1 /* $OpenBSD: owsbm.c,v 1.11 2022/04/06 18:59:29 naddy 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 const 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
owsbm_match(struct device * parent,void * match,void * aux)99 owsbm_match(struct device *parent, void *match, void *aux)
100 {
101 return (onewire_matchbyfam(aux, owsbm_fams, nitems(owsbm_fams)));
102 }
103
104 void
owsbm_attach(struct device * parent,struct device * self,void * aux)105 owsbm_attach(struct device *parent, struct device *self, void *aux)
106 {
107 struct owsbm_softc *sc = (struct owsbm_softc *)self;
108 struct onewire_attach_args *oa = aux;
109
110 sc->sc_onewire = oa->oa_onewire;
111 sc->sc_rom = oa->oa_rom;
112
113 /* Initialize temp sensor */
114 strlcpy(sc->sc_sensordev.xname, sc->sc_dev.dv_xname,
115 sizeof(sc->sc_sensordev.xname));
116 sc->sc_temp.type = SENSOR_TEMP;
117 snprintf(sc->sc_temp.desc, sizeof(sc->sc_temp.desc), "sn %012llx",
118 ONEWIRE_ROM_SN(oa->oa_rom));
119 sensor_attach(&sc->sc_sensordev, &sc->sc_temp);
120
121 /* Initialize voltage sensor */
122 sc->sc_voltage_vdd.type = SENSOR_VOLTS_DC;
123 strlcpy(sc->sc_voltage_vdd.desc, "VDD", sizeof(sc->sc_voltage_vdd.desc));
124 sensor_attach(&sc->sc_sensordev, &sc->sc_voltage_vdd);
125
126 /* Initialize voltage sensor */
127 sc->sc_voltage_vad.type = SENSOR_VOLTS_DC;
128 strlcpy(sc->sc_voltage_vad.desc, "VAD", sizeof(sc->sc_voltage_vad.desc));
129 sensor_attach(&sc->sc_sensordev, &sc->sc_voltage_vad);
130
131 /* Initialize the current sensor */
132 sc->sc_voltage_cr.type = SENSOR_VOLTS_DC;
133 strlcpy(sc->sc_voltage_cr.desc, "CR", sizeof(sc->sc_voltage_cr.desc));
134 sensor_attach(&sc->sc_sensordev, &sc->sc_voltage_cr);
135
136 sc->sc_sensortask = sensor_task_register(sc, owsbm_update, 10);
137 if (sc->sc_sensortask == NULL) {
138 printf(": unable to register update task\n");
139 return;
140 }
141
142 sensordev_install(&sc->sc_sensordev);
143
144 rw_init(&sc->sc_lock, sc->sc_dev.dv_xname);
145 printf("\n");
146 }
147
148 int
owsbm_detach(struct device * self,int flags)149 owsbm_detach(struct device *self, int flags)
150 {
151 struct owsbm_softc *sc = (struct owsbm_softc *)self;
152
153 rw_enter_write(&sc->sc_lock);
154 sensordev_deinstall(&sc->sc_sensordev);
155 if (sc->sc_sensortask != NULL)
156 sensor_task_unregister(sc->sc_sensortask);
157 rw_exit_write(&sc->sc_lock);
158
159 return (0);
160 }
161
162 int
owsbm_activate(struct device * self,int act)163 owsbm_activate(struct device *self, int act)
164 {
165 return (0);
166 }
167
168 void
owsbm_update(void * arg)169 owsbm_update(void *arg)
170 {
171 struct owsbm_softc *sc = arg;
172 u_int8_t data[9];
173
174 rw_enter_write(&sc->sc_lock);
175 onewire_lock(sc->sc_onewire, 0);
176 if (onewire_reset(sc->sc_onewire) != 0)
177 goto done;
178
179 onewire_matchrom(sc->sc_onewire, sc->sc_rom);
180 onewire_write_byte(sc->sc_onewire, DSSBM_CMD_CONVERT_T);
