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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * max31722 - hwmon driver for Maxim Integrated MAX31722/MAX31723 SPI
4 * digital thermometer and thermostats.
5 *
6 * Copyright (c) 2016, Intel Corporation.
7 */
8
9#include <linux/hwmon.h>
10#include <linux/hwmon-sysfs.h>
11#include <linux/kernel.h>
12#include <linux/module.h>
13#include <linux/spi/spi.h>
14
15#define MAX31722_REG_CFG 0x00
16#define MAX31722_REG_TEMP_LSB 0x01
17
18#define MAX31722_MODE_CONTINUOUS 0x00
19#define MAX31722_MODE_STANDBY 0x01
20#define MAX31722_MODE_MASK 0xFE
21#define MAX31722_RESOLUTION_12BIT 0x06
22#define MAX31722_WRITE_MASK 0x80
23
24struct max31722_data {
25 struct device *hwmon_dev;
26 struct spi_device *spi_device;
27 u8 mode;
28};
29
30static int max31722_set_mode(struct max31722_data *data, u8 mode)
31{
32 int ret;
33 struct spi_device *spi = data->spi_device;
34 u8 buf[2] = {
35 MAX31722_REG_CFG | MAX31722_WRITE_MASK,
36 (data->mode & MAX31722_MODE_MASK) | mode
37 };
38
39 ret = spi_write(spi, &buf, sizeof(buf));
40 if (ret < 0) {
41 dev_err(&spi->dev, "failed to set sensor mode.\n");
42 return ret;
43 }
44 data->mode = (data->mode & MAX31722_MODE_MASK) | mode;
45
46 return 0;
47}
48
49static ssize_t max31722_temp_show(struct device *dev,
50 struct device_attribute *attr, char *buf)
51{
52 ssize_t ret;
53 struct max31722_data *data = dev_get_drvdata(dev);
54
55 ret = spi_w8r16(data->spi_device, MAX31722_REG_TEMP_LSB);
56 if (ret < 0)
57 return ret;
58 /* Keep 12 bits and multiply by the scale of 62.5 millidegrees/bit. */
59 return sprintf(buf, "%d\n", (s16)le16_to_cpu(ret) * 125 / 32);
60}
61
62static SENSOR_DEVICE_ATTR_RO(temp1_input, max31722_temp, 0);
63
64static struct attribute *max31722_attrs[] = {
65 &sensor_dev_attr_temp1_input.dev_attr.attr,
66 NULL,
67};
68
69ATTRIBUTE_GROUPS(max31722);
70
71static int max31722_probe(struct spi_device *spi)
72{
73 int ret;
74 struct max31722_data *data;
75
76 data = devm_kzalloc(&spi->dev, sizeof(*data), GFP_KERNEL);
77 if (!data)
78 return -ENOMEM;
79
80 spi_set_drvdata(spi, data);
81 data->spi_device = spi;
82 /*
83 * Set SD bit to 0 so we can have continuous measurements.
84 * Set resolution to 12 bits for maximum precision.
85 */
86 data->mode = MAX31722_MODE_CONTINUOUS | MAX31722_RESOLUTION_12BIT;
87 ret = max31722_set_mode(data, MAX31722_MODE_CONTINUOUS);
88 if (ret < 0)
89 return ret;
90
91 data->hwmon_dev = hwmon_device_register_with_groups(&spi->dev,
92 spi->modalias,
93 data,
94 max31722_groups);
95 if (IS_ERR(data->hwmon_dev)) {
96 max31722_set_mode(data, MAX31722_MODE_STANDBY);
97 return PTR_ERR(data->hwmon_dev);
98 }
99
100 return 0;
101}
102
103static void max31722_remove(struct spi_device *spi)
104{
105 struct max31722_data *data = spi_get_drvdata(spi);
106 int ret;
107
108 hwmon_device_unregister(data->hwmon_dev);
109
110 ret = max31722_set_mode(data, MAX31722_MODE_STANDBY);
111 if (ret)
112 /* There is nothing we can do about this ... */
113 dev_warn(&spi->dev, "Failed to put device in stand-by mode\n");
114}
115
116static int max31722_suspend(struct device *dev)
117{
118 struct spi_device *spi_device = to_spi_device(dev);
119 struct max31722_data *data = spi_get_drvdata(spi_device);
120
121 return max31722_set_mode(data, MAX31722_MODE_STANDBY);
122}
123
124static int max31722_resume(struct device *dev)
125{
126 struct spi_device *spi_device = to_spi_device(dev);
127 struct max31722_data *data = spi_get_drvdata(spi_device);
128
129 return max31722_set_mode(data, MAX31722_MODE_CONTINUOUS);
130}
131
132static DEFINE_SIMPLE_DEV_PM_OPS(max31722_pm_ops, max31722_suspend, max31722_resume);
133
134static const struct spi_device_id max31722_spi_id[] = {
135 {"max31722", 0},
136 {"max31723", 0},
137 {}
138};
139MODULE_DEVICE_TABLE(spi, max31722_spi_id);
140
141static struct spi_driver max31722_driver = {
142 .driver = {
143 .name = "max31722",
144 .pm = pm_sleep_ptr(&max31722_pm_ops),
145 },
146 .probe = max31722_probe,
147 .remove = max31722_remove,
148 .id_table = max31722_spi_id,
149};
150
151module_spi_driver(max31722_driver);
152
153MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>");
154MODULE_DESCRIPTION("max31722 sensor driver");
155MODULE_LICENSE("GPL v2");
1/*
2 * max31722 - hwmon driver for Maxim Integrated MAX31722/MAX31723 SPI
3 * digital thermometer and thermostats.
