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/err.h>
 26#include <linux/gpio.h>
 27#include <linux/mfd/core.h>
 28#include <linux/power_supply.h>
 29
 30#include <linux/power/jz4740-battery.h>
 31#include <linux/jz4740-adc.h>
 32
 33struct jz_battery {
 34	struct jz_battery_platform_data *pdata;
 35	struct platform_device *pdev;
 36
 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
 55static inline struct jz_battery *psy_to_jz_battery(struct power_supply *psy)
 56{
 57	return container_of(psy, struct jz_battery, battery);
 58}
 59
 60static 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
 68static 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	reinit_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
104static 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
128static 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
172static void jz_battery_external_power_changed(struct power_supply *psy)
173{
174	struct jz_battery *jz_battery = psy_to_jz_battery(psy);
175
176	mod_delayed_work(system_wq, &jz_battery->work, 0);
177}
178
179static irqreturn_t jz_battery_charge_irq(int irq, void *data)
180{
181	struct jz_battery *jz_battery = data;
182
183	mod_delayed_work(system_wq, &jz_battery->work, 0);
184
185	return IRQ_HANDLED;
186}
187
188static void jz_battery_update(struct jz_battery *jz_battery)
189{
190	int status;
191	long voltage;
192	bool has_changed = false;
193	int is_charging;
194
195	if (gpio_is_valid(jz_battery->pdata->gpio_charge)) {
196		is_charging = gpio_get_value(jz_battery->pdata->gpio_charge);
197		is_charging ^= jz_battery->pdata->gpio_charge_active_low;
198		if (is_charging)
199			status = POWER_SUPPLY_STATUS_CHARGING;
200		else
201			status = POWER_SUPPLY_STATUS_NOT_CHARGING;
202
203		if (status != jz_battery->status) {
204			jz_battery->status = status;
205			has_changed = true;
206		}
207	}
208
209	voltage = jz_battery_read_voltage(jz_battery);
210	if (abs(voltage - jz_battery->voltage) < 50000) {
211		jz_battery->voltage = voltage;
212		has_changed = true;
213	}
214
215	if (has_changed)
216		power_supply_changed(&jz_battery->battery);
217}
218
219static enum power_supply_property jz_battery_properties[] = {
220	POWER_SUPPLY_PROP_STATUS,
221	POWER_SUPPLY_PROP_TECHNOLOGY,
222	POWER_SUPPLY_PROP_HEALTH,
223	POWER_SUPPLY_PROP_CAPACITY,
224	POWER_SUPPLY_PROP_VOLTAGE_NOW,
225	POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
226	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
227	POWER_SUPPLY_PROP_PRESENT,
228};
229
230static void jz_battery_work(struct work_struct *work)
231{
232	/* Too small interval will increase system workload */
233	const int interval = HZ * 30;
234	struct jz_battery *jz_battery = container_of(work, struct jz_battery,
235					    work.work);
236
237	jz_battery_update(jz_battery);
238	schedule_delayed_work(&jz_battery->work, interval);
239}
240
241static int jz_battery_probe(struct platform_device *pdev)
242{
243	int ret = 0;
244	struct jz_battery_platform_data *pdata = pdev->dev.parent->platform_data;
245	struct jz_battery *jz_battery;
246	struct power_supply *battery;
247	struct resource *mem;
248
249	if (!pdata) {
250		dev_err(&pdev->dev, "No platform_data supplied\n");
251		return -ENXIO;
252	}
253
254	jz_battery = devm_kzalloc(&pdev->dev, sizeof(*jz_battery), GFP_KERNEL);
255	if (!jz_battery) {
256		dev_err(&pdev->dev, "Failed to allocate driver structure\n");
257		return -ENOMEM;
258	}
259
260	jz_battery->cell = mfd_get_cell(pdev);
261
262	jz_battery->irq = platform_get_irq(pdev, 0);
263	if (jz_battery->irq < 0) {
264		dev_err(&pdev->dev, "Failed to get platform irq: %d\n", ret);
265		return jz_battery->irq;
266	}
267
268	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
269
270	jz_battery->base = devm_ioremap_resource(&pdev->dev, mem);
271	if (IS_ERR(jz_battery->base))
272		return PTR_ERR(jz_battery->base);
273
274	battery = &jz_battery->battery;
275	battery->name = pdata->info.name;
276	battery->type = POWER_SUPPLY_TYPE_BATTERY;
277	battery->properties	= jz_battery_properties;
278	battery->num_properties	= ARRAY_SIZE(jz_battery_properties);
