Andrew Jeffery | 4d420a6 | 2017-11-03 15:53:02 +1100 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2017 IBM Corp. |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify |
| 5 | * it under the terms of the GNU General Public License as published by |
| 6 | * the Free Software Foundation; either version 2 of the License, or |
| 7 | * (at your option) any later version. |
| 8 | */ |
| 9 | |
| 10 | #include <linux/kernel.h> |
| 11 | #include <linux/module.h> |
| 12 | #include <linux/init.h> |
| 13 | #include <linux/err.h> |
| 14 | #include <linux/i2c.h> |
| 15 | #include "pmbus.h" |
| 16 | |
| 17 | enum max31785_regs { |
| 18 | MFR_REVISION = 0x9b, |
Andrew Jeffery | cf583b4 | 2017-11-20 15:12:06 +1030 | [diff] [blame] | 19 | MFR_FAN_CONFIG = 0xf1, |
Andrew Jeffery | 4d420a6 | 2017-11-03 15:53:02 +1100 | [diff] [blame] | 20 | }; |
| 21 | |
Andrew Jeffery | cf583b4 | 2017-11-20 15:12:06 +1030 | [diff] [blame] | 22 | #define MAX31785 0x3030 |
| 23 | #define MAX31785A 0x3040 |
| 24 | |
| 25 | #define MFR_FAN_CONFIG_DUAL_TACH BIT(12) |
| 26 | |
Andrew Jeffery | 4d420a6 | 2017-11-03 15:53:02 +1100 | [diff] [blame] | 27 | #define MAX31785_NR_PAGES 23 |
Andrew Jeffery | cf583b4 | 2017-11-20 15:12:06 +1030 | [diff] [blame] | 28 | #define MAX31785_NR_FAN_PAGES 6 |
| 29 | |
| 30 | static int max31785_read_byte_data(struct i2c_client *client, int page, |
| 31 | int reg) |
| 32 | { |
| 33 | if (page < MAX31785_NR_PAGES) |
| 34 | return -ENODATA; |
| 35 | |
| 36 | switch (reg) { |
| 37 | case PMBUS_VOUT_MODE: |
| 38 | return -ENOTSUPP; |
| 39 | case PMBUS_FAN_CONFIG_12: |
| 40 | return pmbus_read_byte_data(client, page - MAX31785_NR_PAGES, |
| 41 | reg); |
| 42 | } |
| 43 | |
| 44 | return -ENODATA; |
| 45 | } |
| 46 | |
| 47 | static int max31785_write_byte(struct i2c_client *client, int page, u8 value) |
| 48 | { |
| 49 | if (page < MAX31785_NR_PAGES) |
| 50 | return -ENODATA; |
| 51 | |
| 52 | return -ENOTSUPP; |
| 53 | } |
| 54 | |
| 55 | static int max31785_read_long_data(struct i2c_client *client, int page, |
| 56 | int reg, u32 *data) |
| 57 | { |
| 58 | unsigned char cmdbuf[1]; |
| 59 | unsigned char rspbuf[4]; |
| 60 | int rc; |
| 61 | |
| 62 | struct i2c_msg msg[2] = { |
| 63 | { |
| 64 | .addr = client->addr, |
| 65 | .flags = 0, |
| 66 | .len = sizeof(cmdbuf), |
| 67 | .buf = cmdbuf, |
| 68 | }, |
| 69 | { |
| 70 | .addr = client->addr, |
| 71 | .flags = I2C_M_RD, |
| 72 | .len = sizeof(rspbuf), |
| 73 | .buf = rspbuf, |
| 74 | }, |
| 75 | }; |
| 76 | |
| 77 | cmdbuf[0] = reg; |
| 78 | |
| 79 | rc = pmbus_set_page(client, page); |
| 80 | if (rc < 0) |
| 81 | return rc; |
| 82 | |
| 83 | rc = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg)); |
| 84 | if (rc < 0) |
| 85 | return rc; |
| 86 | |
| 87 | *data = (rspbuf[0] << (0 * 8)) | (rspbuf[1] << (1 * 8)) | |
| 88 | (rspbuf[2] << (2 * 8)) | (rspbuf[3] << (3 * 8)); |
| 89 | |
| 90 | return rc; |
| 91 | } |
Andrew Jeffery | 4d420a6 | 2017-11-03 15:53:02 +1100 | [diff] [blame] | 92 | |
Andrew Jeffery | 56ad86b | 2017-11-20 15:12:04 +1030 | [diff] [blame] | 93 | static int max31785_get_pwm(struct i2c_client *client, int page) |
