1 /* 2 * g762 - Driver for the Global Mixed-mode Technology Inc. fan speed 3 * PWM controller chips from G762 family, i.e. G762 and G763 4 * 5 * Copyright (C) 2013, Arnaud EBALARD <arno@natisbad.org> 6 * 7 * This work is based on a basic version for 2.6.31 kernel developed 8 * by Olivier Mouchet for LaCie. Updates and correction have been 9 * performed to run on recent kernels. Additional features, like the 10 * ability to configure various characteristics via .dts file or 11 * board init file have been added. Detailed datasheet on which this 12 * development is based is available here: 13 * 14 * http://natisbad.org/NAS/refs/GMT_EDS-762_763-080710-0.2.pdf 15 * 16 * Headers from previous developments have been kept below: 17 * 18 * Copyright (c) 2009 LaCie 19 * 20 * Author: Olivier Mouchet <olivier.mouchet@gmail.com> 21 * 22 * based on g760a code written by Herbert Valerio Riedel <hvr@gnu.org> 23 * Copyright (C) 2007 Herbert Valerio Riedel <hvr@gnu.org> 24 * 25 * g762: minimal datasheet available at: 26 * http://www.gmt.com.tw/product/datasheet/EDS-762_3.pdf 27 * 28 * This program is free software; you can redistribute it and/or modify 29 * it under the terms of the GNU General Public License as published by 30 * the Free Software Foundation; either version 2 of the License, or 31 * (at your option) any later version. 32 * 33 * This program is distributed in the hope that it will be useful, 34 * but WITHOUT ANY WARRANTY; without even the implied warranty of 35 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 36 * GNU General Public License for more details. 37 * 38 * You should have received a copy of the GNU General Public License 39 * along with this program; if not, write to the Free Software 40 * Foundation. 41 */ 42 43 #include <linux/device.h> 44 #include <linux/module.h> 45 #include <linux/init.h> 46 #include <linux/jiffies.h> 47 #include <linux/i2c.h> 48 #include <linux/hwmon.h> 49 #include <linux/hwmon-sysfs.h> 50 #include <linux/err.h> 51 #include <linux/mutex.h> 52 #include <linux/kernel.h> 53 #include <linux/clk.h> 54 #include <linux/of.h> 55 #include <linux/of_device.h> 56 #include <linux/platform_data/g762.h> 57 58 #define DRVNAME "g762" 59 60 static const struct i2c_device_id g762_id[] = { 61 { "g762", 0 }, 62 { "g763", 0 }, 63 { } 64 }; 65 MODULE_DEVICE_TABLE(i2c, g762_id); 66 67 enum g762_regs { 68 G762_REG_SET_CNT = 0x00, 69 G762_REG_ACT_CNT = 0x01, 70 G762_REG_FAN_STA = 0x02, 71 G762_REG_SET_OUT = 0x03, 72 G762_REG_FAN_CMD1 = 0x04, 73 G762_REG_FAN_CMD2 = 0x05, 74 }; 75 76 /* Config register bits */ 77 #define G762_REG_FAN_CMD1_DET_FAN_FAIL 0x80 /* enable fan_fail signal */ 78 #define G762_REG_FAN_CMD1_DET_FAN_OOC 0x40 /* enable fan_out_of_control */ 79 #define G762_REG_FAN_CMD1_OUT_MODE 0x20 /* out mode: PWM or DC */ 80 #define G762_REG_FAN_CMD1_FAN_MODE 0x10 /* fan mode: closed/open-loop */ 81 #define G762_REG_FAN_CMD1_CLK_DIV_ID1 0x08 /* clock divisor value */ 82 #define G762_REG_FAN_CMD1_CLK_DIV_ID0 0x04 83 #define G762_REG_FAN_CMD1_PWM_POLARITY 0x02 /* PWM polarity */ 84 #define G762_REG_FAN_CMD1_PULSE_PER_REV 0x01 /* pulse per fan revolution */ 85 86 #define G762_REG_FAN_CMD2_GEAR_MODE_1 0x08 /* fan gear mode */ 87 #define G762_REG_FAN_CMD2_GEAR_MODE_0 0x04 88 #define G762_REG_FAN_CMD2_FAN_STARTV_1 0x02 /* fan startup voltage */ 89 #define G762_REG_FAN_CMD2_FAN_STARTV_0 0x01 90 91 #define G762_REG_FAN_STA_FAIL 0x02 /* fan fail */ 92 #define G762_REG_FAN_STA_OOC 0x01 /* fan out of control */ 93 94 /* Config register values */ 95 #define G762_OUT_MODE_PWM 1 96 #define G762_OUT_MODE_DC 0 97 98 #define G762_FAN_MODE_CLOSED_LOOP 2 99 #define G762_FAN_MODE_OPEN_LOOP 1 100 101 #define G762_PWM_POLARITY_NEGATIVE 1 102 #define G762_PWM_POLARITY_POSITIVE 0 103 104 /* Register data is read (and cached) at most once per second. */ 105 #define G762_UPDATE_INTERVAL HZ 106 107 /* 108 * Extract pulse count per fan revolution value (2 or 4) from given 109 * FAN_CMD1 register value. 