i2c and clock driver for Dallas Semiconductor DS1672 RTC

MFC after:	1 month

1 files changed, 142 insertions, 0 deletions

diff --git a/sys/dev/iicbus/ds1672.c b/sys/dev/iicbus/ds1672.c
new file mode 100644
index 0000000..be62224
--- /dev/null
+++ b/sys/dev/iicbus/ds1672.c
@@ -0,0 +1,142 @@
+/*-
+ * Copyright (c) 2006 Sam Leffler.  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 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/cdefs.h>
+__FBSDID("$FreeBSD$");
+/*
+ * Dallas Semiconductor DS1672 RTC sitting on the I2C bus.
+ */
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/kernel.h>
+#include <sys/module.h>
+#include <sys/clock.h>
+#include <sys/time.h>
+#include <sys/bus.h>
+#include <sys/resource.h>
+#include <sys/rman.h>
+
+#include <machine/bus.h>
+#include <machine/cpu.h>
+#include <machine/cpufunc.h>
+#include <machine/frame.h>
+#include <machine/resource.h>
+#include <machine/intr.h>
+
+#include <dev/iicbus/iiconf.h>
+
+#include "iicbus_if.h"
+#include "clock_if.h"
+
+#define	IIC_M_WR	0	/* write operation */
+
+#define	DS1672_ADDR	0xd0	/* slave address */
+
+#define	DS1672_COUNTER	0	/* counter (bytes 0-3) */
+#define	DS1672_CTRL	4	/* control (1 byte) */
+#define	DS1672_TRICKLE	5	/* trickle charger (1 byte) */
+
+#define NANOSEC		1000000000
+
+struct ds1672_softc {
+	device_t		sc_dev;
+};
+
+static int
+ds1672_probe(device_t dev)
+{
+	/* XXX really probe? */
+	device_set_desc(dev, "Dallas Semiconductor DS1672 RTC");
+	return (0);
+}
+
+static int
+ds1672_attach(device_t dev)
+{
+	struct ds1672_softc *sc = device_get_softc(dev);
+
+	sc->sc_dev = dev;
+
+	clock_register(dev, 1000);
+	return (0);
+}
+
+static int
+ds1672_gettime(device_t dev, struct timespec *ts)
+{
+	uint8_t addr[1] = { DS1672_COUNTER };
+	uint8_t secs[4];
+	struct iic_msg msgs[2] = {
+	     { DS1672_ADDR, IIC_M_WR, 1, addr },
+	     { DS1672_ADDR, IIC_M_RD, 4, secs },
+	};
+	int error;
+
+	error = iicbus_transfer(dev, msgs, 2);
+	if (error == 0) {
+		/* counter has seconds since epoch */
+		ts->tv_sec = (secs[3] << 24) | (secs[2] << 16)
+			   | (secs[1] <<  8) | (secs[0] <<  0);
+		ts->tv_nsec = NANOSEC / 2;
+	}
+	return error;
+}
+
+static int
+ds1672_settime(device_t dev, struct timespec *ts)
+{
+	/* NB: register pointer precedes actual data */
+	uint8_t data[5] = { DS1672_COUNTER };
+	struct iic_msg msgs[1] = {
+	     { DS1672_ADDR, IIC_M_WR, 5, data },
+	};
+
+	data[1] = (ts->tv_sec >> 0) & 0xff;
+	data[2] = (ts->tv_sec >> 8) & 0xff;
+	data[3] = (ts->tv_sec >> 16) & 0xff;
+	data[4] = (ts->tv_sec >> 24) & 0xff;
+
+	return iicbus_transfer(dev, msgs, 1);
+}
+
+static device_method_t ds1672_methods[] = {
+	DEVMETHOD(device_probe,		ds1672_probe),
+	DEVMETHOD(device_attach,	ds1672_attach),
+
+	DEVMETHOD(clock_gettime,	ds1672_gettime),
+	DEVMETHOD(clock_settime,	ds1672_settime),
+
+	{0, 0},
+};
+
+static driver_t ds1672_driver = {
+	"ds1672",
+	ds1672_methods,
+	sizeof(struct ds1672_softc),
+};
+static devclass_t ds1672_devclass;
+
+DRIVER_MODULE(ds1672, iicbus, ds1672_driver, ds1672_devclass, 0, 0);
+MODULE_VERSION(ds1672, 1);
+MODULE_DEPEND(ds1672, iicbus, 1, 1, 1);