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/err.h>
19 #include <linux/platform_device.h>
20 #include <linux/interrupt.h>
21 #include <linux/i2c/twl.h>
22 #include <linux/power_supply.h>
23 #include <linux/notifier.h>
24 #include <linux/usb/otg.h>
25 #include <linux/iio/consumer.h>
26 
27 #define TWL4030_BCIMDEN		0x00
28 #define TWL4030_BCIMDKEY	0x01
29 #define TWL4030_BCIMSTATEC	0x02
30 #define TWL4030_BCIICHG		0x08
31 #define TWL4030_BCIVAC		0x0a
32 #define TWL4030_BCIVBUS		0x0c
33 #define TWL4030_BCIMFSTS3	0x0F
34 #define TWL4030_BCIMFSTS4	0x10
35 #define TWL4030_BCICTL1		0x23
36 #define TWL4030_BB_CFG		0x12
37 #define TWL4030_BCIIREF1	0x27
38 #define TWL4030_BCIIREF2	0x28
39 #define TWL4030_BCIMFKEY	0x11
40 #define TWL4030_BCIMFEN3	0x14
41 #define TWL4030_BCIMFTH8	0x1d
42 #define TWL4030_BCIMFTH9	0x1e
43 #define TWL4030_BCIWDKEY	0x21
44 
45 #define TWL4030_BCIMFSTS1	0x01
46 
47 #define TWL4030_BCIAUTOWEN	BIT(5)
48 #define TWL4030_CONFIG_DONE	BIT(4)
49 #define TWL4030_CVENAC		BIT(2)
50 #define TWL4030_BCIAUTOUSB	BIT(1)
51 #define TWL4030_BCIAUTOAC	BIT(0)
52 #define TWL4030_CGAIN		BIT(5)
53 #define TWL4030_USBFASTMCHG	BIT(2)
54 #define TWL4030_STS_VBUS	BIT(7)
55 #define TWL4030_STS_USB_ID	BIT(2)
56 #define TWL4030_BBCHEN		BIT(4)
57 #define TWL4030_BBSEL_MASK	0x0c
58 #define TWL4030_BBSEL_2V5	0x00
59 #define TWL4030_BBSEL_3V0	0x04
60 #define TWL4030_BBSEL_3V1	0x08
61 #define TWL4030_BBSEL_3V2	0x0c
62 #define TWL4030_BBISEL_MASK	0x03
63 #define TWL4030_BBISEL_25uA	0x00
64 #define TWL4030_BBISEL_150uA	0x01
65 #define TWL4030_BBISEL_500uA	0x02
66 #define TWL4030_BBISEL_1000uA	0x03
67 
68 #define TWL4030_BATSTSPCHG	BIT(2)
69 #define TWL4030_BATSTSMCHG	BIT(6)
70 
71 /* BCI interrupts */
72 #define TWL4030_WOVF		BIT(0) /* Watchdog overflow */
73 #define TWL4030_TMOVF		BIT(1) /* Timer overflow */
74 #define TWL4030_ICHGHIGH	BIT(2) /* Battery charge current high */
75 #define TWL4030_ICHGLOW		BIT(3) /* Battery cc. low / FSM state change */
76 #define TWL4030_ICHGEOC		BIT(4) /* Battery current end-of-charge */
77 #define TWL4030_TBATOR2		BIT(5) /* Battery temperature out of range 2 */
78 #define TWL4030_TBATOR1		BIT(6) /* Battery temperature out of range 1 */
79 #define TWL4030_BATSTS		BIT(7) /* Battery status */
80 
81 #define TWL4030_VBATLVL		BIT(0) /* VBAT level */
82 #define TWL4030_VBATOV		BIT(1) /* VBAT overvoltage */
83 #define TWL4030_VBUSOV		BIT(2) /* VBUS overvoltage */
84 #define TWL4030_ACCHGOV		BIT(3) /* Ac charger overvoltage */
85 
86 #define TWL4030_MSTATEC_USB		BIT(4)
87 #define TWL4030_MSTATEC_AC		BIT(5)
88 #define TWL4030_MSTATEC_MASK		0x0f
89 #define TWL4030_MSTATEC_QUICK1		0x02
90 #define TWL4030_MSTATEC_QUICK7		0x07
91 #define TWL4030_MSTATEC_COMPLETE1	0x0b
92 #define TWL4030_MSTATEC_COMPLETE4	0x0e
93 
94 /*
95  * If AC (Accessory Charger) voltage exceeds 4.5V (MADC 11)
96  * then AC is available.
97  */
98 static inline int ac_available(struct iio_channel *channel_vac)
99 {
100 	int val, err;
101 
102 	if (!channel_vac)
103 		return 0;
104 
105 	err = iio_read_channel_processed(channel_vac, &val);
106 	if (err < 0)
107 		return 0;
108 	return val > 4500;
109 }
110 
111 static bool allow_usb;
112 module_param(allow_usb, bool, 0644);
113 MODULE_PARM_DESC(allow_usb, "Allow USB charge drawing default current");
114 
115 struct twl4030_bci {
116 	struct device		*dev;
117 	struct power_supply	*ac;
118 	struct power_supply	*usb;
119 	struct usb_phy		*transceiver;
120 	struct notifier_block	usb_nb;
121 	struct work_struct	work;
122 	int			irq_chg;
123 	int			irq_bci;
124 	int			usb_enabled;
125 
126 	/*
127 	 * ichg_* and *_cur values in uA. If any are 'large', we set
128 	 * CGAIN to '1' which doubles the range for half the
129 	 * precision.
130 	 */
131 	unsigned int		ichg_eoc, ichg_lo, ichg_hi;
132 	unsigned int		usb_cur, ac_cur;
133 	struct iio_channel	*channel_vac;
134 	bool			ac_is_active;
135 	int			usb_mode, ac_mode; /* charging mode requested */
136 #define	CHARGE_OFF	0
137 #define	CHARGE_AUTO	1
138 #define	CHARGE_LINEAR	2
139 
140 	/* When setting the USB current we slowly increase the
141 	 * requested current until target is reached or the voltage
142 	 * drops below 4.75V.  In the latter case we step back one
143 	 * step.
