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 <khali@xxxxxxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
---
This needs testing! Thanks.
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;
--
Jean Delvare
--
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