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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gpio-vibra.c (4967B)


      1// SPDX-License-Identifier: GPL-2.0+
      2/*
      3 *  GPIO vibrator driver
      4 *
      5 *  Copyright (C) 2019 Luca Weiss <luca@z3ntu.xyz>
      6 *
      7 *  Based on PWM vibrator driver:
      8 *  Copyright (C) 2017 Collabora Ltd.
      9 *
     10 *  Based on previous work from:
     11 *  Copyright (C) 2012 Dmitry Torokhov <dmitry.torokhov@gmail.com>
     12 *
     13 *  Based on PWM beeper driver:
     14 *  Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
     15 */
     16
     17#include <linux/gpio/consumer.h>
     18#include <linux/input.h>
     19#include <linux/kernel.h>
     20#include <linux/module.h>
     21#include <linux/of_device.h>
     22#include <linux/platform_device.h>
     23#include <linux/property.h>
     24#include <linux/regulator/consumer.h>
     25#include <linux/slab.h>
     26
     27struct gpio_vibrator {
     28	struct input_dev *input;
     29	struct gpio_desc *gpio;
     30	struct regulator *vcc;
     31
     32	struct work_struct play_work;
     33	bool running;
     34	bool vcc_on;
     35};
     36
     37static int gpio_vibrator_start(struct gpio_vibrator *vibrator)
     38{
     39	struct device *pdev = vibrator->input->dev.parent;
     40	int err;
     41
     42	if (!vibrator->vcc_on) {
     43		err = regulator_enable(vibrator->vcc);
     44		if (err) {
     45			dev_err(pdev, "failed to enable regulator: %d\n", err);
     46			return err;
     47		}
     48		vibrator->vcc_on = true;
     49	}
     50
     51	gpiod_set_value_cansleep(vibrator->gpio, 1);
     52
     53	return 0;
     54}
     55
     56static void gpio_vibrator_stop(struct gpio_vibrator *vibrator)
     57{
     58	gpiod_set_value_cansleep(vibrator->gpio, 0);
     59
     60	if (vibrator->vcc_on) {
     61		regulator_disable(vibrator->vcc);
     62		vibrator->vcc_on = false;
     63	}
     64}
     65
     66static void gpio_vibrator_play_work(struct work_struct *work)
     67{
     68	struct gpio_vibrator *vibrator =
     69		container_of(work, struct gpio_vibrator, play_work);
     70
     71	if (vibrator->running)
     72		gpio_vibrator_start(vibrator);
     73	else
     74		gpio_vibrator_stop(vibrator);
     75}
     76
     77static int gpio_vibrator_play_effect(struct input_dev *dev, void *data,
     78				     struct ff_effect *effect)
     79{
     80	struct gpio_vibrator *vibrator = input_get_drvdata(dev);
     81	int level;
     82
     83	level = effect->u.rumble.strong_magnitude;
     84	if (!level)
     85		level = effect->u.rumble.weak_magnitude;
     86
     87	vibrator->running = level;
     88	schedule_work(&vibrator->play_work);
     89
     90	return 0;
     91}
     92
     93static void gpio_vibrator_close(struct input_dev *input)
     94{
     95	struct gpio_vibrator *vibrator = input_get_drvdata(input);
     96
     97	cancel_work_sync(&vibrator->play_work);
     98	gpio_vibrator_stop(vibrator);
     99	vibrator->running = false;
    100}
    101
    102static int gpio_vibrator_probe(struct platform_device *pdev)
    103{
    104	struct gpio_vibrator *vibrator;
    105	int err;
    106
    107	vibrator = devm_kzalloc(&pdev->dev, sizeof(*vibrator), GFP_KERNEL);
    108	if (!vibrator)
    109		return -ENOMEM;
    110
    111	vibrator->input = devm_input_allocate_device(&pdev->dev);
    112	if (!vibrator->input)
    113		return -ENOMEM;
    114
    115	vibrator->vcc = devm_regulator_get(&pdev->dev, "vcc");
    116	err = PTR_ERR_OR_ZERO(vibrator->vcc);
    117	if (err) {
    118		if (err != -EPROBE_DEFER)
    119			dev_err(&pdev->dev, "Failed to request regulator: %d\n",
    120				err);
    121		return err;
    122	}
    123
    124	vibrator->gpio = devm_gpiod_get(&pdev->dev, "enable", GPIOD_OUT_LOW);
    125	err = PTR_ERR_OR_ZERO(vibrator->gpio);
    126	if (err) {
    127		if (err != -EPROBE_DEFER)
    128			dev_err(&pdev->dev, "Failed to request main gpio: %d\n",
    129				err);
    130		return err;
    131	}
    132
    133	INIT_WORK(&vibrator->play_work, gpio_vibrator_play_work);
    134
    135	vibrator->input->name = "gpio-vibrator";
    136	vibrator->input->id.bustype = BUS_HOST;
    137	vibrator->input->close = gpio_vibrator_close;
    138
    139	input_set_drvdata(vibrator->input, vibrator);
    140	input_set_capability(vibrator->input, EV_FF, FF_RUMBLE);
    141
    142	err = input_ff_create_memless(vibrator->input, NULL,
    143				      gpio_vibrator_play_effect);
    144	if (err) {
    145		dev_err(&pdev->dev, "Couldn't create FF dev: %d\n", err);
    146		return err;
    147	}
    148
    149	err = input_register_device(vibrator->input);
    150	if (err) {
    151		dev_err(&pdev->dev, "Couldn't register input dev: %d\n", err);
    152		return err;
    153	}
    154
    155	platform_set_drvdata(pdev, vibrator);
    156
    157	return 0;
    158}
    159
    160static int __maybe_unused gpio_vibrator_suspend(struct device *dev)
    161{
    162	struct platform_device *pdev = to_platform_device(dev);
    163	struct gpio_vibrator *vibrator = platform_get_drvdata(pdev);
    164
    165	cancel_work_sync(&vibrator->play_work);
    166	if (vibrator->running)
    167		gpio_vibrator_stop(vibrator);
    168
    169	return 0;
    170}
    171
    172static int __maybe_unused gpio_vibrator_resume(struct device *dev)
    173{
    174	struct platform_device *pdev = to_platform_device(dev);
    175	struct gpio_vibrator *vibrator = platform_get_drvdata(pdev);
    176
    177	if (vibrator->running)
    178		gpio_vibrator_start(vibrator);
    179
    180	return 0;
    181}
    182
    183static SIMPLE_DEV_PM_OPS(gpio_vibrator_pm_ops,
    184			 gpio_vibrator_suspend, gpio_vibrator_resume);
    185
    186#ifdef CONFIG_OF
    187static const struct of_device_id gpio_vibra_dt_match_table[] = {
    188	{ .compatible = "gpio-vibrator" },
    189	{}
    190};
    191MODULE_DEVICE_TABLE(of, gpio_vibra_dt_match_table);
    192#endif
    193
    194static struct platform_driver gpio_vibrator_driver = {
    195	.probe	= gpio_vibrator_probe,
    196	.driver	= {
    197		.name	= "gpio-vibrator",
    198		.pm	= &gpio_vibrator_pm_ops,
    199		.of_match_table = of_match_ptr(gpio_vibra_dt_match_table),
    200	},
    201};
    202module_platform_driver(gpio_vibrator_driver);
    203
    204MODULE_AUTHOR("Luca Weiss <luca@z3ntu.xy>");
    205MODULE_DESCRIPTION("GPIO vibrator driver");
    206MODULE_LICENSE("GPL");
    207MODULE_ALIAS("platform:gpio-vibrator");