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fe0e3153 AV |
1 | /* |
2 | * Driver for batteries with DS2760 chips inside. | |
3 | * | |
4 | * Copyright © 2007 Anton Vorontsov | |
5 | * 2004-2007 Matt Reimer | |
6 | * 2004 Szabolcs Gyurko | |
7 | * | |
8 | * Use consistent with the GNU GPL is permitted, | |
9 | * provided that this copyright notice is | |
10 | * preserved in its entirety in all copies and derived works. | |
11 | * | |
12 | * Author: Anton Vorontsov <[email protected]> | |
13 | * February 2007 | |
14 | * | |
15 | * Matt Reimer <[email protected]> | |
16 | * April 2004, 2005, 2007 | |
17 | * | |
18 | * Szabolcs Gyurko <[email protected]> | |
19 | * September 2004 | |
20 | */ | |
21 | ||
22 | #include <linux/module.h> | |
23 | #include <linux/param.h> | |
24 | #include <linux/jiffies.h> | |
25 | #include <linux/workqueue.h> | |
26 | #include <linux/pm.h> | |
27 | #include <linux/platform_device.h> | |
28 | #include <linux/power_supply.h> | |
29 | ||
30 | #include "../w1/w1.h" | |
31 | #include "../w1/slaves/w1_ds2760.h" | |
32 | ||
33 | struct ds2760_device_info { | |
34 | struct device *dev; | |
35 | ||
36 | /* DS2760 data, valid after calling ds2760_battery_read_status() */ | |
37 | unsigned long update_time; /* jiffies when data read */ | |
38 | char raw[DS2760_DATA_SIZE]; /* raw DS2760 data */ | |
39 | int voltage_raw; /* units of 4.88 mV */ | |
40 | int voltage_uV; /* units of µV */ | |
41 | int current_raw; /* units of 0.625 mA */ | |
42 | int current_uA; /* units of µA */ | |
43 | int accum_current_raw; /* units of 0.25 mAh */ | |
44 | int accum_current_uAh; /* units of µAh */ | |
45 | int temp_raw; /* units of 0.125 °C */ | |
46 | int temp_C; /* units of 0.1 °C */ | |
47 | int rated_capacity; /* units of µAh */ | |
48 | int rem_capacity; /* percentage */ | |
49 | int full_active_uAh; /* units of µAh */ | |
50 | int empty_uAh; /* units of µAh */ | |
51 | int life_sec; /* units of seconds */ | |
52 | int charge_status; /* POWER_SUPPLY_STATUS_* */ | |
53 | ||
54 | int full_counter; | |
55 | struct power_supply bat; | |
56 | struct device *w1_dev; | |
57 | struct workqueue_struct *monitor_wqueue; | |
58 | struct delayed_work monitor_work; | |
59 | }; | |
60 | ||
61 | static unsigned int cache_time = 1000; | |
62 | module_param(cache_time, uint, 0644); | |
63 | MODULE_PARM_DESC(cache_time, "cache time in milliseconds"); | |
64 | ||
65 | /* Some batteries have their rated capacity stored a N * 10 mAh, while | |
66 | * others use an index into this table. */ | |
67 | static int rated_capacities[] = { | |
68 | 0, | |
69 | 920, /* Samsung */ | |
70 | 920, /* BYD */ | |
71 | 920, /* Lishen */ | |
72 | 920, /* NEC */ | |
73 | 1440, /* Samsung */ | |
74 | 1440, /* BYD */ | |
75 | 1440, /* Lishen */ | |
76 | 1440, /* NEC */ | |
77 | 2880, /* Samsung */ | |
78 | 2880, /* BYD */ | |
79 | 2880, /* Lishen */ | |
80 | 2880 /* NEC */ | |
81 | }; | |
82 | ||
83 | /* array is level at temps 0°C, 10°C, 20°C, 30°C, 40°C | |
84 | * temp is in Celsius */ | |
85 | static int battery_interpolate(int array[], int temp) | |
86 | { | |
87 | int index, dt; | |
88 | ||
89 | if (temp <= 0) | |
90 | return array[0]; | |
91 | if (temp >= 40) | |
92 | return array[4]; | |
93 | ||
94 | index = temp / 10; | |
95 | dt = temp % 10; | |
96 | ||
