1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Hardware monitoring driver for Analog Devices LT3074
4 *
5 * Copyright (C) 2025 Analog Devices, Inc.
6 */
7 #include <linux/err.h>
8 #include <linux/i2c.h>
9 #include <linux/mod_devicetable.h>
10 #include <linux/module.h>
11
12 #include "pmbus.h"
13
14 #define LT3074_MFR_READ_VBIAS 0xc6
15 #define LT3074_MFR_BIAS_OV_WARN_LIMIT 0xc7
16 #define LT3074_MFR_BIAS_UV_WARN_LIMIT 0xc8
17 #define LT3074_MFR_SPECIAL_ID 0xe7
18
19 #define LT3074_SPECIAL_ID_VALUE 0x1c1d
20
21 static const struct regulator_desc __maybe_unused lt3074_reg_desc[] = {
22 PMBUS_REGULATOR_ONE("regulator"),
23 };
24
lt3074_read_word_data(struct i2c_client * client,int page,int phase,int reg)25 static int lt3074_read_word_data(struct i2c_client *client, int page,
26 int phase, int reg)
27 {
28 switch (reg) {
29 case PMBUS_VIRT_READ_VMON:
30 return pmbus_read_word_data(client, page, phase,
31 LT3074_MFR_READ_VBIAS);
32 case PMBUS_VIRT_VMON_UV_WARN_LIMIT:
33 return pmbus_read_word_data(client, page, phase,
34 LT3074_MFR_BIAS_UV_WARN_LIMIT);
35 case PMBUS_VIRT_VMON_OV_WARN_LIMIT:
36 return pmbus_read_word_data(client, page, phase,
37 LT3074_MFR_BIAS_OV_WARN_LIMIT);
38 default:
39 return -ENODATA;
40 }
41 }
42
lt3074_write_word_data(struct i2c_client * client,int page,int reg,u16 word)43 static int lt3074_write_word_data(struct i2c_client *client, int page,
44 int reg, u16 word)
45 {
46 switch (reg) {
47 case PMBUS_VIRT_VMON_UV_WARN_LIMIT:
48 return pmbus_write_word_data(client, 0,
49 LT3074_MFR_BIAS_UV_WARN_LIMIT,
50 word);
51 case PMBUS_VIRT_VMON_OV_WARN_LIMIT:
52 return pmbus_write_word_data(client, 0,
53 LT3074_MFR_BIAS_OV_WARN_LIMIT,
54 word);
55 default:
56 return -ENODATA;
57 }
58 }
59
60 static struct pmbus_driver_info lt3074_info = {
61 .pages = 1,
62 .format[PSC_VOLTAGE_IN] = linear,
63 .format[PSC_VOLTAGE_OUT] = linear,
64 .format[PSC_CURRENT_OUT] = linear,
65 .format[PSC_TEMPERATURE] = linear,
66 .func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT |
67 PMBUS_HAVE_TEMP | PMBUS_HAVE_VMON |
68 PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_STATUS_IOUT |
69 PMBUS_HAVE_STATUS_INPUT | PMBUS_HAVE_STATUS_TEMP,
70 .read_word_data = lt3074_read_word_data,
71 .write_word_data = lt3074_write_word_data,
72 #if IS_ENABLED(CONFIG_SENSORS_LT3074_REGULATOR)
73 .num_regulators = 1,
74 .reg_desc = lt3074_reg_desc,
75 #endif
76 };
77
lt3074_probe(struct i2c_client * client)78 static int lt3074_probe(struct i2c_client *client)
79 {
80 int ret;
81 struct device *dev = &client->dev;
82
83 if (!i2c_check_functionality(client->adapter,
84 I2C_FUNC_SMBUS_READ_WORD_DATA))
85 return -ENODEV;
86
87 ret = i2c_smbus_read_word_data(client, LT3074_MFR_SPECIAL_ID);
88 if (ret < 0)
89 return dev_err_probe(dev, ret, "Failed to read ID\n");
90
91 if (ret != LT3074_SPECIAL_ID_VALUE)
92 return dev_err_probe(dev, -ENODEV, "ID mismatch\n");
93
94 return pmbus_do_probe(client, <3074_info);
95 }
96
97 static const struct i2c_device_id lt3074_id[] = {
98 { "lt3074", 0 },
99 {}
100 };
101 MODULE_DEVICE_TABLE(i2c, lt3074_id);
102
103 static const struct of_device_id __maybe_unused lt3074_of_match[] = {
104 { .compatible = "adi,lt3074" },
105 {}
106 };
107 MODULE_DEVICE_TABLE(of, lt3074_of_match);
108
109 static struct i2c_driver lt3074_driver = {
110 .driver = {
111 .name = "lt3074",
112 .of_match_table = of_match_ptr(lt3074_of_match),
113 },
114 .probe = lt3074_probe,
115 .id_table = lt3074_id,
116 };
117 module_i2c_driver(lt3074_driver);
118
119 MODULE_AUTHOR("Cedric Encarnacion <cedricjustine.encarnacion@analog.com>");
120 MODULE_DESCRIPTION("PMBus driver for Analog Devices LT3074");
121 MODULE_LICENSE("GPL");
122 MODULE_IMPORT_NS("PMBUS");
123