1 | // SPDX-License-Identifier: GPL-2.0+ |
2 | /* |
3 | * Functions to access SY3686A power management chip temperature |
4 | * |
5 | * Copyright (C) 2021 reMarkable AS - http://www.remarkable.com/ |
6 | * |
7 | * Authors: Lars Ivar Miljeteig <lars.ivar.miljeteig@remarkable.com> |
8 | * Alistair Francis <alistair@alistair23.me> |
9 | */ |
10 | |
11 | #include <linux/err.h> |
12 | #include <linux/hwmon.h> |
13 | #include <linux/init.h> |
14 | #include <linux/module.h> |
15 | #include <linux/platform_device.h> |
16 | #include <linux/regmap.h> |
17 | #include <linux/regulator/machine.h> |
18 | |
19 | #include <linux/mfd/sy7636a.h> |
20 | |
21 | static int sy7636a_read(struct device *dev, enum hwmon_sensor_types type, |
22 | u32 attr, int channel, long *temp) |
23 | { |
24 | struct regmap *regmap = dev_get_drvdata(dev); |
25 | int ret, reg_val; |
26 | |
27 | ret = regmap_read(map: regmap, |
28 | SY7636A_REG_TERMISTOR_READOUT, val: ®_val); |
29 | if (ret) |
30 | return ret; |
31 | |
32 | *temp = reg_val * 1000; |
33 | |
34 | return 0; |
35 | } |
36 | |
37 | static umode_t sy7636a_is_visible(const void *data, |
38 | enum hwmon_sensor_types type, |
39 | u32 attr, int channel) |
40 | { |
41 | if (type != hwmon_temp) |
42 | return 0; |
43 | |
44 | if (attr != hwmon_temp_input) |
45 | return 0; |
46 | |
47 | return 0444; |
48 | } |
49 | |
50 | static const struct hwmon_ops sy7636a_hwmon_ops = { |
51 | .is_visible = sy7636a_is_visible, |
52 | .read = sy7636a_read, |
53 | }; |
54 | |
55 | static const struct hwmon_channel_info * const sy7636a_info[] = { |
56 | HWMON_CHANNEL_INFO(chip, HWMON_C_REGISTER_TZ), |
57 | HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT), |
58 | NULL |
59 | }; |
60 | |
61 | static const struct hwmon_chip_info sy7636a_chip_info = { |
62 | .ops = &sy7636a_hwmon_ops, |
63 | .info = sy7636a_info, |
64 | }; |
65 | |
66 | static int sy7636a_sensor_probe(struct platform_device *pdev) |
67 | { |
68 | struct regmap *regmap = dev_get_regmap(dev: pdev->dev.parent, NULL); |
69 | struct regulator *regulator; |
70 | struct device *hwmon_dev; |
71 | int err; |
72 | |
73 | if (!regmap) |
74 | return -EPROBE_DEFER; |
75 | |
76 | regulator = devm_regulator_get(dev: &pdev->dev, id: "vcom" ); |
77 | if (IS_ERR(ptr: regulator)) |
78 | return PTR_ERR(ptr: regulator); |
79 | |
80 | err = regulator_enable(regulator); |
81 | if (err) |
82 | return err; |
83 | |
84 | hwmon_dev = devm_hwmon_device_register_with_info(dev: &pdev->dev, |
85 | name: "sy7636a_temperature" , drvdata: regmap, |
86 | info: &sy7636a_chip_info, NULL); |
87 | |
88 | if (IS_ERR(ptr: hwmon_dev)) { |
89 | err = PTR_ERR(ptr: hwmon_dev); |
90 | dev_err(&pdev->dev, "Unable to register hwmon device, returned %d\n" , err); |
91 | return err; |
92 | } |
93 | |
94 | return 0; |
95 | } |
96 | |
97 | static struct platform_driver sy7636a_sensor_driver = { |
98 | .probe = sy7636a_sensor_probe, |
99 | .driver = { |
100 | .name = "sy7636a-temperature" , |
101 | }, |
102 | }; |
103 | module_platform_driver(sy7636a_sensor_driver); |
104 | |
105 | MODULE_DESCRIPTION("SY7636A sensor driver" ); |
106 | MODULE_LICENSE("GPL" ); |
107 | |