Resguardo inicial

linux-7.2.3/arch/sh/kernel/cpu/adc.c

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+// 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);