1 /*
2  * Driver for keys on GPIO lines capable of generating interrupts.
3  *
4  * Copyright 2005 Phil Blundell
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  */
10 
11 #include <linux/module.h>
12 
13 #include <linux/init.h>
14 #include <linux/fs.h>
15 #include <linux/interrupt.h>
16 #include <linux/irq.h>
17 #include <linux/sched.h>
18 #include <linux/pm.h>
19 #include <linux/sysctl.h>
20 #include <linux/proc_fs.h>
21 #include <linux/delay.h>
22 #include <linux/platform_device.h>
23 #include <linux/input.h>
24 #include <linux/gpio_keys.h>
25 
26 #include <asm/gpio.h>
27 
28 struct gpio_button_data {
29 	struct gpio_keys_button *button;
30 	struct input_dev *input;
31 	struct timer_list timer;
32 };
33 
34 struct gpio_keys_drvdata {
35 	struct input_dev *input;
36 	struct gpio_button_data data[0];
37 };
38 
39 static void gpio_keys_report_event(struct gpio_button_data *bdata)
40 {
41 	struct gpio_keys_button *button = bdata->button;
42 	struct input_dev *input = bdata->input;
43 	unsigned int type = button->type ?: EV_KEY;
44 	int state = (gpio_get_value(button->gpio) ? 1 : 0) ^ button->active_low;
45 
46 	input_event(input, type, button->code, !!state);
47 	input_sync(input);
48 }
49 
50 static void gpio_check_button(unsigned long _data)
51 {
52 	struct gpio_button_data *data = (struct gpio_button_data *)_data;
53 
54 	gpio_keys_report_event(data);
55 }
56 
57 static irqreturn_t gpio_keys_isr(int irq, void *dev_id)
58 {
59 	struct gpio_button_data *bdata = dev_id;
60 	struct gpio_keys_button *button = bdata->button;
61 
62 	BUG_ON(irq != gpio_to_irq(button->gpio));
63 
64 	if (button->debounce_interval)
65 		mod_timer(&bdata->timer,
66 			jiffies + msecs_to_jiffies(button->debounce_interval));
67 	else
68 		gpio_keys_report_event(bdata);
69 
70 	return IRQ_HANDLED;
71 }
72 
73 static int __devinit gpio_keys_probe(struct platform_device *pdev)
74 {
75 	struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
76 	struct gpio_keys_drvdata *ddata;
77 	struct input_dev *input;
78 	int i, error;
79 	int wakeup = 0;
80 
81 	ddata = kzalloc(sizeof(struct gpio_keys_drvdata) +
82 			pdata->nbuttons * sizeof(struct gpio_button_data),
83 			GFP_KERNEL);
84 	input = input_allocate_device();
85 	if (!ddata || !input) {
86 		error = -ENOMEM;
87 		goto fail1;
88 	}
89 
90 	platform_set_drvdata(pdev, ddata);
91 
92 	input->name = pdev->name;
93 	input->phys = "gpio-keys/input0";
94 	input->dev.parent = &pdev->dev;
95 
96 	input->id.bustype = BUS_HOST;
97 	input->id.vendor = 0x0001;
98 	input->id.product = 0x0001;
99 	input->id.version = 0x0100;
100 
101 	ddata->input = input;
102 
103 	for (i = 0; i < pdata->nbuttons; i++) {
104 		struct gpio_keys_button *button = &pdata->buttons[i];
105 		struct gpio_button_data *bdata = &ddata->data[i];
106 		int irq;
107 		unsigned int type = button->type ?: EV_KEY;
108 
109 		bdata->input = input;
110 		bdata->button = button;
111 		setup_timer(&bdata->timer,
112 			    gpio_check_button, (unsigned long)bdata);
113 
114 		error = gpio_request(button->gpio, button->desc ?: "gpio_keys");
115 		if (error < 0) {
116 			pr_err("gpio-keys: failed to request GPIO %d,"
117 				" error %d\n", button->gpio, error);
118 			goto fail2;
119 		}
120 
121 		error = gpio_direction_input(button->gpio);
122 		if (error < 0) {
123 			pr_err("gpio-keys: failed to configure input"
124 				" direction for GPIO %d, error %d\n",
125 				button->gpio, error);
126 			gpio_free(button->gpio);
127 			goto fail2;
128 		}
129 
130 		irq = gpio_to_irq(button->gpio);
131 		if (irq < 0) {
132 			error = irq;
133 			pr_err("gpio-keys: Unable to get irq number"
134 				" for GPIO %d, error %d\n",
135 				button->gpio, error);
