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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khadas_mcu_fan.c (3645B)

      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 * Khadas MCU Controlled FAN driver
      4 *
      5 * Copyright (C) 2020 BayLibre SAS
      6 * Author(s): Neil Armstrong <narmstrong@baylibre.com>
      7 */
      8
      9#include <linux/module.h>
     10#include <linux/of.h>
     11#include <linux/platform_device.h>
     12#include <linux/mfd/khadas-mcu.h>
     13#include <linux/regmap.h>
     14#include <linux/sysfs.h>
     15#include <linux/thermal.h>
     16
     17#define MAX_LEVEL 3
     18
     19struct khadas_mcu_fan_ctx {
     20	struct khadas_mcu *mcu;
     21	unsigned int level;
     22	struct thermal_cooling_device *cdev;
     23};
     24
     25static int khadas_mcu_fan_set_level(struct khadas_mcu_fan_ctx *ctx,
     26				    unsigned int level)
     27{
     28	int ret;
     29
     30	ret = regmap_write(ctx->mcu->regmap, KHADAS_MCU_CMD_FAN_STATUS_CTRL_REG,
     31			   level);
     32	if (ret)
     33		return ret;
     34
     35	ctx->level = level;
     36
     37	return 0;
     38}
     39
     40static int khadas_mcu_fan_get_max_state(struct thermal_cooling_device *cdev,
     41					unsigned long *state)
     42{
     43	*state = MAX_LEVEL;
     44
     45	return 0;
     46}
     47
     48static int khadas_mcu_fan_get_cur_state(struct thermal_cooling_device *cdev,
     49					unsigned long *state)
     50{
     51	struct khadas_mcu_fan_ctx *ctx = cdev->devdata;
     52
     53	*state = ctx->level;
     54
     55	return 0;
     56}
     57
     58static int
     59khadas_mcu_fan_set_cur_state(struct thermal_cooling_device *cdev,
     60			     unsigned long state)
     61{
     62	struct khadas_mcu_fan_ctx *ctx = cdev->devdata;
     63
     64	if (state > MAX_LEVEL)
     65		return -EINVAL;
     66
     67	if (state == ctx->level)
     68		return 0;
     69
     70	return khadas_mcu_fan_set_level(ctx, state);
     71}
     72
     73static const struct thermal_cooling_device_ops khadas_mcu_fan_cooling_ops = {
     74	.get_max_state = khadas_mcu_fan_get_max_state,
     75	.get_cur_state = khadas_mcu_fan_get_cur_state,
     76	.set_cur_state = khadas_mcu_fan_set_cur_state,
     77};
     78
     79static int khadas_mcu_fan_probe(struct platform_device *pdev)
     80{
     81	struct khadas_mcu *mcu = dev_get_drvdata(pdev->dev.parent);
     82	struct thermal_cooling_device *cdev;
     83	struct device *dev = &pdev->dev;
     84	struct khadas_mcu_fan_ctx *ctx;
     85	int ret;
     86
     87	ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
     88	if (!ctx)
     89		return -ENOMEM;
     90	ctx->mcu = mcu;
     91	platform_set_drvdata(pdev, ctx);
     92
     93	cdev = devm_thermal_of_cooling_device_register(dev->parent,
     94			dev->parent->of_node, "khadas-mcu-fan", ctx,
     95			&khadas_mcu_fan_cooling_ops);
     96	if (IS_ERR(cdev)) {
     97		ret = PTR_ERR(cdev);
     98		dev_err(dev, "Failed to register khadas-mcu-fan as cooling device: %d\n",
     99			ret);
    100		return ret;
    101	}
    102	ctx->cdev = cdev;
    103
    104	return 0;
    105}
    106
    107static void khadas_mcu_fan_shutdown(struct platform_device *pdev)
    108{
    109	struct khadas_mcu_fan_ctx *ctx = platform_get_drvdata(pdev);
    110
    111	khadas_mcu_fan_set_level(ctx, 0);
    112}
    113
    114#ifdef CONFIG_PM_SLEEP
    115static int khadas_mcu_fan_suspend(struct device *dev)
    116{
    117	struct khadas_mcu_fan_ctx *ctx = dev_get_drvdata(dev);
    118	unsigned int level_save = ctx->level;
    119	int ret;
    120
    121	ret = khadas_mcu_fan_set_level(ctx, 0);
    122	if (ret)
    123		return ret;
    124
    125	ctx->level = level_save;
    126
    127	return 0;
    128}
    129
    130static int khadas_mcu_fan_resume(struct device *dev)
    131{
    132	struct khadas_mcu_fan_ctx *ctx = dev_get_drvdata(dev);
    133
    134	return khadas_mcu_fan_set_level(ctx, ctx->level);
    135}
    136#endif
    137
    138static SIMPLE_DEV_PM_OPS(khadas_mcu_fan_pm, khadas_mcu_fan_suspend,
    139			 khadas_mcu_fan_resume);
    140
    141static const struct platform_device_id khadas_mcu_fan_id_table[] = {
    142	{ .name = "khadas-mcu-fan-ctrl", },
    143	{},
    144};
    145MODULE_DEVICE_TABLE(platform, khadas_mcu_fan_id_table);
    146
    147static struct platform_driver khadas_mcu_fan_driver = {
    148	.probe		= khadas_mcu_fan_probe,
    149	.shutdown	= khadas_mcu_fan_shutdown,
    150	.driver	= {
    151		.name		= "khadas-mcu-fan-ctrl",
    152		.pm		= &khadas_mcu_fan_pm,
    153	},
    154	.id_table	= khadas_mcu_fan_id_table,
    155};
    156
    157module_platform_driver(khadas_mcu_fan_driver);
    158
    159MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
    160MODULE_DESCRIPTION("Khadas MCU FAN driver");
    161MODULE_LICENSE("GPL");