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i2c: i801: Add i801_simple_transaction(), complementing i801_block_tr…
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…ansaction()

Factor out non-block pre/post processing to a new function
i801_simple_transaction(), complementing existing function
i801_block_transaction(). This makes i801_access() better readable.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
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Heiner Kallweit authored and Wolfram Sang committed Feb 17, 2023
1 parent 38bd413 commit dd2d18b
Showing 1 changed file with 55 additions and 37 deletions.
92 changes: 55 additions & 37 deletions drivers/i2c/busses/i2c-i801.c
Original file line number Diff line number Diff line change
Expand Up @@ -732,6 +732,59 @@ static void i801_set_hstadd(struct i801_priv *priv, u8 addr, char read_write)
outb_p((addr << 1) | (read_write & 0x01), SMBHSTADD(priv));
}

/* Single value transaction function */
static int i801_simple_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;
}

return 0;
}

/* Block transaction function */
static int i801_block_transaction(struct i801_priv *priv, union i2c_smbus_data *data,
char read_write, int command)
Expand Down Expand Up @@ -783,9 +836,7 @@ 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);
Expand All @@ -803,36 +854,23 @@ 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:
Expand Down Expand Up @@ -880,34 +918,14 @@ 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_simple_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
E32B for the same reason. */
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,
Expand Down

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