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1 /*
2  * Battery driver for wm8350 PMIC
3  *
4  * Copyright 2007, 2008 Wolfson Microelectronics PLC.
5  *
6  * Based on OLPC Battery Driver
7  *
8  * Copyright 2006  David Woodhouse <dwmw2@infradead.org>
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License version 2 as
12  * published by the Free Software Foundation.
13  */
14 
15 #include <linux/module.h>
16 #include <linux/err.h>
17 #include <linux/platform_device.h>
18 #include <linux/power_supply.h>
19 #include <linux/mfd/wm8350/supply.h>
20 #include <linux/mfd/wm8350/core.h>
21 #include <linux/mfd/wm8350/comparator.h>
22 
wm8350_read_battery_uvolts(struct wm8350 * wm8350)23 static int wm8350_read_battery_uvolts(struct wm8350 *wm8350)
24 {
25 	return wm8350_read_auxadc(wm8350, WM8350_AUXADC_BATT, 0, 0)
26 		* WM8350_AUX_COEFF;
27 }
28 
wm8350_read_line_uvolts(struct wm8350 * wm8350)29 static int wm8350_read_line_uvolts(struct wm8350 *wm8350)
30 {
31 	return wm8350_read_auxadc(wm8350, WM8350_AUXADC_LINE, 0, 0)
32 		* WM8350_AUX_COEFF;
33 }
34 
wm8350_read_usb_uvolts(struct wm8350 * wm8350)35 static int wm8350_read_usb_uvolts(struct wm8350 *wm8350)
36 {
37 	return wm8350_read_auxadc(wm8350, WM8350_AUXADC_USB, 0, 0)
38 		* WM8350_AUX_COEFF;
39 }
40 
41 #define WM8350_BATT_SUPPLY	1
42 #define WM8350_USB_SUPPLY	2
43 #define WM8350_LINE_SUPPLY	4
44 
wm8350_charge_time_min(struct wm8350 * wm8350,int min)45 static inline int wm8350_charge_time_min(struct wm8350 *wm8350, int min)
46 {
47 	if (!wm8350->power.rev_g_coeff)
48 		return (((min - 30) / 15) & 0xf) << 8;
49 	else
50 		return (((min - 30) / 30) & 0xf) << 8;
51 }
52 
wm8350_get_supplies(struct wm8350 * wm8350)53 static int wm8350_get_supplies(struct wm8350 *wm8350)
54 {
55 	u16 sm, ov, co, chrg;
56 	int supplies = 0;
57 
58 	sm = wm8350_reg_read(wm8350, WM8350_STATE_MACHINE_STATUS);
59 	ov = wm8350_reg_read(wm8350, WM8350_MISC_OVERRIDES);
60 	co = wm8350_reg_read(wm8350, WM8350_COMPARATOR_OVERRIDES);
61 	chrg = wm8350_reg_read(wm8350, WM8350_BATTERY_CHARGER_CONTROL_2);
62 
63 	/* USB_SM */
64 	sm = (sm & WM8350_USB_SM_MASK) >> WM8350_USB_SM_SHIFT;
65 
66 	/* CHG_ISEL */
67 	chrg &= WM8350_CHG_ISEL_MASK;
68 
69 	/* If the USB state machine is active then we're using that with or
70 	 * without battery, otherwise check for wall supply */
71 	if (((sm == WM8350_USB_SM_100_SLV) ||
72 	     (sm == WM8350_USB_SM_500_SLV) ||
73 	     (sm == WM8350_USB_SM_STDBY_SLV))
74 	    && !(ov & WM8350_USB_LIMIT_OVRDE))
75 		supplies = WM8350_USB_SUPPLY;
76 	else if (((sm == WM8350_USB_SM_100_SLV) ||
77 		  (sm == WM8350_USB_SM_500_SLV) ||
78 		  (sm == WM8350_USB_SM_STDBY_SLV))
79 		 && (ov & WM8350_USB_LIMIT_OVRDE) && (chrg == 0))
80 		supplies = WM8350_USB_SUPPLY | WM8350_BATT_SUPPLY;
81 	else if (co & WM8350_WALL_FB_OVRDE)
82 		supplies = WM8350_LINE_SUPPLY;
83 	else
84 		supplies = WM8350_BATT_SUPPLY;
85 
86 	return supplies;
87 }
88 
wm8350_charger_config(struct wm8350 * wm8350,struct wm8350_charger_policy * policy)89 static int wm8350_charger_config(struct wm8350 *wm8350,
