sizeof(*req), GFP_KERNEL);
 	if (!req)
@@ -3475,33 +3458,38 @@ static int sienna_cichlid_i2c_xfer(struct i2c_adapter *i2c_adap,
 
 	req->I2CcontrollerPort = 1;
 	req->I2CSpeed = I2C_SPEED_FAST_400K;
-	req->SlaveAddress = slave << 1; /* 8 bit addresses */
-	req->NumCmds = MAX_SW_I2C_COMMANDS - available_bytes;;
+	req->SlaveAddress = msg[0].addr << 1; /* wants an 8-bit address */
+	dir = msg[0].flags & I2C_M_RD;
 
-	c = 0;
-	for (i = 0; i < num_done; i++) {
-		struct i2c_msg *msg = &msgs[i];
-
-		for (j = 0; j < msg->len; j++) {
-			SwI2cCmd_t *cmd = &req->SwI2cCmds[c++];
+	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->buf[j];
+				cmd->ReadWriteData = msg[i].buf[j];
+			}
+
+			if ((dir ^ msg[i].flags) & I2C_M_RD) {
+				/* The direction changes.
+				 */
+				dir = msg[i].flags & I2C_M_RD;
+				cmd->CmdConfig |= CMDCONFIG_RESTART_MASK;
 			}
 
+			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->len -1 ) &&
-			    ((i == num_done - 1) || (msg[i].flags & I2C_M_STOP)))
+			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;
-
-			if ((j == 0) && !(msg[i].flags & I2C_M_NOSTART))
-				cmd->CmdConfig |= CMDCONFIG_RESTART_BIT;
+			}
 		}
 	}
 	mutex_lock(&adev->smu.mutex);
@@ -3510,22 +3498,20 @@ static int sienna_cichlid_i2c_xfer(struct i2c_adapter *i2c_adap,
 	if (r)
 		goto fail;
 
-	c = 0;
-	for (i = 0; i < num_done; i++) {
-		struct i2c_msg *msg = &msgs[i];
-
-		for (j = 0; j < msg->len; j++) {
-			SwI2cCmd_t *cmd = &res->SwI2cCmds[c++];
+	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 (msg[i].flags & I2C_M_RD)
-				msg->buf[j] = cmd->ReadWriteData;
+			msg[i].buf[j] = cmd->ReadWriteData;
 		}
 	}
-	r = num_done;
-
+	r = num_msgs;
 fail:
 	kfree(req);
-
 	return r;
 }