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/mod_devicetable.h>
15 #include <linux/platform_device.h>
16
17 #define CTRL 0x0
18 #define PD BIT(0)
19 #define EN BIT(1)
20 #define T_SEL BIT(2)
21 #define V_SEL BIT(3)
22 #define NMOS_SEL BIT(8)
23 #define PMOS_SEL BIT(9)
24 #define STS 0x4
25 #define BN_MASK GENMASK(11, 0)
26 #define EOC BIT(12)
27
28 struct as370_hwmon {
29 void __iomem *base;
30 };
31
init_pvt(struct as370_hwmon * hwmon)32 static void init_pvt(struct as370_hwmon *hwmon)
33 {
34 u32 val;
35 void __iomem *addr = hwmon->base + CTRL;
36
37 val = PD;
38 writel_relaxed(val, addr);
39 val |= T_SEL;
40 writel_relaxed(val, addr);
41 val |= EN;
42 writel_relaxed(val, addr);
43 val &= ~PD;
44 writel_relaxed(val, addr);
45 }
46
as370_hwmon_read(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long * temp)47 static int as370_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
48 u32 attr, int channel, long *temp)
49 {
50 int val;
51 struct as370_hwmon *hwmon = dev_get_drvdata(dev);
52
53 switch (attr) {
54 case hwmon_temp_input:
55 val = readl_relaxed(hwmon->base + STS) & BN_MASK;
56 *temp = DIV_ROUND_CLOSEST(val * 251802, 4096) - 85525;
57 break;
58 default:
59 return -EOPNOTSUPP;
60 }
61
62 return 0;
63 }
64
65 static umode_t
as370_hwmon_is_visible(const void * data,enum hwmon_sensor_types type,u32 attr,int channel)66 as370_hwmon_is_visible(const void *data, enum hwmon_sensor_types type,
67 u32 attr, int channel)
68 {
69 if (type != hwmon_temp)
70 return 0;
71
72 switch (attr) {
73 case hwmon_temp_input:
74 return 0444;
75 default:
76 return 0;
77 }
78 }
79
80 static const struct hwmon_channel_info * const as370_hwmon_info[] = {
81 HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT),
82 NULL
83 };
84
85 static const struct hwmon_ops as370_hwmon_ops = {
86 .is_visible = as370_hwmon_is_visible,
87 .read = as370_hwmon_read,
88 };
89
90 static const struct hwmon_chip_info as370_chip_info = {
91 .ops = &as370_hwmon_ops,
92 .info = as370_hwmon_info,
93 };
94
as370_hwmon_probe(struct platform_device * pdev)95 static int as370_hwmon_probe(struct platform_device *pdev)
96 {
97 struct device *hwmon_dev;
98 struct as370_hwmon *hwmon;
99 struct device *dev = &pdev->dev;
100
101 hwmon = devm_kzalloc(dev, sizeof(*hwmon), GFP_KERNEL);
102 if (!hwmon)
103 return -ENOMEM;
104
105 hwmon->base = devm_platform_ioremap_resource(pdev, 0);
106 if (IS_ERR(hwmon->base))
107 return PTR_ERR(hwmon->base);
108
109 init_pvt(hwmon);
110
111 hwmon_dev = devm_hwmon_device_register_with_info(dev,
112 "as370",
113 hwmon,
114 &as370_chip_info,
115 NULL);
116 return PTR_ERR_OR_ZERO(hwmon_dev);
117 }
118
119 static const struct of_device_id as370_hwmon_match[] = {
120 { .compatible = "syna,as370-hwmon" },
121 {},
122 };
123 MODULE_DEVICE_TABLE(of, as370_hwmon_match);
124
125 static struct platform_driver as370_hwmon_driver = {
126 .probe = as370_hwmon_probe,
127 .driver = {
128 .name = "as370-hwmon",
129 .of_match_table = as370_hwmon_match,
130 },
131 };
132 module_platform_driver(as370_hwmon_driver);
133
134 MODULE_AUTHOR("Jisheng Zhang<jszhang@kernel.org>");
135 MODULE_DESCRIPTION("Synaptics AS370 SoC hardware monitor");
136 MODULE_LICENSE("GPL v2");
137