/drivers/input/misc/gpio_output.c

 1/* drivers/input/misc/gpio_output.c
 2 *
 3 * Copyright (C) 2007 Google, Inc.
 4 *
 5 * This software is licensed under the terms of the GNU General Public
 6 * License version 2, as published by the Free Software Foundation, and
 7 * may be copied, distributed, and modified under those terms.
 8 *
 9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12 * GNU General Public License for more details.
13 *
14 */
15
16#include <linux/kernel.h>
17#include <linux/gpio.h>
18#include <linux/gpio_event.h>
19
20int gpio_event_output_event(
21	struct gpio_event_input_devs *input_devs, struct gpio_event_info *info,
22	void **data, unsigned int dev, unsigned int type,
23	unsigned int code, int value)
24{
25	int i;
26	struct gpio_event_output_info *oi;
27	oi = container_of(info, struct gpio_event_output_info, info);
28	if (type != oi->type)
29		return 0;
30	if (!(oi->flags & GPIOEDF_ACTIVE_HIGH))
31		value = !value;
32	for (i = 0; i < oi->keymap_size; i++)
33		if (dev == oi->keymap[i].dev && code == oi->keymap[i].code)
34			gpio_set_value(oi->keymap[i].gpio, value);
35	return 0;
36}
37
38int gpio_event_output_func(
39	struct gpio_event_input_devs *input_devs, struct gpio_event_info *info,
40	void **data, int func)
41{
42	int ret;
43	int i;
44	struct gpio_event_output_info *oi;
45	oi = container_of(info, struct gpio_event_output_info, info);
46
47	if (func == GPIO_EVENT_FUNC_SUSPEND || func == GPIO_EVENT_FUNC_RESUME)
48		return 0;
49
50	if (func == GPIO_EVENT_FUNC_INIT) {
51		int output_level = !(oi->flags & GPIOEDF_ACTIVE_HIGH);
52
53		for (i = 0; i < oi->keymap_size; i++) {
54			int dev = oi->keymap[i].dev;
55			if (dev >= input_devs->count) {
56				pr_err("gpio_event_output_func: bad device "
57					"index %d >= %d for key code %d\n",
58					dev, input_devs->count,
59					oi->keymap[i].code);
60				ret = -EINVAL;
61				goto err_bad_keymap;
62			}
63			input_set_capability(input_devs->dev[dev], oi->type,
64					     oi->keymap[i].code);
65		}
66
67		for (i = 0; i < oi->keymap_size; i++) {
68			ret = gpio_request(oi->keymap[i].gpio,
69					   "gpio_event_output");
70			if (ret) {
71				pr_err("gpio_event_output_func: gpio_request "
72					"failed for %d\n", oi->keymap[i].gpio);
73				goto err_gpio_request_failed;
74			}
75			ret = gpio_direction_output(oi->keymap[i].gpio,
76						    output_level);
77			if (ret) {
78				pr_err("gpio_event_output_func: "
79					"gpio_direction_output failed for %d\n",
80					oi->keymap[i].gpio);
81				goto err_gpio_direction_output_failed;
82			}
83		}
84		return 0;
85	}
86
87	ret = 0;
88	for (i = oi->keymap_size - 1; i >= 0; i--) {
89err_gpio_direction_output_failed:
90		gpio_free(oi->keymap[i].gpio);
91err_gpio_request_failed:
92		;
93	}
94err_bad_keymap:
95	return ret;
96}
97