1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2006 Sam Leffler. All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27 #include <sys/cdefs.h>
28 /*
29 * Analog Devices AD7418 chip sitting on the I2C bus.
30 */
31 #include <sys/param.h>
32 #include <sys/systm.h>
33 #include <sys/kernel.h>
34 #include <sys/lock.h>
35 #include <sys/module.h>
36 #include <sys/bus.h>
37 #include <sys/sysctl.h>
38 #include <sys/sx.h>
39
40 #include <dev/iicbus/iiconf.h>
41
42 #include "iicbus_if.h"
43
44 #define IIC_M_WR 0 /* write operation */
45
46 #define AD7418_ADDR 0x50 /* slave address */
47
48 #define AD7418_TEMP 0 /* Temperature Value (r/o) */
49 #define AD7418_CONF 1 /* Config Register (r/w) */
50 #define AD7418_CONF_SHUTDOWN 0x01
51 #define AD7418_CONF_CHAN 0xe0 /* channel select mask */
52 #define AD7418_CHAN_TEMP 0x00 /* temperature channel */
53 #define AD7418_CHAN_VOLT 0x80 /* voltage channel */
54 #define AD7418_THYST 2 /* Thyst Setpoint (r/o) */
55 #define AD7418_TOTI 3 /* Toti Setpoint */
56 #define AD7418_VOLT 4 /* ADC aka Voltage (r/o) */
57 #define AD7418_CONF2 5 /* Config2 Register (r/w) */
58
59 struct ad7418_softc {
60 device_t sc_dev;
61 struct sx sc_lock;
62 int sc_curchan; /* current channel */
63 int sc_curtemp;
64 int sc_curvolt;
65 int sc_lastupdate; /* in ticks */
66 };
67
68 static void ad7418_update(struct ad7418_softc *);
69 static int ad7418_read_1(device_t dev, int reg);
70 static int ad7418_write_1(device_t dev, int reg, int v);
71
72 static int
ad7418_probe(device_t dev)73 ad7418_probe(device_t dev)
74 {
75 /* XXX really probe? */
76 device_set_desc(dev, "Analog Devices AD7418 ADC");
77 return (BUS_PROBE_NOWILDCARD);
78 }
79
80 static int
ad7418_sysctl_temp(SYSCTL_HANDLER_ARGS)81 ad7418_sysctl_temp(SYSCTL_HANDLER_ARGS)
82 {
83 struct ad7418_softc *sc = arg1;
84 int temp;
85
86 sx_xlock(&sc->sc_lock);
87 ad7418_update(sc);
88 temp = (sc->sc_curtemp / 64) * 25;
89 sx_xunlock(&sc->sc_lock);
90 return sysctl_handle_int(oidp, &temp, 0, req);
91 }
92
93 static int
ad7418_sysctl_voltage(SYSCTL_HANDLER_ARGS)94 ad7418_sysctl_voltage(SYSCTL_HANDLER_ARGS)
95 {
96 struct ad7418_softc *sc = arg1;
97 int volt;
98
99 sx_xlock(&sc->sc_lock);
100 ad7418_update(sc);
101 volt = (sc->sc_curvolt >> 6) * 564 / 10;
102 sx_xunlock(&sc->sc_lock);
103 return sysctl_handle_int(oidp, &volt, 0, req);
104 }
105
106 static int
ad7418_attach(device_t dev)107 ad7418_attach(device_t dev)
108 {
109 struct ad7418_softc *sc = device_get_softc(dev);
110 struct sysctl_ctx_list *ctx = device_get_sysctl_ctx(dev);
111 struct sysctl_oid *tree = device_get_sysctl_tree(dev);
112 int conf;
113
114 sc->sc_dev = dev;
115 sc->sc_lastupdate = ticks - hz;
116
117 sx_init(&sc->sc_lock, "ad7418");
118
119 SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
120 "temp", CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_NEEDGIANT, sc, 0,
121 ad7418_sysctl_temp, "I", "operating temperature");
122 SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
123 "volt", CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_NEEDGIANT, sc, 0,
