1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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 __FBSDID("$FreeBSD$");
29 /*
30 * Analog Devices AD7418 chip sitting on the I2C bus.
31 */
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/kernel.h>
35 #include <sys/lock.h>
36 #include <sys/module.h>
37 #include <sys/bus.h>
38 #include <sys/sysctl.h>
39 #include <sys/sx.h>
40
41 #include <dev/iicbus/iiconf.h>
42
43 #include "iicbus_if.h"
44
45 #define IIC_M_WR 0 /* write operation */
46
47 #define AD7418_ADDR 0x50 /* slave address */
48
49 #define AD7418_TEMP 0 /* Temperature Value (r/o) */
50 #define AD7418_CONF 1 /* Config Register (r/w) */
51 #define AD7418_CONF_SHUTDOWN 0x01
52 #define AD7418_CONF_CHAN 0xe0 /* channel select mask */
53 #define AD7418_CHAN_TEMP 0x00 /* temperature channel */
54 #define AD7418_CHAN_VOLT 0x80 /* voltage channel */
55 #define AD7418_THYST 2 /* Thyst Setpoint (r/o) */
56 #define AD7418_TOTI 3 /* Toti Setpoint */
57 #define AD7418_VOLT 4 /* ADC aka Voltage (r/o) */
58 #define AD7418_CONF2 5 /* Config2 Register (r/w) */
59
60 struct ad7418_softc {
61 device_t sc_dev;
62 struct sx sc_lock;
63 int sc_curchan; /* current channel */
64 int sc_curtemp;
65 int sc_curvolt;
66 int sc_lastupdate; /* in ticks */
67 };
68
69 static void ad7418_update(struct ad7418_softc *);
70 static int ad7418_read_1(device_t dev, int reg);
71 static int ad7418_write_1(device_t dev, int reg, int v);
72
73 static int
74 ad7418_probe(device_t dev)
75 {
76 /* XXX really probe? */
77 device_set_desc(dev, "Analog Devices AD7418 ADC");
78 return (BUS_PROBE_NOWILDCARD);
79 }
80
81 static int
82 ad7418_sysctl_temp(SYSCTL_HANDLER_ARGS)
83 {
84 struct ad7418_softc *sc = arg1;
85 int temp;
86
87 sx_xlock(&sc->sc_lock);
88 ad7418_update(sc);
89 temp = (sc->sc_curtemp / 64) * 25;
90 sx_xunlock(&sc->sc_lock);
91 return sysctl_handle_int(oidp, &temp, 0, req);
92 }
93
94 static int
95 ad7418_sysctl_voltage(SYSCTL_HANDLER_ARGS)
96 {
97 struct ad7418_softc *sc = arg1;
98 int volt;
99
100 sx_xlock(&sc->sc_lock);
101 ad7418_update(sc);
102 volt = (sc->sc_curvolt >> 6) * 564 / 10;
103 sx_xunlock(&sc->sc_lock);
104 return sysctl_handle_int(oidp, &volt, 0, req);
105 }
106
107 static int
108 ad7418_attach(device_t dev)
109 {
110 struct ad7418_softc *sc = device_get_softc(dev);
111 struct sysctl_ctx_list *ctx = device_get_sysctl_ctx(dev);
112 struct sysctl_oid *tree = device_get_sysctl_tree(dev);
113 int conf;
114
115 sc->sc_dev = dev;
116 sc->sc_lastupdate = ticks - hz;
117
118 sx_init(&sc->sc_lock, "ad7418");
119
120 SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
121 "temp", CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_NEEDGIANT, sc, 0,
122 ad7418_sysctl_temp, "I", "operating temperature");
123 SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
124 "volt", CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_NEEDGIANT, sc, 0,
