1 /*
2  * Battery measurement code for Ingenic JZ SOC.
3  *
4  * Copyright (C) 2009 Jiejing Zhang <kzjeef@gmail.com>
5  * Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
6  *
7  * based on tosa_battery.c
8  *
9  * Copyright (C) 2008 Marek Vasut <marek.vasut@gmail.com>
10 *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License version 2 as
13  * published by the Free Software Foundation.
14  *
15  */
16 
17 #include <linux/interrupt.h>
18 #include <linux/kernel.h>
19 #include <linux/module.h>
20 #include <linux/platform_device.h>
21 #include <linux/slab.h>
22 #include <linux/io.h>
23 
24 #include <linux/delay.h>
25 #include <linux/gpio.h>
26 #include <linux/mfd/core.h>
27 #include <linux/power_supply.h>
28 
29 #include <linux/power/jz4740-battery.h>
30 #include <linux/jz4740-adc.h>
31 
32 struct jz_battery {
33 	struct jz_battery_platform_data *pdata;
34 	struct platform_device *pdev;
35 
36 	struct resource *mem;
37 	void __iomem *base;
38 
39 	int irq;
40 	int charge_irq;
41 
42 	const struct mfd_cell *cell;
43 
44 	int status;
45 	long voltage;
46 
47 	struct completion read_completion;
48 
49 	struct power_supply battery;
50 	struct delayed_work work;
51 
52 	struct mutex lock;
53 };
54 
psy_to_jz_battery(struct power_supply * psy)55 static inline struct jz_battery *psy_to_jz_battery(struct power_supply *psy)
56 {
57 	return container_of(psy, struct jz_battery, battery);
58 }
59 
jz_battery_irq_handler(int irq,void * devid)60 static irqreturn_t jz_battery_irq_handler(int irq, void *devid)
61 {
62 	struct jz_battery *battery = devid;
63 
64 	complete(&battery->read_completion);
65 	return IRQ_HANDLED;
66 }
67 
jz_battery_read_voltage(struct jz_battery * battery)68 static long jz_battery_read_voltage(struct jz_battery *battery)
69 {
70 	long t;
71 	unsigned long val;
72 	long voltage;
73 
74 	mutex_lock(&battery->lock);
75 
76 	INIT_COMPLETION(battery->read_completion);
77 
78 	enable_irq(battery->irq);
79 	battery->cell->enable(battery->pdev);
80 
81 	t = wait_for_completion_interruptible_timeout(&battery->read_completion,
82 		HZ);
83 
84 	if (t > 0) {
85 		val = readw(battery->base) & 0xfff;
86 
87 		if (battery->pdata->info.voltage_max_design <= 2500000)
88 			val = (val * 78125UL) >> 7UL;
89 		else
90 			val = ((val * 924375UL) >> 9UL) + 33000;
91 		voltage = (long)val;
92 	} else {
93 		voltage = t ? t : -ETIMEDOUT;
94 	}
95 
96 	battery->cell->disable(battery->pdev);
97 	disable_irq(battery->irq);
98 
99 	mutex_unlock(&battery->lock);
100 
101 	return voltage;
102 }
103 
jz_battery_get_capacity(struct power_supply * psy)104 static int jz_battery_get_capacity(struct power_supply *psy)
105 {
106 	struct jz_battery *jz_battery = psy_to_jz_battery(psy);
107 	struct power_supply_info *info = &jz_battery->pdata->info;
108 	long voltage;
109 	int ret;
110 	int voltage_span;
111 
112 	voltage = jz_battery_read_voltage(jz_battery);
113 
114 	if (voltage < 0)
115 		return voltage;
116 
117 	voltage_span = info->voltage_max_design - info->voltage_min_design;
118 	ret = ((voltage - info->voltage_min_design) * 100) / voltage_span;
119 
120 	if (ret > 100)
121 		ret = 100;
122 	else if (ret < 0)
123 		ret = 0;
124 
125 	return ret;
126 }
127 
jz_battery_get_property(struct power_supply * psy,enum power_supply_property psp,union power_supply_propval * val)128 static int jz_battery_get_property(struct power_supply *psy,
129 	enum power_supply_property psp, union power_supply_propval *val)
