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1/*
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>
29#include <linux/workqueue.h>
30#include <linux/gpio.h>
31#include <linux/extcon.h>
32#include <linux/extcon/extcon-gpio.h>
33
34struct gpio_extcon_data {
35 struct extcon_dev edev;
36 unsigned gpio;
37 bool gpio_active_low;
38 const char *state_on;
39 const char *state_off;
40 int irq;
41 struct delayed_work work;
42 unsigned long debounce_jiffies;
43 bool check_on_resume;
44};
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);
54 if (data->gpio_active_low)
55 state = !state;
56 extcon_set_state(&data->edev, state);
57}
58
59static irqreturn_t gpio_irq_handler(int irq, void *dev_id)
60{
61 struct gpio_extcon_data *extcon_data = dev_id;
62
63 queue_delayed_work(system_power_efficient_wq, &extcon_data->work,
64 extcon_data->debounce_jiffies);
65 return IRQ_HANDLED;
66}
67
68static ssize_t extcon_gpio_print_state(struct extcon_dev *edev, char *buf)
69{
70 struct gpio_extcon_data *extcon_data =
71 container_of(edev, struct gpio_extcon_data, edev);
72 const char *state;
73 if (extcon_get_state(edev))
74 state = extcon_data->state_on;
75 else
76 state = extcon_data->state_off;
77
78 if (state)
79 return sprintf(buf, "%s\n", state);
80 return -EINVAL;
81}
82
83static int gpio_extcon_probe(struct platform_device *pdev)
84{
85 struct gpio_extcon_platform_data *pdata = dev_get_platdata(&pdev->dev);
86 struct gpio_extcon_data *extcon_data;
87 int ret;
88
89 if (!pdata)
90 return -EBUSY;
91 if (!pdata->irq_flags) {
92 dev_err(&pdev->dev, "IRQ flag is not specified.\n");
93 return -EINVAL;
94 }
95
96 extcon_data = devm_kzalloc(&pdev->dev, sizeof(struct gpio_extcon_data),
97 GFP_KERNEL);
98 if (!extcon_data)
99 return -ENOMEM;
100
101 extcon_data->edev.name = pdata->name;
102 extcon_data->edev.dev.parent = &pdev->dev;
103 extcon_data->gpio = pdata->gpio;
104 extcon_data->gpio_active_low = pdata->gpio_active_low;
105 extcon_data->state_on = pdata->state_on;
106 extcon_data->state_off = pdata->state_off;
107 extcon_data->check_on_resume = pdata->check_on_resume;
108 if (pdata->state_on && pdata->state_off)
109 extcon_data->edev.print_state = extcon_gpio_print_state;
110
111 ret = devm_gpio_request_one(&pdev->dev, extcon_data->gpio, GPIOF_DIR_IN,
112 pdev->name);
113 if (ret < 0)
114 return ret;
115
116 if (pdata->debounce) {
117 ret = gpio_set_debounce(extcon_data->gpio,
118 pdata->debounce * 1000);
119 if (ret < 0)
120 extcon_data->debounce_jiffies =
121 msecs_to_jiffies(pdata->debounce);
122 }
123
124 ret = extcon_dev_register(&extcon_data->edev);
125 if (ret < 0)
126 return ret;
127
128 INIT_DELAYED_WORK(&extcon_data->work, gpio_extcon_work);
129
130 extcon_data->irq = gpio_to_irq(extcon_data->gpio);
131 if (extcon_data->irq < 0) {
132 ret = extcon_data->irq;
133 goto err;
134 }
135
136 ret = request_any_context_irq(extcon_data->irq, gpio_irq_handler,
137 pdata->irq_flags, pdev->name,
138 extcon_data);
139 if (ret < 0)
140 goto err;
141
142 platform_set_drvdata(pdev, extcon_data);
143 /* Perform initial detection */
144 gpio_extcon_work(&extcon_data->work.work);
145
146 return 0;
147
148err:
149 extcon_dev_unregister(&extcon_data->edev);
150
151 return ret;
152}
153
154static int gpio_extcon_remove(struct platform_device *pdev)
155{
156 struct gpio_extcon_data *extcon_data = platform_get_drvdata(pdev);
157
158 cancel_delayed_work_sync(&extcon_data->work);
159 free_irq(extcon_data->irq, extcon_data);
160 extcon_dev_unregister(&extcon_data->edev);
161
162 return 0;
163}
164
165#ifdef CONFIG_PM_SLEEP
166static int gpio_extcon_resume(struct device *dev)
167{
168 struct gpio_extcon_data *extcon_data;
169
170 extcon_data = dev_get_drvdata(dev);
171 if (extcon_data->check_on_resume)
172 queue_delayed_work(system_power_efficient_wq,
173 &extcon_data->work, extcon_data->debounce_jiffies);
174
175 return 0;
176}
177#endif
178
179static SIMPLE_DEV_PM_OPS(gpio_extcon_pm_ops, NULL, gpio_extcon_resume);
180
181static struct platform_driver gpio_extcon_driver = {
182 .probe = gpio_extcon_probe,
183 .remove = gpio_extcon_remove,
184 .driver = {
185 .name = "extcon-gpio",
186 .owner = THIS_MODULE,
187 .pm = &gpio_extcon_pm_ops,
188 },
189};
190
191module_platform_driver(gpio_extcon_driver);
192
193MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
194MODULE_DESCRIPTION("GPIO extcon driver");
195MODULE_LICENSE("GPL");
1/*
2 * extcon_gpio.c - Single-state GPIO extcon driver based on extcon class
3 *
4 * Copyright (C) 2008 Google, Inc.
