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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
George Cherian62364352014-09-09 09:44:34 +053023#include <linux/extcon.h>
24#include <linux/extcon/extcon-gpio.h>
25#include <linux/gpio.h>
MyungJoo Hambe483082012-04-20 14:16:23 +090026#include <linux/init.h>
27#include <linux/interrupt.h>
George Cherian62364352014-09-09 09:44:34 +053028#include <linux/kernel.h>
29#include <linux/module.h>
MyungJoo Hambe483082012-04-20 14:16:23 +090030#include <linux/platform_device.h>
31#include <linux/slab.h>
MyungJoo Hambe483082012-04-20 14:16:23 +090032#include <linux/workqueue.h>
MyungJoo Hambe483082012-04-20 14:16:23 +090033
34struct gpio_extcon_data {
Chanwoo Choi60cd62d2014-04-21 20:51:08 +090035 struct extcon_dev *edev;
MyungJoo Hambe483082012-04-20 14:16:23 +090036 unsigned gpio;
Guenter Roeck5bfbdc92013-09-12 08:49:54 +090037 bool gpio_active_low;
MyungJoo Hambe483082012-04-20 14:16:23 +090038 const char *state_on;
39 const char *state_off;
40 int irq;
41 struct delayed_work work;
42 unsigned long debounce_jiffies;
Rongjun Ying6544dfa2014-01-09 09:50:13 +090043 bool check_on_resume;
MyungJoo Hambe483082012-04-20 14:16:23 +090044};
45
46static void gpio_extcon_work(struct work_struct *work)
47{
48 int state;
49 struct gpio_extcon_data *data =
50 container_of(to_delayed_work(work), struct gpio_extcon_data,
51 work);
52
53 state = gpio_get_value(data->gpio);
Guenter Roeck5bfbdc92013-09-12 08:49:54 +090054 if (data->gpio_active_low)
55 state = !state;
Chanwoo Choi60cd62d2014-04-21 20:51:08 +090056 extcon_set_state(data->edev, state);
MyungJoo Hambe483082012-04-20 14:16:23 +090057}
58
59static irqreturn_t gpio_irq_handler(int irq, void *dev_id)
60{
61 struct gpio_extcon_data *extcon_data = dev_id;
62
Mark Brownd0db2e72013-07-19 18:47:34 +010063 queue_delayed_work(system_power_efficient_wq, &extcon_data->work,
MyungJoo Hambe483082012-04-20 14:16:23 +090064 extcon_data->debounce_jiffies);
65 return IRQ_HANDLED;
66}
67
68static ssize_t extcon_gpio_print_state(struct extcon_dev *edev, char *buf)
69{
Chanwoo Choi60cd62d2014-04-21 20:51:08 +090070 struct device *dev = edev->dev.parent;
71 struct gpio_extcon_data *extcon_data = dev_get_drvdata(dev);
MyungJoo Hambe483082012-04-20 14:16:23 +090072 const char *state;
Chanwoo Choi60cd62d2014-04-21 20:51:08 +090073
MyungJoo Hambe483082012-04-20 14:16:23 +090074 if (extcon_get_state(edev))
75 state = extcon_data->state_on;
76 else
77 state = extcon_data->state_off;
78
79 if (state)
80 return sprintf(buf, "%s\n", state);
81 return -EINVAL;
82}
83
Bill Pemberton44f34fd2012-11-19 13:23:21 -050084static int gpio_extcon_probe(struct platform_device *pdev)
MyungJoo Hambe483082012-04-20 14:16:23 +090085{
Jingoo Han7c0f65582013-09-11 13:22:18 +090086 struct gpio_extcon_platform_data *pdata = dev_get_platdata(&pdev->dev);
MyungJoo Hambe483082012-04-20 14:16:23 +090087 struct gpio_extcon_data *extcon_data;
Guenter Roeck10735142013-08-29 21:29:33 -070088 int ret;
MyungJoo Hambe483082012-04-20 14:16:23 +090089
90 if (!pdata)
91 return -EBUSY;
92 if (!pdata->irq_flags) {
93 dev_err(&pdev->dev, "IRQ flag is not specified.\n");
94 return -EINVAL;
95 }
96
97 extcon_data = devm_kzalloc(&pdev->dev, sizeof(struct gpio_extcon_data),
98 GFP_KERNEL);
99 if (!extcon_data)
100 return -ENOMEM;
101
Chanwoo Choi60cd62d2014-04-21 20:51:08 +0900102 extcon_data->edev = devm_extcon_dev_allocate(&pdev->dev, NULL);
103 if (IS_ERR(extcon_data->edev)) {
104 dev_err(&pdev->dev, "failed to allocate extcon device\n");
105 return -ENOMEM;
106 }
107 extcon_data->edev->name = pdata->name;
Chanwoo Choi60cd62d2014-04-21 20:51:08 +0900108
MyungJoo Hambe483082012-04-20 14:16:23 +0900109 extcon_data->gpio = pdata->gpio;
Guenter Roeck5bfbdc92013-09-12 08:49:54 +0900110 extcon_data->gpio_active_low = pdata->gpio_active_low;
