diff options
Diffstat (limited to 'arch/sh/kernel/cpu/adc.c')
-rw-r--r-- | arch/sh/kernel/cpu/adc.c | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/arch/sh/kernel/cpu/adc.c b/arch/sh/kernel/cpu/adc.c new file mode 100644 index 000000000..509136715 --- /dev/null +++ b/arch/sh/kernel/cpu/adc.c @@ -0,0 +1,37 @@ +// 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); |