Blackfin: TWI/I2C: add timeout to transfer
The current transfer code relies on ctrlc() to abort transfers, but this
requires user interactivity. Naturalize the process with a timeout.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/drivers/i2c/bfin-twi_i2c.c b/drivers/i2c/bfin-twi_i2c.c
index e790634..5ef30be 100644
--- a/drivers/i2c/bfin-twi_i2c.c
+++ b/drivers/i2c/bfin-twi_i2c.c
@@ -60,6 +60,9 @@
u8 *abuf; /* addr buffer */
};
+/* Allow msec timeout per ~byte transfer */
+#define I2C_TIMEOUT 10
+
/**
* wait_for_completion - manage the actual i2c transfer
* @msg: the i2c msg
@@ -67,8 +70,9 @@
static int wait_for_completion(struct i2c_msg *msg)
{
uint16_t int_stat;
+ ulong timebase = get_timer(0);
- while (!ctrlc()) {
+ do {
int_stat = bfin_read_TWI_INT_STAT();
if (int_stat & XMTSERV) {
@@ -103,7 +107,7 @@
debugi("processing MERR");
bfin_write_TWI_INT_STAT(MERR);
SSYNC();
- break;
+ return msg->len;
}
if (int_stat & MCOMP) {
debugi("processing MCOMP");
@@ -116,7 +120,12 @@
} else
break;
}
- }
+
+ /* If we were able to do something, reset timeout */
+ if (int_stat)
+ timebase = get_timer(0);
+
+ } while (get_timer(timebase) < I2C_TIMEOUT);
return msg->len;
}