1/*
2 * linux/arch/sh/kernel/adc.c -- SH3 on-chip ADC support
3 *
4 *  Copyright (C) 2004  Andriy Skulysh <askulysh@image.kiev.ua>
5 */
6
7#include <linux/module.h>
8#include <asm/adc.h>
9#include <asm/io.h>
10
11
12int adc_single(unsigned int channel)
13{
14	int off;
15	unsigned char csr;
16
17	if (channel >= 8) return -1;
18
19	off = (channel & 0x03) << 2;
20
21	csr = __raw_readb(ADCSR);
22	csr = channel | ADCSR_ADST | ADCSR_CKS;
23	__raw_writeb(csr, ADCSR);
24
25	do {
26		csr = __raw_readb(ADCSR);
27	} while ((csr & ADCSR_ADF) == 0);
28
29	csr &= ~(ADCSR_ADF | ADCSR_ADST);
30	__raw_writeb(csr, ADCSR);
31
32	return (((__raw_readb(ADDRAH + off) << 8) |
33		__raw_readb(ADDRAL + off)) >> 6);
34}
35
36EXPORT_SYMBOL(adc_single);
37