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| 3 | * linux/arch/sh/kernel/adc.c -- SH3 on-chip ADC support
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| 4 | *
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| 5 | * Copyright (C) 2004 Andriy Skulysh <[email protected]>
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| 6 |
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| 7 |
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| 8 | #include <linux/module.h>
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| 9 | #include <asm/adc.h>
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| 10 | #include <asm/io.h>
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| 11 |
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| 12 |
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| 13 | int adc_single(unsigned int channel)
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| 14 | {
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| 15 | int off;
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| 16 | unsigned char csr;
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| 17 |
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| 18 | if (channel >= 8) return -1;
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| 19 |
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| 20 | off = (channel & 0x03) << 2;
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| 21 |
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| 22 | csr = __raw_readb(ADCSR);
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| 23 | csr = channel | ADCSR_ADST | ADCSR_CKS;
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| 24 | __raw_writeb(csr, ADCSR);
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| 25 |
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| 26 | do {
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| 27 | csr = __raw_readb(ADCSR);
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| 28 | } while ((csr & ADCSR_ADF) == 0);
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| 29 |
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| 30 | csr &= ~(ADCSR_ADF | ADCSR_ADST);
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| 31 | __raw_writeb(csr, ADCSR);
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| 32 |
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| 33 | return (((__raw_readb(ADDRAH + off) << 8) |
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| 34 | __raw_readb(ADDRAL + off)) >> 6);
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| 35 | }
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| 36 |
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| 37 | EXPORT_SYMBOL(adc_single);
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