1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Hardware monitoring driver for FSP 3Y-Power PSUs 4 * 5 * Copyright (c) 2021 Václav Kubernát, CESNET 6 * 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. 12 */ 13 14 #include <linux/delay.h> 15 #include <linux/i2c.h> 16 #include <linux/kernel.h> 17 #include <linux/module.h> 18 #include "pmbus.h" 19 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 30 31 enum chips { 32 ym2151e, 33 yh5151e 34 }; 35 36 struct fsp3y_data { 37 struct pmbus_driver_info info; 38 int chip; 39 int page; 40 41 bool vout_linear_11; 42 }; 43 44 #define to_fsp3y_data(x) container_of(x, struct fsp3y_data, info) 45 46 static int page_log_to_page_real(int page_log, enum chips chip) 47 { 48 switch (chip) { 49 case ym2151e: 50 switch (page_log) { 51 case YM2151_PAGE_12V_LOG: 52 return YM2151_PAGE_12V_REAL; 53 case YM2151_PAGE_5VSB_LOG: 54 return YM2151_PAGE_5VSB_REAL; 55 } 56 return -EINVAL; 57 case yh5151e: 58 switch (page_log) { 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; 65 } 66 return -EINVAL; 67 } 68 69 return -EINVAL; 70 } 71 72 static int set_page(struct i2c_client *client, int page_log) 73 { 74 const struct pmbus_driver_info *info = pmbus_get_driver_info(client); 75 struct fsp3y_data *data = to_fsp3y_data(info); 76 int rv; 77 int page_real; 78 79 if (page_log < 0) 80 return 0; 81 82 page_real = page_log_to_page_real(page_log, data->chip); 83 if (page_real < 0) 84 return page_real; 85 86 if (data->page != page_real) { 87 rv = i2c_smbus_write_byte_data(client, PMBUS_PAGE, page_real); 88 if (rv < 0) 89 return rv; 90 91 data->page = page_real; 92 93 /* 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 98 * enough). 99 */ 100 usleep_range(20000, 30000); 101 } 102 103 return 0; 104 } 105 106 static int fsp3y_read_byte_data(struct i2c_client *client, int page, int reg) 107 { 108 const struct pmbus_driver_info *info = pmbus_get_driver_info(client); 109 struct fsp3y_data *data = to_fsp3y_data(info); 110 int rv; 111 112 /* 113 * Inject an exponent for non-compliant YH5151-E. 114 */ 115 if (data->vout_linear_11 && reg == PMBUS_VOUT_MODE) 116 return 0x1A; 117 118 rv = set_page(client, page); 119 if (rv < 0) 120 return rv; 121 122 return i2c_smbus_read_byte_data(client, reg); 123 } 124 125 static int fsp3y_read_word_data(struct i2c_client *client, int page, int phase, int reg) 126 { 127 const struct pmbus_driver_info *info = pmbus_get_driver_info(client); 128 struct fsp3y_data *data = to_fsp3y_data(info); 129 int rv; 130 131 /* 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. 137 */ 138 switch (reg) { 139 case PMBUS_READ_FAN_SPEED_1: 140 case PMBUS_READ_IIN: 141 case PMBUS_READ_IOUT: 142 case PMBUS_READ_PIN: 143 case PMBUS_READ_POUT: 144 case PMBUS_READ_TEMPERATURE_1: 145 case PMBUS_READ_TEMPERATURE_2: 146 case PMBUS_READ_TEMPERATURE_3: 147 case PMBUS_READ_VIN: 148 case PMBUS_READ_VOUT: 149 case PMBUS_STATUS_WORD: 150 break; 151 default: 152 return -ENXIO; 153 } 154 155 rv = set_page(client, page); 156 if (rv < 0) 157 return rv; 158 159 rv = i2c_smbus_read_word_data(client, reg); 160 if (rv < 0) 161 return rv; 162 163 /* 164 * Handle YH-5151E non-compliant linear11 vout voltage. 165 */ 166 if (data->vout_linear_11 && reg == PMBUS_READ_VOUT) 167 rv = sign_extend32(rv, 10) & 0xffff; 168 169 return rv; 170 } 171 172 static struct pmbus_driver_info fsp3y_info[] = { 173 [ym2151e] = { 174 .pages = 2, 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 | 180 PMBUS_HAVE_FAN12, 181 .func[YM2151_PAGE_5VSB_LOG] = 182 PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT, 183 PMBUS_HAVE_IIN, 184 .read_word_data = fsp3y_read_word_data, 185 .read_byte_data = fsp3y_read_byte_data, 186 }, 187 [yh5151e] = { 188 .pages = 3, 189 .func[YH5151E_PAGE_12V_LOG] = 190 PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT | 191 PMBUS_HAVE_POUT | 192 PMBUS_HAVE_TEMP | PMBUS_HAVE_TEMP2 | PMBUS_HAVE_TEMP3, 193 .func[YH5151E_PAGE_5V_LOG] = 194 PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT | 195 PMBUS_HAVE_POUT, 196 .func[YH5151E_PAGE_3V3_LOG] = 197 PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT | 198 PMBUS_HAVE_POUT, 199 .read_word_data = fsp3y_read_word_data, 200 .read_byte_data = fsp3y_read_byte_data, 201 } 202 }; 203 204 static int fsp3y_detect(struct i2c_client *client) 205 { 206 int rv; 207 u8 buf[I2C_SMBUS_BLOCK_MAX + 1]; 208 209 rv = i2c_smbus_read_block_data(client, PMBUS_MFR_MODEL, buf); 210 if (rv < 0) 211 return rv; 212 213 buf[rv] = '\0'; 214 215 if (rv == 8) { 216 if (!strcmp(buf, "YM-2151E")) 217 return ym2151e; 218 else if (!strcmp(buf, "YH-5151E")) 219 return yh5151e; 220 } 221 222 dev_err(&client->dev, "Unsupported model %.*s\n", rv, buf); 223 return -ENODEV; 224 } 225 226 static const struct i2c_device_id fsp3y_id[] = { 227 {"ym2151e", ym2151e}, 228 {"yh5151e", yh5151e}, 229 { } 230 }; 231 232 static int fsp3y_probe(struct i2c_client *client) 233 { 234 struct fsp3y_data *data; 235 const struct i2c_device_id *id; 236 int rv; 237 238 data = devm_kzalloc(&client->dev, sizeof(struct fsp3y_data), GFP_KERNEL); 239 if (!data) 240 return -ENOMEM; 241 242 data->chip = fsp3y_detect(client); 243 if (data->chip < 0) 244 return data->chip; 245 246 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); 250 251 rv = i2c_smbus_read_byte_data(client, PMBUS_PAGE); 252 if (rv < 0) 253 return rv; 254 data->page = rv; 255 256 data->info = fsp3y_info[data->chip]; 257 258 /* 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. 262 * 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. 266 */ 267 data->vout_linear_11 = false; 268 if (data->chip == yh5151e) { 269 rv = i2c_smbus_read_byte_data(client, PMBUS_VOUT_MODE); 270 if (rv < 0) 271 return rv; 272 273 if (rv == 0xFF) 274 data->vout_linear_11 = true; 275 } 276 277 return pmbus_do_probe(client, &data->info); 278 } 279 280 MODULE_DEVICE_TABLE(i2c, fsp3y_id); 281 282 static struct i2c_driver fsp3y_driver = { 283 .driver = { 284 .name = "fsp3y", 285 }, 286 .probe_new = fsp3y_probe, 287 .id_table = fsp3y_id 288 }; 289 290 module_i2c_driver(fsp3y_driver); 291 292 MODULE_AUTHOR("Václav Kubernát"); 293 MODULE_DESCRIPTION("PMBus driver for FSP/3Y-Power power supplies"); 294 MODULE_LICENSE("GPL"); 295 MODULE_IMPORT_NS(PMBUS); 296