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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Hardware monitoring driver for FSP 3Y-Power PSUs4 *5 * Copyright (c) 2021 Václav Kubernát, CESNET6 *7 * This driver is mostly reverse engineered with the help of a tool called pmbus_peek written by8 * David Brownell (and later adopted by Jan Kundrát). The device has some sort of a timing issue9 * when switching pages, details are explained in the code. The driver support is limited. It10 * exposes only the values, that have been tested to work correctly. Unsupported values either11 * 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 0x0021#define YM2151_PAGE_12V_REAL 0x0022#define YM2151_PAGE_5VSB_LOG 0x0123#define YM2151_PAGE_5VSB_REAL 0x2024#define YH5151E_PAGE_12V_LOG 0x0025#define YH5151E_PAGE_12V_REAL 0x0026#define YH5151E_PAGE_5V_LOG 0x0127#define YH5151E_PAGE_5V_REAL 0x1028#define YH5151E_PAGE_3V3_LOG 0x0229#define YH5151E_PAGE_3V3_REAL 0x1130 31enum chips {32 ym2151e,33 yh5151e34};35 36struct 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 46static 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 72static 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. After95 * setting a page, it takes a while, before the device actually96 * gives the correct values from the correct page. 20 ms was97 * tested to be enough to not give wrong values (15 ms wasn't98 * enough).99 */100 usleep_range(20000, 30000);101 }102 103 return 0;104}105 106static 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 125static 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 of133 * the masked commands return 0xFFFF. These would probably get tagged as134 * invalid by pmbus_core. Other ones do return values which might be135 * 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 172static 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 .read_word_data = fsp3y_read_word_data,184 .read_byte_data = fsp3y_read_byte_data,185 },186 [yh5151e] = {187 .pages = 3,188 .func[YH5151E_PAGE_12V_LOG] =189 PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT |190 PMBUS_HAVE_POUT |191 PMBUS_HAVE_TEMP | PMBUS_HAVE_TEMP2 | PMBUS_HAVE_TEMP3,192 .func[YH5151E_PAGE_5V_LOG] =193 PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT |194 PMBUS_HAVE_POUT,195 .func[YH5151E_PAGE_3V3_LOG] =196 PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT |197 PMBUS_HAVE_POUT,198 .read_word_data = fsp3y_read_word_data,199 .read_byte_data = fsp3y_read_byte_data,200 }201};202 203static int fsp3y_detect(struct i2c_client *client)204{205 int rv;206 u8 buf[I2C_SMBUS_BLOCK_MAX + 1];207 208 rv = i2c_smbus_read_block_data(client, PMBUS_MFR_MODEL, buf);209 if (rv < 0)210 return rv;211 212 buf[rv] = '\0';213 214 if (rv == 8) {215 if (!strcmp(buf, "YM-2151E"))216 return ym2151e;217 else if (!strcmp(buf, "YH-5151E"))218 return yh5151e;219 }220 221 dev_err(&client->dev, "Unsupported model %.*s\n", rv, buf);222 return -ENODEV;223}224 225static const struct i2c_device_id fsp3y_id[] = {226 {"ym2151e", ym2151e},227 {"yh5151e", yh5151e},228 { }229};230 231static int fsp3y_probe(struct i2c_client *client)232{233 struct fsp3y_data *data;234 const struct i2c_device_id *id;235 int rv;236 237 data = devm_kzalloc(&client->dev, sizeof(struct fsp3y_data), GFP_KERNEL);238 if (!data)239 return -ENOMEM;240 241 data->chip = fsp3y_detect(client);242 if (data->chip < 0)243 return data->chip;244 245 id = i2c_match_id(fsp3y_id, client);246 if (data->chip != id->driver_data)247 dev_warn(&client->dev, "Device mismatch: Configured %s (%d), detected %d\n",248 id->name, (int)id->driver_data, data->chip);249 250 rv = i2c_smbus_read_byte_data(client, PMBUS_PAGE);251 if (rv < 0)252 return rv;253 data->page = rv;254 255 data->info = fsp3y_info[data->chip];256 257 /*258 * YH-5151E sometimes reports vout in linear11 and sometimes in259 * linear16. This depends on the exact individual piece of hardware. One260 * YH-5151E can use linear16 and another might use linear11 instead.261 *262 * The format can be recognized by reading VOUT_MODE - if it doesn't263 * report a valid exponent, then vout uses linear11. Otherwise, the264 * device is compliant and uses linear16.265 */266 data->vout_linear_11 = false;267 if (data->chip == yh5151e) {268 rv = i2c_smbus_read_byte_data(client, PMBUS_VOUT_MODE);269 if (rv < 0)270 return rv;271 272 if (rv == 0xFF)273 data->vout_linear_11 = true;274 }275 276 return pmbus_do_probe(client, &data->info);277}278 279MODULE_DEVICE_TABLE(i2c, fsp3y_id);280 281static struct i2c_driver fsp3y_driver = {282 .driver = {283 .name = "fsp3y",284 },285 .probe = fsp3y_probe,286 .id_table = fsp3y_id287};288 289module_i2c_driver(fsp3y_driver);290 291MODULE_AUTHOR("Václav Kubernát");292MODULE_DESCRIPTION("PMBus driver for FSP/3Y-Power power supplies");293MODULE_LICENSE("GPL");294MODULE_IMPORT_NS(PMBUS);295