144 	 */
145 	unsigned int		usb_cur_target;
146 	struct delayed_work	current_worker;
147 #define	USB_CUR_STEP	20000	/* 20mA at a time */
148 #define	USB_MIN_VOLT	4750000	/* 4.75V */
149 #define	USB_CUR_DELAY	msecs_to_jiffies(100)
150 #define	USB_MAX_CURRENT	1700000 /* TWL4030 caps at 1.7A */
151 
152 	unsigned long		event;
153 };
154 
155 /* strings for 'usb_mode' values */
156 static char *modes[] = { "off", "auto", "continuous" };
157 
158 /*
159  * clear and set bits on an given register on a given module
160  */
161 static int twl4030_clear_set(u8 mod_no, u8 clear, u8 set, u8 reg)
162 {
163 	u8 val = 0;
164 	int ret;
165 
166 	ret = twl_i2c_read_u8(mod_no, &val, reg);
167 	if (ret)
168 		return ret;
169 
170 	val &= ~clear;
171 	val |= set;
172 
173 	return twl_i2c_write_u8(mod_no, val, reg);
174 }
175 
176 static int twl4030_bci_read(u8 reg, u8 *val)
177 {
178 	return twl_i2c_read_u8(TWL_MODULE_MAIN_CHARGE, val, reg);
179 }
180 
181 static int twl4030_clear_set_boot_bci(u8 clear, u8 set)
182 {
183 	return twl4030_clear_set(TWL_MODULE_PM_MASTER, clear,
184 			TWL4030_CONFIG_DONE | TWL4030_BCIAUTOWEN | set,
185 			TWL4030_PM_MASTER_BOOT_BCI);
186 }
187 
188 static int twl4030bci_read_adc_val(u8 reg)
189 {
190 	int ret, temp;
191 	u8 val;
192 
193 	/* read MSB */
194 	ret = twl4030_bci_read(reg + 1, &val);
195 	if (ret)
196 		return ret;
197 
198 	temp = (int)(val & 0x03) << 8;
199 
200 	/* read LSB */
201 	ret = twl4030_bci_read(reg, &val);
202 	if (ret)
203 		return ret;
204 
205 	return temp | val;
206 }
207 
208 /*
209  * Check if Battery Pack was present
210  */
211 static int twl4030_is_battery_present(struct twl4030_bci *bci)
212 {
213 	int ret;
214 	u8 val = 0;
215 
216 	/* Battery presence in Main charge? */
217 	ret = twl_i2c_read_u8(TWL_MODULE_MAIN_CHARGE, &val, TWL4030_BCIMFSTS3);
218 	if (ret)
219 		return ret;
220 	if (val & TWL4030_BATSTSMCHG)
221 		return 0;
222 
223 	/*
224 	 * OK, It could be that bootloader did not enable main charger,
225 	 * pre-charge is h/w auto. So, Battery presence in Pre-charge?
226 	 */
227 	ret = twl_i2c_read_u8(TWL4030_MODULE_PRECHARGE, &val,
228 			      TWL4030_BCIMFSTS1);
229 	if (ret)
230 		return ret;
231 	if (val & TWL4030_BATSTSPCHG)
232 		return 0;
233 
234 	return -ENODEV;
235 }
236 
237 /*
238  * TI provided formulas:
239  * CGAIN == 0: ICHG = (BCIICHG * 1.7) / (2^10 - 1) - 0.85
240  * CGAIN == 1: ICHG = (BCIICHG * 3.4) / (2^10 - 1) - 1.7
241  * Here we use integer approximation of:
242  * CGAIN == 0: val * 1.6618 - 0.85 * 1000
243  * CGAIN == 1: (val * 1.6618 - 0.85 * 1000) * 2
244  */
245 /*
246  * convert twl register value for currents into uA
247  */
248 static int regval2ua(int regval, bool cgain)
249 {
250 	if (cgain)
251 		return (regval * 16618 - 8500 * 1000) / 5;
252 	else
253 		return (regval * 16618 - 8500 * 1000) / 10;
254 }
255 
256 /*
257  * convert uA currents into twl register value
258  */
259 static int ua2regval(int ua, bool cgain)
260 {
261 	int ret;
262 	if (cgain)
263 		ua /= 2;
264 	ret = (ua * 10 + 8500 * 1000) / 16618;
265 	/* rounding problems */
266 	if (ret < 512)
267 		ret = 512;
268 	return ret;
269 }
270 
271 static int twl4030_charger_update_current(struct twl4030_bci *bci)
272 {
273 	int status;
274 	int cur;
275 	unsigned reg, cur_reg;
276 	u8 bcictl1, oldreg, fullreg;
277 	bool cgain = false;
278 	u8 boot_bci;
279 
280 	/*
281 	 * If AC (Accessory Charger) voltage exceeds 4.5V (MADC 11)
282 	 * and AC is enabled, set current for 'ac'
283 	 */
284 	if (ac_available(bci->channel_vac)) {
285 		cur = bci->ac_cur;
286 		bci->ac_is_active = true;
287 	} else {
288 		cur = bci->usb_cur;
289 		bci->ac_is_active = false;
290 		if (cur > bci->usb_cur_target) {
291 			cur = bci->usb_cur_target;
292 			bci->usb_cur = cur;
293 		}
294 		if (cur < bci->usb_cur_target)
295 			schedule_delayed_work(&bci->current_worker, USB_CUR_DELAY);
296 	}
297 
298 	/* First, check thresholds and see if cgain is needed */
299 	if (bci->ichg_eoc >= 200000)
300 		cgain = true;
301 	if (bci->ichg_lo >= 400000)
302 		cgain = true;
303 	if (bci->ichg_hi >= 820000)
304 		cgain = true;
305 	if (cur > 852000)
306 		cgain = true;
307 
308 	status = twl4030_bci_read(TWL4030_BCICTL1, &bcictl1);
309 	if (status < 0)
310 		return status;
311 	if (twl_i2c_read_u8(TWL_MODULE_PM_MASTER, &boot_bci,
312 			    TWL4030_PM_MASTER_BOOT_BCI) < 0)
313 		boot_bci = 0;
314 	boot_bci &= 7;
315 
316 	if ((!!cgain) != !!(bcictl1 & TWL4030_CGAIN))
317 		/* Need to turn for charging while we change the
318 		 * CGAIN bit.  Leave it off while everything is
319 		 * updated.