125 ad7418_sysctl_voltage, "I", "input voltage");
126
127 /* enable chip if configured in shutdown mode */
128 conf = ad7418_read_1(dev, AD7418_CONF);
129 if (conf >= 0 && (conf & AD7418_CONF_SHUTDOWN))
130 ad7418_write_1(dev, AD7418_CONF, conf &~ AD7418_CONF_SHUTDOWN);
131
132 return (0);
133 }
134
135 static int
136 ad7418_read_1(device_t dev, int reg)
137 {
138 uint8_t addr = reg;
139 uint8_t data[1];
140 struct iic_msg msgs[2] = {
141 { AD7418_ADDR, IIC_M_WR, 1, &addr },
142 { AD7418_ADDR, IIC_M_RD, 1, data },
143 };
144 return iicbus_transfer(dev, msgs, 2) != 0 ? -1 : data[0];
145 }
146
147 static int
148 ad7418_write_1(device_t dev, int reg, int v)
149 {
150 /* NB: register pointer precedes actual data */
151 uint8_t data[2];
152 struct iic_msg msgs[1] = {
153 { AD7418_ADDR, IIC_M_WR, 2, data },
154 };
155 data[0] = reg;
156 data[1] = v & 0xff;
157 return iicbus_transfer(dev, msgs, 1);
158 }
159
160 static void
161 ad7418_set_channel(struct ad7418_softc *sc, int chan)
162 {
163 if (sc->sc_curchan == chan)
164 return;
165 ad7418_write_1(sc->sc_dev, AD7418_CONF,
166 (ad7418_read_1(sc->sc_dev, AD7418_CONF) &~ AD7418_CONF_CHAN)|chan);
167 sc->sc_curchan = chan;
168 #if 0
169 /*
170 * NB: Linux driver delays here but chip data sheet
171 * says nothing and things appear to work fine w/o
172 * a delay on channel change.
173 */
174 /* let channel change settle, 1 tick should be 'nuf (need ~1ms) */
175 tsleep(sc, 0, "ad7418", hz/1000);
176 #endif
177 }
178
179 static int
180 ad7418_read_2(device_t dev, int reg)
181 {
182 uint8_t addr = reg;
183 uint8_t data[2];
184 struct iic_msg msgs[2] = {
185 { AD7418_ADDR, IIC_M_WR, 1, &addr },
186 { AD7418_ADDR, IIC_M_RD, 2, data },
187 };
188 /* NB: D15..D8 precede D7..D0 per data sheet (Fig 12) */
189 return iicbus_transfer(dev, msgs, 2) != 0 ?
190 -1 : ((data[0] << 8) | data[1]);
191 }
192
193 static void
194 ad7418_update(struct ad7418_softc *sc)
195 {
196 int v;
197
198 sx_assert(&sc->sc_lock, SA_XLOCKED);
199 /* NB: no point in updating any faster than the chip */
200 if (ticks - sc->sc_lastupdate > hz) {
201 ad7418_set_channel(sc, AD7418_CHAN_TEMP);
202 v = ad7418_read_2(sc->sc_dev, AD7418_TEMP);
203 if (v >= 0)
204 sc->sc_curtemp = v;
205 ad7418_set_channel(sc, AD7418_CHAN_VOLT);
206 v = ad7418_read_2(sc->sc_dev, AD7418_VOLT);
207 if (v >= 0)
208 sc->sc_curvolt = v;
209 sc->sc_lastupdate = ticks;
210 }
211 }
212
213 static device_method_t ad7418_methods[] = {
214 DEVMETHOD(device_probe, ad7418_probe),
215 DEVMETHOD(device_attach, ad7418_attach),
216
217 DEVMETHOD_END
218 };
219
220 static driver_t ad7418_driver = {
221 "ad7418",
222 ad7418_methods,
223 sizeof(struct ad7418_softc),
224 };
225
226 DRIVER_MODULE(ad7418, iicbus, ad7418_driver, 0, 0);
227 MODULE_VERSION(ad7418, 1);
228 MODULE_DEPEND(ad7418, iicbus, 1, 1, 1);
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