1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Hardware monitoring driver for Analog Devices LT7182S
4 *
5 * Copyright (c) 2022 Guenter Roeck
6 *
7 */
8
9 #include <linux/bits.h>
10 #include <linux/err.h>
11 #include <linux/i2c.h>
12 #include <linux/init.h>
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/of.h>
16 #include "pmbus.h"
17
18 #define LT7182S_NUM_PAGES 2
19
20 #define MFR_READ_EXTVCC 0xcd
21 #define MFR_READ_ITH 0xce
22 #define MFR_CONFIG_ALL_LT7182S 0xd1
23 #define MFR_IOUT_PEAK 0xd7
24 #define MFR_ADC_CONTROL_LT7182S 0xd8
25
26 #define MFR_DEBUG_TELEMETRY BIT(0)
27
28 #define MFR_VOUT_PEAK 0xdd
29 #define MFR_VIN_PEAK 0xde
30 #define MFR_TEMPERATURE_1_PEAK 0xdf
31 #define MFR_CLEAR_PEAKS 0xe3
32
33 #define MFR_CONFIG_IEEE BIT(8)
34
lt7182s_read_word_data(struct i2c_client * client,int page,int phase,int reg)35 static int lt7182s_read_word_data(struct i2c_client *client, int page, int phase, int reg)
36 {
37 int ret;
38
39 switch (reg) {
40 case PMBUS_VIRT_READ_VMON:
41 if (page == 0 || page == 1)
42 ret = pmbus_read_word_data(client, page, phase, MFR_READ_ITH);
43 else
44 ret = pmbus_read_word_data(client, 0, phase, MFR_READ_EXTVCC);
45 break;
46 case PMBUS_VIRT_READ_IOUT_MAX:
47 ret = pmbus_read_word_data(client, page, phase, MFR_IOUT_PEAK);
48 break;
49 case PMBUS_VIRT_READ_VOUT_MAX:
50 ret = pmbus_read_word_data(client, page, phase, MFR_VOUT_PEAK);
51 break;
52 case PMBUS_VIRT_READ_VIN_MAX:
53 ret = pmbus_read_word_data(client, page, phase, MFR_VIN_PEAK);
54 break;
55 case PMBUS_VIRT_READ_TEMP_MAX:
56 ret = pmbus_read_word_data(client, page, phase, MFR_TEMPERATURE_1_PEAK);
57 break;
58 case PMBUS_VIRT_RESET_VIN_HISTORY:
59 ret = (page == 0) ? 0 : -ENODATA;
60 break;
61 default:
62 ret = -ENODATA;
63 break;
64 }
65 return ret;
66 }
67
lt7182s_write_word_data(struct i2c_client * client,int page,int reg,u16 word)68 static int lt7182s_write_word_data(struct i2c_client *client, int page, int reg, u16 word)
69 {
70 int ret;
71
72 switch (reg) {
73 case PMBUS_VIRT_RESET_VIN_HISTORY:
74 ret = pmbus_write_byte(client, 0, MFR_CLEAR_PEAKS);
75 break;
76 default:
77 ret = -ENODATA;
78 break;
79 }
80 return ret;
81 }
82
83 static struct pmbus_driver_info lt7182s_info = {
84 .pages = LT7182S_NUM_PAGES,
85 .format[PSC_VOLTAGE_IN] = linear,
86 .format[PSC_VOLTAGE_OUT] = linear,
87 .format[PSC_CURRENT_IN] = linear,
88 .format[PSC_CURRENT_OUT] = linear,
89 .format[PSC_TEMPERATURE] = linear,
90 .format[PSC_POWER] = linear,
91 .func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT |
92 PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT | PMBUS_HAVE_POUT |
93 PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_STATUS_IOUT |
94 PMBUS_HAVE_STATUS_INPUT | PMBUS_HAVE_STATUS_TEMP,
95 .func[1] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT |
96 PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT | PMBUS_HAVE_POUT |
