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 power_supply_desc battery_desc;
51	struct delayed_work work;
52
53	struct mutex lock;
54};
55
56static inline struct jz_battery *psy_to_jz_battery(struct power_supply *psy)
57{
58	return power_supply_get_drvdata(psy);
59}
60
61static irqreturn_t jz_battery_irq_handler(int irq, void *devid)
62{
63	struct jz_battery *battery = devid;
64
65	complete(&battery->read_completion);
66	return IRQ_HANDLED;
67}
68
69static long jz_battery_read_voltage(struct jz_battery *battery)
70{
71	long t;
72	unsigned long val;
73	long voltage;
74
75	mutex_lock(&battery->lock);
76
77	reinit_completion(&battery->read_completion);
78
79	enable_irq(battery->irq);
80	battery->cell->enable(battery->pdev);
81
82	t = wait_for_completion_interruptible_timeout(&battery->read_completion,
83		HZ);
84
85	if (t > 0) {
86		val = readw(battery->base) & 0xfff;
87
88		if (battery->pdata->info.voltage_max_design <= 2500000)
89			val = (val * 78125UL) >> 7UL;
90		else
91			val = ((val * 924375UL) >> 9UL) + 33000;
92		voltage = (long)val;
93	} else {
94		voltage = t ? t : -ETIMEDOUT;
95	}
96
97	battery->cell->disable(battery->pdev);
98	disable_irq(battery->irq);
99
100	mutex_unlock(&battery->lock);
101
102	return voltage;
103}
104
105static int jz_battery_get_capacity(struct power_supply *psy)
106{
107	struct jz_battery *jz_battery = psy_to_jz_battery(psy);
108	struct power_supply_info *info = &jz_battery->pdata->info;
109	long voltage;
110	int ret;
111	int voltage_span;
112
113	voltage = jz_battery_read_voltage(jz_battery);
114
115	if (voltage < 0)
116		return voltage;
117
118	voltage_span = info->voltage_max_design - info->voltage_min_design;
119	ret = ((voltage - info->voltage_min_design) * 100) / voltage_span;
120
121	if (ret > 100)
122		ret = 100;
123	else if (ret < 0)
124		ret = 0;
125
126	return ret;
127}
128
129static int jz_battery_get_property(struct power_supply *psy,
130	enum power_supply_property psp, union power_supply_propval *val)
131{
132	struct jz_battery *jz_battery = psy_to_jz_battery(psy);
133	struct power_supply_info *info = &jz_battery->pdata->info;
134	long voltage;
135
136	switch (psp) {
137	case POWER_SUPPLY_PROP_STATUS:
138		val->intval = jz_battery->status;
139		break;
140	case POWER_SUPPLY_PROP_TECHNOLOGY:
141		val->intval = jz_battery->pdata->info.technology;
142		break;
143	case POWER_SUPPLY_PROP_HEALTH:
144		voltage = jz_battery_read_voltage(jz_battery);
145		if (voltage < info->voltage_min_design)
146			val->intval = POWER_SUPPLY_HEALTH_DEAD;
147		else
148			val->intval = POWER_SUPPLY_HEALTH_GOOD;
149		break;
150	case POWER_SUPPLY_PROP_CAPACITY:
151		val->intval = jz_battery_get_capacity(psy);
152		break;
153	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
154		val->intval = jz_battery_read_voltage(jz_battery);
155		if (val->intval < 0)
156			return val->intval;
157		break;
158	case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
159		val->intval = info->voltage_max_design;
160		break;
161	case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
162		val->intval = info->voltage_min_design;
163		break;
164	case POWER_SUPPLY_PROP_PRESENT:
165		val->intval = 1;
166		break;
167	default:
168		return -EINVAL;
169	}
170	return 0;
171}
172
173static void jz_battery_external_power_changed(struct power_supply *psy)
174{
175	struct jz_battery *jz_battery = psy_to_jz_battery(psy);
176
177	mod_delayed_work(system_wq, &jz_battery->work, 0);
178}
179
180static irqreturn_t jz_battery_charge_irq(int irq, void *data)
181{
182	struct jz_battery *jz_battery = data;
183