320 		 */
321 		twl4030_clear_set_boot_bci(boot_bci, 0);
322 
323 	/*
324 	 * For ichg_eoc, the hardware only supports reg values matching
325 	 * 100XXXX000, and requires the XXXX be stored in the high nibble
326 	 * of TWL4030_BCIMFTH8.
327 	 */
328 	reg = ua2regval(bci->ichg_eoc, cgain);
329 	if (reg > 0x278)
330 		reg = 0x278;
331 	if (reg < 0x200)
332 		reg = 0x200;
333 	reg = (reg >> 3) & 0xf;
334 	fullreg = reg << 4;
335 
336 	/*
337 	 * For ichg_lo, reg value must match 10XXXX0000.
338 	 * XXXX is stored in low nibble of TWL4030_BCIMFTH8.
339 	 */
340 	reg = ua2regval(bci->ichg_lo, cgain);
341 	if (reg > 0x2F0)
342 		reg = 0x2F0;
343 	if (reg < 0x200)
344 		reg = 0x200;
345 	reg = (reg >> 4) & 0xf;
346 	fullreg |= reg;
347 
348 	/* ichg_eoc and ichg_lo live in same register */
349 	status = twl4030_bci_read(TWL4030_BCIMFTH8, &oldreg);
350 	if (status < 0)
351 		return status;
352 	if (oldreg != fullreg) {
353 		status = twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE, 0xF4,
354 					  TWL4030_BCIMFKEY);
355 		if (status < 0)
356 			return status;
357 		twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE,
358 				 fullreg, TWL4030_BCIMFTH8);
359 	}
360 
361 	/* ichg_hi threshold must be 1XXXX01100 (I think) */
362 	reg = ua2regval(bci->ichg_hi, cgain);
363 	if (reg > 0x3E0)
364 		reg = 0x3E0;
365 	if (reg < 0x200)
366 		reg = 0x200;
367 	fullreg = (reg >> 5) & 0xF;
368 	fullreg <<= 4;
369 	status = twl4030_bci_read(TWL4030_BCIMFTH9, &oldreg);
370 	if (status < 0)
371 		return status;
372 	if ((oldreg & 0xF0) != fullreg) {
373 		fullreg |= (oldreg & 0x0F);
374 		status = twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE, 0xE7,
375 					  TWL4030_BCIMFKEY);
376 		if (status < 0)
377 			return status;
378 		twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE,
379 				 fullreg, TWL4030_BCIMFTH9);
380 	}
381 
382 	/*
383 	 * And finally, set the current.  This is stored in
384 	 * two registers.
385 	 */
386 	reg = ua2regval(cur, cgain);
387 	/* we have only 10 bits */
388 	if (reg > 0x3ff)
389 		reg = 0x3ff;
390 	status = twl4030_bci_read(TWL4030_BCIIREF1, &oldreg);
391 	if (status < 0)
392 		return status;
393 	cur_reg = oldreg;
394 	status = twl4030_bci_read(TWL4030_BCIIREF2, &oldreg);
395 	if (status < 0)
396 		return status;
397 	cur_reg |= oldreg << 8;
398 	if (reg != oldreg) {
399 		/* disable write protection for one write access for
400 		 * BCIIREF */
401 		status = twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE, 0xE7,
402 					  TWL4030_BCIMFKEY);
403 		if (status < 0)
404 			return status;
405 		status = twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE,
406 					  (reg & 0x100) ? 3 : 2,
407 					  TWL4030_BCIIREF2);
408 		if (status < 0)
409 			return status;
410 		/* disable write protection for one write access for
411 		 * BCIIREF */
412 		status = twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE, 0xE7,
413 					  TWL4030_BCIMFKEY);
414 		if (status < 0)
415 			return status;
416 		status = twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE,
417 					  reg & 0xff,
418 					  TWL4030_BCIIREF1);
419 	}
420 	if ((!!cgain) != !!(bcictl1 & TWL4030_CGAIN)) {
421 		/* Flip CGAIN and re-enable charging */
422 		bcictl1 ^= TWL4030_CGAIN;
423 		twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE,
424 				 bcictl1, TWL4030_BCICTL1);
425 		twl4030_clear_set_boot_bci(0, boot_bci);
426 	}
427 	return 0;
428 }
429 
430 static int twl4030_charger_get_current(void);
431 
432 static void twl4030_current_worker(struct work_struct *data)
433 {
434 	int v, curr;
435 	int res;
436 	struct twl4030_bci *bci = container_of(data, struct twl4030_bci,
437 					       current_worker.work);
438 
439 	res = twl4030bci_read_adc_val(TWL4030_BCIVBUS);
440 	if (res < 0)
441 		v = 0;
442 	else
443 		/* BCIVBUS uses ADCIN8, 7/1023 V/step */
444 		v = res * 6843;
445 	curr = twl4030_charger_get_current();
446 
447 	dev_dbg(bci->dev, "v=%d cur=%d limit=%d target=%d\n", v, curr,
448 		bci->usb_cur, bci->usb_cur_target);
449 
450 	if (v < USB_MIN_VOLT) {
451 		/* Back up and stop adjusting. */
452 		bci->usb_cur -= USB_CUR_STEP;
453 		bci->usb_cur_target = bci->usb_cur;
454 	} else if (bci->usb_cur >= bci->usb_cur_target ||
455 		   bci->usb_cur + USB_CUR_STEP > USB_MAX_CURRENT) {
456 		/* Reached target and voltage is OK - stop */
457 		return;
458 	} else {
459 		bci->usb_cur += USB_CUR_STEP;
460 		schedule_delayed_work(&bci->current_worker, USB_CUR_DELAY);
461 	}
462 	twl4030_charger_update_current(bci);
463 }
464 
465 /*
466  * Enable/Disable USB Charge functionality.
