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->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_ps = {
129 .type = POWER_SUPPLY_TYPE_BATTERY,
130 .get_property = wm97xx_bat_get_property,
131 .external_power_changed = wm97xx_bat_external_power_changed,
132 .use_for_apm = 1,
133 };
134
wm97xx_bat_work(struct work_struct * work)135 static void wm97xx_bat_work(struct work_struct *work)
136 {
137 wm97xx_bat_update(&bat_ps);
138 }
139
wm97xx_chrg_irq(int irq,void * data)140 static irqreturn_t wm97xx_chrg_irq(int irq, void *data)
141 {
142 schedule_work(&bat_work);
143 return IRQ_HANDLED;
144 }
145
146 #ifdef CONFIG_PM
wm97xx_bat_suspend(struct device * dev)147 static int wm97xx_bat_suspend(struct device *dev)
148 {
149 flush_work(&bat_work);
150 return 0;
151 }
152
wm97xx_bat_resume(struct device * dev)153 static int wm97xx_bat_resume(struct device *dev)
154 {
155 schedule_work(&bat_work);
156 return 0;
157 }
158
159 static const struct dev_pm_ops wm97xx_bat_pm_ops = {
160 .suspend = wm97xx_bat_suspend,
161 .resume = wm97xx_bat_resume,
162 };
163 #endif
164
wm97xx_bat_probe(struct platform_device * dev)165 static int wm97xx_bat_probe(struct platform_device *dev)
166 {
167 int ret = 0;
168 int props = 1; /* POWER_SUPPLY_PROP_PRESENT */
169 int i = 0;
170 struct wm97xx_pdata *wmdata = dev->dev.platform_data;
171 struct wm97xx_batt_pdata *pdata;
172
173 if (!wmdata) {
174 dev_err(&dev->dev, "No platform data supplied\n");
175 return -EINVAL;
176 }
177
178 pdata = wmdata->batt_pdata;
179
180 if (dev->id != -1)
181 return -EINVAL;
182
183 if (!pdata) {
184 dev_err(&dev->dev, "No platform_data supplied\n");
185 return -EINVAL;
186 }
187
188 if (gpio_is_valid(pdata->charge_gpio)) {
189 ret = gpio_request(pdata->charge_gpio, "BATT CHRG");
190 if (ret)
191 goto err;
192 ret = gpio_direction_input(pdata->charge_gpio);
193 if (ret)
194 goto err2;
195 ret = request_irq(gpio_to_irq(pdata->charge_gpio),
196 wm97xx_chrg_irq, 0,
197 "AC Detect", dev);
198 if (ret)
199 goto err2;
200 props++; /* POWER_SUPPLY_PROP_STATUS */
201 }
202
203 if (pdata->batt_tech >= 0)
204 props++; /* POWER_SUPPLY_PROP_TECHNOLOGY */
205 if (pdata->temp_aux >= 0)
206 props++; /* POWER_SUPPLY_PROP_TEMP */
207 if (pdata->batt_aux >= 0)
208 props++; /* POWER_SUPPLY_PROP_VOLTAGE_NOW */
209 if (pdata->max_voltage >= 0)
210 props++; /* POWER_SUPPLY_PROP_VOLTAGE_MAX */
211 if (pdata->min_voltage >= 0)
212 props++; /* POWER_SUPPLY_PROP_VOLTAGE_MIN */
213
214 prop = kzalloc(props * sizeof(*prop), GFP_KERNEL);
215 if (!prop) {
216 ret = -ENOMEM;
217 goto err3;
218 }
219
220 prop[i++] = POWER_SUPPLY_PROP_PRESENT;
221 if (pdata->charge_gpio >= 0)
222 prop[i++] = POWER_SUPPLY_PROP_STATUS;
223 if (pdata->batt_tech >= 0)
224 prop[i++] = POWER_SUPPLY_PROP_TECHNOLOGY;
225 if (pdata->temp_aux >= 0)
226 prop[i++] = POWER_SUPPLY_PROP_TEMP;
227 if (pdata->batt_aux >= 0)
228 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_NOW;
229 if (pdata->max_voltage >= 0)
230 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MAX;
231 if (pdata->min_voltage >= 0)
232 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MIN;
233
234 INIT_WORK(&bat_work, wm97xx_bat_work);
235
236 if (!pdata->batt_name) {
237 dev_info(&dev->dev, "Please consider setting proper battery "
238 "name in platform definition file, falling "
239 "back to name \"wm97xx-batt\"\n");
240 bat_ps.name = "wm97xx-batt";
241 } else
242 bat_ps.name = pdata->batt_name;
243
244 bat_ps.properties = prop;
245 bat_ps.num_properties = props;
246
247 ret = power_supply_register(&dev->dev, &bat_ps);
248 if (!ret)
249 schedule_work(&bat_work);
250 else
251 goto err4;
252
253 return 0;
254 err4:
255 kfree(prop);
256 err3:
257 if (gpio_is_valid(pdata->charge_gpio))
258 free_irq(gpio_to_irq(pdata->charge_gpio), dev);
259 err2:
260 if (gpio_is_valid(pdata->charge_gpio))
261 gpio_free(pdata->charge_gpio);
262 err:
263 return ret;
264 }
265
wm97xx_bat_remove(struct platform_device * dev)266 static int wm97xx_bat_remove(struct platform_device *dev)
267 {
268 struct wm97xx_pdata *wmdata = dev->dev.platform_data;
269 struct wm97xx_batt_pdata *pdata = wmdata->batt_pdata;
270
271 if (pdata && gpio_is_valid(pdata->charge_gpio)) {
272 free_irq(gpio_to_irq(pdata->charge_gpio), dev);
273 gpio_free(pdata->charge_gpio);
274 }
275 cancel_work_sync(&bat_work);
276 power_supply_unregister(&bat_ps);
277 kfree(prop);
278 return 0;
279 }
280
281 static struct platform_driver wm97xx_bat_driver = {
282 .driver = {
283 .name = "wm97xx-battery",
284 .owner = THIS_MODULE,
285 #ifdef CONFIG_PM
286 .pm = &wm97xx_bat_pm_ops,
287 #endif
288 },
289 .probe = wm97xx_bat_probe,
290 .remove = wm97xx_bat_remove,
291 };
292
293 module_platform_driver(wm97xx_bat_driver);
294
295 MODULE_LICENSE("GPL");
296 MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
297 MODULE_DESCRIPTION("WM97xx battery driver");
298