1 /*
2 * TWL4030/TPS65950 BCI (Battery Charger Interface) driver
3 *
4 * Copyright (C) 2010 Gražvydas Ignotas <notasas@gmail.com>
5 *
6 * based on twl4030_bci_battery.c by TI
7 * Copyright (C) 2008 Texas Instruments, Inc.
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 */
14
15 #include <linux/init.h>
16 #include <linux/module.h>
17 #include <linux/slab.h>
18 #include <linux/platform_device.h>
19 #include <linux/interrupt.h>
20 #include <linux/i2c/twl.h>
21 #include <linux/power_supply.h>
22 #include <linux/notifier.h>
23 #include <linux/usb/otg.h>
24
25 #define TWL4030_BCIMSTATEC 0x02
26 #define TWL4030_BCIICHG 0x08
27 #define TWL4030_BCIVAC 0x0a
28 #define TWL4030_BCIVBUS 0x0c
29 #define TWL4030_BCIMFSTS4 0x10
30 #define TWL4030_BCICTL1 0x23
31
32 #define TWL4030_BCIAUTOWEN BIT(5)
33 #define TWL4030_CONFIG_DONE BIT(4)
34 #define TWL4030_BCIAUTOUSB BIT(1)
35 #define TWL4030_BCIAUTOAC BIT(0)
36 #define TWL4030_CGAIN BIT(5)
37 #define TWL4030_USBFASTMCHG BIT(2)
38 #define TWL4030_STS_VBUS BIT(7)
39 #define TWL4030_STS_USB_ID BIT(2)
40
41 /* BCI interrupts */
42 #define TWL4030_WOVF BIT(0) /* Watchdog overflow */
43 #define TWL4030_TMOVF BIT(1) /* Timer overflow */
44 #define TWL4030_ICHGHIGH BIT(2) /* Battery charge current high */
45 #define TWL4030_ICHGLOW BIT(3) /* Battery cc. low / FSM state change */
46 #define TWL4030_ICHGEOC BIT(4) /* Battery current end-of-charge */
47 #define TWL4030_TBATOR2 BIT(5) /* Battery temperature out of range 2 */
48 #define TWL4030_TBATOR1 BIT(6) /* Battery temperature out of range 1 */
49 #define TWL4030_BATSTS BIT(7) /* Battery status */
50
51 #define TWL4030_VBATLVL BIT(0) /* VBAT level */
52 #define TWL4030_VBATOV BIT(1) /* VBAT overvoltage */
53 #define TWL4030_VBUSOV BIT(2) /* VBUS overvoltage */
54 #define TWL4030_ACCHGOV BIT(3) /* Ac charger overvoltage */
55
56 #define TWL4030_MSTATEC_USB BIT(4)
57 #define TWL4030_MSTATEC_AC BIT(5)
58 #define TWL4030_MSTATEC_MASK 0x0f
59 #define TWL4030_MSTATEC_QUICK1 0x02
60 #define TWL4030_MSTATEC_QUICK7 0x07
61 #define TWL4030_MSTATEC_COMPLETE1 0x0b
62 #define TWL4030_MSTATEC_COMPLETE4 0x0e
63
64 static bool allow_usb;
65 module_param(allow_usb, bool, 0644);
66 MODULE_PARM_DESC(allow_usb, "Allow USB charge drawing default current");
67
68 struct twl4030_bci {
69 struct device *dev;
70 struct power_supply ac;
71 struct power_supply usb;
72 struct otg_transceiver *transceiver;
73 struct notifier_block otg_nb;
74 struct work_struct work;
75 int irq_chg;
76 int irq_bci;
77
78 unsigned long event;
79 };
80
81 /*
82 * clear and set bits on an given register on a given module
83 */
twl4030_clear_set(u8 mod_no,u8 clear,u8 set,u8 reg)84 static int twl4030_clear_set(u8 mod_no, u8 clear, u8 set, u8 reg)
