From mboxrd@z Thu Jan 1 00:00:00 1970 From: wsa@the-dreams.de (Wolfram Sang) Date: Sun, 24 Jan 2016 12:29:16 +0100 Subject: [PATCH V7 3/6] i2c: qup: Transfer each i2c_msg in i2c_msgs without a stop bit In-Reply-To: <1453197766-18976-4-git-send-email-sricharan@codeaurora.org> References: <1453197766-18976-1-git-send-email-sricharan@codeaurora.org> <1453197766-18976-4-git-send-email-sricharan@codeaurora.org> Message-ID: <20160124112915.GA1775@katana> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi, > "If this is the last message in a group, it is followed by a STOP. > Otherwise it is followed by the next @i2c_msg transaction segment, > beginning with a (repeated) START" This is correct. > So the expectation is that there is no 'STOP' bit inbetween individual > i2c_msg segments with repeated 'START'. The QUP i2c hardware has no way > to inform that there should not be a 'STOP' at the end of transaction. > The only way to implement this is to coalesce all the i2c_msg in i2c_msgs > in to one transaction and transfer them. Adding the support for the same. So, there will not be a REP_START condition on the bus? I am sorry to say that I can't accept this. A REP_START is a REP_START and nothing else. There are devices which will get confused if there is no real REP_START condition. Without knowing the HW in detail, can't you implement I2C_M_NOSTART and let the touchscreen driver use it via regmap? That would be the proper way (from what I understand). Regards, Wolfram -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 819 bytes Desc: Digital signature URL: