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1 | /* |
2 | * Hardware monitoring driver for LTC3815 | |
3 | * | |
4 | * Copyright (c) 2015 Linear Technology | |
5 | * Copyright (c) 2015 Guenter Roeck | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License as published by | |
9 | * the Free Software Foundation; either version 2 of the License, or | |
10 | * (at your option) any later version. | |
11 | * | |
12 | * This program is distributed in the hope that it will be useful, | |
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | * GNU General Public License for more details. | |
16 | */ | |
17 | ||
18 | #include <linux/err.h> | |
19 | #include <linux/i2c.h> | |
20 | #include <linux/init.h> | |
21 | #include <linux/jiffies.h> | |
22 | #include <linux/kernel.h> | |
23 | #include <linux/module.h> | |
24 | #include "pmbus.h" | |
25 | ||
26 | #define LTC3815_MFR_IOUT_PEAK 0xd7 | |
27 | #define LTC3815_MFR_VOUT_PEAK 0xdd | |
28 | #define LTC3815_MFR_VIN_PEAK 0xde | |
29 | #define LTC3815_MFR_TEMP_PEAK 0xdf | |
30 | #define LTC3815_MFR_IIN_PEAK 0xe1 | |
31 | #define LTC3815_MFR_SPECIAL_ID 0xe7 | |
32 | ||
33 | #define LTC3815_ID 0x8000 | |
34 | #define LTC3815_ID_MASK 0xff00 | |
35 | ||
36 | static int ltc3815_read_byte_data(struct i2c_client *client, int page, int reg) | |
37 | { | |
38 | int ret; | |
39 | ||
40 | switch (reg) { | |
41 | case PMBUS_VOUT_MODE: | |
42 | /* | |
43 | * The chip returns 0x3e, suggesting VID mode with manufacturer | |
44 | * specific VID codes. Since the output voltage is reported | |
45 | * with a LSB of 0.5mV, override and report direct mode with | |
46 | * appropriate coefficients. | |
47 | */ | |
48 | ret = 0x40; | |
49 | break; | |
50 | default: | |
51 | ret = -ENODATA; | |
52 | break; | |
53 | } | |
54 | return ret; | |
55 | } | |
56 | ||
57 | static int ltc3815_write_byte(struct i2c_client *client, int page, u8 reg) | |
58 | { | |
59 | int ret; | |
60 | ||
61 | switch (reg) { | |
62 | case PMBUS_CLEAR_FAULTS: | |
63 | /* | |
64 | * LTC3815 does not support the CLEAR_FAULTS command. | |
65 | * Emulate it by clearing the status register. | |
66 | */ | |
67 | ret = pmbus_read_word_data(client, 0, PMBUS_STATUS_WORD); | |
68 | if (ret > 0) { | |
69 | pmbus_write_word_data(client, 0, PMBUS_STATUS_WORD, | |
70 | ret); | |
71 | ret = 0; | |
72 | } | |
73 | break; | |
74 | default: | |
75 | ret = -ENODATA; | |
76 | break; | |
77 | } | |
78 | return ret; | |
79 | } | |
80 | ||
81 | static int ltc3815_read_word_data(struct i2c_client *client, int page, int reg) | |
82 | { | |
83 | int ret; | |
84 | ||
85 | switch (reg) { | |
86 | case PMBUS_VIRT_READ_VIN_MAX: | |
87 | ret = pmbus_read_word_data(client, page, LTC3815_MFR_VIN_PEAK); | |
88 | break; | |
89 | case PMBUS_VIRT_READ_VOUT_MAX: | |
90 | ret = pmbus_read_word_data(client, page, LTC3815_MFR_VOUT_PEAK); | |
91 | break; | |
92 | case PMBUS_VIRT_READ_TEMP_MAX: | |
93 | ret = pmbus_read_word_data(client, page, LTC3815_MFR_TEMP_PEAK); | |
94 | break; | |
95 | case PMBUS_VIRT_READ_IOUT_MAX: | |
96 | ret = pmbus_read_word_data(client, page, LTC3815_MFR_IOUT_PEAK); | |
97 | break; | |
98 | case PMBUS_VIRT_READ_IIN_MAX: | |
99 | ret = pmbus_read_word_data(client, page, LTC3815_MFR_IIN_PEAK); | |
100 | break; | |
101 | case PMBUS_VIRT_RESET_VOUT_HISTORY: | |
102 | case PMBUS_VIRT_RESET_VIN_HISTORY: | |
103 | case PMBUS_VIRT_RESET_TEMP_HISTORY: | |
104 | case PMBUS_VIRT_RESET_IOUT_HISTORY: | |
105 | case PMBUS_VIRT_RESET_IIN_HISTORY: | |
106 | ret = 0; | |
107 | break; | |
