1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Battery driver for wm8350 PMIC
4  *
5  * Copyright 2007, 2008 Wolfson Microelectronics PLC.
6  *
7  * Based on OLPC Battery Driver
8  *
9  * Copyright 2006  David Woodhouse <dwmw2@infradead.org>
10  */
11 
12 #include <linux/module.h>
13 #include <linux/err.h>
14 #include <linux/platform_device.h>
15 #include <linux/power_supply.h>
16 #include <linux/mfd/wm8350/supply.h>
17 #include <linux/mfd/wm8350/core.h>
18 #include <linux/mfd/wm8350/comparator.h>
19 
20 static int wm8350_read_battery_uvolts(struct wm8350 *wm8350)
21 {
22 	return wm8350_read_auxadc(wm8350, WM8350_AUXADC_BATT, 0, 0)
23 		* WM8350_AUX_COEFF;
24 }
25 
26 static int wm8350_read_line_uvolts(struct wm8350 *wm8350)
27 {
28 	return wm8350_read_auxadc(wm8350, WM8350_AUXADC_LINE, 0, 0)
29 		* WM8350_AUX_COEFF;
30 }
31 
32 static int wm8350_read_usb_uvolts(struct wm8350 *wm8350)
33 {
34 	return wm8350_read_auxadc(wm8350, WM8350_AUXADC_USB, 0, 0)
35 		* WM8350_AUX_COEFF;
36 }
37 
38 #define WM8350_BATT_SUPPLY	1
39 #define WM8350_USB_SUPPLY	2
40 #define WM8350_LINE_SUPPLY	4
41 
42 static inline int wm8350_charge_time_min(struct wm8350 *wm8350, int min)
43 {
44 	if (!wm8350->power.rev_g_coeff)
45 		return (((min - 30) / 15) & 0xf) << 8;
46 	else
47 		return (((min - 30) / 30) & 0xf) << 8;
48 }
49 
50 static int wm8350_get_supplies(struct wm8350 *wm8350)
51 {
52 	u16 sm, ov, co, chrg;
53 	int supplies = 0;
54 
55 	sm = wm8350_reg_read(wm8350, WM8350_STATE_MACHINE_STATUS);
56 	ov = wm8350_reg_read(wm8350, WM8350_MISC_OVERRIDES);
57 	co = wm8350_reg_read(wm8350, WM8350_COMPARATOR_OVERRIDES);
58 	chrg = wm8350_reg_read(wm8350, WM8350_BATTERY_CHARGER_CONTROL_2);
59 
60 	/* USB_SM */
61 	sm = (sm & WM8350_USB_SM_MASK) >> WM8350_USB_SM_SHIFT;
62 
63 	/* CHG_ISEL */
64 	chrg &= WM8350_CHG_ISEL_MASK;
65 
66 	/* If the USB state machine is active then we're using that with or
67 	 * without battery, otherwise check for wall supply */
68 	if (((sm == WM8350_USB_SM_100_SLV) ||
69 	     (sm == WM8350_USB_SM_500_SLV) ||
70 	     (sm == WM8350_USB_SM_STDBY_SLV))
71 	    && !(ov & WM8350_USB_LIMIT_OVRDE))
72 		supplies = WM8350_USB_SUPPLY;
73 	else if (((sm == WM8350_USB_SM_100_SLV) ||
74 		  (sm == WM8350_USB_SM_500_SLV) ||
75 		  (sm == WM8350_USB_SM_STDBY_SLV))
76 		 && (ov & WM8350_USB_LIMIT_OVRDE) && (chrg == 0))
77 		supplies = WM8350_USB_SUPPLY | WM8350_BATT_SUPPLY;
78 	else if (co & WM8350_WALL_FB_OVRDE)
79 		supplies = WM8350_LINE_SUPPLY;
80 	else
81 		supplies = WM8350_BATT_SUPPLY;
82 
83 	return supplies;
84 }
85 
86 static int wm8350_charger_config(struct wm8350 *wm8350,
87 				 struct wm8350_charger_policy *policy)
88 {
89 	u16 reg, eoc_mA, fast_limit_mA;
90 
91 	if (!policy) {
92 		dev_warn(wm8350->dev,
93 			 "No charger policy, charger not configured.\n");
94 		return -EINVAL;
95 	}
96 
97 	/* make sure USB fast charge current is not > 500mA */
