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 
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 
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 
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 
95 static void wm97xx_bat_external_power_changed(struct power_supply *bat_ps)
96 {
97 	schedule_work(&bat_work);
98 }
99 
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 
130 static void wm97xx_bat_work(struct work_struct *work)
131 {
132 	wm97xx_bat_update(bat_psy);
133 }
134 
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
142 static int wm97xx_bat_suspend(struct device *dev)
143 {
144 	flush_work(&bat_work);
145 	return 0;
146 }
147 
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 
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 
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