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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/wm97xx_batt.h>
26 
27 static DEFINE_MUTEX(bat_lock);
28 static struct work_struct bat_work;
29 struct mutex work_lock;
30 static int bat_status = POWER_SUPPLY_STATUS_UNKNOWN;
31 static struct wm97xx_batt_info *pdata;
32 static enum power_supply_property *prop;
33 
wm97xx_read_bat(struct power_supply * bat_ps)34 static unsigned long wm97xx_read_bat(struct power_supply *bat_ps)
35 {
36 	return wm97xx_read_aux_adc(bat_ps->dev->parent->driver_data,
37 					pdata->batt_aux) * pdata->batt_mult /
38 					pdata->batt_div;
39 }
40 
wm97xx_read_temp(struct power_supply * bat_ps)41 static unsigned long wm97xx_read_temp(struct power_supply *bat_ps)
42 {
43 	return wm97xx_read_aux_adc(bat_ps->dev->parent->driver_data,
44 					pdata->temp_aux) * pdata->temp_mult /
45 					pdata->temp_div;
46 }
47 
wm97xx_bat_get_property(struct power_supply * bat_ps,enum power_supply_property psp,union power_supply_propval * val)48 static int wm97xx_bat_get_property(struct power_supply *bat_ps,
49 			    enum power_supply_property psp,
50 			    union power_supply_propval *val)
51 {
52 	switch (psp) {
53 	case POWER_SUPPLY_PROP_STATUS:
54 		val->intval = bat_status;
55 		break;
56 	case POWER_SUPPLY_PROP_TECHNOLOGY:
57 		val->intval = pdata->batt_tech;
58 		break;
59 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
60 		if (pdata->batt_aux >= 0)
61 			val->intval = wm97xx_read_bat(bat_ps);
62 		else
63 			return -EINVAL;
64 		break;
65 	case POWER_SUPPLY_PROP_TEMP:
66 		if (pdata->temp_aux >= 0)
67 			val->intval = wm97xx_read_temp(bat_ps);
68 		else
69 			return -EINVAL;
70 		break;
71 	case POWER_SUPPLY_PROP_VOLTAGE_MAX:
72 		if (pdata->max_voltage >= 0)
73 			val->intval = pdata->max_voltage;
74 		else
75 			return -EINVAL;
76 		break;
77 	case POWER_SUPPLY_PROP_VOLTAGE_MIN:
78 		if (pdata->min_voltage >= 0)
79 			val->intval = pdata->min_voltage;
80 		else
81 			return -EINVAL;
82 		break;
83 	case POWER_SUPPLY_PROP_PRESENT:
84 		val->intval = 1;
85 		break;
86 	default:
87 		return -EINVAL;
88 	}
89 	return 0;
90 }
91 
wm97xx_bat_external_power_changed(struct power_supply * bat_ps)92 static void wm97xx_bat_external_power_changed(struct power_supply *bat_ps)
93 {
94 	schedule_work(&bat_work);
95 }
96 
wm97xx_bat_update(struct power_supply * bat_ps)97 static void wm97xx_bat_update(struct power_supply *bat_ps)
98 {
99 	int old_status = bat_status;
100 
101 	mutex_lock(&work_lock);
102 
103 	bat_status = (pdata->charge_gpio >= 0) ?
104 			(gpio_get_value(pdata->charge_gpio) ?
105 			POWER_SUPPLY_STATUS_DISCHARGING :
106 			POWER_SUPPLY_STATUS_CHARGING) :
107 			POWER_SUPPLY_STATUS_UNKNOWN;
108 
109 	if (old_status != bat_status) {
110 		pr_debug("%s: %i -> %i\n", bat_ps->name, old_status,
111 					bat_status);
112 		power_supply_changed(bat_ps);
113 	}
114 
115 	mutex_unlock(&work_lock);
116 }
117 
118 static struct power_supply bat_ps = {
119 	.type			= POWER_SUPPLY_TYPE_BATTERY,
120 	.get_property		= wm97xx_bat_get_property,
121 	.external_power_changed = wm97xx_bat_external_power_changed,
122 	.use_for_apm		= 1,
123 };
124 
wm97xx_bat_work(struct work_struct * work)125 static void wm97xx_bat_work(struct work_struct *work)
126 {
127 	wm97xx_bat_update(&bat_ps);
128 }
129 
130 #ifdef CONFIG_PM
wm97xx_bat_suspend(struct platform_device * dev,pm_message_t state)131 static int wm97xx_bat_suspend(struct platform_device *dev, pm_message_t state)
132 {
133 	flush_scheduled_work();
134 	return 0;
135 }
136 
wm97xx_bat_resume(struct platform_device * dev)137 static int wm97xx_bat_resume(struct platform_device *dev)
138 {
139 	schedule_work(&bat_work);
140 	return 0;
141 }
142 #else
143 #define wm97xx_bat_suspend NULL
144 #define wm97xx_bat_resume NULL
145 #endif
