cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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sensehat-joystick.c (3826B)

      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 * Raspberry Pi Sense HAT joystick driver
      4 * http://raspberrypi.org
      5 *
      6 * Copyright (C) 2015 Raspberry Pi
      7 * Copyright (C) 2021 Charles Mirabile, Mwesigwa Guma, Joel Savitz
      8 *
      9 * Original Author: Serge Schneider
     10 * Revised for upstream Linux by: Charles Mirabile, Mwesigwa Guma, Joel Savitz
     11 */
     12
     13#include <linux/module.h>
     14#include <linux/input.h>
     15#include <linux/i2c.h>
     16#include <linux/interrupt.h>
     17#include <linux/platform_device.h>
     18#include <linux/regmap.h>
     19#include <linux/property.h>
     20
     21#define JOYSTICK_SMB_REG 0xf2
     22
     23struct sensehat_joystick {
     24	struct platform_device *pdev;
     25	struct input_dev *keys_dev;
     26	unsigned long prev_states;
     27	struct regmap *regmap;
     28};
     29
     30static const unsigned int keymap[] = {
     31	BTN_DPAD_DOWN, BTN_DPAD_RIGHT, BTN_DPAD_UP, BTN_SELECT, BTN_DPAD_LEFT,
     32};
     33
     34static irqreturn_t sensehat_joystick_report(int irq, void *cookie)
     35{
     36	struct sensehat_joystick *sensehat_joystick = cookie;
     37	unsigned long curr_states, changes;
     38	unsigned int keys;
     39	int error;
     40	int i;
     41
     42	error = regmap_read(sensehat_joystick->regmap, JOYSTICK_SMB_REG, &keys);
     43	if (error < 0) {
     44		dev_err(&sensehat_joystick->pdev->dev,
     45			"Failed to read joystick state: %d", error);
     46		return IRQ_NONE;
     47	}
     48	curr_states = keys;
     49	bitmap_xor(&changes, &curr_states, &sensehat_joystick->prev_states,
     50		   ARRAY_SIZE(keymap));
     51
     52	for_each_set_bit(i, &changes, ARRAY_SIZE(keymap))
     53		input_report_key(sensehat_joystick->keys_dev, keymap[i],
     54				 curr_states & BIT(i));
     55
     56	input_sync(sensehat_joystick->keys_dev);
     57	sensehat_joystick->prev_states = keys;
     58	return IRQ_HANDLED;
     59}
     60
     61static int sensehat_joystick_probe(struct platform_device *pdev)
     62{
     63	struct sensehat_joystick *sensehat_joystick;
     64	int error, i, irq;
     65
     66	sensehat_joystick = devm_kzalloc(&pdev->dev, sizeof(*sensehat_joystick),
     67					 GFP_KERNEL);
     68	if (!sensehat_joystick)
     69		return -ENOMEM;
     70
     71	sensehat_joystick->pdev = pdev;
     72
     73	sensehat_joystick->regmap = dev_get_regmap(pdev->dev.parent, NULL);
     74	if (!sensehat_joystick->regmap) {
     75		dev_err(&pdev->dev, "unable to get sensehat regmap");
     76		return -ENODEV;
     77	}
     78
     79	sensehat_joystick->keys_dev = devm_input_allocate_device(&pdev->dev);
     80	if (!sensehat_joystick->keys_dev) {
     81		dev_err(&pdev->dev, "Could not allocate input device");
     82		return -ENOMEM;
     83	}
     84
     85	sensehat_joystick->keys_dev->name = "Raspberry Pi Sense HAT Joystick";
     86	sensehat_joystick->keys_dev->phys = "sensehat-joystick/input0";
     87	sensehat_joystick->keys_dev->id.bustype = BUS_I2C;
     88
     89	__set_bit(EV_KEY, sensehat_joystick->keys_dev->evbit);
     90	__set_bit(EV_REP, sensehat_joystick->keys_dev->evbit);
     91	for (i = 0; i < ARRAY_SIZE(keymap); i++)
     92		__set_bit(keymap[i], sensehat_joystick->keys_dev->keybit);
     93
     94	error = input_register_device(sensehat_joystick->keys_dev);
     95	if (error) {
     96		dev_err(&pdev->dev, "Could not register input device");
     97		return error;
     98	}
     99
    100	irq = platform_get_irq(pdev, 0);
    101	if (irq < 0) {
    102		dev_err(&pdev->dev, "Could not retrieve interrupt request");
    103		return irq;
    104	}
    105
    106	error = devm_request_threaded_irq(&pdev->dev, irq,
    107					  NULL, sensehat_joystick_report,
    108					  IRQF_ONESHOT, "keys",
    109					  sensehat_joystick);
    110	if (error) {
    111		dev_err(&pdev->dev, "IRQ request failed");
    112		return error;
    113	}
    114
    115	return 0;
    116}
    117
    118static const struct of_device_id sensehat_joystick_device_id[] = {
    119	{ .compatible = "raspberrypi,sensehat-joystick" },
    120	{},
    121};
    122MODULE_DEVICE_TABLE(of, sensehat_joystick_device_id);
    123
    124static struct platform_driver sensehat_joystick_driver = {
    125	.probe = sensehat_joystick_probe,
    126	.driver = {
    127		.name = "sensehat-joystick",
    128		.of_match_table = sensehat_joystick_device_id,
    129	},
    130};
    131
    132module_platform_driver(sensehat_joystick_driver);
    133
    134MODULE_DESCRIPTION("Raspberry Pi Sense HAT joystick driver");
    135MODULE_AUTHOR("Charles Mirabile <cmirabil@redhat.com>");
    136MODULE_AUTHOR("Serge Schneider <serge@raspberrypi.org>");
    137MODULE_LICENSE("GPL");