MyungJoo Hambe483082012-04-20 14:16:23 +0900111 extcon_data->state_on = pdata->state_on;
112 extcon_data->state_off = pdata->state_off;
Rongjun Ying6544dfa2014-01-09 09:50:13 +0900113 extcon_data->check_on_resume = pdata->check_on_resume;
MyungJoo Hambe483082012-04-20 14:16:23 +0900114 if (pdata->state_on && pdata->state_off)
Chanwoo Choi60cd62d2014-04-21 20:51:08 +0900115 extcon_data->edev->print_state = extcon_gpio_print_state;
Guenter Roeck4288d9b2013-11-22 09:26:01 -0800116
117 ret = devm_gpio_request_one(&pdev->dev, extcon_data->gpio, GPIOF_DIR_IN,
118 pdev->name);
119 if (ret < 0)
120 return ret;
121
Guenter Roeck338de0c2013-09-10 19:16:18 -0700122 if (pdata->debounce) {
123 ret = gpio_set_debounce(extcon_data->gpio,
124 pdata->debounce * 1000);
125 if (ret < 0)
126 extcon_data->debounce_jiffies =
127 msecs_to_jiffies(pdata->debounce);
128 }
MyungJoo Hambe483082012-04-20 14:16:23 +0900129
Chanwoo Choi60cd62d2014-04-21 20:51:08 +0900130 ret = devm_extcon_dev_register(&pdev->dev, extcon_data->edev);
MyungJoo Hambe483082012-04-20 14:16:23 +0900131 if (ret < 0)
Axel Lin01eaf242012-06-16 11:56:24 +0800132 return ret;
MyungJoo Hambe483082012-04-20 14:16:23 +0900133
MyungJoo Hambe483082012-04-20 14:16:23 +0900134 INIT_DELAYED_WORK(&extcon_data->work, gpio_extcon_work);
135
136 extcon_data->irq = gpio_to_irq(extcon_data->gpio);
Sangjung Wood92c2f12014-04-21 19:10:10 +0900137 if (extcon_data->irq < 0)
138 return extcon_data->irq;
MyungJoo Hambe483082012-04-20 14:16:23 +0900139
140 ret = request_any_context_irq(extcon_data->irq, gpio_irq_handler,
141 pdata->irq_flags, pdev->name,
142 extcon_data);
143 if (ret < 0)
Sangjung Wood92c2f12014-04-21 19:10:10 +0900144 return ret;
MyungJoo Hambe483082012-04-20 14:16:23 +0900145
Axel Linb945f3f2012-06-16 11:55:18 +0800146 platform_set_drvdata(pdev, extcon_data);
MyungJoo Hambe483082012-04-20 14:16:23 +0900147 /* Perform initial detection */
148 gpio_extcon_work(&extcon_data->work.work);
149
150 return 0;
MyungJoo Hambe483082012-04-20 14:16:23 +0900151}
152
Bill Pemberton93ed0322012-11-19 13:25:49 -0500153static int gpio_extcon_remove(struct platform_device *pdev)
MyungJoo Hambe483082012-04-20 14:16:23 +0900154{
155 struct gpio_extcon_data *extcon_data = platform_get_drvdata(pdev);
156
157 cancel_delayed_work_sync(&extcon_data->work);
Axel Linb945f3f2012-06-16 11:55:18 +0800158 free_irq(extcon_data->irq, extcon_data);
MyungJoo Hambe483082012-04-20 14:16:23 +0900159
160 return 0;
161}
162
Rongjun Ying6544dfa2014-01-09 09:50:13 +0900163#ifdef CONFIG_PM_SLEEP
164static int gpio_extcon_resume(struct device *dev)
165{
166 struct gpio_extcon_data *extcon_data;
167
168 extcon_data = dev_get_drvdata(dev);
169 if (extcon_data->check_on_resume)
170 queue_delayed_work(system_power_efficient_wq,
171 &extcon_data->work, extcon_data->debounce_jiffies);
172
173 return 0;
174}
175#endif
176
Jingoo Han3cc731d2014-02-27 20:37:15 +0900177static SIMPLE_DEV_PM_OPS(gpio_extcon_pm_ops, NULL, gpio_extcon_resume);
Rongjun Ying6544dfa2014-01-09 09:50:13 +0900178
H Hartley Sweeten2878bda2012-05-02 15:38:44 -0700179static struct platform_driver gpio_extcon_driver = {
MyungJoo Hambe483082012-04-20 14:16:23 +0900180 .probe = gpio_extcon_probe,
Bill Pemberton5f7e2222012-11-19 13:20:06 -0500181 .remove = gpio_extcon_remove,
MyungJoo Hambe483082012-04-20 14:16:23 +0900182 .driver = {
183 .name = "extcon-gpio",
184 .owner = THIS_MODULE,
Rongjun Ying6544dfa2014-01-09 09:50:13 +0900185 .pm = &gpio_extcon_pm_ops,
MyungJoo Hambe483082012-04-20 14:16:23 +0900186 },
187};
188
H Hartley Sweeten2878bda2012-05-02 15:38:44 -0700189module_platform_driver(gpio_extcon_driver);
MyungJoo Hambe483082012-04-20 14:16:23 +0900190
191MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
192MODULE_DESCRIPTION("GPIO extcon driver");
193MODULE_LICENSE("GPL");