36 lines
673 B
C
36 lines
673 B
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);
|