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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stm32-lptimer-trigger.c (2757B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * STM32 Low-Power Timer Trigger driver
      4 *
      5 * Copyright (C) STMicroelectronics 2017
      6 *
      7 * Author: Fabrice Gasnier <fabrice.gasnier@st.com>.
      8 *
      9 * Inspired by Benjamin Gaignard's stm32-timer-trigger driver
     10 */
     11
     12#include <linux/iio/timer/stm32-lptim-trigger.h>
     13#include <linux/mfd/stm32-lptimer.h>
     14#include <linux/module.h>
     15#include <linux/platform_device.h>
     16
     17/* List Low-Power Timer triggers */
     18static const char * const stm32_lptim_triggers[] = {
     19	LPTIM1_OUT,
     20	LPTIM2_OUT,
     21	LPTIM3_OUT,
     22};
     23
     24struct stm32_lptim_trigger {
     25	struct device *dev;
     26	const char *trg;
     27};
     28
     29static int stm32_lptim_validate_device(struct iio_trigger *trig,
     30				       struct iio_dev *indio_dev)
     31{
     32	if (indio_dev->modes & INDIO_HARDWARE_TRIGGERED)
     33		return 0;
     34
     35	return -EINVAL;
     36}
     37
     38static const struct iio_trigger_ops stm32_lptim_trigger_ops = {
     39	.validate_device = stm32_lptim_validate_device,
     40};
     41
     42/**
     43 * is_stm32_lptim_trigger
     44 * @trig: trigger to be checked
     45 *
     46 * return true if the trigger is a valid STM32 IIO Low-Power Timer Trigger
     47 * either return false
     48 */
     49bool is_stm32_lptim_trigger(struct iio_trigger *trig)
     50{
     51	return (trig->ops == &stm32_lptim_trigger_ops);
     52}
     53EXPORT_SYMBOL(is_stm32_lptim_trigger);
     54
     55static int stm32_lptim_setup_trig(struct stm32_lptim_trigger *priv)
     56{
     57	struct iio_trigger *trig;
     58
     59	trig = devm_iio_trigger_alloc(priv->dev, "%s", priv->trg);
     60	if  (!trig)
     61		return -ENOMEM;
     62
     63	trig->dev.parent = priv->dev->parent;
     64	trig->ops = &stm32_lptim_trigger_ops;
     65	iio_trigger_set_drvdata(trig, priv);
     66
     67	return devm_iio_trigger_register(priv->dev, trig);
     68}
     69
     70static int stm32_lptim_trigger_probe(struct platform_device *pdev)
     71{
     72	struct stm32_lptim_trigger *priv;
     73	u32 index;
     74	int ret;
     75
     76	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
     77	if (!priv)
     78		return -ENOMEM;
     79
     80	if (of_property_read_u32(pdev->dev.of_node, "reg", &index))
     81		return -EINVAL;
     82
     83	if (index >= ARRAY_SIZE(stm32_lptim_triggers))
     84		return -EINVAL;
     85
     86	priv->dev = &pdev->dev;
     87	priv->trg = stm32_lptim_triggers[index];
     88
     89	ret = stm32_lptim_setup_trig(priv);
     90	if (ret)
     91		return ret;
     92
     93	platform_set_drvdata(pdev, priv);
     94
     95	return 0;
     96}
     97
     98static const struct of_device_id stm32_lptim_trig_of_match[] = {
     99	{ .compatible = "st,stm32-lptimer-trigger", },
    100	{},
    101};
    102MODULE_DEVICE_TABLE(of, stm32_lptim_trig_of_match);
    103
    104static struct platform_driver stm32_lptim_trigger_driver = {
    105	.probe = stm32_lptim_trigger_probe,
    106	.driver = {
    107		.name = "stm32-lptimer-trigger",
    108		.of_match_table = stm32_lptim_trig_of_match,
    109	},
    110};
    111module_platform_driver(stm32_lptim_trigger_driver);
    112
    113MODULE_AUTHOR("Fabrice Gasnier <fabrice.gasnier@st.com>");
    114MODULE_ALIAS("platform:stm32-lptimer-trigger");
    115MODULE_DESCRIPTION("STMicroelectronics STM32 LPTIM trigger driver");
    116MODULE_LICENSE("GPL v2");