1<html><head><meta http-equiv="Content-Type" content="text/html; charset=ANSI_X3.4-1968"><title>Hardware control function</title><meta name="generator" content="DocBook XSL Stylesheets V1.78.1"><link rel="home" href="index.html" title="MTD NAND Driver Programming Interface"><link rel="up" href="basicboarddriver.html" title="Chapter&#160;4.&#160;Basic board driver"><link rel="prev" href="Partition_defines.html" title="Partition defines"><link rel="next" href="Device_ready_function.html" title="Device ready function"></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">Hardware control function</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="Partition_defines.html">Prev</a>&#160;</td><th width="60%" align="center">Chapter&#160;4.&#160;Basic board driver</th><td width="20%" align="right">&#160;<a accesskey="n" href="Device_ready_function.html">Next</a></td></tr></table><hr></div><div class="sect1"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="Hardware_control_functions"></a>Hardware control function</h2></div></div></div><p>
2			The hardware control function provides access to the 
3			control pins of the NAND chip(s). 
4			The access can be done by GPIO pins or by address lines.
5			If you use address lines, make sure that the timing
6			requirements are met.
7		</p><p>
8			<span class="emphasis"><em>GPIO based example</em></span>
9		</p><pre class="programlisting">
10static void board_hwcontrol(struct mtd_info *mtd, int cmd)
11{
12	switch(cmd){
13		case NAND_CTL_SETCLE: /* Set CLE pin high */ break;
14		case NAND_CTL_CLRCLE: /* Set CLE pin low */ break;
15		case NAND_CTL_SETALE: /* Set ALE pin high */ break;
16		case NAND_CTL_CLRALE: /* Set ALE pin low */ break;
17		case NAND_CTL_SETNCE: /* Set nCE pin low */ break;
18		case NAND_CTL_CLRNCE: /* Set nCE pin high */ break;
19	}
20}
21		</pre><p>
22			<span class="emphasis"><em>Address lines based example.</em></span> It's assumed that the
23			nCE pin is driven by a chip select decoder.
24		</p><pre class="programlisting">
25static void board_hwcontrol(struct mtd_info *mtd, int cmd)
26{
27	struct nand_chip *this = (struct nand_chip *) mtd-&gt;priv;
28	switch(cmd){
29		case NAND_CTL_SETCLE: this-&gt;IO_ADDR_W |= CLE_ADRR_BIT;  break;
30		case NAND_CTL_CLRCLE: this-&gt;IO_ADDR_W &amp;= ~CLE_ADRR_BIT; break;
31		case NAND_CTL_SETALE: this-&gt;IO_ADDR_W |= ALE_ADRR_BIT;  break;
32		case NAND_CTL_CLRALE: this-&gt;IO_ADDR_W &amp;= ~ALE_ADRR_BIT; break;
33	}
34}
35		</pre></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="Partition_defines.html">Prev</a>&#160;</td><td width="20%" align="center"><a accesskey="u" href="basicboarddriver.html">Up</a></td><td width="40%" align="right">&#160;<a accesskey="n" href="Device_ready_function.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">Partition defines&#160;</td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top">&#160;Device ready function</td></tr></table></div></body></html>
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