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| author | Wolfram Sang <wsa+renesas@sang-engineering.com> | 2018-07-17 11:00:05 +0200 |
|---|---|---|
| committer | Wolfram Sang <wsa@the-dreams.de> | 2018-07-21 00:11:05 +0200 |
| commit | c4ae05b976b2a67fb24f35d21731b4da2c235bbf (patch) | |
| tree | 170f536bea2d9a57a9ea80b4409580259d67e543 /drivers/i2c | |
| parent | ea3cfbd896fd25b2a9ddfcd685858461335f7435 (diff) | |
| download | linux-c4ae05b976b2a67fb24f35d21731b4da2c235bbf.tar.gz linux-c4ae05b976b2a67fb24f35d21731b4da2c235bbf.tar.bz2 linux-c4ae05b976b2a67fb24f35d21731b4da2c235bbf.zip | |
i2c: recovery: make pin init look like STOP
When we initialize the pins, make sure it looks like STOP by dividing
the delay into halves. It shouldn't matter because SDA is expected to be
held low by a device, but for super-safety, let's do it.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com>
Reviewed-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'drivers/i2c')
| -rw-r--r-- | drivers/i2c/i2c-core-base.c | 19 |
1 files changed, 10 insertions, 9 deletions
diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c index 57538d72f2e5..02d6f27b19e4 100644 --- a/drivers/i2c/i2c-core-base.c +++ b/drivers/i2c/i2c-core-base.c @@ -190,10 +190,17 @@ int i2c_generic_scl_recovery(struct i2c_adapter *adap) if (bri->prepare_recovery) bri->prepare_recovery(adap); + /* + * If we can set SDA, we will always create a STOP to ensure additional + * pulses will do no harm. This is achieved by letting SDA follow SCL + * half a cycle later. Check the 'incomplete_write_byte' fault injector + * for details. + */ bri->set_scl(adap, scl); + ndelay(RECOVERY_NDELAY / 2); if (bri->set_sda) - bri->set_sda(adap, 1); - ndelay(RECOVERY_NDELAY); + bri->set_sda(adap, scl); + ndelay(RECOVERY_NDELAY / 2); /* * By this time SCL is high, as we need to give 9 falling-rising edges @@ -211,13 +218,7 @@ int i2c_generic_scl_recovery(struct i2c_adapter *adap) scl = !scl; bri->set_scl(adap, scl); - - /* - * If we can set SDA, we will always create STOP here to ensure - * the additional pulses will do no harm. This is achieved by - * letting SDA follow SCL half a cycle later. Check the - * 'incomplete_write_byte' fault injector for details. - */ + /* Creating STOP again, see above */ ndelay(RECOVERY_NDELAY / 2); if (bri->set_sda) bri->set_sda(adap, scl); |