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20#include <linux/err.h>
21#include <linux/gpio.h>
22#include <linux/i2c.h>
23#include <linux/init.h>
24#include <linux/interrupt.h>
25#include <linux/kernel.h>
26#include <linux/module.h>
27#include <linux/of.h>
28#include <linux/gpio/consumer.h>
29#include <linux/power_supply.h>
30#include <linux/slab.h>
31
32#include <linux/power/bq24735-charger.h>
33
34#define BQ24735_CHG_OPT 0x12
35#define BQ24735_CHG_OPT_CHARGE_DISABLE (1 << 0)
36#define BQ24735_CHG_OPT_AC_PRESENT (1 << 4)
37#define BQ24735_CHARGE_CURRENT 0x14
38#define BQ24735_CHARGE_CURRENT_MASK 0x1fc0
39#define BQ24735_CHARGE_VOLTAGE 0x15
40#define BQ24735_CHARGE_VOLTAGE_MASK 0x7ff0
41#define BQ24735_INPUT_CURRENT 0x3f
42#define BQ24735_INPUT_CURRENT_MASK 0x1f80
43#define BQ24735_MANUFACTURER_ID 0xfe
44#define BQ24735_DEVICE_ID 0xff
45
46struct bq24735 {
47 struct power_supply *charger;
48 struct power_supply_desc charger_desc;
49 struct i2c_client *client;
50 struct bq24735_platform *pdata;
51 struct mutex lock;
52 struct gpio_desc *status_gpio;
53 struct delayed_work poll;
54 u32 poll_interval;
55 bool charging;
56};
57
58static inline struct bq24735 *to_bq24735(struct power_supply *psy)
59{
60 return power_supply_get_drvdata(psy);
61}
62
63static enum power_supply_property bq24735_charger_properties[] = {
64 POWER_SUPPLY_PROP_STATUS,
65 POWER_SUPPLY_PROP_ONLINE,
66};
67
68static int bq24735_charger_property_is_writeable(struct power_supply *psy,
69 enum power_supply_property psp)
70{
71 switch (psp) {
72 case POWER_SUPPLY_PROP_STATUS:
73 return 1;
74 default:
75 break;
76 }
77
78 return 0;
79}
80
81static inline int bq24735_write_word(struct i2c_client *client, u8 reg,
82 u16 value)
83{
84 return i2c_smbus_write_word_data(client, reg, value);
85}
86
87static inline int bq24735_read_word(struct i2c_client *client, u8 reg)
88{
89 return i2c_smbus_read_word_data(client, reg);
90}
91
92static int bq24735_update_word(struct i2c_client *client, u8 reg,
93 u16 mask, u16 value)
94{
95 unsigned int tmp;
96 int ret;
97
98 ret = bq24735_read_word(client, reg);
99 if (ret < 0)
100 return ret;
101
102 tmp = ret & ~mask;
103 tmp |= value & mask;
104
105 return bq24735_write_word(client, reg, tmp);
106}
107
108static int bq24735_config_charger(struct bq24735 *charger)
109{
110 struct bq24735_platform *pdata = charger->pdata;
111 int ret;
112 u16 value;
113
114 if (pdata->ext_control)
115 return 0;
116
117 if (pdata->charge_current) {
118 value = pdata->charge_current & BQ24735_CHARGE_CURRENT_MASK;
119
120 ret = bq24735_write_word(charger->client,
121 BQ24735_CHARGE_CURRENT, value);
122 if (ret < 0) {
123 dev_err(&charger->client->dev,
124 "Failed to write charger current : %d\n",
125 ret);
126 return ret;
127 }
128 }
129
130 if (pdata->charge_voltage) {
131 value = pdata->charge_voltage & BQ24735_CHARGE_VOLTAGE_MASK;
132
133 ret = bq24735_write_word(charger->client,
134 BQ24735_CHARGE_VOLTAGE, value);
135 if (ret < 0) {
136 dev_err(&charger->client->dev,
137 "Failed to write charger voltage : %d\n",
138 ret);
139 return ret;
140 }
141 }
142
143 if (pdata->input_current) {
144 value = pdata->input_current & BQ24735_INPUT_CURRENT_MASK;
145
146 ret = bq24735_write_word(charger->client,
147 BQ24735_INPUT_CURRENT, value);