90 				 struct wm8350_charger_policy *policy)
91 {
92 	u16 reg, eoc_mA, fast_limit_mA;
93 
94 	if (!policy) {
95 		dev_warn(wm8350->dev,
96 			 "No charger policy, charger not configured.\n");
97 		return -EINVAL;
98 	}
99 
100 	/* make sure USB fast charge current is not > 500mA */
101 	if (policy->fast_limit_USB_mA > 500) {
102 		dev_err(wm8350->dev, "USB fast charge > 500mA\n");
103 		return -EINVAL;
104 	}
105 
106 	eoc_mA = WM8350_CHG_EOC_mA(policy->eoc_mA);
107 
108 	wm8350_reg_unlock(wm8350);
109 
110 	reg = wm8350_reg_read(wm8350, WM8350_BATTERY_CHARGER_CONTROL_1)
111 		& WM8350_CHG_ENA_R168;
112 	wm8350_reg_write(wm8350, WM8350_BATTERY_CHARGER_CONTROL_1,
113 			 reg | eoc_mA | policy->trickle_start_mV |
114 			 WM8350_CHG_TRICKLE_TEMP_CHOKE |
115 			 WM8350_CHG_TRICKLE_USB_CHOKE |
116 			 WM8350_CHG_FAST_USB_THROTTLE);
117 
118 	if (wm8350_get_supplies(wm8350) & WM8350_USB_SUPPLY) {
119 		fast_limit_mA =
120 			WM8350_CHG_FAST_LIMIT_mA(policy->fast_limit_USB_mA);
121 		wm8350_reg_write(wm8350, WM8350_BATTERY_CHARGER_CONTROL_2,
122 			    policy->charge_mV | policy->trickle_charge_USB_mA |
123 			    fast_limit_mA | wm8350_charge_time_min(wm8350,
124 						policy->charge_timeout));
125 
126 	} else {
127 		fast_limit_mA =
128 			WM8350_CHG_FAST_LIMIT_mA(policy->fast_limit_mA);
129 		wm8350_reg_write(wm8350, WM8350_BATTERY_CHARGER_CONTROL_2,
130 			    policy->charge_mV | policy->trickle_charge_mA |
131 			    fast_limit_mA | wm8350_charge_time_min(wm8350,
132 						policy->charge_timeout));
133 	}
134 
135 	wm8350_reg_lock(wm8350);
136 	return 0;
137 }
138 
wm8350_batt_status(struct wm8350 * wm8350)139 static int wm8350_batt_status(struct wm8350 *wm8350)
140 {
141 	u16 state;
142 
143 	state = wm8350_reg_read(wm8350, WM8350_BATTERY_CHARGER_CONTROL_2);
144 	state &= WM8350_CHG_STS_MASK;
145 
146 	switch (state) {
147 	case WM8350_CHG_STS_OFF:
148 		return POWER_SUPPLY_STATUS_DISCHARGING;
149 
150 	case WM8350_CHG_STS_TRICKLE:
151 	case WM8350_CHG_STS_FAST:
152 		return POWER_SUPPLY_STATUS_CHARGING;
153 
154 	default:
155 		return POWER_SUPPLY_STATUS_UNKNOWN;
156 	}
157 }
158 
charger_state_show(struct device * dev,struct device_attribute * attr,char * buf)159 static ssize_t charger_state_show(struct device *dev,
160 				 struct device_attribute *attr, char *buf)
161 {
162 	struct wm8350 *wm8350 = dev_get_drvdata(dev);
163 	char *charge;
164 	int state;
165 
166 	state = wm8350_reg_read(wm8350, WM8350_BATTERY_CHARGER_CONTROL_2) &
167 	    WM8350_CHG_STS_MASK;
168 	switch (state) {
169 	case WM8350_CHG_STS_OFF:
170 		charge = "Charger Off";
171 		break;
172 	case WM8350_CHG_STS_TRICKLE:
173 		charge = "Trickle Charging";
174 		break;
175 	case WM8350_CHG_STS_FAST:
176 		charge = "Fast Charging";
177 		break;
178 	default:
179 		return 0;
180 	}
181 
182 	return sprintf(buf, "%s\n", charge);
183 }
184 
185 static DEVICE_ATTR(charger_state, 0444, charger_state_show, NULL);
186 
wm8350_charger_handler(int irq,void * data)187 static irqreturn_t wm8350_charger_handler(int irq, void *data)