| 94 | { |
| 95 | int rv; |
| 96 | |
| 97 | rv = pmbus_get_fan_rate_device(client, page, 0, percent); |
| 98 | if (rv < 0) |
| 99 | return rv; |
| 100 | else if (rv >= 0x8000) |
| 101 | return 0; |
| 102 | else if (rv >= 0x2711) |
| 103 | return 0x2710; |
| 104 | |
| 105 | return rv; |
| 106 | } |
| 107 | |
| 108 | static int max31785_get_pwm_mode(struct i2c_client *client, int page) |
| 109 | { |
| 110 | int config; |
| 111 | int command; |
| 112 | |
| 113 | config = pmbus_read_byte_data(client, page, PMBUS_FAN_CONFIG_12); |
| 114 | if (config < 0) |
| 115 | return config; |
| 116 | |
| 117 | command = pmbus_read_word_data(client, page, PMBUS_FAN_COMMAND_1); |
| 118 | if (command < 0) |
| 119 | return command; |
| 120 | |
| 121 | if (config & PB_FAN_1_RPM) |
| 122 | return (command >= 0x8000) ? 3 : 2; |
| 123 | |
| 124 | if (command >= 0x8000) |
| 125 | return 3; |
| 126 | else if (command >= 0x2711) |
| 127 | return 0; |
| 128 | |
| 129 | return 1; |
| 130 | } |
| 131 | |
| 132 | static int max31785_read_word_data(struct i2c_client *client, int page, |
| 133 | int reg) |
| 134 | { |
Andrew Jeffery | cf583b4 | 2017-11-20 15:12:06 +1030 | [diff] [blame] | 135 | u32 val; |
Andrew Jeffery | 56ad86b | 2017-11-20 15:12:04 +1030 | [diff] [blame] | 136 | int rv; |
| 137 | |
| 138 | switch (reg) { |
Andrew Jeffery | cf583b4 | 2017-11-20 15:12:06 +1030 | [diff] [blame] | 139 | case PMBUS_READ_FAN_SPEED_1: |
| 140 | if (page < MAX31785_NR_PAGES) |
| 141 | return -ENODATA; |
| 142 | |
| 143 | rv = max31785_read_long_data(client, page - MAX31785_NR_PAGES, |
| 144 | reg, &val); |
| 145 | if (rv < 0) |
| 146 | return rv; |
| 147 | |
| 148 | rv = (val >> 16) & 0xffff; |
| 149 | break; |
| 150 | case PMBUS_FAN_COMMAND_1: |
| 151 | /* |
| 152 | * PMBUS_FAN_COMMAND_x is probed to judge whether or not to |
| 153 | * expose fan control registers. |
| 154 | * |
| 155 | * Don't expose fan_target attribute for virtual pages. |
| 156 | */ |
| 157 | rv = (page >= MAX31785_NR_PAGES) ? -ENOTSUPP : -ENODATA; |
| 158 | break; |
Andrew Jeffery | 56ad86b | 2017-11-20 15:12:04 +1030 | [diff] [blame] | 159 | case PMBUS_VIRT_PWM_1: |
| 160 | rv = max31785_get_pwm(client, page); |
| 161 | break; |
| 162 | case PMBUS_VIRT_PWM_ENABLE_1: |
| 163 | rv = max31785_get_pwm_mode(client, page); |
| 164 | break; |
| 165 | default: |
| 166 | rv = -ENODATA; |
| 167 | break; |
| 168 | } |
| 169 | |
| 170 | return rv; |
| 171 | } |
| 172 | |
| 173 | static inline u32 max31785_scale_pwm(u32 sensor_val) |
| 174 | { |
| 175 | /* |
| 176 | * The datasheet describes the accepted value range for manual PWM as |
| 177 | * [0, 0x2710], while the hwmon pwmX sysfs interface accepts values in |
| 178 | * [0, 255]. The MAX31785 uses DIRECT mode to scale the FAN_COMMAND |
| 179 | * registers and in PWM mode the coefficients are m=1, b=0, R=2. The |
| 180 | * important observation here is that 0x2710 == 10000 == 100 * 100. |
| 181 | * |
| 182 | * R=2 (== 10^2 == 100) accounts for scaling the value provided at the |