467  */
468 static int twl4030_charger_enable_usb(struct twl4030_bci *bci, bool enable)
469 {
470 	int ret;
471 
472 	if (bci->usb_mode == CHARGE_OFF)
473 		enable = false;
474 	if (enable && !IS_ERR_OR_NULL(bci->transceiver)) {
475 
476 		twl4030_charger_update_current(bci);
477 
478 		/* Need to keep phy powered */
479 		if (!bci->usb_enabled) {
480 			pm_runtime_get_sync(bci->transceiver->dev);
481 			bci->usb_enabled = 1;
482 		}
483 
484 		if (bci->usb_mode == CHARGE_AUTO)
485 			/* forcing the field BCIAUTOUSB (BOOT_BCI[1]) to 1 */
486 			ret = twl4030_clear_set_boot_bci(0, TWL4030_BCIAUTOUSB);
487 
488 		/* forcing USBFASTMCHG(BCIMFSTS4[2]) to 1 */
489 		ret = twl4030_clear_set(TWL_MODULE_MAIN_CHARGE, 0,
490 			TWL4030_USBFASTMCHG, TWL4030_BCIMFSTS4);
491 		if (bci->usb_mode == CHARGE_LINEAR) {
492 			twl4030_clear_set_boot_bci(TWL4030_BCIAUTOAC|TWL4030_CVENAC, 0);
493 			/* Watch dog key: WOVF acknowledge */
494 			ret = twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE, 0x33,
495 					       TWL4030_BCIWDKEY);
496 			/* 0x24 + EKEY6: off mode */
497 			ret = twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE, 0x2a,
498 					       TWL4030_BCIMDKEY);
499 			/* EKEY2: Linear charge: USB path */
500 			ret = twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE, 0x26,
501 					       TWL4030_BCIMDKEY);
502 			/* WDKEY5: stop watchdog count */
503 			ret = twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE, 0xf3,
504 					       TWL4030_BCIWDKEY);
505 			/* enable MFEN3 access */
506 			ret = twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE, 0x9c,
507 					       TWL4030_BCIMFKEY);
508 			 /* ICHGEOCEN - end-of-charge monitor (current < 80mA)
509 			  *                      (charging continues)
510 			  * ICHGLOWEN - current level monitor (charge continues)
511 			  * don't monitor over-current or heat save
512 			  */
513 			ret = twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE, 0xf0,
514 					       TWL4030_BCIMFEN3);
515 		}
516 	} else {
517 		ret = twl4030_clear_set_boot_bci(TWL4030_BCIAUTOUSB, 0);
518 		ret |= twl_i2c_write_u8(TWL_MODULE_MAIN_CHARGE, 0x2a,
519 					TWL4030_BCIMDKEY);
520 		if (bci->usb_enabled) {
521 			pm_runtime_mark_last_busy(bci->transceiver->dev);
522 			pm_runtime_put_autosuspend(bci->transceiver->dev);
523 			bci->usb_enabled = 0;
524 		}
525 		bci->usb_cur = 0;
526 	}
527 
528 	return ret;
529 }
530 
531 /*
532  * Enable/Disable AC Charge funtionality.
533  */
534 static int twl4030_charger_enable_ac(struct twl4030_bci *bci, bool enable)
535 {
536 	int ret;
537 
538 	if (bci->ac_mode == CHARGE_OFF)
539 		enable = false;
540 
541 	if (enable)
542 		ret = twl4030_clear_set_boot_bci(0, TWL4030_BCIAUTOAC);
543 	else
544 		ret = twl4030_clear_set_boot_bci(TWL4030_BCIAUTOAC, 0);
545 
546 	return ret;
547 }
548 
549 /*
550  * Enable/Disable charging of Backup Battery.
