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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> | |
29 | #include <linux/extcon.h> | |
30 | #include <linux/workqueue.h> | |
31 | #include <linux/gpio.h> | |
32 | #include <linux/extcon.h> | |
33 | #include <linux/extcon/extcon_gpio.h> | |
34 | ||
35 | struct gpio_extcon_data { | |
36 | struct extcon_dev edev; | |
37 | unsigned gpio; | |
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); | |
53 | extcon_set_state(&data->edev, state); | |
54 | } | |
55 | ||
56 | static irqreturn_t gpio_irq_handler(int irq, void *dev_id) | |
57 | { | |
58 | struct gpio_extcon_data *extcon_data = dev_id; | |
59 | ||
60 | schedule_delayed_work(&extcon_data->work, | |
61 | extcon_data->debounce_jiffies); | |
62 | return IRQ_HANDLED; | |
63 | } | |
64 | ||
65 | static ssize_t extcon_gpio_print_state(struct extcon_dev *edev, char *buf) | |
66 | { | |
67 | struct gpio_extcon_data *extcon_data = | |
68 | container_of(edev, struct gpio_extcon_data, edev); | |
69 | const char *state; | |
70 | if (extcon_get_state(edev)) | |
71 | state = extcon_data->state_on; | |
72 | else | |
73 | state = extcon_data->state_off; | |
74 | ||
75 | if (state) | |
76 | return sprintf(buf, "%s\n", state); | |
77 | return -EINVAL; | |
78 | } | |
79 | ||
80 | static int __devinit gpio_extcon_probe(struct platform_device *pdev) | |
81 | { | |
82 | struct gpio_extcon_platform_data *pdata = pdev->dev.platform_data; | |
83 | struct gpio_extcon_data *extcon_data; | |
84 | int ret = 0; | |
85 | ||
86 | if (!pdata) | |
87 | return -EBUSY; | |
88 | if (!pdata->irq_flags) { | |
89 | dev_err(&pdev->dev, "IRQ flag is not specified.\n"); | |
90 | return -EINVAL; | |
91 | } | |
92 | ||
93 | extcon_data = devm_kzalloc(&pdev->dev, sizeof(struct gpio_extcon_data), | |
94 | GFP_KERNEL); | |
95 | if (!extcon_data) | |
96 | return -ENOMEM; | |
97 | ||
98 | extcon_data->edev.name = pdata->name; | |
99 | extcon_data->gpio = pdata->gpio; | |
100 | extcon_data->state_on = pdata->state_on; | |
101 | extcon_data->state_off = pdata->state_off; | |
102 | if (pdata->state_on && pdata->state_off) | |
103 | extcon_data->edev.print_state = extcon_gpio_print_state; | |
104 | extcon_data->debounce_jiffies = msecs_to_jiffies(pdata->debounce); | |
105 | ||
106 | ret = extcon_dev_register(&extcon_data->edev, &pdev->dev); | |
107 | if (ret < 0) | |
108 | goto err_extcon_dev_register; | |
109 | ||
110 | ret = gpio_request_one(extcon_data->gpio, GPIOF_DIR_IN, pdev->name); | |
111 | if (ret < 0) | |
112 | goto err_request_gpio; | |
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; | |
119 | goto err_detect_irq_num_failed; | |
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) | |
126 | goto err_request_irq; | |
127 | ||
3f1dc550 | 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 | ||
134 | err_request_irq: | |
135 | err_detect_irq_num_failed: | |
136 | gpio_free(extcon_data->gpio); | |
137 | err_request_gpio: | |
138 | extcon_dev_unregister(&extcon_data->edev); | |
139 | err_extcon_dev_register: | |
140 | devm_kfree(&pdev->dev, extcon_data); | |
141 | ||
142 | return ret; | |
143 | } | |
144 | ||
145 | static int __devexit gpio_extcon_remove(struct platform_device *pdev) | |
146 | { | |
147 | struct gpio_extcon_data *extcon_data = platform_get_drvdata(pdev); | |
148 | ||
149 | cancel_delayed_work_sync(&extcon_data->work); | |
3f1dc550 | 150 | free_irq(extcon_data->irq, extcon_data); |
be48308a MH |
151 | gpio_free(extcon_data->gpio); |
152 | extcon_dev_unregister(&extcon_data->edev); | |
153 | devm_kfree(&pdev->dev, extcon_data); | |
154 | ||
155 | return 0; | |
156 | } | |
157 | ||
2878bda8 | 158 | static struct platform_driver gpio_extcon_driver = { |
be48308a MH |
159 | .probe = gpio_extcon_probe, |
160 | .remove = __devexit_p(gpio_extcon_remove), | |
161 | .driver = { | |
162 | .name = "extcon-gpio", | |
163 | .owner = THIS_MODULE, | |
164 | }, | |
165 | }; | |
166 | ||
2878bda8 | 167 | module_platform_driver(gpio_extcon_driver); |
be48308a MH |
168 | |
169 | MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>"); | |
170 | MODULE_DESCRIPTION("GPIO extcon driver"); | |
171 | MODULE_LICENSE("GPL"); |