181 if (onewire_reset(sc->sc_onewire) != 0)
182 goto done;
183
184 onewire_matchrom(sc->sc_onewire, sc->sc_rom);
185 onewire_write_byte(sc->sc_onewire, DSSBM_CMD_CONVERT_V);
186 if (onewire_reset(sc->sc_onewire) != 0)
187 goto done;
188
189 onewire_matchrom(sc->sc_onewire, sc->sc_rom);
190 /* Issue Recall Memory page 00h cmd */
191 onewire_write_byte(sc->sc_onewire, DSSBM_CMD_RECALL_MEMORY);
192 onewire_write_byte(sc->sc_onewire, 0);
193
194 if (onewire_reset(sc->sc_onewire) != 0)
195 goto done;
196
197 onewire_matchrom(sc->sc_onewire, sc->sc_rom);
198 /* Read page 0 of Memory Map from Scratchpad */
199 onewire_write_byte(sc->sc_onewire, DSSBM_CMD_READ_SCRATCHPAD);
200 onewire_write_byte(sc->sc_onewire, 0);
201 onewire_read_block(sc->sc_onewire, data, 9);
202 if (onewire_crc(data, 8) == data[DS2438_SP_CRC]) {
203 sc->sc_temp.value = 273150000 +
204 (int)(((u_int16_t)data[DS2438_SP_TEMP_MSB] << 5) |
205 ((u_int16_t)data[DS2438_SP_TEMP_LSB] >> 3)) * 31250;
206 sc->sc_voltage_vdd.value =
207 (int)(((u_int16_t)data[DS2438_SP_VOLT_MSB] << 8) |
208 data[DS2438_SP_VOLT_LSB]) * 10000;
209
210 sc->sc_voltage_cr.value =
211 (int)(((u_int16_t)data[DS2438_SP_CURRENT_MSB] << 8) |
212 data[DS2438_SP_CURRENT_LSB]) * 244;
213 }
214
215 /* Reconfigure DS2438 to measure VAD */
216
217 if (onewire_reset(sc->sc_onewire) != 0)
218 goto done;
219
220 onewire_matchrom(sc->sc_onewire, sc->sc_rom);
221 onewire_write_byte(sc->sc_onewire, DSSBM_CMD_WRITE_SCRATCHPAD);
222 onewire_write_byte(sc->sc_onewire, 0);
223 onewire_write_byte(sc->sc_onewire, 0x7); /* AD = 0 */
224
225 if (onewire_reset(sc->sc_onewire) != 0)
226 goto done;
227
228 onewire_matchrom(sc->sc_onewire, sc->sc_rom);
229 onewire_write_byte(sc->sc_onewire, DSSBM_CMD_CONVERT_V);
230 if (onewire_reset(sc->sc_onewire) != 0)
231 goto done;
232
233 onewire_matchrom(sc->sc_onewire, sc->sc_rom);
234 /* Issue Recall Memory page 00h cmd */
235 onewire_write_byte(sc->sc_onewire, DSSBM_CMD_RECALL_MEMORY);
236 onewire_write_byte(sc->sc_onewire, 0);
237
238 if (onewire_reset(sc->sc_onewire) != 0)
239 goto done;
240
241 onewire_matchrom(sc->sc_onewire, sc->sc_rom);
242 onewire_write_byte(sc->sc_onewire, DSSBM_CMD_READ_SCRATCHPAD);
243 onewire_write_byte(sc->sc_onewire, 0);
244 onewire_read_block(sc->sc_onewire, data, 9);
245 if (onewire_crc(data, 8) == data[8]) {
246 sc->sc_voltage_vad.value =
247 (int)(((u_int16_t)data[DS2438_SP_VOLT_MSB] << 8) |
248 data[DS2438_SP_VOLT_LSB]) * 10000;
249 }
250
251 /* Reconfigure back DS2438 to measure VDD (default) */
252
253 if (onewire_reset(sc->sc_onewire) != 0)
254 goto done;
255
256 onewire_matchrom(sc->sc_onewire, sc->sc_rom);
257 onewire_write_byte(sc->sc_onewire, DSSBM_CMD_WRITE_SCRATCHPAD);
258 onewire_write_byte(sc->sc_onewire, 0);
259 onewire_write_byte(sc->sc_onewire, 0xf); /* AD = 1 */
260 onewire_reset(sc->sc_onewire);
261
262 done:
263 onewire_unlock(sc->sc_onewire);
264 rw_exit_write(&sc->sc_lock);
265 }
266