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 power_supply_desc batt_ps_desc;
29 struct mutex work_lock;
30 struct work_struct bat_work;
31 };
32
z2_read_bat(struct z2_charger * charger)33 static unsigned long z2_read_bat(struct z2_charger *charger)
34 {
35 int data;
36 data = i2c_smbus_read_byte_data(charger->client,
37 charger->info->batt_I2C_reg);
38 if (data < 0)
39 return 0;
40
41 return data * charger->info->batt_mult / charger->info->batt_div;
42 }
43
z2_batt_get_property(struct power_supply * batt_ps,enum power_supply_property psp,union power_supply_propval * val)44 static int z2_batt_get_property(struct power_supply *batt_ps,
45 enum power_supply_property psp,
46 union power_supply_propval *val)
47 {
48 struct z2_charger *charger = power_supply_get_drvdata(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 = power_supply_get_drvdata(batt_ps);
89
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->desc->name,
110 old_status,
111 charger->bat_status);
112 power_supply_changed(charger->batt_ps);
113 }
114
115 mutex_unlock(&charger->work_lock);
116 }
117
z2_batt_work(struct work_struct * work)118 static void z2_batt_work(struct work_struct *work)
119 {
120 struct z2_charger *charger;
121 charger = container_of(work, struct z2_charger, bat_work);
122 z2_batt_update(charger);
123 }
124
z2_charge_switch_irq(int irq,void * devid)125 static irqreturn_t z2_charge_switch_irq(int irq, void *devid)
126 {
127 struct z2_charger *charger = devid;
128 schedule_work(&charger->bat_work);
129 return IRQ_HANDLED;
130 }
131
z2_batt_ps_init(struct z2_charger * charger,int props)132 static int z2_batt_ps_init(struct z2_charger *charger, int props)
133 {
134 int i = 0;
135 enum power_supply_property *prop;
136 struct z2_battery_info *info = charger->info;
137
138 if (info->charge_gpio >= 0)
139 props++; /* POWER_SUPPLY_PROP_STATUS */
140 if (info->batt_tech >= 0)
141 props++; /* POWER_SUPPLY_PROP_TECHNOLOGY */
142 if (info->batt_I2C_reg >= 0)
143 props++; /* POWER_SUPPLY_PROP_VOLTAGE_NOW */
144 if (info->max_voltage >= 0)
145 props++; /* POWER_SUPPLY_PROP_VOLTAGE_MAX */
146 if (info->min_voltage >= 0)
147 props++; /* POWER_SUPPLY_PROP_VOLTAGE_MIN */
148
149 prop = kcalloc(props, sizeof(*prop), GFP_KERNEL);
150 if (!prop)
151 return -ENOMEM;
152
153 prop[i++] = POWER_SUPPLY_PROP_PRESENT;
154 if (info->charge_gpio >= 0)
155 prop[i++] = POWER_SUPPLY_PROP_STATUS;
156 if (info->batt_tech >= 0)
157 prop[i++] = POWER_SUPPLY_PROP_TECHNOLOGY;
158 if (info->batt_I2C_reg >= 0)
159 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_NOW;
160 if (info->max_voltage >= 0)
161 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MAX;
162 if (info->min_voltage >= 0)
163 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MIN;
164
165 if (!info->batt_name) {
166 dev_info(&charger->client->dev,
167 "Please consider setting proper battery "
168 "name in platform definition file, falling "
169 "back to name \" Z2_DEFAULT_NAME \"\n");
170 charger->batt_ps_desc.name = Z2_DEFAULT_NAME;
171 } else
172 charger->batt_ps_desc.name = info->batt_name;
173
174 charger->batt_ps_desc.properties = prop;
175 charger->batt_ps_desc.num_properties = props;
176 charger->batt_ps_desc.type = POWER_SUPPLY_TYPE_BATTERY;
177 charger->batt_ps_desc.get_property = z2_batt_get_property;
178 charger->batt_ps_desc.external_power_changed =
179 z2_batt_ext_power_changed;
180 charger->batt_ps_desc.use_for_apm = 1;
181
182 return 0;
183 }
184
