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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as370-hwmon.c (2902B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * Synaptics AS370 SoC Hardware Monitoring Driver
      4 *
      5 * Copyright (C) 2018 Synaptics Incorporated
      6 * Author: Jisheng Zhang <jszhang@kernel.org>
      7 */
      8
      9#include <linux/bitops.h>
     10#include <linux/hwmon.h>
     11#include <linux/init.h>
     12#include <linux/io.h>
     13#include <linux/module.h>
     14#include <linux/of_device.h>
     15
     16#define CTRL		0x0
     17#define  PD		BIT(0)
     18#define  EN		BIT(1)
     19#define  T_SEL		BIT(2)
     20#define  V_SEL		BIT(3)
     21#define  NMOS_SEL	BIT(8)
     22#define  PMOS_SEL	BIT(9)
     23#define STS		0x4
     24#define  BN_MASK	GENMASK(11, 0)
     25#define  EOC		BIT(12)
     26
     27struct as370_hwmon {
     28	void __iomem *base;
     29};
     30
     31static void init_pvt(struct as370_hwmon *hwmon)
     32{
     33	u32 val;
     34	void __iomem *addr = hwmon->base + CTRL;
     35
     36	val = PD;
     37	writel_relaxed(val, addr);
     38	val |= T_SEL;
     39	writel_relaxed(val, addr);
     40	val |= EN;
     41	writel_relaxed(val, addr);
     42	val &= ~PD;
     43	writel_relaxed(val, addr);
     44}
     45
     46static int as370_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
     47			    u32 attr, int channel, long *temp)
     48{
     49	int val;
     50	struct as370_hwmon *hwmon = dev_get_drvdata(dev);
     51
     52	switch (attr) {
     53	case hwmon_temp_input:
     54		val = readl_relaxed(hwmon->base + STS) & BN_MASK;
     55		*temp = DIV_ROUND_CLOSEST(val * 251802, 4096) - 85525;
     56		break;
     57	default:
     58		return -EOPNOTSUPP;
     59	}
     60
     61	return 0;
     62}
     63
     64static umode_t
     65as370_hwmon_is_visible(const void *data, enum hwmon_sensor_types type,
     66		       u32 attr, int channel)
     67{
     68	if (type != hwmon_temp)
     69		return 0;
     70
     71	switch (attr) {
     72	case hwmon_temp_input:
     73		return 0444;
     74	default:
     75		return 0;
     76	}
     77}
     78
     79static const struct hwmon_channel_info *as370_hwmon_info[] = {
     80	HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT),
     81	NULL
     82};
     83
     84static const struct hwmon_ops as370_hwmon_ops = {
     85	.is_visible = as370_hwmon_is_visible,
     86	.read = as370_hwmon_read,
     87};
     88
     89static const struct hwmon_chip_info as370_chip_info = {
     90	.ops = &as370_hwmon_ops,
     91	.info = as370_hwmon_info,
     92};
     93
     94static int as370_hwmon_probe(struct platform_device *pdev)
     95{
     96	struct device *hwmon_dev;
     97	struct as370_hwmon *hwmon;
     98	struct device *dev = &pdev->dev;
     99
    100	hwmon = devm_kzalloc(dev, sizeof(*hwmon), GFP_KERNEL);
    101	if (!hwmon)
    102		return -ENOMEM;
    103
    104	hwmon->base = devm_platform_ioremap_resource(pdev, 0);
    105	if (IS_ERR(hwmon->base))
    106		return PTR_ERR(hwmon->base);
    107
    108	init_pvt(hwmon);
    109
    110	hwmon_dev = devm_hwmon_device_register_with_info(dev,
    111							 "as370",
    112							 hwmon,
    113							 &as370_chip_info,
    114							 NULL);
    115	return PTR_ERR_OR_ZERO(hwmon_dev);
    116}
    117
    118static const struct of_device_id as370_hwmon_match[] = {
    119	{ .compatible = "syna,as370-hwmon" },
    120	{},
    121};
    122MODULE_DEVICE_TABLE(of, as370_hwmon_match);
    123
    124static struct platform_driver as370_hwmon_driver = {
    125	.probe = as370_hwmon_probe,
    126	.driver = {
    127		.name = "as370-hwmon",
    128		.of_match_table = as370_hwmon_match,
    129	},
    130};
    131module_platform_driver(as370_hwmon_driver);
    132
    133MODULE_AUTHOR("Jisheng Zhang<jszhang@kernel.org>");
    134MODULE_DESCRIPTION("Synaptics AS370 SoC hardware monitor");
    135MODULE_LICENSE("GPL v2");