Line data Source code
1 : /* $OpenBSD: owsbm.c,v 1.10 2015/03/14 03:38:48 jsg Exp $ */
2 :
3 : /*
4 : * Copyright (c) 2007 Aaron Linville <aaron@linville.org>
5 : *
6 : * Permission to use, copy, modify, and distribute this software for any
7 : * purpose with or without fee is hereby granted, provided that the above
8 : * copyright notice and this permission notice appear in all copies.
9 : *
10 : * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 : * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 : * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 : * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 : * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 : * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 : * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 : */
18 :
19 : /*
20 : * 1-Wire Smart Battery Monitor family type device driver.
21 : * Provides on-board temperature, an A/D converter for voltage/current,
22 : * current accumulator, elapsed time metter, and 40 bytes of nonvolatile
23 : * memory.
24 : */
25 :
26 : #include <sys/param.h>
27 : #include <sys/systm.h>
28 : #include <sys/device.h>
29 : #include <sys/rwlock.h>
30 : #include <sys/sensors.h>
31 :
32 : #include <dev/onewire/onewiredevs.h>
33 : #include <dev/onewire/onewirereg.h>
34 : #include <dev/onewire/onewirevar.h>
35 :
36 : /* Commands */
37 : #define DSSBM_CMD_READ_SCRATCHPAD 0xbe
38 : #define DSSBM_CMD_WRITE_SCRATCHPAD 0x4e
39 : #define DSSBM_CMD_COPY_SCRATCHPAD 0x48
40 :
41 : #define DSSBM_CMD_RECALL_MEMORY 0xb8
42 :
43 : #define DSSBM_CMD_CONVERT_T 0x44
44 : #define DSSBM_CMD_CONVERT_V 0xb4
45 :
46 : /* Scratchpad layout */
47 : #define DS2438_SP_STATUS 0
48 : #define DS2438_SP_TEMP_LSB 1
49 : #define DS2438_SP_TEMP_MSB 2
50 : #define DS2438_SP_VOLT_LSB 3
51 : #define DS2438_SP_VOLT_MSB 4
52 : #define DS2438_SP_CURRENT_LSB 5
53 : #define DS2438_SP_CURRENT_MSB 6
54 : #define DS2438_SP_THRESHOLD 7
55 : #define DS2438_SP_CRC 8
56 :
57 : struct owsbm_softc {
58 : struct device sc_dev;
59 :
60 : void * sc_onewire;
61 : u_int64_t sc_rom;
62 :
63 : struct ksensordev sc_sensordev;
64 :
65 : struct ksensor sc_temp;
66 : struct ksensor sc_voltage_vdd; /* Battery, AD = 1*/
67 : struct ksensor sc_voltage_vad; /* General purpose, AD = 0 */
68 : struct ksensor sc_voltage_cr; /* Current Register */
69 :
70 : struct sensor_task *sc_sensortask;
71 :
72 : struct rwlock sc_lock;
73 : };
74 :
75 : int owsbm_match(struct device *, void *, void *);
76 : void owsbm_attach(struct device *, struct device *, void *);
77 : int owsbm_detach(struct device *, int);
78 : int owsbm_activate(struct device *, int);
79 :
80 : void owsbm_update(void *);
81 :
82 : struct cfattach owsbm_ca = {
83 : sizeof(struct owsbm_softc),
84 : owsbm_match,
85 : owsbm_attach,
86 : owsbm_detach,
87 : owsbm_activate
88 : };
89 :
90 : struct cfdriver owsbm_cd = {
91 : NULL, "owsbm", DV_DULL
92 : };
93 :
94 : static const struct onewire_matchfam owsbm_fams[] = {
95 : { ONEWIRE_FAMILY_DS2438 }
96 : };
97 :
