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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 <[email protected]>
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/platform_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 * const 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<[email protected]>");
134MODULE_DESCRIPTION("Synaptics AS370 SoC hardware monitor");
135MODULE_LICENSE("GPL v2");