97 | return array[index] + (((array[index + 1] - array[index]) * dt) / 10); | |
98 | } | |
99 | ||
100 | static int ds2760_battery_read_status(struct ds2760_device_info *di) | |
101 | { | |
102 | int ret, i, start, count, scale[5]; | |
103 | ||
104 | if (di->update_time && time_before(jiffies, di->update_time + | |
105 | msecs_to_jiffies(cache_time))) | |
106 | return 0; | |
107 | ||
108 | /* The first time we read the entire contents of SRAM/EEPROM, | |
109 | * but after that we just read the interesting bits that change. */ | |
110 | if (di->update_time == 0) { | |
111 | start = 0; | |
112 | count = DS2760_DATA_SIZE; | |
113 | } else { | |
114 | start = DS2760_VOLTAGE_MSB; | |
115 | count = DS2760_TEMP_LSB - start + 1; | |
116 | } | |
117 | ||
118 | ret = w1_ds2760_read(di->w1_dev, di->raw + start, start, count); | |
119 | if (ret != count) { | |
120 | dev_warn(di->dev, "call to w1_ds2760_read failed (0x%p)\n", | |
121 | di->w1_dev); | |
122 | return 1; | |
123 | } | |
124 | ||
125 | di->update_time = jiffies; | |
126 | ||
127 | /* DS2760 reports voltage in units of 4.88mV, but the battery class | |
128 | * reports in units of uV, so convert by multiplying by 4880. */ | |
129 | di->voltage_raw = (di->raw[DS2760_VOLTAGE_MSB] << 3) | | |
130 | (di->raw[DS2760_VOLTAGE_LSB] >> 5); | |
131 | di->voltage_uV = di->voltage_raw * 4880; | |
132 | ||
133 | /* DS2760 reports current in signed units of 0.625mA, but the battery | |
134 | * class reports in units of µA, so convert by multiplying by 625. */ | |
135 | di->current_raw = | |
136 | (((signed char)di->raw[DS2760_CURRENT_MSB]) << 5) | | |
137 | (di->raw[DS2760_CURRENT_LSB] >> 3); | |
138 | di->current_uA = di->current_raw * 625; | |
139 | ||
140 | /* DS2760 reports accumulated current in signed units of 0.25mAh. */ | |
141 | di->accum_current_raw = | |
142 | (((signed char)di->raw[DS2760_CURRENT_ACCUM_MSB]) << 8) | | |
143 | di->raw[DS2760_CURRENT_ACCUM_LSB]; | |
144 | di->accum_current_uAh = di->accum_current_raw * 250; | |
145 | ||
146 | /* DS2760 reports temperature in signed units of 0.125°C, but the | |
147 | * battery class reports in units of 1/10 °C, so we convert by | |
148 | * multiplying by .125 * 10 = 1.25. */ | |
149 | di->temp_raw = (((signed char)di->raw[DS2760_TEMP_MSB]) << 3) | | |
150 | (di->raw[DS2760_TEMP_LSB] >> 5); | |
151 | di->temp_C = di->temp_raw + (di->temp_raw / 4); | |
152 | ||
153 | /* At least some battery monitors (e.g. HP iPAQ) store the battery's | |
154 | * maximum rated capacity. */ | |
155 | if (di->raw[DS2760_RATED_CAPACITY] < ARRAY_SIZE(rated_capacities)) | |
156 | di->rated_capacity = rated_capacities[ | |
157 | (unsigned int)di->raw[DS2760_RATED_CAPACITY]]; | |
158 | else | |
159 | di->rated_capacity = di->raw[DS2760_RATED_CAPACITY] * 10; | |
160 | ||
161 | di->rated_capacity *= 1000; /* convert to µAh */ | |
162 | ||
163 | /* Calculate the full level at the present temperature. */ | |
164 | di->full_active_uAh = di->raw[DS2760_ACTIVE_FULL] << 8 | | |
165 | di->raw[DS2760_ACTIVE_FULL + 1]; | |
166 | ||
167 | scale[0] = di->raw[DS2760_ACTIVE_FULL] << 8 | | |
168 | di->raw[DS2760_ACTIVE_FULL + 1]; | |
169 | for (i = 1; i < 5; i++) | |
170 | scale[i] = scale[i - 1] + di->raw[DS2760_ACTIVE_FULL + 2 + i]; | |
171 | ||
172 | di->full_active_uAh = battery_interpolate(scale, di->temp_C / 10); | |