148 if (ret < 0) {
149 dev_err(&charger->client->dev,
150 "Failed to write input current : %d\n",
151 ret);
152 return ret;
153 }
154 }
155
156 return 0;
157}
158
159static inline int bq24735_enable_charging(struct bq24735 *charger)
160{
161 int ret;
162
163 if (charger->pdata->ext_control)
164 return 0;
165
166 ret = bq24735_config_charger(charger);
167 if (ret)
168 return ret;
169
170 return bq24735_update_word(charger->client, BQ24735_CHG_OPT,
171 BQ24735_CHG_OPT_CHARGE_DISABLE, 0);
172}
173
174static inline int bq24735_disable_charging(struct bq24735 *charger)
175{
176 if (charger->pdata->ext_control)
177 return 0;
178
179 return bq24735_update_word(charger->client, BQ24735_CHG_OPT,
180 BQ24735_CHG_OPT_CHARGE_DISABLE,
181 BQ24735_CHG_OPT_CHARGE_DISABLE);
182}
183
184static bool bq24735_charger_is_present(struct bq24735 *charger)
185{
186 if (charger->status_gpio) {
187 return !gpiod_get_value_cansleep(charger->status_gpio);
188 } else {
189 int ac = 0;
190
191 ac = bq24735_read_word(charger->client, BQ24735_CHG_OPT);
192 if (ac < 0) {
193 dev_dbg(&charger->client->dev,
194 "Failed to read charger options : %d\n",
195 ac);
196 return false;
197 }
198 return (ac & BQ24735_CHG_OPT_AC_PRESENT) ? true : false;
199 }
200
201 return false;
202}
203
204static int bq24735_charger_is_charging(struct bq24735 *charger)
205{
206 int ret;
207
208 if (!bq24735_charger_is_present(charger))
209 return 0;
210
211 ret = bq24735_read_word(charger->client, BQ24735_CHG_OPT);
212 if (ret < 0)
213 return ret;
214
215 return !(ret & BQ24735_CHG_OPT_CHARGE_DISABLE);
216}
217
218static void bq24735_update(struct bq24735 *charger)
219{
220 mutex_lock(&charger->lock);
221
222 if (charger->charging && bq24735_charger_is_present(charger))
223 bq24735_enable_charging(charger);
224 else
225 bq24735_disable_charging(charger);
226
227 mutex_unlock(&charger->lock);
228
229 power_supply_changed(charger->charger);
230}
231
232static irqreturn_t bq24735_charger_isr(int irq, void *devid)
233{
234 struct power_supply *psy = devid;
235 struct bq24735 *charger = to_bq24735(psy);
236
237 bq24735_update(charger);
238
239 return IRQ_HANDLED;
240}
241
242static void bq24735_poll(struct work_struct *work)
243{
244 struct bq24735 *charger = container_of(work, struct bq24735, poll.work);
245
246 bq24735_update(charger);
247
248 schedule_delayed_work(&charger->poll,
249 msecs_to_jiffies(charger->poll_interval));
250}
251
252static int bq24735_charger_get_property(struct power_supply *psy,
253 enum power_supply_property psp,
254 union power_supply_propval *val)
255{
256 struct bq24735 *charger = to_bq24735(psy);
257
258 switch (psp) {
259 case POWER_SUPPLY_PROP_ONLINE:
260 val->intval = bq24735_charger_is_present(charger) ? 1 : 0;
261 break;
262 case POWER_SUPPLY_PROP_STATUS:
263 switch (bq24735_charger_is_charging(charger)) {
264 case 1:
265 val->intval = POWER_SUPPLY_STATUS_CHARGING;
266 break;
267 case 0:
268 val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
269 break;
270 default:
271 val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
272 break;
273 }
274 break;
275 default:
276 return -EINVAL;
277 }
278
279 return 0;
280}
281
282static int bq24735_charger_set_property(struct power_supply *psy,
283 enum power_supply_property psp,