184	mod_delayed_work(system_wq, &jz_battery->work, 0);
185
186	return IRQ_HANDLED;
187}
188
189static void jz_battery_update(struct jz_battery *jz_battery)
190{
191	int status;
192	long voltage;
193	bool has_changed = false;
194	int is_charging;
195
196	if (gpio_is_valid(jz_battery->pdata->gpio_charge)) {
197		is_charging = gpio_get_value(jz_battery->pdata->gpio_charge);
198		is_charging ^= jz_battery->pdata->gpio_charge_active_low;
199		if (is_charging)
200			status = POWER_SUPPLY_STATUS_CHARGING;
201		else
202			status = POWER_SUPPLY_STATUS_NOT_CHARGING;
203
204		if (status != jz_battery->status) {
205			jz_battery->status = status;
206			has_changed = true;
207		}
208	}
209
210	voltage = jz_battery_read_voltage(jz_battery);
211	if (abs(voltage - jz_battery->voltage) < 50000) {
212		jz_battery->voltage = voltage;
213		has_changed = true;
214	}
215
216	if (has_changed)
217		power_supply_changed(jz_battery->battery);
218}
219
220static enum power_supply_property jz_battery_properties[] = {
221	POWER_SUPPLY_PROP_STATUS,
222	POWER_SUPPLY_PROP_TECHNOLOGY,
223	POWER_SUPPLY_PROP_HEALTH,
224	POWER_SUPPLY_PROP_CAPACITY,
225	POWER_SUPPLY_PROP_VOLTAGE_NOW,
226	POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
227	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
228	POWER_SUPPLY_PROP_PRESENT,
229};
230
231static void jz_battery_work(struct work_struct *work)
232{
233	/* Too small interval will increase system workload */
234	const int interval = HZ * 30;
235	struct jz_battery *jz_battery = container_of(work, struct jz_battery,
236					    work.work);
237
238	jz_battery_update(jz_battery);
239	schedule_delayed_work(&jz_battery->work, interval);
240}
241
242static int jz_battery_probe(struct platform_device *pdev)
243{
244	int ret = 0;
245	struct jz_battery_platform_data *pdata = pdev->dev.parent->platform_data;
246	struct power_supply_config psy_cfg = {};
247	struct jz_battery *jz_battery;
248	struct power_supply_desc *battery_desc;
249	struct resource *mem;
250
251	if (!pdata) {
252		dev_err(&pdev->dev, "No platform_data supplied\n");
253		return -ENXIO;
254	}
255
256	jz_battery = devm_kzalloc(&pdev->dev, sizeof(*jz_battery), GFP_KERNEL);
257	if (!jz_battery) {
258		dev_err(&pdev->dev, "Failed to allocate driver structure\n");
259		return -ENOMEM;
260	}
261
262	jz_battery->cell = mfd_get_cell(pdev);
263
264	jz_battery->irq = platform_get_irq(pdev, 0);
265	if (jz_battery->irq < 0) {
266		dev_err(&pdev->dev, "Failed to get platform irq: %d\n", ret);
267		return jz_battery->irq;
268	}
269
270	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
271
272	jz_battery->base = devm_ioremap_resource(&pdev->dev, mem);
273	if (IS_ERR(jz_battery->base))
274		return PTR_ERR(jz_battery->base);
275
276	battery_desc = &jz_battery->battery_desc;
277	battery_desc->name = pdata->info.name;
278	battery_desc->type = POWER_SUPPLY_TYPE_BATTERY;
279	battery_desc->properties	= jz_battery_properties;
280	battery_desc->num_properties	= ARRAY_SIZE(jz_battery_properties);
281	battery_desc->get_property	= jz_battery_get_property;
282	battery_desc->external_power_changed =
283					jz_battery_external_power_changed;
284	battery_desc->use_for_apm	= 1;
285
286	psy_cfg.drv_data = jz_battery;
287
288	jz_battery->pdata = pdata;
289	jz_battery->pdev = pdev;
290
291	init_completion(&jz_battery->read_completion);
292	mutex_init(&jz_battery->lock);
293
294	INIT_DELAYED_WORK(&jz_battery->work, jz_battery_work);
295
296	ret = request_irq(jz_battery->irq, jz_battery_irq_handler, 0, pdev->name,
297			jz_battery);
298	if (ret) {
299		dev_err(&pdev->dev, "Failed to request irq %d\n", ret);
