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
z2_read_bat(struct z2_charger * charger)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
z2_batt_get_property(struct power_supply * batt_ps,enum power_supply_property psp,union power_supply_propval * val)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
z2_batt_ext_power_changed(struct power_supply * batt_ps)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
z2_batt_update(struct z2_charger * charger)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
z2_batt_work(struct work_struct * work)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
z2_charge_switch_irq(int irq,void * devid)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
z2_batt_ps_init(struct z2_charger * charger,int props)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
z2_batt_probe(struct i2c_client * client,const struct i2c_device_id * id)183 static int 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 irq_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, 0,
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
z2_batt_remove(struct i2c_client * client)254 static int 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
z2_batt_suspend(struct device * dev)274 static int z2_batt_suspend(struct device *dev)
275 {
276 struct i2c_client *client = to_i2c_client(dev);
277 struct z2_charger *charger = i2c_get_clientdata(client);
278
279 flush_work(&charger->bat_work);
280 return 0;
281 }
282
z2_batt_resume(struct device * dev)283 static int z2_batt_resume(struct device *dev)
284 {
285 struct i2c_client *client = to_i2c_client(dev);
286 struct z2_charger *charger = i2c_get_clientdata(client);
287
288 schedule_work(&charger->bat_work);
289 return 0;
290 }
291
292 static const struct dev_pm_ops z2_battery_pm_ops = {
293 .suspend = z2_batt_suspend,
294 .resume = z2_batt_resume,
295 };
296
297 #define Z2_BATTERY_PM_OPS (&z2_battery_pm_ops)
298
299 #else
300 #define Z2_BATTERY_PM_OPS (NULL)
301 #endif
302
303 static const struct i2c_device_id z2_batt_id[] = {
304 { "aer915", 0 },
305 { }
306 };
307 MODULE_DEVICE_TABLE(i2c, z2_batt_id);
308
309 static struct i2c_driver z2_batt_driver = {
310 .driver = {
311 .name = "z2-battery",
312 .owner = THIS_MODULE,
313 .pm = Z2_BATTERY_PM_OPS
314 },
315 .probe = z2_batt_probe,
316 .remove = z2_batt_remove,
317 .id_table = z2_batt_id,
318 };
319 module_i2c_driver(z2_batt_driver);
320
321 MODULE_LICENSE("GPL");
322 MODULE_AUTHOR("Peter Edwards <sweetlilmre@gmail.com>");
323 MODULE_DESCRIPTION("Zipit Z2 battery driver");
324