tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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_cansleep(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 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 = devm_kzalloc(&pdev->dev, sizeof(*gpio_charger),
90 GFP_KERNEL);
91 if (!gpio_charger) {
92 dev_err(&pdev->dev, "Failed to alloc driver structure\n");
93 return -ENOMEM;
94 }
95
96 charger = &gpio_charger->charger;
97
98 charger->name = pdata->name ? pdata->name : "gpio-charger";
99 charger->type = pdata->type;
100 charger->properties = gpio_charger_properties;
101 charger->num_properties = ARRAY_SIZE(gpio_charger_properties);
102 charger->get_property = gpio_charger_get_property;
103 charger->supplied_to = pdata->supplied_to;
104 charger->num_supplicants = pdata->num_supplicants;
105
106 ret = gpio_request(pdata->gpio, dev_name(&pdev->dev));
107 if (ret) {
108 dev_err(&pdev->dev, "Failed to request gpio pin: %d\n", ret);
109 goto err_free;
110 }
111 ret = gpio_direction_input(pdata->gpio);
112 if (ret) {
113 dev_err(&pdev->dev, "Failed to set gpio to input: %d\n", ret);
114 goto err_gpio_free;
115 }
116
117 gpio_charger->pdata = pdata;
118
119 ret = power_supply_register(&pdev->dev, charger);
120 if (ret < 0) {
121 dev_err(&pdev->dev, "Failed to register power supply: %d\n",
122 ret);
123 goto err_gpio_free;
124 }
125
126 irq = gpio_to_irq(pdata->gpio);
127 if (irq > 0) {
128 ret = request_any_context_irq(irq, gpio_charger_irq,
129 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
130 dev_name(&pdev->dev), charger);
131 if (ret < 0)
132 dev_warn(&pdev->dev, "Failed to request irq: %d\n", ret);
133 else
134 gpio_charger->irq = irq;
135 }
136
137 platform_set_drvdata(pdev, gpio_charger);
138
139 return 0;
140
141err_gpio_free:
142 gpio_free(pdata->gpio);
143err_free:
144 return ret;
145}
146
147static int 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 return 0;
159}
160
161#ifdef CONFIG_PM_SLEEP
162static int gpio_charger_resume(struct device *dev)
163{
164 struct platform_device *pdev = to_platform_device(dev);
165 struct gpio_charger *gpio_charger = platform_get_drvdata(pdev);
166
167 power_supply_changed(&gpio_charger->charger);
168
169 return 0;
170}
171#endif
172
173static SIMPLE_DEV_PM_OPS(gpio_charger_pm_ops, NULL, gpio_charger_resume);
174
175static struct platform_driver gpio_charger_driver = {
176 .probe = gpio_charger_probe,
177 .remove = gpio_charger_remove,
178 .driver = {
179 .name = "gpio-charger",
180 .owner = THIS_MODULE,
181 .pm = &gpio_charger_pm_ops,
182 },
183};
184
185module_platform_driver(gpio_charger_driver);
186
187MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
188MODULE_DESCRIPTION("Driver for chargers which report their online status through a GPIO");
189MODULE_LICENSE("GPL");
190MODULE_ALIAS("platform:gpio-charger");