173 | di->full_active_uAh *= 1000; /* convert to µAh */ | |
174 | ||
175 | /* Calculate the empty level at the present temperature. */ | |
176 | scale[4] = di->raw[DS2760_ACTIVE_EMPTY + 4]; | |
177 | for (i = 3; i >= 0; i--) | |
178 | scale[i] = scale[i + 1] + di->raw[DS2760_ACTIVE_EMPTY + i]; | |
179 | ||
180 | di->empty_uAh = battery_interpolate(scale, di->temp_C / 10); | |
181 | di->empty_uAh *= 1000; /* convert to µAh */ | |
182 | ||
183 | /* From Maxim Application Note 131: remaining capacity = | |
184 | * ((ICA - Empty Value) / (Full Value - Empty Value)) x 100% */ | |
185 | di->rem_capacity = ((di->accum_current_uAh - di->empty_uAh) * 100L) / | |
186 | (di->full_active_uAh - di->empty_uAh); | |
187 | ||
188 | if (di->rem_capacity < 0) | |
189 | di->rem_capacity = 0; | |
190 | if (di->rem_capacity > 100) | |
191 | di->rem_capacity = 100; | |
192 | ||
193 | if (di->current_uA) | |
194 | di->life_sec = -((di->accum_current_uAh - di->empty_uAh) * | |
195 | 3600L) / di->current_uA; | |
196 | else | |
197 | di->life_sec = 0; | |
198 | ||
199 | return 0; | |
200 | } | |
201 | ||
202 | static void ds2760_battery_update_status(struct ds2760_device_info *di) | |
203 | { | |
204 | int old_charge_status = di->charge_status; | |
205 | ||
206 | ds2760_battery_read_status(di); | |
207 | ||
208 | if (di->charge_status == POWER_SUPPLY_STATUS_UNKNOWN) | |
209 | di->full_counter = 0; | |
210 | ||
211 | if (power_supply_am_i_supplied(&di->bat)) { | |
212 | if (di->current_uA > 10000) { | |
213 | di->charge_status = POWER_SUPPLY_STATUS_CHARGING; | |
214 | di->full_counter = 0; | |
215 | } else if (di->current_uA < -5000) { | |
216 | if (di->charge_status != POWER_SUPPLY_STATUS_NOT_CHARGING) | |
217 | dev_notice(di->dev, "not enough power to " | |
218 | "charge\n"); | |
219 | di->charge_status = POWER_SUPPLY_STATUS_NOT_CHARGING; | |
220 | di->full_counter = 0; | |
221 | } else if (di->current_uA < 10000 && | |
222 | di->charge_status != POWER_SUPPLY_STATUS_FULL) { | |
223 | ||
224 | /* Don't consider the battery to be full unless | |
225 | * we've seen the current < 10 mA at least two | |
226 | * consecutive times. */ | |
227 | ||
228 | di->full_counter++; | |
229 | ||
230 | if (di->full_counter < 2) { | |
231 | di->charge_status = POWER_SUPPLY_STATUS_CHARGING; | |
232 | } else { | |
233 | unsigned char acr[2]; | |
234 | int acr_val; | |
235 | ||
236 | /* acr is in units of 0.25 mAh */ | |
237 | acr_val = di->full_active_uAh * 4L / 1000; | |
238 | ||
239 | acr[0] = acr_val >> 8; | |
240 | acr[1] = acr_val & 0xff; | |
241 | ||
242 | if (w1_ds2760_write(di->w1_dev, acr, | |
243 | DS2760_CURRENT_ACCUM_MSB, 2) < 2) | |
244 | dev_warn(di->dev, | |
245 | "ACR reset failed\n"); | |
246 | ||
247 | di->charge_status = POWER_SUPPLY_STATUS_FULL; | |
248 | } | |
249 | } | |
250 | } else { | |
251 | di->charge_status = POWER_SUPPLY_STATUS_DISCHARGING; | |
252 | di->full_counter = 0; | |
253 | } | |
254 | ||
255 | if (di->charge_status != old_charge_status) | |
256 | power_supply_changed(&di->bat); | |
fe0e3153 AV |
257 | } |
258 | ||
259 | static void ds2760_battery_work(struct work_struct *work) | |
260 | { | |
261 | struct ds2760_device_info *di = container_of(work, | |
262 | struct ds2760_device_info, monitor_work.work); | |
263 | const int interval = HZ * 60; | |
264 | ||
0cddc0a9 | 265 | dev_dbg(di->dev, "%s\n", __func__); |
