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/irq.h>
26 #include <linux/slab.h>
27
28 static struct work_struct bat_work;
29 static DEFINE_MUTEX(work_lock);
30 static int bat_status = POWER_SUPPLY_STATUS_UNKNOWN;
31 static enum power_supply_property *prop;
32
wm97xx_read_bat(struct power_supply * bat_ps)33 static unsigned long wm97xx_read_bat(struct power_supply *bat_ps)
34 {
35 struct wm97xx_pdata *wmdata = bat_ps->dev.parent->platform_data;
36 struct wm97xx_batt_pdata *pdata = wmdata->batt_pdata;
37
38 return wm97xx_read_aux_adc(dev_get_drvdata(bat_ps->dev.parent),
39 pdata->batt_aux) * pdata->batt_mult /
40 pdata->batt_div;
41 }
42
wm97xx_read_temp(struct power_supply * bat_ps)43 static unsigned long wm97xx_read_temp(struct power_supply *bat_ps)
44 {
45 struct wm97xx_pdata *wmdata = bat_ps->dev.parent->platform_data;
46 struct wm97xx_batt_pdata *pdata = wmdata->batt_pdata;
47
48 return wm97xx_read_aux_adc(dev_get_drvdata(bat_ps->dev.parent),
49 pdata->temp_aux) * pdata->temp_mult /
50 pdata->temp_div;
51 }
52
wm97xx_bat_get_property(struct power_supply * bat_ps,enum power_supply_property psp,union power_supply_propval * val)53 static int wm97xx_bat_get_property(struct power_supply *bat_ps,
54 enum power_supply_property psp,
55 union power_supply_propval *val)
56 {
57 struct wm97xx_pdata *wmdata = bat_ps->dev.parent->platform_data;
58 struct wm97xx_batt_pdata *pdata = wmdata->batt_pdata;
59
60 switch (psp) {
61 case POWER_SUPPLY_PROP_STATUS:
62 val->intval = bat_status;
63 break;
64 case POWER_SUPPLY_PROP_TECHNOLOGY:
65 val->intval = pdata->batt_tech;
66 break;
67 case POWER_SUPPLY_PROP_VOLTAGE_NOW:
68 if (pdata->batt_aux >= 0)
69 val->intval = wm97xx_read_bat(bat_ps);
70 else
71 return -EINVAL;
72 break;
73 case POWER_SUPPLY_PROP_TEMP:
74 if (pdata->temp_aux >= 0)
75 val->intval = wm97xx_read_temp(bat_ps);
76 else
77 return -EINVAL;
78 break;
79 case POWER_SUPPLY_PROP_VOLTAGE_MAX:
80 if (pdata->max_voltage >= 0)
81 val->intval = pdata->max_voltage;
82 else
83 return -EINVAL;
84 break;
85 case POWER_SUPPLY_PROP_VOLTAGE_MIN:
86 if (pdata->min_voltage >= 0)
87 val->intval = pdata->min_voltage;
88 else
89 return -EINVAL;
90 break;
91 case POWER_SUPPLY_PROP_PRESENT:
92 val->intval = 1;
93 break;
94 default:
95 return -EINVAL;
96 }
97 return 0;
98 }
99
wm97xx_bat_external_power_changed(struct power_supply * bat_ps)100 static void wm97xx_bat_external_power_changed(struct power_supply *bat_ps)
101 {
102 schedule_work(&bat_work);
103 }
104
wm97xx_bat_update(struct power_supply * bat_ps)105 static void wm97xx_bat_update(struct power_supply *bat_ps)
106 {
107 int old_status = bat_status;
108 struct wm97xx_pdata *wmdata = bat_ps->dev.parent->platform_data;
109 struct wm97xx_batt_pdata *pdata = wmdata->batt_pdata;
110
111 mutex_lock(&work_lock);
112
113 bat_status = (pdata->charge_gpio >= 0) ?
114 (gpio_get_value(pdata->charge_gpio) ?
