1 /*
2 * Battery measurement code for WM97xx
3 *
4 * based on tosa_battery.c
5 *
6 * Copyright (C) 2008 Marek Vasut <marek.vasut@gmail.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 *
12 */
13
14 #include <linux/init.h>
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/platform_device.h>
18 #include <linux/power_supply.h>
19 #include <linux/wm97xx.h>
20 #include <linux/spinlock.h>
21 #include <linux/interrupt.h>
22 #include <linux/gpio.h>
23 #include <linux/irq.h>
24 #include <linux/slab.h>
25
26 static struct work_struct bat_work;
27 static DEFINE_MUTEX(work_lock);
28 static int bat_status = POWER_SUPPLY_STATUS_UNKNOWN;
29 static enum power_supply_property *prop;
30
wm97xx_read_bat(struct power_supply * bat_ps)31 static unsigned long wm97xx_read_bat(struct power_supply *bat_ps)
32 {
33 struct wm97xx_batt_pdata *pdata = power_supply_get_drvdata(bat_ps);
34
35 return wm97xx_read_aux_adc(dev_get_drvdata(bat_ps->dev.parent),
36 pdata->batt_aux) * pdata->batt_mult /
37 pdata->batt_div;
38 }
39
wm97xx_read_temp(struct power_supply * bat_ps)40 static unsigned long wm97xx_read_temp(struct power_supply *bat_ps)
41 {
42 struct wm97xx_batt_pdata *pdata = power_supply_get_drvdata(bat_ps);
43
44 return wm97xx_read_aux_adc(dev_get_drvdata(bat_ps->dev.parent),
45 pdata->temp_aux) * pdata->temp_mult /
46 pdata->temp_div;
47 }
48
wm97xx_bat_get_property(struct power_supply * bat_ps,enum power_supply_property psp,union power_supply_propval * val)49 static int wm97xx_bat_get_property(struct power_supply *bat_ps,
50 enum power_supply_property psp,
51 union power_supply_propval *val)
52 {
53 struct wm97xx_batt_pdata *pdata = power_supply_get_drvdata(bat_ps);
54
55 switch (psp) {
56 case POWER_SUPPLY_PROP_STATUS:
57 val->intval = bat_status;
58 break;
59 case POWER_SUPPLY_PROP_TECHNOLOGY:
60 val->intval = pdata->batt_tech;
61 break;
62 case POWER_SUPPLY_PROP_VOLTAGE_NOW:
63 if (pdata->batt_aux >= 0)
64 val->intval = wm97xx_read_bat(bat_ps);
65 else
66 return -EINVAL;
67 break;
68 case POWER_SUPPLY_PROP_TEMP:
69 if (pdata->temp_aux >= 0)
70 val->intval = wm97xx_read_temp(bat_ps);
71 else
72 return -EINVAL;
73 break;
74 case POWER_SUPPLY_PROP_VOLTAGE_MAX:
75 if (pdata->max_voltage >= 0)
76 val->intval = pdata->max_voltage;
77 else
78 return -EINVAL;
79 break;
80 case POWER_SUPPLY_PROP_VOLTAGE_MIN:
81 if (pdata->min_voltage >= 0)
82 val->intval = pdata->min_voltage;
83 else
84 return -EINVAL;
85 break;
86 case POWER_SUPPLY_PROP_PRESENT:
87 val->intval = 1;
88 break;
89 default:
90 return -EINVAL;
91 }
92 return 0;
93 }
94
wm97xx_bat_external_power_changed(struct power_supply * bat_ps)95 static void wm97xx_bat_external_power_changed(struct power_supply *bat_ps)
96 {
97 schedule_work(&bat_work);
98 }
99
wm97xx_bat_update(struct power_supply * bat_ps)100 static void wm97xx_bat_update(struct power_supply *bat_ps)
101 {
102 int old_status = bat_status;
103 struct wm97xx_batt_pdata *pdata = power_supply_get_drvdata(bat_ps);
104
105 mutex_lock(&work_lock);
106
107 bat_status = (pdata->charge_gpio >= 0) ?
108 (gpio_get_value(pdata->charge_gpio) ?