279	battery->get_property = jz_battery_get_property;
280	battery->external_power_changed = jz_battery_external_power_changed;
281	battery->use_for_apm = 1;
282
283	jz_battery->pdata = pdata;
284	jz_battery->pdev = pdev;
285
286	init_completion(&jz_battery->read_completion);
287	mutex_init(&jz_battery->lock);
288
289	INIT_DELAYED_WORK(&jz_battery->work, jz_battery_work);
290
291	ret = request_irq(jz_battery->irq, jz_battery_irq_handler, 0, pdev->name,
292			jz_battery);
293	if (ret) {
294		dev_err(&pdev->dev, "Failed to request irq %d\n", ret);
295		return ret;
296	}
297	disable_irq(jz_battery->irq);
298
299	if (gpio_is_valid(pdata->gpio_charge)) {
300		ret = gpio_request(pdata->gpio_charge, dev_name(&pdev->dev));
301		if (ret) {
302			dev_err(&pdev->dev, "charger state gpio request failed.\n");
303			goto err_free_irq;
304		}
305		ret = gpio_direction_input(pdata->gpio_charge);
306		if (ret) {
307			dev_err(&pdev->dev, "charger state gpio set direction failed.\n");
308			goto err_free_gpio;
309		}
310
311		jz_battery->charge_irq = gpio_to_irq(pdata->gpio_charge);
312
313		if (jz_battery->charge_irq >= 0) {
314			ret = request_irq(jz_battery->charge_irq,
315				    jz_battery_charge_irq,
316				    IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
317				    dev_name(&pdev->dev), jz_battery);
318			if (ret) {
319				dev_err(&pdev->dev, "Failed to request charge irq: %d\n", ret);
320				goto err_free_gpio;
321			}
322		}
323	} else {
324		jz_battery->charge_irq = -1;
325	}
326
327	if (jz_battery->pdata->info.voltage_max_design <= 2500000)
328		jz4740_adc_set_config(pdev->dev.parent, JZ_ADC_CONFIG_BAT_MB,
329			JZ_ADC_CONFIG_BAT_MB);
330	else
331		jz4740_adc_set_config(pdev->dev.parent, JZ_ADC_CONFIG_BAT_MB, 0);
332
333	ret = power_supply_register(&pdev->dev, &jz_battery->battery);
334	if (ret) {
335		dev_err(&pdev->dev, "power supply battery register failed.\n");
336		goto err_free_charge_irq;
337	}
338
339	platform_set_drvdata(pdev, jz_battery);
340	schedule_delayed_work(&jz_battery->work, 0);
341
342	return 0;
343
344err_free_charge_irq:
345	if (jz_battery->charge_irq >= 0)
346		free_irq(jz_battery->charge_irq, jz_battery);
347err_free_gpio:
348	if (gpio_is_valid(pdata->gpio_charge))
349		gpio_free(jz_battery->pdata->gpio_charge);
350err_free_irq:
351	free_irq(jz_battery->irq, jz_battery);
352	return ret;
353}
354
355static int jz_battery_remove(struct platform_device *pdev)
356{
357	struct jz_battery *jz_battery = platform_get_drvdata(pdev);
358
359	cancel_delayed_work_sync(&jz_battery->work);
360
361	if (gpio_is_valid(jz_battery->pdata->gpio_charge)) {
362		if (jz_battery->charge_irq >= 0)
363			free_irq(jz_battery->charge_irq, jz_battery);
364		gpio_free(jz_battery->pdata->gpio_charge);
365	}
366
367	power_supply_unregister(&jz_battery->battery);
368
369	free_irq(jz_battery->irq, jz_battery);
370
371	return 0;
372}
373
374#ifdef CONFIG_PM
375static int jz_battery_suspend(struct device *dev)
376{
377	struct jz_battery *jz_battery = dev_get_drvdata(dev);
378
379	cancel_delayed_work_sync(&jz_battery->work);
380	jz_battery->status = POWER_SUPPLY_STATUS_UNKNOWN;
381
382	return 0;
383}
384
385static int jz_battery_resume(struct device *dev)
386{
387	struct jz_battery *jz_battery = dev_get_drvdata(dev);
388
389	schedule_delayed_work(&jz_battery->work, 0);
390
391	return 0;
392}
393
394static const struct dev_pm_ops jz_battery_pm_ops = {
395	.suspend	= jz_battery_suspend,
396	.resume		= jz_battery_resume,
397};
398
399#define JZ_BATTERY_PM_OPS (&jz_battery_pm_ops)
400#else
401#define JZ_BATTERY_PM_OPS NULL
402#endif
403
404static struct platform_driver jz_battery_driver = {
405	.probe		= jz_battery_probe,
406	.remove		= jz_battery_remove,
407	.driver = {
408		.name = "jz4740-battery",
409		.owner = THIS_MODULE,
410		.pm = JZ_BATTERY_PM_OPS,
411	},
412};
413
414module_platform_driver(jz_battery_driver);
415
416MODULE_ALIAS("platform:jz4740-battery");
417MODULE_LICENSE("GPL");
418MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
419MODULE_DESCRIPTION("JZ4740 SoC battery driver");