85 {
86 u8 val = 0;
87 int ret;
88
89 ret = twl_i2c_read_u8(mod_no, &val, reg);
90 if (ret)
91 return ret;
92
93 val &= ~clear;
94 val |= set;
95
96 return twl_i2c_write_u8(mod_no, val, reg);
97 }
98
twl4030_bci_read(u8 reg,u8 * val)99 static int twl4030_bci_read(u8 reg, u8 *val)
100 {
101 return twl_i2c_read_u8(TWL4030_MODULE_MAIN_CHARGE, val, reg);
102 }
103
twl4030_clear_set_boot_bci(u8 clear,u8 set)104 static int twl4030_clear_set_boot_bci(u8 clear, u8 set)
105 {
106 return twl4030_clear_set(TWL4030_MODULE_PM_MASTER, 0,
107 TWL4030_CONFIG_DONE | TWL4030_BCIAUTOWEN | set,
108 TWL4030_PM_MASTER_BOOT_BCI);
109 }
110
twl4030bci_read_adc_val(u8 reg)111 static int twl4030bci_read_adc_val(u8 reg)
112 {
113 int ret, temp;
114 u8 val;
115
116 /* read MSB */
117 ret = twl4030_bci_read(reg + 1, &val);
118 if (ret)
119 return ret;
120
121 temp = (int)(val & 0x03) << 8;
122
123 /* read LSB */
124 ret = twl4030_bci_read(reg, &val);
125 if (ret)
126 return ret;
127
128 return temp | val;
129 }
130
131 /*
132 * Check if VBUS power is present
133 */
twl4030_bci_have_vbus(struct twl4030_bci * bci)134 static int twl4030_bci_have_vbus(struct twl4030_bci *bci)
135 {
136 int ret;
137 u8 hwsts;
138
139 ret = twl_i2c_read_u8(TWL4030_MODULE_PM_MASTER, &hwsts,
140 TWL4030_PM_MASTER_STS_HW_CONDITIONS);
141 if (ret < 0)
142 return 0;
143
144 dev_dbg(bci->dev, "check_vbus: HW_CONDITIONS %02x\n", hwsts);
145
146 /* in case we also have STS_USB_ID, VBUS is driven by TWL itself */
147 if ((hwsts & TWL4030_STS_VBUS) && !(hwsts & TWL4030_STS_USB_ID))
148 return 1;
149
150 return 0;
151 }
152
153 /*
154 * Enable/Disable USB Charge funtionality.
155 */
twl4030_charger_enable_usb(struct twl4030_bci * bci,bool enable)156 static int twl4030_charger_enable_usb(struct twl4030_bci *bci, bool enable)
157 {
158 int ret;
159
160 if (enable) {
161 /* Check for USB charger conneted */
162 if (!twl4030_bci_have_vbus(bci))
163 return -ENODEV;
164
165 /*
166 * Until we can find out what current the device can provide,
167 * require a module param to enable USB charging.
168 */
169 if (!allow_usb) {
170 dev_warn(bci->dev, "USB charging is disabled.\n");
171 return -EACCES;
172 }
173
174 /* forcing the field BCIAUTOUSB (BOOT_BCI[1]) to 1 */
175 ret = twl4030_clear_set_boot_bci(0, TWL4030_BCIAUTOUSB);
176 if (ret < 0)
177 return ret;
178
179 /* forcing USBFASTMCHG(BCIMFSTS4[2]) to 1 */
180 ret = twl4030_clear_set(TWL4030_MODULE_MAIN_CHARGE, 0,
181 TWL4030_USBFASTMCHG, TWL4030_BCIMFSTS4);
182 } else {
183 ret = twl4030_clear_set_boot_bci(TWL4030_BCIAUTOUSB, 0);
184 }
185
186 return ret;
187 }
188
189 /*
190 * Enable/Disable AC Charge funtionality.
