2a9ab89f83b8af99264495663516694fc2afee25
[linux-2.6.git] / drivers / power / z2_battery.c
1 /*
2  * Battery measurement code for Zipit Z2
3  *
4  * Copyright (C) 2009 Peter Edwards <sweetlilmre@gmail.com>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  *
10  */
11
12 #include <linux/module.h>
13 #include <linux/gpio.h>
14 #include <linux/i2c.h>
15 #include <linux/interrupt.h>
16 #include <linux/irq.h>
17 #include <linux/power_supply.h>
18 #include <linux/slab.h>
19 #include <linux/z2_battery.h>
20
21 #define Z2_DEFAULT_NAME "Z2"
22
23 struct z2_charger {
24         struct z2_battery_info  *info;
25         int                     bat_status;
26         struct i2c_client       *client;
27         struct power_supply     batt_ps;
28         struct mutex            work_lock;
29         struct work_struct      bat_work;
30 };
31
32 static unsigned long z2_read_bat(struct z2_charger *charger)
33 {
34         int data;
35         data = i2c_smbus_read_byte_data(charger->client,
36                                         charger->info->batt_I2C_reg);
37         if (data < 0)
38                 return 0;
39
40         return data * charger->info->batt_mult / charger->info->batt_div;
41 }
42
43 static int z2_batt_get_property(struct power_supply *batt_ps,
44                             enum power_supply_property psp,
45                             union power_supply_propval *val)
46 {
47         struct z2_charger *charger = container_of(batt_ps, struct z2_charger,
48                                                 batt_ps);
49         struct z2_battery_info *info = charger->info;
50
51         switch (psp) {
52         case POWER_SUPPLY_PROP_STATUS:
53                 val->intval = charger->bat_status;
54                 break;
55         case POWER_SUPPLY_PROP_TECHNOLOGY:
56                 val->intval = info->batt_tech;
57                 break;
58         case POWER_SUPPLY_PROP_VOLTAGE_NOW:
59                 if (info->batt_I2C_reg >= 0)
60                         val->intval = z2_read_bat(charger);
61                 else
62                         return -EINVAL;
63                 break;
64         case POWER_SUPPLY_PROP_VOLTAGE_MAX:
65                 if (info->max_voltage >= 0)
66                         val->intval = info->max_voltage;
67                 else
68                         return -EINVAL;
69                 break;
70         case POWER_SUPPLY_PROP_VOLTAGE_MIN:
71                 if (info->min_voltage >= 0)
72                         val->intval = info->min_voltage;
73                 else
74                         return -EINVAL;
75                 break;
76         case POWER_SUPPLY_PROP_PRESENT:
77                 val->intval = 1;
78                 break;
79         default:
80                 return -EINVAL;
81         }
82
83         return 0;
84 }
85
86 static void z2_batt_ext_power_changed(struct power_supply *batt_ps)
87 {
88         struct z2_charger *charger = container_of(batt_ps, struct z2_charger,
89                                                 batt_ps);
90         schedule_work(&charger->bat_work);
91 }
92
93 static void z2_batt_update(struct z2_charger *charger)
94 {
95         int old_status = charger->bat_status;
96         struct z2_battery_info *info;
97
98         info = charger->info;
99
100         mutex_lock(&charger->work_lock);
101
102         charger->bat_status = (info->charge_gpio >= 0) ?
103                 (gpio_get_value(info->charge_gpio) ?
