1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Hardware monitoring driver for FSP 3Y-Power PSUs
5 * Copyright (c) 2021 Václav Kubernát, CESNET
7 * This driver is mostly reverse engineered with the help of a tool called pmbus_peek written by
8 * David Brownell (and later adopted by Jan Kundrát). The device has some sort of a timing issue
9 * when switching pages, details are explained in the code. The driver support is limited. It
10 * exposes only the values, that have been tested to work correctly. Unsupported values either
11 * aren't supported by the devices or their encondings are unknown.
14 #include <linux/delay.h>
15 #include <linux/i2c.h>
16 #include <linux/kernel.h>
17 #include <linux/module.h>
20 #define YM2151_PAGE_12V_LOG 0x00
21 #define YM2151_PAGE_12V_REAL 0x00
22 #define YM2151_PAGE_5VSB_LOG 0x01
23 #define YM2151_PAGE_5VSB_REAL 0x20
24 #define YH5151E_PAGE_12V_LOG 0x00
25 #define YH5151E_PAGE_12V_REAL 0x00
26 #define YH5151E_PAGE_5V_LOG 0x01
27 #define YH5151E_PAGE_5V_REAL 0x10
28 #define YH5151E_PAGE_3V3_LOG 0x02
29 #define YH5151E_PAGE_3V3_REAL 0x11
37 struct pmbus_driver_info info;
44 #define to_fsp3y_data(x) container_of(x, struct fsp3y_data, info)
46 static int page_log_to_page_real(int page_log, enum chips chip)
51 case YM2151_PAGE_12V_LOG:
52 return YM2151_PAGE_12V_REAL;
53 case YM2151_PAGE_5VSB_LOG:
54 return YM2151_PAGE_5VSB_REAL;
59 case YH5151E_PAGE_12V_LOG:
60 return YH5151E_PAGE_12V_REAL;
61 case YH5151E_PAGE_5V_LOG:
62 return YH5151E_PAGE_5V_REAL;
63 case YH5151E_PAGE_3V3_LOG:
64 return YH5151E_PAGE_3V3_REAL;
72 static int set_page(struct i2c_client *client, int page_log)
74 const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
75 struct fsp3y_data *data = to_fsp3y_data(info);
82 page_real = page_log_to_page_real(page_log, data->chip);
86 if (data->page != page_real) {
87 rv = i2c_smbus_write_byte_data(client, PMBUS_PAGE, page_real);
91 data->page = page_real;
94 * Testing showed that the device has a timing issue. After
95 * setting a page, it takes a while, before the device actually
96 * gives the correct values from the correct page. 20 ms was
97 * tested to be enough to not give wrong values (15 ms wasn't
100 usleep_range(20000, 30000);
106 static int fsp3y_read_byte_data(struct i2c_client *client, int page, int reg)
108 const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
109 struct fsp3y_data *data = to_fsp3y_data(info);
113 * Inject an exponent for non-compliant YH5151-E.
115 if (data->vout_linear_11 && reg == PMBUS_VOUT_MODE)
118 rv = set_page(client, page);
122 return i2c_smbus_read_byte_data(client, reg);
125 static int fsp3y_read_word_data(struct i2c_client *client, int page, int phase, int reg)
127 const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
128 struct fsp3y_data *data = to_fsp3y_data(info);
132 * This masks commands which weren't tested to work correctly. Some of
133 * the masked commands return 0xFFFF. These would probably get tagged as
134 * invalid by pmbus_core. Other ones do return values which might be
135 * useful (that is, they are not 0xFFFF), but their encoding is unknown,
136 * and so they are unsupported.
139 case PMBUS_READ_FAN_SPEED_1:
141 case PMBUS_READ_IOUT:
143 case PMBUS_READ_POUT:
144 case PMBUS_READ_TEMPERATURE_1:
145 case PMBUS_READ_TEMPERATURE_2:
146 case PMBUS_READ_TEMPERATURE_3:
148 case PMBUS_READ_VOUT:
149 case PMBUS_STATUS_WORD:
155 rv = set_page(client, page);
159 rv = i2c_smbus_read_word_data(client, reg);
164 * Handle YH-5151E non-compliant linear11 vout voltage.