191 */
twl4030_charger_enable_ac(bool enable)192 static int twl4030_charger_enable_ac(bool enable)
193 {
194 int ret;
195
196 if (enable)
197 ret = twl4030_clear_set_boot_bci(0, TWL4030_BCIAUTOAC);
198 else
199 ret = twl4030_clear_set_boot_bci(TWL4030_BCIAUTOAC, 0);
200
201 return ret;
202 }
203
204 /*
205 * TWL4030 CHG_PRES (AC charger presence) events
206 */
twl4030_charger_interrupt(int irq,void * arg)207 static irqreturn_t twl4030_charger_interrupt(int irq, void *arg)
208 {
209 struct twl4030_bci *bci = arg;
210
211 dev_dbg(bci->dev, "CHG_PRES irq\n");
212 power_supply_changed(&bci->ac);
213 power_supply_changed(&bci->usb);
214
215 return IRQ_HANDLED;
216 }
217
218 /*
219 * TWL4030 BCI monitoring events
220 */
twl4030_bci_interrupt(int irq,void * arg)221 static irqreturn_t twl4030_bci_interrupt(int irq, void *arg)
222 {
223 struct twl4030_bci *bci = arg;
224 u8 irqs1, irqs2;
225 int ret;
226
227 ret = twl_i2c_read_u8(TWL4030_MODULE_INTERRUPTS, &irqs1,
228 TWL4030_INTERRUPTS_BCIISR1A);
229 if (ret < 0)
230 return IRQ_HANDLED;
231
232 ret = twl_i2c_read_u8(TWL4030_MODULE_INTERRUPTS, &irqs2,
233 TWL4030_INTERRUPTS_BCIISR2A);
234 if (ret < 0)
235 return IRQ_HANDLED;
236
237 dev_dbg(bci->dev, "BCI irq %02x %02x\n", irqs2, irqs1);
238
239 if (irqs1 & (TWL4030_ICHGLOW | TWL4030_ICHGEOC)) {
240 /* charger state change, inform the core */
241 power_supply_changed(&bci->ac);
242 power_supply_changed(&bci->usb);
243 }
244
245 /* various monitoring events, for now we just log them here */
246 if (irqs1 & (TWL4030_TBATOR2 | TWL4030_TBATOR1))
247 dev_warn(bci->dev, "battery temperature out of range\n");
248
249 if (irqs1 & TWL4030_BATSTS)
250 dev_crit(bci->dev, "battery disconnected\n");
251
252 if (irqs2 & TWL4030_VBATOV)
253 dev_crit(bci->dev, "VBAT overvoltage\n");
254
255 if (irqs2 & TWL4030_VBUSOV)
256 dev_crit(bci->dev, "VBUS overvoltage\n");
257
258 if (irqs2 & TWL4030_ACCHGOV)
259 dev_crit(bci->dev, "Ac charger overvoltage\n");
260
261 return IRQ_HANDLED;
262 }
263
twl4030_bci_usb_work(struct work_struct * data)264 static void twl4030_bci_usb_work(struct work_struct *data)
265 {
266 struct twl4030_bci *bci = container_of(data, struct twl4030_bci, work);
267
268 switch (bci->event) {
269 case USB_EVENT_VBUS:
270 case USB_EVENT_CHARGER:
271 twl4030_charger_enable_usb(bci, true);
272 break;
273 case USB_EVENT_NONE:
274 twl4030_charger_enable_usb(bci, false);
275 break;
276 }
277 }
278
twl4030_bci_usb_ncb(struct notifier_block * nb,unsigned long val,void * priv)279 static int twl4030_bci_usb_ncb(struct notifier_block *nb, unsigned long val,
280 void *priv)
281 {
282 struct twl4030_bci *bci = container_of(nb, struct twl4030_bci, otg_nb);
283
284 dev_dbg(bci->dev, "OTG notify %lu\n", val);
285
286 bci->event = val;
287 schedule_work(&bci->work);
288
289 return NOTIFY_OK;
290 }
291
292 /*
293 * TI provided formulas:
294 * CGAIN == 0: ICHG = (BCIICHG * 1.7) / (2^10 - 1) - 0.85
295 * CGAIN == 1: ICHG = (BCIICHG * 3.4) / (2^10 - 1) - 1.7
296 * Here we use integer approximation of:
297 * CGAIN == 0: val * 1.6618 - 0.85
298 * CGAIN == 1: (val * 1.6618 - 0.85) * 2
299 */
twl4030_charger_get_current(void)300 static int twl4030_charger_get_current(void)
301 {
302 int curr;
303 int ret;
304 u8 bcictl1;
305
306 curr = twl4030bci_read_adc_val(TWL4030_BCIICHG);
307 if (curr < 0)
308 return curr;
309
310 ret = twl4030_bci_read(TWL4030_BCICTL1, &bcictl1);
311 if (ret)
312 return ret;
313
314 ret = (curr * 16618 - 850 * 10000) / 10;
315 if (bcictl1 & TWL4030_CGAIN)
316 ret *= 2;
317
318 return ret;
319 }
320
321 /*
322 * Returns the main charge FSM state
323 * Or < 0 on failure.
