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// SPDX-License-Identifier: GPL-2.0
/*
* 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);
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