110 */ 111 #define G762_PULSE_FROM_REG(reg) \ 112 ((((reg) & G762_REG_FAN_CMD1_PULSE_PER_REV) + 1) << 1) 113 114 /* 115 * Extract fan clock divisor (1, 2, 4 or 8) from given FAN_CMD1 116 * register value. 117 */ 118 #define G762_CLKDIV_FROM_REG(reg) \ 119 (1 << (((reg) & (G762_REG_FAN_CMD1_CLK_DIV_ID0 | \ 120 G762_REG_FAN_CMD1_CLK_DIV_ID1)) >> 2)) 121 122 /* 123 * Extract fan gear mode multiplier value (0, 2 or 4) from given 124 * FAN_CMD2 register value. 125 */ 126 #define G762_GEARMULT_FROM_REG(reg) \ 127 (1 << (((reg) & (G762_REG_FAN_CMD2_GEAR_MODE_0 | \ 128 G762_REG_FAN_CMD2_GEAR_MODE_1)) >> 2)) 129 130 struct g762_data { 131 struct i2c_client *client; 132 struct device *hwmon_dev; 133 struct clk *clk; 134 135 /* update mutex */ 136 struct mutex update_lock; 137 138 /* board specific parameters. */ 139 u32 clk_freq; 140 141 /* g762 register cache */ 142 bool valid; 143 unsigned long last_updated; /* in jiffies */ 144 145 u8 set_cnt; /* controls fan rotation speed in closed-loop mode */ 146 u8 act_cnt; /* provides access to current fan RPM value */ 147 u8 fan_sta; /* bit 0: set when actual fan speed is more than 148 * 25% outside requested fan speed 149 * bit 1: set when no transition occurs on fan 150 * pin for 0.7s 151 */ 152 u8 set_out; /* controls fan rotation speed in open-loop mode */ 153 u8 fan_cmd1; /* 0: FG_PLS_ID0 FG pulses count per revolution 154 * 0: 2 counts per revolution 155 * 1: 4 counts per revolution 156 * 1: PWM_POLARITY 1: negative_duty 157 * 0: positive_duty 158 * 2,3: [FG_CLOCK_ID0, FG_CLK_ID1] 159 * 00: Divide fan clock by 1 160 * 01: Divide fan clock by 2 161 * 10: Divide fan clock by 4 162 * 11: Divide fan clock by 8 163 * 4: FAN_MODE 1:closed-loop, 0:open-loop 164 * 5: OUT_MODE 1:PWM, 0:DC 165 * 6: DET_FAN_OOC enable "fan ooc" status 166 * 7: DET_FAN_FAIL enable "fan fail" status 167 */ 168 u8 fan_cmd2; /* 0,1: FAN_STARTV 0,1,2,3 -> 0,32,64,96 dac_code 169 * 2,3: FG_GEAR_MODE 170 * 00: multiplier = 1 171 * 01: multiplier = 2 172 * 10: multiplier = 4 173 * 4: Mask ALERT# (g763 only) 174 */ 175 }; 176 177 /* 178 * Convert count value from fan controller register (FAN_SET_CNT) into fan 179 * speed RPM value. Note that the datasheet documents a basic formula; 180 * influence of additional parameters (fan clock divisor, fan gear mode) 181 * have been infered from examples in the datasheet and tests. 182 */ 183 static inline unsigned int rpm_from_cnt(u8 cnt, u32 clk_freq, u16 p, 184 u8 clk_div, u8 gear_mult) 185 { 186 if (cnt == 0xff) /* setting cnt to 255 stops the fan */ 187 return 0; 188 189 return (clk_freq * 30 * gear_mult) / ((cnt ? cnt : 1) * p * clk_div); 190 } 191 192 /* 193 * Convert fan RPM value from sysfs into count value for fan controller 194 * register (FAN_SET_CNT). 195 */ 196 static inline unsigned char cnt_from_rpm(u32 rpm, u32 clk_freq, u16 p, 197 u8 clk_div, u8 gear_mult) 198 { 199 if (!rpm) /* to stop the fan, set cnt to 255 */ 200 return 0xff; 201 202 return clamp_val(((clk_freq * 30 * gear_mult) / (rpm * p * clk_div)), 203 0, 255); 204 } 205 206 /* helper to grab and cache data, at most one time per second */ 207 static struct g762_data *g762_update_client(struct device *dev) 208 { 209 struct i2c_client *client = to_i2c_client(dev); 210 struct g762_data *data = i2c_get_clientdata(client); 211 int ret = 0; 212 213 mutex_lock(&data->update_lock); 214 if (time_before(jiffies, data->last_updated + G762_UPDATE_INTERVAL) && 215 likely(data->valid)) 216 goto out; 217 218 ret = i2c_smbus_read_byte_data(client, G762_REG_SET_CNT); 219 if (ret < 0) 220 goto out; 221 data->set_cnt = ret; 222 223 ret = i2c_smbus_read_byte_data(client, G762_REG_ACT_CNT); 224 if (ret < 0) 225 goto out; 226 data->act_cnt = ret; 227 228 ret = i2c_smbus_read_byte_data(client, G762_REG_FAN_STA); 229 if (ret < 0) 230 goto out; 231 data->fan_sta = ret; 232 233 ret = i2c_smbus_read_byte_data(client, G762_REG_SET_OUT); 234 if (ret < 0) 235 goto out; 236 data->set_out = ret; 237 238 ret = i2c_smbus_read_byte_data(client, G762_REG_FAN_CMD1); 239 if (ret < 0) 240 goto out; 241 data->fan_cmd1 = ret; 242 243 ret = i2c_smbus_read_byte_data(client, G762_REG_FAN_CMD2); 244 if (ret < 