1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * linux/arch/sh/kernel/adc.c -- SH3 on-chip ADC support |
4 | * |
5 | * Copyright (C) 2004 Andriy Skulysh <askulysh@image.kiev.ua> |
6 | */ |
7 | |
8 | #include <linux/module.h> |
9 | #include <asm/adc.h> |
10 | #include <asm/io.h> |
11 | |
12 | |
13 | int adc_single(unsigned int channel) |
14 | { |
15 | int off; |
16 | unsigned char csr; |
17 | |
18 | if (channel >= 8) return -1; |
19 | |
20 | off = (channel & 0x03) << 2; |
21 | |
22 | csr = __raw_readb(addr: ADCSR); |
23 | csr = channel | ADCSR_ADST | ADCSR_CKS; |
24 | __raw_writeb(val: csr, addr: ADCSR); |
25 | |
26 | do { |
27 | csr = __raw_readb(addr: ADCSR); |
28 | } while ((csr & ADCSR_ADF) == 0); |
29 | |
30 | csr &= ~(ADCSR_ADF | ADCSR_ADST); |
31 | __raw_writeb(val: csr, addr: ADCSR); |
32 | |
33 | return (((__raw_readb(ADDRAH + off) << 8) | |
34 | __raw_readb(ADDRAL + off)) >> 6); |
35 | } |
36 | |
37 | EXPORT_SYMBOL(adc_single); |
38 | |