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