98 	if (policy->fast_limit_USB_mA > 500) {
99 		dev_err(wm8350->dev, "USB fast charge > 500mA\n");
100 		return -EINVAL;
101 	}
102 
103 	eoc_mA = WM8350_CHG_EOC_mA(policy->eoc_mA);
104 
105 	wm8350_reg_unlock(wm8350);
106 
107 	reg = wm8350_reg_read(wm8350, WM8350_BATTERY_CHARGER_CONTROL_1)
108 		& WM8350_CHG_ENA_R168;
109 	wm8350_reg_write(wm8350, WM8350_BATTERY_CHARGER_CONTROL_1,
110 			 reg | eoc_mA | policy->trickle_start_mV |
111 			 WM8350_CHG_TRICKLE_TEMP_CHOKE |
112 			 WM8350_CHG_TRICKLE_USB_CHOKE |
113 			 WM8350_CHG_FAST_USB_THROTTLE);
114 
115 	if (wm8350_get_supplies(wm8350) & WM8350_USB_SUPPLY) {
116 		fast_limit_mA =
117 			WM8350_CHG_FAST_LIMIT_mA(policy->fast_limit_USB_mA);
118 		wm8350_reg_write(wm8350, WM8350_BATTERY_CHARGER_CONTROL_2,
119 			    policy->charge_mV | policy->trickle_charge_USB_mA |
120 			    fast_limit_mA | wm8350_charge_time_min(wm8350,
121 						policy->charge_timeout));
122 
123 	} else {
124 		fast_limit_mA =
125 			WM8350_CHG_FAST_LIMIT_mA(policy->fast_limit_mA);
126 		wm8350_reg_write(wm8350, WM8350_BATTERY_CHARGER_CONTROL_2,
127 			    policy->charge_mV | policy->trickle_charge_mA |
128 			    fast_limit_mA | wm8350_charge_time_min(wm8350,
129 						policy->charge_timeout));
130 	}
131 
132 	wm8350_reg_lock(wm8350);
133 	return 0;
134 }
135 
136 static int wm8350_batt_status(struct wm8350 *wm8350)
137 {
138 	u16 state;
139 
140 	state = wm8350_reg_read(wm8350, WM8350_BATTERY_CHARGER_CONTROL_2);
141 	state &= WM8350_CHG_STS_MASK;
142 
143 	switch (state) {
144 	case WM8350_CHG_STS_OFF:
145 		return POWER_SUPPLY_STATUS_DISCHARGING;
146 
147 	case WM8350_CHG_STS_TRICKLE:
148 	case WM8350_CHG_STS_FAST:
149 		return POWER_SUPPLY_STATUS_CHARGING;
150 
151 	default:
152 		return POWER_SUPPLY_STATUS_UNKNOWN;
153 	}
154 }
155 
156 static ssize_t charger_state_show(struct device *dev,
157 				 struct device_attribute *attr, char *buf)
158 {
159 	struct wm8350 *wm8350 = dev_get_drvdata(dev);
160 	char *charge;
161 	int state;
162 
163 	state = wm8350_reg_read(wm8350, WM8350_BATTERY_CHARGER_CONTROL_2) &
164 	    WM8350_CHG_STS_MASK;
165 	switch (state) {
166 	case WM8350_CHG_STS_OFF:
167 		charge = "Charger Off";
168 		break;
169 	case WM8350_CHG_STS_TRICKLE:
170 		charge = "Trickle Charging";
171 		break;
172 	case WM8350_CHG_STS_FAST:
173 		charge = "Fast Charging";
174 		break;
175 	default:
176 		return 0;
177 	}
178 
179 	return sprintf(buf, "%s\n", charge);
180 }
181 
182 static DEVICE_ATTR_RO(charger_state);
183 
184 static irqreturn_t wm8350_charger_handler(int irq, void *data)
185 {
186 	struct wm8350 *wm8350 = data;
187 	struct wm8350_power *power = &wm8350->power;
188 	struct wm8350_charger_policy *policy = power->policy;
189 
190 	switch (irq - wm8350->irq_base) {
191 	case WM8350_IRQ_CHG_BAT_FAIL:
192 		dev_err(wm8350->dev, "battery failed\n");
193 		break;
