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/drivers/input/misc/sgi_btns.c

http://github.com/mirrors/linux
C | 131 lines | 98 code | 27 blank | 6 comment | 11 complexity | 7b97566e480437aa2cfeb7e5415bdf70 MD5 | raw file
  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 *  SGI Volume Button interface driver
  4 *
  5 *  Copyright (C) 2008  Thomas Bogendoerfer <tsbogend@alpha.franken.de>
  6 */
  7#include <linux/input.h>
  8#include <linux/ioport.h>
  9#include <linux/module.h>
 10#include <linux/platform_device.h>
 11#include <linux/slab.h>
 12
 13#ifdef CONFIG_SGI_IP22
 14#include <asm/sgi/ioc.h>
 15
 16static inline u8 button_status(void)
 17{
 18	u8 status;
 19
 20	status = readb(&sgioc->panel) ^ 0xa0;
 21	return ((status & 0x80) >> 6) | ((status & 0x20) >> 5);
 22}
 23#endif
 24
 25#ifdef CONFIG_SGI_IP32
 26#include <asm/ip32/mace.h>
 27
 28static inline u8 button_status(void)
 29{
 30	u64 status;
 31
 32	status = readq(&mace->perif.audio.control);
 33	writeq(status & ~(3U << 23), &mace->perif.audio.control);
 34
 35	return (status >> 23) & 3;
 36}
 37#endif
 38
 39#define BUTTONS_POLL_INTERVAL	30	/* msec */
 40#define BUTTONS_COUNT_THRESHOLD	3
 41
 42static const unsigned short sgi_map[] = {
 43	KEY_VOLUMEDOWN,
 44	KEY_VOLUMEUP
 45};
 46
 47struct buttons_dev {
 48	unsigned short keymap[ARRAY_SIZE(sgi_map)];
 49	int count[ARRAY_SIZE(sgi_map)];
 50};
 51
 52static void handle_buttons(struct input_dev *input)
 53{
 54	struct buttons_dev *bdev = input_get_drvdata(input);
 55	u8 status;
 56	int i;
 57
 58	status = button_status();
 59
 60	for (i = 0; i < ARRAY_SIZE(bdev->keymap); i++) {
 61		if (status & (1U << i)) {
 62			if (++bdev->count[i] == BUTTONS_COUNT_THRESHOLD) {
 63				input_event(input, EV_MSC, MSC_SCAN, i);
 64				input_report_key(input, bdev->keymap[i], 1);
 65				input_sync(input);
 66			}
 67		} else {
 68			if (bdev->count[i] >= BUTTONS_COUNT_THRESHOLD) {
 69				input_event(input, EV_MSC, MSC_SCAN, i);
 70				input_report_key(input, bdev->keymap[i], 0);
 71				input_sync(input);
 72			}
 73			bdev->count[i] = 0;
 74		}
 75	}
 76}
 77
 78static int sgi_buttons_probe(struct platform_device *pdev)
 79{
 80	struct buttons_dev *bdev;
 81	struct input_dev *input;
 82	int error, i;
 83
 84	bdev = devm_kzalloc(&pdev->dev, sizeof(*bdev), GFP_KERNEL);
 85	if (!bdev)
 86		return -ENOMEM;
 87
 88	input = devm_input_allocate_device(&pdev->dev);
 89	if (!input)
 90		return -ENOMEM;
 91
 92	memcpy(bdev->keymap, sgi_map, sizeof(bdev->keymap));
 93
 94	input_set_drvdata(input, bdev);
 95
 96	input->name = "SGI buttons";
 97	input->phys = "sgi/input0";
 98	input->id.bustype = BUS_HOST;
 99
100	input->keycode = bdev->keymap;
101	input->keycodemax = ARRAY_SIZE(bdev->keymap);
102	input->keycodesize = sizeof(unsigned short);
103
104	input_set_capability(input, EV_MSC, MSC_SCAN);
105	__set_bit(EV_KEY, input->evbit);
106	for (i = 0; i < ARRAY_SIZE(sgi_map); i++)
107		__set_bit(bdev->keymap[i], input->keybit);
108	__clear_bit(KEY_RESERVED, input->keybit);
109
110	error = input_setup_polling(input, handle_buttons);
111	if (error)
112		return error;
113
114	input_set_poll_interval(input, BUTTONS_POLL_INTERVAL);
115
116	error = input_register_device(input);
117	if (error)
118		return error;
119
120	return 0;
121}
122
123static struct platform_driver sgi_buttons_driver = {
124	.probe	= sgi_buttons_probe,
125	.driver	= {
126		.name	= "sgibtns",
127	},
128};
129module_platform_driver(sgi_buttons_driver);
130
131MODULE_LICENSE("GPL");