324 */
twl4030bci_state(struct twl4030_bci * bci)325 static int twl4030bci_state(struct twl4030_bci *bci)
326 {
327 int ret;
328 u8 state;
329
330 ret = twl4030_bci_read(TWL4030_BCIMSTATEC, &state);
331 if (ret) {
332 pr_err("twl4030_bci: error reading BCIMSTATEC\n");
333 return ret;
334 }
335
336 dev_dbg(bci->dev, "state: %02x\n", state);
337
338 return state;
339 }
340
twl4030_bci_state_to_status(int state)341 static int twl4030_bci_state_to_status(int state)
342 {
343 state &= TWL4030_MSTATEC_MASK;
344 if (TWL4030_MSTATEC_QUICK1 <= state && state <= TWL4030_MSTATEC_QUICK7)
345 return POWER_SUPPLY_STATUS_CHARGING;
346 else if (TWL4030_MSTATEC_COMPLETE1 <= state &&
347 state <= TWL4030_MSTATEC_COMPLETE4)
348 return POWER_SUPPLY_STATUS_FULL;
349 else
350 return POWER_SUPPLY_STATUS_NOT_CHARGING;
351 }
352
twl4030_bci_get_property(struct power_supply * psy,enum power_supply_property psp,union power_supply_propval * val)353 static int twl4030_bci_get_property(struct power_supply *psy,
354 enum power_supply_property psp,
355 union power_supply_propval *val)
356 {
357 struct twl4030_bci *bci = dev_get_drvdata(psy->dev->parent);
358 int is_charging;
359 int state;
360 int ret;
361
362 state = twl4030bci_state(bci);
363 if (state < 0)
364 return state;
365
366 if (psy->type == POWER_SUPPLY_TYPE_USB)
367 is_charging = state & TWL4030_MSTATEC_USB;
368 else
369 is_charging = state & TWL4030_MSTATEC_AC;
370
371 switch (psp) {
372 case POWER_SUPPLY_PROP_STATUS:
373 if (is_charging)
374 val->intval = twl4030_bci_state_to_status(state);
375 else
376 val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
377 break;
378 case POWER_SUPPLY_PROP_VOLTAGE_NOW:
379 /* charging must be active for meaningful result */
380 if (!is_charging)
381 return -ENODATA;
382 if (psy->type == POWER_SUPPLY_TYPE_USB) {
383 ret = twl4030bci_read_adc_val(TWL4030_BCIVBUS);
384 if (ret < 0)
385 return ret;
386 /* BCIVBUS uses ADCIN8, 7/1023 V/step */
387 val->intval = ret * 6843;
388 } else {
389 ret = twl4030bci_read_adc_val(TWL4030_BCIVAC);
390 if (ret < 0)
391 return ret;
392 /* BCIVAC uses ADCIN11, 10/1023 V/step */
393 val->intval = ret * 9775;
394 }
395 break;
396 case POWER_SUPPLY_PROP_CURRENT_NOW:
397 if (!is_charging)
398 return -ENODATA;
399 /* current measurement is shared between AC and USB */
400 ret = twl4030_charger_get_current();
401 if (ret < 0)
402 return ret;
403 val->intval = ret;
404 break;
405 case POWER_SUPPLY_PROP_ONLINE:
406 val->intval = is_charging &&
407 twl4030_bci_state_to_status(state) !=
408 POWER_SUPPLY_STATUS_NOT_CHARGING;
