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 | |
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 | |
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 |
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 | |
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, size: sizeof(*hwmon), GFP_KERNEL); |
102 | if (!hwmon) |
103 | return -ENOMEM; |
104 | |
105 | hwmon->base = devm_platform_ioremap_resource(pdev, index: 0); |
106 | if (IS_ERR(ptr: hwmon->base)) |
107 | return PTR_ERR(ptr: hwmon->base); |
108 | |
109 | init_pvt(hwmon); |
110 | |
111 | hwmon_dev = devm_hwmon_device_register_with_info(dev, |
112 | name: "as370" , |
113 | drvdata: hwmon, |
114 | info: &as370_chip_info, |
115 | NULL); |
116 | return PTR_ERR_OR_ZERO(ptr: 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 | |