104                 POWER_SUPPLY_STATUS_CHARGING :
105                 POWER_SUPPLY_STATUS_DISCHARGING) :
106                 POWER_SUPPLY_STATUS_UNKNOWN;
107
108         if (old_status != charger->bat_status) {
109                 pr_debug("%s: %i -> %i\n", charger->batt_ps.name, old_status,
110                         charger->bat_status);
111                 power_supply_changed(&charger->batt_ps);
112         }
113
114         mutex_unlock(&charger->work_lock);
115 }
116
117 static void z2_batt_work(struct work_struct *work)
118 {
119         struct z2_charger *charger;
120         charger = container_of(work, struct z2_charger, bat_work);
121         z2_batt_update(charger);
122 }
123
124 static irqreturn_t z2_charge_switch_irq(int irq, void *devid)
125 {
126         struct z2_charger *charger = devid;
127         schedule_work(&charger->bat_work);
128         return IRQ_HANDLED;
129 }
130
131 static int z2_batt_ps_init(struct z2_charger *charger, int props)
132 {
133         int i = 0;
134         enum power_supply_property *prop;
135         struct z2_battery_info *info = charger->info;
136
137         if (info->charge_gpio >= 0)
138                 props++;        /* POWER_SUPPLY_PROP_STATUS */
139         if (info->batt_tech >= 0)
140                 props++;        /* POWER_SUPPLY_PROP_TECHNOLOGY */
141         if (info->batt_I2C_reg >= 0)
142                 props++;        /* POWER_SUPPLY_PROP_VOLTAGE_NOW */
143         if (info->max_voltage >= 0)
144                 props++;        /* POWER_SUPPLY_PROP_VOLTAGE_MAX */
145         if (info->min_voltage >= 0)
146                 props++;        /* POWER_SUPPLY_PROP_VOLTAGE_MIN */
147
148         prop = kzalloc(props * sizeof(*prop), GFP_KERNEL);
149         if (!prop)
150                 return -ENOMEM;
151
152         prop[i++] = POWER_SUPPLY_PROP_PRESENT;
153         if (info->charge_gpio >= 0)
154                 prop[i++] = POWER_SUPPLY_PROP_STATUS;
155         if (info->batt_tech >= 0)
156                 prop[i++] = POWER_SUPPLY_PROP_TECHNOLOGY;
157         if (info->batt_I2C_reg >= 0)
158                 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_NOW;
159         if (info->max_voltage >= 0)
160                 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MAX;
161         if (info->min_voltage >= 0)
162                 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MIN;
163
164         if (!info->batt_name) {
165                 dev_info(&charger->client->dev,
166                                 "Please consider setting proper battery "
167                                 "name in platform definition file, falling "
168                                 "back to name \" Z2_DEFAULT_NAME \"\n");
169                 charger->batt_ps.name = Z2_DEFAULT_NAME;
170         } else
171                 charger->batt_ps.name = info->batt_name;
172
173         charger->batt_ps.properties             = prop;
174         charger->batt_ps.num_properties         = props;
175         charger->batt_ps.type                   = POWER_SUPPLY_TYPE_BATTERY;
176         charger->batt_ps.get_property           = z2_batt_get_property;
177         charger->batt_ps.external_power_changed = z2_batt_ext_power_changed;
178         charger->batt_ps.use_for_apm            = 1;
179
180         return 0;
181 }
182
183 static int __devinit z2_batt_probe(struct i2c_client *client,
184                                 const struct i2c_device_id *id)
185 {
186         int ret = 0;
187         int props = 1;  /* POWER_SUPPLY_PROP_PRESENT */
188         struct z2_charger *charger;
189         struct z2_battery_info *info = client->dev.platform_data;
190
191         if (info == NULL) {
192                 dev_err(&client->dev,
193                         "Please set platform device platform_data"
194                         " to a valid z2_battery_info pointer!\n");
195                 return -EINVAL;
196         }
197
198         charger = kzalloc(sizeof(*charger), GFP_KERNEL);
199         if (charger == NULL)