fe0e3153 AV |
266 | |
267 | ds2760_battery_update_status(di); | |
268 | queue_delayed_work(di->monitor_wqueue, &di->monitor_work, interval); | |
fe0e3153 AV |
269 | } |
270 | ||
271 | #define to_ds2760_device_info(x) container_of((x), struct ds2760_device_info, \ | |
272 | bat); | |
273 | ||
274 | static void ds2760_battery_external_power_changed(struct power_supply *psy) | |
275 | { | |
276 | struct ds2760_device_info *di = to_ds2760_device_info(psy); | |
277 | ||
0cddc0a9 | 278 | dev_dbg(di->dev, "%s\n", __func__); |
fe0e3153 AV |
279 | |
280 | cancel_delayed_work(&di->monitor_work); | |
281 | queue_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ/10); | |
fe0e3153 AV |
282 | } |
283 | ||
284 | static int ds2760_battery_get_property(struct power_supply *psy, | |
285 | enum power_supply_property psp, | |
286 | union power_supply_propval *val) | |
287 | { | |
288 | struct ds2760_device_info *di = to_ds2760_device_info(psy); | |
289 | ||
290 | switch (psp) { | |
291 | case POWER_SUPPLY_PROP_STATUS: | |
292 | val->intval = di->charge_status; | |
293 | return 0; | |
294 | default: | |
295 | break; | |
296 | } | |
297 | ||
298 | ds2760_battery_read_status(di); | |
299 | ||
300 | switch (psp) { | |
301 | case POWER_SUPPLY_PROP_VOLTAGE_NOW: | |
302 | val->intval = di->voltage_uV; | |
303 | break; | |
304 | case POWER_SUPPLY_PROP_CURRENT_NOW: | |
305 | val->intval = di->current_uA; | |
306 | break; | |
307 | case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN: | |
308 | val->intval = di->rated_capacity; | |
309 | break; | |
310 | case POWER_SUPPLY_PROP_CHARGE_FULL: | |
311 | val->intval = di->full_active_uAh; | |
312 | break; | |
313 | case POWER_SUPPLY_PROP_CHARGE_EMPTY: | |
314 | val->intval = di->empty_uAh; | |
315 | break; | |
316 | case POWER_SUPPLY_PROP_CHARGE_NOW: | |
317 | val->intval = di->accum_current_uAh; | |
318 | break; | |
319 | case POWER_SUPPLY_PROP_TEMP: | |
320 | val->intval = di->temp_C; | |
321 | break; | |
322 | default: | |
323 | return -EINVAL; | |
324 | } | |
325 | ||
326 | return 0; | |
327 | } | |
328 | ||
329 | static enum power_supply_property ds2760_battery_props[] = { | |
330 | POWER_SUPPLY_PROP_STATUS, | |
331 | POWER_SUPPLY_PROP_VOLTAGE_NOW, | |
332 | POWER_SUPPLY_PROP_CURRENT_NOW, | |
333 | POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN, | |
334 | POWER_SUPPLY_PROP_CHARGE_FULL, | |
335 | POWER_SUPPLY_PROP_CHARGE_EMPTY, | |
336 | POWER_SUPPLY_PROP_CHARGE_NOW, | |
337 | POWER_SUPPLY_PROP_TEMP, | |
338 | }; | |
339 | ||
340 | static int ds2760_battery_probe(struct platform_device *pdev) | |
341 | { | |
342 | int retval = 0; | |
343 | struct ds2760_device_info *di; | |
344 | struct ds2760_platform_data *pdata; | |
345 | ||
346 | di = kzalloc(sizeof(*di), GFP_KERNEL); | |
347 | if (!di) { | |
348 | retval = -ENOMEM; | |
349 | goto di_alloc_failed; | |
350 | } | |
351 | ||
352 | platform_set_drvdata(pdev, di); | |
353 | ||
354 | pdata = pdev->dev.platform_data; | |
355 | di->dev = &pdev->dev; | |
356 | di->w1_dev = pdev->dev.parent; | |
357 | di->bat.name = pdev->dev.bus_id; | |
358 | di->bat.type = POWER_SUPPLY_TYPE_BATTERY; | |
359 | di->bat.properties = ds2760_battery_props; | |
360 | di->bat.num_properties = ARRAY_SIZE(ds2760_battery_props); | |
361 | di->bat.get_property = ds2760_battery_get_property; | |
