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 #include <linux/workqueue.h>
26 
27 #include <asm/gpio.h>
28 
29 struct gpio_button_data {
30 	struct gpio_keys_button *button;
31 	struct input_dev *input;
32 	struct timer_list timer;
33 	struct work_struct work;
34 };
35 
36 struct gpio_keys_drvdata {
37 	struct input_dev *input;
38 	struct gpio_button_data data[0];
39 };
40 
41 static void gpio_keys_report_event(struct work_struct *work)
42 {
43 	struct gpio_button_data *bdata =
44 		container_of(work, struct gpio_button_data, work);
45 	struct gpio_keys_button *button = bdata->button;
46 	struct input_dev *input = bdata->input;
47 	unsigned int type = button->type ?: EV_KEY;
48 	int state = (gpio_get_value(button->gpio) ? 1 : 0) ^ button->active_low;
49 
50 	input_event(input, type, button->code, !!state);
51 	input_sync(input);
52 }
53 
54 static void gpio_keys_timer(unsigned long _data)
55 {
56 	struct gpio_button_data *data = (struct gpio_button_data *)_data;
57 
58 	schedule_work(&data->work);
59 }
60 
61 static irqreturn_t gpio_keys_isr(int irq, void *dev_id)
62 {
63 	struct gpio_button_data *bdata = dev_id;
64 	struct gpio_keys_button *button = bdata->button;
65 
66 	BUG_ON(irq != gpio_to_irq(button->gpio));
67 
68 	if (button->debounce_interval)
69 		mod_timer(&bdata->timer,
70 			jiffies + msecs_to_jiffies(button->debounce_interval));
71 	else
72 		schedule_work(&bdata->work);
73 
74 	return IRQ_HANDLED;
75 }
76 
77 static int __devinit gpio_keys_probe(struct platform_device *pdev)
78 {
79 	struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
80 	struct gpio_keys_drvdata *ddata;
81 	struct input_dev *input;
82 	int i, error;
83 	int wakeup = 0;
84 
85 	ddata = kzalloc(sizeof(struct gpio_keys_drvdata) +
86 			pdata->nbuttons * sizeof(struct gpio_button_data),
87 			GFP_KERNEL);
88 	input = input_allocate_device();
89 	if (!ddata || !input) {
90 		error = -ENOMEM;
91 		goto fail1;
92 	}
93 
94 	platform_set_drvdata(pdev, ddata);
95 
96 	input->name = pdev->name;
97 	input->phys = "gpio-keys/input0";
98 	input->dev.parent = &pdev->dev;
99 
100 	input->id.bustype = BUS_HOST;
101 	input->id.vendor = 0x0001;
102 	input->id.product = 0x0001;
103 	input->id.version = 0x0100;
104 
105 	/* Enable auto repeat feature of Linux input subsystem */
106 	if (pdata->rep)
107 		__set_bit(EV_REP, input->evbit);
108 
109 	ddata->input = input;
110 
111 	for (i = 0; i < pdata->nbuttons; i++) {
112 		struct gpio_keys_button *button = &pdata->buttons[i];
113 		struct gpio_button_data *bdata = &ddata->data[i];
114 		int irq;
115 		unsigned int type = button->type ?: EV_KEY;
116 
117 		bdata->input = input;
118 		bdata->button = button;
119 		setup_timer(&bdata->timer,
120 			    gpio_keys_timer, (unsigned long)bdata);
121 		INIT_WORK(&bdata->work, gpio_keys_report_event);
122 
123 		error = gpio_request(button->gpio, button->desc ?: "gpio_keys");
124 		if (error < 0) {
125 			pr_err("gpio-keys: failed to request GPIO %d,"
126 				" error %d\n", button->gpio, error);
127 			goto fail2;
128 		}
129 
130 		error = gpio_direction_input(button->gpio);
131 		if (error < 0) {
132 			pr_err("gpio-keys: failed to configure input"
133 				" direction for GPIO %d, error %d\n",
134 				button->gpio, error);
135 			gpio_free(button->gpio);
136 			goto fail2;
137 		}
138 
139 		irq = gpio_to_irq(button->gpio);
140 		if (irq < 0) {
141 			error = irq;
142 			pr_err("gpio-keys: Unable to get irq number"
143 				" for GPIO %d, error %d\n",
144 				button->gpio, error);
145 			gpio_free(button->gpio);
146 			goto fail2;
147 		}
148 
149 		error = request_irq(irq, gpio_keys_isr,
150 				    IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
