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/*-
* 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("$FreeBSD$");
/*
* Analog Devices AD7418 chip sitting on the I2C bus.
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/module.h>
#include <sys/bus.h>
#include <sys/resource.h>
#include <sys/rman.h>
#include <sys/sysctl.h>
#include <sys/sx.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"
#define IIC_M_WR 0 /* write operation */
#define AD7418_ADDR 0x50 /* slave address */
#define AD7418_TEMP 0 /* Temperature Value (r/o) */
#define AD7418_CONF 1 /* Config Register (r/w) */
#define AD7418_CONF_SHUTDOWN 0x01
#define AD7418_CONF_CHAN 0xe0 /* channel select mask */
#define AD7418_CHAN_TEMP 0x00 /* temperature channel */
#define AD7418_CHAN_VOLT 0x80 /* voltage channel */
#define AD7418_THYST 2 /* Thyst Setpoint (r/o) */
#define AD7418_TOTI 3 /* Toti Setpoint */
#define AD7418_VOLT 4 /* ADC aka Voltage (r/o) */
#define AD7418_CONF2 5 /* Config2 Register (r/w) */
struct ad7418_softc {
device_t sc_dev;
struct sx sc_lock;
int sc_curchan; /* current channel */
int sc_curtemp;
int sc_curvolt;
int sc_lastupdate; /* in ticks */
};
static void ad7418_update(struct ad7418_softc *);
static int ad7418_read_1(device_t dev, int reg);
static int ad7418_write_1(device_t dev, int reg, int v);
static int
ad7418_probe(device_t dev)
{
/* XXX really probe? */
device_set_desc(dev, "Analog Devices AD7418 ADC");
return (BUS_PROBE_NOWILDCARD);
}
static int
ad7418_sysctl_temp(SYSCTL_HANDLER_ARGS)
{
struct ad7418_softc *sc = arg1;
int temp;
sx_xlock(&sc->sc_lock);
ad7418_update(sc);
temp = (sc->sc_curtemp / 64) * 25;
sx_xunlock(&sc->sc_lock);
return sysctl_handle_int(oidp, &temp, 0, req);
}
static int
ad7418_sysctl_voltage(SYSCTL_HANDLER_ARGS)
{
struct ad7418_softc *sc = arg1;
int volt;
sx_xlock(&sc->sc_lock);
ad7418_update(sc);
volt = (sc->sc_curvolt >> 6) * 564 / 10;
sx_xunlock(&sc->sc_lock);
return sysctl_handle_int(oidp, &volt, 0, req);
}
static int
ad7418_attach(device_t dev)
{
struct ad7418_softc *sc = device_get_softc(dev);
struct sysctl_ctx_list *ctx = device_get_sysctl_ctx(dev);
struct sysctl_oid *tree = device_get_sysctl_tree(dev);
int conf;
sc->sc_dev = dev;
sx_init(&sc->sc_lock, "ad7418");
SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
"temp", CTLTYPE_INT | CTLFLAG_RD, sc, 0,
ad7418_sysctl_temp, "I", "operating temperature");
SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
"volt", CTLTYPE_INT | CTLFLAG_RD, sc, 0,
ad7418_sysctl_voltage, "I", "input voltage");
/* enable chip if configured in shutdown mode */
conf = ad7418_read_1(dev, AD7418_CONF);
if (conf >= 0 && (conf & AD7418_CONF_SHUTDOWN))
ad7418_write_1(dev, AD7418_CONF, conf &~ AD7418_CONF_SHUTDOWN);
return (0);
}
static int
ad7418_read_1(device_t dev, int reg)
{
uint8_t addr = reg;
uint8_t data[1];
struct iic_msg msgs[2] = {
{ AD7418_ADDR, IIC_M_WR, 1, &addr },
{ AD7418_ADDR, IIC_M_RD, 1, data },
};
return iicbus_transfer(dev, msgs, 2) != 0 ? -1 : data[0];
}
static int
ad7418_write_1(device_t dev, int reg, int v)
{
/* NB: register pointer precedes actual data */
uint8_t data[2];
struct iic_msg msgs[1] = {
{ AD7418_ADDR, IIC_M_WR, 2, data },
};
data[0] = reg;
data[1] = v & 0xff;
return iicbus_transfer(dev, msgs, 1);
}
static void
ad7418_set_channel(struct ad7418_softc *sc, int chan)
{
if (sc->sc_curchan == chan)
return;
ad7418_write_1(sc->sc_dev, AD7418_CONF,
(ad7418_read_1(sc->sc_dev, AD7418_CONF) &~ AD7418_CONF_CHAN)|chan);
sc->sc_curchan = chan;
#if 0
/*
* NB: Linux driver delays here but chip data sheet
* says nothing and things appear to work fine w/o
* a delay on channel change.
*/
/* let channel change settle, 1 tick should be 'nuf (need ~1ms) */
tsleep(sc, 0, "ad7418", hz/1000);
#endif
}
static int
ad7418_read_2(device_t dev, int reg)
{
uint8_t addr = reg;
uint8_t data[2];
struct iic_msg msgs[2] = {
{ AD7418_ADDR, IIC_M_WR, 1, &addr },
{ AD7418_ADDR, IIC_M_RD, 2, data },
};
/* NB: D15..D8 precede D7..D0 per data sheet (Fig 12) */
return iicbus_transfer(dev, msgs, 2) != 0 ?
-1 : ((data[0] << 8) | data[1]);
}
static void
ad7418_update(struct ad7418_softc *sc)
{
int v;
sx_assert(&sc->sc_lock, SA_XLOCKED);
/* NB: no point in updating any faster than the chip */
if (ticks - sc->sc_lastupdate > hz) {
ad7418_set_channel(sc, AD7418_CHAN_TEMP);
v = ad7418_read_2(sc->sc_dev, AD7418_TEMP);
if (v >= 0)
sc->sc_curtemp = v;
ad7418_set_channel(sc, AD7418_CHAN_VOLT);
v = ad7418_read_2(sc->sc_dev, AD7418_VOLT);
if (v >= 0)
sc->sc_curvolt = v;
sc->sc_lastupdate = ticks;
}
}
static device_method_t ad7418_methods[] = {
DEVMETHOD(device_probe, ad7418_probe),
DEVMETHOD(device_attach, ad7418_attach),
DEVMETHOD_END
};
static driver_t ad7418_driver = {
"ad7418",
ad7418_methods,
sizeof(struct ad7418_softc),
};
static devclass_t ad7418_devclass;
DRIVER_MODULE(ad7418, iicbus, ad7418_driver, ad7418_devclass, 0, 0);
MODULE_VERSION(ad7418, 1);
MODULE_DEPEND(ad7418, iicbus, 1, 1, 1);
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