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 	/* Enable auto repeat feature of Linux input subsystem */
102 	if (pdata->rep)
103 		__set_bit(EV_REP, input->evbit);
104 
105 	ddata->input = input;
106 
107 	for (i = 0; i < pdata->nbuttons; i++) {
108 		struct gpio_keys_button *button = &pdata->buttons[i];
109 		struct gpio_button_data *bdata = &ddata->data[i];
110 		int irq;
111 		unsigned int type = button->type ?: EV_KEY;
112 
113 		bdata->input = input;
114 		bdata->button = button;
115 		setup_timer(&bdata->timer,
116 			    gpio_check_button, (unsigned long)bdata);
117 
118 		error = gpio_request(button->gpio, button->desc ?: "gpio_keys");
119 		if (error < 0) {
120 			pr_err("gpio-keys: failed to request GPIO %d,"
121 				" error %d\n", button->gpio, error);
122 			goto fail2;
123 		}
124 
125 		error = gpio_direction_input(button->gpio);
126 		if (error < 0) {
127 			pr_err("gpio-keys: failed to configure input"
128 				" direction for GPIO %d, error %d\n",
129 				button->gpio, error);
130 			gpio_free(button->gpio);
131 			goto fail2;
132 		}
133 
134 		irq = gpio_to_irq(button->gpio);
135 		if (irq < 0) {
136 			error = irq;
137 			pr_err("gpio-keys: Unable to get irq number"
138 				" for GPIO %d, error %d\n",
139 				button->gpio, error);
140 			gpio_free(button->gpio);
141 			goto fail2;
142 		}
143 
144 		error = request_irq(irq, gpio_keys_isr,
145 				    IRQF_SAMPLE_RANDOM | IRQF_TRIGGER_RISING |
146 					IRQF_TRIGGER_FALLING,
147 				    button->desc ? button->desc : "gpio_keys",
148 				    bdata);
149 		if (error) {
150 			pr_err("gpio-keys: Unable to claim irq %d; error %d\n",
151 				irq, error);
152 			gpio_free(button->gpio);
153 			goto fail2;
154 		}
155 
156 		if (button->wakeup)
157 			wakeup = 1;
158 
159 		input_set_capability(input, type, button->code);
160 	}
161 
162 	error = input_register_device(input);
163 	if (error) {
164 		pr_err("gpio-keys: Unable to register input device, "
165 			"error: %d\n", error);
166 		goto fail2;
167 	}
168 
169 	device_init_wakeup(&pdev->dev, wakeup);
170 
171 	return 0;
172 
173  fail2:
174 	while (--i >= 0) {
175 		free_irq(gpio_to_irq(pdata->buttons[i].gpio), &ddata->data[i]);
176 		if (pdata->buttons[i].debounce_interval)
177 			del_timer_sync(&ddata->data[i].timer);
178 		gpio_free(pdata->buttons[i].gpio);
179 	}
180 
181 	platform_set_drvdata(pdev, NULL);
182  fail1:
183 	input_free_device(input);
184 	kfree(ddata);
185 
186 	return error;
187 }
188 
189 static int __devexit gpio_keys_remove(struct platform_device *pdev)
190 {
191 	struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
192 	struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev);
193 	struct input_dev *input = ddata->input;
194 	int i;
195 
196 	device_init_wakeup(&pdev->dev, 0);
197 
198 	for (i = 0; i < pdata->nbuttons; i++) {
199 		int irq = gpio_to_irq(pdata->buttons[i].gpio);
200 		free_irq(irq, &ddata->data[i]);
201 		if (pdata->buttons[i].debounce_interval)
202 			del_timer_sync(&ddata->data[i].timer);
203 		gpio_free(pdata->buttons[i].gpio);
204 	}
205 
206 	input_unregister_device(input);
207 
208 	return 0;
209 }
210 
211 
212 #ifdef CONFIG_PM
213 static int gpio_keys_suspend(struct platform_device *pdev, pm_message_t state)
214 {
215 	struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
216 	int i;
217 
218 	if (device_may_wakeup(&pdev->dev)) {
219 		for (i = 0; i < pdata->nbuttons; i++) {
220 			struct gpio_keys_button *button = &pdata->buttons[i];
221 			if (button->wakeup) {
222 				int irq = gpio_to_irq(button->gpio);
223 				enable_irq_wake(irq);
224 			}
225 		}
226 	}
227 
228 	return 0;
229 }
230 
231 static int gpio_keys_resume(struct platform_device *pdev)
232 {
233 	struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
234 	int i;
235 
236 	if (device_may_wakeup(&pdev->dev)) {
237 		for (i = 0; i < pdata->nbuttons; i++) {
238 			struct gpio_keys_button *button = &pdata->buttons[i];
239 			if (button->wakeup) {
240 				int irq = gpio_to_irq(button->gpio);
241 				disable_irq_wake(irq);
242 			}
243 		}
244 	}
245 
246 	return 0;
247 }
248 #else
249 #define gpio_keys_suspend	NULL
250 #define gpio_keys_resume	NULL
251 #endif
252 
253 static struct platform_driver gpio_keys_device_driver = {
254 	.probe		= gpio_keys_probe,
255 	.remove		= __devexit_p(gpio_keys_remove),
256 	.suspend	= gpio_keys_suspend,
257 	.resume		= gpio_keys_resume,
258 	.driver		= {
259 		.name	= "gpio-keys",
260 		.owner	= THIS_MODULE,
261 	}
262 };
263 
264 static int __init gpio_keys_init(void)
265 {
266 	return platform_driver_register(&gpio_keys_device_driver);
267 }
268 
269 static void __exit gpio_keys_exit(void)
270 {
271 	platform_driver_unregister(&gpio_keys_device_driver);
272 }
273 
274 module_init(gpio_keys_init);
275 module_exit(gpio_keys_exit);
276 
277 MODULE_LICENSE("GPL");
278 MODULE_AUTHOR("Phil Blundell <pb@handhelds.org>");
279 MODULE_DESCRIPTION("Keyboard driver for CPU GPIOs");
280 MODULE_ALIAS("platform:gpio-keys");
281