linux-sg2042/arch/sh/kernel/cpu/adc.c

37 lines
655 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 = ctrl_inb(ADCSR);
csr = channel | ADCSR_ADST | ADCSR_CKS;
ctrl_outb(csr, ADCSR);
do {
csr = ctrl_inb(ADCSR);
} while ((csr & ADCSR_ADF) == 0);
csr &= ~(ADCSR_ADF | ADCSR_ADST);
ctrl_outb(csr, ADCSR);
return (((ctrl_inb(ADDRAH + off) << 8) |
ctrl_inb(ADDRAL + off)) >> 6);
}
EXPORT_SYMBOL(adc_single);