| 183 | * sysfs interface into the required hardware resolution, but it does |
| 184 | * not yet yield a value that we can write to the device (this initial |
| 185 | * scaling is handled by pmbus_data2reg()). Multiplying by 100 below |
| 186 | * translates the parameter value into the percentage units required by |
| 187 | * PMBus, and then we scale back by 255 as required by the hwmon pwmX |
| 188 | * interface to yield the percentage value at the appropriate |
| 189 | * resolution for hardware. |
| 190 | */ |
| 191 | return (sensor_val * 100) / 255; |
| 192 | } |
| 193 | |
| 194 | static int max31785_pwm_enable(struct i2c_client *client, int page, |
| 195 | u16 word) |
| 196 | { |
| 197 | int config = 0; |
| 198 | int rate; |
| 199 | |
| 200 | switch (word) { |
| 201 | case 0: |
| 202 | rate = 0x7fff; |
| 203 | break; |
| 204 | case 1: |
| 205 | rate = pmbus_get_fan_rate_cached(client, page, 0, percent); |
| 206 | if (rate < 0) |
| 207 | return rate; |
| 208 | rate = max31785_scale_pwm(rate); |
| 209 | break; |
| 210 | case 2: |
| 211 | config = PB_FAN_1_RPM; |
| 212 | rate = pmbus_get_fan_rate_cached(client, page, 0, rpm); |
| 213 | if (rate < 0) |
| 214 | return rate; |
| 215 | break; |
| 216 | case 3: |
| 217 | rate = 0xffff; |
| 218 | break; |
| 219 | default: |
| 220 | return -EINVAL; |
| 221 | } |
| 222 | |
| 223 | return pmbus_update_fan(client, page, 0, config, PB_FAN_1_RPM, rate); |
| 224 | } |
| 225 | |
| 226 | static int max31785_write_word_data(struct i2c_client *client, int page, |
| 227 | int reg, u16 word) |
| 228 | { |
| 229 | switch (reg) { |
| 230 | case PMBUS_VIRT_PWM_1: |
| 231 | return pmbus_update_fan(client, page, 0, 0, PB_FAN_1_RPM, |
| 232 | max31785_scale_pwm(word)); |
| 233 | case PMBUS_VIRT_PWM_ENABLE_1: |
| 234 | return max31785_pwm_enable(client, page, word); |
| 235 | default: |
| 236 | break; |
| 237 | } |
| 238 | |
| 239 | return -ENODATA; |
| 240 | } |
| 241 | |
Andrew Jeffery | 4d420a6 | 2017-11-03 15:53:02 +1100 | [diff] [blame] | 242 | #define MAX31785_FAN_FUNCS \ |
Andrew Jeffery | 56ad86b | 2017-11-20 15:12:04 +1030 | [diff] [blame] | 243 | (PMBUS_HAVE_FAN12 | PMBUS_HAVE_STATUS_FAN12 | PMBUS_HAVE_PWM12) |
Andrew Jeffery | 4d420a6 | 2017-11-03 15:53:02 +1100 | [diff] [blame] | 244 | |
| 245 | #define MAX31785_TEMP_FUNCS \ |
| 246 | (PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP) |
| 247 | |
| 248 | #define MAX31785_VOUT_FUNCS \ |
| 249 | (PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT) |
| 250 | |
Andrew Jeffery | cf583b4 | 2017-11-20 15:12:06 +1030 | [diff] [blame] | 251 | #define MAX37185_NUM_FAN_PAGES 6 |
| 252 | |
Andrew Jeffery | 4d420a6 | 2017-11-03 15:53:02 +1100 | [diff] [blame] | 253 | static const struct pmbus_driver_info max31785_info = { |
| 254 | .pages = MAX31785_NR_PAGES, |
| 255 | |
Andrew Jeffery | 56ad86b | 2017-11-20 15:12:04 +1030 | [diff] [blame] | 256 | .write_word_data = max31785_write_word_data, |
Andrew Jeffery | cf583b4 | 2017-11-20 15:12:06 +1030 | [diff] [blame] | 257 | .read_byte_data = max31785_read_byte_data, |