551  */
552 static int twl4030_charger_enable_backup(int uvolt, int uamp)
553 {
554 	int ret;
555 	u8 flags;
556 
557 	if (uvolt < 2500000 ||
558 	    uamp < 25) {
559 		/* disable charging of backup battery */
560 		ret = twl4030_clear_set(TWL_MODULE_PM_RECEIVER,
561 					TWL4030_BBCHEN, 0, TWL4030_BB_CFG);
562 		return ret;
563 	}
564 
565 	flags = TWL4030_BBCHEN;
566 	if (uvolt >= 3200000)
567 		flags |= TWL4030_BBSEL_3V2;
568 	else if (uvolt >= 3100000)
569 		flags |= TWL4030_BBSEL_3V1;
570 	else if (uvolt >= 3000000)
571 		flags |= TWL4030_BBSEL_3V0;
572 	else
573 		flags |= TWL4030_BBSEL_2V5;
574 
575 	if (uamp >= 1000)
576 		flags |= TWL4030_BBISEL_1000uA;
577 	else if (uamp >= 500)
578 		flags |= TWL4030_BBISEL_500uA;
579 	else if (uamp >= 150)
580 		flags |= TWL4030_BBISEL_150uA;
581 	else
582 		flags |= TWL4030_BBISEL_25uA;
583 
584 	ret = twl4030_clear_set(TWL_MODULE_PM_RECEIVER,
585 				TWL4030_BBSEL_MASK | TWL4030_BBISEL_MASK,
586 				flags,
587 				TWL4030_BB_CFG);
588 
589 	return ret;
590 }
591 
592 /*
593  * TWL4030 CHG_PRES (AC charger presence) events
594  */
595 static irqreturn_t twl4030_charger_interrupt(int irq, void *arg)
596 {
597 	struct twl4030_bci *bci = arg;
598 
599 	dev_dbg(bci->dev, "CHG_PRES irq\n");
600 	/* reset current on each 'plug' event */
601 	bci->ac_cur = 500000;
602 	twl4030_charger_update_current(bci);
603 	power_supply_changed(bci->ac);
604 	power_supply_changed(bci->usb);
605 
606 	return IRQ_HANDLED;
607 }
608 
609 /*
610  * TWL4030 BCI monitoring events
611  */
612 static irqreturn_t twl4030_bci_interrupt(int irq, void *arg)
613 {
614 	struct twl4030_bci *bci = arg;
615 	u8 irqs1, irqs2;
616 	int ret;
617 
618 	ret = twl_i2c_read_u8(TWL4030_MODULE_INTERRUPTS, &irqs1,
619 			      TWL4030_INTERRUPTS_BCIISR1A);
620 	if (ret < 0)
621 		return IRQ_HANDLED;
622 
623 	ret = twl_i2c_read_u8(TWL4030_MODULE_INTERRUPTS, &irqs2,
624 			      TWL4030_INTERRUPTS_BCIISR2A);
625 	if (ret < 0)
626 		return IRQ_HANDLED;
627 
628 	dev_dbg(bci->dev, "BCI irq %02x %02x\n", irqs2, irqs1);
629 
630 	if (irqs1 & (TWL4030_ICHGLOW | TWL4030_ICHGEOC)) {
631 		/* charger state change, inform the core */
632 		power_supply_changed(bci->ac);
633 		power_supply_changed(bci->usb);
634 	}
635 	twl4030_charger_update_current(bci);
636 
637 	/* various monitoring events, for now we just log them here */
638 	if (irqs1 & (TWL4030_TBATOR2 | TWL4030_TBATOR1))
639 		dev_warn(bci->dev, "battery temperature out of range\n");
640 
641 	if (irqs1 & TWL4030_BATSTS)
642 		dev_crit(bci->dev, "battery disconnected\n");
643 
644 	if (irqs2 & TWL4030_VBATOV)
645 		dev_crit(bci->dev, "VBAT overvoltage\n");
646 
647 	if (irqs2 & TWL4030_VBUSOV)
648 		dev_crit(bci->dev, "VBUS overvoltage\n");
649 
650 	if (irqs2 & TWL4030_ACCHGOV)
651 		dev_crit(bci->dev, "Ac charger overvoltage\n");
652 
653 	return IRQ_HANDLED;
654 }
655 
656 /*
657  * Provide "max_current" attribute in sysfs.
658  */
659 static ssize_t
660 twl4030_bci_max_current_store(struct device *dev, struct device_attribute *attr,
661 	const char *buf, size_t n)
662 {
663 	struct twl4030_bci *bci = dev_get_drvdata(dev->parent);
664 	int cur = 0;
665 	int status = 0;
666 	status = kstrtoint(buf, 10, &cur);
667 	if (status)
668 		return status;
669 	if (cur < 0)
670 		return -EINVAL;
671 	if (dev == &bci->ac->dev)
672 		bci->ac_cur = cur;
673 	else
674 		bci->usb_cur_target = cur;
675 
676 	twl4030_charger_update_current(bci);
677 	return n;
678 }
679 
680 /*
681  * sysfs max_current show
682  */
683 static ssize_t twl4030_bci_max_current_show(struct device *dev,
684 	struct device_attribute *attr, char *buf)
685 {
686 	int status = 0;
687 	int cur = -1;
688 	u8 bcictl1;
689 	struct twl4030_bci *bci = dev_get_drvdata(dev->parent);
690 
691 	if (dev == &bci->ac->dev) {
692 		if (!bci->ac_is_active)
693 			cur = bci->ac_cur;
694 	} else {
695 		if (bci->ac_is_active)
696 			cur = bci->usb_cur_target;
697 	}
698 	if (cur < 0) {
699 		cur = twl4030bci_read_adc_val(TWL4030_BCIIREF1);
700 		if (cur < 0)
701 			return cur;
702 		status = twl4030_bci_read(TWL4030_BCICTL1, &bcictl1);
703 		if (status < 0)
704 			return status;
705 		cur = regval2ua(cur, bcictl1 & TWL4030_CGAIN);
706 	}
707 	return scnprintf(buf, PAGE_SIZE, "%u\n", cur);
708 }
709 
710 static DEVICE_ATTR(max_current, 0644, twl4030_bci_max_current_show,
711 			twl4030_bci_max_current_store);
712 
713 static void twl4030_bci_usb_work(struct work_struct *data)
714 {
715 	struct twl4030_bci *bci = container_of(data, struct twl4030_bci, work);
