On Sat, 2009-10-10 at 14:19 +0200, Jean Delvare wrote:
> 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: Jean Delvare <[email protected]>
> Cc: Benjamin Herrenschmidt <[email protected]>
> Cc: Paul Mackerras <[email protected]>
> ---
> This needs testing! Thanks.
Ok, will give it a go next week.
Cheers,
Ben.
> drivers/i2c/busses/i2c-powermac.c | 85
> +++++++++++++++++--------------------
> 1 file changed, 41 insertions(+), 44 deletions(-)
>
> --- linux-2.6.32-rc3.orig/drivers/i2c/busses/i2c-powermac.c 2009-10-10
> 14:08:39.000000000 +0200
> +++ linux-2.6.32-rc3/drivers/i2c/busses/i2c-powermac.c 2009-10-10
> 14:13:04.000000000 +0200
> @@ -49,48 +49,38 @@ static s32 i2c_powermac_smbus_xfer( stru
> 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( stru
> * 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);
> - if (rc)
> - goto bail;
> - rc = pmac_i2c_xfer(bus, addrdir, 1, command, data->block,
> - data->block[0] + 1);
> -
> + buf = data->block;
> + len = 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);
> - if (rc)
> - goto bail;
> - rc = pmac_i2c_xfer(bus, addrdir, 1, command,
> - &data->block[1], data->block[0]);
> + buf = &data->block[1];
> + len = data->block[0];
> break;
>
> default:
> - rc = -EINVAL;
> + 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, subsize, subaddr, buf, len);
> + if (rc)
> + goto bail;
> +
> + if (size == I2C_SMBUS_WORD_DATA && read) {
> + data->word = ((u16)local[1]) << 8;
> + data->word |= local[0];
> }
> +
> bail:
> pmac_i2c_close(bus);
> return rc;
>
>
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