38 lines
709 B
C
38 lines
709 B
C
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// SPDX-License-Identifier: GPL-2.0
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/*
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* linux/arch/sh/kernel/adc.c -- SH3 on-chip ADC support
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*
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* Copyright (C) 2004 Andriy Skulysh <askulysh@image.kiev.ua>
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*/
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#include <linux/module.h>
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#include <asm/adc.h>
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#include <asm/io.h>
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int adc_single(unsigned int channel)
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{
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int off;
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unsigned char csr;
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if (channel >= 8) return -1;
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off = (channel & 0x03) << 2;
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csr = __raw_readb(ADCSR);
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csr = channel | ADCSR_ADST | ADCSR_CKS;
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__raw_writeb(csr, ADCSR);
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do {
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csr = __raw_readb(ADCSR);
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} while ((csr & ADCSR_ADF) == 0);
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csr &= ~(ADCSR_ADF | ADCSR_ADST);
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__raw_writeb(csr, ADCSR);
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return (((__raw_readb(ADDRAH + off) << 8) |
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__raw_readb(ADDRAL + off)) >> 6);
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}
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EXPORT_SYMBOL(adc_single);
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