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 #include <linux/version.h>
13 
14 #include <linux/init.h>
15 #include <linux/fs.h>
16 #include <linux/interrupt.h>
17 #include <linux/irq.h>
18 #include <linux/sched.h>
19 #include <linux/pm.h>
20 #include <linux/sysctl.h>
21 #include <linux/proc_fs.h>
22 #include <linux/delay.h>
23 #include <linux/platform_device.h>
24 #include <linux/input.h>
25 #include <linux/gpio_keys.h>
26 
27 #include <asm/gpio.h>
28 
29 static irqreturn_t gpio_keys_isr(int irq, void *dev_id)
30 {
31 	int i;
32 	struct platform_device *pdev = dev_id;
33 	struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
34 	struct input_dev *input = platform_get_drvdata(pdev);
35 
36 	for (i = 0; i < pdata->nbuttons; i++) {
37 		struct gpio_keys_button *button = &pdata->buttons[i];
38 		int gpio = button->gpio;
39 
40 		if (irq == gpio_to_irq(gpio)) {
41 			unsigned int type = button->type ?: EV_KEY;
42 			int state = (gpio_get_value(gpio) ? 1 : 0) ^ button->active_low;
43 
44 			input_event(input, type, button->code, !!state);
45 			input_sync(input);
46 			return IRQ_HANDLED;
47 		}
48 	}
49 
50 	return IRQ_NONE;
51 }
52 
53 static int __devinit gpio_keys_probe(struct platform_device *pdev)
54 {
55 	struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
56 	struct input_dev *input;
57 	int i, error;
58 	int wakeup = 0;
59 
60 	input = input_allocate_device();
61 	if (!input)
62 		return -ENOMEM;
63 
64 	platform_set_drvdata(pdev, input);
65 
66 	input->evbit[0] = BIT_MASK(EV_KEY);
67 
68 	input->name = pdev->name;
69 	input->phys = "gpio-keys/input0";
70 	input->dev.parent = &pdev->dev;
71 
72 	input->id.bustype = BUS_HOST;
73 	input->id.vendor = 0x0001;
74 	input->id.product = 0x0001;
75 	input->id.version = 0x0100;
76 
77 	for (i = 0; i < pdata->nbuttons; i++) {
78 		struct gpio_keys_button *button = &pdata->buttons[i];
79 		int irq;
80 		unsigned int type = button->type ?: EV_KEY;
81 
82 		error = gpio_request(button->gpio, button->desc ?: "gpio_keys");
83 		if (error < 0) {
84 			pr_err("gpio-keys: failed to request GPIO %d,"
85 				" error %d\n", button->gpio, error);
86 			goto fail;
87 		}
88 
89 		error = gpio_direction_input(button->gpio);
90 		if (error < 0) {
91 			pr_err("gpio-keys: failed to configure input"
92 				" direction for GPIO %d, error %d\n",
93 				button->gpio, error);
94 			gpio_free(button->gpio);
95 			goto fail;
96 		}
97 
98 		irq = gpio_to_irq(button->gpio);
99 		if (irq < 0) {
100 			error = irq;
101 			pr_err("gpio-keys: Unable to get irq number"
102 				" for GPIO %d, error %d\n",
103 				button->gpio, error);
104 			gpio_free(button->gpio);
105 			goto fail;
106 		}
107 
108 		error = request_irq(irq, gpio_keys_isr,
109 				    IRQF_SAMPLE_RANDOM | IRQF_TRIGGER_RISING |
110 					IRQF_TRIGGER_FALLING,
111 				    button->desc ? button->desc : "gpio_keys",
112 				    pdev);
113 		if (error) {
114 			pr_err("gpio-keys: Unable to claim irq %d; error %d\n",
115 				irq, error);
116 			gpio_free(button->gpio);
117 			goto fail;
118 		}
119 
120 		if (button->wakeup)
121 			wakeup = 1;
122 
123 		input_set_capability(input, type, button->code);
124 	}
125 
126 	error = input_register_device(input);
127 	if (error) {
128 		pr_err("gpio-keys: Unable to register input device, "
129 			"error: %d\n", error);
130 		goto fail;
131 	}
132 
133 	device_init_wakeup(&pdev->dev, wakeup);
134 
135 	return 0;
136 
137  fail:
138 	while (--i >= 0) {
139 		free_irq(gpio_to_irq(pdata->buttons[i].gpio), pdev);
140 		gpio_free(pdata->buttons[i].gpio);
141 	}
142 
143 	platform_set_drvdata(pdev, NULL);
144 	input_free_device(input);
145 
146 	return error;
147 }
148 
149 static int __devexit gpio_keys_remove(struct platform_device *pdev)
150 {
151 	struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
152 	struct input_dev *input = platform_get_drvdata(pdev);
153 	int i;
154 
155 	device_init_wakeup(&pdev->dev, 0);
156 
157 	for (i = 0; i < pdata->nbuttons; i++) {
158 		int irq = gpio_to_irq(pdata->buttons[i].gpio);
159 		free_irq(irq, pdev);
160 		gpio_free(pdata->buttons[i].gpio);
161 	}
162 
163 	input_unregister_device(input);
164 
165 	return 0;
166 }
167 
168 
169 #ifdef CONFIG_PM
170 static int gpio_keys_suspend(struct platform_device *pdev, pm_message_t state)
171 {
172 	struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
173 	int i;
174 
175 	if (device_may_wakeup(&pdev->dev)) {
176 		for (i = 0; i < pdata->nbuttons; i++) {
177 			struct gpio_keys_button *button = &pdata->buttons[i];
178 			if (button->wakeup) {
179 				int irq = gpio_to_irq(button->gpio);
180 				enable_irq_wake(irq);
181 			}
182 		}
183 	}
184 
185 	return 0;
186 }
187 
188 static int gpio_keys_resume(struct platform_device *pdev)
189 {
190 	struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
191 	int i;
192 
193 	if (device_may_wakeup(&pdev->dev)) {
194 		for (i = 0; i < pdata->nbuttons; i++) {
195 			struct gpio_keys_button *button = &pdata->buttons[i];
196 			if (button->wakeup) {
197 				int irq = gpio_to_irq(button->gpio);
198 				disable_irq_wake(irq);
199 			}
200 		}
201 	}
202 
203 	return 0;
204 }
205 #else
206 #define gpio_keys_suspend	NULL
207 #define gpio_keys_resume	NULL
208 #endif
209 
210 struct platform_driver gpio_keys_device_driver = {
211 	.probe		= gpio_keys_probe,
212 	.remove		= __devexit_p(gpio_keys_remove),
213 	.suspend	= gpio_keys_suspend,
214 	.resume		= gpio_keys_resume,
215 	.driver		= {
216 		.name	= "gpio-keys",
217 		.owner	= THIS_MODULE,
218 	}
219 };
220 
221 static int __init gpio_keys_init(void)
222 {
223 	return platform_driver_register(&gpio_keys_device_driver);
224 }
225 
226 static void __exit gpio_keys_exit(void)
227 {
228 	platform_driver_unregister(&gpio_keys_device_driver);
229 }
230 
231 module_init(gpio_keys_init);
232 module_exit(gpio_keys_exit);
233 
234 MODULE_LICENSE("GPL");
235 MODULE_AUTHOR("Phil Blundell <pb@handhelds.org>");
236 MODULE_DESCRIPTION("Keyboard driver for CPU GPIOs");
237 MODULE_ALIAS("platform:gpio-keys");
238