diff --git a/sys/dev/i2c/axp20x.c b/sys/dev/i2c/axp20x.c
new file mode 100644
index 000000000000..e0e1b2c2dc74
--- /dev/null
+++ b/sys/dev/i2c/axp20x.c
@@ -0,0 +1,123 @@
+/* $NetBSD: axp20x.c,v 1.1 2014/09/09 22:47:33 jmcneill Exp $ */
+
+/*-
+ * Copyright (c) 2014 Jared D. McNeill <jmcneill@invisible.ca>
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+ * ``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 FOUNDATION OR CONTRIBUTORS
+ * 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/cdefs.h>
+__KERNEL_RCSID(0, "$NetBSD: axp20x.c,v 1.1 2014/09/09 22:47:33 jmcneill Exp $");
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/device.h>
+#include <sys/conf.h>
+#include <sys/bus.h>
+#include <sys/kmem.h>
+
+#include <dev/i2c/i2cvar.h>
+
+#include <dev/sysmon/sysmonvar.h>
+
+#define AXP_TEMP_MON_REG	0x5e	/* 2 bytes */
+
+struct axp20x_softc {
+	device_t	sc_dev;
+	i2c_tag_t	sc_i2c;
+	i2c_addr_t	sc_addr;
+
+	struct sysmon_envsys *sc_sme;
+	envsys_data_t	sc_sensor_temp;
+};
+
+static int	axp20x_match(device_t, cfdata_t, void *);
+static void	axp20x_attach(device_t, device_t, void *);
+
+static void	axp20x_sensors_refresh(struct sysmon_envsys *, envsys_data_t *);
+static int	axp20x_read(struct axp20x_softc *, uint8_t, uint8_t *, size_t);
+
+CFATTACH_DECL_NEW(axp20x, sizeof(struct axp20x_softc),
+    axp20x_match, axp20x_attach, NULL, NULL);
+
+static int
+axp20x_match(device_t parent, cfdata_t match, void *aux)
+{
+	return 1;
+}
+
+static void
+axp20x_attach(device_t parent, device_t self, void *aux)
+{
+	struct axp20x_softc *sc = device_private(self);
+	struct i2c_attach_args *ia = aux;
+
+	sc->sc_dev = self;
+	sc->sc_i2c = ia->ia_tag;
+	sc->sc_addr = ia->ia_addr;
+
+	aprint_naive("\n");
+	aprint_normal("\n");
+
+	sc->sc_sme = sysmon_envsys_create();
+	sc->sc_sme->sme_name = device_xname(self);
+	sc->sc_sme->sme_cookie = sc;
+	sc->sc_sme->sme_refresh = axp20x_sensors_refresh;
+
+	sc->sc_sensor_temp.units = ENVSYS_STEMP;
+	sc->sc_sensor_temp.state = ENVSYS_SINVALID;
+	sc->sc_sensor_temp.flags = ENVSYS_FHAS_ENTROPY;
+	snprintf(sc->sc_sensor_temp.desc, sizeof(sc->sc_sensor_temp),
+	    "internal temperature");
+	sysmon_envsys_sensor_attach(sc->sc_sme, &sc->sc_sensor_temp);
+
+	sysmon_envsys_register(sc->sc_sme);
+}
+
+static void
+axp20x_sensors_refresh(struct sysmon_envsys *sme, envsys_data_t *edata)
+{
+	struct axp20x_softc *sc = sme->sme_cookie;
+	uint8_t buf[2];
+	int error;
+
+	iic_acquire_bus(sc->sc_i2c, 0);
+	error = axp20x_read(sc, AXP_TEMP_MON_REG, buf, sizeof(buf));
+	iic_release_bus(sc->sc_i2c, 0);
+
+	if (error) {
+		edata->state = ENVSYS_SINVALID;
+	} else {
+		/* between -144.7C and 264.8C, step +0.1C */
+		edata->value_cur = (((buf[0] << 4) | (buf[1] & 0xf)) - 1447)
+				   * 100000 + 273150000;
+		edata->state = ENVSYS_SVALID;
+	}
+}
+
+static int
+axp20x_read(struct axp20x_softc *sc, uint8_t reg, uint8_t *val, size_t len)
+{
+	return iic_smbus_block_read(sc->sc_i2c, sc->sc_addr,
+	    reg, val, len, 0);
+}
diff --git a/sys/dev/i2c/files.i2c b/sys/dev/i2c/files.i2c
index 6d6e6b0d3b86..3f316f988ede 100644
--- a/sys/dev/i2c/files.i2c
+++ b/sys/dev/i2c/files.i2c
@@ -1,4 +1,4 @@
-#	$NetBSD: files.i2c,v 1.55 2014/09/09 22:44:32 jmcneill Exp $
+#	$NetBSD: files.i2c,v 1.56 2014/09/09 22:47:33 jmcneill Exp $
 
 obsolete defflag	opt_i2cbus.h		I2C_SCAN
 define	i2cbus { }
@@ -215,3 +215,7 @@ device  mpl115a: sysmon_envsys
 attach  mpl115a at iic
 file    dev/i2c/mpl115a.c		mpl115a
 
+# AXP20x Power Management Unit
+device	axp20x: sysmon_envsys
+attach	axp20x at iic
+file	dev/i2c/axp20x.c			axp20x