diff options
Diffstat (limited to 'arch/sh/kernel/cpu/adc.c')
-rw-r--r-- | arch/sh/kernel/cpu/adc.c | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/arch/sh/kernel/cpu/adc.c b/arch/sh/kernel/cpu/adc.c new file mode 100644 index 00000000000..da3d6877f93 --- /dev/null +++ b/arch/sh/kernel/cpu/adc.c @@ -0,0 +1,36 @@ +/* + * 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 = ctrl_inb(ADCSR); + csr = channel | ADCSR_ADST | ADCSR_CKS; + ctrl_outb(csr, ADCSR); + + do { + csr = ctrl_inb(ADCSR); + } while ((csr & ADCSR_ADF) == 0); + + csr &= ~(ADCSR_ADF | ADCSR_ADST); + ctrl_outb(csr, ADCSR); + + return (((ctrl_inb(ADDRAH + off) << 8) | + ctrl_inb(ADDRAL + off)) >> 6); +} + +EXPORT_SYMBOL(adc_single); |