166 if (data->vout_linear_11 && reg == PMBUS_READ_VOUT)
167 rv = sign_extend32(rv, 10) & 0xffff;
172 static struct pmbus_driver_info fsp3y_info[] = {
175 .func[YM2151_PAGE_12V_LOG] =
176 PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT |
177 PMBUS_HAVE_PIN | PMBUS_HAVE_POUT |
178 PMBUS_HAVE_TEMP | PMBUS_HAVE_TEMP2 |
179 PMBUS_HAVE_VIN | PMBUS_HAVE_IIN |
181 .func[YM2151_PAGE_5VSB_LOG] =
182 PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT,
184 .read_word_data = fsp3y_read_word_data,
185 .read_byte_data = fsp3y_read_byte_data,
189 .func[YH5151E_PAGE_12V_LOG] =
190 PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT |
192 PMBUS_HAVE_TEMP | PMBUS_HAVE_TEMP2 | PMBUS_HAVE_TEMP3,
193 .func[YH5151E_PAGE_5V_LOG] =
194 PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT |
196 .func[YH5151E_PAGE_3V3_LOG] =
197 PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT |
199 .read_word_data = fsp3y_read_word_data,
200 .read_byte_data = fsp3y_read_byte_data,
204 static int fsp3y_detect(struct i2c_client *client)
207 u8 buf[I2C_SMBUS_BLOCK_MAX + 1];
209 rv = i2c_smbus_read_block_data(client, PMBUS_MFR_MODEL, buf);
216 if (!strcmp(buf, "YM-2151E"))
218 else if (!strcmp(buf, "YH-5151E"))
222 dev_err(&client->dev, "Unsupported model %.*s\n", rv, buf);
226 static const struct i2c_device_id fsp3y_id[] = {
227 {"ym2151e", ym2151e},
228 {"yh5151e", yh5151e},
232 static int fsp3y_probe(struct i2c_client *client)
234 struct fsp3y_data *data;
235 const struct i2c_device_id *id;
238 data = devm_kzalloc(&client->dev, sizeof(struct fsp3y_data), GFP_KERNEL);
242 data->chip = fsp3y_detect(client);
246 id = i2c_match_id(fsp3y_id, client);
247 if (data->chip != id->driver_data)
248 dev_warn(&client->dev, "Device mismatch: Configured %s (%d), detected %d\n",
249 id->name, (int)id->driver_data, data->chip);
251 rv = i2c_smbus_read_byte_data(client, PMBUS_PAGE);
256 data->info = fsp3y_info[data->chip];
259 * YH-5151E sometimes reports vout in linear11 and sometimes in
260 * linear16. This depends on the exact individual piece of hardware. One
261 * YH-5151E can use linear16 and another might use linear11 instead.
263 * The format can be recognized by reading VOUT_MODE - if it doesn't
264 * report a valid exponent, then vout uses linear11. Otherwise, the
265 * device is compliant and uses linear16.
267 data->vout_linear_11 = false;
268 if (data->chip == yh5151e) {
269 rv = i2c_smbus_read_byte_data(client, PMBUS_VOUT_MODE);
274 data->vout_linear_11 = true;
277 return pmbus_do_probe(client, &data->info);
280 MODULE_DEVICE_TABLE(i2c, fsp3y_id);
282 static struct i2c_driver fsp3y_driver = {
286 .probe_new = fsp3y_probe,
290 module_i2c_driver(fsp3y_driver);
292 MODULE_AUTHOR("Václav Kubernát");
293 MODULE_DESCRIPTION("PMBus driver for FSP/3Y-Power power supplies");
294 MODULE_LICENSE("GPL");
295 MODULE_IMPORT_NS(PMBUS);