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authorFugang Duan <B38611@freescale.com>2014-04-30 14:24:58 +0800
committerWolfram Sang <wsa@the-dreams.de>2014-06-02 19:18:18 +0200
commit054b62d9f25c903958749e4cea25261324a7a2a4 (patch)
tree6b9abde90746233a1a35c3a766b6986489397a64 /fs/fcntl.c
parent3d99beabf17506b9d48461d1677a61a430000ad7 (diff)
downloadop-kernel-dev-054b62d9f25c903958749e4cea25261324a7a2a4.zip
op-kernel-dev-054b62d9f25c903958749e4cea25261324a7a2a4.tar.gz
i2c: imx: fix the i2c bus hang issue when do repeat restart
Test i2c device Maxim max44009, datasheet is located at: http://www.maximintegrated.com/datasheet/index.mvp/id/7175 The max44009 support repeat operation like: read -> repeat restart -> read/write The current i2c imx host controller driver don't support this operation that causes i2c bus hang due to "MTX" is cleared in .i2c_imx_read(). If "read" is the last message there have no problem, so the current driver supports all SMbus operation like: write -> repeat restart -> read/write IMX i2c controller for master receiver has some limitation: - If it is the last byte for one operation, it must generate STOP signal before read I2DR to prevent controller from generating another clock cycle. - If it is the last byte in the read, and then do repeat restart, it must set "MTX" before read I2DR to prevent controller from generating another extra clock cycle. The patch is to fix the issue. Signed-off-by: Fugang Duan <B38611@freescale.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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