136 			gpio_free(button->gpio);
137 			goto fail2;
138 		}
139 
140 		error = request_irq(irq, gpio_keys_isr,
141 				    IRQF_SAMPLE_RANDOM | IRQF_TRIGGER_RISING |
142 					IRQF_TRIGGER_FALLING,
143 				    button->desc ? button->desc : "gpio_keys",
144 				    bdata);
145 		if (error) {
146 			pr_err("gpio-keys: Unable to claim irq %d; error %d\n",
147 				irq, error);
148 			gpio_free(button->gpio);
149 			goto fail2;
150 		}
151 
152 		if (button->wakeup)
153 			wakeup = 1;
154 
155 		input_set_capability(input, type, button->code);
156 	}
157 
158 	error = input_register_device(input);
159 	if (error) {
160 		pr_err("gpio-keys: Unable to register input device, "
161 			"error: %d\n", error);
162 		goto fail2;
163 	}
164 
165 	device_init_wakeup(&pdev->dev, wakeup);
166 
167 	return 0;
168 
169  fail2:
170 	while (--i >= 0) {
171 		free_irq(gpio_to_irq(pdata->buttons[i].gpio), &ddata->data[i]);
172 		if (pdata->buttons[i].debounce_interval)
173 			del_timer_sync(&ddata->data[i].timer);
174 		gpio_free(pdata->buttons[i].gpio);
175 	}
176 
177 	platform_set_drvdata(pdev, NULL);
178  fail1:
179 	input_free_device(input);
180 	kfree(ddata);
181 
182 	return error;
183 }
184 
185 static int __devexit gpio_keys_remove(struct platform_device *pdev)
186 {
187 	struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
188 	struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev);
189 	struct input_dev *input = ddata->input;
190 	int i;
191 
192 	device_init_wakeup(&pdev->dev, 0);
193 
194 	for (i = 0; i < pdata->nbuttons; i++) {
195 		int irq = gpio_to_irq(pdata->buttons[i].gpio);
196 		free_irq(irq, &ddata->data[i]);
197 		if (pdata->buttons[i].debounce_interval)
198 			del_timer_sync(&ddata->data[i].timer);
199 		gpio_free(pdata->buttons[i].gpio);
200 	}
201 
202 	input_unregister_device(input);
203 
204 	return 0;
205 }
206 
207 
208 #ifdef CONFIG_PM
209 static int gpio_keys_suspend(struct platform_device *pdev, pm_message_t state)
210 {
211 	struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
212 	int i;
213 
214 	if (device_may_wakeup(&pdev->dev)) {
215 		for (i = 0; i < pdata->nbuttons; i++) {
216 			struct gpio_keys_button *button = &pdata->buttons[i];
217 			if (button->wakeup) {
218 				int irq = gpio_to_irq(button->gpio);
219 				enable_irq_wake(irq);
220 			}
221 		}
222 	}
223 
224 	return 0;
225 }
226 
227 static int gpio_keys_resume(struct platform_device *pdev)
228 {
229 	struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
230 	int i;
231 
232 	if (device_may_wakeup(&pdev->dev)) {
233 		for (i = 0; i < pdata->nbuttons; i++) {
234 			struct gpio_keys_button *button = &pdata->buttons[i];
235 			if (button->wakeup) {
236 				int irq = gpio_to_irq(button->gpio);
237 				disable_irq_wake(irq);
238 			}
239 		}
240 	}
241 
242 	return 0;
243 }
244 #else
245 #define gpio_keys_suspend	NULL
246 #define gpio_keys_resume	NULL
247 #endif
248 
249 static struct platform_driver gpio_keys_device_driver = {
250 	.probe		= gpio_keys_probe,
251 	.remove		= __devexit_p(gpio_keys_remove),
252 	.suspend	= gpio_keys_suspend,
253 	.resume		= gpio_keys_resume,
254 	.driver		= {
255 		.name	= "gpio-keys",
256 		.owner	= THIS_MODULE,
257 	}
258 };
259 
260 static int __init gpio_keys_init(void)
261 {
262 	return platform_driver_register(&gpio_keys_device_driver);
263 }
264 
265 static void __exit gpio_keys_exit(void)
266 {
267 	platform_driver_unregister(&gpio_keys_device_driver);
268 }
269 
270 module_init(gpio_keys_init);
271 module_exit(gpio_keys_exit);
272 
273 MODULE_LICENSE("GPL");
274 MODULE_AUTHOR("Phil Blundell <pb@handhelds.org>");
275 MODULE_DESCRIPTION("Keyboard driver for CPU GPIOs");
276 MODULE_ALIAS("platform:gpio-keys");
277