194 	case WM8350_IRQ_CHG_TO:
195 		dev_err(wm8350->dev, "charger timeout\n");
196 		power_supply_changed(power->battery);
197 		break;
198 
199 	case WM8350_IRQ_CHG_BAT_HOT:
200 	case WM8350_IRQ_CHG_BAT_COLD:
201 	case WM8350_IRQ_CHG_START:
202 	case WM8350_IRQ_CHG_END:
203 		power_supply_changed(power->battery);
204 		break;
205 
206 	case WM8350_IRQ_CHG_FAST_RDY:
207 		dev_dbg(wm8350->dev, "fast charger ready\n");
208 		wm8350_charger_config(wm8350, policy);
209 		wm8350_reg_unlock(wm8350);
210 		wm8350_set_bits(wm8350, WM8350_BATTERY_CHARGER_CONTROL_1,
211 				WM8350_CHG_FAST);
212 		wm8350_reg_lock(wm8350);
213 		break;
214 
215 	case WM8350_IRQ_CHG_VBATT_LT_3P9:
216 		dev_warn(wm8350->dev, "battery < 3.9V\n");
217 		break;
218 	case WM8350_IRQ_CHG_VBATT_LT_3P1:
219 		dev_warn(wm8350->dev, "battery < 3.1V\n");
220 		break;
221 	case WM8350_IRQ_CHG_VBATT_LT_2P85:
222 		dev_warn(wm8350->dev, "battery < 2.85V\n");
223 		break;
224 
225 		/* Supply change.  We will overnotify but it should do
226 		 * no harm. */
227 	case WM8350_IRQ_EXT_USB_FB:
228 	case WM8350_IRQ_EXT_WALL_FB:
229 		wm8350_charger_config(wm8350, policy);
230 		/* Fall through */
231 	case WM8350_IRQ_EXT_BAT_FB:
232 		power_supply_changed(power->battery);
233 		power_supply_changed(power->usb);
234 		power_supply_changed(power->ac);
235 		break;
236 
237 	default:
238 		dev_err(wm8350->dev, "Unknown interrupt %d\n", irq);
239 	}
240 
241 	return IRQ_HANDLED;
242 }
243 
244 /*********************************************************************
245  *		AC Power
246  *********************************************************************/
247 static int wm8350_ac_get_prop(struct power_supply *psy,
248 			      enum power_supply_property psp,
249 			      union power_supply_propval *val)
250 {
251 	struct wm8350 *wm8350 = dev_get_drvdata(psy->dev.parent);
252 	int ret = 0;
253 
254 	switch (psp) {
255 	case POWER_SUPPLY_PROP_ONLINE:
256 		val->intval = !!(wm8350_get_supplies(wm8350) &
257 				 WM8350_LINE_SUPPLY);
258 		break;
259 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
260 		val->intval = wm8350_read_line_uvolts(wm8350);
261 		break;
262 	default:
263 		ret = -EINVAL;
264 		break;
265 	}
266 	return ret;
267 }
268 
269 static enum power_supply_property wm8350_ac_props[] = {
270 	POWER_SUPPLY_PROP_ONLINE,
271 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
272 };
273 
274 /*********************************************************************
275  *		USB Power
276  *********************************************************************/
277 static int wm8350_usb_get_prop(struct power_supply *psy,
278 			       enum power_supply_property psp,
279 			       union power_supply_propval *val)
280 {
281 	struct wm8350 *wm8350 = dev_get_drvdata(psy->dev.parent);
282 	int ret = 0;
283 
284 	switch (psp) {
285 	case POWER_SUPPLY_PROP_ONLINE:
