2 * drivers/extcon/extcon_gpio.c
4 * Single-state GPIO extcon driver based on extcon class
6 * Copyright (C) 2008 Google, Inc.
7 * Author: Mike Lockwood <lockwood@android.com>
9 * Modified by MyungJoo Ham <myungjoo.ham@samsung.com> to support extcon
10 * (originally switch class is supported)
12 * This software is licensed under the terms of the GNU General Public
13 * License version 2, as published by the Free Software Foundation, and
14 * may be copied, distributed, and modified under those terms.
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
23 #include <linux/module.h>
24 #include <linux/kernel.h>
25 #include <linux/init.h>
26 #include <linux/interrupt.h>
27 #include <linux/platform_device.h>
28 #include <linux/slab.h>
29 #include <linux/workqueue.h>
30 #include <linux/gpio.h>
31 #include <linux/extcon.h>
32 #include <linux/extcon/extcon-gpio.h>
34 struct gpio_extcon_data {
35 struct extcon_dev edev;
39 const char *state_off;
41 struct delayed_work work;
42 unsigned long debounce_jiffies;
45 static void gpio_extcon_work(struct work_struct *work)
48 struct gpio_extcon_data *data =
49 container_of(to_delayed_work(work), struct gpio_extcon_data,
52 state = gpio_get_value(data->gpio);
53 if (data->gpio_active_low)
55 extcon_set_state(&data->edev, state);
58 static irqreturn_t gpio_irq_handler(int irq, void *dev_id)
60 struct gpio_extcon_data *extcon_data = dev_id;
62 queue_delayed_work(system_power_efficient_wq, &extcon_data->work,
63 extcon_data->debounce_jiffies);
67 static ssize_t extcon_gpio_print_state(struct extcon_dev *edev, char *buf)
69 struct gpio_extcon_data *extcon_data =
70 container_of(edev, struct gpio_extcon_data, edev);
72 if (extcon_get_state(edev))
73 state = extcon_data->state_on;
75 state = extcon_data->state_off;
78 return sprintf(buf, "%s\n", state);
82 static int gpio_extcon_probe(struct platform_device *pdev)
84 struct gpio_extcon_platform_data *pdata = dev_get_platdata(&pdev->dev);
85 struct gpio_extcon_data *extcon_data;
90 if (!pdata->irq_flags) {
91 dev_err(&pdev->dev, "IRQ flag is not specified.\n");
95 extcon_data = devm_kzalloc(&pdev->dev, sizeof(struct gpio_extcon_data),
100 extcon_data->edev.name = pdata->name;
101 extcon_data->edev.dev.parent = &pdev->dev;
102 extcon_data->gpio = pdata->gpio;
103 extcon_data->gpio_active_low = pdata->gpio_active_low;
104 extcon_data->state_on = pdata->state_on;
105 extcon_data->state_off = pdata->state_off;
106 if (pdata->state_on && pdata->state_off)
107 extcon_data->edev.print_state = extcon_gpio_print_state;
109 ret = devm_gpio_request_one(&pdev->dev, extcon_data->gpio, GPIOF_DIR_IN,
114 if (pdata->debounce) {
115 ret = gpio_set_debounce(extcon_data->gpio,
116 pdata->debounce * 1000);
118 extcon_data->debounce_jiffies =
119 msecs_to_jiffies(pdata->debounce);
122 ret = extcon_dev_register(&extcon_data->edev);
126 INIT_DELAYED_WORK(&extcon_data->work, gpio_extcon_work);
128 extcon_data->irq = gpio_to_irq(extcon_data->gpio);
129 if (extcon_data->irq < 0) {
130 ret = extcon_data->irq;
134 ret = request_any_context_irq(extcon_data->irq, gpio_irq_handler,
135 pdata->irq_flags, pdev->name,
140 platform_set_drvdata(pdev, extcon_data);
141 /* Perform initial detection */
142 gpio_extcon_work(&extcon_data->work.work);
147 extcon_dev_unregister(&extcon_data->edev);
152 static int gpio_extcon_remove(struct platform_device *pdev)
154 struct gpio_extcon_data *extcon_data = platform_get_drvdata(pdev);
156 cancel_delayed_work_sync(&extcon_data->work);
157 free_irq(extcon_data->irq, extcon_data);
158 extcon_dev_unregister(&extcon_data->edev);
163 static struct platform_driver gpio_extcon_driver = {
164 .probe = gpio_extcon_probe,
165 .remove = gpio_extcon_remove,
167 .name = "extcon-gpio",
168 .owner = THIS_MODULE,
172 module_platform_driver(gpio_extcon_driver);
174 MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
175 MODULE_DESCRIPTION("GPIO extcon driver");
176 MODULE_LICENSE("GPL");