188 {
189 	struct wm8350 *wm8350 = data;
190 	struct wm8350_power *power = &wm8350->power;
191 	struct wm8350_charger_policy *policy = power->policy;
192 
193 	switch (irq - wm8350->irq_base) {
194 	case WM8350_IRQ_CHG_BAT_FAIL:
195 		dev_err(wm8350->dev, "battery failed\n");
196 		break;
197 	case WM8350_IRQ_CHG_TO:
198 		dev_err(wm8350->dev, "charger timeout\n");
199 		power_supply_changed(&power->battery);
200 		break;
201 
202 	case WM8350_IRQ_CHG_BAT_HOT:
203 	case WM8350_IRQ_CHG_BAT_COLD:
204 	case WM8350_IRQ_CHG_START:
205 	case WM8350_IRQ_CHG_END:
206 		power_supply_changed(&power->battery);
207 		break;
208 
209 	case WM8350_IRQ_CHG_FAST_RDY:
210 		dev_dbg(wm8350->dev, "fast charger ready\n");
211 		wm8350_charger_config(wm8350, policy);
212 		wm8350_reg_unlock(wm8350);
213 		wm8350_set_bits(wm8350, WM8350_BATTERY_CHARGER_CONTROL_1,
214 				WM8350_CHG_FAST);
215 		wm8350_reg_lock(wm8350);
216 		break;
217 
218 	case WM8350_IRQ_CHG_VBATT_LT_3P9:
219 		dev_warn(wm8350->dev, "battery < 3.9V\n");
220 		break;
221 	case WM8350_IRQ_CHG_VBATT_LT_3P1:
222 		dev_warn(wm8350->dev, "battery < 3.1V\n");
223 		break;
224 	case WM8350_IRQ_CHG_VBATT_LT_2P85:
225 		dev_warn(wm8350->dev, "battery < 2.85V\n");
226 		break;
227 
228 		/* Supply change.  We will overnotify but it should do
229 		 * no harm. */
230 	case WM8350_IRQ_EXT_USB_FB:
231 	case WM8350_IRQ_EXT_WALL_FB:
232 		wm8350_charger_config(wm8350, policy);
233 	case WM8350_IRQ_EXT_BAT_FB:   /* Fall through */
234 		power_supply_changed(&power->battery);
235 		power_supply_changed(&power->usb);
236 		power_supply_changed(&power->ac);
237 		break;
238 
239 	default:
240 		dev_err(wm8350->dev, "Unknown interrupt %d\n", irq);
241 	}
242 
243 	return IRQ_HANDLED;
244 }
245 
246 /*********************************************************************
247  *		AC Power
248  *********************************************************************/
wm8350_ac_get_prop(struct power_supply * psy,enum power_supply_property psp,union power_supply_propval * val)249 static int wm8350_ac_get_prop(struct power_supply *psy,
250 			      enum power_supply_property psp,
251 			      union power_supply_propval *val)
252 {
253 	struct wm8350 *wm8350 = dev_get_drvdata(psy->dev->parent);
254 	int ret = 0;
255 
256 	switch (psp) {
257 	case POWER_SUPPLY_PROP_ONLINE:
258 		val->intval = !!(wm8350_get_supplies(wm8350) &
259 				 WM8350_LINE_SUPPLY);
260 		break;
261 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
262 		val->intval = wm8350_read_line_uvolts(wm8350);
263 		break;
264 	default:
265 		ret = -EINVAL;
266 		break;
267 	}
268 	return ret;
269 }
270 
271 static enum power_supply_property wm8350_ac_props[] = {
272 	POWER_SUPPLY_PROP_ONLINE,
273 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
274 };
275 
276 /*********************************************************************
277  *		USB Power
278  *********************************************************************/