98 : int
99 0 : owsbm_match(struct device *parent, void *match, void *aux)
100 : {
101 0 : return (onewire_matchbyfam(aux, owsbm_fams, nitems(owsbm_fams)));
102 : }
103 :
104 : void
105 0 : owsbm_attach(struct device *parent, struct device *self, void *aux)
106 : {
107 0 : struct owsbm_softc *sc = (struct owsbm_softc *)self;
108 0 : struct onewire_attach_args *oa = aux;
109 :
110 0 : sc->sc_onewire = oa->oa_onewire;
111 0 : sc->sc_rom = oa->oa_rom;
112 :
113 : /* Initialize temp sensor */
114 0 : strlcpy(sc->sc_sensordev.xname, sc->sc_dev.dv_xname,
115 : sizeof(sc->sc_sensordev.xname));
116 0 : sc->sc_temp.type = SENSOR_TEMP;
117 0 : snprintf(sc->sc_temp.desc, sizeof(sc->sc_temp.desc), "sn %012llx",
118 0 : ONEWIRE_ROM_SN(oa->oa_rom));
119 0 : sensor_attach(&sc->sc_sensordev, &sc->sc_temp);
120 :
121 : /* Initialize voltage sensor */
122 0 : sc->sc_voltage_vdd.type = SENSOR_VOLTS_DC;
123 0 : strlcpy(sc->sc_voltage_vdd.desc, "VDD", sizeof(sc->sc_voltage_vdd.desc));
124 0 : sensor_attach(&sc->sc_sensordev, &sc->sc_voltage_vdd);
125 :
126 : /* Initialize voltage sensor */
127 0 : sc->sc_voltage_vad.type = SENSOR_VOLTS_DC;
128 0 : strlcpy(sc->sc_voltage_vad.desc, "VAD", sizeof(sc->sc_voltage_vad.desc));
129 0 : sensor_attach(&sc->sc_sensordev, &sc->sc_voltage_vad);
130 :
131 : /* Initialize the current sensor */
132 0 : sc->sc_voltage_cr.type = SENSOR_VOLTS_DC;
133 0 : strlcpy(sc->sc_voltage_cr.desc, "CR", sizeof(sc->sc_voltage_cr.desc));
134 0 : sensor_attach(&sc->sc_sensordev, &sc->sc_voltage_cr);
135 :
136 0 : sc->sc_sensortask = sensor_task_register(sc, owsbm_update, 10);
137 0 : if (sc->sc_sensortask == NULL) {
138 0 : printf(": unable to register update task\n");
139 0 : return;
140 : }
141 :
142 0 : sensordev_install(&sc->sc_sensordev);
143 :
144 0 : rw_init(&sc->sc_lock, sc->sc_dev.dv_xname);
145 0 : printf("\n");
146 0 : }
147 :
148 : int
149 0 : owsbm_detach(struct device *self, int flags)
150 : {
151 0 : struct owsbm_softc *sc = (struct owsbm_softc *)self;
152 :
153 0 : rw_enter_write(&sc->sc_lock);
154 0 : sensordev_deinstall(&sc->sc_sensordev);
155 0 : if (sc->sc_sensortask != NULL)
156 0 : sensor_task_unregister(sc->sc_sensortask);
157 0 : rw_exit_write(&sc->sc_lock);
158 :
159 0 : return (0);
160 : }
161 :
162 : int
163 0 : owsbm_activate(struct device *self, int act)
164 : {
165 0 : return (0);
166 : }
167 :
168 : void
169 0 : owsbm_update(void *arg)
170 : {
171 0 : struct owsbm_softc *sc = arg;
172 0 : u_int8_t data[9];
173 :
174 0 : rw_enter_write(&sc->sc_lock);
175 0 : onewire_lock(sc->sc_onewire, 0);
176 0 : if (onewire_reset(sc->sc_onewire) != 0)
177 : goto done;
178 :
179 0 : onewire_matchrom(sc->sc_onewire, sc->sc_rom);
180 0 : onewire_write_byte(sc->sc_onewire, DSSBM_CMD_CONVERT_T);
181 0 : if (onewire_reset(sc->sc_onewire) != 0)
182 : goto done;
183 :
184 0 : onewire_matchrom(sc->sc_onewire, sc->sc_rom);
185 0 : onewire_write_byte(sc->sc_onewire, DSSBM_CMD_CONVERT_V);
186 0 : if (onewire_reset(sc->sc_onewire) != 0)
187 : goto done;