716 
717 	switch (bci->event) {
718 	case USB_EVENT_VBUS:
719 	case USB_EVENT_CHARGER:
720 		twl4030_charger_enable_usb(bci, true);
721 		break;
722 	case USB_EVENT_NONE:
723 		twl4030_charger_enable_usb(bci, false);
724 		break;
725 	}
726 }
727 
728 static int twl4030_bci_usb_ncb(struct notifier_block *nb, unsigned long val,
729 			       void *priv)
730 {
731 	struct twl4030_bci *bci = container_of(nb, struct twl4030_bci, usb_nb);
732 
733 	dev_dbg(bci->dev, "OTG notify %lu\n", val);
734 
735 	/* reset current on each 'plug' event */
736 	if (allow_usb)
737 		bci->usb_cur_target = 500000;
738 	else
739 		bci->usb_cur_target = 100000;
740 
741 	bci->event = val;
742 	schedule_work(&bci->work);
743 
744 	return NOTIFY_OK;
745 }
746 
747 /*
748  * sysfs charger enabled store
749  */
750 static ssize_t
751 twl4030_bci_mode_store(struct device *dev, struct device_attribute *attr,
752 			  const char *buf, size_t n)
753 {
754 	struct twl4030_bci *bci = dev_get_drvdata(dev->parent);
755 	int mode;
756 	int status;
757 
758 	if (sysfs_streq(buf, modes[0]))
759 		mode = 0;
760 	else if (sysfs_streq(buf, modes[1]))
761 		mode = 1;
762 	else if (sysfs_streq(buf, modes[2]))
763 		mode = 2;
764 	else
765 		return -EINVAL;
766 	if (dev == &bci->ac->dev) {
767 		if (mode == 2)
768 			return -EINVAL;
769 		twl4030_charger_enable_ac(bci, false);
770 		bci->ac_mode = mode;
771 		status = twl4030_charger_enable_ac(bci, true);
772 	} else {
773 		twl4030_charger_enable_usb(bci, false);
774 		bci->usb_mode = mode;
775 		status = twl4030_charger_enable_usb(bci, true);
776 	}
777 	return (status == 0) ? n : status;
778 }
779 
780 /*
781  * sysfs charger enabled show
782  */
783 static ssize_t
784 twl4030_bci_mode_show(struct device *dev,
785 			     struct device_attribute *attr, char *buf)
786 {
787 	struct twl4030_bci *bci = dev_get_drvdata(dev->parent);
788 	int len = 0;
789 	int i;
790 	int mode = bci->usb_mode;
791 
792 	if (dev == &bci->ac->dev)
793 		mode = bci->ac_mode;
794 
795 	for (i = 0; i < ARRAY_SIZE(modes); i++)
796 		if (mode == i)
797 			len += snprintf(buf+len, PAGE_SIZE-len,
798 					"[%s] ", modes[i]);
799 		else
800 			len += snprintf(buf+len, PAGE_SIZE-len,
801 					"%s ", modes[i]);
802 	buf[len-1] = '\n';
803 	return len;
804 }
805 static DEVICE_ATTR(mode, 0644, twl4030_bci_mode_show,
806 		   twl4030_bci_mode_store);
807 
808 static int twl4030_charger_get_current(void)
809 {
810 	int curr;
811 	int ret;
812 	u8 bcictl1;
813 
814 	curr = twl4030bci_read_adc_val(TWL4030_BCIICHG);
815 	if (curr < 0)
816 		return curr;
817 
818 	ret = twl4030_bci_read(TWL4030_BCICTL1, &bcictl1);
819 	if (ret)
820 		return ret;
821 
822 	return regval2ua(curr, bcictl1 & TWL4030_CGAIN);
823 }
824 
825 /*
826  * Returns the main charge FSM state
827  * Or < 0 on failure.
828  */
829 static int twl4030bci_state(struct twl4030_bci *bci)
830 {
831 	int ret;
832 	u8 state;
833 
834 	ret = twl4030_bci_read(TWL4030_BCIMSTATEC, &state);
835 	if (ret) {
836 		pr_err("twl4030_bci: error reading BCIMSTATEC\n");
837 		return ret;
838 	}
839 
840 	dev_dbg(bci->dev, "state: %02x\n", state);
841 
842 	return state;
843 }
844 
845 static int twl4030_bci_state_to_status(int state)
846 {
847 	state &= TWL4030_MSTATEC_MASK;
848 	if (TWL4030_MSTATEC_QUICK1 <= state && state <= TWL4030_MSTATEC_QUICK7)
849 		return POWER_SUPPLY_STATUS_CHARGING;
850 	else if (TWL4030_MSTATEC_COMPLETE1 <= state &&
851 					state <= TWL4030_MSTATEC_COMPLETE4)
852 		return POWER_SUPPLY_STATUS_FULL;
853 	else
854 		return POWER_SUPPLY_STATUS_NOT_CHARGING;
855 }
856 
857 static int twl4030_bci_get_property(struct power_supply *psy,
858 				    enum power_supply_property psp,
859 				    union power_supply_propval *val)
860 {
861 	struct twl4030_bci *bci = dev_get_drvdata(psy->dev.parent);
862 	int is_charging;
863 	int state;
864 	int ret;
865 
866 	state = twl4030bci_state(bci);
867 	if (state < 0)
868 		return state;
869 
870 	if (psy->desc->type == POWER_SUPPLY_TYPE_USB)
871 		is_charging = state & TWL4030_MSTATEC_USB;
872 	else
873 		is_charging = state & TWL4030_MSTATEC_AC;
874 	if (!is_charging) {
875 		u8 s;
876 		twl4030_bci_read(TWL4030_BCIMDEN, &s);
877 		if (psy->desc->type == POWER_SUPPLY_TYPE_USB)
878 			is_charging = s & 1;
879 		else
880 			is_charging = s & 2;
881 		if (is_charging)
882 			/* A little white lie */
883 			state = TWL4030_MSTATEC_QUICK1;
884 	}
885 
886 	switch (psp) {
887 	case POWER_SUPPLY_PROP_STATUS:
888 		if (is_charging)
889 			val->intval = twl4030_bci_state_to_status(state);