284 const union power_supply_propval *val)
285{
286 struct bq24735 *charger = to_bq24735(psy);
287 int ret;
288
289 switch (psp) {
290 case POWER_SUPPLY_PROP_STATUS:
291 switch (val->intval) {
292 case POWER_SUPPLY_STATUS_CHARGING:
293 mutex_lock(&charger->lock);
294 charger->charging = true;
295 ret = bq24735_enable_charging(charger);
296 mutex_unlock(&charger->lock);
297 if (ret)
298 return ret;
299 break;
300 case POWER_SUPPLY_STATUS_DISCHARGING:
301 case POWER_SUPPLY_STATUS_NOT_CHARGING:
302 mutex_lock(&charger->lock);
303 charger->charging = false;
304 ret = bq24735_disable_charging(charger);
305 mutex_unlock(&charger->lock);
306 if (ret)
307 return ret;
308 break;
309 default:
310 return -EINVAL;
311 }
312 power_supply_changed(psy);
313 break;
314 default:
315 return -EPERM;
316 }
317
318 return 0;
319}
320
321static struct bq24735_platform *bq24735_parse_dt_data(struct i2c_client *client)
322{
323 struct bq24735_platform *pdata;
324 struct device_node *np = client->dev.of_node;
325 u32 val;
326 int ret;
327
328 pdata = devm_kzalloc(&client->dev, sizeof(*pdata), GFP_KERNEL);
329 if (!pdata) {
330 dev_err(&client->dev,
331 "Memory alloc for bq24735 pdata failed\n");
332 return NULL;
333 }
334
335 ret = of_property_read_u32(np, "ti,charge-current", &val);
336 if (!ret)
337 pdata->charge_current = val;
338
339 ret = of_property_read_u32(np, "ti,charge-voltage", &val);
340 if (!ret)
341 pdata->charge_voltage = val;
342
343 ret = of_property_read_u32(np, "ti,input-current", &val);
344 if (!ret)
345 pdata->input_current = val;
346
347 pdata->ext_control = of_property_read_bool(np, "ti,external-control");
348
349 return pdata;
350}
351
352static int bq24735_charger_probe(struct i2c_client *client,
353 const struct i2c_device_id *id)
354{
355 int ret;
356 struct bq24735 *charger;
357 struct power_supply_desc *supply_desc;
358 struct power_supply_config psy_cfg = {};
359 char *name;
360
361 charger = devm_kzalloc(&client->dev, sizeof(*charger), GFP_KERNEL);
362 if (!charger)
363 return -ENOMEM;
364
365 mutex_init(&charger->lock);
366 charger->charging = true;
367 charger->pdata = client->dev.platform_data;
368
369 if (IS_ENABLED(CONFIG_OF) && !charger->pdata && client->dev.of_node)
370 charger->pdata = bq24735_parse_dt_data(client);
371
372 if (!charger->pdata) {
373 dev_err(&client->dev, "no platform data provided\n");
374 return -EINVAL;
375 }
376
377 name = (char *)charger->pdata->name;
378 if (!name) {
379 name = devm_kasprintf(&client->dev, GFP_KERNEL,
380 "bq24735@%s",
381 dev_name(&client->dev));
382 if (!name) {
383 dev_err(&client->dev, "Failed to alloc device name\n");
384 return -ENOMEM;
385 }
386 }
387
388 charger->client = client;
389
390 supply_desc = &charger->charger_desc;
391
392 supply_desc->name = name;
393 supply_desc->type = POWER_SUPPLY_TYPE_MAINS;
394 supply_desc->properties = bq24735_charger_properties;
395 supply_desc->num_properties = ARRAY_SIZE(bq24735_charger_properties);
396 supply_desc->get_property = bq24735_charger_get_property;
397 supply_desc->set_property = bq24735_charger_set_property;
398 supply_desc->property_is_writeable =
399 bq24735_charger_property_is_writeable;
400
401 psy_cfg.supplied_to = charger->pdata->supplied_to;
402 psy_cfg.num_supplicants = charger->pdata->num_supplicants;