5 * Author: Mike Lockwood <lockwood@android.com>
6 *
7 * Modified by MyungJoo Ham <myungjoo.ham@samsung.com> to support extcon
8 * (originally switch class is supported)
9 *
10 * This software is licensed under the terms of the GNU General Public
11 * License version 2, as published by the Free Software Foundation, and
12 * may be copied, distributed, and modified under those terms.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 */
19
20#include <linux/extcon.h>
21#include <linux/extcon/extcon-gpio.h>
22#include <linux/gpio.h>
23#include <linux/gpio/consumer.h>
24#include <linux/init.h>
25#include <linux/interrupt.h>
26#include <linux/kernel.h>
27#include <linux/module.h>
28#include <linux/platform_device.h>
29#include <linux/slab.h>
30#include <linux/workqueue.h>
31
32struct gpio_extcon_data {
33 struct extcon_dev *edev;
34 int irq;
35 struct delayed_work work;
36 unsigned long debounce_jiffies;
37
38 struct gpio_desc *id_gpiod;
39 struct gpio_extcon_pdata *pdata;
40};
41
42static void gpio_extcon_work(struct work_struct *work)
43{
44 int state;
45 struct gpio_extcon_data *data =
46 container_of(to_delayed_work(work), struct gpio_extcon_data,
47 work);
48
49 state = gpiod_get_value_cansleep(data->id_gpiod);
50 if (data->pdata->gpio_active_low)
51 state = !state;
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 *data = dev_id;
58
59 queue_delayed_work(system_power_efficient_wq, &data->work,
60 data->debounce_jiffies);
61 return IRQ_HANDLED;
62}
63
64static int gpio_extcon_init(struct device *dev, struct gpio_extcon_data *data)
65{
66 struct gpio_extcon_pdata *pdata = data->pdata;
67 int ret;
68
69 ret = devm_gpio_request_one(dev, pdata->gpio, GPIOF_DIR_IN,
70 dev_name(dev));
71 if (ret < 0)
72 return ret;
73
74 data->id_gpiod = gpio_to_desc(pdata->gpio);
75 if (!data->id_gpiod)
76 return -EINVAL;
77
78 if (pdata->debounce) {
79 ret = gpiod_set_debounce(data->id_gpiod,
80 pdata->debounce * 1000);
81 if (ret < 0)
82 data->debounce_jiffies =
83 msecs_to_jiffies(pdata->debounce);
84 }
85
86 data->irq = gpiod_to_irq(data->id_gpiod);
87 if (data->irq < 0)
88 return data->irq;
89
90 return 0;
91}
92
93static int gpio_extcon_probe(struct platform_device *pdev)
94{
95 struct gpio_extcon_pdata *pdata = dev_get_platdata(&pdev->dev);
96 struct gpio_extcon_data *data;
97 int ret;
98
99 if (!pdata)
100 return -EBUSY;
101 if (!pdata->irq_flags || pdata->extcon_id > EXTCON_NONE)
102 return -EINVAL;
103
104 data = devm_kzalloc(&pdev->dev, sizeof(struct gpio_extcon_data),
105 GFP_KERNEL);
106 if (!data)
107 return -ENOMEM;
108 data->pdata = pdata;
109
110 /* Initialize the gpio */
111 ret = gpio_extcon_init(&pdev->dev, data);
112 if (ret < 0)
113 return ret;
114
115 /* Allocate the memory of extcon devie and register extcon device */
116 data->edev = devm_extcon_dev_allocate(&pdev->dev, &pdata->extcon_id);
117 if (IS_ERR(data->edev)) {
118 dev_err(&pdev->dev, "failed to allocate extcon device\n");
119 return -ENOMEM;
120 }
121
122 ret = devm_extcon_dev_register(&pdev->dev, data->edev);
123 if (ret < 0)
124 return ret;
125
126 INIT_DELAYED_WORK(&data->work, gpio_extcon_work);
127
128 /*
129 * Request the interrupt of gpio to detect whether external connector
130 * is attached or detached.
131 */
132 ret = devm_request_any_context_irq(&pdev->dev, data->irq,
133 gpio_irq_handler, pdata->irq_flags,
134 pdev->name, data);
135 if (ret < 0)
136 return ret;
137
138 platform_set_drvdata(pdev, data);
139 /* Perform initial detection */
140 gpio_extcon_work(&data->work.work);
141
142 return 0;
143}
144
145static int gpio_extcon_remove(struct platform_device *pdev)
146{
147 struct gpio_extcon_data *data = platform_get_drvdata(pdev);
148
149 cancel_delayed_work_sync(&data->work);
150
151 return 0;
152}
153
154#ifdef CONFIG_PM_SLEEP
155static int gpio_extcon_resume(struct device *dev)
156{
157 struct gpio_extcon_data *data;
158
159 data = dev_get_drvdata(dev);
160 if (data->pdata->check_on_resume)
161 queue_delayed_work(system_power_efficient_wq,
162 &data->work, data->debounce_jiffies);
163
164 return 0;
165}
166#endif
167
168static SIMPLE_DEV_PM_OPS(gpio_extcon_pm_ops, NULL, gpio_extcon_resume);
169
170static struct platform_driver gpio_extcon_driver = {
171 .probe = gpio_extcon_probe,
172 .remove = gpio_extcon_remove,
173 .driver = {
174 .name = "extcon-gpio",
175 .pm = &gpio_extcon_pm_ops,
176 },
177};
178
179module_platform_driver(gpio_extcon_driver);
180
181MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
182MODULE_DESCRIPTION("GPIO extcon driver");
183MODULE_LICENSE("GPL");