2 * Copyright (c) 2006 Sam Leffler. All rights reserved.
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
14 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
15 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
16 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
17 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
18 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
19 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
20 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
21 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
22 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 #include <sys/cdefs.h>
26 __FBSDID("$FreeBSD$");
28 * Analog Devices AD7418 chip sitting on the I2C bus.
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/kernel.h>
34 #include <sys/module.h>
35 #include <sys/mutex.h>
37 #include <sys/resource.h>
39 #include <sys/sysctl.h>
41 #include <machine/bus.h>
42 #include <machine/cpu.h>
43 #include <machine/cpufunc.h>
44 #include <machine/frame.h>
45 #include <machine/resource.h>
46 #include <machine/intr.h>
48 #include <dev/iicbus/iiconf.h>
50 #include "iicbus_if.h"
52 #define IIC_M_WR 0 /* write operation */
54 #define AD7418_ADDR 0x50 /* slave address */
56 #define AD7418_TEMP 0 /* Temperature Value (r/o) */
57 #define AD7418_CONF 1 /* Config Register (r/w) */
58 #define AD7418_CONF_SHUTDOWN 0x01
59 #define AD7418_CONF_CHAN 0xe0 /* channel select mask */
60 #define AD7418_CHAN_TEMP 0x00 /* temperature channel */
61 #define AD7418_CHAN_VOLT 0x80 /* voltage channel */
62 #define AD7418_THYST 2 /* Thyst Setpoint (r/o) */
63 #define AD7418_TOTI 3 /* Toti Setpoint */
64 #define AD7418_VOLT 4 /* ADC aka Voltage (r/o) */
65 #define AD7418_CONF2 5 /* Config2 Register (r/w) */
70 int sc_curchan; /* current channel */
73 int sc_lastupdate; /* in ticks */
76 static void ad7418_update(struct ad7418_softc *);
77 static int ad7418_read_1(device_t dev, int reg);
78 static int ad7418_write_1(device_t dev, int reg, int v);
81 ad7418_probe(device_t dev)
83 /* XXX really probe? */
84 device_set_desc(dev, "Analog Devices AD7418 ADC");
89 ad7418_sysctl_temp(SYSCTL_HANDLER_ARGS)
91 struct ad7418_softc *sc = arg1;
95 temp = (sc->sc_curtemp / 64) * 25;
96 return sysctl_handle_int(oidp, &temp, 0, req);
100 ad7418_sysctl_voltage(SYSCTL_HANDLER_ARGS)
102 struct ad7418_softc *sc = arg1;
106 volt = (sc->sc_curvolt >> 6) * 564 / 10;
107 return sysctl_handle_int(oidp, &volt, 0, req);
111 ad7418_attach(device_t dev)
113 struct ad7418_softc *sc = device_get_softc(dev);
114 struct sysctl_ctx_list *ctx = device_get_sysctl_ctx(dev);
115 struct sysctl_oid *tree = device_get_sysctl_tree(dev);
119 mtx_init(&sc->sc_mtx, "ad7418", "ad7418", MTX_DEF);
121 SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
122 "temp", CTLTYPE_INT | CTLFLAG_RD, sc, 0,
123 ad7418_sysctl_temp, "I", "operating temperature");
124 SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
125 "volt", CTLTYPE_INT | CTLFLAG_RD, sc, 0,
126 ad7418_sysctl_voltage, "I", "input voltage");
128 /* enable chip if configured in shutdown mode */
129 conf = ad7418_read_1(dev, AD7418_CONF);
130 if (conf >= 0 && (conf & AD7418_CONF_SHUTDOWN))
131 ad7418_write_1(dev, AD7418_CONF, conf &~ AD7418_CONF_SHUTDOWN);
137 ad7418_read_1(device_t dev, int reg)
141 struct iic_msg msgs[2] = {
142 { AD7418_ADDR, IIC_M_WR, 1, &addr },
143 { AD7418_ADDR, IIC_M_RD, 1, data },
145 return iicbus_transfer(dev, msgs, 2) != 0 ? -1 : data[0];
149 ad7418_write_1(device_t dev, int reg, int v)
151 /* NB: register pointer precedes actual data */
153 struct iic_msg msgs[1] = {
154 { AD7418_ADDR, IIC_M_WR, 2, data },
158 return iicbus_transfer(dev, msgs, 1);
162 ad7418_set_channel(struct ad7418_softc *sc, int chan)
164 if (sc->sc_curchan == chan)
166 ad7418_write_1(sc->sc_dev, AD7418_CONF,
167 (ad7418_read_1(sc->sc_dev, AD7418_CONF) &~ AD7418_CONF_CHAN)|chan);
168 sc->sc_curchan = chan;
171 * NB: Linux driver delays here but chip data sheet
172 * says nothing and things appear to work fine w/o
173 * a delay on channel change. If this is enabled
174 * be sure to account for losing the mutex below
177 mtx_assert(&sc->sc_mtx, MA_OWNED);
178 /* let channel change settle, 1 tick should be 'nuf (need ~1ms) */
179 msleep(sc, &sc->sc_mtx, 0, "ad7418", 1);
184 ad7418_read_2(device_t dev, int reg)
188 struct iic_msg msgs[2] = {
189 { AD7418_ADDR, IIC_M_WR, 1, &addr },
190 { AD7418_ADDR, IIC_M_RD, 2, data },
192 /* NB: D15..D8 precede D7..D0 per data sheet (Fig 12) */
193 return iicbus_transfer(dev, msgs, 2) != 0 ?
194 -1 : ((data[0] << 8) | data[1]);
198 ad7418_update(struct ad7418_softc *sc)
202 mtx_lock(&sc->sc_mtx);
203 /* NB: no point in updating any faster than the chip */
204 if (ticks - sc->sc_lastupdate > hz) {
205 ad7418_set_channel(sc, AD7418_CHAN_TEMP);
206 v = ad7418_read_2(sc->sc_dev, AD7418_TEMP);
209 ad7418_set_channel(sc, AD7418_CHAN_VOLT);
210 v = ad7418_read_2(sc->sc_dev, AD7418_VOLT);
213 sc->sc_lastupdate = ticks;
215 mtx_unlock(&sc->sc_mtx);
218 static device_method_t ad7418_methods[] = {
219 DEVMETHOD(device_probe, ad7418_probe),
220 DEVMETHOD(device_attach, ad7418_attach),
225 static driver_t ad7418_driver = {
228 sizeof(struct ad7418_softc),
230 static devclass_t ad7418_devclass;
232 DRIVER_MODULE(ad7418, iicbus, ad7418_driver, ad7418_devclass, 0, 0);
233 MODULE_VERSION(ad7418, 1);
234 MODULE_DEPEND(ad7418, iicbus, 1, 1, 1);