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authorDavid Miller <davem@davemloft.net>2008-10-22 20:21:30 +0200
committerJean Delvare <khali@linux-fr.org>2008-10-22 20:21:30 +0200
commit30091404af5a7cd515e7b565df76932e295d8f6f (patch)
tree6ce6ecb5707aca55aff260ff3a1ce8a3453be3de /drivers/i2c
parent08e5338d119daeb3c7746fa80fa916b8d3d48e89 (diff)
i2c-algo-pcf: Add adapter hooks around xfer begin and end
Some I2C bus implementations need to synchronize with external entities, such as system firmware, which might also be programming the same I2C bus. In order to facilitate this add ->xfer_begin() and ->xfer_end() hooks which are invoked around pcf_xfer(). [JD: Make these hooks optional.] Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Jean Delvare <khali@linux-fr.org>
Diffstat (limited to 'drivers/i2c')
-rw-r--r--drivers/i2c/algos/i2c-algo-pcf.c17
1 files changed, 13 insertions, 4 deletions
diff --git a/drivers/i2c/algos/i2c-algo-pcf.c b/drivers/i2c/algos/i2c-algo-pcf.c
index a8a5b6d1dd88..b8a6f3bcbae3 100644
--- a/drivers/i2c/algos/i2c-algo-pcf.c
+++ b/drivers/i2c/algos/i2c-algo-pcf.c
@@ -331,13 +331,16 @@ static int pcf_xfer(struct i2c_adapter *i2c_adap,
int i;
int ret=0, timeout, status;
+ if (adap->xfer_begin)
+ adap->xfer_begin(adap->data);
/* Check for bus busy */
timeout = wait_for_bb(adap);
if (timeout) {
DEB2(printk(KERN_ERR "i2c-algo-pcf.o: "
"Timeout waiting for BB in pcf_xfer\n");)
- return -EIO;
+ i = -EIO;
+ goto out;
}
for (i = 0;ret >= 0 && i < num; i++) {
@@ -359,12 +362,14 @@ static int pcf_xfer(struct i2c_adapter *i2c_adap,
if (timeout) {
if (timeout == -EINTR) {
/* arbitration lost */
- return (-EINTR);
+ i = -EINTR;
+ goto out;
}
i2c_stop(adap);
DEB2(printk(KERN_ERR "i2c-algo-pcf.o: Timeout waiting "
"for PIN(1) in pcf_xfer\n");)
- return (-EREMOTEIO);
+ i = -EREMOTEIO;
+ goto out;
}
#ifndef STUB_I2C
@@ -372,7 +377,8 @@ static int pcf_xfer(struct i2c_adapter *i2c_adap,
if (status & I2C_PCF_LRB) {
i2c_stop(adap);
DEB2(printk(KERN_ERR "i2c-algo-pcf.o: No LRB(1) in pcf_xfer\n");)
- return (-EREMOTEIO);
+ i = -EREMOTEIO;
+ goto out;
}
#endif
@@ -404,6 +410,9 @@ static int pcf_xfer(struct i2c_adapter *i2c_adap,
}
}
+out:
+ if (adap->xfer_end)
+ adap->xfer_end(adap->data);
return (i);
}