wm8350_usb_get_prop(struct power_supply * psy,enum power_supply_property psp,union power_supply_propval * val)279 static int wm8350_usb_get_prop(struct power_supply *psy,
280 			       enum power_supply_property psp,
281 			       union power_supply_propval *val)
282 {
283 	struct wm8350 *wm8350 = dev_get_drvdata(psy->dev->parent);
284 	int ret = 0;
285 
286 	switch (psp) {
287 	case POWER_SUPPLY_PROP_ONLINE:
288 		val->intval = !!(wm8350_get_supplies(wm8350) &
289 				 WM8350_USB_SUPPLY);
290 		break;
291 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
292 		val->intval = wm8350_read_usb_uvolts(wm8350);
293 		break;
294 	default:
295 		ret = -EINVAL;
296 		break;
297 	}
298 	return ret;
299 }
300 
301 static enum power_supply_property wm8350_usb_props[] = {
302 	POWER_SUPPLY_PROP_ONLINE,
303 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
304 };
305 
306 /*********************************************************************
307  *		Battery properties
308  *********************************************************************/
309 
wm8350_bat_check_health(struct wm8350 * wm8350)310 static int wm8350_bat_check_health(struct wm8350 *wm8350)
311 {
312 	u16 reg;
313 
314 	if (wm8350_read_battery_uvolts(wm8350) < 2850000)
315 		return POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
316 
317 	reg = wm8350_reg_read(wm8350, WM8350_CHARGER_OVERRIDES);
318 	if (reg & WM8350_CHG_BATT_HOT_OVRDE)
319 		return POWER_SUPPLY_HEALTH_OVERHEAT;
320 
321 	if (reg & WM8350_CHG_BATT_COLD_OVRDE)
322 		return POWER_SUPPLY_HEALTH_COLD;
323 
324 	return POWER_SUPPLY_HEALTH_GOOD;
325 }
326 
wm8350_bat_get_charge_type(struct wm8350 * wm8350)327 static int wm8350_bat_get_charge_type(struct wm8350 *wm8350)
328 {
329 	int state;
330 
331 	state = wm8350_reg_read(wm8350, WM8350_BATTERY_CHARGER_CONTROL_2) &
332 	    WM8350_CHG_STS_MASK;
333 	switch (state) {
334 	case WM8350_CHG_STS_OFF:
335 		return POWER_SUPPLY_CHARGE_TYPE_NONE;
336 	case WM8350_CHG_STS_TRICKLE:
337 		return POWER_SUPPLY_CHARGE_TYPE_TRICKLE;
338 	case WM8350_CHG_STS_FAST:
339 		return POWER_SUPPLY_CHARGE_TYPE_FAST;
340 	default:
341 		return POWER_SUPPLY_CHARGE_TYPE_UNKNOWN;
342 	}
343 }
344 
wm8350_bat_get_property(struct power_supply * psy,enum power_supply_property psp,union power_supply_propval * val)345 static int wm8350_bat_get_property(struct power_supply *psy,
346 				   enum power_supply_property psp,
347 				   union power_supply_propval *val)
348 {
349 	struct wm8350 *wm8350 = dev_get_drvdata(psy->dev->parent);
350 	int ret = 0;
351 
352 	switch (psp) {
353 	case POWER_SUPPLY_PROP_STATUS:
354 		val->intval = wm8350_batt_status(wm8350);
355 		break;
356 	case POWER_SUPPLY_PROP_ONLINE:
357 		val->intval = !!(wm8350_get_supplies(wm8350) &
358 				 WM8350_BATT_SUPPLY);
359 		break;
360 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
361 		val->intval = wm8350_read_battery_uvolts(wm8350);
362 		break;
363 	case POWER_SUPPLY_PROP_HEALTH:
364 		val->intval = wm8350_bat_check_health(wm8350);
365 		break;
366 	case POWER_SUPPLY_PROP_CHARGE_TYPE:
