Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs...
[linux-2.6] / drivers / power / wm97xx_battery.c
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
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
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
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
92 static void wm97xx_bat_external_power_changed(struct power_supply *bat_ps)
93 {
94         schedule_work(&bat_work);
95 }
96
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
125 static void wm97xx_bat_work(struct work_struct *work)
126 {
127         wm97xx_bat_update(&bat_ps);
128 }
129
130 #ifdef CONFIG_PM
131 static int wm97xx_bat_suspend(struct platform_device *dev, pm_message_t state)
132 {
133         flush_scheduled_work();
134         return 0;
135 }
136
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
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
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
251 static int __init wm97xx_bat_init(void)
252 {
253         return platform_driver_register(&wm97xx_bat_driver);
254 }
255
256 static void __exit wm97xx_bat_exit(void)
257 {
258         platform_driver_unregister(&wm97xx_bat_driver);
259 }
260
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");