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 u32 as370_hwmon_temp_config[] = {
80	HWMON_T_INPUT,
81	0
82};
83
84static const struct hwmon_channel_info as370_hwmon_temp = {
85	.type = hwmon_temp,
86	.config = as370_hwmon_temp_config,
87};
88
89static const struct hwmon_channel_info *as370_hwmon_info[] = {
90	&as370_hwmon_temp,
91	NULL
92};
93
94static const struct hwmon_ops as370_hwmon_ops = {
95	.is_visible = as370_hwmon_is_visible,
96	.read = as370_hwmon_read,
97};
98
99static const struct hwmon_chip_info as370_chip_info = {
100	.ops = &as370_hwmon_ops,
101	.info = as370_hwmon_info,
102};
103
104static int as370_hwmon_probe(struct platform_device *pdev)
105{
106	struct device *hwmon_dev;
107	struct as370_hwmon *hwmon;
108	struct device *dev = &pdev->dev;
109
110	hwmon = devm_kzalloc(dev, sizeof(*hwmon), GFP_KERNEL);
111	if (!hwmon)
112		return -ENOMEM;
113
114	hwmon->base = devm_platform_ioremap_resource(pdev, 0);
115	if (IS_ERR(hwmon->base))
116		return PTR_ERR(hwmon->base);
117
118	init_pvt(hwmon);
119
120	hwmon_dev = devm_hwmon_device_register_with_info(dev,
121							 "as370",
122							 hwmon,
123							 &as370_chip_info,
124							 NULL);
125	return PTR_ERR_OR_ZERO(hwmon_dev);
126}
127
128static const struct of_device_id as370_hwmon_match[] = {
129	{ .compatible = "syna,as370-hwmon" },
130	{},
131};
132MODULE_DEVICE_TABLE(of, as370_hwmon_match);
133
134static struct platform_driver as370_hwmon_driver = {
135	.probe = as370_hwmon_probe,
136	.driver = {
137		.name = "as370-hwmon",
138		.of_match_table = as370_hwmon_match,
139	},
140};
141module_platform_driver(as370_hwmon_driver);
142
143MODULE_AUTHOR("Jisheng Zhang<jszhang@kernel.org>");
144MODULE_DESCRIPTION("Synaptics AS370 SoC hardware monitor");
145MODULE_LICENSE("GPL v2");
146