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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * extcon_gpio.c - Single-state GPIO extcon driver based on extcon class
4 *
5 * Copyright (C) 2008 Google, Inc.
6 * Author: Mike Lockwood <lockwood@android.com>
7 *
8 * Modified by MyungJoo Ham <myungjoo.ham@samsung.com> to support extcon
9 * (originally switch class is supported)
10 */
11
12#include <linux/devm-helpers.h>
13#include <linux/extcon-provider.h>
14#include <linux/gpio/consumer.h>
15#include <linux/init.h>
16#include <linux/interrupt.h>
17#include <linux/kernel.h>
18#include <linux/module.h>
19#include <linux/platform_device.h>
20#include <linux/slab.h>
21#include <linux/workqueue.h>
22
23/**
24 * struct gpio_extcon_data - A simple GPIO-controlled extcon device state container.
25 * @edev: Extcon device.
26 * @work: Work fired by the interrupt.
27 * @debounce_jiffies: Number of jiffies to wait for the GPIO to stabilize, from the debounce
28 * value.
29 * @gpiod: GPIO descriptor for this external connector.
30 * @extcon_id: The unique id of specific external connector.
31 * @debounce: Debounce time for GPIO IRQ in ms.
32 * @check_on_resume: Boolean describing whether to check the state of gpio
33 * while resuming from sleep.
34 */
35struct gpio_extcon_data {
36 struct extcon_dev *edev;
37 struct delayed_work work;
38 unsigned long debounce_jiffies;
39 struct gpio_desc *gpiod;
40 unsigned int extcon_id;
41 unsigned long debounce;
42 bool check_on_resume;
43};
44
45static void gpio_extcon_work(struct work_struct *work)
46{
47 int state;
48 struct gpio_extcon_data *data =
49 container_of(to_delayed_work(work), struct gpio_extcon_data,
50 work);
51
52 state = gpiod_get_value_cansleep(data->gpiod);
53 extcon_set_state_sync(data->edev, data->extcon_id, state);
54}
55
56static irqreturn_t gpio_irq_handler(int irq, void *dev_id)
57{
58 struct gpio_extcon_data *data = dev_id;
59
60 queue_delayed_work(system_power_efficient_wq, &data->work,
61 data->debounce_jiffies);
62 return IRQ_HANDLED;
63}
64
65static int gpio_extcon_probe(struct platform_device *pdev)
66{
67 struct gpio_extcon_data *data;
68 struct device *dev = &pdev->dev;
69 unsigned long irq_flags;
70 int irq;
71 int ret;
72
73 data = devm_kzalloc(dev, sizeof(struct gpio_extcon_data), GFP_KERNEL);
74 if (!data)
75 return -ENOMEM;
76
77 /*
78 * FIXME: extcon_id represents the unique identifier of external
79 * connectors such as EXTCON_USB, EXTCON_DISP_HDMI and so on. extcon_id
80 * is necessary to register the extcon device. But, it's not yet
81 * developed to get the extcon id from device-tree or others.
82 * On later, it have to be solved.
83 */
84 if (data->extcon_id > EXTCON_NONE)
85 return -EINVAL;
86
87 data->gpiod = devm_gpiod_get(dev, "extcon", GPIOD_IN);
88 if (IS_ERR(data->gpiod))
89 return PTR_ERR(data->gpiod);
90 irq = gpiod_to_irq(data->gpiod);
91 if (irq <= 0)
92 return irq;
93
94 /*
95 * It is unlikely that this is an acknowledged interrupt that goes
96 * away after handling, what we are looking for are falling edges
97 * if the signal is active low, and rising edges if the signal is
98 * active high.
99 */
100 if (gpiod_is_active_low(data->gpiod))
101 irq_flags = IRQF_TRIGGER_FALLING;
102 else
103 irq_flags = IRQF_TRIGGER_RISING;
104
105 /* Allocate the memory of extcon devie and register extcon device */
106 data->edev = devm_extcon_dev_allocate(dev, &data->extcon_id);
107 if (IS_ERR(data->edev)) {
108 dev_err(dev, "failed to allocate extcon device\n");
109 return -ENOMEM;
110 }
111
112 ret = devm_extcon_dev_register(dev, data->edev);
113 if (ret < 0)
114 return ret;
115
116 ret = devm_delayed_work_autocancel(dev, &data->work, gpio_extcon_work);
117 if (ret)
118 return ret;
119
120 /*
121 * Request the interrupt of gpio to detect whether external connector
122 * is attached or detached.
123 */
124 ret = devm_request_any_context_irq(dev, irq,
125 gpio_irq_handler, irq_flags,
126 pdev->name, data);
127 if (ret < 0)
128 return ret;
129
130 platform_set_drvdata(pdev, data);
131 /* Perform initial detection */
132 gpio_extcon_work(&data->work.work);
133
134 return 0;
135}
136
137#ifdef CONFIG_PM_SLEEP
138static int gpio_extcon_resume(struct device *dev)
139{
140 struct gpio_extcon_data *data;
141
142 data = dev_get_drvdata(dev);
143 if (data->check_on_resume)
144 queue_delayed_work(system_power_efficient_wq,
145 &data->work, data->debounce_jiffies);
146
147 return 0;
148}
149#endif
150
151static SIMPLE_DEV_PM_OPS(gpio_extcon_pm_ops, NULL, gpio_extcon_resume);
152
153static struct platform_driver gpio_extcon_driver = {
154 .probe = gpio_extcon_probe,
155 .driver = {
156 .name = "extcon-gpio",
157 .pm = &gpio_extcon_pm_ops,
158 },
159};
160
161module_platform_driver(gpio_extcon_driver);
162
163MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
164MODULE_DESCRIPTION("GPIO extcon driver");
165MODULE_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");