409 break;
410 default:
411 return -EINVAL;
412 }
413
414 return 0;
415 }
416
417 static enum power_supply_property twl4030_charger_props[] = {
418 POWER_SUPPLY_PROP_STATUS,
419 POWER_SUPPLY_PROP_ONLINE,
420 POWER_SUPPLY_PROP_VOLTAGE_NOW,
421 POWER_SUPPLY_PROP_CURRENT_NOW,
422 };
423
twl4030_bci_probe(struct platform_device * pdev)424 static int __init twl4030_bci_probe(struct platform_device *pdev)
425 {
426 struct twl4030_bci *bci;
427 int ret;
428 u32 reg;
429
430 bci = kzalloc(sizeof(*bci), GFP_KERNEL);
431 if (bci == NULL)
432 return -ENOMEM;
433
434 bci->dev = &pdev->dev;
435 bci->irq_chg = platform_get_irq(pdev, 0);
436 bci->irq_bci = platform_get_irq(pdev, 1);
437
438 platform_set_drvdata(pdev, bci);
439
440 bci->ac.name = "twl4030_ac";
441 bci->ac.type = POWER_SUPPLY_TYPE_MAINS;
442 bci->ac.properties = twl4030_charger_props;
443 bci->ac.num_properties = ARRAY_SIZE(twl4030_charger_props);
444 bci->ac.get_property = twl4030_bci_get_property;
445
446 ret = power_supply_register(&pdev->dev, &bci->ac);
447 if (ret) {
448 dev_err(&pdev->dev, "failed to register ac: %d\n", ret);
449 goto fail_register_ac;
450 }
451
452 bci->usb.name = "twl4030_usb";
453 bci->usb.type = POWER_SUPPLY_TYPE_USB;
454 bci->usb.properties = twl4030_charger_props;
455 bci->usb.num_properties = ARRAY_SIZE(twl4030_charger_props);
456 bci->usb.get_property = twl4030_bci_get_property;
457
458 ret = power_supply_register(&pdev->dev, &bci->usb);
459 if (ret) {
460 dev_err(&pdev->dev, "failed to register usb: %d\n", ret);
461 goto fail_register_usb;
462 }
463
464 ret = request_threaded_irq(bci->irq_chg, NULL,
465 twl4030_charger_interrupt, 0, pdev->name, bci);
466 if (ret < 0) {
467 dev_err(&pdev->dev, "could not request irq %d, status %d\n",
468 bci->irq_chg, ret);
469 goto fail_chg_irq;
470 }
471
472 ret = request_threaded_irq(bci->irq_bci, NULL,
473 twl4030_bci_interrupt, 0, pdev->name, bci);
474 if (ret < 0) {
475 dev_err(&pdev->dev, "could not request irq %d, status %d\n",
476 bci->irq_bci, ret);
477 goto fail_bci_irq;
478 }
479
480 INIT_WORK(&bci->work, twl4030_bci_usb_work);
481
482 bci->transceiver = otg_get_transceiver();
483 if (bci->transceiver != NULL) {
484 bci->otg_nb.notifier_call = twl4030_bci_usb_ncb;
485 otg_register_notifier(bci->transceiver, &bci->otg_nb);
486 }
487
488 /* Enable interrupts now. */
489 reg = ~(u32)(TWL4030_ICHGLOW | TWL4030_ICHGEOC | TWL4030_TBATOR2 |
490 TWL4030_TBATOR1 | TWL4030_BATSTS);
491 ret = twl_i2c_write_u8(TWL4030_MODULE_INTERRUPTS, reg,
492 TWL4030_INTERRUPTS_BCIIMR1A);
