// 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);