[deliverable/linux.git] / arch / sh / kernel / cpu / adc.c

/*
 * linux/arch/sh/kernel/adc.c -- SH3 on-chip ADC support
 *
 *  Copyright (C) 2004  Andriy Skulysh <askulysh@image.kiev.ua>
 */

#include <linux/module.h>
#include <asm/adc.h>
#include <asm/io.h>


int adc_single(unsigned int channel)
{
	int off;
	unsigned char csr;

	if (channel >= 8) return -1;

	off = (channel & 0x03) << 2;

	csr = __raw_readb(ADCSR);
	csr = channel | ADCSR_ADST | ADCSR_CKS;
	__raw_writeb(csr, ADCSR);

	do {
		csr = __raw_readb(ADCSR);
	} while ((csr & ADCSR_ADF) == 0);

	csr &= ~(ADCSR_ADF | ADCSR_ADST);
	__raw_writeb(csr, ADCSR);

	return (((__raw_readb(ADDRAH + off) << 8) |
		__raw_readb(ADDRAL + off)) >> 6);
}

EXPORT_SYMBOL(adc_single);
Commit	Line	Data
1da177e4 LT	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
	12	int 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
9d56dd3b	21	csr = __raw_readb(ADCSR);
1da177e4	22	csr = channel \| ADCSR_ADST \| ADCSR_CKS;
9d56dd3b	23	__raw_writeb(csr, ADCSR);
1da177e4 LT	24
1da177e4 LT	25	do {
9d56dd3b	26	csr = __raw_readb(ADCSR);
1da177e4 LT	27	} while ((csr & ADCSR_ADF) == 0);
	28
	29	csr &= ~(ADCSR_ADF \| ADCSR_ADST);
9d56dd3b	30	__raw_writeb(csr, ADCSR);
1da177e4	31
9d56dd3b PM	32	return (((__raw_readb(ADDRAH + off) << 8) \|
9d56dd3b PM	33	__raw_readb(ADDRAL + off)) >> 6);
1da177e4 LT	34	}
	35
	36	EXPORT_SYMBOL(adc_single);