890 		else
891 			val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
892 		break;
893 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
894 		/* charging must be active for meaningful result */
895 		if (!is_charging)
896 			return -ENODATA;
897 		if (psy->desc->type == POWER_SUPPLY_TYPE_USB) {
898 			ret = twl4030bci_read_adc_val(TWL4030_BCIVBUS);
899 			if (ret < 0)
900 				return ret;
901 			/* BCIVBUS uses ADCIN8, 7/1023 V/step */
902 			val->intval = ret * 6843;
903 		} else {
904 			ret = twl4030bci_read_adc_val(TWL4030_BCIVAC);
905 			if (ret < 0)
906 				return ret;
907 			/* BCIVAC uses ADCIN11, 10/1023 V/step */
908 			val->intval = ret * 9775;
909 		}
910 		break;
911 	case POWER_SUPPLY_PROP_CURRENT_NOW:
912 		if (!is_charging)
913 			return -ENODATA;
914 		/* current measurement is shared between AC and USB */
915 		ret = twl4030_charger_get_current();
916 		if (ret < 0)
917 			return ret;
918 		val->intval = ret;
919 		break;
920 	case POWER_SUPPLY_PROP_ONLINE:
921 		val->intval = is_charging &&
922 			twl4030_bci_state_to_status(state) !=
923 				POWER_SUPPLY_STATUS_NOT_CHARGING;
924 		break;
925 	default:
926 		return -EINVAL;
927 	}
928 
929 	return 0;
930 }
931 
932 static enum power_supply_property twl4030_charger_props[] = {
933 	POWER_SUPPLY_PROP_STATUS,
934 	POWER_SUPPLY_PROP_ONLINE,
935 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
936 	POWER_SUPPLY_PROP_CURRENT_NOW,
937 };
938 
939 #ifdef CONFIG_OF
940 static const struct twl4030_bci_platform_data *
941 twl4030_bci_parse_dt(struct device *dev)
942 {
943 	struct device_node *np = dev->of_node;
944 	struct twl4030_bci_platform_data *pdata;
945 	u32 num;
946 
947 	if (!np)
948 		return NULL;
949 	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
950 	if (!pdata)
951 		return pdata;
952 
953 	if (of_property_read_u32(np, "ti,bb-uvolt", &num) == 0)
954 		pdata->bb_uvolt = num;
955 	if (of_property_read_u32(np, "ti,bb-uamp", &num) == 0)
956 		pdata->bb_uamp = num;
957 	return pdata;
958 }
959 #else
960 static inline const struct twl4030_bci_platform_data *
961 twl4030_bci_parse_dt(struct device *dev)
962 {
963 	return NULL;
964 }
965 #endif
966 
967 static const struct power_supply_desc twl4030_bci_ac_desc = {
968 	.name		= "twl4030_ac",
969 	.type		= POWER_SUPPLY_TYPE_MAINS,
970 	.properties	= twl4030_charger_props,
971 	.num_properties	= ARRAY_SIZE(twl4030_charger_props),
972 	.get_property	= twl4030_bci_get_property,
973 };
974 
975 static const struct power_supply_desc twl4030_bci_usb_desc = {
976 	.name		= "twl4030_usb",
977 	.type		= POWER_SUPPLY_TYPE_USB,
978 	.properties	= twl4030_charger_props,
979 	.num_properties	= ARRAY_SIZE(twl4030_charger_props),
980 	.get_property	= twl4030_bci_get_property,
981 };
982 
983 static int twl4030_bci_probe(struct platform_device *pdev)
984 {
985 	struct twl4030_bci *bci;
986 	const struct twl4030_bci_platform_data *pdata = pdev->dev.platform_data;
987 	int ret;
988 	u32 reg;
989 
990 	bci = devm_kzalloc(&pdev->dev, sizeof(*bci), GFP_KERNEL);
991 	if (bci == NULL)
992 		return -ENOMEM;
993 
994 	if (!pdata)
995 		pdata = twl4030_bci_parse_dt(&pdev->dev);
996 
997 	bci->ichg_eoc = 80100; /* Stop charging when current drops to here */
998 	bci->ichg_lo = 241000; /* Low threshold */
999 	bci->ichg_hi = 500000; /* High threshold */
1000 	bci->ac_cur = 500000; /* 500mA */
1001 	if (allow_usb)
1002 		bci->usb_cur_target = 500000;  /* 500mA */
1003 	else
1004 		bci->usb_cur_target = 100000;  /* 100mA */
1005 	bci->usb_mode = CHARGE_AUTO;
1006 	bci->ac_mode = CHARGE_AUTO;
1007 
1008 	bci->dev = &pdev->dev;
1009 	bci->irq_chg = platform_get_irq(pdev, 0);
1010 	bci->irq_bci = platform_get_irq(pdev, 1);
1011 
1012 	/* Only proceed further *IF* battery is physically present */
1013 	ret = twl4030_is_battery_present(bci);
1014 	if  (ret) {
1015 		dev_crit(&pdev->dev, "Battery was not detected:%d\n", ret);
1016 		return ret;
1017 	}
1018 
1019 	platform_set_drvdata(pdev, bci);
1020 
1021 	bci->ac = devm_power_supply_register(&pdev->dev, &twl4030_bci_ac_desc,
1022 					     NULL);
1023 	if (IS_ERR(bci->ac)) {
1024 		ret = PTR_ERR(bci->ac);
1025 		dev_err(&pdev->dev, "failed to register ac: %d\n", ret);
1026 		return ret;
1027 	}
1028 
1029 	bci->usb = devm_power_supply_register(&pdev->dev, &twl4030_bci_usb_desc,
1030 					      NULL);
1031 	if (IS_ERR(bci->usb)) {
1032 		ret = PTR_ERR(bci->usb);
1033 		dev_err(&pdev->dev, "failed to register usb: %d\n", ret);
1034 		return ret;
1035 	}
1036 