188 :
189 0 : onewire_matchrom(sc->sc_onewire, sc->sc_rom);
190 : /* Issue Recall Memory page 00h cmd */
191 0 : onewire_write_byte(sc->sc_onewire, DSSBM_CMD_RECALL_MEMORY);
192 0 : onewire_write_byte(sc->sc_onewire, 0);
193 :
194 0 : if (onewire_reset(sc->sc_onewire) != 0)
195 : goto done;
196 :
197 0 : onewire_matchrom(sc->sc_onewire, sc->sc_rom);
198 : /* Read page 0 of Memory Map from Scratchpad */
199 0 : onewire_write_byte(sc->sc_onewire, DSSBM_CMD_READ_SCRATCHPAD);
200 0 : onewire_write_byte(sc->sc_onewire, 0);
201 0 : onewire_read_block(sc->sc_onewire, data, 9);
202 0 : if (onewire_crc(data, 8) == data[DS2438_SP_CRC]) {
203 0 : sc->sc_temp.value = 273150000 +
204 0 : (int)(((u_int16_t)data[DS2438_SP_TEMP_MSB] << 5) |
205 0 : ((u_int16_t)data[DS2438_SP_TEMP_LSB] >> 3)) * 31250;
206 0 : sc->sc_voltage_vdd.value =
207 0 : (int)(((u_int16_t)data[DS2438_SP_VOLT_MSB] << 8) |
208 0 : data[DS2438_SP_VOLT_LSB]) * 10000;
209 :
210 0 : sc->sc_voltage_cr.value =
211 0 : (int)(((u_int16_t)data[DS2438_SP_CURRENT_MSB] << 8) |
212 0 : data[DS2438_SP_CURRENT_LSB]) * 244;
213 0 : }
214 :
215 : /* Reconfigure DS2438 to measure VAD */
216 :
217 0 : if (onewire_reset(sc->sc_onewire) != 0)
218 : goto done;
219 :
220 0 : onewire_matchrom(sc->sc_onewire, sc->sc_rom);
221 0 : onewire_write_byte(sc->sc_onewire, DSSBM_CMD_WRITE_SCRATCHPAD);
222 0 : onewire_write_byte(sc->sc_onewire, 0);
223 0 : onewire_write_byte(sc->sc_onewire, 0x7); /* AD = 0 */
224 :
225 0 : if (onewire_reset(sc->sc_onewire) != 0)
226 : goto done;
227 :
228 0 : onewire_matchrom(sc->sc_onewire, sc->sc_rom);
229 0 : onewire_write_byte(sc->sc_onewire, DSSBM_CMD_CONVERT_V);
230 0 : if (onewire_reset(sc->sc_onewire) != 0)
231 : goto done;
232 :
233 0 : onewire_matchrom(sc->sc_onewire, sc->sc_rom);
234 : /* Issue Recall Memory page 00h cmd */
235 0 : onewire_write_byte(sc->sc_onewire, DSSBM_CMD_RECALL_MEMORY);
236 0 : onewire_write_byte(sc->sc_onewire, 0);
237 :
238 0 : if (onewire_reset(sc->sc_onewire) != 0)
239 : goto done;
240 :
241 0 : onewire_matchrom(sc->sc_onewire, sc->sc_rom);
242 0 : onewire_write_byte(sc->sc_onewire, DSSBM_CMD_READ_SCRATCHPAD);
243 0 : onewire_write_byte(sc->sc_onewire, 0);
244 0 : onewire_read_block(sc->sc_onewire, data, 9);
245 0 : if (onewire_crc(data, 8) == data[8]) {
246 0 : sc->sc_voltage_vad.value =
247 0 : (int)(((u_int16_t)data[DS2438_SP_VOLT_MSB] << 8) |
248 0 : data[DS2438_SP_VOLT_LSB]) * 10000;
249 0 : }
250 :
251 : /* Reconfigure back DS2438 to measure VDD (default) */
252 :
253 0 : if (onewire_reset(sc->sc_onewire) != 0)
254 : goto done;
255 :
256 0 : onewire_matchrom(sc->sc_onewire, sc->sc_rom);
257 0 : onewire_write_byte(sc->sc_onewire, DSSBM_CMD_WRITE_SCRATCHPAD);
258 0 : onewire_write_byte(sc->sc_onewire, 0);
259 0 : onewire_write_byte(sc->sc_onewire, 0xf); /* AD = 1 */
260 0 : onewire_reset(sc->sc_onewire);
261 :
262 : done:
263 0 : onewire_unlock(sc->sc_onewire);
264 0 : rw_exit_write(&sc->sc_lock);
265 0 : }
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