1<html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>struct spi_device</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="spi.html" title="Chapter 10. Serial Peripheral Interface (SPI)"><link rel="prev" href="API-struct-spi-statistics.html" title="struct spi_statistics"><link rel="next" href="API-struct-spi-driver.html" title="struct spi_driver"></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">struct spi_device</span></th></tr><tr><td width="20%" align="left"><a accesskey="p" href="API-struct-spi-statistics.html">Prev</a> </td><th width="60%" align="center">Chapter 10. Serial Peripheral Interface (SPI)</th><td width="20%" align="right"> <a accesskey="n" href="API-struct-spi-driver.html">Next</a></td></tr></table><hr></div><div class="refentry"><a name="API-struct-spi-device"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>struct spi_device — 2 Master side proxy for an SPI slave device 3 </p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><pre class="programlisting"> 4struct spi_device { 5 struct device dev; 6 struct spi_master * master; 7 u32 max_speed_hz; 8 u8 chip_select; 9 u8 bits_per_word; 10 u16 mode; 11#define SPI_CPHA 0x01 12#define SPI_CPOL 0x02 13#define SPI_MODE_0 (0|0) 14#define SPI_MODE_1 (0|SPI_CPHA) 15#define SPI_MODE_2 (SPI_CPOL|0) 16#define SPI_MODE_3 (SPI_CPOL|SPI_CPHA) 17#define SPI_CS_HIGH 0x04 18#define SPI_LSB_FIRST 0x08 19#define SPI_3WIRE 0x10 20#define SPI_LOOP 0x20 21#define SPI_NO_CS 0x40 22#define SPI_READY 0x80 23#define SPI_TX_DUAL 0x100 24#define SPI_TX_QUAD 0x200 25#define SPI_RX_DUAL 0x400 26#define SPI_RX_QUAD 0x800 27 int irq; 28 void * controller_state; 29 void * controller_data; 30 char modalias[SPI_NAME_SIZE]; 31 int cs_gpio; 32 struct spi_statistics statistics; 33}; </pre></div><div class="refsect1"><a name="id-1.12.7.5"></a><h2>Members</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term">dev</span></dt><dd><p> 34 Driver model representation of the device. 35 </p></dd><dt><span class="term">master</span></dt><dd><p> 36 SPI controller used with the device. 37 </p></dd><dt><span class="term">max_speed_hz</span></dt><dd><p> 38 Maximum clock rate to be used with this chip 39 (on this board); may be changed by the device's driver. 40 The spi_transfer.speed_hz can override this for each transfer. 41 </p></dd><dt><span class="term">chip_select</span></dt><dd><p> 42 Chipselect, distinguishing chips handled by <em class="parameter"><code>master</code></em>. 43 </p></dd><dt><span class="term">bits_per_word</span></dt><dd><p> 44 Data transfers involve one or more words; word sizes 45 like eight or 12 bits are common. In-memory wordsizes are 46 powers of two bytes (e.g. 20 bit samples use 32 bits). 47 This may be changed by the device's driver, or left at the 48 default (0) indicating protocol words are eight bit bytes. 49 The spi_transfer.bits_per_word can override this for each transfer. 50 </p></dd><dt><span class="term">mode</span></dt><dd><p> 51 The spi mode defines how data is clocked out and in. 52 This may be changed by the device's driver. 53 The <span class="quote">“<span class="quote">active low</span>”</span> default for chipselect mode can be overridden 54 (by specifying SPI_CS_HIGH) as can the <span class="quote">“<span class="quote">MSB first</span>”</span> default for 55 each word in a transfer (by specifying SPI_LSB_FIRST). 56 </p></dd><dt><span class="term">irq</span></dt><dd><p> 57 Negative, or the number passed to <code class="function">request_irq</code> to receive 58 interrupts from this device. 59 </p></dd><dt><span class="term">controller_state</span></dt><dd><p> 60 Controller's runtime state 61 </p></dd><dt><span class="term">controller_data</span></dt><dd><p> 62 Board-specific definitions for controller, such as 63 FIFO initialization parameters; from board_info.controller_data 64 </p></dd><dt><span class="term">modalias[SPI_NAME_SIZE]</span></dt><dd><p> 65 Name of the driver to use with this device, or an alias 66 for that name. This appears in the sysfs <span class="quote">“<span class="quote">modalias</span>”</span> attribute 67 for driver coldplugging, and in uevents used for hotplugging 68 </p></dd><dt><span class="term">cs_gpio</span></dt><dd><p> 69 gpio number of the chipselect line (optional, -ENOENT when 70 when not using a GPIO line) 71 </p></dd><dt><span class="term">statistics</span></dt><dd><p> 72 statistics for the spi_device 73 </p></dd></dl></div></div><div class="refsect1"><a name="id-1.12.7.6"></a><h2>Description</h2><p> 74 A <em class="parameter"><code>spi_device</code></em> is used to interchange data between an SPI slave 75 (usually a discrete chip) and CPU memory. 76 </p><p> 77 78 In <em class="parameter"><code>dev</code></em>, the platform_data is used to hold information about this 79 device that's meaningful to the device's protocol driver, but not 80 to its controller. One example might be an identifier for a chip 81 variant with slightly different functionality; another might be 82 information about how this particular board wires the chip's pins. 83</p></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="API-struct-spi-statistics.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="spi.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="API-struct-spi-driver.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top"><span class="phrase">struct spi_statistics</span> </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> <span class="phrase">struct spi_driver</span></td></tr></table></div></body></html> 84