367 		val->intval = wm8350_bat_get_charge_type(wm8350);
368 		break;
369 	default:
370 		ret = -EINVAL;
371 		break;
372 	}
373 
374 	return ret;
375 }
376 
377 static enum power_supply_property wm8350_bat_props[] = {
378 	POWER_SUPPLY_PROP_STATUS,
379 	POWER_SUPPLY_PROP_ONLINE,
380 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
381 	POWER_SUPPLY_PROP_HEALTH,
382 	POWER_SUPPLY_PROP_CHARGE_TYPE,
383 };
384 
385 /*********************************************************************
386  *		Initialisation
387  *********************************************************************/
388 
wm8350_init_charger(struct wm8350 * wm8350)389 static void wm8350_init_charger(struct wm8350 *wm8350)
390 {
391 	/* register our interest in charger events */
392 	wm8350_register_irq(wm8350, WM8350_IRQ_CHG_BAT_HOT,
393 			    wm8350_charger_handler, 0, "Battery hot", wm8350);
394 	wm8350_register_irq(wm8350, WM8350_IRQ_CHG_BAT_COLD,
395 			    wm8350_charger_handler, 0, "Battery cold", wm8350);
396 	wm8350_register_irq(wm8350, WM8350_IRQ_CHG_BAT_FAIL,
397 			    wm8350_charger_handler, 0, "Battery fail", wm8350);
398 	wm8350_register_irq(wm8350, WM8350_IRQ_CHG_TO,
399 			    wm8350_charger_handler, 0,
400 			    "Charger timeout", wm8350);
401 	wm8350_register_irq(wm8350, WM8350_IRQ_CHG_END,
402 			    wm8350_charger_handler, 0,
403 			    "Charge end", wm8350);
404 	wm8350_register_irq(wm8350, WM8350_IRQ_CHG_START,
405 			    wm8350_charger_handler, 0,
406 			    "Charge start", wm8350);
407 	wm8350_register_irq(wm8350, WM8350_IRQ_CHG_FAST_RDY,
408 			    wm8350_charger_handler, 0,
409 			    "Fast charge ready", wm8350);
410 	wm8350_register_irq(wm8350, WM8350_IRQ_CHG_VBATT_LT_3P9,
411 			    wm8350_charger_handler, 0,
412 			    "Battery <3.9V", wm8350);
413 	wm8350_register_irq(wm8350, WM8350_IRQ_CHG_VBATT_LT_3P1,
414 			    wm8350_charger_handler, 0,
415 			    "Battery <3.1V", wm8350);
416 	wm8350_register_irq(wm8350, WM8350_IRQ_CHG_VBATT_LT_2P85,
417 			    wm8350_charger_handler, 0,
418 			    "Battery <2.85V", wm8350);
419 
420 	/* and supply change events */
421 	wm8350_register_irq(wm8350, WM8350_IRQ_EXT_USB_FB,
422 			    wm8350_charger_handler, 0, "USB", wm8350);
423 	wm8350_register_irq(wm8350, WM8350_IRQ_EXT_WALL_FB,
424 			    wm8350_charger_handler, 0, "Wall", wm8350);
425 	wm8350_register_irq(wm8350, WM8350_IRQ_EXT_BAT_FB,
426 			    wm8350_charger_handler, 0, "Battery", wm8350);
427 }
428 
free_charger_irq(struct wm8350 * wm8350)429 static void free_charger_irq(struct wm8350 *wm8350)
430 {
431 	wm8350_free_irq(wm8350, WM8350_IRQ_CHG_BAT_HOT, wm8350);
432 	wm8350_free_irq(wm8350, WM8350_IRQ_CHG_BAT_COLD, wm8350);
433 	wm8350_free_irq(wm8350, WM8350_IRQ_CHG_BAT_FAIL, wm8350);
434 	wm8350_free_irq(wm8350, WM8350_IRQ_CHG_TO, wm8350);
435 	wm8350_free_irq(wm8350, WM8350_IRQ_CHG_END, wm8350);
436 	wm8350_free_irq(wm8350, WM8350_IRQ_CHG_START, wm8350);
437 	wm8350_free_irq(wm8350, WM8350_IRQ_CHG_VBATT_LT_3P9, wm8350);
438 	wm8350_free_irq(wm8350, WM8350_IRQ_CHG_VBATT_LT_3P1, wm8350);
439 	wm8350_free_irq(wm8350, WM8350_IRQ_CHG_VBATT_LT_2P85, wm8350);