0) 245 goto out; 246 data->fan_cmd2 = ret; 247 248 data->last_updated = jiffies; 249 data->valid = true; 250 out: 251 mutex_unlock(&data->update_lock); 252 253 if (ret < 0) /* upon error, encode it in return value */ 254 data = ERR_PTR(ret); 255 256 return data; 257 } 258 259 /* helpers for writing hardware parameters */ 260 261 /* 262 * Set input clock frequency received on CLK pin of the chip. Accepted values 263 * are between 0 and 0xffffff. If zero is given, then default frequency 264 * (32,768Hz) is used. Note that clock frequency is a characteristic of the 265 * system but an internal parameter, i.e. value is not passed to the device. 266 */ 267 static int do_set_clk_freq(struct device *dev, unsigned long val) 268 { 269 struct i2c_client *client = to_i2c_client(dev); 270 struct g762_data *data = i2c_get_clientdata(client); 271 272 if (val > 0xffffff) 273 return -EINVAL; 274 if (!val) 275 val = 32768; 276 277 data->clk_freq = val; 278 279 return 0; 280 } 281 282 /* Set pwm mode. Accepts either 0 (PWM mode) or 1 (DC mode) */ 283 static int do_set_pwm_mode(struct device *dev, unsigned long val) 284 { 285 struct i2c_client *client = to_i2c_client(dev); 286 struct g762_data *data = g762_update_client(dev); 287 int ret; 288 289 if (IS_ERR(data)) 290 return PTR_ERR(data); 291 292 mutex_lock(&data->update_lock); 293 switch (val) { 294 case G762_OUT_MODE_PWM: 295 data->fan_cmd1 |= G762_REG_FAN_CMD1_OUT_MODE; 296 break; 297 case G762_OUT_MODE_DC: 298 data->fan_cmd1 &= ~G762_REG_FAN_CMD1_OUT_MODE; 299 break; 300 default: 301 ret = -EINVAL; 302 goto out; 303 } 304 ret = i2c_smbus_write_byte_data(client, G762_REG_FAN_CMD1, 305 data->fan_cmd1); 306 data->valid = false; 307 out: 308 mutex_unlock(&data->update_lock); 309 310 return ret; 311 } 312 313 /* Set fan clock divisor. Accepts either 1, 2, 4 or 8. */ 314 static int do_set_fan_div(struct device *dev, unsigned long val) 315 { 316 struct i2c_client *client = to_i2c_client(dev); 317 struct g762_data *data = g762_update_client(dev); 318 int ret; 319 320 if (IS_ERR(data)) 321 return PTR_ERR(data); 322 323 mutex_lock(&data->update_lock); 324 switch (val) { 325 case 1: 326 data->fan_cmd1 &= ~G762_REG_FAN_CMD1_CLK_DIV_ID0; 327 data->fan_cmd1 &= ~G762_REG_FAN_CMD1_CLK_DIV_ID1; 328 break; 329 case 2: 330 data->fan_cmd1 |= G762_REG_FAN_CMD1_CLK_DIV_ID0; 331 data->fan_cmd1 &= ~G762_REG_FAN_CMD1_CLK_DIV_ID1; 332 break; 333 case 4: 334 data->fan_cmd1 &= ~G762_REG_FAN_CMD1_CLK_DIV_ID0; 335 data->fan_cmd1 |= G762_REG_FAN_CMD1_CLK_DIV_ID1; 336 break; 337 case 8: 338 data->fan_cmd1 |= G762_REG_FAN_CMD1_CLK_DIV_ID0; 339 data->fan_cmd1 |= G762_REG_FAN_CMD1_CLK_DIV_ID1; 340 break; 341 default: 342 ret = -EINVAL; 343 goto out; 344 } 345 ret = i2c_smbus_write_byte_data(client, G762_REG_FAN_CMD1, 346 data->fan_cmd1); 347 data->valid = false; 348 out: 349 mutex_unlock(&data->update_lock); 350 351 return ret; 352 } 353 354 /* Set fan gear mode. Accepts either 0, 1 or 2. */ 355 static int do_set_fan_gear_mode(struct device *dev, unsigned long val) 356 { 357 struct i2c_client *client = to_i2c_client(dev); 358 struct g762_data *data = g762_update_client(dev); 359 int ret; 360 361 if (IS_ERR(data)) 362 return PTR_ERR(data); 363 364 mutex_lock(&data->update_lock); 365 switch (val) { 366 case 0: 367 data->fan_cmd2 &= ~G762_REG_FAN_CMD2_GEAR_MODE_0; 368 data->fan_cmd2 &= ~G762_REG_FAN_CMD2_GEAR_MODE_1; 369 break; 370 case 1: 371 data->fan_cmd2 |= G762_REG_FAN_CMD2_GEAR_MODE_0; 372 data->fan_cmd2 &= ~G762_REG_FAN_CMD2_GEAR_MODE_1; 373 break; 374 case 2: 375 data->fan_cmd2 &= ~G762_REG_FAN_CMD2_GEAR_MODE_0; 376 data->fan_cmd2 |= G762_REG_FAN_CMD2_GEAR_MODE_1; 377 break; 378 default: 379 ret = -EINVAL; 380 goto out; 381 } 382 ret = i2c_smbus_write_byte_data(client, G762_REG_FAN_CMD2, 383 data->fan_cmd2); 384 data->valid = false; 385 out: 386 mutex_unlock(&data->update_lock); 387 388 return ret; 389 } 390 391 /* Set number of fan pulses per revolution. Accepts either 2 or 4. */ 392 static int do_set_fan_pulses(struct device *dev, unsigned long val) 393 { 394 struct i2c_client *client = to_i2c_client(dev); 395 struct g762_data *data = g762_update_client(dev); 396 int ret; 397 398 if (IS_ERR(data)) 399 return PTR_ERR(data); 400 401 mutex_lock(&data->update_lock); 402 switch (val) { 403 case 2: 404 data->fan_cmd1 &= ~G762_REG_FAN_CMD1_PULSE_PER_REV; 405 break; 406 case 4: 407 data->fan_cmd1 |= G762_REG_FAN_CMD1_PULSE_PER_REV; 408 break; 409 default: 410 ret = -EINVAL; 411 goto out; 412 } 413 ret = i2c_smbus_write_byte_data(client, G762_REG_FAN_CMD1, 414 data->fan_cmd1); 415 data->valid = false; 416 out: 417 mutex_unlock(&data->update_lock); 418 419 return ret; 420 } 421 422 /* Set fan mode. Accepts either 1 (open-loop) or 2 (closed-loop). */ 423 static int do_set_pwm_enable(struct device *dev, unsigned long val) 424 { 425 struct i2c_client *client = to_i2c_client(dev); 426 struct g762_data *data = g762_update_client(dev); 427 int ret; 428 429 if (IS_ERR(data)) 430 return PTR_ERR(data); 431 432 mutex_lock(&data->update_lock); 433 switch (val) { 434 case G762_FAN_MODE_CLOSED_LOOP: 435 data->fan_cmd1 |= G762_REG_FAN_CMD1_FAN_MODE; 436 break; 437 case G762_FAN_MODE_OPEN_LOOP: 438 data->fan_cmd1 &= ~G762_REG_FAN_CMD1_FAN_MODE; 439 /* 440 * BUG FIX: if SET_CNT register value is 255 then, for some 441 * unknown reason, fan will not rotate as expected, no matter 442 * the value of SET_OUT (to be specific, this seems to happen 443 * only in PWM mode). To workaround this bug, we give SET_CNT 444 * value of 254 if it is 255 when switching to open-loop. 445 */ 446 if (data->set_cnt == 0xff) 447 i2c_smbus_write_byte_data(client, G762_REG_SET_CNT, 448 254); 449 break; 450 default: 451 ret = -EINVAL; 452 goto out; 453 } 454 455 ret = i2c_smbus_write_byte_data(client, G762_REG_FAN_CMD1, 456 data->fan_cmd1); 457 data->valid = false; 458 out: 459 mutex_unlock(&data->update_lock); 460 461 return ret; 462 } 463 464 /* Set PWM polarity. Accepts either 0 (positive duty) or 1 (negative duty) */ 465 static int do_set_pwm_polarity(struct device *dev, unsigned long val) 466 { 467 struct i2c_client *client = to_i2c_client(dev); 468 struct g762_data *data = g762_update_client(dev); 469 int ret; 470 471 if (IS_ERR(data)) 472 return PTR_ERR(data); 473 474 mutex_lock(&data->update_lock); 475 switch (val) { 476 case G762_PWM_POLARITY_POSITIVE: 477 data->fan_cmd1 &= ~G762_REG_FAN_CMD1_PWM_POLARITY; 478 break; 479 case G762_PWM_POLARITY_NEGATIVE: 480 data->fan_cmd1 |= G762_REG_FAN_CMD1_PWM_POLARITY; 481 break; 482 default: 483 ret = -EINVAL; 484 goto out; 485 } 486 ret = i2c_smbus_write_byte_data(client, G762_REG_FAN_CMD1, 487 data->fan_cmd1); 488 data->valid = false; 489 out: 490 mutex_unlock(&data->update_lock); 491 492 return ret; 493 } 494 495 /* 496 * Set pwm value. Accepts values between 0 (stops the fan) and 497 * 255 (full speed). This only makes sense in open-loop mode. 498 */ 499 static int do_set_pwm(struct device *dev, unsigned long val) 500 { 501 struct i2c_client *client = to_i2c_client(dev); 502 struct g762_data *data = i2c_get_clientdata(client); 503 int ret; 504 505 if (val > 255) 506 return -EINVAL; 507 508 mutex_lock(&data->update_lock); 509 ret = i2c_smbus_write_byte_data(client, G762_REG_SET_OUT, val); 510 data->valid = false; 511 mutex_unlock(&data->update_lock); 512 513 return ret; 514 } 515 516 /* 517 * Set fan RPM value. Can be called both in closed and open-loop mode 518 * but effect will only be seen after closed-loop mode is configured. 519 */ 520 static int do_set_fan_target(struct device *dev, unsigned long val) 521 { 522 struct i2c_client *client = to_i2c_client(dev); 523 struct g762_data *data = g762_update_client(dev); 524 int ret; 525 526 if (IS_ERR(data)) 527 return PTR_ERR(data); 528 529 mutex_lock(&data->update_lock); 530 data->set_cnt = cnt_from_rpm(val, data->clk_freq, 531 G762_PULSE_FROM_REG(data->fan_cmd1), 532 G762_CLKDIV_FROM_REG(data->fan_cmd1), 533 G762_GEARMULT_FROM_REG(data->fan_cmd2)); 534 ret = i2c_smbus_write_byte_data(client, G762_REG_SET_CNT, 535 data->set_cnt); 536 data->valid = false; 537 mutex_unlock(&data->update_lock); 538 539 return ret; 540 } 541 542 /* Set fan startup voltage. Accepted values are either 0, 1, 2 or 3. */ 543 static int do_set_fan_startv(struct device *dev, unsigned long val) 544 { 545 struct i2c_client *client = to_i2c_client(dev); 546 struct g762_data *data = g762_update_client(dev); 547 int ret; 548 549 if (IS_ERR(data)) 550 return PTR_ERR(data); 551 552 mutex_lock(&data->update_lock); 553 switch (val) { 554 case 0: 555 data->fan_cmd2 &= ~G762_REG_FAN_CMD2_FAN_STARTV_0; 556 data->fan_cmd2 &= ~G762_REG_FAN_CMD2_FAN_STARTV_1; 557 break; 558 case 1: 559 data->fan_cmd2 |= G762_REG_FAN_CMD2_FAN_STARTV_0; 560 data->fan_cmd2 &= ~G762_REG_FAN_CMD2_FAN_STARTV_1; 561 break; 562 case 2: 563 data->fan_cmd2 &= ~G762_REG_FAN_CMD2_FAN_STARTV_0; 564 data->fan_cmd2 |= G762_REG_FAN_CMD2_FAN_STARTV_1; 565 break; 566 case 3: 567 data->fan_cmd2 |= G762_REG_FAN_CMD2_FAN_STARTV_0; 568 data->fan_cmd2 |= G762_REG_FAN_CMD2_FAN_STARTV_1; 569 break; 570 default: 571 ret = -EINVAL; 572 goto out; 573 } 574 ret = i2c_smbus_write_byte_data(client, G762_REG_FAN_CMD2, 575 data->fan_cmd2); 576 data->valid = false; 577 out: 578 mutex_unlock(&data->update_lock); 579 580 return ret; 581 } 582 583 /* 584 * Helper to import hardware characteristics from .dts file and push 585 * those to the chip. 586 */ 587 588 #ifdef CONFIG_OF 589 static const struct of_device_id g762_dt_match[] = { 590 { .compatible = "gmt,g762" }, 591 { .compatible = "gmt,g763" }, 592 { }, 593 }; 594 595 /* 596 * Grab clock (a required property), enable it, get (fixed) clock frequency 597 * and store it. Note: upon success, clock has been prepared and enabled; it 598 * must later be unprepared and disabled (e.g. during module unloading) by a 599 * call to g762_of_clock_disable(). Note that a reference to clock is kept 600 * in our private data structure to be used in this function. 601 */ 602 static int g762_of_clock_enable(struct i2c_client *client) 603 { 604 struct g762_data *data; 605 unsigned long clk_freq; 606 struct clk *clk; 607 int ret; 608 609 if (!client->dev.of_node) 610 return 0; 611 612 clk = of_clk_get(client->dev.of_node, 0); 613 if (IS_ERR(clk)) { 614 dev_err(&client->dev, "failed to get clock\n"); 615 return PTR_ERR(clk); 616 } 617 618 ret = clk_prepare_enable(clk); 619 if (ret) { 620 dev_err(&client->dev, "failed to enable clock\n"); 621 goto clk_put; 622 } 623 624 clk_freq = clk_get_rate(clk); 625 ret = do_set_clk_freq(&client->dev, clk_freq); 626 if (ret) { 627 dev_err(&client->dev, "invalid clock freq %lu\n", clk_freq); 628 goto clk_unprep; 629 } 630 631 data = i2c_get_clientdata(client); 632 data->clk = clk; 633 634 return 0; 635 636 clk_unprep: 637 clk_disable_unprepare(clk); 638 639 clk_put: 640 clk_put(clk); 641 642 return ret; 643 } 644 645 static void g762_of_clock_disable(struct i2c_client *client) 646 { 647 struct g762_data *data = i2c_get_clientdata(client); 648 649 if (!data->clk) 650 return; 651 652 clk_disable_unprepare(data->clk); 653 clk_put(data->clk); 654 } 655 656 static int g762_of_prop_import_one(struct i2c_client *client, 657 const char *pname, 658 int (*psetter)(struct device *dev, 659 unsigned long val)) 660 { 661 const __be32 *prop; 662 int len, ret; 663 u32 pval; 664 665 prop = of_get_property(client->dev.of_node, pname, &len); 666 if (!prop || len != sizeof(u32)) 667 return 0; 668 669 pval = be32_to_cpu(prop[0]); 670 dev_dbg(&client->dev, "found %s (%d)\n", pname, pval); 671 ret = (*psetter)(&client->dev, pval); 672 if (ret) 673 dev_err(&client->dev, "unable to set %s (%d)\n", pname, pval); 674 675 return ret; 676 } 677 678 static int g762_of_prop_import(struct i2c_client *client) 679 { 680 int ret; 681 682 if (!client->dev.of_node) 683 return 0; 684 685 ret = g762_of_prop_import_one(client, "fan_gear_mode", 686 do_set_fan_gear_mode); 687 if (ret) 688 return ret; 689 690 ret = g762_of_prop_import_one(client, "pwm_polarity", 691 do_set_pwm_polarity); 692 if (ret) 693 return ret; 694 695 return g762_of_prop_import_one(client, "fan_startv", 696 do_set_fan_startv); 697 } 698 699 #else 700 static int g762_of_prop_import(struct i2c_client *client) 701 { 702 return 0; 703 } 704 705 static int g762_of_clock_enable(struct i2c_client *client) 706 { 707 return 0; 708 } 709 710 static void g762_of_clock_disable(struct i2c_client *client) { } 711 #endif 712 713 /* 714 * Helper to import hardware characteristics from .dts file and push 715 * those to the chip. 716 */ 717 718 static int g762_pdata_prop_import(struct i2c_client *client) 719 { 720 struct g762_platform_data *pdata = dev_get_platdata(&client->dev); 721 int ret; 722 723 if (!pdata) 724 return 0; 725 726 ret = do_set_fan_gear_mode(&client->dev, pdata->fan_gear_mode); 727 if (ret) 728 return ret; 729 730 ret = do_set_pwm_polarity(&client->dev, pdata->pwm_polarity); 731 if (ret) 732 return ret; 733 734 ret = do_set_fan_startv(&client->dev, pdata->fan_startv); 735 if (ret) 736 return ret; 737 738 return do_set_clk_freq(&client->dev, pdata->clk_freq); 739 } 740 741 /* 742 * sysfs attributes 743 */ 744 745 /* 746 * Read function for fan1_input sysfs file. Return current fan RPM value, or 747 * 0 if fan is out of control. 748 */ 749 static ssize_t get_fan_rpm(struct device *dev, struct device_attribute *da, 750 char *buf) 751 { 752 struct g762_data *data = g762_update_client(dev); 753 unsigned int rpm = 0; 754 755 if (IS_ERR(data)) 756 return PTR_ERR(data); 757 758 mutex_lock(&data->update_lock); 759 /* reverse logic: fan out of control reporting is enabled low */ 760 if (data->fan_sta & G762_REG_FAN_STA_OOC) { 761 rpm = rpm_from_cnt(data->act_cnt, data->clk_freq, 762 G762_PULSE_FROM_REG(data->fan_cmd1), 763 G762_CLKDIV_FROM_REG(data->fan_cmd1), 764 G762_GEARMULT_FROM_REG(data->fan_cmd2)); 765 } 766 mutex_unlock(&data->update_lock); 767 768 return sprintf(buf, "%u\n", rpm); 769 } 770 771 /* 772 * Read and write functions for pwm1_mode sysfs file. Get and set fan speed 773 * control mode i.e. PWM (1) or DC (0). 774 */ 775 static ssize_t get_pwm_mode(struct device *dev, struct device_attribute *da, 776 char *buf) 777 { 778 struct g762_data *data = g762_update_client(dev); 779 780 if (IS_ERR(data)) 781 return PTR_ERR(data); 782 783 return sprintf(buf, "%d\n", 784 !!(data->fan_cmd1 & G762_REG_FAN_CMD1_OUT_MODE)); 785 } 786 787 static ssize_t set_pwm_mode(struct device *dev, struct device_attribute *da, 788 const char *buf, size_t count) 789 { 790 unsigned long val; 791 int ret; 792 793 if (kstrtoul(buf, 10, &val)) 794 return -EINVAL; 795 796 ret = do_set_pwm_mode(dev, val); 797 if (ret < 0) 798 return ret; 799 800 return count; 801 } 802 803 /* 804 * Read and write functions for fan1_div sysfs file. Get and set fan 805 * controller prescaler value 806 */ 807 static ssize_t get_fan_div(struct device *dev, 808 struct device_attribute *da, char *buf) 809 { 810 struct g762_data *data = g762_update_client(dev); 811 812 if (IS_ERR(data)) 813 return PTR_ERR(data); 814 815 return sprintf(buf, "%d\n", G762_CLKDIV_FROM_REG(data->fan_cmd1)); 816 } 817 818 static ssize_t set_fan_div(struct device *dev, 819 struct device_attribute *da, 820 const char *buf, size_t count) 821 { 822 unsigned long val; 823 int ret; 824 825 if (kstrtoul(buf, 10, &val)) 826 return -EINVAL; 827 828 ret = do_set_fan_div(dev, val); 829 if (ret < 0) 830 return ret; 831 832 return count; 833 } 834 835 /* 836 * Read and write functions for fan1_pulses sysfs file. Get and set number 837 * of tachometer pulses per fan revolution. 838 */ 839 static ssize_t get_fan_pulses(struct device *dev, 840 struct device_attribute *da, char *buf) 841 { 842 struct g762_data *data = g762_update_client(dev); 843 844 if (IS_ERR(data)) 845 return PTR_ERR(data); 846 847 return sprintf(buf, "%d\n", G762_PULSE_FROM_REG(data->fan_cmd1)); 848 } 849 850 static ssize_t set_fan_pulses(struct device *dev, 851 struct device_attribute *da, 852 const char *buf, size_t count) 853 { 854 unsigned long val; 855 int ret; 856 857 if (kstrtoul(buf, 10, &val)) 858 return -EINVAL; 859 860 ret = do_set_fan_pulses(dev, val); 861 if (ret < 0) 862 return ret; 863 864 return count; 865 } 866 867 /* 868 * Read and write functions for pwm1_enable. Get and set fan speed control mode 869 * (i.e. closed or open-loop). 