From 3814ea4f0002536ac592480b2cdafa319a16e329 Mon Sep 17 00:00:00 2001 From: Mike Frysinger Date: Wed, 14 Oct 2009 19:27:26 -0400 Subject: 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 --- drivers/i2c/bfin-twi_i2c.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) (limited to 'drivers/i2c') diff --git a/drivers/i2c/bfin-twi_i2c.c b/drivers/i2c/bfin-twi_i2c.c index e79063407..5ef30beca 100644 --- a/drivers/i2c/bfin-twi_i2c.c +++ b/drivers/i2c/bfin-twi_i2c.c @@ -60,6 +60,9 @@ struct i2c_msg { 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 @@ struct i2c_msg { 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 @@ static int wait_for_completion(struct i2c_msg *msg) 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 @@ static int wait_for_completion(struct i2c_msg *msg) } 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; } -- cgit v1.2.3