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From: Abhishek Sahu <absahu@codeaurora.org>
To: Andy Gross <andy.gross@linaro.org>, Wolfram Sang <wsa@the-dreams.de>
Cc: David Brown <david.brown@linaro.org>,
	Sricharan R <sricharan@codeaurora.org>,
	linux-arm-msm@vger.kernel.org, linux-soc@vger.kernel.org,
	linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org,
	Abhishek Sahu <absahu@codeaurora.org>
Subject: [PATCH 10/12] i2c: qup: send NACK for last read sub transfers
Date: Sat,  3 Feb 2018 13:28:15 +0530	[thread overview]
Message-ID: <1517644697-30806-11-git-send-email-absahu@codeaurora.org> (raw)
In-Reply-To: <1517644697-30806-1-git-send-email-absahu@codeaurora.org>

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>
---
 drivers/i2c/busses/i2c-qup.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-qup.c b/drivers/i2c/busses/i2c-qup.c
index ba717bb..edea3b9 100644
--- a/drivers/i2c/busses/i2c-qup.c
+++ b/drivers/i2c/busses/i2c-qup.c
@@ -113,6 +113,7 @@
 #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 */
@@ -609,7 +610,9 @@ 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;
 	}
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

  parent reply	other threads:[~2018-02-03  7:59 UTC|newest]

Thread overview: 47+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-02-03  7:58 [PATCH 00/12] Major code reorganization to make all i2c transfers working Abhishek Sahu
2018-02-03  7:58 ` [PATCH 01/12] i2c: qup: fixed releasing dma without flush operation completion Abhishek Sahu
2018-02-08 14:03   ` Sricharan R
2018-02-27 21:46   ` Christ, Austin
2018-02-27 22:24   ` Andy Gross
2018-02-03  7:58 ` [PATCH 02/12] i2c: qup: minor code reorganization for use_dma Abhishek Sahu
2018-02-27 21:48   ` Christ, Austin
2018-02-27 22:26   ` Andy Gross
2018-02-03  7:58 ` [PATCH 03/12] i2c: qup: remove redundant variables for BAM SG count Abhishek Sahu
2018-02-09  2:16   ` Sricharan R
2018-02-27 21:51   ` Christ, Austin
2018-02-27 22:28   ` Andy Gross
2018-02-03  7:58 ` [PATCH 04/12] i2c: qup: schedule EOT and FLUSH tags at the end of transfer Abhishek Sahu
2018-02-15 14:31   ` Sricharan R
2018-02-27 22:36   ` Andy Gross
2018-03-08 13:40     ` Abhishek Sahu
2018-02-03  7:58 ` [PATCH 05/12] i2c: qup: fix the transfer length for BAM rx EOT FLUSH tags Abhishek Sahu
2018-02-27 22:38   ` Andy Gross
2018-02-03  7:58 ` [PATCH 06/12] i2c: qup: proper error handling for i2c error in BAM mode Abhishek Sahu
2018-02-16  4:33   ` Sricharan R
2018-02-27 22:00   ` Christ, Austin
2018-02-27 22:58   ` Andy Gross
2018-03-12 12:34     ` Abhishek Sahu
2018-02-03  7:58 ` [PATCH 07/12] i2c: qup: use the complete transfer length to choose DMA mode Abhishek Sahu
2018-02-16  4:35   ` Sricharan R
2018-02-27 22:01   ` Christ, Austin
2018-02-27 22:59   ` Andy Gross
2018-02-03  7:58 ` [PATCH 08/12] i2c: qup: change completion timeout according to transfer length Abhishek Sahu
2018-02-16  4:48   ` Sricharan R
     [not found]     ` <6a1983c0ca81afce908f622a53abd563@codeaurora.org>
2018-02-27 23:05       ` Andy Gross
2018-02-03  7:58 ` [PATCH 09/12] i2c: qup: fix buffer overflow for multiple msg of maximum xfer len Abhishek Sahu
2018-02-16  5:21   ` Sricharan R
2018-02-27 22:06   ` Christ, Austin
2018-03-12 13:55     ` Abhishek Sahu
2018-02-27 23:15   ` Andy Gross
2018-03-12 12:28     ` Abhishek Sahu
2018-02-03  7:58 ` Abhishek Sahu [this message]
2018-02-16  5:39   ` [PATCH 10/12] i2c: qup: send NACK for last read sub transfers Sricharan R
2018-02-27 22:07   ` Christ, Austin
2018-02-27 23:17   ` Andy Gross
2018-02-03  7:58 ` [PATCH 11/12] i2c: qup: reorganization of driver code to remove polling for qup v1 Abhishek Sahu
2018-02-05 23:03   ` kbuild test robot
2018-02-16  7:44   ` Sricharan R
2018-02-03  7:58 ` [PATCH 12/12] i2c: qup: reorganization of driver code to remove polling for qup v2 Abhishek Sahu
2018-02-16 11:23   ` Sricharan R
2018-02-27 23:24   ` Christ, Austin
2018-03-12 13:58     ` Abhishek Sahu

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