870 * 871 * Following documentation about hwmon's sysfs interface, a pwm1_enable node 872 * should accept followings: 873 * 874 * 0 : no fan speed control (i.e. fan at full speed) 875 * 1 : manual fan speed control enabled (use pwm[1-*]) (open-loop) 876 * 2+: automatic fan speed control enabled (use fan[1-*]_target) (closed-loop) 877 * 878 * but we do not accept 0 as this mode is not natively supported by the chip 879 * and it is not emulated by g762 driver. -EINVAL is returned in this case. 880 */ 881 static ssize_t get_pwm_enable(struct device *dev, 882 struct device_attribute *da, char *buf) 883 { 884 struct g762_data *data = g762_update_client(dev); 885 886 if (IS_ERR(data)) 887 return PTR_ERR(data); 888 889 return sprintf(buf, "%d\n", 890 (!!(data->fan_cmd1 & G762_REG_FAN_CMD1_FAN_MODE)) + 1); 891 } 892 893 static ssize_t set_pwm_enable(struct device *dev, 894 struct device_attribute *da, 895 const char *buf, size_t count) 896 { 897 unsigned long val; 898 int ret; 899 900 if (kstrtoul(buf, 10, &val)) 901 return -EINVAL; 902 903 ret = do_set_pwm_enable(dev, val); 904 if (ret < 0) 905 return ret; 906 907 return count; 908 } 909 910 /* 911 * Read and write functions for pwm1 sysfs file. Get and set pwm value 912 * (which affects fan speed) in open-loop mode. 0 stops the fan and 255 913 * makes it run at full speed. 914 */ 915 static ssize_t get_pwm(struct device *dev, struct device_attribute *da, 916 char *buf) 917 { 918 struct g762_data *data = g762_update_client(dev); 919 920 if (IS_ERR(data)) 921 return PTR_ERR(data); 922 923 return sprintf(buf, "%d\n", data->set_out); 924 } 925 926 static ssize_t set_pwm(struct device *dev, struct device_attribute *da, 927 const char *buf, size_t count) 928 { 929 unsigned long val; 930 int ret; 931 932 if (kstrtoul(buf, 10, &val)) 933 return -EINVAL; 934 935 ret = do_set_pwm(dev, val); 936 if (ret < 0) 937 return ret; 938 939 return count; 940 } 941 942 /* 943 * Read and write function for fan1_target sysfs file. Get/set the fan speed in 944 * closed-loop mode. Speed is given as a RPM value; then the chip will regulate 945 * the fan speed using pulses from fan tachometer. 946 * 947 * Refer to rpm_from_cnt() implementation above to get info about count number 948 * calculation. 949 * 950 * Also note that due to rounding errors it is possible that you don't read 951 * back exactly the value you have set. 952 */ 953 static ssize_t get_fan_target(struct device *dev, struct device_attribute *da, 954 char *buf) 955 { 956 struct g762_data *data = g762_update_client(dev); 957 unsigned int rpm; 958 959 if (IS_ERR(data)) 960 return PTR_ERR(data); 961 962 mutex_lock(&data->update_lock); 963 rpm = rpm_from_cnt(data->set_cnt, data->clk_freq, 964 G762_PULSE_FROM_REG(data->fan_cmd1), 965 G762_CLKDIV_FROM_REG(data->fan_cmd1), 966 G762_GEARMULT_FROM_REG(data->fan_cmd2)); 967 mutex_unlock(&data->update_lock); 968 969 return sprintf(buf, "%u\n", rpm); 970 } 971 972 static ssize_t set_fan_target(struct device *dev, struct device_attribute *da, 973 const char *buf, size_t count) 974 { 975 unsigned long val; 976 int ret; 977 978 if (kstrtoul(buf, 10, &val)) 979 return -EINVAL; 980 981 ret = do_set_fan_target(dev, val); 982 if (ret < 0) 983 return ret; 984 985 return count; 986 } 987 988 /* read function for fan1_fault sysfs file. */ 989 static ssize_t get_fan_failure(struct device *dev, struct device_attribute *da, 990 char *buf) 991 { 992 struct g762_data *data = g762_update_client(dev); 993 994 if (IS_ERR(data)) 995 return PTR_ERR(data); 996 997 return sprintf(buf, "%u\n", !!(data->fan_sta & G762_REG_FAN_STA_FAIL)); 998 } 999 1000 /* 1001 * read function for fan1_alarm sysfs file. Note that OOC condition is 1002 * enabled low 1003 */ 1004 static ssize_t get_fan_ooc(struct device *dev, struct device_attribute *da, 1005 char *buf) 1006 { 1007 struct g762_data *data = g762_update_client(dev); 1008 1009 if (IS_ERR(data)) 1010 return PTR_ERR(data); 1011 1012 return sprintf(buf, "%u\n", !