Andrew Jeffery | 56ad86b | 2017-11-20 15:12:04 +1030 | [diff] [blame] | 258 | .read_word_data = max31785_read_word_data, |
Andrew Jeffery | cf583b4 | 2017-11-20 15:12:06 +1030 | [diff] [blame] | 259 | .write_byte = max31785_write_byte, |
Andrew Jeffery | 56ad86b | 2017-11-20 15:12:04 +1030 | [diff] [blame] | 260 | |
Andrew Jeffery | 4d420a6 | 2017-11-03 15:53:02 +1100 | [diff] [blame] | 261 | /* RPM */ |
| 262 | .format[PSC_FAN] = direct, |
| 263 | .m[PSC_FAN] = 1, |
| 264 | .b[PSC_FAN] = 0, |
| 265 | .R[PSC_FAN] = 0, |
Andrew Jeffery | 56ad86b | 2017-11-20 15:12:04 +1030 | [diff] [blame] | 266 | /* PWM */ |
| 267 | .format[PSC_PWM] = direct, |
| 268 | .m[PSC_PWM] = 1, |
| 269 | .b[PSC_PWM] = 0, |
| 270 | .R[PSC_PWM] = 2, |
Andrew Jeffery | 4d420a6 | 2017-11-03 15:53:02 +1100 | [diff] [blame] | 271 | .func[0] = MAX31785_FAN_FUNCS, |
| 272 | .func[1] = MAX31785_FAN_FUNCS, |
| 273 | .func[2] = MAX31785_FAN_FUNCS, |
| 274 | .func[3] = MAX31785_FAN_FUNCS, |
| 275 | .func[4] = MAX31785_FAN_FUNCS, |
| 276 | .func[5] = MAX31785_FAN_FUNCS, |
| 277 | |
| 278 | .format[PSC_TEMPERATURE] = direct, |
| 279 | .m[PSC_TEMPERATURE] = 1, |
| 280 | .b[PSC_TEMPERATURE] = 0, |
| 281 | .R[PSC_TEMPERATURE] = 2, |
| 282 | .func[6] = MAX31785_TEMP_FUNCS, |
| 283 | .func[7] = MAX31785_TEMP_FUNCS, |
| 284 | .func[8] = MAX31785_TEMP_FUNCS, |
| 285 | .func[9] = MAX31785_TEMP_FUNCS, |
| 286 | .func[10] = MAX31785_TEMP_FUNCS, |
| 287 | .func[11] = MAX31785_TEMP_FUNCS, |
| 288 | .func[12] = MAX31785_TEMP_FUNCS, |
| 289 | .func[13] = MAX31785_TEMP_FUNCS, |
| 290 | .func[14] = MAX31785_TEMP_FUNCS, |
| 291 | .func[15] = MAX31785_TEMP_FUNCS, |
| 292 | .func[16] = MAX31785_TEMP_FUNCS, |
| 293 | |
| 294 | .format[PSC_VOLTAGE_OUT] = direct, |
| 295 | .m[PSC_VOLTAGE_OUT] = 1, |
| 296 | .b[PSC_VOLTAGE_OUT] = 0, |
| 297 | .R[PSC_VOLTAGE_OUT] = 0, |
| 298 | .func[17] = MAX31785_VOUT_FUNCS, |
| 299 | .func[18] = MAX31785_VOUT_FUNCS, |
| 300 | .func[19] = MAX31785_VOUT_FUNCS, |
| 301 | .func[20] = MAX31785_VOUT_FUNCS, |
| 302 | .func[21] = MAX31785_VOUT_FUNCS, |
| 303 | .func[22] = MAX31785_VOUT_FUNCS, |
| 304 | }; |
| 305 | |
Andrew Jeffery | cf583b4 | 2017-11-20 15:12:06 +1030 | [diff] [blame] | 306 | static int max31785_configure_dual_tach(struct i2c_client *client, |
| 307 | struct pmbus_driver_info *info) |
| 308 | { |
| 309 | int ret; |
| 310 | int i; |
| 311 | |
| 312 | for (i = 0; i < MAX31785_NR_FAN_PAGES; i++) { |
| 313 | ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, i); |
| 314 | if (ret < 0) |
| 315 | return ret; |
| 316 | |
| 317 | ret = i2c_smbus_read_word_data(client, MFR_FAN_CONFIG); |
| 318 | if (ret < 0) |
| 319 | return ret; |
| 320 | |
| 321 | if (ret & MFR_FAN_CONFIG_DUAL_TACH) { |
| 322 | int virtual = MAX31785_NR_PAGES + i; |
| 323 | |
| 324 | info->pages = virtual + 1; |
| 325 | info->func[virtual] |= PMBUS_HAVE_FAN12; |
| 326 | info->func[virtual] |= PMBUS_PAGE_VIRTUAL; |
| 327 | } |
| 328 | } |
| 329 | |
| 330 | return 0; |
| 331 | } |
| 332 | |
Andrew Jeffery | 4d420a6 | 2017-11-03 15:53:02 +1100 | [diff] [blame] | 333 | static int max31785_probe(struct i2c_client *client, |
