1/*
  2 *  Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
  3 *  Driver for chargers which report their online status through a GPIO pin
  4 *
  5 *  This program is free software; you can redistribute it and/or modify it
  6 *  under  the terms of the GNU General  Public License as published by the
  7 *  Free Software Foundation;  either version 2 of the License, or (at your
  8 *  option) any later version.
  9 *
 10 *  You should have received a copy of the GNU General Public License along
 11 *  with this program; if not, write to the Free Software Foundation, Inc.,
 12 *  675 Mass Ave, Cambridge, MA 02139, USA.
 13 *
 14 */
 15
 16#include <linux/device.h>
 17#include <linux/gpio.h>
 18#include <linux/init.h>
 19#include <linux/interrupt.h>
 20#include <linux/kernel.h>
 21#include <linux/module.h>
 22#include <linux/platform_device.h>
 23#include <linux/power_supply.h>
 24#include <linux/slab.h>
 25
 26#include <linux/power/gpio-charger.h>
 27
 28struct gpio_charger {
 29	const struct gpio_charger_platform_data *pdata;
 30	unsigned int irq;
 31
 32	struct power_supply charger;
 33};
 34
 35static irqreturn_t gpio_charger_irq(int irq, void *devid)
 36{
 37	struct power_supply *charger = devid;
 38
 39	power_supply_changed(charger);
 40
 41	return IRQ_HANDLED;
 42}
 43
 44static inline struct gpio_charger *psy_to_gpio_charger(struct power_supply *psy)
 45{
 46	return container_of(psy, struct gpio_charger, charger);
 47}
 48
 49static int gpio_charger_get_property(struct power_supply *psy,
 50		enum power_supply_property psp, union power_supply_propval *val)
 51{
 52	struct gpio_charger *gpio_charger = psy_to_gpio_charger(psy);
 53	const struct gpio_charger_platform_data *pdata = gpio_charger->pdata;
 54
 55	switch (psp) {
 56	case POWER_SUPPLY_PROP_ONLINE:
 57		val->intval = gpio_get_value(pdata->gpio);
 58		val->intval ^= pdata->gpio_active_low;
 59		break;
 60	default:
 61		return -EINVAL;
 62	}
 63
 64	return 0;
 65}
 66
 67static enum power_supply_property gpio_charger_properties[] = {
 68	POWER_SUPPLY_PROP_ONLINE,
 69};
 70
 71static int __devinit gpio_charger_probe(struct platform_device *pdev)
 72{
 73	const struct gpio_charger_platform_data *pdata = pdev->dev.platform_data;
 74	struct gpio_charger *gpio_charger;
 75	struct power_supply *charger;
 76	int ret;
 77	int irq;
 78
 79	if (!pdata) {
 80		dev_err(&pdev->dev, "No platform data\n");
 81		return -EINVAL;
 82	}
 83
 84	if (!gpio_is_valid(pdata->gpio)) {
 85		dev_err(&pdev->dev, "Invalid gpio pin\n");
 86		return -EINVAL;
 87	}
 88
 89	gpio_charger = kzalloc(sizeof(*gpio_charger), GFP_KERNEL);
 90	if (!gpio_charger) {
 91		dev_err(&pdev->dev, "Failed to alloc driver structure\n");
 92		return -ENOMEM;
 93	}
 94
 95	charger = &gpio_charger->charger;
 96
 97	charger->name = pdata->name ? pdata->name : "gpio-charger";
 98	charger->type = pdata->type;
 99	charger->properties = gpio_charger_properties;
100	charger->num_properties = ARRAY_SIZE(gpio_charger_properties);
101	charger->get_property = gpio_charger_get_property;
102	charger->supplied_to = pdata->supplied_to;
103	charger->num_supplicants = pdata->num_supplicants;
104
105	ret = gpio_request(pdata->gpio, dev_name(&pdev->dev));
106	if (ret) {
107		dev_err(&pdev->dev, "Failed to request gpio pin: %d\n", ret);
108		goto err_free;
109	}
110	ret = gpio_direction_input(pdata->gpio);
111	if (ret) {
112		dev_err(&pdev->dev, "Failed to set gpio to input: %d\n", ret);
113		goto err_gpio_free;
114	}
115
116	gpio_charger->pdata = pdata;
117
118	ret = power_supply_register(&pdev->dev, charger);
119	if (ret < 0) {
120		dev_err(&pdev->dev, "Failed to register power supply: %d\n",
121			ret);
122		goto err_gpio_free;
123	}
124
125	irq = gpio_to_irq(pdata->gpio);
126	if (irq > 0) {
127		ret = request_any_context_irq(irq, gpio_charger_irq,
128				IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
129				dev_name(&pdev->dev), charger);
130		if (ret < 0)
131			dev_warn(&pdev->dev, "Failed to request irq: %d\n", ret);
132		else
133			gpio_charger->irq = irq;
134	}
135
136	platform_set_drvdata(pdev, gpio_charger);
137
138	return 0;
139
140err_gpio_free:
141	gpio_free(pdata->gpio);
142err_free:
143	kfree(gpio_charger);
144	return ret;
145}
146
147static int __devexit gpio_charger_remove(struct platform_device *pdev)
148{
149	struct gpio_charger *gpio_charger = platform_get_drvdata(pdev);
150
151	if (gpio_charger->irq)
152		free_irq(gpio_charger->irq, &gpio_charger->charger);
153
154	power_supply_unregister(&gpio_charger->charger);
155
156	gpio_free(gpio_charger->pdata->gpio);
157
158	platform_set_drvdata(pdev, NULL);
159	kfree(gpio_charger);
160
161	return 0;
162}
163
164#ifdef CONFIG_PM_SLEEP
165static int gpio_charger_resume(struct device *dev)
166{
167	struct platform_device *pdev = to_platform_device(dev);
168	struct gpio_charger *gpio_charger = platform_get_drvdata(pdev);
169
170	power_supply_changed(&gpio_charger->charger);
171
172	return 0;
173}
174#endif
175
176static SIMPLE_DEV_PM_OPS(gpio_charger_pm_ops, NULL, gpio_charger_resume);
177
178static struct platform_driver gpio_charger_driver = {
179	.probe = gpio_charger_probe,
180	.remove = __devexit_p(gpio_charger_remove),
181	.driver = {
182		.name = "gpio-charger",
183		.owner = THIS_MODULE,
184		.pm = &gpio_charger_pm_ops,
185	},
186};
187
188module_platform_driver(gpio_charger_driver);
189
190MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
191MODULE_DESCRIPTION("Driver for chargers which report their online status through a GPIO");
192MODULE_LICENSE("GPL");
193MODULE_ALIAS("platform:gpio-charger");