200                 return -ENOMEM;
201
202         charger->bat_status = POWER_SUPPLY_STATUS_UNKNOWN;
203         charger->info = info;
204         charger->client = client;
205         i2c_set_clientdata(client, charger);
206
207         mutex_init(&charger->work_lock);
208
209         if (info->charge_gpio >= 0 && gpio_is_valid(info->charge_gpio)) {
210                 ret = gpio_request(info->charge_gpio, "BATT CHRG");
211                 if (ret)
212                         goto err;
213
214                 ret = gpio_direction_input(info->charge_gpio);
215                 if (ret)
216                         goto err2;
217
218                 set_irq_type(gpio_to_irq(info->charge_gpio),
219                                 IRQ_TYPE_EDGE_BOTH);
220                 ret = request_irq(gpio_to_irq(info->charge_gpio),
221                                 z2_charge_switch_irq, IRQF_DISABLED,
222                                 "AC Detect", charger);
223                 if (ret)
224                         goto err3;
225         }
226
227         ret = z2_batt_ps_init(charger, props);
228         if (ret)
229                 goto err3;
230
231         INIT_WORK(&charger->bat_work, z2_batt_work);
232
233         ret = power_supply_register(&client->dev, &charger->batt_ps);
234         if (ret)
235                 goto err4;
236
237         schedule_work(&charger->bat_work);
238
239         return 0;
240
241 err4:
242         kfree(charger->batt_ps.properties);
243 err3:
244         if (info->charge_gpio >= 0 && gpio_is_valid(info->charge_gpio))
245                 free_irq(gpio_to_irq(info->charge_gpio), charger);
246 err2:
247         if (info->charge_gpio >= 0 && gpio_is_valid(info->charge_gpio))
248                 gpio_free(info->charge_gpio);
249 err:
250         kfree(charger);
251         return ret;
252 }
253
254 static int __devexit z2_batt_remove(struct i2c_client *client)
255 {
256         struct z2_charger *charger = i2c_get_clientdata(client);
257         struct z2_battery_info *info = charger->info;
258
259         cancel_work_sync(&charger->bat_work);
260         power_supply_unregister(&charger->batt_ps);
261
262         kfree(charger->batt_ps.properties);
263         if (info->charge_gpio >= 0 && gpio_is_valid(info->charge_gpio)) {
264                 free_irq(gpio_to_irq(info->charge_gpio), charger);
265                 gpio_free(info->charge_gpio);
266         }
267
268         kfree(charger);
269
270         return 0;
271 }
272
273 #ifdef CONFIG_PM
274 static int z2_batt_suspend(struct i2c_client *client, pm_message_t state)
275 {
276         struct z2_charger *charger = i2c_get_clientdata(client);
277
278         flush_work_sync(&charger->bat_work);
279         return 0;
280 }
281
282 static int z2_batt_resume(struct i2c_client *client)
283 {
284         struct z2_charger *charger = i2c_get_clientdata(client);
285
286         schedule_work(&charger->bat_work);
287         return 0;
288 }
289 #else
290 #define z2_batt_suspend NULL
291 #define z2_batt_resume NULL
292 #endif
293
294 static const struct i2c_device_id z2_batt_id[] = {
295         { "aer915", 0 },
296         { }
297 };
298 MODULE_DEVICE_TABLE(i2c, z2_batt_id);
299
300 static struct i2c_driver z2_batt_driver = {
301         .driver = {
302                 .name   = "z2-battery",
303                 .owner  = THIS_MODULE,
304         },
305         .probe          = z2_batt_probe,
306         .remove         = z2_batt_remove,
307         .suspend        = z2_batt_suspend,
308         .resume         = z2_batt_resume,
309         .id_table       = z2_batt_id,
310 };
311
312 static int __init z2_batt_init(void)
313 {
314         return i2c_add_driver(&z2_batt_driver);
315 }
316
317 static void __exit z2_batt_exit(void)
318 {
319         i2c_del_driver(&z2_batt_driver);
320 }
321
322 module_init(z2_batt_init);
323 module_exit(z2_batt_exit);
324
325 MODULE_LICENSE("GPL");
326 MODULE_AUTHOR("Peter Edwards <sweetlilmre@gmail.com>");
327 MODULE_DESCRIPTION("Zipit Z2 battery driver");