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| author | Wolfram Sang <wsa+renesas@sang-engineering.com> | 2017-12-04 09:16:18 +0100 |
|---|---|---|
| committer | Wolfram Sang <wsa@the-dreams.de> | 2017-12-31 00:16:37 +0100 |
| commit | 3e5f06bed72fe72166a6778f630241a893f67799 (patch) | |
| tree | ecfdc707cf42d7e687ba406bc8042ba502c65bb4 | |
| parent | e53537653791b4aaa9ec88a9eb5fd187d44ff6ac (diff) | |
| download | linux-3e5f06bed72fe72166a6778f630241a893f67799.tar.bz2 | |
i2c: algo-bit: init the bus to a known state
Ensure the bus is free when we register the adapter. Before the SCL/SDA
wires were in an unknown state. It used to work because sending a byte
has a retry mechanism which was triggered if the bus was initially in a
non-free state. But the graceful way to do it is to initialize
correctly.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| -rw-r--r-- | drivers/i2c/algos/i2c-algo-bit.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/i2c/algos/i2c-algo-bit.c b/drivers/i2c/algos/i2c-algo-bit.c index 1147bddb8b2c..3df0efd69ae3 100644 --- a/drivers/i2c/algos/i2c-algo-bit.c +++ b/drivers/i2c/algos/i2c-algo-bit.c @@ -649,6 +649,11 @@ static int __i2c_bit_add_bus(struct i2c_adapter *adap, if (bit_adap->getscl == NULL) adap->quirks = &i2c_bit_quirk_no_clk_stretch; + /* Bring bus to a known state. Looks like STOP if bus is not free yet */ + setscl(bit_adap, 1); + udelay(bit_adap->udelay); + setsda(bit_adap, 1); + ret = add_adapter(adap); if (ret < 0) return ret; |