linux-zen-server/drivers/hwmon/as370-hwmon.c

136 lines
2.8 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Synaptics AS370 SoC Hardware Monitoring Driver
*
* Copyright (C) 2018 Synaptics Incorporated
* Author: Jisheng Zhang <jszhang@kernel.org>
*/
#include <linux/bitops.h>
#include <linux/hwmon.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of_device.h>
#define CTRL 0x0
#define PD BIT(0)
#define EN BIT(1)
#define T_SEL BIT(2)
#define V_SEL BIT(3)
#define NMOS_SEL BIT(8)
#define PMOS_SEL BIT(9)
#define STS 0x4
#define BN_MASK GENMASK(11, 0)
#define EOC BIT(12)
struct as370_hwmon {
void __iomem *base;
};
static void init_pvt(struct as370_hwmon *hwmon)
{
u32 val;
void __iomem *addr = hwmon->base + CTRL;
val = PD;
writel_relaxed(val, addr);
val |= T_SEL;
writel_relaxed(val, addr);
val |= EN;
writel_relaxed(val, addr);
val &= ~PD;
writel_relaxed(val, addr);
}
static int as370_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
u32 attr, int channel, long *temp)
{
int val;
struct as370_hwmon *hwmon = dev_get_drvdata(dev);
switch (attr) {
case hwmon_temp_input:
val = readl_relaxed(hwmon->base + STS) & BN_MASK;
*temp = DIV_ROUND_CLOSEST(val * 251802, 4096) - 85525;
break;
default:
return -EOPNOTSUPP;
}
return 0;
}
static umode_t
as370_hwmon_is_visible(const void *data, enum hwmon_sensor_types type,
u32 attr, int channel)
{
if (type != hwmon_temp)
return 0;
switch (attr) {
case hwmon_temp_input:
return 0444;
default:
return 0;
}
}
static const struct hwmon_channel_info *as370_hwmon_info[] = {
HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT),
NULL
};
static const struct hwmon_ops as370_hwmon_ops = {
.is_visible = as370_hwmon_is_visible,
.read = as370_hwmon_read,
};
static const struct hwmon_chip_info as370_chip_info = {
.ops = &as370_hwmon_ops,
.info = as370_hwmon_info,
};
static int as370_hwmon_probe(struct platform_device *pdev)
{
struct device *hwmon_dev;
struct as370_hwmon *hwmon;
struct device *dev = &pdev->dev;
hwmon = devm_kzalloc(dev, sizeof(*hwmon), GFP_KERNEL);
if (!hwmon)
return -ENOMEM;
hwmon->base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(hwmon->base))
return PTR_ERR(hwmon->base);
init_pvt(hwmon);
hwmon_dev = devm_hwmon_device_register_with_info(dev,
"as370",
hwmon,
&as370_chip_info,
NULL);
return PTR_ERR_OR_ZERO(hwmon_dev);
}
static const struct of_device_id as370_hwmon_match[] = {
{ .compatible = "syna,as370-hwmon" },
{},
};
MODULE_DEVICE_TABLE(of, as370_hwmon_match);
static struct platform_driver as370_hwmon_driver = {
.probe = as370_hwmon_probe,
.driver = {
.name = "as370-hwmon",
.of_match_table = as370_hwmon_match,
},
};
module_platform_driver(as370_hwmon_driver);
MODULE_AUTHOR("Jisheng Zhang<jszhang@kernel.org>");
MODULE_DESCRIPTION("Synaptics AS370 SoC hardware monitor");
MODULE_LICENSE("GPL v2");