151 				    button->desc ? button->desc : "gpio_keys",
152 				    bdata);
153 		if (error) {
154 			pr_err("gpio-keys: Unable to claim irq %d; error %d\n",
155 				irq, error);
156 			gpio_free(button->gpio);
157 			goto fail2;
158 		}
159 
160 		if (button->wakeup)
161 			wakeup = 1;
162 
163 		input_set_capability(input, type, button->code);
164 	}
165 
166 	error = input_register_device(input);
167 	if (error) {
168 		pr_err("gpio-keys: Unable to register input device, "
169 			"error: %d\n", error);
170 		goto fail2;
171 	}
172 
173 	device_init_wakeup(&pdev->dev, wakeup);
174 
175 	return 0;
176 
177  fail2:
178 	while (--i >= 0) {
179 		free_irq(gpio_to_irq(pdata->buttons[i].gpio), &ddata->data[i]);
180 		if (pdata->buttons[i].debounce_interval)
181 			del_timer_sync(&ddata->data[i].timer);
182 		cancel_work_sync(&ddata->data[i].work);
183 		gpio_free(pdata->buttons[i].gpio);
184 	}
185 
186 	platform_set_drvdata(pdev, NULL);
187  fail1:
188 	input_free_device(input);
189 	kfree(ddata);
190 
191 	return error;
192 }
193 
194 static int __devexit gpio_keys_remove(struct platform_device *pdev)
195 {
196 	struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
197 	struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev);
198 	struct input_dev *input = ddata->input;
199 	int i;
200 
201 	device_init_wakeup(&pdev->dev, 0);
202 
203 	for (i = 0; i < pdata->nbuttons; i++) {
204 		int irq = gpio_to_irq(pdata->buttons[i].gpio);
205 		free_irq(irq, &ddata->data[i]);
206 		if (pdata->buttons[i].debounce_interval)
207 			del_timer_sync(&ddata->data[i].timer);
208 		cancel_work_sync(&ddata->data[i].work);
209 		gpio_free(pdata->buttons[i].gpio);
210 	}
211 
212 	input_unregister_device(input);
213 
214 	return 0;
215 }
216 
217 
218 #ifdef CONFIG_PM
219 static int gpio_keys_suspend(struct device *dev)
220 {
221 	struct platform_device *pdev = to_platform_device(dev);
222 	struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
223 	int i;
224 
225 	if (device_may_wakeup(&pdev->dev)) {
226 		for (i = 0; i < pdata->nbuttons; i++) {
227 			struct gpio_keys_button *button = &pdata->buttons[i];
228 			if (button->wakeup) {
229 				int irq = gpio_to_irq(button->gpio);
230 				enable_irq_wake(irq);
231 			}
232 		}
233 	}
234 
235 	return 0;
236 }
237 
238 static int gpio_keys_resume(struct device *dev)
239 {
240 	struct platform_device *pdev = to_platform_device(dev);
241 	struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
242 	int i;
243 
244 	if (device_may_wakeup(&pdev->dev)) {
245 		for (i = 0; i < pdata->nbuttons; i++) {
246 			struct gpio_keys_button *button = &pdata->buttons[i];
247 			if (button->wakeup) {
248 				int irq = gpio_to_irq(button->gpio);
249 				disable_irq_wake(irq);
250 			}
251 		}
252 	}
253 
254 	return 0;
255 }
256 
257 static const struct dev_pm_ops gpio_keys_pm_ops = {
258 	.suspend	= gpio_keys_suspend,
259 	.resume		= gpio_keys_resume,
260 };
261 #endif
262 
263 static struct platform_driver gpio_keys_device_driver = {
264 	.probe		= gpio_keys_probe,
265 	.remove		= __devexit_p(gpio_keys_remove),
266 	.driver		= {
267 		.name	= "gpio-keys",
268 		.owner	= THIS_MODULE,
269 #ifdef CONFIG_PM
270 		.pm	= &gpio_keys_pm_ops,
271 #endif
272 	}
273 };
274 
275 static int __init gpio_keys_init(void)
276 {
277 	return platform_driver_register(&gpio_keys_device_driver);
278 }
279 
280 static void __exit gpio_keys_exit(void)
281 {
282 	platform_driver_unregister(&gpio_keys_device_driver);
283 }
284 
285 module_init(gpio_keys_init);
286 module_exit(gpio_keys_exit);
287 
288 MODULE_LICENSE("GPL");
289 MODULE_AUTHOR("Phil Blundell <pb@handhelds.org>");
290 MODULE_DESCRIPTION("Keyboard driver for CPU GPIOs");
291 MODULE_ALIAS("platform:gpio-keys");
292