403 psy_cfg.of_node = client->dev.of_node;
404 psy_cfg.drv_data = charger;
405
406 i2c_set_clientdata(client, charger);
407
408 charger->status_gpio = devm_gpiod_get_optional(&client->dev,
409 "ti,ac-detect",
410 GPIOD_IN);
411 if (IS_ERR(charger->status_gpio)) {
412 ret = PTR_ERR(charger->status_gpio);
413 dev_err(&client->dev, "Getting gpio failed: %d\n", ret);
414 return ret;
415 }
416
417 if (bq24735_charger_is_present(charger)) {
418 ret = bq24735_read_word(client, BQ24735_MANUFACTURER_ID);
419 if (ret < 0) {
420 dev_err(&client->dev, "Failed to read manufacturer id : %d\n",
421 ret);
422 return ret;
423 } else if (ret != 0x0040) {
424 dev_err(&client->dev,
425 "manufacturer id mismatch. 0x0040 != 0x%04x\n", ret);
426 return -ENODEV;
427 }
428
429 ret = bq24735_read_word(client, BQ24735_DEVICE_ID);
430 if (ret < 0) {
431 dev_err(&client->dev, "Failed to read device id : %d\n", ret);
432 return ret;
433 } else if (ret != 0x000B) {
434 dev_err(&client->dev,
435 "device id mismatch. 0x000b != 0x%04x\n", ret);
436 return -ENODEV;
437 }
438
439 ret = bq24735_enable_charging(charger);
440 if (ret < 0) {
441 dev_err(&client->dev, "Failed to enable charging\n");
442 return ret;
443 }
444 }
445
446 charger->charger = devm_power_supply_register(&client->dev, supply_desc,
447 &psy_cfg);
448 if (IS_ERR(charger->charger)) {
449 ret = PTR_ERR(charger->charger);
450 dev_err(&client->dev, "Failed to register power supply: %d\n",
451 ret);
452 return ret;
453 }
454
455 if (client->irq) {
456 ret = devm_request_threaded_irq(&client->dev, client->irq,
457 NULL, bq24735_charger_isr,
458 IRQF_TRIGGER_RISING |
459 IRQF_TRIGGER_FALLING |
460 IRQF_ONESHOT,
461 supply_desc->name,
462 charger->charger);
463 if (ret) {
464 dev_err(&client->dev,
465 "Unable to register IRQ %d err %d\n",
466 client->irq, ret);
467 return ret;
468 }
469 } else {
470 ret = device_property_read_u32(&client->dev, "poll-interval",
471 &charger->poll_interval);
472 if (ret)
473 return 0;
474 if (!charger->poll_interval)
475 return 0;
476
477 INIT_DELAYED_WORK(&charger->poll, bq24735_poll);
478 schedule_delayed_work(&charger->poll,
479 msecs_to_jiffies(charger->poll_interval));
480 }
481
482 return 0;
483}
484
485static int bq24735_charger_remove(struct i2c_client *client)
486{
487 struct bq24735 *charger = i2c_get_clientdata(client);
488
489 if (charger->poll_interval)
490 cancel_delayed_work_sync(&charger->poll);
491
492 return 0;
493}
494
495static const struct i2c_device_id bq24735_charger_id[] = {
496 { "bq24735-charger", 0 },
497 {}
498};
499MODULE_DEVICE_TABLE(i2c, bq24735_charger_id);
500
501static const struct of_device_id bq24735_match_ids[] = {
502 { .compatible = "ti,bq24735", },
503 { }
504};
505MODULE_DEVICE_TABLE(of, bq24735_match_ids);
506
507static struct i2c_driver bq24735_charger_driver = {
508 .driver = {
509 .name = "bq24735-charger",
510 .of_match_table = bq24735_match_ids,
511 },
512 .probe = bq24735_charger_probe,
513 .remove = bq24735_charger_remove,
514 .id_table = bq24735_charger_id,
515};
516
517module_i2c_driver(bq24735_charger_driver);
518
519MODULE_DESCRIPTION("bq24735 battery charging driver");
520MODULE_AUTHOR("Darbha Sriharsha <dsriharsha@nvidia.com>");
521MODULE_LICENSE("GPL v2");
522