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>
diff --git a/drivers/i2c/algos/i2c-algo-pcf.c b/drivers/i2c/algos/i2c-algo-pcf.c
index a8a5b6d..b8a6f3b 100644
--- a/drivers/i2c/algos/i2c-algo-pcf.c
+++ b/drivers/i2c/algos/i2c-algo-pcf.c
@@ -331,13 +331,16 @@
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 @@
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 @@
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 @@
}
}
+out:
+ if (adap->xfer_end)
+ adap->xfer_end(adap->data);
return (i);
}