diff options
Diffstat (limited to 'target/linux/ipq40xx/patches-4.14/088-0011-i2c-qup-send-NACK-for-last-read-sub-transfers.patch')
-rw-r--r-- | target/linux/ipq40xx/patches-4.14/088-0011-i2c-qup-send-NACK-for-last-read-sub-transfers.patch | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/target/linux/ipq40xx/patches-4.14/088-0011-i2c-qup-send-NACK-for-last-read-sub-transfers.patch b/target/linux/ipq40xx/patches-4.14/088-0011-i2c-qup-send-NACK-for-last-read-sub-transfers.patch new file mode 100644 index 0000000000..82973829f1 --- /dev/null +++ b/target/linux/ipq40xx/patches-4.14/088-0011-i2c-qup-send-NACK-for-last-read-sub-transfers.patch @@ -0,0 +1,43 @@ +From f7714b4e451bdcb7918b9aad14af22684ceac638 Mon Sep 17 00:00:00 2001 +From: Abhishek Sahu <absahu@codeaurora.org> +Date: Mon, 12 Mar 2018 18:45:00 +0530 +Subject: [PATCH 11/13] i2c: qup: send NACK for last read sub transfers +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit + +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> +--- + drivers/i2c/busses/i2c-qup.c | 5 ++++- + 1 file changed, 4 insertions(+), 1 deletion(-) + +--- 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, st + 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; + } |