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be48308a MH |
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> | |
be48308a MH |
29 | #include <linux/workqueue.h> |
30 | #include <linux/gpio.h> | |
31 | #include <linux/extcon.h> | |
fd116066 | 32 | #include <linux/extcon/extcon-gpio.h> |
be48308a MH |
33 | |
34 | struct gpio_extcon_data { | |
35 | struct extcon_dev edev; | |
36 | unsigned gpio; | |
5bfbdc9c | 37 | bool gpio_active_low; |
be48308a MH |
38 | const char *state_on; |
39 | const char *state_off; | |
40 | int irq; | |
41 | struct delayed_work work; | |
42 | unsigned long debounce_jiffies; | |
43 | }; | |
44 | ||
45 | static 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 = gpio_get_value(data->gpio); | |
5bfbdc9c GR |
53 | if (data->gpio_active_low) |
54 | state = !state; | |
be48308a MH |
55 | extcon_set_state(&data->edev, state); |
56 | } | |
57 | ||
58 | static irqreturn_t gpio_irq_handler(int irq, void *dev_id) | |
59 | { | |
60 | struct gpio_extcon_data *extcon_data = dev_id; | |
61 | ||
d0db2e7a | 62 | queue_delayed_work(system_power_efficient_wq, &extcon_data->work, |
be48308a MH |
63 | extcon_data->debounce_jiffies); |
64 | return IRQ_HANDLED; | |
65 | } | |
66 | ||
67 | static ssize_t extcon_gpio_print_state(struct extcon_dev *edev, char *buf) | |
68 | { | |
69 | struct gpio_extcon_data *extcon_data = | |
70 | container_of(edev, struct gpio_extcon_data, edev); | |
71 | const char *state; | |
72 | if (extcon_get_state(edev)) | |
73 | state = extcon_data->state_on; | |
74 | else | |
75 | state = extcon_data->state_off; | |
76 | ||
77 | if (state) | |
78 | return sprintf(buf, "%s\n", state); | |
79 | return -EINVAL; | |
80 | } | |
81 | ||
44f34fd4 | 82 | static int gpio_extcon_probe(struct platform_device *pdev) |
be48308a | 83 | { |
7c0f6558 | 84 | struct gpio_extcon_platform_data *pdata = dev_get_platdata(&pdev->dev); |
be48308a | 85 | struct gpio_extcon_data *extcon_data; |
1073514b | 86 | int ret; |
be48308a MH |
87 | |
88 | if (!pdata) | |
89 | return -EBUSY; | |
90 | if (!pdata->irq_flags) { | |
91 | dev_err(&pdev->dev, "IRQ flag is not specified.\n"); | |
92 | return -EINVAL; | |
93 | } | |
94 | ||
95 | extcon_data = devm_kzalloc(&pdev->dev, sizeof(struct gpio_extcon_data), | |
96 | GFP_KERNEL); | |
97 | if (!extcon_data) | |
98 | return -ENOMEM; | |
99 | ||
100 | extcon_data->edev.name = pdata->name; | |
42d7d753 | 101 | extcon_data->edev.dev.parent = &pdev->dev; |
be48308a | 102 | extcon_data->gpio = pdata->gpio; |
5bfbdc9c | 103 | extcon_data->gpio_active_low = pdata->gpio_active_low; |
be48308a MH |
104 | extcon_data->state_on = pdata->state_on; |
105 | extcon_data->state_off = pdata->state_off; | |
106 | if (pdata->state_on && pdata->state_off) | |
107 | extcon_data->edev.print_state = extcon_gpio_print_state; | |
4288d9b8 GR |
108 | |
109 | ret = devm_gpio_request_one(&pdev->dev, extcon_data->gpio, GPIOF_DIR_IN, | |
110 | pdev->name); | |
111 | if (ret < 0) | |
112 | return ret; | |
113 | ||
338de0ca GR |
114 | if (pdata->debounce) { |
115 | ret = gpio_set_debounce(extcon_data->gpio, | |
116 | pdata->debounce * 1000); | |
117 | if (ret < 0) | |
118 | extcon_data->debounce_jiffies = | |
119 | msecs_to_jiffies(pdata->debounce); | |
120 | } | |
be48308a | 121 | |
42d7d753 | 122 | ret = extcon_dev_register(&extcon_data->edev); |
be48308a | 123 | if (ret < 0) |
01eaf245 | 124 | return ret; |
be48308a | 125 | |
be48308a MH |
126 | INIT_DELAYED_WORK(&extcon_data->work, gpio_extcon_work); |
127 | ||
128 | extcon_data->irq = gpio_to_irq(extcon_data->gpio); | |
129 | if (extcon_data->irq < 0) { | |
130 | ret = extcon_data->irq; | |
01eaf245 | 131 | goto err; |
be48308a MH |
132 | } |
133 | ||
134 | ret = request_any_context_irq(extcon_data->irq, gpio_irq_handler, | |
135 | pdata->irq_flags, pdev->name, | |
136 | extcon_data); | |
137 | if (ret < 0) | |
01eaf245 | 138 | goto err; |
be48308a | 139 | |
b945f3fa | 140 | platform_set_drvdata(pdev, extcon_data); |
be48308a MH |
141 | /* Perform initial detection */ |
142 | gpio_extcon_work(&extcon_data->work.work); | |
143 | ||
144 | return 0; | |
145 | ||
01eaf245 | 146 | err: |
be48308a | 147 | extcon_dev_unregister(&extcon_data->edev); |
be48308a MH |
148 | |
149 | return ret; | |
150 | } | |
151 | ||
93ed0327 | 152 | static int gpio_extcon_remove(struct platform_device *pdev) |
be48308a MH |
153 | { |
154 | struct gpio_extcon_data *extcon_data = platform_get_drvdata(pdev); | |
155 | ||
156 | cancel_delayed_work_sync(&extcon_data->work); | |
b945f3fa | 157 | free_irq(extcon_data->irq, extcon_data); |
be48308a | 158 | extcon_dev_unregister(&extcon_data->edev); |
be48308a MH |
159 | |
160 | return 0; | |
161 | } | |
162 | ||
2878bda8 | 163 | static struct platform_driver gpio_extcon_driver = { |
be48308a | 164 | .probe = gpio_extcon_probe, |
5f7e2228 | 165 | .remove = gpio_extcon_remove, |
be48308a MH |
166 | .driver = { |
167 | .name = "extcon-gpio", | |
168 | .owner = THIS_MODULE, | |
169 | }, | |
170 | }; | |
171 | ||
2878bda8 | 172 | module_platform_driver(gpio_extcon_driver); |
be48308a MH |
173 | |
174 | MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>"); | |
175 | MODULE_DESCRIPTION("GPIO extcon driver"); | |
176 | MODULE_LICENSE("GPL"); |