1/*
2 * linux/drivers/power/wm97xx_battery.c
3 *
4 * Battery measurement code for WM97xx
5 *
6 * based on tosa_battery.c
7 *
8 * Copyright (C) 2008 Marek Vasut <marek.vasut@gmail.com>
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
16#include <linux/init.h>
17#include <linux/kernel.h>
18#include <linux/module.h>
19#include <linux/platform_device.h>
20#include <linux/power_supply.h>
21#include <linux/wm97xx.h>
22#include <linux/spinlock.h>
23#include <linux/interrupt.h>
24#include <linux/gpio.h>
25#include <linux/irq.h>
26#include <linux/slab.h>
27
28static struct work_struct bat_work;
29static DEFINE_MUTEX(work_lock);
30static int bat_status = POWER_SUPPLY_STATUS_UNKNOWN;
31static enum power_supply_property *prop;
32
33static unsigned long wm97xx_read_bat(struct power_supply *bat_ps)
34{
35	struct wm97xx_pdata *wmdata = bat_ps->dev.parent->platform_data;
36	struct wm97xx_batt_pdata *pdata = wmdata->batt_pdata;
37
38	return wm97xx_read_aux_adc(dev_get_drvdata(bat_ps->dev.parent),
39					pdata->batt_aux) * pdata->batt_mult /
40					pdata->batt_div;
41}
42
43static unsigned long wm97xx_read_temp(struct power_supply *bat_ps)
44{
45	struct wm97xx_pdata *wmdata = bat_ps->dev.parent->platform_data;
46	struct wm97xx_batt_pdata *pdata = wmdata->batt_pdata;
47
48	return wm97xx_read_aux_adc(dev_get_drvdata(bat_ps->dev.parent),
49					pdata->temp_aux) * pdata->temp_mult /
50					pdata->temp_div;
51}
52
53static int wm97xx_bat_get_property(struct power_supply *bat_ps,
54			    enum power_supply_property psp,
55			    union power_supply_propval *val)
56{
57	struct wm97xx_pdata *wmdata = bat_ps->dev.parent->platform_data;
58	struct wm97xx_batt_pdata *pdata = wmdata->batt_pdata;
59
60	switch (psp) {
61	case POWER_SUPPLY_PROP_STATUS:
62		val->intval = bat_status;
63		break;
64	case POWER_SUPPLY_PROP_TECHNOLOGY:
65		val->intval = pdata->batt_tech;
66		break;
67	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
68		if (pdata->batt_aux >= 0)
69			val->intval = wm97xx_read_bat(bat_ps);
70		else
71			return -EINVAL;
72		break;
73	case POWER_SUPPLY_PROP_TEMP:
74		if (pdata->temp_aux >= 0)
75			val->intval = wm97xx_read_temp(bat_ps);
76		else
77			return -EINVAL;
78		break;
79	case POWER_SUPPLY_PROP_VOLTAGE_MAX:
80		if (pdata->max_voltage >= 0)
81			val->intval = pdata->max_voltage;
82		else
83			return -EINVAL;
84		break;
85	case POWER_SUPPLY_PROP_VOLTAGE_MIN:
86		if (pdata->min_voltage >= 0)
87			val->intval = pdata->min_voltage;
88		else
89			return -EINVAL;
90		break;
91	case POWER_SUPPLY_PROP_PRESENT:
92		val->intval = 1;
93		break;
94	default:
95		return -EINVAL;
96	}
97	return 0;
98}
99
100static void wm97xx_bat_external_power_changed(struct power_supply *bat_ps)
101{
102	schedule_work(&bat_work);
103}
104
105static void wm97xx_bat_update(struct power_supply *bat_ps)
106{
107	int old_status = bat_status;
108	struct wm97xx_pdata *wmdata = bat_ps->dev.parent->platform_data;
109	struct wm97xx_batt_pdata *pdata = wmdata->batt_pdata;
110
111	mutex_lock(&work_lock);
112
113	bat_status = (pdata->charge_gpio >= 0) ?
114			(gpio_get_value(pdata->charge_gpio) ?
