[PATCH 6/8] i2c: i801: add i801_single_transaction(), complementing i801_block_transaction()

[Heiner Kallweit <hkallweit1@gmail.com>]

This patch factors out non-block pre/post processing to a new function
i801_single_transaction(), complementing existing function
i801_block_transaction(). This makes i801_access() better readable.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
---
 drivers/i2c/busses/i2c-i801.c | 95 +++++++++++++++++++++--------------
 1 file changed, 58 insertions(+), 37 deletions(-)

diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c
index bf77f8640..8c2245f38 100644
--- a/drivers/i2c/busses/i2c-i801.c
+++ b/drivers/i2c/busses/i2c-i801.c
@@ -771,6 +771,62 @@ static int i801_block_transaction(struct i801_priv *priv, union i2c_smbus_data *
 	return result;
 }
 
+/* Single transaction function */
+static int i801_single_transaction(struct i801_priv *priv, union i2c_smbus_data *data,
+				   char read_write, int command)
+{
+	int xact, ret;
+
+	switch (command) {
+	case I2C_SMBUS_QUICK:
+		xact = I801_QUICK;
+		break;
+	case I2C_SMBUS_BYTE:
+                xact = I801_BYTE;
+                break;
+	case I2C_SMBUS_BYTE_DATA:
+		if (read_write == I2C_SMBUS_WRITE)
+			outb_p(data->byte, SMBHSTDAT0(priv));
+		xact = I801_BYTE_DATA;
+		break;
+	case I2C_SMBUS_WORD_DATA:
+		if (read_write == I2C_SMBUS_WRITE) {
+			outb_p(data->word & 0xff, SMBHSTDAT0(priv));
+			outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1(priv));
+		}
+		xact = I801_WORD_DATA;
+		break;
+	case I2C_SMBUS_PROC_CALL:
+		outb_p(data->word & 0xff, SMBHSTDAT0(priv));
+		outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1(priv));
+		xact = I801_PROC_CALL;
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	ret = i801_transaction(priv, xact);
+
+	if (ret || read_write == I2C_SMBUS_WRITE)
+		return ret;
+
+	switch (command) {
+	case I2C_SMBUS_BYTE:
+	case I2C_SMBUS_BYTE_DATA:
+		data->byte = inb_p(SMBHSTDAT0(priv));
+		break;
+	case I2C_SMBUS_WORD_DATA:
+	case I2C_SMBUS_PROC_CALL:
+		data->word = inb_p(SMBHSTDAT0(priv)) +
+			     (inb_p(SMBHSTDAT1(priv)) << 8);
+		break;
+	default:
+		break;
+	}
+
+	return 0;
+}
+
 static void i801_set_hstadd(struct i801_priv *priv, u8 addr, char read_write)
 {
 	addr <<= 1;
@@ -784,9 +840,7 @@ static s32 i801_access(struct i2c_adapter *adap, u16 addr,
 		       unsigned short flags, char read_write, u8 command,
 		       int size, union i2c_smbus_data *data)
 {
-	int hwpec;
-	int block = 0;
-	int ret, xact;
+	int hwpec, ret, block = 0;
 	struct i801_priv *priv = i2c_get_adapdata(adap);
 
 	mutex_lock(&priv->acpi_lock);
@@ -804,36 +858,23 @@ static s32 i801_access(struct i2c_adapter *adap, u16 addr,
 	switch (size) {
 	case I2C_SMBUS_QUICK:
 		i801_set_hstadd(priv, addr, read_write);
-		xact = I801_QUICK;
 		break;
 	case I2C_SMBUS_BYTE:
 		i801_set_hstadd(priv, addr, read_write);
 		if (read_write == I2C_SMBUS_WRITE)
 			outb_p(command, SMBHSTCMD(priv));
-		xact = I801_BYTE;
 		break;
 	case I2C_SMBUS_BYTE_DATA:
 		i801_set_hstadd(priv, addr, read_write);
 		outb_p(command, SMBHSTCMD(priv));
-		if (read_write == I2C_SMBUS_WRITE)
-			outb_p(data->byte, SMBHSTDAT0(priv));
-		xact = I801_BYTE_DATA;
 		break;
 	case I2C_SMBUS_WORD_DATA:
 		i801_set_hstadd(priv, addr, read_write);
 		outb_p(command, SMBHSTCMD(priv));
-		if (read_write == I2C_SMBUS_WRITE) {
-			outb_p(data->word & 0xff, SMBHSTDAT0(priv));
-			outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1(priv));
-		}
-		xact = I801_WORD_DATA;
 		break;
 	case I2C_SMBUS_PROC_CALL:
 		i801_set_hstadd(priv, addr, I2C_SMBUS_WRITE);
 		outb_p(command, SMBHSTCMD(priv));
-		outb_p(data->word & 0xff, SMBHSTDAT0(priv));
-		outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1(priv));
-		xact = I801_PROC_CALL;
 		read_write = I2C_SMBUS_READ;
 		break;
 	case I2C_SMBUS_BLOCK_DATA:
@@ -883,7 +924,7 @@ static s32 i801_access(struct i2c_adapter *adap, u16 addr,
 	if (block)
 		ret = i801_block_transaction(priv, data, read_write, size);
 	else
-		ret = i801_transaction(priv, xact);
+		ret = i801_single_transaction(priv, data, read_write, size);
 
 	/* Some BIOSes don't like it when PEC is enabled at reboot or resume
 	   time, so we forcibly disable it after every transaction. Turn off
@@ -891,26 +932,6 @@ static s32 i801_access(struct i2c_adapter *adap, u16 addr,
 	if (hwpec || block)
 		outb_p(inb_p(SMBAUXCTL(priv)) &
 		       ~(SMBAUXCTL_CRC | SMBAUXCTL_E32B), SMBAUXCTL(priv));
-
-	if (block)
-		goto out;
-	if (ret)
-		goto out;
-	if ((read_write == I2C_SMBUS_WRITE) || (xact == I801_QUICK))
-		goto out;
-
-	switch (xact) {
-	case I801_BYTE:	/* Result put in SMBHSTDAT0 */
-	case I801_BYTE_DATA:
-		data->byte = inb_p(SMBHSTDAT0(priv));
-		break;
-	case I801_WORD_DATA:
-	case I801_PROC_CALL:
-		data->word = inb_p(SMBHSTDAT0(priv)) +
-			     (inb_p(SMBHSTDAT1(priv)) << 8);
-		break;
-	}
-
 out:
 	/*
 	 * Unlock the SMBus device for use by BIOS/ACPI,
-- 
2.35.3