108 | default: | |
109 | ret = -ENODATA; | |
110 | break; | |
111 | } | |
112 | return ret; | |
113 | } | |
114 | ||
115 | static int ltc3815_write_word_data(struct i2c_client *client, int page, | |
116 | int reg, u16 word) | |
117 | { | |
118 | int ret; | |
119 | ||
120 | switch (reg) { | |
121 | case PMBUS_VIRT_RESET_IIN_HISTORY: | |
122 | ret = pmbus_write_word_data(client, page, | |
123 | LTC3815_MFR_IIN_PEAK, 0); | |
124 | break; | |
125 | case PMBUS_VIRT_RESET_IOUT_HISTORY: | |
126 | ret = pmbus_write_word_data(client, page, | |
127 | LTC3815_MFR_IOUT_PEAK, 0); | |
128 | break; | |
129 | case PMBUS_VIRT_RESET_VOUT_HISTORY: | |
130 | ret = pmbus_write_word_data(client, page, | |
131 | LTC3815_MFR_VOUT_PEAK, 0); | |
132 | break; | |
133 | case PMBUS_VIRT_RESET_VIN_HISTORY: | |
134 | ret = pmbus_write_word_data(client, page, | |
135 | LTC3815_MFR_VIN_PEAK, 0); | |
136 | break; | |
137 | case PMBUS_VIRT_RESET_TEMP_HISTORY: | |
138 | ret = pmbus_write_word_data(client, page, | |
139 | LTC3815_MFR_TEMP_PEAK, 0); | |
140 | break; | |
141 | default: | |
142 | ret = -ENODATA; | |
143 | break; | |
144 | } | |
145 | return ret; | |
146 | } | |
147 | ||
148 | static const struct i2c_device_id ltc3815_id[] = { | |
149 | {"ltc3815", 0}, | |
150 | { } | |
151 | }; | |
152 | MODULE_DEVICE_TABLE(i2c, ltc3815_id); | |
153 | ||
154 | static struct pmbus_driver_info ltc3815_info = { | |
155 | .pages = 1, | |
156 | .format[PSC_VOLTAGE_IN] = direct, | |
157 | .format[PSC_VOLTAGE_OUT] = direct, | |
158 | .format[PSC_CURRENT_IN] = direct, | |
159 | .format[PSC_CURRENT_OUT] = direct, | |
160 | .format[PSC_TEMPERATURE] = direct, | |
161 | .m[PSC_VOLTAGE_IN] = 250, | |
162 | .b[PSC_VOLTAGE_IN] = 0, | |
163 | .R[PSC_VOLTAGE_IN] = 0, | |
164 | .m[PSC_VOLTAGE_OUT] = 2, | |
165 | .b[PSC_VOLTAGE_OUT] = 0, | |
166 | .R[PSC_VOLTAGE_OUT] = 3, | |
167 | .m[PSC_CURRENT_IN] = 1, | |
168 | .b[PSC_CURRENT_IN] = 0, | |
169 | .R[PSC_CURRENT_IN] = 2, | |
170 | .m[PSC_CURRENT_OUT] = 1, | |
171 | .b[PSC_CURRENT_OUT] = 0, | |
172 | .R[PSC_CURRENT_OUT] = 2, | |
173 | .m[PSC_TEMPERATURE] = 1, | |
174 | .b[PSC_TEMPERATURE] = 0, | |
175 | .R[PSC_TEMPERATURE] = 0, | |
176 | .func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_IIN | PMBUS_HAVE_VOUT | | |
177 | PMBUS_HAVE_IOUT | PMBUS_HAVE_TEMP, | |
178 | .read_byte_data = ltc3815_read_byte_data, | |
179 | .read_word_data = ltc3815_read_word_data, | |
180 | .write_byte = ltc3815_write_byte, | |
181 | .write_word_data = ltc3815_write_word_data, | |
182 | }; | |
183 | ||
184 | static int ltc3815_probe(struct i2c_client *client, | |
185 | const struct i2c_device_id *id) | |
186 | { | |
187 | int chip_id; | |
188 | ||
189 | if (!i2c_check_functionality(client->adapter, | |
190 | I2C_FUNC_SMBUS_READ_WORD_DATA)) | |
191 | return -ENODEV; | |
192 | ||
193 | chip_id = i2c_smbus_read_word_data(client, LTC3815_MFR_SPECIAL_ID); | |
194 | if (chip_id < 0) | |
195 | return chip_id; | |
196 | if ((chip_id & LTC3815_ID_MASK) != LTC3815_ID) | |
197 | return -ENODEV; | |
198 | ||
199 | return pmbus_do_probe(client, id, <c3815_info); | |
200 | } | |
201 | ||
202 | static struct i2c_driver ltc3815_driver = { | |
203 | .driver = { | |
204 | .name = "ltc3815", | |
205 | }, | |
206 | .probe = ltc3815_probe, | |
207 | .remove = pmbus_do_remove, | |
208 | .id_table = ltc3815_id, | |
209 | }; | |
210 | ||
211 | module_i2c_driver(ltc3815_driver); | |
212 | ||
213 | MODULE_AUTHOR("Guenter Roeck"); | |
214 | MODULE_DESCRIPTION("PMBus driver for LTC3815"); | |
215 | MODULE_LICENSE("GPL"); |