// SPDX-License-Identifier: GPL-2.0-or-later/* *  SGI Volume Button interface driver * *  Copyright (C) 2008  Thomas Bogendoerfer <tsbogend@alpha.franken.de> */#include <linux/input.h>#include <linux/ioport.h>#include <linux/module.h>#include <linux/platform_device.h>#include <linux/slab.h> #ifdef CONFIG_SGI_IP22#include <asm/sgi/ioc.h> static inline u8 button_status(void){	u8 status; 	status = readb(&sgioc->panel) ^ 0xa0;	return ((status & 0x80) >> 6) | ((status & 0x20) >> 5);}#endif #ifdef CONFIG_SGI_IP32#include <asm/ip32/mace.h> static inline u8 button_status(void){	u64 status; 	status = readq(&mace->perif.audio.control);	writeq(status & ~(3U << 23), &mace->perif.audio.control); 	return (status >> 23) & 3;}#endif #define BUTTONS_POLL_INTERVAL	30	/* msec */#define BUTTONS_COUNT_THRESHOLD	3 static const unsigned short sgi_map[] = {	KEY_VOLUMEDOWN,	KEY_VOLUMEUP}; struct buttons_dev {	unsigned short keymap[ARRAY_SIZE(sgi_map)];	int count[ARRAY_SIZE(sgi_map)];}; static void handle_buttons(struct input_dev *input){	struct buttons_dev *bdev = input_get_drvdata(input);	u8 status;	int i; 	status = button_status(); 	for (i = 0; i < ARRAY_SIZE(bdev->keymap); i++) {		if (status & (1U << i)) {			if (++bdev->count[i] == BUTTONS_COUNT_THRESHOLD) {				input_event(input, EV_MSC, MSC_SCAN, i);				input_report_key(input, bdev->keymap[i], 1);				input_sync(input);			}		} else {			if (bdev->count[i] >= BUTTONS_COUNT_THRESHOLD) {				input_event(input, EV_MSC, MSC_SCAN, i);				input_report_key(input, bdev->keymap[i], 0);				input_sync(input);			}			bdev->count[i] = 0;		}	}} static int sgi_buttons_probe(struct platform_device *pdev){	struct buttons_dev *bdev;	struct input_dev *input;	int error, i; 	bdev = devm_kzalloc(&pdev->dev, sizeof(*bdev), GFP_KERNEL);	if (!bdev)		return -ENOMEM; 	input = devm_input_allocate_device(&pdev->dev);	if (!input)		return -ENOMEM; 	memcpy(bdev->keymap, sgi_map, sizeof(bdev->keymap)); 	input_set_drvdata(input, bdev); 	input->name = "SGI buttons";	input->phys = "sgi/input0";	input->id.bustype = BUS_HOST; 	input->keycode = bdev->keymap;	input->keycodemax = ARRAY_SIZE(bdev->keymap);	input->keycodesize = sizeof(unsigned short); 	input_set_capability(input, EV_MSC, MSC_SCAN);	__set_bit(EV_KEY, input->evbit);	for (i = 0; i < ARRAY_SIZE(sgi_map); i++)		__set_bit(bdev->keymap[i], input->keybit);	__clear_bit(KEY_RESERVED, input->keybit); 	error = input_setup_polling(input, handle_buttons);	if (error)		return error; 	input_set_poll_interval(input, BUTTONS_POLL_INTERVAL); 	error = input_register_device(input);	if (error)		return error; 	return 0;} static struct platform_driver sgi_buttons_driver = {	.probe	= sgi_buttons_probe,	.driver	= {		.name	= "sgibtns",	},};module_platform_driver(sgi_buttons_driver); MODULE_LICENSE("GPL");