(data->fan_sta & G762_REG_FAN_STA_OOC)); 1013 } 1014 1015 static DEVICE_ATTR(pwm1, S_IWUSR | S_IRUGO, get_pwm, set_pwm); 1016 static DEVICE_ATTR(pwm1_mode, S_IWUSR | S_IRUGO, get_pwm_mode, set_pwm_mode); 1017 static DEVICE_ATTR(pwm1_enable, S_IWUSR | S_IRUGO, 1018 get_pwm_enable, set_pwm_enable); 1019 static DEVICE_ATTR(fan1_input, S_IRUGO, get_fan_rpm, NULL); 1020 static DEVICE_ATTR(fan1_alarm, S_IRUGO, get_fan_ooc, NULL); 1021 static DEVICE_ATTR(fan1_fault, S_IRUGO, get_fan_failure, NULL); 1022 static DEVICE_ATTR(fan1_target, S_IWUSR | S_IRUGO, 1023 get_fan_target, set_fan_target); 1024 static DEVICE_ATTR(fan1_div, S_IWUSR | S_IRUGO, get_fan_div, set_fan_div); 1025 static DEVICE_ATTR(fan1_pulses, S_IWUSR | S_IRUGO, 1026 get_fan_pulses, set_fan_pulses); 1027 1028 /* Driver data */ 1029 static struct attribute *g762_attributes[] = { 1030 &dev_attr_fan1_input.attr, 1031 &dev_attr_fan1_alarm.attr, 1032 &dev_attr_fan1_fault.attr, 1033 &dev_attr_fan1_target.attr, 1034 &dev_attr_fan1_div.attr, 1035 &dev_attr_fan1_pulses.attr, 1036 &dev_attr_pwm1.attr, 1037 &dev_attr_pwm1_mode.attr, 1038 &dev_attr_pwm1_enable.attr, 1039 NULL 1040 }; 1041 1042 static const struct attribute_group g762_group = { 1043 .attrs = g762_attributes, 1044 }; 1045 1046 /* 1047 * Enable both fan failure detection and fan out of control protection. The 1048 * function does not protect change/access to data structure; it must thus 1049 * only be called during initialization. 1050 */ 1051 static inline int g762_fan_init(struct device *dev) 1052 { 1053 struct i2c_client *client = to_i2c_client(dev); 1054 struct g762_data *data = g762_update_client(dev); 1055 1056 if (IS_ERR(data)) 1057 return PTR_ERR(data); 1058 1059 data->fan_cmd1 |= G762_REG_FAN_CMD1_DET_FAN_FAIL; 1060 data->fan_cmd1 |= G762_REG_FAN_CMD1_DET_FAN_OOC; 1061 data->valid = false; 1062 1063 return i2c_smbus_write_byte_data(client, G762_REG_FAN_CMD1, 1064 data->fan_cmd1); 1065 } 1066 1067 static int g762_probe(struct i2c_client *client, const struct i2c_device_id *id) 1068 { 1069 struct g762_data *data; 1070 int ret; 1071 1072 if (!i2c_check_functionality(client->adapter, 1073 I2C_FUNC_SMBUS_BYTE_DATA)) 1074 return -ENODEV; 1075 1076 data = devm_kzalloc(&client->dev, sizeof(struct g762_data), GFP_KERNEL); 1077 if (!data) 1078 return -ENOMEM; 1079 1080 i2c_set_clientdata(client, data); 1081 data->client = client; 1082 mutex_init(&data->update_lock); 1083 1084 /* Enable fan failure detection and fan out of control protection */ 1085 ret = g762_fan_init(&client->dev); 1086 if (ret) 1087 return ret; 1088 1089 /* Get configuration via DT ... */ 1090 ret = g762_of_clock_enable(client); 1091 if (ret) 1092 return ret; 1093 ret = g762_of_prop_import(client); 1094 if (ret) 1095 goto clock_dis; 1096 /* ... or platform_data */ 1097 ret = g762_pdata_prop_import(client); 1098 if (ret) 1099 goto clock_dis; 1100 1101 /* Register sysfs hooks */ 1102 ret = sysfs_create_group(&client->dev.kobj, &g762_group); 1103 if (ret) 1104 goto clock_dis; 1105 1106 data->hwmon_dev = hwmon_device_register(&client->dev); 1107 if (IS_ERR(data->hwmon_dev)) { 1108 ret = PTR_ERR(data->hwmon_dev); 1109 goto sysfs_rem; 1110 } 1111 1112 return 0; 1113 1114 sysfs_rem: 1115 sysfs_remove_group(&client->dev.kobj, &g762_group); 1116 1117 clock_dis: 1118 g762_of_clock_disable(client); 1119 1120 return ret; 1121 } 1122 1123 static int g762_remove(struct i2c_client *client) 1124 { 1125 struct g762_data *data = i2c_get_clientdata(client); 1126 1127 hwmon_device_unregister(data->hwmon_dev); 1128 sysfs_remove_group(&client->dev.kobj, &g762_group); 1129 g762_of_clock_disable(client); 1130 1131 return 0; 1132 } 1133 1134 static struct i2c_driver g762_driver = { 1135 .driver = { 1136 .name = DRVNAME, 1137 .owner = THIS_MODULE, 1138 .of_match_table = of_match_ptr(g762_dt_match), 1139 }, 1140 .probe = g762_probe, 1141 .remove = g762_remove, 1142 .id_table = g762_id, 1143 }; 1144 1145 module_i2c_driver(g762_driver); 1146 1147 MODULE_AUTHOR("Arnaud EBALARD <arno@natisbad.org>"); 1148 MODULE_DESCRIPTION("GMT G762/G763 driver"); 1149 MODULE_LICENSE("GPL"); 1150