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
27 struct as370_hwmon {
28 void __iomem *base;
29 };
30
init_pvt(struct as370_hwmon * hwmon)31 static 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
as370_hwmon_read(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long * temp)46 static 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
64 static umode_t
as370_hwmon_is_visible(const void * data,enum hwmon_sensor_types type,u32 attr,int channel)65 as370_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
79 static const u32 as370_hwmon_temp_config[] = {
80 HWMON_T_INPUT,
81 0
82 };
83
84 static const struct hwmon_channel_info as370_hwmon_temp = {
85 .type = hwmon_temp,
86 .config = as370_hwmon_temp_config,
87 };
88
89 static const struct hwmon_channel_info *as370_hwmon_info[] = {
90 &as370_hwmon_temp,
91 NULL
92 };
93
94 static const struct hwmon_ops as370_hwmon_ops = {
95 .is_visible = as370_hwmon_is_visible,
96 .read = as370_hwmon_read,
97 };
98
99 static const struct hwmon_chip_info as370_chip_info = {
100 .ops = &as370_hwmon_ops,
101 .info = as370_hwmon_info,
102 };
103
as370_hwmon_probe(struct platform_device * pdev)104 static 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
128 static const struct of_device_id as370_hwmon_match[] = {
129 { .compatible = "syna,as370-hwmon" },
130 {},
131 };
132 MODULE_DEVICE_TABLE(of, as370_hwmon_match);
133
134 static 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 };
141 module_platform_driver(as370_hwmon_driver);
142
143 MODULE_AUTHOR("Jisheng Zhang<jszhang@kernel.org>");
144 MODULE_DESCRIPTION("Synaptics AS370 SoC hardware monitor");
145 MODULE_LICENSE("GPL v2");
146