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    <title>i.MX ProcessorsのトピックI2C bus communication error without ACK</title>
    <link>https://community.nxp.com/t5/i-MX-Processors/I2C-bus-communication-error-without-ACK/m-p/611494#M92323</link>
    <description>&lt;HTML&gt;&lt;HEAD&gt;&lt;/HEAD&gt;&lt;BODY&gt;&lt;P&gt;Hi! Support,&amp;nbsp;&lt;/P&gt;&lt;P&gt;We designed a camera sensor module based on OV7725 sensor. &amp;nbsp;We used i.MX6Q Sabresd board to develop the driver for Android 5.1.1 and Linux 3.14.52 kernel. &amp;nbsp;Unfortunately I have not been able to communicate with the sensor module. &amp;nbsp;Even though we tested OV5640 module on Sabresd board, we have not been able to use the same I2C configuration to communicate with OV7725 sensor. &amp;nbsp;I traced into the i2c-imx.c and found out there are errors generated from the following two functions:&amp;nbsp;i2c_imx_trx_complete and&amp;nbsp;i2c_imx_acked. &amp;nbsp;I also checked the content of I2C_I2SR and it generates 0xa1 and 0xa5 most of the time. &amp;nbsp;I suspect that OV7725 sensor does not support I2C protocol, but only SCCB protocol.&amp;nbsp;&lt;/P&gt;&lt;P&gt;In addition, I examine the code of i2c-imx.c. &amp;nbsp;It seems the code does not support&amp;nbsp;I2C_FUNC_PROTOCOL_MANGLING, &amp;nbsp;I2C_M_IGNORE_NAK and&amp;nbsp;I2C_M_NO_RD_ACK. &amp;nbsp;Could you kindly tell me how to accommodate the NO_ACK condition? &amp;nbsp;Should I change I2C driver completely? Thanks!&lt;/P&gt;&lt;P&gt;Vincent&lt;/P&gt;&lt;/BODY&gt;&lt;/HTML&gt;</description>
    <pubDate>Wed, 01 Mar 2017 13:58:42 GMT</pubDate>
    <dc:creator>vincentchou</dc:creator>
    <dc:date>2017-03-01T13:58:42Z</dc:date>
    <item>
      <title>I2C bus communication error without ACK</title>
      <link>https://community.nxp.com/t5/i-MX-Processors/I2C-bus-communication-error-without-ACK/m-p/611494#M92323</link>
      <description>&lt;HTML&gt;&lt;HEAD&gt;&lt;/HEAD&gt;&lt;BODY&gt;&lt;P&gt;Hi! Support,&amp;nbsp;&lt;/P&gt;&lt;P&gt;We designed a camera sensor module based on OV7725 sensor. &amp;nbsp;We used i.MX6Q Sabresd board to develop the driver for Android 5.1.1 and Linux 3.14.52 kernel. &amp;nbsp;Unfortunately I have not been able to communicate with the sensor module. &amp;nbsp;Even though we tested OV5640 module on Sabresd board, we have not been able to use the same I2C configuration to communicate with OV7725 sensor. &amp;nbsp;I traced into the i2c-imx.c and found out there are errors generated from the following two functions:&amp;nbsp;i2c_imx_trx_complete and&amp;nbsp;i2c_imx_acked. &amp;nbsp;I also checked the content of I2C_I2SR and it generates 0xa1 and 0xa5 most of the time. &amp;nbsp;I suspect that OV7725 sensor does not support I2C protocol, but only SCCB protocol.&amp;nbsp;&lt;/P&gt;&lt;P&gt;In addition, I examine the code of i2c-imx.c. &amp;nbsp;It seems the code does not support&amp;nbsp;I2C_FUNC_PROTOCOL_MANGLING, &amp;nbsp;I2C_M_IGNORE_NAK and&amp;nbsp;I2C_M_NO_RD_ACK. &amp;nbsp;Could you kindly tell me how to accommodate the NO_ACK condition? &amp;nbsp;Should I change I2C driver completely? Thanks!&lt;/P&gt;&lt;P&gt;Vincent&lt;/P&gt;&lt;/BODY&gt;&lt;/HTML&gt;</description>
      <pubDate>Wed, 01 Mar 2017 13:58:42 GMT</pubDate>
      <guid>https://community.nxp.com/t5/i-MX-Processors/I2C-bus-communication-error-without-ACK/m-p/611494#M92323</guid>
      <dc:creator>vincentchou</dc:creator>
      <dc:date>2017-03-01T13:58:42Z</dc:date>
    </item>
    <item>
      <title>Re: I2C bus communication error without ACK</title>
      <link>https://community.nxp.com/t5/i-MX-Processors/I2C-bus-communication-error-without-ACK/m-p/611495#M92324</link>
      <description>&lt;HTML&gt;&lt;HEAD&gt;&lt;/HEAD&gt;&lt;BODY&gt;&lt;P&gt;&lt;SPAN style="font-size: 10.0pt;"&gt;Look at the following page:&lt;/SPAN&gt;&lt;/P&gt;&lt;P&gt;&lt;SPAN style="font-size: 10.0pt;"&gt;&lt;A class="jive-link-thread-small" data-containerid="2004" data-containertype="14" data-objectid="313467" data-objecttype="1" href="https://community.nxp.com/thread/313467"&gt;https://community.nxp.com/thread/313467&lt;/A&gt;&lt;/SPAN&gt;&lt;/P&gt;&lt;P&gt;&lt;SPAN style="font-size: 10.0pt;"&gt;&amp;nbsp;&lt;/SPAN&gt;&lt;/P&gt;&lt;P&gt;&lt;SPAN style="font-size: 10.0pt;"&gt;This page shows that i.MX6 I2C and i.MX6 BSP can be used for camera connection using SCCB protocol.&lt;/SPAN&gt;&lt;/P&gt;&lt;P&gt;&lt;BR /&gt;Have a great day,&lt;BR /&gt;Pavel Chubakov&lt;/P&gt;&lt;P&gt;&lt;/P&gt;&lt;P&gt;-----------------------------------------------------------------------------------------------------------------------&lt;BR /&gt;Note: If this post answers your question, please click the Correct Answer button. Thank you!&lt;BR /&gt;-----------------------------------------------------------------------------------------------------------------------&lt;/P&gt;&lt;/BODY&gt;&lt;/HTML&gt;</description>
      <pubDate>Thu, 02 Mar 2017 15:26:35 GMT</pubDate>
      <guid>https://community.nxp.com/t5/i-MX-Processors/I2C-bus-communication-error-without-ACK/m-p/611495#M92324</guid>
      <dc:creator>Pavel</dc:creator>
      <dc:date>2017-03-02T15:26:35Z</dc:date>
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