286 		val->intval = !!(wm8350_get_supplies(wm8350) &
287 				 WM8350_USB_SUPPLY);
288 		break;
289 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
290 		val->intval = wm8350_read_usb_uvolts(wm8350);
291 		break;
292 	default:
293 		ret = -EINVAL;
294 		break;
295 	}
296 	return ret;
297 }
298 
299 static enum power_supply_property wm8350_usb_props[] = {
300 	POWER_SUPPLY_PROP_ONLINE,
301 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
302 };
303 
304 /*********************************************************************
305  *		Battery properties
306  *********************************************************************/
307 
308 static int wm8350_bat_check_health(struct wm8350 *wm8350)
309 {
310 	u16 reg;
311 
312 	if (wm8350_read_battery_uvolts(wm8350) < 2850000)
313 		return POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
314 
315 	reg = wm8350_reg_read(wm8350, WM8350_CHARGER_OVERRIDES);
316 	if (reg & WM8350_CHG_BATT_HOT_OVRDE)
317 		return POWER_SUPPLY_HEALTH_OVERHEAT;
318 
319 	if (reg & WM8350_CHG_BATT_COLD_OVRDE)
320 		return POWER_SUPPLY_HEALTH_COLD;
321 
322 	return POWER_SUPPLY_HEALTH_GOOD;
323 }
324 
325 static int wm8350_bat_get_charge_type(struct wm8350 *wm8350)
326 {
327 	int state;
328 
329 	state = wm8350_reg_read(wm8350, WM8350_BATTERY_CHARGER_CONTROL_2) &
330 	    WM8350_CHG_STS_MASK;
331 	switch (state) {
332 	case WM8350_CHG_STS_OFF:
333 		return POWER_SUPPLY_CHARGE_TYPE_NONE;
334 	case WM8350_CHG_STS_TRICKLE:
335 		return POWER_SUPPLY_CHARGE_TYPE_TRICKLE;
336 	case WM8350_CHG_STS_FAST:
337 		return POWER_SUPPLY_CHARGE_TYPE_FAST;
338 	default:
339 		return POWER_SUPPLY_CHARGE_TYPE_UNKNOWN;
340 	}
341 }
342 
343 static int wm8350_bat_get_property(struct power_supply *psy,
344 				   enum power_supply_property psp,
345 				   union power_supply_propval *val)
346 {
347 	struct wm8350 *wm8350 = dev_get_drvdata(psy->dev.parent);
348 	int ret = 0;
349 
350 	switch (psp) {
351 	case POWER_SUPPLY_PROP_STATUS:
352 		val->intval = wm8350_batt_status(wm8350);
353 		break;
354 	case POWER_SUPPLY_PROP_ONLINE:
355 		val->intval = !!(wm8350_get_supplies(wm8350) &
356 				 WM8350_BATT_SUPPLY);
357 		break;
358 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
359 		val->intval = wm8350_read_battery_uvolts(wm8350);
360 		break;
361 	case POWER_SUPPLY_PROP_HEALTH:
362 		val->intval = wm8350_bat_check_health(wm8350);
363 		break;
364 	case POWER_SUPPLY_PROP_CHARGE_TYPE:
365 		val->intval = wm8350_bat_get_charge_type(wm8350);
366 		break;
367 	default:
368 		ret = -EINVAL;
369 		break;
370 	}
371 
372 	return ret;
373 }
374 
375 static enum power_supply_property wm8350_bat_props[] = {
376 	POWER_SUPPLY_PROP_STATUS,
377 	POWER_SUPPLY_PROP_ONLINE,
378 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
379 	POWER_SUPPLY_PROP_HEALTH,
380 	POWER_SUPPLY_PROP_CHARGE_TYPE,
381 };
382 
383 static const struct power_supply_desc wm8350_ac_desc = {
