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| author | Jan Luebbe <jluebbe@debian.org> | 2015-07-30 16:52:10 +0200 |
|---|---|---|
| committer | Sascha Hauer <s.hauer@pengutronix.de> | 2015-08-20 07:47:15 +0200 |
| commit | 4f32ba9fcbbdcbfdb6dec75fe70ba8998a82e3ca (patch) | |
| tree | 937f12684e7516a1614cf588e94fa61c85435c87 /drivers/i2c | |
| parent | abcbcfca3abbebb2cab28fdada7daf135cc6b33d (diff) | |
| download | barebox-4f32ba9fcbbdcbfdb6dec75fe70ba8998a82e3ca.tar.gz barebox-4f32ba9fcbbdcbfdb6dec75fe70ba8998a82e3ca.tar.xz | |
i2c: algo-bit: check if the bus is busy
If we have a timeout while waiting, try to recover.
Signed-off-by: Jan Luebbe <jluebbe@debian.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Diffstat (limited to 'drivers/i2c')
| -rw-r--r-- | drivers/i2c/algos/i2c-algo-bit.c | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/drivers/i2c/algos/i2c-algo-bit.c b/drivers/i2c/algos/i2c-algo-bit.c index 62040cc4e4..2563c0d25a 100644 --- a/drivers/i2c/algos/i2c-algo-bit.c +++ b/drivers/i2c/algos/i2c-algo-bit.c @@ -117,6 +117,31 @@ done: return 0; } +static int wait_busy(struct i2c_algo_bit_data *adap) +{ + uint64_t start; + + if (sclhi(adap) < 0) + return -ETIMEDOUT; + + start = get_time_ns(); + while (!getsda(adap)) { + if (is_timeout(start, adap->timeout_ms * MSECOND)) { + if (getsda(adap)) + break; + return -ETIMEDOUT; + } + } +#ifdef DEBUG + if ((get_time_ns() - start) < 10000) + pr_debug("i2c-algo-bit: needed %u usecs for SDA to go " + "high\n", (unsigned int)(get_time_ns() - start) / + 1000); +#endif + + udelay(adap->udelay); + return 0; +} /* --- other auxiliary functions -------------------------------------- */ static void i2c_start(struct i2c_algo_bit_data *adap) @@ -512,6 +537,13 @@ static int bit_xfer(struct i2c_adapter *i2c_adap, return ret; } + if (wait_busy(adap) < 0) { /* timeout */ + dev_warn(&i2c_adap->dev, "timeout waiting for bus ready\n"); + ret = i2c_recover_bus(i2c_adap); + if (ret < 0) + return ret; + } + bit_dbg(3, &i2c_adap->dev, "emitting start condition\n"); i2c_start(adap); for (i = 0; i < num; i++) { |