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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mtk.c (3118B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * Mediatek GNSS receiver driver
      4 *
      5 * Copyright (C) 2018 Johan Hovold <johan@kernel.org>
      6 */
      7
      8#include <linux/errno.h>
      9#include <linux/gnss.h>
     10#include <linux/init.h>
     11#include <linux/kernel.h>
     12#include <linux/module.h>
     13#include <linux/of.h>
     14#include <linux/regulator/consumer.h>
     15#include <linux/serdev.h>
     16
     17#include "serial.h"
     18
     19struct mtk_data {
     20	struct regulator *vbackup;
     21	struct regulator *vcc;
     22};
     23
     24static int mtk_set_active(struct gnss_serial *gserial)
     25{
     26	struct mtk_data *data = gnss_serial_get_drvdata(gserial);
     27	int ret;
     28
     29	ret = regulator_enable(data->vcc);
     30	if (ret)
     31		return ret;
     32
     33	return 0;
     34}
     35
     36static int mtk_set_standby(struct gnss_serial *gserial)
     37{
     38	struct mtk_data *data = gnss_serial_get_drvdata(gserial);
     39	int ret;
     40
     41	ret = regulator_disable(data->vcc);
     42	if (ret)
     43		return ret;
     44
     45	return 0;
     46}
     47
     48static int mtk_set_power(struct gnss_serial *gserial,
     49			 enum gnss_serial_pm_state state)
     50{
     51	switch (state) {
     52	case GNSS_SERIAL_ACTIVE:
     53		return mtk_set_active(gserial);
     54	case GNSS_SERIAL_OFF:
     55	case GNSS_SERIAL_STANDBY:
     56		return mtk_set_standby(gserial);
     57	}
     58
     59	return -EINVAL;
     60}
     61
     62static const struct gnss_serial_ops mtk_gserial_ops = {
     63	.set_power = mtk_set_power,
     64};
     65
     66static int mtk_probe(struct serdev_device *serdev)
     67{
     68	struct gnss_serial *gserial;
     69	struct mtk_data *data;
     70	int ret;
     71
     72	gserial = gnss_serial_allocate(serdev, sizeof(*data));
     73	if (IS_ERR(gserial)) {
     74		ret = PTR_ERR(gserial);
     75		return ret;
     76	}
     77
     78	gserial->ops = &mtk_gserial_ops;
     79
     80	gserial->gdev->type = GNSS_TYPE_MTK;
     81
     82	data = gnss_serial_get_drvdata(gserial);
     83
     84	data->vcc = devm_regulator_get(&serdev->dev, "vcc");
     85	if (IS_ERR(data->vcc)) {
     86		ret = PTR_ERR(data->vcc);
     87		goto err_free_gserial;
     88	}
     89
     90	data->vbackup = devm_regulator_get_optional(&serdev->dev, "vbackup");
     91	if (IS_ERR(data->vbackup)) {
     92		ret = PTR_ERR(data->vbackup);
     93		if (ret == -ENODEV)
     94			data->vbackup = NULL;
     95		else
     96			goto err_free_gserial;
     97	}
     98
     99	if (data->vbackup) {
    100		ret = regulator_enable(data->vbackup);
    101		if (ret)
    102			goto err_free_gserial;
    103	}
    104
    105	ret = gnss_serial_register(gserial);
    106	if (ret)
    107		goto err_disable_vbackup;
    108
    109	return 0;
    110
    111err_disable_vbackup:
    112	if (data->vbackup)
    113		regulator_disable(data->vbackup);
    114err_free_gserial:
    115	gnss_serial_free(gserial);
    116
    117	return ret;
    118}
    119
    120static void mtk_remove(struct serdev_device *serdev)
    121{
    122	struct gnss_serial *gserial = serdev_device_get_drvdata(serdev);
    123	struct mtk_data *data = gnss_serial_get_drvdata(gserial);
    124
    125	gnss_serial_deregister(gserial);
    126	if (data->vbackup)
    127		regulator_disable(data->vbackup);
    128	gnss_serial_free(gserial);
    129}
    130
    131#ifdef CONFIG_OF
    132static const struct of_device_id mtk_of_match[] = {
    133	{ .compatible = "globaltop,pa6h" },
    134	{},
    135};
    136MODULE_DEVICE_TABLE(of, mtk_of_match);
    137#endif
    138
    139static struct serdev_device_driver mtk_driver = {
    140	.driver	= {
    141		.name		= "gnss-mtk",
    142		.of_match_table	= of_match_ptr(mtk_of_match),
    143		.pm		= &gnss_serial_pm_ops,
    144	},
    145	.probe	= mtk_probe,
    146	.remove	= mtk_remove,
    147};
    148module_serdev_device_driver(mtk_driver);
    149
    150MODULE_AUTHOR("Loys Ollivier <lollivier@baylibre.com>");
    151MODULE_DESCRIPTION("Mediatek GNSS receiver driver");
    152MODULE_LICENSE("GPL v2");