384 	.name		= "wm8350-ac",
385 	.type		= POWER_SUPPLY_TYPE_MAINS,
386 	.properties	= wm8350_ac_props,
387 	.num_properties	= ARRAY_SIZE(wm8350_ac_props),
388 	.get_property	= wm8350_ac_get_prop,
389 };
390 
391 static const struct power_supply_desc wm8350_battery_desc = {
392 	.name		= "wm8350-battery",
393 	.properties	= wm8350_bat_props,
394 	.num_properties	= ARRAY_SIZE(wm8350_bat_props),
395 	.get_property	= wm8350_bat_get_property,
396 	.use_for_apm	= 1,
397 };
398 
399 static const struct power_supply_desc wm8350_usb_desc = {
400 	.name		= "wm8350-usb",
401 	.type		= POWER_SUPPLY_TYPE_USB,
402 	.properties	= wm8350_usb_props,
403 	.num_properties	= ARRAY_SIZE(wm8350_usb_props),
404 	.get_property	= wm8350_usb_get_prop,
405 };
406 
407 /*********************************************************************
408  *		Initialisation
409  *********************************************************************/
410 
411 static void wm8350_init_charger(struct wm8350 *wm8350)
412 {
413 	/* register our interest in charger events */
414 	wm8350_register_irq(wm8350, WM8350_IRQ_CHG_BAT_HOT,
415 			    wm8350_charger_handler, 0, "Battery hot", wm8350);
416 	wm8350_register_irq(wm8350, WM8350_IRQ_CHG_BAT_COLD,
417 			    wm8350_charger_handler, 0, "Battery cold", wm8350);
418 	wm8350_register_irq(wm8350, WM8350_IRQ_CHG_BAT_FAIL,
419 			    wm8350_charger_handler, 0, "Battery fail", wm8350);
420 	wm8350_register_irq(wm8350, WM8350_IRQ_CHG_TO,
421 			    wm8350_charger_handler, 0,
422 			    "Charger timeout", wm8350);
423 	wm8350_register_irq(wm8350, WM8350_IRQ_CHG_END,
424 			    wm8350_charger_handler, 0,
425 			    "Charge end", wm8350);
426 	wm8350_register_irq(wm8350, WM8350_IRQ_CHG_START,
427 			    wm8350_charger_handler, 0,
428 			    "Charge start", wm8350);
429 	wm8350_register_irq(wm8350, WM8350_IRQ_CHG_FAST_RDY,
430 			    wm8350_charger_handler, 0,
431 			    "Fast charge ready", wm8350);
432 	wm8350_register_irq(wm8350, WM8350_IRQ_CHG_VBATT_LT_3P9,
433 			    wm8350_charger_handler, 0,
434 			    "Battery <3.9V", wm8350);
435 	wm8350_register_irq(wm8350, WM8350_IRQ_CHG_VBATT_LT_3P1,
436 			    wm8350_charger_handler, 0,
437 			    "Battery <3.1V", wm8350);
438 	wm8350_register_irq(wm8350, WM8350_IRQ_CHG_VBATT_LT_2P85,
439 			    wm8350_charger_handler, 0,
440 			    "Battery <2.85V", wm8350);
441 
442 	/* and supply change events */
443 	wm8350_register_irq(wm8350, WM8350_IRQ_EXT_USB_FB,
444 			    wm8350_charger_handler, 0, "USB", wm8350);
445 	wm8350_register_irq(wm8350, WM8350_IRQ_EXT_WALL_FB,
446 			    wm8350_charger_handler, 0, "Wall", wm8350);
447 	wm8350_register_irq(wm8350, WM8350_IRQ_EXT_BAT_FB,
448 			    wm8350_charger_handler, 0, "Battery", wm8350);
449 }
450 
451 static void free_charger_irq(struct wm8350 *wm8350)
452 {
453 	wm8350_free_irq(wm8350, WM8350_IRQ_CHG_BAT_HOT, wm8350);