124 ad7418_sysctl_voltage, "I", "input voltage");
125
126 /* enable chip if configured in shutdown mode */
127 conf = ad7418_read_1(dev, AD7418_CONF);
128 if (conf >= 0 && (conf & AD7418_CONF_SHUTDOWN))
129 ad7418_write_1(dev, AD7418_CONF, conf &~ AD7418_CONF_SHUTDOWN);
130
131 return (0);
132 }
133
134 static int
ad7418_read_1(device_t dev,int reg)135 ad7418_read_1(device_t dev, int reg)
136 {
137 uint8_t addr = reg;
138 uint8_t data[1];
139 struct iic_msg msgs[2] = {
140 { AD7418_ADDR, IIC_M_WR, 1, &addr },
141 { AD7418_ADDR, IIC_M_RD, 1, data },
142 };
143 return iicbus_transfer(dev, msgs, 2) != 0 ? -1 : data[0];
144 }
145
146 static int
ad7418_write_1(device_t dev,int reg,int v)147 ad7418_write_1(device_t dev, int reg, int v)
148 {
149 /* NB: register pointer precedes actual data */
150 uint8_t data[2];
151 struct iic_msg msgs[1] = {
152 { AD7418_ADDR, IIC_M_WR, 2, data },
153 };
154 data[0] = reg;
155 data[1] = v & 0xff;
156 return iicbus_transfer(dev, msgs, 1);
157 }
158
159 static void
ad7418_set_channel(struct ad7418_softc * sc,int chan)160 ad7418_set_channel(struct ad7418_softc *sc, int chan)
161 {
162 if (sc->sc_curchan == chan)
163 return;
164 ad7418_write_1(sc->sc_dev, AD7418_CONF,
165 (ad7418_read_1(sc->sc_dev, AD7418_CONF) &~ AD7418_CONF_CHAN)|chan);
166 sc->sc_curchan = chan;
167 #if 0
168 /*
169 * NB: Linux driver delays here but chip data sheet
170 * says nothing and things appear to work fine w/o
171 * a delay on channel change.
172 */
173 /* let channel change settle, 1 tick should be 'nuf (need ~1ms) */
174 tsleep(sc, 0, "ad7418", hz/1000);
175 #endif
176 }
177
178 static int
ad7418_read_2(device_t dev,int reg)179 ad7418_read_2(device_t dev, int reg)
180 {
181 uint8_t addr = reg;
182 uint8_t data[2];
183 struct iic_msg msgs[2] = {
184 { AD7418_ADDR, IIC_M_WR, 1, &addr },
185 { AD7418_ADDR, IIC_M_RD, 2, data },
186 };
187 /* NB: D15..D8 precede D7..D0 per data sheet (Fig 12) */
188 return iicbus_transfer(dev, msgs, 2) != 0 ?
189 -1 : ((data[0] << 8) | data[1]);
190 }
191
192 static void
ad7418_update(struct ad7418_softc * sc)193 ad7418_update(struct ad7418_softc *sc)
194 {
195 int v;
196
197 sx_assert(&sc->sc_lock, SA_XLOCKED);
198 /* NB: no point in updating any faster than the chip */
199 if (ticks - sc->sc_lastupdate > hz) {
200 ad7418_set_channel(sc, AD7418_CHAN_TEMP);
201 v = ad7418_read_2(sc->sc_dev, AD7418_TEMP);
202 if (v >= 0)
203 sc->sc_curtemp = v;
204 ad7418_set_channel(sc, AD7418_CHAN_VOLT);
205 v = ad7418_read_2(sc->sc_dev, AD7418_VOLT);
206 if (v >= 0)
207 sc->sc_curvolt = v;
208 sc->sc_lastupdate = ticks;
209 }
210 }
211
212 static device_method_t ad7418_methods[] = {
213 DEVMETHOD(device_probe, ad7418_probe),
214 DEVMETHOD(device_attach, ad7418_attach),
215
216 DEVMETHOD_END
217 };
218
219 static driver_t ad7418_driver = {
220 "ad7418",
221 ad7418_methods,
222 sizeof(struct ad7418_softc),
223 };
224
225 DRIVER_MODULE(ad7418, iicbus, ad7418_driver, 0, 0);
226 MODULE_VERSION(ad7418, 1);
227 MODULE_DEPEND(ad7418, iicbus, 1, 1, 1);
228