362 | di->bat.external_power_changed = | |
363 | ds2760_battery_external_power_changed; | |
364 | ||
365 | di->charge_status = POWER_SUPPLY_STATUS_UNKNOWN; | |
366 | ||
367 | retval = power_supply_register(&pdev->dev, &di->bat); | |
368 | if (retval) { | |
898eb71c | 369 | dev_err(di->dev, "failed to register battery\n"); |
fe0e3153 AV |
370 | goto batt_failed; |
371 | } | |
372 | ||
373 | INIT_DELAYED_WORK(&di->monitor_work, ds2760_battery_work); | |
374 | di->monitor_wqueue = create_singlethread_workqueue(pdev->dev.bus_id); | |
375 | if (!di->monitor_wqueue) { | |
376 | retval = -ESRCH; | |
377 | goto workqueue_failed; | |
378 | } | |
379 | queue_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ * 1); | |
380 | ||
381 | goto success; | |
382 | ||
383 | workqueue_failed: | |
384 | power_supply_unregister(&di->bat); | |
385 | batt_failed: | |
386 | kfree(di); | |
387 | di_alloc_failed: | |
388 | success: | |
389 | return retval; | |
390 | } | |
391 | ||
392 | static int ds2760_battery_remove(struct platform_device *pdev) | |
393 | { | |
394 | struct ds2760_device_info *di = platform_get_drvdata(pdev); | |
395 | ||
396 | cancel_rearming_delayed_workqueue(di->monitor_wqueue, | |
397 | &di->monitor_work); | |
398 | destroy_workqueue(di->monitor_wqueue); | |
399 | power_supply_unregister(&di->bat); | |
400 | ||
401 | return 0; | |
402 | } | |
403 | ||
404 | #ifdef CONFIG_PM | |
405 | ||
406 | static int ds2760_battery_suspend(struct platform_device *pdev, | |
407 | pm_message_t state) | |
408 | { | |
409 | struct ds2760_device_info *di = platform_get_drvdata(pdev); | |
410 | ||
411 | di->charge_status = POWER_SUPPLY_STATUS_UNKNOWN; | |
412 | ||
413 | return 0; | |
414 | } | |
415 | ||
416 | static int ds2760_battery_resume(struct platform_device *pdev) | |
417 | { | |
418 | struct ds2760_device_info *di = platform_get_drvdata(pdev); | |
419 | ||
420 | di->charge_status = POWER_SUPPLY_STATUS_UNKNOWN; | |
421 | power_supply_changed(&di->bat); | |
422 | ||
423 | cancel_delayed_work(&di->monitor_work); | |
424 | queue_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ); | |
425 | ||
426 | return 0; | |
427 | } | |
428 | ||
429 | #else | |
430 | ||
431 | #define ds2760_battery_suspend NULL | |
432 | #define ds2760_battery_resume NULL | |
433 | ||
434 | #endif /* CONFIG_PM */ | |
435 | ||
436 | static struct platform_driver ds2760_battery_driver = { | |
437 | .driver = { | |
438 | .name = "ds2760-battery", | |
439 | }, | |
440 | .probe = ds2760_battery_probe, | |
441 | .remove = ds2760_battery_remove, | |
442 | .suspend = ds2760_battery_suspend, | |
443 | .resume = ds2760_battery_resume, | |
444 | }; | |
445 | ||
446 | static int __init ds2760_battery_init(void) | |
447 | { | |
448 | return platform_driver_register(&ds2760_battery_driver); | |
449 | } | |
450 | ||
451 | static void __exit ds2760_battery_exit(void) | |
452 | { | |
453 | platform_driver_unregister(&ds2760_battery_driver); | |
fe0e3153 AV |
454 | } |
455 | ||
456 | module_init(ds2760_battery_init); | |
457 | module_exit(ds2760_battery_exit); | |
458 | ||
459 | MODULE_LICENSE("GPL"); | |
460 | MODULE_AUTHOR("Szabolcs Gyurko <[email protected]>, " | |
461 | "Matt Reimer <[email protected]>, " | |
462 | "Anton Vorontsov <[email protected]>"); | |
463 | MODULE_DESCRIPTION("ds2760 battery driver"); |