1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Battery measurement code for WM97xx
4 *
5 * based on tosa_battery.c
6 *
7 * Copyright (C) 2008 Marek Vasut <marek.vasut@gmail.com>
8 */
9
10 #include <linux/init.h>
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/platform_device.h>
14 #include <linux/power_supply.h>
15 #include <linux/wm97xx.h>
16 #include <linux/spinlock.h>
17 #include <linux/interrupt.h>
18 #include <linux/gpio.h>
19 #include <linux/irq.h>
20 #include <linux/slab.h>
21
22 static struct work_struct bat_work;
23 static DEFINE_MUTEX(work_lock);
24 static int bat_status = POWER_SUPPLY_STATUS_UNKNOWN;
25 static enum power_supply_property *prop;
26
wm97xx_read_bat(struct power_supply * bat_ps)27 static unsigned long wm97xx_read_bat(struct power_supply *bat_ps)
28 {
29 struct wm97xx_batt_pdata *pdata = power_supply_get_drvdata(bat_ps);
30
31 return wm97xx_read_aux_adc(dev_get_drvdata(bat_ps->dev.parent),
32 pdata->batt_aux) * pdata->batt_mult /
33 pdata->batt_div;
34 }
35
wm97xx_read_temp(struct power_supply * bat_ps)36 static unsigned long wm97xx_read_temp(struct power_supply *bat_ps)
37 {
38 struct wm97xx_batt_pdata *pdata = power_supply_get_drvdata(bat_ps);
39
40 return wm97xx_read_aux_adc(dev_get_drvdata(bat_ps->dev.parent),
41 pdata->temp_aux) * pdata->temp_mult /
42 pdata->temp_div;
43 }
44
wm97xx_bat_get_property(struct power_supply * bat_ps,enum power_supply_property psp,union power_supply_propval * val)45 static int wm97xx_bat_get_property(struct power_supply *bat_ps,
46 enum power_supply_property psp,
47 union power_supply_propval *val)
48 {
49 struct wm97xx_batt_pdata *pdata = power_supply_get_drvdata(bat_ps);
50
51 switch (psp) {
52 case POWER_SUPPLY_PROP_STATUS:
53 val->intval = bat_status;
54 break;
55 case POWER_SUPPLY_PROP_TECHNOLOGY:
56 val->intval = pdata->batt_tech;
57 break;
58 case POWER_SUPPLY_PROP_VOLTAGE_NOW:
59 if (pdata->batt_aux >= 0)
60 val->intval = wm97xx_read_bat(bat_ps);
61 else
62 return -EINVAL;
63 break;
64 case POWER_SUPPLY_PROP_TEMP:
65 if (pdata->temp_aux >= 0)
66 val->intval = wm97xx_read_temp(bat_ps);
67 else
68 return -EINVAL;
69 break;
70 case POWER_SUPPLY_PROP_VOLTAGE_MAX:
71 if (pdata->max_voltage >= 0)
72 val->intval = pdata->max_voltage;
73 else
74 return -EINVAL;
75 break;
76 case POWER_SUPPLY_PROP_VOLTAGE_MIN:
77 if (pdata->min_voltage >= 0)
78 val->intval = pdata->min_voltage;
79 else
80 return -EINVAL;
81 break;
82 case POWER_SUPPLY_PROP_PRESENT:
83 val->intval = 1;
84 break;
85 default:
86 return -EINVAL;
87 }
88 return 0;
89 }
90
wm97xx_bat_external_power_changed(struct power_supply * bat_ps)91 static void wm97xx_bat_external_power_changed(struct power_supply *bat_ps)
92 {
93 schedule_work(&bat_work);
94 }
95
wm97xx_bat_update(struct power_supply * bat_ps)96 static void wm97xx_bat_update(struct power_supply *bat_ps)
97 {
98 int old_status = bat_status;
99 struct wm97xx_batt_pdata *pdata = power_supply_get_drvdata(bat_ps);
100
101 mutex_lock(&work_lock);
102
103 bat_status = (pdata->charge_gpio >= 0) ?
104 (gpio_get_value(pdata->charge_gpio) ?