115 POWER_SUPPLY_STATUS_DISCHARGING :
116 POWER_SUPPLY_STATUS_CHARGING) :
117 POWER_SUPPLY_STATUS_UNKNOWN;
118
119 if (old_status != bat_status) {
120 pr_debug("%s: %i -> %i\n", bat_ps->desc->name, old_status,
121 bat_status);
122 power_supply_changed(bat_ps);
123 }
124
125 mutex_unlock(&work_lock);
126 }
127
128 static struct power_supply *bat_psy;
129 static struct power_supply_desc bat_psy_desc = {
130 .type = POWER_SUPPLY_TYPE_BATTERY,
131 .get_property = wm97xx_bat_get_property,
132 .external_power_changed = wm97xx_bat_external_power_changed,
133 .use_for_apm = 1,
134 };
135
wm97xx_bat_work(struct work_struct * work)136 static void wm97xx_bat_work(struct work_struct *work)
137 {
138 wm97xx_bat_update(bat_psy);
139 }
140
wm97xx_chrg_irq(int irq,void * data)141 static irqreturn_t wm97xx_chrg_irq(int irq, void *data)
142 {
143 schedule_work(&bat_work);
144 return IRQ_HANDLED;
145 }
146
147 #ifdef CONFIG_PM
wm97xx_bat_suspend(struct device * dev)148 static int wm97xx_bat_suspend(struct device *dev)
149 {
150 flush_work(&bat_work);
151 return 0;
152 }
153
wm97xx_bat_resume(struct device * dev)154 static int wm97xx_bat_resume(struct device *dev)
155 {
156 schedule_work(&bat_work);
157 return 0;
158 }
159
160 static const struct dev_pm_ops wm97xx_bat_pm_ops = {
161 .suspend = wm97xx_bat_suspend,
162 .resume = wm97xx_bat_resume,
163 };
164 #endif
165
wm97xx_bat_probe(struct platform_device * dev)166 static int wm97xx_bat_probe(struct platform_device *dev)
167 {
168 int ret = 0;
169 int props = 1; /* POWER_SUPPLY_PROP_PRESENT */
170 int i = 0;
171 struct wm97xx_pdata *wmdata = dev->dev.platform_data;
172 struct wm97xx_batt_pdata *pdata;
173
174 if (!wmdata) {
175 dev_err(&dev->dev, "No platform data supplied\n");
176 return -EINVAL;
177 }
178
179 pdata = wmdata->batt_pdata;
180
181 if (dev->id != -1)
182 return -EINVAL;
183
184 if (!pdata) {
185 dev_err(&dev->dev, "No platform_data supplied\n");
186 return -EINVAL;
187 }
188
189 if (gpio_is_valid(pdata->charge_gpio)) {
190 ret = gpio_request(pdata->charge_gpio, "BATT CHRG");
191 if (ret)
192 goto err;
193 ret = gpio_direction_input(pdata->charge_gpio);
194 if (ret)
195 goto err2;
196 ret = request_irq(gpio_to_irq(pdata->charge_gpio),
197 wm97xx_chrg_irq, 0,
198 "AC Detect", dev);
199 if (ret)
200 goto err2;
201 props++; /* POWER_SUPPLY_PROP_STATUS */
202 }
203
204 if (pdata->batt_tech >= 0)
205 props++; /* POWER_SUPPLY_PROP_TECHNOLOGY */
206 if (pdata->temp_aux >= 0)
207 props++; /* POWER_SUPPLY_PROP_TEMP */
208 if (pdata->batt_aux >= 0)
209 props++; /* POWER_SUPPLY_PROP_VOLTAGE_NOW */
210 if (pdata->max_voltage >= 0)
211 props++; /* POWER_SUPPLY_PROP_VOLTAGE_MAX */
212 if (pdata->min_voltage >= 0)
213 props++; /* POWER_SUPPLY_PROP_VOLTAGE_MIN */
214
215 prop = kzalloc(props * sizeof(*prop), GFP_KERNEL);
216 if (!prop) {
217 ret = -ENOMEM;
218 goto err3;
219 }
220
221 prop[i++] = POWER_SUPPLY_PROP_PRESENT;
222 if (pdata->charge_gpio >= 0)
223 prop[i++] = POWER_SUPPLY_PROP_STATUS;
224 if (pdata->batt_tech >= 0)
225 prop[i++] = POWER_SUPPLY_PROP_TECHNOLOGY;
226 if (pdata->temp_aux >= 0)
227 prop[i++] = POWER_SUPPLY_PROP_TEMP;
228 if (pdata->batt_aux >= 0)
229 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_NOW;
230 if (pdata->max_voltage >= 0)
231 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MAX;
232 if (pdata->min_voltage >= 0)
233 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MIN;
234
235 INIT_WORK(&bat_work, wm97xx_bat_work);
236
237 if (!pdata->batt_name) {
238 dev_info(&dev->dev, "Please consider setting proper battery "
239 "name in platform definition file, falling "
240 "back to name \"wm97xx-batt\"\n");
241 bat_psy_desc.name = "wm97xx-batt";
242 } else
243 bat_psy_desc.name = pdata->batt_name;
244
245 bat_psy_desc.properties = prop;
246 bat_psy_desc.num_properties = props;
247
248 bat_psy = power_supply_register(&dev->dev, &bat_psy_desc, NULL);
249 if (!IS_ERR(bat_psy)) {
250 schedule_work(&bat_work);
251 } else {
252 ret = PTR_ERR(bat_psy);
253 goto err4;
254 }
255
256 return 0;
257 err4:
258 kfree(prop);
259 err3:
260 if (gpio_is_valid(pdata->charge_gpio))
261 free_irq(gpio_to_irq(pdata->charge_gpio), dev);
262 err2:
263 if (gpio_is_valid(pdata->charge_gpio))
264 gpio_free(pdata->charge_gpio);
265 err:
266 return ret;
267 }
268
wm97xx_bat_remove(struct platform_device * dev)269 static int wm97xx_bat_remove(struct platform_device *dev)
270 {
271 struct wm97xx_pdata *wmdata = dev->dev.platform_data;
272 struct wm97xx_batt_pdata *pdata = wmdata->batt_pdata;
273
274 if (pdata && gpio_is_valid(pdata->charge_gpio)) {
275 free_irq(gpio_to_irq(pdata->charge_gpio), dev);
276 gpio_free(pdata->charge_gpio);
277 }
278 cancel_work_sync(&bat_work);
279 power_supply_unregister(bat_psy);
280 kfree(prop);
281 return 0;
282 }
283
284 static struct platform_driver wm97xx_bat_driver = {
285 .driver = {
286 .name = "wm97xx-battery",
287 #ifdef CONFIG_PM
288 .pm = &wm97xx_bat_pm_ops,
289 #endif
290 },
291 .probe = wm97xx_bat_probe,
292 .remove = wm97xx_bat_remove,
293 };
294
295 module_platform_driver(wm97xx_bat_driver);
296
297 MODULE_LICENSE("GPL");
298 MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
299 MODULE_DESCRIPTION("WM97xx battery driver");
300