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| author | Noralf Trønnes <noralf@tronnes.org> | 2016-10-03 22:06:11 +0200 |
|---|---|---|
| committer | Wolfram Sang <wsa@the-dreams.de> | 2016-11-07 01:48:31 +0100 |
| commit | 8d2cc5cc6ee5c0fc48a96bb29af55fc700f66fdf (patch) | |
| tree | b8026ec13c23983bbf656e8dc08e3f0be83028ef /drivers/i2c | |
| parent | 23c9540b3ad1d7473fe40df80074d0fb0bf04869 (diff) | |
| download | talos-op-linux-8d2cc5cc6ee5c0fc48a96bb29af55fc700f66fdf.tar.gz talos-op-linux-8d2cc5cc6ee5c0fc48a96bb29af55fc700f66fdf.zip | |
i2c: bcm2835: Can't support I2C_M_IGNORE_NAK
The controller can't support this flag, so remove it.
Documentation/i2c/i2c-protocol states that all of the message is sent:
I2C_M_IGNORE_NAK:
Normally message is interrupted immediately if there is [NA] from the
client. Setting this flag treats any [NA] as [A], and all of
message is sent.
>From the BCM2835 ARM Peripherals datasheet:
The ERR field is set when the slave fails to acknowledge either
its address or a data byte written to it.
So when the controller doesn't receive an ack, it sets ERR and raises
an interrupt. In other words, the whole message is not sent.
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'drivers/i2c')
| -rw-r--r-- | drivers/i2c/busses/i2c-bcm2835.c | 4 |
1 files changed, 0 insertions, 4 deletions
diff --git a/drivers/i2c/busses/i2c-bcm2835.c b/drivers/i2c/busses/i2c-bcm2835.c index 54d510abd46a..565ef69ce614 100644 --- a/drivers/i2c/busses/i2c-bcm2835.c +++ b/drivers/i2c/busses/i2c-bcm2835.c @@ -212,10 +212,6 @@ static int bcm2835_i2c_xfer_msg(struct bcm2835_i2c_dev *i2c_dev, if (likely(!i2c_dev->msg_err)) return 0; - if ((i2c_dev->msg_err & BCM2835_I2C_S_ERR) && - (msg->flags & I2C_M_IGNORE_NAK)) - return 0; - dev_dbg(i2c_dev->dev, "i2c transfer failed: %x\n", i2c_dev->msg_err); if (i2c_dev->msg_err & BCM2835_I2C_S_ERR) |