109 POWER_SUPPLY_STATUS_DISCHARGING :
110 POWER_SUPPLY_STATUS_CHARGING) :
111 POWER_SUPPLY_STATUS_UNKNOWN;
112
113 if (old_status != bat_status) {
114 pr_debug("%s: %i -> %i\n", bat_ps->desc->name, old_status,
115 bat_status);
116 power_supply_changed(bat_ps);
117 }
118
119 mutex_unlock(&work_lock);
120 }
121
122 static struct power_supply *bat_psy;
123 static struct power_supply_desc bat_psy_desc = {
124 .type = POWER_SUPPLY_TYPE_BATTERY,
125 .get_property = wm97xx_bat_get_property,
126 .external_power_changed = wm97xx_bat_external_power_changed,
127 .use_for_apm = 1,
128 };
129
wm97xx_bat_work(struct work_struct * work)130 static void wm97xx_bat_work(struct work_struct *work)
131 {
132 wm97xx_bat_update(bat_psy);
133 }
134
wm97xx_chrg_irq(int irq,void * data)135 static irqreturn_t wm97xx_chrg_irq(int irq, void *data)
136 {
137 schedule_work(&bat_work);
138 return IRQ_HANDLED;
139 }
140
141 #ifdef CONFIG_PM
wm97xx_bat_suspend(struct device * dev)142 static int wm97xx_bat_suspend(struct device *dev)
143 {
144 flush_work(&bat_work);
145 return 0;
146 }
147
wm97xx_bat_resume(struct device * dev)148 static int wm97xx_bat_resume(struct device *dev)
149 {
150 schedule_work(&bat_work);
151 return 0;
152 }
153
154 static const struct dev_pm_ops wm97xx_bat_pm_ops = {
155 .suspend = wm97xx_bat_suspend,
156 .resume = wm97xx_bat_resume,
157 };
158 #endif
159
wm97xx_bat_probe(struct platform_device * dev)160 static int wm97xx_bat_probe(struct platform_device *dev)
161 {
162 int ret = 0;
163 int props = 1; /* POWER_SUPPLY_PROP_PRESENT */
164 int i = 0;
165 struct wm97xx_batt_pdata *pdata = dev->dev.platform_data;
166 struct power_supply_config cfg = {};
167
168 if (!pdata) {
169 dev_err(&dev->dev, "No platform data supplied\n");
170 return -EINVAL;
171 }
172
173 cfg.drv_data = pdata;
174
175 if (dev->id != -1)
176 return -EINVAL;
177
178 if (gpio_is_valid(pdata->charge_gpio)) {
179 ret = gpio_request(pdata->charge_gpio, "BATT CHRG");
180 if (ret)
181 goto err;
182 ret = gpio_direction_input(pdata->charge_gpio);
183 if (ret)
184 goto err2;
185 ret = request_irq(gpio_to_irq(pdata->charge_gpio),
186 wm97xx_chrg_irq, 0,
187 "AC Detect", dev);
188 if (ret)
189 goto err2;
190 props++; /* POWER_SUPPLY_PROP_STATUS */
191 }
192
193 if (pdata->batt_tech >= 0)
194 props++; /* POWER_SUPPLY_PROP_TECHNOLOGY */
195 if (pdata->temp_aux >= 0)
196 props++; /* POWER_SUPPLY_PROP_TEMP */
197 if (pdata->batt_aux >= 0)
198 props++; /* POWER_SUPPLY_PROP_VOLTAGE_NOW */
199 if (pdata->max_voltage >= 0)
200 props++; /* POWER_SUPPLY_PROP_VOLTAGE_MAX */
201 if (pdata->min_voltage >= 0)
202 props++; /* POWER_SUPPLY_PROP_VOLTAGE_MIN */
203
204 prop = kcalloc(props, sizeof(*prop), GFP_KERNEL);
205 if (!prop) {
206 ret = -ENOMEM;
207 goto err3;
208 }
209
210 prop[i++] = POWER_SUPPLY_PROP_PRESENT;
211 if (pdata->charge_gpio >= 0)
212 prop[i++] = POWER_SUPPLY_PROP_STATUS;
213 if (pdata->batt_tech >= 0)
214 prop[i++] = POWER_SUPPLY_PROP_TECHNOLOGY;
215 if (pdata->temp_aux >= 0)
216 prop[i++] = POWER_SUPPLY_PROP_TEMP;
217 if (pdata->batt_aux >= 0)
218 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_NOW;
219 if (pdata->max_voltage >= 0)
220 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MAX;
221 if (pdata->min_voltage >= 0)
222 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MIN;
223
224 INIT_WORK(&bat_work, wm97xx_bat_work);
225
226 if (!pdata->batt_name) {
227 dev_info(&dev->dev, "Please consider setting proper battery "
228 "name in platform definition file, falling "
229 "back to name \"wm97xx-batt\"\n");
230 bat_psy_desc.name = "wm97xx-batt";
231 } else
232 bat_psy_desc.name = pdata->batt_name;
233
234 bat_psy_desc.properties = prop;
235 bat_psy_desc.num_properties = props;
236
237 bat_psy = power_supply_register(&dev->dev, &bat_psy_desc, &cfg);
238 if (!IS_ERR(bat_psy)) {
239 schedule_work(&bat_work);
240 } else {
241 ret = PTR_ERR(bat_psy);
242 goto err4;
243 }
244
245 return 0;
246 err4:
247 kfree(prop);
248 err3:
249 if (gpio_is_valid(pdata->charge_gpio))
250 free_irq(gpio_to_irq(pdata->charge_gpio), dev);
251 err2:
252 if (gpio_is_valid(pdata->charge_gpio))
253 gpio_free(pdata->charge_gpio);
254 err:
255 return ret;
256 }
257
wm97xx_bat_remove(struct platform_device * dev)258 static int wm97xx_bat_remove(struct platform_device *dev)
259 {
260 struct wm97xx_batt_pdata *pdata = dev->dev.platform_data;
261
262 if (pdata && gpio_is_valid(pdata->charge_gpio)) {
263 free_irq(gpio_to_irq(pdata->charge_gpio), dev);
264 gpio_free(pdata->charge_gpio);
265 }
266 cancel_work_sync(&bat_work);
267 power_supply_unregister(bat_psy);
268 kfree(prop);
269 return 0;
270 }
271
272 static struct platform_driver wm97xx_bat_driver = {
273 .driver = {
274 .name = "wm97xx-battery",
275 #ifdef CONFIG_PM
276 .pm = &wm97xx_bat_pm_ops,
277 #endif
278 },
279 .probe = wm97xx_bat_probe,
280 .remove = wm97xx_bat_remove,
281 };
282
283 module_platform_driver(wm97xx_bat_driver);
284
285 MODULE_LICENSE("GPL");
286 MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
287 MODULE_DESCRIPTION("WM97xx battery driver");
288