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 
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 
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 
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 
91 static void wm97xx_bat_external_power_changed(struct power_supply *bat_ps)
92 {
93 	schedule_work(&bat_work);
94 }
95 
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 
126 static void wm97xx_bat_work(struct work_struct *work)
127 {
128 	wm97xx_bat_update(bat_psy);
129 }
130 
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
138 static int wm97xx_bat_suspend(struct device *dev)
139 {
140 	flush_work(&bat_work);
141 	return 0;
142 }
143 
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 
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 
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