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Commit 02864d58 authored by Jean Delvare's avatar Jean Delvare
Browse files

i2c-powermac: Refactor i2c_powermac_smbus_xfer 



I wanted to add some error logging to the i2c-powermac driver, but
found that it was very difficult due to the way the
i2c_powermac_smbus_xfer function is organized. Refactor the code in
this function so that each low-level function is only called once.

Signed-off-by: default avatarJean Delvare <khali@linux-fr.org>
Tested-by: default avatarMichel Daenzer <michel@daenzer.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
parent 6f7e549f

drivers/i2c/busses/i2c-powermac.c

+41 −44
Original line number Diff line number Diff line
@@ -49,48 +49,38 @@ static s32 i2c_powermac_smbus_xfer( struct i2c_adapter* adap, 
	int			rc = 0;

	int			read = (read_write == I2C_SMBUS_READ);

	int			addrdir = (addr << 1) | read;

	int			mode, subsize, len;

	u32			subaddr;

	u8			*buf;

	u8			local[2];



	rc = pmac_i2c_open(bus, 0);

	if (rc)

		return rc;

	if (size == I2C_SMBUS_QUICK || size == I2C_SMBUS_BYTE) {

		mode = pmac_i2c_mode_std;

		subsize = 0;

		subaddr = 0;

	} else {

		mode = read ? pmac_i2c_mode_combined : pmac_i2c_mode_stdsub;

		subsize = 1;

		subaddr = command;

	}



	switch (size) {

        case I2C_SMBUS_QUICK:

		rc = pmac_i2c_setmode(bus, pmac_i2c_mode_std);

		if (rc)

			goto bail;

		rc = pmac_i2c_xfer(bus, addrdir, 0, 0, NULL, 0);

		buf = NULL;

		len = 0;

	    	break;

        case I2C_SMBUS_BYTE:

		rc = pmac_i2c_setmode(bus, pmac_i2c_mode_std);

		if (rc)

			goto bail;

		rc = pmac_i2c_xfer(bus, addrdir, 0, 0, &data->byte, 1);

	    	break;

        case I2C_SMBUS_BYTE_DATA:

		rc = pmac_i2c_setmode(bus, read ?

				      pmac_i2c_mode_combined :

				      pmac_i2c_mode_stdsub);

		if (rc)

			goto bail;

		rc = pmac_i2c_xfer(bus, addrdir, 1, command, &data->byte, 1);

		buf = &data->byte;

		len = 1;

	    	break;

        case I2C_SMBUS_WORD_DATA:

		rc = pmac_i2c_setmode(bus, read ?

				      pmac_i2c_mode_combined :

				      pmac_i2c_mode_stdsub);

		if (rc)

			goto bail;

		if (!read) {

			local[0] = data->word & 0xff;

			local[1] = (data->word >> 8) & 0xff;

		}

		rc = pmac_i2c_xfer(bus, addrdir, 1, command, local, 2);

		if (rc == 0 && read) {

			data->word = ((u16)local[1]) << 8;

			data->word |= local[0];

		}

		buf = local;

		len = 2;

	    	break;



	/* Note that these are broken vs. the expected smbus API where
@@ -105,28 +95,35 @@ static s32 i2c_powermac_smbus_xfer( struct i2c_adapter* adap, 
	 * a repeat start/addr phase (but not stop in between)

	 */

        case I2C_SMBUS_BLOCK_DATA:

		rc = pmac_i2c_setmode(bus, read ?

				      pmac_i2c_mode_combined :

				      pmac_i2c_mode_stdsub);

		buf = data->block;

		len = data->block[0] + 1;

		break;

	case I2C_SMBUS_I2C_BLOCK_DATA:

		buf = &data->block[1];

		len = data->block[0];

		break;



        default:

		return -EINVAL;

	}



	rc = pmac_i2c_open(bus, 0);

	if (rc)

		return rc;



	rc = pmac_i2c_setmode(bus, mode);

	if (rc)

		goto bail;

		rc = pmac_i2c_xfer(bus, addrdir, 1, command, data->block,

				   data->block[0] + 1);



		break;

	case I2C_SMBUS_I2C_BLOCK_DATA:

		rc = pmac_i2c_setmode(bus, read ?

				      pmac_i2c_mode_combined :

				      pmac_i2c_mode_stdsub);

	rc = pmac_i2c_xfer(bus, addrdir, subsize, subaddr, buf, len);

	if (rc)

		goto bail;

		rc = pmac_i2c_xfer(bus, addrdir, 1, command,

				   &data->block[1], data->block[0]);

		break;



        default:

	    	rc = -EINVAL;

	if (size == I2C_SMBUS_WORD_DATA && read) {

		data->word = ((u16)local[1]) << 8;

		data->word |= local[0];

	}



 bail:

	pmac_i2c_close(bus);

	return rc;