440 	wm8350_free_irq(wm8350, WM8350_IRQ_EXT_USB_FB, wm8350);
441 	wm8350_free_irq(wm8350, WM8350_IRQ_EXT_WALL_FB, wm8350);
442 	wm8350_free_irq(wm8350, WM8350_IRQ_EXT_BAT_FB, wm8350);
443 }
444 
wm8350_power_probe(struct platform_device * pdev)445 static int wm8350_power_probe(struct platform_device *pdev)
446 {
447 	struct wm8350 *wm8350 = platform_get_drvdata(pdev);
448 	struct wm8350_power *power = &wm8350->power;
449 	struct wm8350_charger_policy *policy = power->policy;
450 	struct power_supply *usb = &power->usb;
451 	struct power_supply *battery = &power->battery;
452 	struct power_supply *ac = &power->ac;
453 	int ret;
454 
455 	ac->name = "wm8350-ac";
456 	ac->type = POWER_SUPPLY_TYPE_MAINS;
457 	ac->properties = wm8350_ac_props;
458 	ac->num_properties = ARRAY_SIZE(wm8350_ac_props);
459 	ac->get_property = wm8350_ac_get_prop;
460 	ret = power_supply_register(&pdev->dev, ac);
461 	if (ret)
462 		return ret;
463 
464 	battery->name = "wm8350-battery";
465 	battery->properties = wm8350_bat_props;
466 	battery->num_properties = ARRAY_SIZE(wm8350_bat_props);
467 	battery->get_property = wm8350_bat_get_property;
468 	battery->use_for_apm = 1;
469 	ret = power_supply_register(&pdev->dev, battery);
470 	if (ret)
471 		goto battery_failed;
472 
473 	usb->name = "wm8350-usb",
474 	usb->type = POWER_SUPPLY_TYPE_USB;
475 	usb->properties = wm8350_usb_props;
476 	usb->num_properties = ARRAY_SIZE(wm8350_usb_props);
477 	usb->get_property = wm8350_usb_get_prop;
478 	ret = power_supply_register(&pdev->dev, usb);
479 	if (ret)
480 		goto usb_failed;
481 
482 	ret = device_create_file(&pdev->dev, &dev_attr_charger_state);
483 	if (ret < 0)
484 		dev_warn(wm8350->dev, "failed to add charge sysfs: %d\n", ret);
485 	ret = 0;
486 
487 	wm8350_init_charger(wm8350);
488 	if (wm8350_charger_config(wm8350, policy) == 0) {
489 		wm8350_reg_unlock(wm8350);
490 		wm8350_set_bits(wm8350, WM8350_POWER_MGMT_5, WM8350_CHG_ENA);
491 		wm8350_reg_lock(wm8350);
492 	}
493 
494 	return ret;
495 
496 usb_failed:
497 	power_supply_unregister(battery);
498 battery_failed:
499 	power_supply_unregister(ac);
500 
501 	return ret;
502 }
503 
wm8350_power_remove(struct platform_device * pdev)504 static int wm8350_power_remove(struct platform_device *pdev)
505 {
506 	struct wm8350 *wm8350 = platform_get_drvdata(pdev);
507 	struct wm8350_power *power = &wm8350->power;
508 
509 	free_charger_irq(wm8350);
510 	device_remove_file(&pdev->dev, &dev_attr_charger_state);
511 	power_supply_unregister(&power->battery);
512 	power_supply_unregister(&power->ac);
513 	power_supply_unregister(&power->usb);
514 	return 0;
515 }
516 
517 static struct platform_driver wm8350_power_driver = {
518 	.probe = wm8350_power_probe,
519 	.remove = wm8350_power_remove,
520 	.driver = {
521 		.name = "wm8350-power",
522 	},
523 };
524 
525 module_platform_driver(wm8350_power_driver);
526 
527 MODULE_LICENSE("GPL");
528 MODULE_DESCRIPTION("Power supply driver for WM8350");
529 MODULE_ALIAS("platform:wm8350-power");
530