1<html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>i2c_smbus_read_i2c_block_data_or_emulated</title><meta name="generator" content="DocBook XSL Stylesheets V1.78.1"><link rel="home" href="index.html" title="Linux Device Drivers"><link rel="up" href="i2c.html" title="Chapter 11. I2C and SMBus Subsystem"><link rel="prev" href="API-i2c-smbus-xfer.html" title="i2c_smbus_xfer"><link rel="next" href="hsi.html" title="Chapter 12. High Speed Synchronous Serial Interface (HSI)"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center"><span class="phrase">i2c_smbus_read_i2c_block_data_or_emulated</span></th></tr><tr><td width="20%" align="left"><a accesskey="p" href="API-i2c-smbus-xfer.html">Prev</a> </td><th width="60%" align="center">Chapter 11. I<sup>2</sup>C and SMBus Subsystem</th><td width="20%" align="right"> <a accesskey="n" href="hsi.html">Next</a></td></tr></table><hr></div><div class="refentry"><a name="API-i2c-smbus-read-i2c-block-data-or-emulated"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>i2c_smbus_read_i2c_block_data_or_emulated — 
2     read block or emulate
3 </p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><div class="funcsynopsis"><table border="0" class="funcprototype-table" summary="Function synopsis" style="cellspacing: 0; cellpadding: 0;"><tr><td><code class="funcdef">s32 <b class="fsfunc">i2c_smbus_read_i2c_block_data_or_emulated </b>(</code></td><td><a class="link" href="API-struct-i2c-client.html" title="struct i2c_client">const struct i2c_client</a> * <var class="pdparam">client</var>, </td></tr><tr><td> </td><td>u8 <var class="pdparam">command</var>, </td></tr><tr><td> </td><td>u8 <var class="pdparam">length</var>, </td></tr><tr><td> </td><td>u8 * <var class="pdparam">values</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"> </div></div></div><div class="refsect1"><a name="id-1.13.40.5"></a><h2>Arguments</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><em class="parameter"><code>client</code></em></span></dt><dd><p>
4     Handle to slave device
5    </p></dd><dt><span class="term"><em class="parameter"><code>command</code></em></span></dt><dd><p>
6     Byte interpreted by slave
7    </p></dd><dt><span class="term"><em class="parameter"><code>length</code></em></span></dt><dd><p>
8     Size of data block; SMBus allows at most I2C_SMBUS_BLOCK_MAX bytes
9    </p></dd><dt><span class="term"><em class="parameter"><code>values</code></em></span></dt><dd><p>
10     Byte array into which data will be read; big enough to hold
11     the data returned by the slave.  SMBus allows at most
12     I2C_SMBUS_BLOCK_MAX bytes.
13    </p></dd></dl></div></div><div class="refsect1"><a name="id-1.13.40.6"></a><h2>Description</h2><p>
14   This executes the SMBus <span class="quote">“<span class="quote">block read</span>”</span> protocol if supported by the adapter.
15   If block read is not supported, it emulates it using either word or byte
16   read protocols depending on availability.
17   </p><p>
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19   The addresses of the I2C slave device that are accessed with this function
20   must be mapped to a linear region, so that a block read will have the same
21   effect as a byte read. Before using this function you must double-check
22   if the I2C slave does support exchanging a block transfer with a byte
23   transfer.
24</p></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="API-i2c-smbus-xfer.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="i2c.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="hsi.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top"><span class="phrase">i2c_smbus_xfer</span> </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> Chapter 12. High Speed Synchronous Serial Interface (HSI)</td></tr></table></div></body></html>
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