300		return ret;
301	}
302	disable_irq(jz_battery->irq);
303
304	if (gpio_is_valid(pdata->gpio_charge)) {
305		ret = gpio_request(pdata->gpio_charge, dev_name(&pdev->dev));
306		if (ret) {
307			dev_err(&pdev->dev, "charger state gpio request failed.\n");
308			goto err_free_irq;
309		}
310		ret = gpio_direction_input(pdata->gpio_charge);
311		if (ret) {
312			dev_err(&pdev->dev, "charger state gpio set direction failed.\n");
313			goto err_free_gpio;
314		}
315
316		jz_battery->charge_irq = gpio_to_irq(pdata->gpio_charge);
317
318		if (jz_battery->charge_irq >= 0) {
319			ret = request_irq(jz_battery->charge_irq,
320				    jz_battery_charge_irq,
321				    IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
322				    dev_name(&pdev->dev), jz_battery);
323			if (ret) {
324				dev_err(&pdev->dev, "Failed to request charge irq: %d\n", ret);
325				goto err_free_gpio;
326			}
327		}
328	} else {
329		jz_battery->charge_irq = -1;
330	}
331
332	if (jz_battery->pdata->info.voltage_max_design <= 2500000)
333		jz4740_adc_set_config(pdev->dev.parent, JZ_ADC_CONFIG_BAT_MB,
334			JZ_ADC_CONFIG_BAT_MB);
335	else
336		jz4740_adc_set_config(pdev->dev.parent, JZ_ADC_CONFIG_BAT_MB, 0);
337
338	jz_battery->battery = power_supply_register(&pdev->dev, battery_desc,
339							&psy_cfg);
340	if (IS_ERR(jz_battery->battery)) {
341		dev_err(&pdev->dev, "power supply battery register failed.\n");
342		ret = PTR_ERR(jz_battery->battery);
343		goto err_free_charge_irq;
344	}
345
346	platform_set_drvdata(pdev, jz_battery);
347	schedule_delayed_work(&jz_battery->work, 0);
348
349	return 0;
350
351err_free_charge_irq:
352	if (jz_battery->charge_irq >= 0)
353		free_irq(jz_battery->charge_irq, jz_battery);
354err_free_gpio:
355	if (gpio_is_valid(pdata->gpio_charge))
356		gpio_free(jz_battery->pdata->gpio_charge);
357err_free_irq:
358	free_irq(jz_battery->irq, jz_battery);
359	return ret;
360}
361
362static int jz_battery_remove(struct platform_device *pdev)
363{
364	struct jz_battery *jz_battery = platform_get_drvdata(pdev);
365
366	cancel_delayed_work_sync(&jz_battery->work);
367
368	if (gpio_is_valid(jz_battery->pdata->gpio_charge)) {
369		if (jz_battery->charge_irq >= 0)
370			free_irq(jz_battery->charge_irq, jz_battery);
371		gpio_free(jz_battery->pdata->gpio_charge);
372	}
373
374	power_supply_unregister(jz_battery->battery);
375
376	free_irq(jz_battery->irq, jz_battery);
377
378	return 0;
379}
380
381#ifdef CONFIG_PM
382static int jz_battery_suspend(struct device *dev)
383{
384	struct jz_battery *jz_battery = dev_get_drvdata(dev);
385
386	cancel_delayed_work_sync(&jz_battery->work);
387	jz_battery->status = POWER_SUPPLY_STATUS_UNKNOWN;
388
389	return 0;
390}
391
392static int jz_battery_resume(struct device *dev)
393{
394	struct jz_battery *jz_battery = dev_get_drvdata(dev);
395
396	schedule_delayed_work(&jz_battery->work, 0);
397
398	return 0;
399}
400
401static const struct dev_pm_ops jz_battery_pm_ops = {
402	.suspend	= jz_battery_suspend,
403	.resume		= jz_battery_resume,
404};
405
406#define JZ_BATTERY_PM_OPS (&jz_battery_pm_ops)
407#else
408#define JZ_BATTERY_PM_OPS NULL
409#endif
410
411static struct platform_driver jz_battery_driver = {
412	.probe		= jz_battery_probe,
413	.remove		= jz_battery_remove,
414	.driver = {
415		.name = "jz4740-battery",
416		.pm = JZ_BATTERY_PM_OPS,
417	},
418};
419
420module_platform_driver(jz_battery_driver);
421
422MODULE_ALIAS("platform:jz4740-battery");
423MODULE_LICENSE("GPL");
424MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
425MODULE_DESCRIPTION("JZ4740 SoC battery driver");
426