1 /*-
2 * Copyright (c) 2006 Sam Leffler. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
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.
12 *
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.
23 */
24
25 #include <sys/cdefs.h>
26 __FBSDID("$FreeBSD$");
27 /*
28 * Analog Devices AD7418 chip sitting on the I2C bus.
29 */
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/kernel.h>
33 #include <sys/lock.h>
34 #include <sys/module.h>
35 #include <sys/bus.h>
36 #include <sys/resource.h>
37 #include <sys/rman.h>
38 #include <sys/sysctl.h>
39 #include <sys/sx.h>
40
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>
47
48 #include <dev/iicbus/iiconf.h>
49
50 #include "iicbus_if.h"
51
52 #define IIC_M_WR 0 /* write operation */
53
54 #define AD7418_ADDR 0x50 /* slave address */
55
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) */
66
67 struct ad7418_softc {
68 device_t sc_dev;
69 struct sx sc_lock;
70 int sc_curchan; /* current channel */
71 int sc_curtemp;
72 int sc_curvolt;
73 int sc_lastupdate; /* in ticks */
74 };
75
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);
79
80 static int
ad7418_probe(device_t dev)81 ad7418_probe(device_t dev)
82 {
83 /* XXX really probe? */
84 device_set_desc(dev, "Analog Devices AD7418 ADC");
85 return (BUS_PROBE_NOWILDCARD);
86 }
87
88 static int
ad7418_sysctl_temp(SYSCTL_HANDLER_ARGS)89 ad7418_sysctl_temp(SYSCTL_HANDLER_ARGS)
90 {
91 struct ad7418_softc *sc = arg1;
92 int temp;
93
94 sx_xlock(&sc->sc_lock);
95 ad7418_update(sc);
96 temp = (sc->sc_curtemp / 64) * 25;
97 sx_xunlock(&sc->sc_lock);
98 return sysctl_handle_int(oidp, &temp, 0, req);
99 }
100
101 static int
ad7418_sysctl_voltage(SYSCTL_HANDLER_ARGS)102 ad7418_sysctl_voltage(SYSCTL_HANDLER_ARGS)
103 {
104 struct ad7418_softc *sc = arg1;
105 int volt;
106
107 sx_xlock(&sc->sc_lock);
108 ad7418_update(sc);
109 volt = (sc->sc_curvolt >> 6) * 564 / 10;
110 sx_xunlock(&sc->sc_lock);
111 return sysctl_handle_int(oidp, &volt, 0, req);
112 }
113
114 static int
ad7418_attach(device_t dev)115 ad7418_attach(device_t dev)
116 {
117 struct ad7418_softc *sc = device_get_softc(dev);
118 struct sysctl_ctx_list *ctx = device_get_sysctl_ctx(dev);
119 struct sysctl_oid *tree = device_get_sysctl_tree(dev);
120 int conf;
121
122 sc->sc_dev = dev;
123 sc->sc_lastupdate = ticks - hz;
124
125 sx_init(&sc->sc_lock, "ad7418");
126
127 SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
128 "temp", CTLTYPE_INT | CTLFLAG_RD, sc, 0,
129 ad7418_sysctl_temp, "I", "operating temperature");
130 SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
131 "volt", CTLTYPE_INT | CTLFLAG_RD, sc, 0,
132 ad7418_sysctl_voltage, "I", "input voltage");
133
134 /* enable chip if configured in shutdown mode */
135 conf = ad7418_read_1(dev, AD7418_CONF);
136 if (conf >= 0 && (conf & AD7418_CONF_SHUTDOWN))
137 ad7418_write_1(dev, AD7418_CONF, conf &~ AD7418_CONF_SHUTDOWN);
138
139 return (0);
140 }
141
142 static int
ad7418_read_1(device_t dev,int reg)143 ad7418_read_1(device_t dev, int reg)
144 {
145 uint8_t addr = reg;
146 uint8_t data[1];
147 struct iic_msg msgs[2] = {
148 { AD7418_ADDR, IIC_M_WR, 1, &addr },
149 { AD7418_ADDR, IIC_M_RD, 1, data },
150 };
151 return iicbus_transfer(dev, msgs, 2) != 0 ? -1 : data[0];
152 }
153
154 static int
ad7418_write_1(device_t dev,int reg,int v)155 ad7418_write_1(device_t dev, int reg, int v)
156 {
157 /* NB: register pointer precedes actual data */
158 uint8_t data[2];
159 struct iic_msg msgs[1] = {
160 { AD7418_ADDR, IIC_M_WR, 2, data },
161 };
162 data[0] = reg;
163 data[1] = v & 0xff;
164 return iicbus_transfer(dev, msgs, 1);
165 }
166
167 static void
ad7418_set_channel(struct ad7418_softc * sc,int chan)168 ad7418_set_channel(struct ad7418_softc *sc, int chan)
169 {
170 if (sc->sc_curchan == chan)
171 return;
172 ad7418_write_1(sc->sc_dev, AD7418_CONF,
173 (ad7418_read_1(sc->sc_dev, AD7418_CONF) &~ AD7418_CONF_CHAN)|chan);
174 sc->sc_curchan = chan;
175 #if 0
176 /*
177 * NB: Linux driver delays here but chip data sheet
178 * says nothing and things appear to work fine w/o
179 * a delay on channel change.
180 */
181 /* let channel change settle, 1 tick should be 'nuf (need ~1ms) */
182 tsleep(sc, 0, "ad7418", hz/1000);
183 #endif
184 }
185
186 static int
ad7418_read_2(device_t dev,int reg)187 ad7418_read_2(device_t dev, int reg)
188 {
189 uint8_t addr = reg;
190 uint8_t data[2];
191 struct iic_msg msgs[2] = {
192 { AD7418_ADDR, IIC_M_WR, 1, &addr },
193 { AD7418_ADDR, IIC_M_RD, 2, data },
194 };
195 /* NB: D15..D8 precede D7..D0 per data sheet (Fig 12) */
196 return iicbus_transfer(dev, msgs, 2) != 0 ?
197 -1 : ((data[0] << 8) | data[1]);
198 }
199
200 static void
ad7418_update(struct ad7418_softc * sc)201 ad7418_update(struct ad7418_softc *sc)
202 {
203 int v;
204
205 sx_assert(&sc->sc_lock, SA_XLOCKED);
206 /* NB: no point in updating any faster than the chip */
207 if (ticks - sc->sc_lastupdate > hz) {
208 ad7418_set_channel(sc, AD7418_CHAN_TEMP);
209 v = ad7418_read_2(sc->sc_dev, AD7418_TEMP);
210 if (v >= 0)
211 sc->sc_curtemp = v;
212 ad7418_set_channel(sc, AD7418_CHAN_VOLT);
213 v = ad7418_read_2(sc->sc_dev, AD7418_VOLT);
214 if (v >= 0)
215 sc->sc_curvolt = v;
216 sc->sc_lastupdate = ticks;
217 }
218 }
219
220 static device_method_t ad7418_methods[] = {
221 DEVMETHOD(device_probe, ad7418_probe),
222 DEVMETHOD(device_attach, ad7418_attach),
223
224 DEVMETHOD_END
225 };
226
227 static driver_t ad7418_driver = {
228 "ad7418",
229 ad7418_methods,
230 sizeof(struct ad7418_softc),
231 };
232 static devclass_t ad7418_devclass;
233
234 DRIVER_MODULE(ad7418, iicbus, ad7418_driver, ad7418_devclass, 0, 0);
235 MODULE_VERSION(ad7418, 1);
236 MODULE_DEPEND(ad7418, iicbus, 1, 1, 1);
237