1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Hardware monitoring driver for LTC3815
5 * Copyright (c) 2015 Linear Technology
6 * Copyright (c) 2015 Guenter Roeck
10 #include <linux/i2c.h>
11 #include <linux/init.h>
12 #include <linux/jiffies.h>
13 #include <linux/kernel.h>
14 #include <linux/module.h>
17 #define LTC3815_MFR_IOUT_PEAK 0xd7
18 #define LTC3815_MFR_VOUT_PEAK 0xdd
19 #define LTC3815_MFR_VIN_PEAK 0xde
20 #define LTC3815_MFR_TEMP_PEAK 0xdf
21 #define LTC3815_MFR_IIN_PEAK 0xe1
22 #define LTC3815_MFR_SPECIAL_ID 0xe7
24 #define LTC3815_ID 0x8000
25 #define LTC3815_ID_MASK 0xff00
27 static int ltc3815_read_byte_data(struct i2c_client *client, int page, int reg)
34 * The chip returns 0x3e, suggesting VID mode with manufacturer
35 * specific VID codes. Since the output voltage is reported
36 * with a LSB of 0.5mV, override and report direct mode with
37 * appropriate coefficients.
48 static int ltc3815_write_byte(struct i2c_client *client, int page, u8 reg)
53 case PMBUS_CLEAR_FAULTS:
55 * LTC3815 does not support the CLEAR_FAULTS command.
56 * Emulate it by clearing the status register.
58 ret = pmbus_read_word_data(client, 0, PMBUS_STATUS_WORD);
60 pmbus_write_word_data(client, 0, PMBUS_STATUS_WORD,
72 static int ltc3815_read_word_data(struct i2c_client *client, int page, int reg)
77 case PMBUS_VIRT_READ_VIN_MAX:
78 ret = pmbus_read_word_data(client, page, LTC3815_MFR_VIN_PEAK);
80 case PMBUS_VIRT_READ_VOUT_MAX:
81 ret = pmbus_read_word_data(client, page, LTC3815_MFR_VOUT_PEAK);
83 case PMBUS_VIRT_READ_TEMP_MAX:
84 ret = pmbus_read_word_data(client, page, LTC3815_MFR_TEMP_PEAK);
86 case PMBUS_VIRT_READ_IOUT_MAX:
87 ret = pmbus_read_word_data(client, page, LTC3815_MFR_IOUT_PEAK);
89 case PMBUS_VIRT_READ_IIN_MAX:
90 ret = pmbus_read_word_data(client, page, LTC3815_MFR_IIN_PEAK);
92 case PMBUS_VIRT_RESET_VOUT_HISTORY:
93 case PMBUS_VIRT_RESET_VIN_HISTORY:
94 case PMBUS_VIRT_RESET_TEMP_HISTORY:
95 case PMBUS_VIRT_RESET_IOUT_HISTORY:
96 case PMBUS_VIRT_RESET_IIN_HISTORY:
106 static int ltc3815_write_word_data(struct i2c_client *client, int page,
112 case PMBUS_VIRT_RESET_IIN_HISTORY:
113 ret = pmbus_write_word_data(client, page,
114 LTC3815_MFR_IIN_PEAK, 0);
116 case PMBUS_VIRT_RESET_IOUT_HISTORY:
117 ret = pmbus_write_word_data(client, page,
118 LTC3815_MFR_IOUT_PEAK, 0);
120 case PMBUS_VIRT_RESET_VOUT_HISTORY:
121 ret = pmbus_write_word_data(client, page,
122 LTC3815_MFR_VOUT_PEAK, 0);
124 case PMBUS_VIRT_RESET_VIN_HISTORY:
125 ret = pmbus_write_word_data(client, page,
126 LTC3815_MFR_VIN_PEAK, 0);
128 case PMBUS_VIRT_RESET_TEMP_HISTORY:
129 ret = pmbus_write_word_data(client, page,
130 LTC3815_MFR_TEMP_PEAK, 0);
139 static const struct i2c_device_id ltc3815_id[] = {
143 MODULE_DEVICE_TABLE(i2c, ltc3815_id);
145 static struct pmbus_driver_info ltc3815_info = {
147 .format[PSC_VOLTAGE_IN] = direct,
148 .format[PSC_VOLTAGE_OUT] = direct,
149 .format[PSC_CURRENT_IN] = direct,
150 .format[PSC_CURRENT_OUT] = direct,
151 .format[PSC_TEMPERATURE] = direct,
152 .m[PSC_VOLTAGE_IN] = 250,
153 .b[PSC_VOLTAGE_IN] = 0,
154 .R[PSC_VOLTAGE_IN] = 0,
155 .m[PSC_VOLTAGE_OUT] = 2,
156 .b[PSC_VOLTAGE_OUT] = 0,
157 .R[PSC_VOLTAGE_OUT] = 3,
158 .m[PSC_CURRENT_IN] = 1,
159 .b[PSC_CURRENT_IN] = 0,
160 .R[PSC_CURRENT_IN] = 2,
161 .m[PSC_CURRENT_OUT] = 1,
162 .b[PSC_CURRENT_OUT] = 0,
163 .R[PSC_CURRENT_OUT] = 2,
164 .m[PSC_TEMPERATURE] = 1,
165 .b[PSC_TEMPERATURE] = 0,
166 .R[PSC_TEMPERATURE] = 0,
167 .func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_IIN | PMBUS_HAVE_VOUT |
168 PMBUS_HAVE_IOUT | PMBUS_HAVE_TEMP,
169 .read_byte_data = ltc3815_read_byte_data,
170 .read_word_data = ltc3815_read_word_data,
171 .write_byte = ltc3815_write_byte,
172 .write_word_data = ltc3815_write_word_data,
175 static int ltc3815_probe(struct i2c_client *client,
176 const struct i2c_device_id *id)
180 if (!i2c_check_functionality(client->adapter,
181 I2C_FUNC_SMBUS_READ_WORD_DATA))
184 chip_id = i2c_smbus_read_word_data(client, LTC3815_MFR_SPECIAL_ID);
187 if ((chip_id & LTC3815_ID_MASK) != LTC3815_ID)
190 return pmbus_do_probe(client, id, <c3815_info);
193 static struct i2c_driver ltc3815_driver = {
197 .probe = ltc3815_probe,
198 .remove = pmbus_do_remove,
199 .id_table = ltc3815_id,
202 module_i2c_driver(ltc3815_driver);
204 MODULE_AUTHOR("Guenter Roeck");
205 MODULE_DESCRIPTION("PMBus driver for LTC3815");
206 MODULE_LICENSE("GPL");