1037 	ret = devm_request_threaded_irq(&pdev->dev, bci->irq_chg, NULL,
1038 			twl4030_charger_interrupt, IRQF_ONESHOT, pdev->name,
1039 			bci);
1040 	if (ret < 0) {
1041 		dev_err(&pdev->dev, "could not request irq %d, status %d\n",
1042 			bci->irq_chg, ret);
1043 		return ret;
1044 	}
1045 
1046 	ret = devm_request_threaded_irq(&pdev->dev, bci->irq_bci, NULL,
1047 			twl4030_bci_interrupt, IRQF_ONESHOT, pdev->name, bci);
1048 	if (ret < 0) {
1049 		dev_err(&pdev->dev, "could not request irq %d, status %d\n",
1050 			bci->irq_bci, ret);
1051 		return ret;
1052 	}
1053 
1054 	bci->channel_vac = iio_channel_get(&pdev->dev, "vac");
1055 	if (IS_ERR(bci->channel_vac)) {
1056 		bci->channel_vac = NULL;
1057 		dev_warn(&pdev->dev, "could not request vac iio channel");
1058 	}
1059 
1060 	INIT_WORK(&bci->work, twl4030_bci_usb_work);
1061 	INIT_DELAYED_WORK(&bci->current_worker, twl4030_current_worker);
1062 
1063 	bci->usb_nb.notifier_call = twl4030_bci_usb_ncb;
1064 	if (bci->dev->of_node) {
1065 		struct device_node *phynode;
1066 
1067 		phynode = of_find_compatible_node(bci->dev->of_node->parent,
1068 						  NULL, "ti,twl4030-usb");
1069 		if (phynode)
1070 			bci->transceiver = devm_usb_get_phy_by_node(
1071 				bci->dev, phynode, &bci->usb_nb);
1072 	}
1073 
1074 	/* Enable interrupts now. */
1075 	reg = ~(u32)(TWL4030_ICHGLOW | TWL4030_ICHGEOC | TWL4030_TBATOR2 |
1076 		TWL4030_TBATOR1 | TWL4030_BATSTS);
1077 	ret = twl_i2c_write_u8(TWL4030_MODULE_INTERRUPTS, reg,
1078 			       TWL4030_INTERRUPTS_BCIIMR1A);
1079 	if (ret < 0) {
1080 		dev_err(&pdev->dev, "failed to unmask interrupts: %d\n", ret);
1081 		goto fail;
1082 	}
1083 
1084 	reg = ~(u32)(TWL4030_VBATOV | TWL4030_VBUSOV | TWL4030_ACCHGOV);
1085 	ret = twl_i2c_write_u8(TWL4030_MODULE_INTERRUPTS, reg,
1086 			       TWL4030_INTERRUPTS_BCIIMR2A);
1087 	if (ret < 0)
1088 		dev_warn(&pdev->dev, "failed to unmask interrupts: %d\n", ret);
1089 
1090 	twl4030_charger_update_current(bci);
1091 	if (device_create_file(&bci->usb->dev, &dev_attr_max_current))
1092 		dev_warn(&pdev->dev, "could not create sysfs file\n");
1093 	if (device_create_file(&bci->usb->dev, &dev_attr_mode))
1094 		dev_warn(&pdev->dev, "could not create sysfs file\n");
1095 	if (device_create_file(&bci->ac->dev, &dev_attr_mode))
1096 		dev_warn(&pdev->dev, "could not create sysfs file\n");
1097 	if (device_create_file(&bci->ac->dev, &dev_attr_max_current))
1098 		dev_warn(&pdev->dev, "could not create sysfs file\n");
1099 
1100 	twl4030_charger_enable_ac(bci, true);
1101 	if (!IS_ERR_OR_NULL(bci->transceiver))
1102 		twl4030_bci_usb_ncb(&bci->usb_nb,
1103 				    bci->transceiver->last_event,
1104 				    NULL);
1105 	else
1106 		twl4030_charger_enable_usb(bci, false);
1107 	if (pdata)
1108 		twl4030_charger_enable_backup(pdata->bb_uvolt,
1109 					      pdata->bb_uamp);
1110 	else
1111 		twl4030_charger_enable_backup(0, 0);
1112 
1113 	return 0;
1114 fail:
1115 	iio_channel_release(bci->channel_vac);
1116 
1117 	return ret;
1118 }
1119 
1120 static int __exit twl4030_bci_remove(struct platform_device *pdev)
1121 {
1122 	struct twl4030_bci *bci = platform_get_drvdata(pdev);
1123 
1124 	twl4030_charger_enable_ac(bci, false);
1125 	twl4030_charger_enable_usb(bci, false);
1126 	twl4030_charger_enable_backup(0, 0);
1127 
1128 	iio_channel_release(bci->channel_vac);
1129 
1130 	device_remove_file(&bci->usb->dev, &dev_attr_max_current);
1131 	device_remove_file(&bci->usb->dev, &dev_attr_mode);
1132 	device_remove_file(&bci->ac->dev, &dev_attr_max_current);
1133 	device_remove_file(&bci->ac->dev, &dev_attr_mode);
1134 	/* mask interrupts */
1135 	twl_i2c_write_u8(TWL4030_MODULE_INTERRUPTS, 0xff,
1136 			 TWL4030_INTERRUPTS_BCIIMR1A);
1137 	twl_i2c_write_u8(TWL4030_MODULE_INTERRUPTS, 0xff,
1138 			 TWL4030_INTERRUPTS_BCIIMR2A);
1139 
1140 	return 0;
1141 }
1142 
1143 static const struct of_device_id twl_bci_of_match[] = {
1144 	{.compatible = "ti,twl4030-bci", },
1145 	{ }
1146 };
1147 MODULE_DEVICE_TABLE(of, twl_bci_of_match);
1148 
1149 static struct platform_driver twl4030_bci_driver = {
1150 	.probe = twl4030_bci_probe,
1151 	.driver	= {
1152 		.name	= "twl4030_bci",
1153 		.of_match_table = of_match_ptr(twl_bci_of_match),
1154 	},
1155 	.remove	= __exit_p(twl4030_bci_remove),
1156 };
1157 module_platform_driver(twl4030_bci_driver);
1158 
1159 MODULE_AUTHOR("Gražvydas Ignotas");
1160 MODULE_DESCRIPTION("TWL4030 Battery Charger Interface driver");
1161 MODULE_LICENSE("GPL");
1162 MODULE_ALIAS("platform:twl4030_bci");
1163