115			POWER_SUPPLY_STATUS_DISCHARGING :
116			POWER_SUPPLY_STATUS_CHARGING) :
117			POWER_SUPPLY_STATUS_UNKNOWN;
118
119	if (old_status != bat_status) {
120		pr_debug("%s: %i -> %i\n", bat_ps->desc->name, old_status,
121					bat_status);
122		power_supply_changed(bat_ps);
123	}
124
125	mutex_unlock(&work_lock);
126}
127
128static struct power_supply *bat_psy;
129static struct power_supply_desc bat_psy_desc = {
130	.type			= POWER_SUPPLY_TYPE_BATTERY,
131	.get_property		= wm97xx_bat_get_property,
132	.external_power_changed = wm97xx_bat_external_power_changed,
133	.use_for_apm		= 1,
134};
135
136static void wm97xx_bat_work(struct work_struct *work)
137{
138	wm97xx_bat_update(bat_psy);
139}
140
141static irqreturn_t wm97xx_chrg_irq(int irq, void *data)
142{
143	schedule_work(&bat_work);
144	return IRQ_HANDLED;
145}
146
147#ifdef CONFIG_PM
148static int wm97xx_bat_suspend(struct device *dev)
149{
150	flush_work(&bat_work);
151	return 0;
152}
153
154static int wm97xx_bat_resume(struct device *dev)
155{
156	schedule_work(&bat_work);
157	return 0;
158}
159
160static const struct dev_pm_ops wm97xx_bat_pm_ops = {
161	.suspend	= wm97xx_bat_suspend,
162	.resume		= wm97xx_bat_resume,
163};
164#endif
165
166static int wm97xx_bat_probe(struct platform_device *dev)
167{
168	int ret = 0;
169	int props = 1;	/* POWER_SUPPLY_PROP_PRESENT */
170	int i = 0;
171	struct wm97xx_pdata *wmdata = dev->dev.platform_data;
172	struct wm97xx_batt_pdata *pdata;
173
174	if (!wmdata) {
175		dev_err(&dev->dev, "No platform data supplied\n");
176		return -EINVAL;
177	}
178
179	pdata = wmdata->batt_pdata;
180
181	if (dev->id != -1)
182		return -EINVAL;
183
184	if (!pdata) {
185		dev_err(&dev->dev, "No platform_data supplied\n");
186		return -EINVAL;
187	}
188
189	if (gpio_is_valid(pdata->charge_gpio)) {
190		ret = gpio_request(pdata->charge_gpio, "BATT CHRG");
191		if (ret)
192			goto err;
193		ret = gpio_direction_input(pdata->charge_gpio);
194		if (ret)
195			goto err2;
196		ret = request_irq(gpio_to_irq(pdata->charge_gpio),
197				wm97xx_chrg_irq, 0,
198				"AC Detect", dev);
199		if (ret)
200			goto err2;
201		props++;	/* POWER_SUPPLY_PROP_STATUS */
202	}
203
204	if (pdata->batt_tech >= 0)
205		props++;	/* POWER_SUPPLY_PROP_TECHNOLOGY */
206	if (pdata->temp_aux >= 0)
207		props++;	/* POWER_SUPPLY_PROP_TEMP */
208	if (pdata->batt_aux >= 0)
209		props++;	/* POWER_SUPPLY_PROP_VOLTAGE_NOW */
210	if (pdata->max_voltage >= 0)
211		props++;	/* POWER_SUPPLY_PROP_VOLTAGE_MAX */
212	if (pdata->min_voltage >= 0)
213		props++;	/* POWER_SUPPLY_PROP_VOLTAGE_MIN */
214
215	prop = kzalloc(props * sizeof(*prop), GFP_KERNEL);
216	if (!prop) {
217		ret = -ENOMEM;
218		goto err3;
219	}
220
221	prop[i++] = POWER_SUPPLY_PROP_PRESENT;
222	if (pdata->charge_gpio >= 0)
223		prop[i++] = POWER_SUPPLY_PROP_STATUS;
224	if (pdata->batt_tech >= 0)
225		prop[i++] = POWER_SUPPLY_PROP_TECHNOLOGY;
226	if (pdata->temp_aux >= 0)
227		prop[i++] = POWER_SUPPLY_PROP_TEMP;
228	if (pdata->batt_aux >= 0)
229		prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_NOW;
230	if (pdata->max_voltage >= 0)
231		prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MAX;
232	if (pdata->min_voltage >= 0)
233		prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MIN;
234
235	INIT_WORK(&bat_work, wm97xx_bat_work);
236
237	if (!pdata->batt_name) {
238		dev_info(&dev->dev, "Please consider setting proper battery "
239				"name in platform definition file, falling "
240				"back to name \"wm97xx-batt\"\n");
241		bat_psy_desc.name = "wm97xx-batt";
242	} else
243		bat_psy_desc.name = pdata->batt_name;
244
245	bat_psy_desc.properties = prop;
246	bat_psy_desc.num_properties = props;
247
248	bat_psy = power_supply_register(&dev->dev, &bat_psy_desc, NULL);
249	if (!IS_ERR(bat_psy)) {
250		schedule_work(&bat_work);
251	} else {
252		ret = PTR_ERR(bat_psy);
253		goto err4;
254	}
255
256	return 0;
257err4:
258	kfree(prop);
259err3:
260	if (gpio_is_valid(pdata->charge_gpio))
261		free_irq(gpio_to_irq(pdata->charge_gpio), dev);
262err2:
263	if (gpio_is_valid(pdata->charge_gpio))
264		gpio_free(pdata->charge_gpio);
265err:
266	return ret;
267}
268
269static int wm97xx_bat_remove(struct platform_device *dev)
270{
271	struct wm97xx_pdata *wmdata = dev->dev.platform_data;
272	struct wm97xx_batt_pdata *pdata = wmdata->batt_pdata;
273
274	if (pdata && gpio_is_valid(pdata->charge_gpio)) {
275		free_irq(gpio_to_irq(pdata->charge_gpio), dev);
276		gpio_free(pdata->charge_gpio);
277	}
278	cancel_work_sync(&bat_work);
279	power_supply_unregister(bat_psy);
280	kfree(prop);
281	return 0;
282}
283
284static struct platform_driver wm97xx_bat_driver = {
285	.driver	= {
286		.name	= "wm97xx-battery",
287#ifdef CONFIG_PM
288		.pm	= &wm97xx_bat_pm_ops,
289#endif
290	},
291	.probe		= wm97xx_bat_probe,
292	.remove		= wm97xx_bat_remove,
293};
294
295module_platform_driver(wm97xx_bat_driver);
296
297MODULE_LICENSE("GPL");
298MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
299MODULE_DESCRIPTION("WM97xx battery driver");
300