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MyungJoo Hambe483082012-04-20 14:16:23 +09001/*
2 * drivers/extcon/extcon_gpio.c
3 *
4 * Single-state GPIO extcon driver based on extcon class
5 *
6 * Copyright (C) 2008 Google, Inc.
7 * Author: Mike Lockwood <lockwood@android.com>
8 *
9 * Modified by MyungJoo Ham <myungjoo.ham@samsung.com> to support extcon
10 * (originally switch class is supported)
11 *
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.
15 *
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.
20 *
21*/
22
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>
MyungJoo Hambe483082012-04-20 14:16:23 +090029#include <linux/workqueue.h>
30#include <linux/gpio.h>
31#include <linux/extcon.h>
Chanwoo Choifd116062013-02-13 18:35:00 +090032#include <linux/extcon/extcon-gpio.h>
MyungJoo Hambe483082012-04-20 14:16:23 +090033
34struct gpio_extcon_data {
35 struct extcon_dev edev;
36 unsigned gpio;
37 const char *state_on;
38 const char *state_off;
39 int irq;
40 struct delayed_work work;
41 unsigned long debounce_jiffies;
42};
43
44static void gpio_extcon_work(struct work_struct *work)
45{
46 int state;
47 struct gpio_extcon_data *data =
48 container_of(to_delayed_work(work), struct gpio_extcon_data,
49 work);
50
51 state = gpio_get_value(data->gpio);
52 extcon_set_state(&data->edev, state);
53}
54
55static irqreturn_t gpio_irq_handler(int irq, void *dev_id)
56{
57 struct gpio_extcon_data *extcon_data = dev_id;
58
Mark Brownd0db2e72013-07-19 18:47:34 +010059 queue_delayed_work(system_power_efficient_wq, &extcon_data->work,
MyungJoo Hambe483082012-04-20 14:16:23 +090060 extcon_data->debounce_jiffies);
61 return IRQ_HANDLED;
62}
63
64static ssize_t extcon_gpio_print_state(struct extcon_dev *edev, char *buf)
65{
66 struct gpio_extcon_data *extcon_data =
67 container_of(edev, struct gpio_extcon_data, edev);
68 const char *state;
69 if (extcon_get_state(edev))
70 state = extcon_data->state_on;
71 else
72 state = extcon_data->state_off;
73
74 if (state)
75 return sprintf(buf, "%s\n", state);
76 return -EINVAL;
77}
78
Bill Pemberton44f34fd2012-11-19 13:23:21 -050079static int gpio_extcon_probe(struct platform_device *pdev)
MyungJoo Hambe483082012-04-20 14:16:23 +090080{
81 struct gpio_extcon_platform_data *pdata = pdev->dev.platform_data;
82 struct gpio_extcon_data *extcon_data;
83 int ret = 0;
84
85 if (!pdata)
86 return -EBUSY;
87 if (!pdata->irq_flags) {
88 dev_err(&pdev->dev, "IRQ flag is not specified.\n");
89 return -EINVAL;
90 }
91
92 extcon_data = devm_kzalloc(&pdev->dev, sizeof(struct gpio_extcon_data),
93 GFP_KERNEL);
94 if (!extcon_data)
95 return -ENOMEM;
96
97 extcon_data->edev.name = pdata->name;
98 extcon_data->gpio = pdata->gpio;
99 extcon_data->state_on = pdata->state_on;
100 extcon_data->state_off = pdata->state_off;
101 if (pdata->state_on && pdata->state_off)
102 extcon_data->edev.print_state = extcon_gpio_print_state;
103 extcon_data->debounce_jiffies = msecs_to_jiffies(pdata->debounce);
104
105 ret = extcon_dev_register(&extcon_data->edev, &pdev->dev);
106 if (ret < 0)
Axel Lin01eaf242012-06-16 11:56:24 +0800107 return ret;
MyungJoo Hambe483082012-04-20 14:16:23 +0900108
Axel Lin7b7e9952012-07-24 09:26:57 +0800109 ret = devm_gpio_request_one(&pdev->dev, extcon_data->gpio, GPIOF_DIR_IN,
110 pdev->name);
MyungJoo Hambe483082012-04-20 14:16:23 +0900111 if (ret < 0)
Axel Lin01eaf242012-06-16 11:56:24 +0800112 goto err;
MyungJoo Hambe483082012-04-20 14:16:23 +0900113
114 INIT_DELAYED_WORK(&extcon_data->work, gpio_extcon_work);
115
116 extcon_data->irq = gpio_to_irq(extcon_data->gpio);
117 if (extcon_data->irq < 0) {
118 ret = extcon_data->irq;
Axel Lin01eaf242012-06-16 11:56:24 +0800119 goto err;
MyungJoo Hambe483082012-04-20 14:16:23 +0900120 }
121
122 ret = request_any_context_irq(extcon_data->irq, gpio_irq_handler,
123 pdata->irq_flags, pdev->name,
124 extcon_data);
125 if (ret < 0)
Axel Lin01eaf242012-06-16 11:56:24 +0800126 goto err;
MyungJoo Hambe483082012-04-20 14:16:23 +0900127
Axel Linb945f3f2012-06-16 11:55:18 +0800128 platform_set_drvdata(pdev, extcon_data);
MyungJoo Hambe483082012-04-20 14:16:23 +0900129 /* Perform initial detection */
130 gpio_extcon_work(&extcon_data->work.work);
131
132 return 0;
133
Axel Lin01eaf242012-06-16 11:56:24 +0800134err:
MyungJoo Hambe483082012-04-20 14:16:23 +0900135 extcon_dev_unregister(&extcon_data->edev);
MyungJoo Hambe483082012-04-20 14:16:23 +0900136
137 return ret;
138}
139
Bill Pemberton93ed0322012-11-19 13:25:49 -0500140static int gpio_extcon_remove(struct platform_device *pdev)
MyungJoo Hambe483082012-04-20 14:16:23 +0900141{
142 struct gpio_extcon_data *extcon_data = platform_get_drvdata(pdev);
143
144 cancel_delayed_work_sync(&extcon_data->work);
Axel Linb945f3f2012-06-16 11:55:18 +0800145 free_irq(extcon_data->irq, extcon_data);
MyungJoo Hambe483082012-04-20 14:16:23 +0900146 extcon_dev_unregister(&extcon_data->edev);
MyungJoo Hambe483082012-04-20 14:16:23 +0900147
148 return 0;
149}
150
H Hartley Sweeten2878bda2012-05-02 15:38:44 -0700151static struct platform_driver gpio_extcon_driver = {
MyungJoo Hambe483082012-04-20 14:16:23 +0900152 .probe = gpio_extcon_probe,
Bill Pemberton5f7e2222012-11-19 13:20:06 -0500153 .remove = gpio_extcon_remove,
MyungJoo Hambe483082012-04-20 14:16:23 +0900154 .driver = {
155 .name = "extcon-gpio",
156 .owner = THIS_MODULE,
157 },
158};
159
H Hartley Sweeten2878bda2012-05-02 15:38:44 -0700160module_platform_driver(gpio_extcon_driver);
MyungJoo Hambe483082012-04-20 14:16:23 +0900161
162MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
163MODULE_DESCRIPTION("GPIO extcon driver");
164MODULE_LICENSE("GPL");