| 334 | const struct i2c_device_id *id) |
| 335 | { |
| 336 | struct device *dev = &client->dev; |
| 337 | struct pmbus_driver_info *info; |
Andrew Jeffery | cf583b4 | 2017-11-20 15:12:06 +1030 | [diff] [blame] | 338 | bool dual_tach = false; |
Andrew Jeffery | 4d420a6 | 2017-11-03 15:53:02 +1100 | [diff] [blame] | 339 | s64 ret; |
| 340 | |
Andrew Jeffery | cf583b4 | 2017-11-20 15:12:06 +1030 | [diff] [blame] | 341 | if (!i2c_check_functionality(client->adapter, |
| 342 | I2C_FUNC_SMBUS_BYTE_DATA | |
| 343 | I2C_FUNC_SMBUS_WORD_DATA)) |
| 344 | return -ENODEV; |
| 345 | |
Andrew Jeffery | 4d420a6 | 2017-11-03 15:53:02 +1100 | [diff] [blame] | 346 | info = devm_kzalloc(dev, sizeof(struct pmbus_driver_info), GFP_KERNEL); |
| 347 | if (!info) |
| 348 | return -ENOMEM; |
| 349 | |
| 350 | *info = max31785_info; |
| 351 | |
| 352 | ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, 255); |
| 353 | if (ret < 0) |
| 354 | return ret; |
| 355 | |
Andrew Jeffery | cf583b4 | 2017-11-20 15:12:06 +1030 | [diff] [blame] | 356 | ret = i2c_smbus_read_word_data(client, MFR_REVISION); |
| 357 | if (ret < 0) |
| 358 | return ret; |
| 359 | |
| 360 | if (ret == MAX31785A) { |
| 361 | dual_tach = true; |
| 362 | } else if (ret == MAX31785) { |
| 363 | if (!strcmp("max31785a", id->name)) |
| 364 | dev_warn(dev, "Expected max3175a, found max31785: cannot provide secondary tachometer readings\n"); |
| 365 | } else { |
| 366 | return -ENODEV; |
| 367 | } |
| 368 | |
| 369 | if (dual_tach) { |
| 370 | ret = max31785_configure_dual_tach(client, info); |
| 371 | if (ret < 0) |
| 372 | return ret; |
| 373 | } |
| 374 | |
Andrew Jeffery | 4d420a6 | 2017-11-03 15:53:02 +1100 | [diff] [blame] | 375 | return pmbus_do_probe(client, id, info); |
| 376 | } |
| 377 | |
| 378 | static const struct i2c_device_id max31785_id[] = { |
| 379 | { "max31785", 0 }, |
| 380 | { "max31785a", 0 }, |
| 381 | { }, |
| 382 | }; |
| 383 | |
| 384 | MODULE_DEVICE_TABLE(i2c, max31785_id); |
| 385 | |
Javier Martinez Canillas | 98b16a0 | 2017-11-30 19:12:57 +0100 | [diff] [blame] | 386 | static const struct of_device_id max31785_of_match[] = { |
| 387 | { .compatible = "maxim,max31785" }, |
| 388 | { .compatible = "maxim,max31785a" }, |
| 389 | { }, |
| 390 | }; |
| 391 | |
| 392 | MODULE_DEVICE_TABLE(of, max31785_of_match); |
| 393 | |
Andrew Jeffery | 4d420a6 | 2017-11-03 15:53:02 +1100 | [diff] [blame] | 394 | static struct i2c_driver max31785_driver = { |
| 395 | .driver = { |
| 396 | .name = "max31785", |
Javier Martinez Canillas | 98b16a0 | 2017-11-30 19:12:57 +0100 | [diff] [blame] | 397 | .of_match_table = max31785_of_match, |
Andrew Jeffery | 4d420a6 | 2017-11-03 15:53:02 +1100 | [diff] [blame] | 398 | }, |
| 399 | .probe = max31785_probe, |
| 400 | .remove = pmbus_do_remove, |
| 401 | .id_table = max31785_id, |
| 402 | }; |
| 403 | |
| 404 | module_i2c_driver(max31785_driver); |
| 405 | |
| 406 | MODULE_AUTHOR("Andrew Jeffery <andrew@aj.id.au>"); |
| 407 | MODULE_DESCRIPTION("PMBus driver for the Maxim MAX31785"); |
| 408 | MODULE_LICENSE("GPL"); |