97 PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_STATUS_IOUT |
98 PMBUS_HAVE_STATUS_INPUT,
99 .read_word_data = lt7182s_read_word_data,
100 .write_word_data = lt7182s_write_word_data,
101 };
102
lt7182s_probe(struct i2c_client * client)103 static int lt7182s_probe(struct i2c_client *client)
104 {
105 struct device *dev = &client->dev;
106 struct pmbus_driver_info *info;
107 u8 buf[I2C_SMBUS_BLOCK_MAX + 1];
108 int ret;
109
110 if (!i2c_check_functionality(client->adapter,
111 I2C_FUNC_SMBUS_READ_BYTE_DATA |
112 I2C_FUNC_SMBUS_READ_WORD_DATA |
113 I2C_FUNC_SMBUS_READ_BLOCK_DATA))
114 return -ENODEV;
115
116 ret = i2c_smbus_read_block_data(client, PMBUS_MFR_ID, buf);
117 if (ret < 0) {
118 dev_err(dev, "Failed to read PMBUS_MFR_ID\n");
119 return ret;
120 }
121 if (ret != 3 || strncmp(buf, "ADI", 3)) {
122 buf[ret] = '\0';
123 dev_err(dev, "Manufacturer '%s' not supported\n", buf);
124 return -ENODEV;
125 }
126
127 ret = i2c_smbus_read_block_data(client, PMBUS_MFR_MODEL, buf);
128 if (ret < 0) {
129 dev_err(dev, "Failed to read PMBUS_MFR_MODEL\n");
130 return ret;
131 }
132 if (ret != 7 || strncmp(buf, "LT7182S", 7)) {
133 buf[ret] = '\0';
134 dev_err(dev, "Model '%s' not supported\n", buf);
135 return -ENODEV;
136 }
137
138 info = devm_kmemdup(dev, <7182s_info,
139 sizeof(struct pmbus_driver_info), GFP_KERNEL);
140 if (!info)
141 return -ENOMEM;
142
143 /* Set data format to IEEE754 if configured */
144 ret = i2c_smbus_read_word_data(client, MFR_CONFIG_ALL_LT7182S);
145 if (ret < 0)
146 return ret;
147 if (ret & MFR_CONFIG_IEEE) {
148 info->format[PSC_VOLTAGE_IN] = ieee754;
149 info->format[PSC_VOLTAGE_OUT] = ieee754;
150 info->format[PSC_CURRENT_IN] = ieee754;
151 info->format[PSC_CURRENT_OUT] = ieee754;
152 info->format[PSC_TEMPERATURE] = ieee754;
153 info->format[PSC_POWER] = ieee754;
154 }
155
156 /* Enable VMON output if configured */
157 ret = i2c_smbus_read_byte_data(client, MFR_ADC_CONTROL_LT7182S);
158 if (ret < 0)
159 return ret;
160 if (ret & MFR_DEBUG_TELEMETRY) {
161 info->pages = 3;
162 info->func[0] |= PMBUS_HAVE_VMON;
163 info->func[1] |= PMBUS_HAVE_VMON;
164 info->func[2] = PMBUS_HAVE_VMON;
165 }
166
167 return pmbus_do_probe(client, info);
168 }
169
170 static const struct i2c_device_id lt7182s_id[] = {
171 { "lt7182s", 0 },
172 {}
173 };
174 MODULE_DEVICE_TABLE(i2c, lt7182s_id);
175
176 static const struct of_device_id __maybe_unused lt7182s_of_match[] = {
177 { .compatible = "adi,lt7182s" },
178 {}
179 };
180
181 static struct i2c_driver lt7182s_driver = {
182 .driver = {
183 .name = "lt7182s",
184 .of_match_table = of_match_ptr(lt7182s_of_match),
185 },
186 .probe = lt7182s_probe,
187 .id_table = lt7182s_id,
188 };
189
190 module_i2c_driver(lt7182s_driver);
191
192 MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>");
193 MODULE_DESCRIPTION("PMBus driver for Analog Devices LT7182S");
194 MODULE_LICENSE("GPL");
195 MODULE_IMPORT_NS(PMBUS);
196