wm97xx_battery.c

  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/consumer.h>
 19#include <linux/irq.h>
 20#include <linux/slab.h>
 21
 22static struct work_struct bat_work;
 23static struct gpio_desc *charge_gpiod;
 24static DEFINE_MUTEX(work_lock);
 25static int bat_status = POWER_SUPPLY_STATUS_UNKNOWN;
 26static enum power_supply_property *prop;
 27
 28static unsigned long wm97xx_read_bat(struct power_supply *bat_ps)
 29{
 30	struct wm97xx_batt_pdata *pdata = power_supply_get_drvdata(bat_ps);
 31
 32	return wm97xx_read_aux_adc(dev_get_drvdata(bat_ps->dev.parent),
 33					pdata->batt_aux) * pdata->batt_mult /
 34					pdata->batt_div;
 35}
 36
 37static unsigned long wm97xx_read_temp(struct power_supply *bat_ps)
 38{
 39	struct wm97xx_batt_pdata *pdata = power_supply_get_drvdata(bat_ps);
 40
 41	return wm97xx_read_aux_adc(dev_get_drvdata(bat_ps->dev.parent),
 42					pdata->temp_aux) * pdata->temp_mult /
 43					pdata->temp_div;
 44}
 45
 46static int wm97xx_bat_get_property(struct power_supply *bat_ps,
 47			    enum power_supply_property psp,
 48			    union power_supply_propval *val)
 49{
 50	struct wm97xx_batt_pdata *pdata = power_supply_get_drvdata(bat_ps);
 51
 52	switch (psp) {
 53	case POWER_SUPPLY_PROP_STATUS:
 54		val->intval = bat_status;
 55		break;
 56	case POWER_SUPPLY_PROP_TECHNOLOGY:
 57		val->intval = pdata->batt_tech;
 58		break;
 59	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
 60		if (pdata->batt_aux >= 0)
 61			val->intval = wm97xx_read_bat(bat_ps);
 62		else
 63			return -EINVAL;
 64		break;
 65	case POWER_SUPPLY_PROP_TEMP:
 66		if (pdata->temp_aux >= 0)
 67			val->intval = wm97xx_read_temp(bat_ps);
 68		else
 69			return -EINVAL;
 70		break;
 71	case POWER_SUPPLY_PROP_VOLTAGE_MAX:
 72		if (pdata->max_voltage >= 0)
 73			val->intval = pdata->max_voltage;
 74		else
 75			return -EINVAL;
 76		break;
 77	case POWER_SUPPLY_PROP_VOLTAGE_MIN:
 78		if (pdata->min_voltage >= 0)
 79			val->intval = pdata->min_voltage;
 80		else
 81			return -EINVAL;
 82		break;
 83	case POWER_SUPPLY_PROP_PRESENT:
 84		val->intval = 1;
 85		break;
 86	default:
 87		return -EINVAL;
 88	}
 89	return 0;
 90}
 91
 92static void wm97xx_bat_external_power_changed(struct power_supply *bat_ps)
 93{
 94	schedule_work(&bat_work);
 95}
 96
 97static void wm97xx_bat_update(struct power_supply *bat_ps)
 98{
 99	int old_status = bat_status;
100
101	mutex_lock(&work_lock);
102
103	bat_status = (charge_gpiod) ?
104			(gpiod_get_value(charge_gpiod) ?
