1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * Hardware monitoring driver for LTC3815 |
4 | * |
5 | * Copyright (c) 2015 Linear Technology |
6 | * Copyright (c) 2015 Guenter Roeck |
7 | */ |
8 | |
9 | #include <linux/err.h> |
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> |
15 | #include "pmbus.h" |
16 | |
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 |
23 | |
24 | #define LTC3815_ID 0x8000 |
25 | #define LTC3815_ID_MASK 0xff00 |
26 | |
27 | static int ltc3815_read_byte_data(struct i2c_client *client, int page, int reg) |
28 | { |
29 | int ret; |
30 | |
31 | switch (reg) { |
32 | case PMBUS_VOUT_MODE: |
33 | /* |
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. |
38 | */ |
39 | ret = 0x40; |
40 | break; |
41 | default: |
42 | ret = -ENODATA; |
43 | break; |
44 | } |
45 | return ret; |
46 | } |
47 | |
48 | static int ltc3815_write_byte(struct i2c_client *client, int page, u8 reg) |
49 | { |
50 | int ret; |
51 | |
52 | switch (reg) { |
53 | case PMBUS_CLEAR_FAULTS: |
54 | /* |
55 | * LTC3815 does not support the CLEAR_FAULTS command. |
56 | * Emulate it by clearing the status register. |
57 | */ |
58 | ret = pmbus_read_word_data(client, page: 0, phase: 0xff, reg: PMBUS_STATUS_WORD); |
59 | if (ret > 0) { |
60 | pmbus_write_word_data(client, page: 0, reg: PMBUS_STATUS_WORD, |
61 | word: ret); |
62 | ret = 0; |
63 | } |
64 | break; |
65 | default: |
66 | ret = -ENODATA; |
67 | break; |
68 | } |
69 | return ret; |
70 | } |
71 | |
72 | static int ltc3815_read_word_data(struct i2c_client *client, int page, |
73 | int phase, int reg) |
74 | { |
75 | int ret; |
76 | |
77 | switch (reg) { |
78 | case PMBUS_VIRT_READ_VIN_MAX: |
79 | ret = pmbus_read_word_data(client, page, phase, |
80 | LTC3815_MFR_VIN_PEAK); |
81 | break; |
82 | case PMBUS_VIRT_READ_VOUT_MAX: |
83 | ret = pmbus_read_word_data(client, page, phase, |
84 | LTC3815_MFR_VOUT_PEAK); |
85 | break; |
86 | case PMBUS_VIRT_READ_TEMP_MAX: |
87 | ret = pmbus_read_word_data(client, page, phase, |
88 | LTC3815_MFR_TEMP_PEAK); |
89 | break; |
90 | case PMBUS_VIRT_READ_IOUT_MAX: |
91 | ret = pmbus_read_word_data(client, page, phase, |
92 | LTC3815_MFR_IOUT_PEAK); |
93 | break; |
94 | case PMBUS_VIRT_READ_IIN_MAX: |
95 | ret = pmbus_read_word_data(client, page, phase, |
96 | LTC3815_MFR_IIN_PEAK); |
97 | break; |
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: |
103 | ret = 0; |
104 | break; |
105 | default: |
106 | ret = -ENODATA; |
107 | break; |
108 | } |
109 | return ret; |
110 | } |
111 | |
112 | static int ltc3815_write_word_data(struct i2c_client *client, int page, |
113 | int reg, u16 word) |
114 | { |
115 | int ret; |
116 | |
117 | switch (reg) { |
118 | case PMBUS_VIRT_RESET_IIN_HISTORY: |
119 | ret = pmbus_write_word_data(client, page, |
120 | LTC3815_MFR_IIN_PEAK, word: 0); |
121 | break; |
122 | case PMBUS_VIRT_RESET_IOUT_HISTORY: |
123 | ret = pmbus_write_word_data(client, page, |
124 | LTC3815_MFR_IOUT_PEAK, word: 0); |
125 | break; |
126 | case PMBUS_VIRT_RESET_VOUT_HISTORY: |
127 | ret = pmbus_write_word_data(client, page, |
128 | LTC3815_MFR_VOUT_PEAK, word: 0); |
129 | break; |
130 | case PMBUS_VIRT_RESET_VIN_HISTORY: |
131 | ret = pmbus_write_word_data(client, page, |
132 | LTC3815_MFR_VIN_PEAK, word: 0); |
133 | break; |
134 | case PMBUS_VIRT_RESET_TEMP_HISTORY: |
135 | ret = pmbus_write_word_data(client, page, |
136 | LTC3815_MFR_TEMP_PEAK, word: 0); |
137 | break; |
138 | default: |
139 | ret = -ENODATA; |
140 | break; |
141 | } |
142 | return ret; |
143 | } |
144 | |
145 | static const struct i2c_device_id ltc3815_id[] = { |
146 | {"ltc3815" , 0}, |
147 | { } |
148 | }; |
149 | MODULE_DEVICE_TABLE(i2c, ltc3815_id); |
150 | |
151 | static struct pmbus_driver_info ltc3815_info = { |
152 | .pages = 1, |
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, |
179 | }; |
180 | |
181 | static int ltc3815_probe(struct i2c_client *client) |
182 | { |
183 | int chip_id; |
184 | |
185 | if (!i2c_check_functionality(adap: client->adapter, |
186 | I2C_FUNC_SMBUS_READ_WORD_DATA)) |
187 | return -ENODEV; |
188 | |
189 | chip_id = i2c_smbus_read_word_data(client, LTC3815_MFR_SPECIAL_ID); |
190 | if (chip_id < 0) |
191 | return chip_id; |
192 | if ((chip_id & LTC3815_ID_MASK) != LTC3815_ID) |
193 | return -ENODEV; |
194 | |
195 | return pmbus_do_probe(client, info: <c3815_info); |
196 | } |
197 | |
198 | static struct i2c_driver ltc3815_driver = { |
199 | .driver = { |
200 | .name = "ltc3815" , |
201 | }, |
202 | .probe = ltc3815_probe, |
203 | .id_table = ltc3815_id, |
204 | }; |
205 | |
206 | module_i2c_driver(ltc3815_driver); |
207 | |
208 | MODULE_AUTHOR("Guenter Roeck" ); |
209 | MODULE_DESCRIPTION("PMBus driver for LTC3815" ); |
210 | MODULE_LICENSE("GPL" ); |
211 | MODULE_IMPORT_NS(PMBUS); |
212 | |