diff options
| author |   Abhishek Sahu <absahu@codeaurora.org> | 2018-03-12 18:45:00 +0530 |
|---|---|---|
| committer |   Wolfram Sang <wsa@the-dreams.de> | 2018-03-24 13:20:41 +0100 |
| commit | f7714b4e451bdcb7918b9aad14af22684ceac638 (patch) | |
| tree | d34cdca03983c9ea0496575fe312a2e25ba3dfb7 /drivers/i2c | |
| parent | i2c: qup: fix buffer overflow for multiple msg of maximum xfer len (diff) | |
| download | linux-dev-f7714b4e451bdcb7918b9aad14af22684ceac638.tar.xz linux-dev-f7714b4e451bdcb7918b9aad14af22684ceac638.zip | |
i2c: qup: send NACK for last read sub transfers
According to I2c specification, “If a master-receiver sends a
repeated START condition, it sends a not-acknowledge (A) just
before the repeated START condition”. QUP v2 supports sending
of NACK without stop with QUP_TAG_V2_DATARD_NACK so added the
same.
Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
Reviewed-by: Austin Christ <austinwc@codeaurora.org>
Reviewed-by: Andy Gross <andy.gross@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'drivers/i2c')
| -rw-r--r-- | drivers/i2c/busses/i2c-qup.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/i2c/busses/i2c-qup.c b/drivers/i2c/busses/i2c-qup.c index 5bb7ebe70f3c..4ebd9226dd87 100644 --- a/drivers/i2c/busses/i2c-qup.c +++ b/drivers/i2c/busses/i2c-qup.c @@ -104,6 +104,7 @@ #define QUP_TAG_V2_DATAWR 0x82 #define QUP_TAG_V2_DATAWR_STOP 0x83 #define QUP_TAG_V2_DATARD 0x85 +#define QUP_TAG_V2_DATARD_NACK 0x86 #define QUP_TAG_V2_DATARD_STOP 0x87 /* Status, Error flags */ @@ -606,7 +607,9 @@ static int qup_i2c_set_tags(u8 *tags, struct qup_i2c_dev *qup, tags[len++] = QUP_TAG_V2_DATAWR_STOP; } else { if (msg->flags & I2C_M_RD) - tags[len++] = QUP_TAG_V2_DATARD; + tags[len++] = qup->blk.pos == (qup->blk.count - 1) ? + QUP_TAG_V2_DATARD_NACK : + QUP_TAG_V2_DATARD; else tags[len++] = QUP_TAG_V2_DATAWR; } |