Commit | Line | Data |
---|---|---|
36edc939 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
04e1e70a TB |
2 | /* |
3 | * max31722 - hwmon driver for Maxim Integrated MAX31722/MAX31723 SPI | |
4 | * digital thermometer and thermostats. | |
5 | * | |
6 | * Copyright (c) 2016, Intel Corporation. | |
04e1e70a TB |
7 | */ |
8 | ||
9 | #include <linux/acpi.h> | |
10 | #include <linux/hwmon.h> | |
11 | #include <linux/hwmon-sysfs.h> | |
12 | #include <linux/kernel.h> | |
13 | #include <linux/module.h> | |
14 | #include <linux/spi/spi.h> | |
15 | ||
16 | #define MAX31722_REG_CFG 0x00 | |
17 | #define MAX31722_REG_TEMP_LSB 0x01 | |
18 | ||
19 | #define MAX31722_MODE_CONTINUOUS 0x00 | |
20 | #define MAX31722_MODE_STANDBY 0x01 | |
21 | #define MAX31722_MODE_MASK 0xFE | |
22 | #define MAX31722_RESOLUTION_12BIT 0x06 | |
23 | #define MAX31722_WRITE_MASK 0x80 | |
24 | ||
25 | struct max31722_data { | |
26 | struct device *hwmon_dev; | |
27 | struct spi_device *spi_device; | |
28 | u8 mode; | |
29 | }; | |
30 | ||
31 | static int max31722_set_mode(struct max31722_data *data, u8 mode) | |
32 | { | |
33 | int ret; | |
34 | struct spi_device *spi = data->spi_device; | |
35 | u8 buf[2] = { | |
36 | MAX31722_REG_CFG | MAX31722_WRITE_MASK, | |
37 | (data->mode & MAX31722_MODE_MASK) | mode | |
38 | }; | |
39 | ||
40 | ret = spi_write(spi, &buf, sizeof(buf)); | |
41 | if (ret < 0) { | |
42 | dev_err(&spi->dev, "failed to set sensor mode.\n"); | |
43 | return ret; | |
44 | } | |
45 | data->mode = (data->mode & MAX31722_MODE_MASK) | mode; | |
46 | ||
47 | return 0; | |
48 | } | |
49 | ||
845ee709 GR |
50 | static ssize_t max31722_temp_show(struct device *dev, |
51 | struct device_attribute *attr, char *buf) | |
04e1e70a TB |
52 | { |
53 | ssize_t ret; | |
54 | struct max31722_data *data = dev_get_drvdata(dev); | |
55 | ||
56 | ret = spi_w8r16(data->spi_device, MAX31722_REG_TEMP_LSB); | |
57 | if (ret < 0) | |
58 | return ret; | |
59 | /* Keep 12 bits and multiply by the scale of 62.5 millidegrees/bit. */ | |
60 | return sprintf(buf, "%d\n", (s16)le16_to_cpu(ret) * 125 / 32); | |
61 | } | |
62 | ||
845ee709 | 63 | static SENSOR_DEVICE_ATTR_RO(temp1_input, max31722_temp, 0); |
04e1e70a TB |
64 | |
65 | static struct attribute *max31722_attrs[] = { | |
66 | &sensor_dev_attr_temp1_input.dev_attr.attr, | |
67 | NULL, | |
68 | }; | |
69 | ||
70 | ATTRIBUTE_GROUPS(max31722); | |
71 | ||
72 | static int max31722_probe(struct spi_device *spi) | |
73 | { | |
74 | int ret; | |
75 | struct max31722_data *data; | |
76 | ||
77 | data = devm_kzalloc(&spi->dev, sizeof(*data), GFP_KERNEL); | |
78 | if (!data) | |
79 | return -ENOMEM; | |
80 | ||
81 | spi_set_drvdata(spi, data); | |
82 | data->spi_device = spi; | |
83 | /* | |
84 | * Set SD bit to 0 so we can have continuous measurements. | |
85 | * Set resolution to 12 bits for maximum precision. | |
86 | */ | |
87 | data->mode = MAX31722_MODE_CONTINUOUS | MAX31722_RESOLUTION_12BIT; | |
88 | ret = max31722_set_mode(data, MAX31722_MODE_CONTINUOUS); | |
89 | if (ret < 0) | |
90 | return ret; | |
91 | ||
92 | data->hwmon_dev = hwmon_device_register_with_groups(&spi->dev, | |
93 | spi->modalias, | |
94 | data, | |
95 | max31722_groups); | |
96 | if (IS_ERR(data->hwmon_dev)) { | |
97 | max31722_set_mode(data, MAX31722_MODE_STANDBY); | |
98 | return PTR_ERR(data->hwmon_dev); | |
99 | } | |
100 | ||
101 | return 0; | |
102 | } | |
103 | ||
104 | static int max31722_remove(struct spi_device *spi) | |
105 | { | |
106 | struct max31722_data *data = spi_get_drvdata(spi); | |
107 | ||
108 | hwmon_device_unregister(data->hwmon_dev); | |
109 | ||
110 | return max31722_set_mode(data, MAX31722_MODE_STANDBY); | |
111 | } | |
112 | ||
113 | static int __maybe_unused max31722_suspend(struct device *dev) | |
114 | { | |
115 | struct spi_device *spi_device = to_spi_device(dev); | |
116 | struct max31722_data *data = spi_get_drvdata(spi_device); | |
117 | ||
118 | return max31722_set_mode(data, MAX31722_MODE_STANDBY); | |
119 | } | |
120 | ||
121 | static int __maybe_unused max31722_resume(struct device *dev) | |
122 | { | |
123 | struct spi_device *spi_device = to_spi_device(dev); | |
124 | struct max31722_data *data = spi_get_drvdata(spi_device); | |
125 | ||
126 | return max31722_set_mode(data, MAX31722_MODE_CONTINUOUS); | |
127 | } | |
128 | ||
129 | static SIMPLE_DEV_PM_OPS(max31722_pm_ops, max31722_suspend, max31722_resume); | |
130 | ||
131 | static const struct spi_device_id max31722_spi_id[] = { | |
132 | {"max31722", 0}, | |
133 | {"max31723", 0}, | |
134 | {} | |
135 | }; | |
136 | ||
137 | static const struct acpi_device_id __maybe_unused max31722_acpi_id[] = { | |
138 | {"MAX31722", 0}, | |
139 | {"MAX31723", 0}, | |
140 | {} | |
141 | }; | |
142 | ||
143 | MODULE_DEVICE_TABLE(spi, max31722_spi_id); | |
144 | ||
145 | static struct spi_driver max31722_driver = { | |
146 | .driver = { | |
147 | .name = "max31722", | |
148 | .pm = &max31722_pm_ops, | |
149 | .acpi_match_table = ACPI_PTR(max31722_acpi_id), | |
150 | }, | |
151 | .probe = max31722_probe, | |
152 | .remove = max31722_remove, | |
153 | .id_table = max31722_spi_id, | |
154 | }; | |
155 | ||
156 | module_spi_driver(max31722_driver); | |
157 | ||
158 | MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>"); | |
159 | MODULE_DESCRIPTION("max31722 sensor driver"); | |
160 | MODULE_LICENSE("GPL v2"); |