130 {
131 	struct jz_battery *jz_battery = psy_to_jz_battery(psy);
132 	struct power_supply_info *info = &jz_battery->pdata->info;
133 	long voltage;
134 
135 	switch (psp) {
136 	case POWER_SUPPLY_PROP_STATUS:
137 		val->intval = jz_battery->status;
138 		break;
139 	case POWER_SUPPLY_PROP_TECHNOLOGY:
140 		val->intval = jz_battery->pdata->info.technology;
141 		break;
142 	case POWER_SUPPLY_PROP_HEALTH:
143 		voltage = jz_battery_read_voltage(jz_battery);
144 		if (voltage < info->voltage_min_design)
145 			val->intval = POWER_SUPPLY_HEALTH_DEAD;
146 		else
147 			val->intval = POWER_SUPPLY_HEALTH_GOOD;
148 		break;
149 	case POWER_SUPPLY_PROP_CAPACITY:
150 		val->intval = jz_battery_get_capacity(psy);
151 		break;
152 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
153 		val->intval = jz_battery_read_voltage(jz_battery);
154 		if (val->intval < 0)
155 			return val->intval;
156 		break;
157 	case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
158 		val->intval = info->voltage_max_design;
159 		break;
160 	case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
161 		val->intval = info->voltage_min_design;
162 		break;
163 	case POWER_SUPPLY_PROP_PRESENT:
164 		val->intval = 1;
165 		break;
166 	default:
167 		return -EINVAL;
168 	}
169 	return 0;
170 }
171 
jz_battery_external_power_changed(struct power_supply * psy)172 static void jz_battery_external_power_changed(struct power_supply *psy)
173 {
174 	struct jz_battery *jz_battery = psy_to_jz_battery(psy);
175 
176 	cancel_delayed_work(&jz_battery->work);
177 	schedule_delayed_work(&jz_battery->work, 0);
178 }
179 
jz_battery_charge_irq(int irq,void * data)180 static irqreturn_t jz_battery_charge_irq(int irq, void *data)
181 {
182 	struct jz_battery *jz_battery = data;
183 
184 	cancel_delayed_work(&jz_battery->work);
185 	schedule_delayed_work(&jz_battery->work, 0);
186 
187 	return IRQ_HANDLED;
188 }
189 
jz_battery_update(struct jz_battery * jz_battery)190 static void jz_battery_update(struct jz_battery *jz_battery)
191 {
192 	int status;
193 	long voltage;
194 	bool has_changed = false;
195 	int is_charging;
196 
197 	if (gpio_is_valid(jz_battery->pdata->gpio_charge)) {
198 		is_charging = gpio_get_value(jz_battery->pdata->gpio_charge);
199 		is_charging ^= jz_battery->pdata->gpio_charge_active_low;
200 		if (is_charging)
201 			status = POWER_SUPPLY_STATUS_CHARGING;
202 		else
203 			status = POWER_SUPPLY_STATUS_NOT_CHARGING;
204 
205 		if (status != jz_battery->status) {
206 			jz_battery->status = status;
207 			has_changed = true;
208 		}
209 	}
210 
211 	voltage = jz_battery_read_voltage(jz_battery);
212 	if (abs(voltage - jz_battery->voltage) < 50000) {
213 		jz_battery->voltage = voltage;
214 		has_changed = true;
215 	}
216 
217 	if (has_changed)
218 		power_supply_changed(&jz_battery->battery);
219 }
220 
221 static enum power_supply_property jz_battery_properties[] = {
222 	POWER_SUPPLY_PROP_STATUS,
223 	POWER_SUPPLY_PROP_TECHNOLOGY,
224 	POWER_SUPPLY_PROP_HEALTH,
225 	POWER_SUPPLY_PROP_CAPACITY,
226 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
227 	POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
228 	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
229 	POWER_SUPPLY_PROP_PRESENT,
230 };
231 
jz_battery_work(struct work_struct * work)232 static void jz_battery_work(struct work_struct *work)
233 {
234 	/* Too small interval will increase system workload */
