Commit | Line | Data |
---|---|---|
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; | |
37 | const char *state_on; | |
38 | const char *state_off; | |
39 | int irq; | |
40 | struct delayed_work work; | |
41 | unsigned long debounce_jiffies; | |
42 | }; | |
43 | ||
44 | static void gpio_extcon_work(struct work_struct *work) | |
45 | { | |
46 | int state; | |
47 | struct gpio_extcon_data *data = | |
48 | container_of(to_delayed_work(work), struct gpio_extcon_data, | |
49 | work); | |
50 | ||
51 | state = gpio_get_value(data->gpio); | |
52 | extcon_set_state(&data->edev, state); | |
53 | } | |
54 | ||
55 | static irqreturn_t gpio_irq_handler(int irq, void *dev_id) | |
56 | { | |
57 | struct gpio_extcon_data *extcon_data = dev_id; | |
58 | ||
59 | schedule_delayed_work(&extcon_data->work, | |
60 | extcon_data->debounce_jiffies); | |
61 | return IRQ_HANDLED; | |
62 | } | |
63 | ||
64 | static ssize_t extcon_gpio_print_state(struct extcon_dev *edev, char *buf) | |
65 | { | |
66 | struct gpio_extcon_data *extcon_data = | |
67 | container_of(edev, struct gpio_extcon_data, edev); | |
68 | const char *state; | |
69 | if (extcon_get_state(edev)) | |
70 | state = extcon_data->state_on; | |
71 | else | |
72 | state = extcon_data->state_off; | |
73 | ||
74 | if (state) | |
75 | return sprintf(buf, "%s\n", state); | |
76 | return -EINVAL; | |
77 | } | |
78 | ||
44f34fd4 | 79 | static int gpio_extcon_probe(struct platform_device *pdev) |
be48308a MH |
80 | { |
81 | struct gpio_extcon_platform_data *pdata = pdev->dev.platform_data; | |
82 | struct gpio_extcon_data *extcon_data; | |
83 | int ret = 0; | |
84 | ||
85 | if (!pdata) | |
86 | return -EBUSY; | |
87 | if (!pdata->irq_flags) { | |
88 | dev_err(&pdev->dev, "IRQ flag is not specified.\n"); | |
89 | return -EINVAL; | |
90 | } | |
91 | ||
92 | extcon_data = devm_kzalloc(&pdev->dev, sizeof(struct gpio_extcon_data), | |
93 | GFP_KERNEL); | |
94 | if (!extcon_data) | |
95 | return -ENOMEM; | |
96 | ||
97 | extcon_data->edev.name = pdata->name; | |
98 | extcon_data->gpio = pdata->gpio; | |
99 | extcon_data->state_on = pdata->state_on; | |
100 | extcon_data->state_off = pdata->state_off; | |
101 | if (pdata->state_on && pdata->state_off) | |
102 | extcon_data->edev.print_state = extcon_gpio_print_state; | |
103 | extcon_data->debounce_jiffies = msecs_to_jiffies(pdata->debounce); | |
104 | ||
105 | ret = extcon_dev_register(&extcon_data->edev, &pdev->dev); | |
106 | if (ret < 0) | |
01eaf245 | 107 | return ret; |
be48308a | 108 | |
7b7e995d AL |
109 | ret = devm_gpio_request_one(&pdev->dev, extcon_data->gpio, GPIOF_DIR_IN, |
110 | pdev->name); | |
be48308a | 111 | if (ret < 0) |
01eaf245 | 112 | goto err; |
be48308a MH |
113 | |
114 | INIT_DELAYED_WORK(&extcon_data->work, gpio_extcon_work); | |
115 | ||
116 | extcon_data->irq = gpio_to_irq(extcon_data->gpio); | |
117 | if (extcon_data->irq < 0) { | |
118 | ret = extcon_data->irq; | |
01eaf245 | 119 | goto err; |
be48308a MH |
120 | } |
121 | ||
122 | ret = request_any_context_irq(extcon_data->irq, gpio_irq_handler, | |
123 | pdata->irq_flags, pdev->name, | |
124 | extcon_data); | |
125 | if (ret < 0) | |
01eaf245 | 126 | goto err; |
be48308a | 127 | |
b945f3fa | 128 | platform_set_drvdata(pdev, extcon_data); |
be48308a MH |
129 | /* Perform initial detection */ |
130 | gpio_extcon_work(&extcon_data->work.work); | |
131 | ||
132 | return 0; | |
133 | ||
01eaf245 | 134 | err: |
be48308a | 135 | extcon_dev_unregister(&extcon_data->edev); |
be48308a MH |
136 | |
137 | return ret; | |
138 | } | |
139 | ||
93ed0327 | 140 | static int gpio_extcon_remove(struct platform_device *pdev) |
be48308a MH |
141 | { |
142 | struct gpio_extcon_data *extcon_data = platform_get_drvdata(pdev); | |
143 | ||
144 | cancel_delayed_work_sync(&extcon_data->work); | |
b945f3fa | 145 | free_irq(extcon_data->irq, extcon_data); |
be48308a | 146 | extcon_dev_unregister(&extcon_data->edev); |
be48308a MH |
147 | |
148 | return 0; | |
149 | } | |
150 | ||
2878bda8 | 151 | static struct platform_driver gpio_extcon_driver = { |
be48308a | 152 | .probe = gpio_extcon_probe, |
5f7e2228 | 153 | .remove = gpio_extcon_remove, |
be48308a MH |
154 | .driver = { |
155 | .name = "extcon-gpio", | |
156 | .owner = THIS_MODULE, | |
157 | }, | |
158 | }; | |
159 | ||
2878bda8 | 160 | module_platform_driver(gpio_extcon_driver); |
be48308a MH |
161 | |
162 | MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>"); | |
163 | MODULE_DESCRIPTION("GPIO extcon driver"); | |
164 | MODULE_LICENSE("GPL"); |