diff --git a/sys/arch/sh3/dev/adc.c b/sys/arch/sh3/dev/adc.c
new file mode 100644
index 000000000000..e8300588b26f
--- /dev/null
+++ b/sys/arch/sh3/dev/adc.c
@@ -0,0 +1,173 @@
+/*	$NetBSD: adc.c,v 1.1 2003/10/18 01:27:18 uwe Exp $ */
+
+/*
+ * Copyright (c) 2003 Valeriy E. Ushakov
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/param.h>
+#include <sys/kernel.h>
+#include <sys/device.h>
+#include <sys/malloc.h>
+#include <sys/systm.h>
+#ifdef GPROF
+#include <sys/gmon.h>
+#endif
+
+#include <sh3/adcreg.h>
+
+#define ADC_(x)    (*((volatile uint8_t *)SH7709_AD ## x))
+
+
+struct adc_softc {
+	struct device sc_dev;
+};
+
+static int	adc_match(struct device *, struct cfdata *, void *);
+static void	adc_attach(struct device *, struct device *, void *);
+
+CFATTACH_DECL(adc, sizeof(struct adc_softc),
+    adc_match, adc_attach, NULL, NULL);
+
+static int	adc_search(struct device *, struct cfdata *, void *);
+static int	adc_print(void *, const char *);
+
+extern int	adc_sample_channel(int); /* XXX: adcvar.h */
+
+
+static int
+adc_match(struct device *parent, struct cfdata *cfp, void *aux)
+{
+
+	/* REMINDER: also in 7727 and 7729 */
+	if ((cpu_product != CPU_PRODUCT_7709)
+	    && (cpu_product != CPU_PRODUCT_7709A))
+		return (0);
+
+	if (strcmp(cfp->cf_name, "adc") != 0)
+		return (0);
+
+	return (1);
+}
+
+
+static void
+adc_attach(struct device *parent, struct device *self, void *aux)
+{
+	/* struct adc_softc *sc = (struct adc_softc *)self; */
+
+	ADC_(CSR) = 0;
+	ADC_(CR) = 0;
+
+	printf("\n");
+	config_search(adc_search, self, NULL);
+}
+
+
+static int
+adc_search(struct device *parent, struct cfdata *cf, void *aux)
+{
+
+	if (config_match(parent, cf, NULL) > 0)
+		config_attach(parent, cf, NULL, adc_print);
+
+	return (0);
+}
+
+
+static int
+adc_print(void *aux, const char *pnp)
+{
+
+	return (pnp ? QUIET : UNCONF);
+}
+
+
+/*
+ * Sample specified ADC channel.
+ * Must be called at spltty().
+ */
+int
+adc_sample_channel(int chan)
+{
+	volatile uint8_t *hireg;
+	volatile uint8_t *loreg;
+	int regoff;
+	uint8_t csr;
+	int timo;
+#ifdef DIAGNOSTIC
+	uint8_t cr;
+	char bits[128];
+#endif
+	if ((chan < 0) || (chan >= 8))
+		return (-1);
+
+	regoff = (chan & 0x03) << 2;
+	hireg = (volatile uint8_t *)(SH7709_ADDRAH + regoff);
+	loreg = (volatile uint8_t *)(SH7709_ADDRAL + regoff);
+
+	/* the loop below typically takes 27 iterations on j680 */
+	timo = 300;
+
+#ifdef DIAGNOSTIC
+	csr = ADC_(CSR);
+	if ((csr & SH7709_ADCSR_ADST) != 0) {
+		/* another conversion is in progress?! */
+		printf("adc_sample_channel(%d): CSR=%s", chan,
+		       bitmask_snprintf(csr, SH7709_ADCSR_BITS,
+					bits, sizeof(bits)));
+		cr = ADC_(CR);
+		cr &= ~0x07;	/* three lower bits always read as 1s */
+		printf(", CR=%s\n",
+		       bitmask_snprintf(cr, SH7709_ADCR_BITS,
+					bits, sizeof(bits)));
+		return (-1);
+	}
+#endif
+
+	/* start scanning */
+	ADC_(CSR) = chan | SH7709_ADCSR_ADST | SH7709_ADCSR_CKS;
+
+	do {
+		csr = ADC_(CSR);
+		if (timo-- == 0)
+			break;
+	} while ((csr & SH7709_ADCSR_ADF) == 0);
+
+	/* stop scanning */
+	csr &= ~(SH7709_ADCSR_ADF | SH7709_ADCSR_ADST);
+	ADC_(CSR) = csr;
+
+	if (timo <= 0) {
+		printf("adc_sample_channel(%d): timed out\n", chan);
+		return (-1);
+	}
+
+	/*
+	 * 10 bit of data: bits [9..2] in the high register, bits
+	 * [1..0] in the bits [7..6] of the low register.
+	 */
+	return (((*hireg << 8) | *loreg) >> 6);
+}