235 	const int interval = HZ * 30;
236 	struct jz_battery *jz_battery = container_of(work, struct jz_battery,
237 					    work.work);
238 
239 	jz_battery_update(jz_battery);
240 	schedule_delayed_work(&jz_battery->work, interval);
241 }
242 
jz_battery_probe(struct platform_device * pdev)243 static int __devinit jz_battery_probe(struct platform_device *pdev)
244 {
245 	int ret = 0;
246 	struct jz_battery_platform_data *pdata = pdev->dev.parent->platform_data;
247 	struct jz_battery *jz_battery;
248 	struct power_supply *battery;
249 
250 	if (!pdata) {
251 		dev_err(&pdev->dev, "No platform_data supplied\n");
252 		return -ENXIO;
253 	}
254 
255 	jz_battery = kzalloc(sizeof(*jz_battery), GFP_KERNEL);
256 	if (!jz_battery) {
257 		dev_err(&pdev->dev, "Failed to allocate driver structure\n");
258 		return -ENOMEM;
259 	}
260 
261 	jz_battery->cell = mfd_get_cell(pdev);
262 
263 	jz_battery->irq = platform_get_irq(pdev, 0);
264 	if (jz_battery->irq < 0) {
265 		ret = jz_battery->irq;
266 		dev_err(&pdev->dev, "Failed to get platform irq: %d\n", ret);
267 		goto err_free;
268 	}
269 
270 	jz_battery->mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
271 	if (!jz_battery->mem) {
272 		ret = -ENOENT;
273 		dev_err(&pdev->dev, "Failed to get platform mmio resource\n");
274 		goto err_free;
275 	}
276 
277 	jz_battery->mem = request_mem_region(jz_battery->mem->start,
278 				resource_size(jz_battery->mem),	pdev->name);
279 	if (!jz_battery->mem) {
280 		ret = -EBUSY;
281 		dev_err(&pdev->dev, "Failed to request mmio memory region\n");
282 		goto err_free;
283 	}
284 
285 	jz_battery->base = ioremap_nocache(jz_battery->mem->start,
286 				resource_size(jz_battery->mem));
287 	if (!jz_battery->base) {
288 		ret = -EBUSY;
289 		dev_err(&pdev->dev, "Failed to ioremap mmio memory\n");
290 		goto err_release_mem_region;
291 	}
292 
293 	battery = &jz_battery->battery;
294 	battery->name = pdata->info.name;
295 	battery->type = POWER_SUPPLY_TYPE_BATTERY;
296 	battery->properties	= jz_battery_properties;
297 	battery->num_properties	= ARRAY_SIZE(jz_battery_properties);
298 	battery->get_property = jz_battery_get_property;
299 	battery->external_power_changed = jz_battery_external_power_changed;
300 	battery->use_for_apm = 1;
301 
302 	jz_battery->pdata = pdata;
303 	jz_battery->pdev = pdev;
304 
305 	init_completion(&jz_battery->read_completion);
306 	mutex_init(&jz_battery->lock);
307 
308 	INIT_DELAYED_WORK(&jz_battery->work, jz_battery_work);
309 
310 	ret = request_irq(jz_battery->irq, jz_battery_irq_handler, 0, pdev->name,
311 			jz_battery);
312 	if (ret) {
313 		dev_err(&pdev->dev, "Failed to request irq %d\n", ret);
314 		goto err_iounmap;
315 	}
316 	disable_irq(jz_battery->irq);
317 
318 	if (gpio_is_valid(pdata->gpio_charge)) {
319 		ret = gpio_request(pdata->gpio_charge, dev_name(&pdev->dev));
320 		if (ret) {
321 			dev_err(&pdev->dev, "charger state gpio request failed.\n");
322 			goto err_free_irq;
323 		}
324 		ret = gpio_direction_input(pdata->gpio_charge);
325 		if (ret) {
326 			dev_err(&pdev->dev, "charger state gpio set direction failed.\n");
327 			goto err_free_gpio;
328 		}
329 
330 		jz_battery->charge_irq = gpio_to_irq(pdata->gpio_charge);
331 
332 		if (jz_battery->charge_irq >= 0) {
333 			ret = request_irq(jz_battery->charge_irq,
334 				    jz_battery_charge_irq,
335 				    IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