493 if (ret < 0) {
494 dev_err(&pdev->dev, "failed to unmask interrupts: %d\n", ret);
495 goto fail_unmask_interrupts;
496 }
497
498 reg = ~(u32)(TWL4030_VBATOV | TWL4030_VBUSOV | TWL4030_ACCHGOV);
499 ret = twl_i2c_write_u8(TWL4030_MODULE_INTERRUPTS, reg,
500 TWL4030_INTERRUPTS_BCIIMR2A);
501 if (ret < 0)
502 dev_warn(&pdev->dev, "failed to unmask interrupts: %d\n", ret);
503
504 twl4030_charger_enable_ac(true);
505 twl4030_charger_enable_usb(bci, true);
506
507 return 0;
508
509 fail_unmask_interrupts:
510 if (bci->transceiver != NULL) {
511 otg_unregister_notifier(bci->transceiver, &bci->otg_nb);
512 otg_put_transceiver(bci->transceiver);
513 }
514 free_irq(bci->irq_bci, bci);
515 fail_bci_irq:
516 free_irq(bci->irq_chg, bci);
517 fail_chg_irq:
518 power_supply_unregister(&bci->usb);
519 fail_register_usb:
520 power_supply_unregister(&bci->ac);
521 fail_register_ac:
522 platform_set_drvdata(pdev, NULL);
523 kfree(bci);
524
525 return ret;
526 }
527
twl4030_bci_remove(struct platform_device * pdev)528 static int __exit twl4030_bci_remove(struct platform_device *pdev)
529 {
530 struct twl4030_bci *bci = platform_get_drvdata(pdev);
531
532 twl4030_charger_enable_ac(false);
533 twl4030_charger_enable_usb(bci, false);
534
535 /* mask interrupts */
536 twl_i2c_write_u8(TWL4030_MODULE_INTERRUPTS, 0xff,
537 TWL4030_INTERRUPTS_BCIIMR1A);
538 twl_i2c_write_u8(TWL4030_MODULE_INTERRUPTS, 0xff,
539 TWL4030_INTERRUPTS_BCIIMR2A);
540
541 if (bci->transceiver != NULL) {
542 otg_unregister_notifier(bci->transceiver, &bci->otg_nb);
543 otg_put_transceiver(bci->transceiver);
544 }
545 free_irq(bci->irq_bci, bci);
546 free_irq(bci->irq_chg, bci);
547 power_supply_unregister(&bci->usb);
548 power_supply_unregister(&bci->ac);
549 platform_set_drvdata(pdev, NULL);
550 kfree(bci);
551
552 return 0;
553 }
554
555 static struct platform_driver twl4030_bci_driver = {
556 .driver = {
557 .name = "twl4030_bci",
558 .owner = THIS_MODULE,
559 },
560 .remove = __exit_p(twl4030_bci_remove),
561 };
562
twl4030_bci_init(void)563 static int __init twl4030_bci_init(void)
564 {
565 return platform_driver_probe(&twl4030_bci_driver, twl4030_bci_probe);
566 }
567 module_init(twl4030_bci_init);
568
twl4030_bci_exit(void)569 static void __exit twl4030_bci_exit(void)
570 {
571 platform_driver_unregister(&twl4030_bci_driver);
572 }
573 module_exit(twl4030_bci_exit);
574
575 MODULE_AUTHOR("Gražvydas Ignotas");
576 MODULE_DESCRIPTION("TWL4030 Battery Charger Interface driver");
577 MODULE_LICENSE("GPL");
578 MODULE_ALIAS("platform:twl4030_bci");
579