146 
wm97xx_bat_probe(struct platform_device * dev)147 static int __devinit wm97xx_bat_probe(struct platform_device *dev)
148 {
149 	int ret = 0;
150 	int props = 1;	/* POWER_SUPPLY_PROP_PRESENT */
151 	int i = 0;
152 
153 	if (dev->id != -1)
154 		return -EINVAL;
155 
156 	mutex_init(&work_lock);
157 
158 	if (!pdata) {
159 		dev_err(&dev->dev, "Please use wm97xx_bat_set_pdata\n");
160 		return -EINVAL;
161 	}
162 
163 	if (pdata->charge_gpio >= 0 && gpio_is_valid(pdata->charge_gpio)) {
164 		ret = gpio_request(pdata->charge_gpio, "BATT CHRG");
165 		if (ret)
166 			goto err;
167 		ret = gpio_direction_input(pdata->charge_gpio);
168 		if (ret)
169 			goto err2;
170 		props++;	/* POWER_SUPPLY_PROP_STATUS */
171 	}
172 
173 	if (pdata->batt_tech >= 0)
174 		props++;	/* POWER_SUPPLY_PROP_TECHNOLOGY */
175 	if (pdata->temp_aux >= 0)
176 		props++;	/* POWER_SUPPLY_PROP_TEMP */
177 	if (pdata->batt_aux >= 0)
178 		props++;	/* POWER_SUPPLY_PROP_VOLTAGE_NOW */
179 	if (pdata->max_voltage >= 0)
180 		props++;	/* POWER_SUPPLY_PROP_VOLTAGE_MAX */
181 	if (pdata->min_voltage >= 0)
182 		props++;	/* POWER_SUPPLY_PROP_VOLTAGE_MIN */
183 
184 	prop = kzalloc(props * sizeof(*prop), GFP_KERNEL);
185 	if (!prop)
186 		goto err2;
187 
188 	prop[i++] = POWER_SUPPLY_PROP_PRESENT;
189 	if (pdata->charge_gpio >= 0)
190 		prop[i++] = POWER_SUPPLY_PROP_STATUS;
191 	if (pdata->batt_tech >= 0)
192 		prop[i++] = POWER_SUPPLY_PROP_TECHNOLOGY;
193 	if (pdata->temp_aux >= 0)
194 		prop[i++] = POWER_SUPPLY_PROP_TEMP;
195 	if (pdata->batt_aux >= 0)
196 		prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_NOW;
197 	if (pdata->max_voltage >= 0)
198 		prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MAX;
199 	if (pdata->min_voltage >= 0)
200 		prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MIN;
201 
202 	INIT_WORK(&bat_work, wm97xx_bat_work);
203 
204 	if (!pdata->batt_name) {
205 		dev_info(&dev->dev, "Please consider setting proper battery "
206 				"name in platform definition file, falling "
207 				"back to name \"wm97xx-batt\"\n");
208 		bat_ps.name = "wm97xx-batt";
209 	} else
210 		bat_ps.name = pdata->batt_name;
211 
212 	bat_ps.properties = prop;
213 	bat_ps.num_properties = props;
214 
215 	ret = power_supply_register(&dev->dev, &bat_ps);
216 	if (!ret)
217 		schedule_work(&bat_work);
218 	else
219 		goto err3;
220 
221 	return 0;
222 err3:
223 	kfree(prop);
224 err2:
225 	gpio_free(pdata->charge_gpio);
226 err:
227 	return ret;
228 }
229 
wm97xx_bat_remove(struct platform_device * dev)230 static int __devexit wm97xx_bat_remove(struct platform_device *dev)
231 {
232 	if (pdata && pdata->charge_gpio && pdata->charge_gpio >= 0)
233 		gpio_free(pdata->charge_gpio);
234 	flush_scheduled_work();
235 	power_supply_unregister(&bat_ps);
236 	kfree(prop);
237 	return 0;
238 }
239 
240 static struct platform_driver wm97xx_bat_driver = {
241 	.driver	= {
242 		.name	= "wm97xx-battery",
243 		.owner	= THIS_MODULE,
244 	},
245 	.probe		= wm97xx_bat_probe,
246 	.remove		= __devexit_p(wm97xx_bat_remove),
247 	.suspend	= wm97xx_bat_suspend,
248 	.resume		= wm97xx_bat_resume,
249 };
250 
wm97xx_bat_init(void)251 static int __init wm97xx_bat_init(void)
252 {
253 	return platform_driver_register(&wm97xx_bat_driver);
254 }
255 
wm97xx_bat_exit(void)256 static void __exit wm97xx_bat_exit(void)
257 {
258 	platform_driver_unregister(&wm97xx_bat_driver);
259 }
260 
wm97xx_bat_set_pdata(struct wm97xx_batt_info * data)261 void __init wm97xx_bat_set_pdata(struct wm97xx_batt_info *data)
262 {
263 	pdata = data;
264 }
265 EXPORT_SYMBOL_GPL(wm97xx_bat_set_pdata);
266 
267 module_init(wm97xx_bat_init);
268 module_exit(wm97xx_bat_exit);
269 
270 MODULE_LICENSE("GPL");
271 MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
272 MODULE_DESCRIPTION("WM97xx battery driver");
273