z2_batt_probe(struct i2c_client * client,const struct i2c_device_id * id)185 static int z2_batt_probe(struct i2c_client *client,
186 const struct i2c_device_id *id)
187 {
188 int ret = 0;
189 int props = 1; /* POWER_SUPPLY_PROP_PRESENT */
190 struct z2_charger *charger;
191 struct z2_battery_info *info = client->dev.platform_data;
192 struct power_supply_config psy_cfg = {};
193
194 if (info == NULL) {
195 dev_err(&client->dev,
196 "Please set platform device platform_data"
197 " to a valid z2_battery_info pointer!\n");
198 return -EINVAL;
199 }
200
201 charger = kzalloc(sizeof(*charger), GFP_KERNEL);
202 if (charger == NULL)
203 return -ENOMEM;
204
205 charger->bat_status = POWER_SUPPLY_STATUS_UNKNOWN;
206 charger->info = info;
207 charger->client = client;
208 i2c_set_clientdata(client, charger);
209 psy_cfg.drv_data = 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 irq_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, 0,
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 charger->batt_ps = power_supply_register(&client->dev,
238 &charger->batt_ps_desc,
239 &psy_cfg);
240 if (IS_ERR(charger->batt_ps)) {
241 ret = PTR_ERR(charger->batt_ps);
242 goto err4;
243 }
244
245 schedule_work(&charger->bat_work);
246
247 return 0;
248
249 err4:
250 kfree(charger->batt_ps_desc.properties);
251 err3:
252 if (info->charge_gpio >= 0 && gpio_is_valid(info->charge_gpio))
253 free_irq(gpio_to_irq(info->charge_gpio), charger);
254 err2:
255 if (info->charge_gpio >= 0 && gpio_is_valid(info->charge_gpio))
256 gpio_free(info->charge_gpio);
257 err:
258 kfree(charger);
259 return ret;
260 }
261
z2_batt_remove(struct i2c_client * client)262 static int z2_batt_remove(struct i2c_client *client)
263 {
264 struct z2_charger *charger = i2c_get_clientdata(client);
265 struct z2_battery_info *info = charger->info;
266
267 cancel_work_sync(&charger->bat_work);
268 power_supply_unregister(charger->batt_ps);
269
270 kfree(charger->batt_ps_desc.properties);
271 if (info->charge_gpio >= 0 && gpio_is_valid(info->charge_gpio)) {
272 free_irq(gpio_to_irq(info->charge_gpio), charger);
273 gpio_free(info->charge_gpio);
274 }
275
276 kfree(charger);
277
278 return 0;
279 }
280
281 #ifdef CONFIG_PM
z2_batt_suspend(struct device * dev)282 static int z2_batt_suspend(struct device *dev)
283 {
284 struct i2c_client *client = to_i2c_client(dev);
285 struct z2_charger *charger = i2c_get_clientdata(client);
286
287 flush_work(&charger->bat_work);
288 return 0;
289 }
290
z2_batt_resume(struct device * dev)291 static int z2_batt_resume(struct device *dev)
292 {
293 struct i2c_client *client = to_i2c_client(dev);
294 struct z2_charger *charger = i2c_get_clientdata(client);
295
296 schedule_work(&charger->bat_work);
297 return 0;
298 }
299
300 static const struct dev_pm_ops z2_battery_pm_ops = {
301 .suspend = z2_batt_suspend,
302 .resume = z2_batt_resume,
303 };
304
305 #define Z2_BATTERY_PM_OPS (&z2_battery_pm_ops)
306
307 #else
308 #define Z2_BATTERY_PM_OPS (NULL)
309 #endif
310
311 static const struct i2c_device_id z2_batt_id[] = {
312 { "aer915", 0 },
313 { }
314 };
315 MODULE_DEVICE_TABLE(i2c, z2_batt_id);
316
317 static struct i2c_driver z2_batt_driver = {
318 .driver = {
319 .name = "z2-battery",
320 .pm = Z2_BATTERY_PM_OPS
321 },
322 .probe = z2_batt_probe,
323 .remove = z2_batt_remove,
324 .id_table = z2_batt_id,
325 };
326 module_i2c_driver(z2_batt_driver);
327
328 MODULE_LICENSE("GPL");
329 MODULE_AUTHOR("Peter Edwards <sweetlilmre@gmail.com>");
330 MODULE_DESCRIPTION("Zipit Z2 battery driver");
331