aboutsummaryrefslogtreecommitdiff
path: root/drivers/hwmon/as370-hwmon.c
blob: 63b5b2d6e593072c69ccbe18e537bb69a9e1f5f2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
// 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");