Commit 6ff9d46c authored by Heiner Kallweit's avatar Heiner Kallweit Committed by Andi Shyti
Browse files

i2c: i801: Split i801_block_transaction 



i2c and smbus block transaction handling have little in common,
therefore split this function to improve code readability.

Signed-off-by: default avatarHeiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: default avatarAndi Shyti <andi.shyti@kernel.org>
Signed-off-by: default avatarAndi Shyti <andi.shyti@kernel.org>
parent 03f9863b

drivers/i2c/busses/i2c-i801.c

+50 −62
Original line number Diff line number Diff line
@@ -802,77 +802,65 @@ static int i801_simple_transaction(struct i801_priv *priv, union i2c_smbus_data 
	return 0;

}



/* Block transaction function */

static int i801_block_transaction(struct i801_priv *priv, union i2c_smbus_data *data,

static int i801_smbus_block_transaction(struct i801_priv *priv, union i2c_smbus_data *data,

					u8 addr, u8 hstcmd, char read_write, int command)

{

	int result = 0;

	unsigned char hostc;



	if (read_write == I2C_SMBUS_READ && command == I2C_SMBUS_BLOCK_DATA)

		data->block[0] = I2C_SMBUS_BLOCK_MAX;

	else if (data->block[0] < 1 || data->block[0] > I2C_SMBUS_BLOCK_MAX)

		return -EPROTO;



	switch (command) {

	case I2C_SMBUS_BLOCK_DATA:

	if (command == I2C_SMBUS_BLOCK_PROC_CALL)

		/* Needs to be flagged as write transaction */

		i801_set_hstadd(priv, addr, I2C_SMBUS_WRITE);

	else

		i801_set_hstadd(priv, addr, read_write);

	outb_p(hstcmd, SMBHSTCMD(priv));

		break;

	case I2C_SMBUS_I2C_BLOCK_DATA:



	if (priv->features & FEATURE_BLOCK_BUFFER)

		return i801_block_transaction_by_block(priv, data, read_write, command);

	else

		return i801_block_transaction_byte_by_byte(priv, data, read_write, command);

}



static int i801_i2c_block_transaction(struct i801_priv *priv, union i2c_smbus_data *data,

				      u8 addr, u8 hstcmd, char read_write, int command)

{

	int result;

	u8 hostc;



	if (data->block[0] < 1 || data->block[0] > I2C_SMBUS_BLOCK_MAX)

		return -EPROTO;

	/*

		 * NB: page 240 of ICH5 datasheet shows that the R/#W

		 * bit should be cleared here, even when reading.

		 * However if SPD Write Disable is set (Lynx Point and later),

	 * NB: page 240 of ICH5 datasheet shows that the R/#W bit should be cleared here,

	 * even when reading. However if SPD Write Disable is set (Lynx Point and later),

	 * the read will fail if we don't set the R/#W bit.

	 */

	i801_set_hstadd(priv, addr,

				priv->original_hstcfg & SMBHSTCFG_SPD_WD ?

				read_write : I2C_SMBUS_WRITE);

		if (read_write == I2C_SMBUS_READ) {

			/* NB: page 240 of ICH5 datasheet also shows

			 * that DATA1 is the cmd field when reading

			 */

			priv->original_hstcfg & SMBHSTCFG_SPD_WD ? read_write : I2C_SMBUS_WRITE);



	/* NB: page 240 of ICH5 datasheet shows that DATA1 is the cmd field when reading */

	if (read_write == I2C_SMBUS_READ)

		outb_p(hstcmd, SMBHSTDAT1(priv));

		} else

	else

		outb_p(hstcmd, SMBHSTCMD(priv));



	if (read_write == I2C_SMBUS_WRITE) {

		/* set I2C_EN bit in configuration register */

		pci_read_config_byte(priv->pci_dev, SMBHSTCFG, &hostc);

			pci_write_config_byte(priv->pci_dev, SMBHSTCFG,

					      hostc | SMBHSTCFG_I2C_EN);

		pci_write_config_byte(priv->pci_dev, SMBHSTCFG, hostc | SMBHSTCFG_I2C_EN);

	} else if (!(priv->features & FEATURE_I2C_BLOCK_READ)) {

			dev_err(&priv->pci_dev->dev,

				"I2C block read is unsupported!\n");

		pci_err(priv->pci_dev, "I2C block read is unsupported!\n");

		return -EOPNOTSUPP;

	}

		break;

	case I2C_SMBUS_BLOCK_PROC_CALL:

		/* Needs to be flagged as write transaction */

		i801_set_hstadd(priv, addr, I2C_SMBUS_WRITE);

		outb_p(hstcmd, SMBHSTCMD(priv));

		break;

	}



	/* Experience has shown that the block buffer can only be used for

	   SMBus (not I2C) block transactions, even though the datasheet

	   doesn't mention this limitation. */

	if ((priv->features & FEATURE_BLOCK_BUFFER) &&

	    command != I2C_SMBUS_I2C_BLOCK_DATA)

		result = i801_block_transaction_by_block(priv, data,

							 read_write,

							 command);

	else

		result = i801_block_transaction_byte_by_byte(priv, data,

							     read_write,

							     command);

	/* Block buffer isn't supported for I2C block transactions */

	result = i801_block_transaction_byte_by_byte(priv, data, read_write, command);



	if (command == I2C_SMBUS_I2C_BLOCK_DATA

	 && read_write == I2C_SMBUS_WRITE) {

	/* restore saved configuration register value */

	if (read_write == I2C_SMBUS_WRITE)

		pci_write_config_byte(priv->pci_dev, SMBHSTCFG, hostc);

	}



	return result;

}
@@ -903,10 +891,10 @@ static s32 i801_access(struct i2c_adapter *adap, u16 addr, 
		outb_p(inb_p(SMBAUXCTL(priv)) & (~SMBAUXCTL_CRC),

		       SMBAUXCTL(priv));



	if (size == I2C_SMBUS_BLOCK_DATA ||

	    size == I2C_SMBUS_I2C_BLOCK_DATA ||

	    size == I2C_SMBUS_BLOCK_PROC_CALL)

		ret = i801_block_transaction(priv, data, addr, command, read_write, size);

	if (size == I2C_SMBUS_BLOCK_DATA || size == I2C_SMBUS_BLOCK_PROC_CALL)

		ret = i801_smbus_block_transaction(priv, data, addr, command, read_write, size);

	else if (size == I2C_SMBUS_I2C_BLOCK_DATA)

		ret = i801_i2c_block_transaction(priv, data, addr, command, read_write, size);

	else

		ret = i801_simple_transaction(priv, data, addr, command, read_write, size);