4 *
5 * Copyright (c) 2016, Intel Corporation.
6 *
7 * This file is subject to the terms and conditions of version 2 of
8 * the GNU General Public License. See the file COPYING in the main
9 * directory of this archive for more details.
10 */
11
12#include <linux/acpi.h>
13#include <linux/hwmon.h>
14#include <linux/hwmon-sysfs.h>
15#include <linux/kernel.h>
16#include <linux/module.h>
17#include <linux/spi/spi.h>
18
19#define MAX31722_REG_CFG 0x00
20#define MAX31722_REG_TEMP_LSB 0x01
21
22#define MAX31722_MODE_CONTINUOUS 0x00
23#define MAX31722_MODE_STANDBY 0x01
24#define MAX31722_MODE_MASK 0xFE
25#define MAX31722_RESOLUTION_12BIT 0x06
26#define MAX31722_WRITE_MASK 0x80
27
28struct max31722_data {
29 struct device *hwmon_dev;
30 struct spi_device *spi_device;
31 u8 mode;
32};
33
34static int max31722_set_mode(struct max31722_data *data, u8 mode)
35{
36 int ret;
37 struct spi_device *spi = data->spi_device;
38 u8 buf[2] = {
39 MAX31722_REG_CFG | MAX31722_WRITE_MASK,
40 (data->mode & MAX31722_MODE_MASK) | mode
41 };
42
43 ret = spi_write(spi, &buf, sizeof(buf));
44 if (ret < 0) {
45 dev_err(&spi->dev, "failed to set sensor mode.\n");
46 return ret;
47 }
48 data->mode = (data->mode & MAX31722_MODE_MASK) | mode;
49
50 return 0;
51}
52
53static ssize_t max31722_show_temp(struct device *dev,
54 struct device_attribute *attr,
55 char *buf)
56{
57 ssize_t ret;
58 struct max31722_data *data = dev_get_drvdata(dev);
59
60 ret = spi_w8r16(data->spi_device, MAX31722_REG_TEMP_LSB);
61 if (ret < 0)
62 return ret;
63 /* Keep 12 bits and multiply by the scale of 62.5 millidegrees/bit. */
64 return sprintf(buf, "%d\n", (s16)le16_to_cpu(ret) * 125 / 32);
65}
66
67static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO,
68 max31722_show_temp, NULL, 0);
69
70static struct attribute *max31722_attrs[] = {
71 &sensor_dev_attr_temp1_input.dev_attr.attr,
72 NULL,
73};
74
75ATTRIBUTE_GROUPS(max31722);
76
77static int max31722_probe(struct spi_device *spi)
78{
79 int ret;
80 struct max31722_data *data;
81
82 data = devm_kzalloc(&spi->dev, sizeof(*data), GFP_KERNEL);
83 if (!data)
84 return -ENOMEM;
85
86 spi_set_drvdata(spi, data);
87 data->spi_device = spi;
88 /*
89 * Set SD bit to 0 so we can have continuous measurements.
90 * Set resolution to 12 bits for maximum precision.
91 */
92 data->mode = MAX31722_MODE_CONTINUOUS | MAX31722_RESOLUTION_12BIT;
93 ret = max31722_set_mode(data, MAX31722_MODE_CONTINUOUS);
94 if (ret < 0)
95 return ret;
96
97 data->hwmon_dev = hwmon_device_register_with_groups(&spi->dev,
98 spi->modalias,
99 data,
100 max31722_groups);
101 if (IS_ERR(data->hwmon_dev)) {
102 max31722_set_mode(data, MAX31722_MODE_STANDBY);
103 return PTR_ERR(data->hwmon_dev);
104 }
105
106 return 0;
107}
108
109static int max31722_remove(struct spi_device *spi)
110{
111 struct max31722_data *data = spi_get_drvdata(spi);
112
113 hwmon_device_unregister(data->hwmon_dev);
114
115 return max31722_set_mode(data, MAX31722_MODE_STANDBY);
116}
117
118static int __maybe_unused max31722_suspend(struct device *dev)
119{
120 struct spi_device *spi_device = to_spi_device(dev);
121 struct max31722_data *data = spi_get_drvdata(spi_device);
122
123 return max31722_set_mode(data, MAX31722_MODE_STANDBY);
124}
125
126static int __maybe_unused max31722_resume(struct device *dev)
127{
128 struct spi_device *spi_device = to_spi_device(dev);
129 struct max31722_data *data = spi_get_drvdata(spi_device);
130
131 return max31722_set_mode(data, MAX31722_MODE_CONTINUOUS);
132}
133
134static SIMPLE_DEV_PM_OPS(max31722_pm_ops, max31722_suspend, max31722_resume);
135
136static const struct spi_device_id max31722_spi_id[] = {
137 {"max31722", 0},
138 {"max31723", 0},
139 {}
140};
141
142static const struct acpi_device_id __maybe_unused max31722_acpi_id[] = {
143 {"MAX31722", 0},
144 {"MAX31723", 0},
145 {}
146};
147
148MODULE_DEVICE_TABLE(spi, max31722_spi_id);
149
150static struct spi_driver max31722_driver = {
151 .driver = {
152 .name = "max31722",
153 .pm = &max31722_pm_ops,
154 .acpi_match_table = ACPI_PTR(max31722_acpi_id),
155 },
156 .probe = max31722_probe,
157 .remove = max31722_remove,
158 .id_table = max31722_spi_id,
159};
160
161module_spi_driver(max31722_driver);
162
163MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>");
164MODULE_DESCRIPTION("max31722 sensor driver");
165MODULE_LICENSE("GPL v2");