336 				    dev_name(&pdev->dev), jz_battery);
337 			if (ret) {
338 				dev_err(&pdev->dev, "Failed to request charge irq: %d\n", ret);
339 				goto err_free_gpio;
340 			}
341 		}
342 	} else {
343 		jz_battery->charge_irq = -1;
344 	}
345 
346 	if (jz_battery->pdata->info.voltage_max_design <= 2500000)
347 		jz4740_adc_set_config(pdev->dev.parent, JZ_ADC_CONFIG_BAT_MB,
348 			JZ_ADC_CONFIG_BAT_MB);
349 	else
350 		jz4740_adc_set_config(pdev->dev.parent, JZ_ADC_CONFIG_BAT_MB, 0);
351 
352 	ret = power_supply_register(&pdev->dev, &jz_battery->battery);
353 	if (ret) {
354 		dev_err(&pdev->dev, "power supply battery register failed.\n");
355 		goto err_free_charge_irq;
356 	}
357 
358 	platform_set_drvdata(pdev, jz_battery);
359 	schedule_delayed_work(&jz_battery->work, 0);
360 
361 	return 0;
362 
363 err_free_charge_irq:
364 	if (jz_battery->charge_irq >= 0)
365 		free_irq(jz_battery->charge_irq, jz_battery);
366 err_free_gpio:
367 	if (gpio_is_valid(pdata->gpio_charge))
368 		gpio_free(jz_battery->pdata->gpio_charge);
369 err_free_irq:
370 	free_irq(jz_battery->irq, jz_battery);
371 err_iounmap:
372 	platform_set_drvdata(pdev, NULL);
373 	iounmap(jz_battery->base);
374 err_release_mem_region:
375 	release_mem_region(jz_battery->mem->start, resource_size(jz_battery->mem));
376 err_free:
377 	kfree(jz_battery);
378 	return ret;
379 }
380 
jz_battery_remove(struct platform_device * pdev)381 static int __devexit jz_battery_remove(struct platform_device *pdev)
382 {
383 	struct jz_battery *jz_battery = platform_get_drvdata(pdev);
384 
385 	cancel_delayed_work_sync(&jz_battery->work);
386 
387 	if (gpio_is_valid(jz_battery->pdata->gpio_charge)) {
388 		if (jz_battery->charge_irq >= 0)
389 			free_irq(jz_battery->charge_irq, jz_battery);
390 		gpio_free(jz_battery->pdata->gpio_charge);
391 	}
392 
393 	power_supply_unregister(&jz_battery->battery);
394 
395 	free_irq(jz_battery->irq, jz_battery);
396 
397 	iounmap(jz_battery->base);
398 	release_mem_region(jz_battery->mem->start, resource_size(jz_battery->mem));
399 	kfree(jz_battery);
400 
401 	return 0;
402 }
403 
404 #ifdef CONFIG_PM
jz_battery_suspend(struct device * dev)405 static int jz_battery_suspend(struct device *dev)
406 {
407 	struct jz_battery *jz_battery = dev_get_drvdata(dev);
408 
409 	cancel_delayed_work_sync(&jz_battery->work);
410 	jz_battery->status = POWER_SUPPLY_STATUS_UNKNOWN;
411 
412 	return 0;
413 }
414 
jz_battery_resume(struct device * dev)415 static int jz_battery_resume(struct device *dev)
416 {
417 	struct jz_battery *jz_battery = dev_get_drvdata(dev);
418 
419 	schedule_delayed_work(&jz_battery->work, 0);
420 
421 	return 0;
422 }
423 
424 static const struct dev_pm_ops jz_battery_pm_ops = {
425 	.suspend	= jz_battery_suspend,
426 	.resume		= jz_battery_resume,
427 };
428 
429 #define JZ_BATTERY_PM_OPS (&jz_battery_pm_ops)
430 #else
431 #define JZ_BATTERY_PM_OPS NULL
432 #endif
433 
434 static struct platform_driver jz_battery_driver = {
435 	.probe		= jz_battery_probe,
436 	.remove		= __devexit_p(jz_battery_remove),
437 	.driver = {
438 		.name = "jz4740-battery",
439 		.owner = THIS_MODULE,
440 		.pm = JZ_BATTERY_PM_OPS,
441 	},
442 };
443 
444 module_platform_driver(jz_battery_driver);
445 
446 MODULE_ALIAS("platform:jz4740-battery");
447 MODULE_LICENSE("GPL");
448 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
449 MODULE_DESCRIPTION("JZ4740 SoC battery driver");
450