105 POWER_SUPPLY_STATUS_DISCHARGING :
106 POWER_SUPPLY_STATUS_CHARGING) :
107 POWER_SUPPLY_STATUS_UNKNOWN;
108
109 if (old_status != bat_status) {
110 pr_debug("%s: %i -> %i\n", bat_ps->desc->name, old_status,
111 bat_status);
112 power_supply_changed(bat_ps);
113 }
114
115 mutex_unlock(&work_lock);
116 }
117
118 static struct power_supply *bat_psy;
119 static struct power_supply_desc bat_psy_desc = {
120 .type = POWER_SUPPLY_TYPE_BATTERY,
121 .get_property = wm97xx_bat_get_property,
122 .external_power_changed = wm97xx_bat_external_power_changed,
123 .use_for_apm = 1,
124 };
125
wm97xx_bat_work(struct work_struct * work)126 static void wm97xx_bat_work(struct work_struct *work)
127 {
128 wm97xx_bat_update(bat_psy);
129 }
130
wm97xx_chrg_irq(int irq,void * data)131 static irqreturn_t wm97xx_chrg_irq(int irq, void *data)
132 {
133 schedule_work(&bat_work);
134 return IRQ_HANDLED;
135 }
136
137 #ifdef CONFIG_PM
wm97xx_bat_suspend(struct device * dev)138 static int wm97xx_bat_suspend(struct device *dev)
139 {
140 flush_work(&bat_work);
141 return 0;
142 }
143
wm97xx_bat_resume(struct device * dev)144 static int wm97xx_bat_resume(struct device *dev)
145 {
146 schedule_work(&bat_work);
147 return 0;
148 }
149
150 static const struct dev_pm_ops wm97xx_bat_pm_ops = {
151 .suspend = wm97xx_bat_suspend,
152 .resume = wm97xx_bat_resume,
153 };
154 #endif
155
wm97xx_bat_probe(struct platform_device * dev)156 static int wm97xx_bat_probe(struct platform_device *dev)
157 {
158 int ret = 0;
159 int props = 1; /* POWER_SUPPLY_PROP_PRESENT */
160 int i = 0;
161 struct wm97xx_batt_pdata *pdata = dev->dev.platform_data;
162 struct power_supply_config cfg = {};
163
164 if (!pdata) {
165 dev_err(&dev->dev, "No platform data supplied\n");
166 return -EINVAL;
167 }
168
169 cfg.drv_data = pdata;
170
171 if (dev->id != -1)
172 return -EINVAL;
173
174 if (gpio_is_valid(pdata->charge_gpio)) {
175 ret = gpio_request(pdata->charge_gpio, "BATT CHRG");
176 if (ret)
177 goto err;
178 ret = gpio_direction_input(pdata->charge_gpio);
179 if (ret)
180 goto err2;
181 ret = request_irq(gpio_to_irq(pdata->charge_gpio),
182 wm97xx_chrg_irq, 0,
183 "AC Detect", dev);
184 if (ret)
185 goto err2;
186 props++; /* POWER_SUPPLY_PROP_STATUS */
187 }
188
189 if (pdata->batt_tech >= 0)
190 props++; /* POWER_SUPPLY_PROP_TECHNOLOGY */
191 if (pdata->temp_aux >= 0)
192 props++; /* POWER_SUPPLY_PROP_TEMP */
193 if (pdata->batt_aux >= 0)
194 props++; /* POWER_SUPPLY_PROP_VOLTAGE_NOW */
195 if (pdata->max_voltage >= 0)
196 props++; /* POWER_SUPPLY_PROP_VOLTAGE_MAX */
197 if (pdata->min_voltage >= 0)
198 props++; /* POWER_SUPPLY_PROP_VOLTAGE_MIN */
199
200 prop = kcalloc(props, sizeof(*prop), GFP_KERNEL);
201 if (!prop) {
202 ret = -ENOMEM;
203 goto err3;
204 }
205
206 prop[i++] = POWER_SUPPLY_PROP_PRESENT;
207 if (pdata->charge_gpio >= 0)
208 prop[i++] = POWER_SUPPLY_PROP_STATUS;
209 if (pdata->batt_tech >= 0)
210 prop[i++] = POWER_SUPPLY_PROP_TECHNOLOGY;
211 if (pdata->temp_aux >= 0)
212 prop[i++] = POWER_SUPPLY_PROP_TEMP;
213 if (pdata->batt_aux >= 0)
214 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_NOW;
215 if (pdata->max_voltage >= 0)
216 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MAX;
217 if (pdata->min_voltage >= 0)
218 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MIN;
219
220 INIT_WORK(&bat_work, wm97xx_bat_work);
221
222 if (!pdata->batt_name) {
223 dev_info(&dev->dev, "Please consider setting proper battery "
224 "name in platform definition file, falling "
225 "back to name \"wm97xx-batt\"\n");
226 bat_psy_desc.name = "wm97xx-batt";
227 } else
228 bat_psy_desc.name = pdata->batt_name;
229
230 bat_psy_desc.properties = prop;
231 bat_psy_desc.num_properties = props;
232
233 bat_psy = power_supply_register(&dev->dev, &bat_psy_desc, &cfg);
234 if (!IS_ERR(bat_psy)) {
235 schedule_work(&bat_work);
236 } else {
237 ret = PTR_ERR(bat_psy);
238 goto err4;
239 }
240
241 return 0;
242 err4:
243 kfree(prop);
244 err3:
245 if (gpio_is_valid(pdata->charge_gpio))
246 free_irq(gpio_to_irq(pdata->charge_gpio), dev);
247 err2:
248 if (gpio_is_valid(pdata->charge_gpio))
249 gpio_free(pdata->charge_gpio);
250 err:
251 return ret;
252 }
253
wm97xx_bat_remove(struct platform_device * dev)254 static int wm97xx_bat_remove(struct platform_device *dev)
255 {
256 struct wm97xx_batt_pdata *pdata = dev->dev.platform_data;
257
258 if (pdata && gpio_is_valid(pdata->charge_gpio)) {
259 free_irq(gpio_to_irq(pdata->charge_gpio), dev);
260 gpio_free(pdata->charge_gpio);
261 }
262 cancel_work_sync(&bat_work);
263 power_supply_unregister(bat_psy);
264 kfree(prop);
265 return 0;
266 }
267
268 static struct platform_driver wm97xx_bat_driver = {
269 .driver = {
270 .name = "wm97xx-battery",
271 #ifdef CONFIG_PM
272 .pm = &wm97xx_bat_pm_ops,
273 #endif
274 },
275 .probe = wm97xx_bat_probe,
276 .remove = wm97xx_bat_remove,
277 };
278
279 module_platform_driver(wm97xx_bat_driver);
280
281 MODULE_LICENSE("GPL");
282 MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
283 MODULE_DESCRIPTION("WM97xx battery driver");
284