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
118static struct power_supply *bat_psy;
119static 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
126static void wm97xx_bat_work(struct work_struct *work)
127{
128	wm97xx_bat_update(bat_psy);
129}
130
131static 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
138static int wm97xx_bat_suspend(struct device *dev)
139{
140	flush_work(&bat_work);
141	return 0;
142}
143
144static int wm97xx_bat_resume(struct device *dev)
145{
146	schedule_work(&bat_work);
147	return 0;
148}
149
150static const struct dev_pm_ops wm97xx_bat_pm_ops = {
151	.suspend	= wm97xx_bat_suspend,
152	.resume		= wm97xx_bat_resume,
153};
154#endif
155
156static 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	charge_gpiod = devm_gpiod_get_optional(&dev->dev, NULL, GPIOD_IN);
175	if (IS_ERR(charge_gpiod))
176		return dev_err_probe(&dev->dev,
177				     PTR_ERR(charge_gpiod),
178				     "failed to get charge GPIO\n");
179	if (charge_gpiod) {
180		gpiod_set_consumer_name(charge_gpiod, "BATT CHRG");
181		props++;	/* POWER_SUPPLY_PROP_STATUS */
182	}
183
184	if (pdata->batt_tech >= 0)
185		props++;	/* POWER_SUPPLY_PROP_TECHNOLOGY */
186	if (pdata->temp_aux >= 0)
187		props++;	/* POWER_SUPPLY_PROP_TEMP */
188	if (pdata->batt_aux >= 0)
189		props++;	/* POWER_SUPPLY_PROP_VOLTAGE_NOW */
190	if (pdata->max_voltage >= 0)
191		props++;	/* POWER_SUPPLY_PROP_VOLTAGE_MAX */
192	if (pdata->min_voltage >= 0)
193		props++;	/* POWER_SUPPLY_PROP_VOLTAGE_MIN */
194
195	prop = kcalloc(props, sizeof(*prop), GFP_KERNEL);
196	if (!prop)
197		return -ENOMEM;
198
199	prop[i++] = POWER_SUPPLY_PROP_PRESENT;
200	if (charge_gpiod)
201		prop[i++] = POWER_SUPPLY_PROP_STATUS;
202	if (pdata->batt_tech >= 0)
203		prop[i++] = POWER_SUPPLY_PROP_TECHNOLOGY;
204	if (pdata->temp_aux >= 0)
205		prop[i++] = POWER_SUPPLY_PROP_TEMP;
206	if (pdata->batt_aux >= 0)
207		prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_NOW;
208	if (pdata->max_voltage >= 0)
209		prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MAX;
210	if (pdata->min_voltage >= 0)
211		prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MIN;
212
213	INIT_WORK(&bat_work, wm97xx_bat_work);
214
215	if (!pdata->batt_name) {
216		dev_info(&dev->dev, "Please consider setting proper battery "
217				"name in platform definition file, falling "
218				"back to name \"wm97xx-batt\"\n");
219		bat_psy_desc.name = "wm97xx-batt";
220	} else
221		bat_psy_desc.name = pdata->batt_name;
222
223	bat_psy_desc.properties = prop;
224	bat_psy_desc.num_properties = props;
225
226	bat_psy = power_supply_register(&dev->dev, &bat_psy_desc, &cfg);
227	if (!IS_ERR(bat_psy)) {
228		schedule_work(&bat_work);
229	} else {
230		ret = PTR_ERR(bat_psy);
231		goto free;
232	}
233
234	if (charge_gpiod) {
235		ret = request_irq(gpiod_to_irq(charge_gpiod), wm97xx_chrg_irq,
236				  0, "AC Detect", dev);
237		if (ret) {
238			dev_err_probe(&dev->dev, ret,
239				      "failed to request GPIO irq\n");
240			goto unregister;
241		}
242	}
243
244	return 0;
245
246unregister:
247	power_supply_unregister(bat_psy);
248
249free:
250	kfree(prop);
251
252	return ret;
253}
254
255static void wm97xx_bat_remove(struct platform_device *dev)
256{
257	if (charge_gpiod)
258		free_irq(gpiod_to_irq(charge_gpiod), dev);
259	cancel_work_sync(&bat_work);
260	power_supply_unregister(bat_psy);
261	kfree(prop);
262}
263
264static struct platform_driver wm97xx_bat_driver = {
265	.driver	= {
266		.name	= "wm97xx-battery",
267#ifdef CONFIG_PM
268		.pm	= &wm97xx_bat_pm_ops,
269#endif
270	},
271	.probe		= wm97xx_bat_probe,
272	.remove		= wm97xx_bat_remove,
273};
274
275module_platform_driver(wm97xx_bat_driver);
276
277MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
278MODULE_DESCRIPTION("WM97xx battery driver");