454 	wm8350_free_irq(wm8350, WM8350_IRQ_CHG_BAT_COLD, wm8350);
455 	wm8350_free_irq(wm8350, WM8350_IRQ_CHG_BAT_FAIL, wm8350);
456 	wm8350_free_irq(wm8350, WM8350_IRQ_CHG_TO, wm8350);
457 	wm8350_free_irq(wm8350, WM8350_IRQ_CHG_END, wm8350);
458 	wm8350_free_irq(wm8350, WM8350_IRQ_CHG_START, wm8350);
459 	wm8350_free_irq(wm8350, WM8350_IRQ_CHG_VBATT_LT_3P9, wm8350);
460 	wm8350_free_irq(wm8350, WM8350_IRQ_CHG_VBATT_LT_3P1, wm8350);
461 	wm8350_free_irq(wm8350, WM8350_IRQ_CHG_VBATT_LT_2P85, wm8350);
462 	wm8350_free_irq(wm8350, WM8350_IRQ_EXT_USB_FB, wm8350);
463 	wm8350_free_irq(wm8350, WM8350_IRQ_EXT_WALL_FB, wm8350);
464 	wm8350_free_irq(wm8350, WM8350_IRQ_EXT_BAT_FB, wm8350);
465 }
466 
467 static int wm8350_power_probe(struct platform_device *pdev)
468 {
469 	struct wm8350 *wm8350 = platform_get_drvdata(pdev);
470 	struct wm8350_power *power = &wm8350->power;
471 	struct wm8350_charger_policy *policy = power->policy;
472 	int ret;
473 
474 	power->ac = power_supply_register(&pdev->dev, &wm8350_ac_desc, NULL);
475 	if (IS_ERR(power->ac))
476 		return PTR_ERR(power->ac);
477 
478 	power->battery = power_supply_register(&pdev->dev, &wm8350_battery_desc,
479 					       NULL);
480 	if (IS_ERR(power->battery)) {
481 		ret = PTR_ERR(power->battery);
482 		goto battery_failed;
483 	}
484 
485 	power->usb = power_supply_register(&pdev->dev, &wm8350_usb_desc, NULL);
486 	if (IS_ERR(power->usb)) {
487 		ret = PTR_ERR(power->usb);
488 		goto usb_failed;
489 	}
490 
491 	ret = device_create_file(&pdev->dev, &dev_attr_charger_state);
492 	if (ret < 0)
493 		dev_warn(wm8350->dev, "failed to add charge sysfs: %d\n", ret);
494 	ret = 0;
495 
496 	wm8350_init_charger(wm8350);
497 	if (wm8350_charger_config(wm8350, policy) == 0) {
498 		wm8350_reg_unlock(wm8350);
499 		wm8350_set_bits(wm8350, WM8350_POWER_MGMT_5, WM8350_CHG_ENA);
500 		wm8350_reg_lock(wm8350);
501 	}
502 
503 	return ret;
504 
505 usb_failed:
506 	power_supply_unregister(power->battery);
507 battery_failed:
508 	power_supply_unregister(power->ac);
509 
510 	return ret;
511 }
512 
513 static int wm8350_power_remove(struct platform_device *pdev)
514 {
515 	struct wm8350 *wm8350 = platform_get_drvdata(pdev);
516 	struct wm8350_power *power = &wm8350->power;
517 
518 	free_charger_irq(wm8350);
519 	device_remove_file(&pdev->dev, &dev_attr_charger_state);
520 	power_supply_unregister(power->battery);
521 	power_supply_unregister(power->ac);
522 	power_supply_unregister(power->usb);
523 	return 0;
524 }
525 
526 static struct platform_driver wm8350_power_driver = {
527 	.probe = wm8350_power_probe,
528 	.remove = wm8350_power_remove,
529 	.driver = {
530 		.name = "wm8350-power",
531 	},
532 };
533 
534 module_platform_driver(wm8350_power_driver);
535 
536 MODULE_LICENSE("GPL");
537 MODULE_DESCRIPTION("Power supply driver for WM8350");
538 MODULE_ALIAS("platform:wm8350-power");
539