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, 0xff, 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
,
78 case PMBUS_VIRT_READ_VIN_MAX
:
79 ret
= pmbus_read_word_data(client
, page
, phase
,
80 LTC3815_MFR_VIN_PEAK
);
82 case PMBUS_VIRT_READ_VOUT_MAX
:
83 ret
= pmbus_read_word_data(client
, page
, phase
,
84 LTC3815_MFR_VOUT_PEAK
);
86 case PMBUS_VIRT_READ_TEMP_MAX
:
87 ret
= pmbus_read_word_data(client
, page
, phase
,
88 LTC3815_MFR_TEMP_PEAK
);
90 case PMBUS_VIRT_READ_IOUT_MAX
:
91 ret
= pmbus_read_word_data(client
, page
, phase
,
92 LTC3815_MFR_IOUT_PEAK
);
94 case PMBUS_VIRT_READ_IIN_MAX
:
95 ret
= pmbus_read_word_data(client
, page
, phase
,
96 LTC3815_MFR_IIN_PEAK
);
98 case PMBUS_VIRT_RESET_VOUT_HISTORY
:
99 case PMBUS_VIRT_RESET_VIN_HISTORY
:
100 case PMBUS_VIRT_RESET_TEMP_HISTORY
:
101 case PMBUS_VIRT_RESET_IOUT_HISTORY
:
102 case PMBUS_VIRT_RESET_IIN_HISTORY
:
112 static int ltc3815_write_word_data(struct i2c_client
*client
, int page
,
118 case PMBUS_VIRT_RESET_IIN_HISTORY
:
119 ret
= pmbus_write_word_data(client
, page
,
120 LTC3815_MFR_IIN_PEAK
, 0);
122 case PMBUS_VIRT_RESET_IOUT_HISTORY
:
123 ret
= pmbus_write_word_data(client
, page
,
124 LTC3815_MFR_IOUT_PEAK
, 0);
126 case PMBUS_VIRT_RESET_VOUT_HISTORY
:
127 ret
= pmbus_write_word_data(client
, page
,
128 LTC3815_MFR_VOUT_PEAK
, 0);
130 case PMBUS_VIRT_RESET_VIN_HISTORY
:
131 ret
= pmbus_write_word_data(client
, page
,
132 LTC3815_MFR_VIN_PEAK
, 0);
134 case PMBUS_VIRT_RESET_TEMP_HISTORY
:
135 ret
= pmbus_write_word_data(client
, page
,
136 LTC3815_MFR_TEMP_PEAK
, 0);
145 static const struct i2c_device_id ltc3815_id
[] = {
149 MODULE_DEVICE_TABLE(i2c
, ltc3815_id
);
151 static struct pmbus_driver_info ltc3815_info
= {
153 .format
[PSC_VOLTAGE_IN
] = direct
,
154 .format
[PSC_VOLTAGE_OUT
] = direct
,
155 .format
[PSC_CURRENT_IN
] = direct
,
156 .format
[PSC_CURRENT_OUT
] = direct
,
157 .format
[PSC_TEMPERATURE
] = direct
,
158 .m
[PSC_VOLTAGE_IN
] = 250,
159 .b
[PSC_VOLTAGE_IN
] = 0,
160 .R
[PSC_VOLTAGE_IN
] = 0,
161 .m
[PSC_VOLTAGE_OUT
] = 2,
162 .b
[PSC_VOLTAGE_OUT
] = 0,
163 .R
[PSC_VOLTAGE_OUT
] = 3,
164 .m
[PSC_CURRENT_IN
] = 1,
165 .b
[PSC_CURRENT_IN
] = 0,
166 .R
[PSC_CURRENT_IN
] = 2,
167 .m
[PSC_CURRENT_OUT
] = 1,
168 .b
[PSC_CURRENT_OUT
] = 0,
169 .R
[PSC_CURRENT_OUT
] = 2,
170 .m
[PSC_TEMPERATURE
] = 1,
171 .b
[PSC_TEMPERATURE
] = 0,
172 .R
[PSC_TEMPERATURE
] = 0,
173 .func
[0] = PMBUS_HAVE_VIN
| PMBUS_HAVE_IIN
| PMBUS_HAVE_VOUT
|
174 PMBUS_HAVE_IOUT
| PMBUS_HAVE_TEMP
,
175 .read_byte_data
= ltc3815_read_byte_data
,
176 .read_word_data
= ltc3815_read_word_data
,
177 .write_byte
= ltc3815_write_byte
,
178 .write_word_data
= ltc3815_write_word_data
,
181 static int ltc3815_probe(struct i2c_client
*client
)
185 if (!i2c_check_functionality(client
->adapter
,
186 I2C_FUNC_SMBUS_READ_WORD_DATA
))
189 chip_id
= i2c_smbus_read_word_data(client
, LTC3815_MFR_SPECIAL_ID
);
192 if ((chip_id
& LTC3815_ID_MASK
) != LTC3815_ID
)
195 return pmbus_do_probe(client
, <c3815_info
);
198 static struct i2c_driver ltc3815_driver
= {
202 .probe
= ltc3815_probe
,
203 .id_table
= ltc3815_id
,
206 module_i2c_driver(ltc3815_driver
);
208 MODULE_AUTHOR("Guenter Roeck");
209 MODULE_DESCRIPTION("PMBus driver for LTC3815");
210 MODULE_LICENSE("GPL");
211 MODULE_IMPORT_NS("PMBUS");