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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");
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-provider.h>
21#include <linux/gpio/consumer.h>
22#include <linux/init.h>
23#include <linux/interrupt.h>
24#include <linux/kernel.h>
25#include <linux/module.h>
26#include <linux/platform_device.h>
27#include <linux/slab.h>
28#include <linux/workqueue.h>
29
30/**
31 * struct gpio_extcon_data - A simple GPIO-controlled extcon device state container.
32 * @edev: Extcon device.
33 * @irq: Interrupt line for the external connector.
34 * @work: Work fired by the interrupt.
35 * @debounce_jiffies: Number of jiffies to wait for the GPIO to stabilize, from the debounce
36 * value.
37 * @gpiod: GPIO descriptor for this external connector.
38 * @extcon_id: The unique id of specific external connector.
39 * @debounce: Debounce time for GPIO IRQ in ms.
40 * @irq_flags: IRQ Flags (e.g., IRQF_TRIGGER_LOW).
41 * @check_on_resume: Boolean describing whether to check the state of gpio
42 * while resuming from sleep.
43 */
44struct gpio_extcon_data {
45 struct extcon_dev *edev;
46 int irq;
47 struct delayed_work work;
48 unsigned long debounce_jiffies;
49 struct gpio_desc *gpiod;
50 unsigned int extcon_id;
51 unsigned long debounce;
52 unsigned long irq_flags;
53 bool check_on_resume;
54};
55
56static void gpio_extcon_work(struct work_struct *work)
57{
58 int state;
59 struct gpio_extcon_data *data =
60 container_of(to_delayed_work(work), struct gpio_extcon_data,
61 work);
62
63 state = gpiod_get_value_cansleep(data->gpiod);
64 extcon_set_state_sync(data->edev, data->extcon_id, state);
65}
66
67static irqreturn_t gpio_irq_handler(int irq, void *dev_id)
68{
69 struct gpio_extcon_data *data = dev_id;
70
71 queue_delayed_work(system_power_efficient_wq, &data->work,
72 data->debounce_jiffies);
73 return IRQ_HANDLED;
74}
75
76static int gpio_extcon_probe(struct platform_device *pdev)
77{
78 struct gpio_extcon_data *data;
79 struct device *dev = &pdev->dev;
80 int ret;
81
82 data = devm_kzalloc(dev, sizeof(struct gpio_extcon_data), GFP_KERNEL);
83 if (!data)
84 return -ENOMEM;
85
86 /*
87 * FIXME: extcon_id represents the unique identifier of external
88 * connectors such as EXTCON_USB, EXTCON_DISP_HDMI and so on. extcon_id
89 * is necessary to register the extcon device. But, it's not yet
90 * developed to get the extcon id from device-tree or others.
91 * On later, it have to be solved.
92 */
93 if (!data->irq_flags || data->extcon_id > EXTCON_NONE)
94 return -EINVAL;
95
96 data->gpiod = devm_gpiod_get(dev, "extcon", GPIOD_IN);
97 if (IS_ERR(data->gpiod))
98 return PTR_ERR(data->gpiod);
99 data->irq = gpiod_to_irq(data->gpiod);
100 if (data->irq <= 0)
101 return data->irq;
102
103 /* Allocate the memory of extcon devie and register extcon device */
104 data->edev = devm_extcon_dev_allocate(dev, &data->extcon_id);
105 if (IS_ERR(data->edev)) {
106 dev_err(dev, "failed to allocate extcon device\n");
107 return -ENOMEM;
108 }
109
110 ret = devm_extcon_dev_register(dev, data->edev);
111 if (ret < 0)
112 return ret;
113
114 INIT_DELAYED_WORK(&data->work, gpio_extcon_work);
115
116 /*
117 * Request the interrupt of gpio to detect whether external connector
118 * is attached or detached.
119 */
120 ret = devm_request_any_context_irq(dev, data->irq,
121 gpio_irq_handler, data->irq_flags,
122 pdev->name, data);
123 if (ret < 0)
124 return ret;
125
126 platform_set_drvdata(pdev, data);
127 /* Perform initial detection */
128 gpio_extcon_work(&data->work.work);
129
130 return 0;
131}
132
133static int gpio_extcon_remove(struct platform_device *pdev)
134{
135 struct gpio_extcon_data *data = platform_get_drvdata(pdev);
136
137 cancel_delayed_work_sync(&data->work);
138
139 return 0;
140}
141
142#ifdef CONFIG_PM_SLEEP
143static int gpio_extcon_resume(struct device *dev)
144{
145 struct gpio_extcon_data *data;
146
147 data = dev_get_drvdata(dev);
148 if (data->check_on_resume)
149 queue_delayed_work(system_power_efficient_wq,
150 &data->work, data->debounce_jiffies);
151
152 return 0;
153}
154#endif
155
156static SIMPLE_DEV_PM_OPS(gpio_extcon_pm_ops, NULL, gpio_extcon_resume);
157
158static struct platform_driver gpio_extcon_driver = {
159 .probe = gpio_extcon_probe,
160 .remove = gpio_extcon_remove,
161 .driver = {
162 .name = "extcon-gpio",
163 .pm = &gpio_extcon_pm_ops,
164 },
165};
166
167module_platform_driver(gpio_extcon_driver);
168
169MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
170MODULE_DESCRIPTION("GPIO extcon driver");
171MODULE_LICENSE("GPL");