Linux Audio

Check our new training course

Loading...
Note: File does not exist in v3.1.
   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * g762 - Driver for the Global Mixed-mode Technology Inc. fan speed
   4 *        PWM controller chips from G762 family, i.e. G762 and G763
   5 *
   6 * Copyright (C) 2013, Arnaud EBALARD <arno@natisbad.org>
   7 *
   8 * This work is based on a basic version for 2.6.31 kernel developed
   9 * by Olivier Mouchet for LaCie. Updates and correction have been
  10 * performed to run on recent kernels. Additional features, like the
  11 * ability to configure various characteristics via .dts file or
  12 * board init file have been added. Detailed datasheet on which this
  13 * development is based is available here:
  14 *
  15 *  http://natisbad.org/NAS/refs/GMT_EDS-762_763-080710-0.2.pdf
  16 *
  17 * Headers from previous developments have been kept below:
  18 *
  19 * Copyright (c) 2009 LaCie
  20 *
  21 * Author: Olivier Mouchet <olivier.mouchet@gmail.com>
  22 *
  23 * based on g760a code written by Herbert Valerio Riedel <hvr@gnu.org>
  24 * Copyright (C) 2007  Herbert Valerio Riedel <hvr@gnu.org>
  25 *
  26 * g762: minimal datasheet available at:
  27 *       http://www.gmt.com.tw/product/datasheet/EDS-762_3.pdf
  28 */
  29
  30#include <linux/device.h>
  31#include <linux/module.h>
  32#include <linux/init.h>
  33#include <linux/jiffies.h>
  34#include <linux/i2c.h>
  35#include <linux/hwmon.h>
  36#include <linux/hwmon-sysfs.h>
  37#include <linux/err.h>
  38#include <linux/mutex.h>
  39#include <linux/kernel.h>
  40#include <linux/clk.h>
  41#include <linux/of.h>
  42#include <linux/platform_data/g762.h>
  43
  44#define DRVNAME "g762"
  45
  46static const struct i2c_device_id g762_id[] = {
  47	{ "g761" },
  48	{ "g762" },
  49	{ "g763" },
  50	{ }
  51};
  52MODULE_DEVICE_TABLE(i2c, g762_id);
  53
  54enum g762_regs {
  55	G762_REG_SET_CNT  = 0x00,
  56	G762_REG_ACT_CNT  = 0x01,
  57	G762_REG_FAN_STA  = 0x02,
  58	G762_REG_SET_OUT  = 0x03,
  59	G762_REG_FAN_CMD1 = 0x04,
  60	G762_REG_FAN_CMD2 = 0x05,
  61};
  62
  63/* Config register bits */
  64#define G762_REG_FAN_CMD1_DET_FAN_FAIL  0x80 /* enable fan_fail signal */
  65#define G762_REG_FAN_CMD1_DET_FAN_OOC   0x40 /* enable fan_out_of_control */
  66#define G762_REG_FAN_CMD1_OUT_MODE      0x20 /* out mode: PWM or DC */
  67#define G762_REG_FAN_CMD1_FAN_MODE      0x10 /* fan mode: closed/open-loop */
  68#define G762_REG_FAN_CMD1_CLK_DIV_ID1   0x08 /* clock divisor value */
  69#define G762_REG_FAN_CMD1_CLK_DIV_ID0   0x04
  70#define G762_REG_FAN_CMD1_PWM_POLARITY  0x02 /* PWM polarity */
  71#define G762_REG_FAN_CMD1_PULSE_PER_REV 0x01 /* pulse per fan revolution */
  72
  73#define G761_REG_FAN_CMD2_FAN_CLOCK     0x20 /* choose internal clock*/
  74#define G762_REG_FAN_CMD2_GEAR_MODE_1   0x08 /* fan gear mode */
  75#define G762_REG_FAN_CMD2_GEAR_MODE_0   0x04
  76#define G762_REG_FAN_CMD2_FAN_STARTV_1  0x02 /* fan startup voltage */
  77#define G762_REG_FAN_CMD2_FAN_STARTV_0  0x01
  78
  79#define G762_REG_FAN_STA_FAIL           0x02 /* fan fail */
  80#define G762_REG_FAN_STA_OOC            0x01 /* fan out of control */
  81
  82/* Config register values */
  83#define G762_OUT_MODE_PWM            1
  84#define G762_OUT_MODE_DC             0
  85
  86#define G762_FAN_MODE_CLOSED_LOOP    2
  87#define G762_FAN_MODE_OPEN_LOOP      1
  88
  89#define G762_PWM_POLARITY_NEGATIVE   1
  90#define G762_PWM_POLARITY_POSITIVE   0
  91
  92/* Register data is read (and cached) at most once per second. */
  93#define G762_UPDATE_INTERVAL    HZ
  94
  95/*
  96 * Extract pulse count per fan revolution value (2 or 4) from given
  97 * FAN_CMD1 register value.
  98 */
  99#define G762_PULSE_FROM_REG(reg) \
 100	((((reg) & G762_REG_FAN_CMD1_PULSE_PER_REV) + 1) << 1)
 101
 102/*
 103 * Extract fan clock divisor (1, 2, 4 or 8) from given FAN_CMD1
 104 * register value.
 105 */
 106#define G762_CLKDIV_FROM_REG(reg) \
 107	(1 << (((reg) & (G762_REG_FAN_CMD1_CLK_DIV_ID0 |	\
 108			 G762_REG_FAN_CMD1_CLK_DIV_ID1)) >> 2))
 109
 110/*
 111 * Extract fan gear mode multiplier value (0, 2 or 4) from given
 112 * FAN_CMD2 register value.
 113 */
 114#define G762_GEARMULT_FROM_REG(reg) \
 115	(1 << (((reg) & (G762_REG_FAN_CMD2_GEAR_MODE_0 |	\
 116			 G762_REG_FAN_CMD2_GEAR_MODE_1)) >> 2))
 117
 118struct g762_data {
 119	struct i2c_client *client;
 120	bool internal_clock;
 121	struct clk *clk;
 122
 123	/* update mutex */
 124	struct mutex update_lock;
 125
 126	/* board specific parameters. */
 127	u32 clk_freq;
 128
 129	/* g762 register cache */
 130	bool valid;
 131	unsigned long last_updated; /* in jiffies */
 132
 133	u8 set_cnt;  /* controls fan rotation speed in closed-loop mode */
 134	u8 act_cnt;  /* provides access to current fan RPM value */
 135	u8 fan_sta;  /* bit 0: set when actual fan speed is more than
 136		      *        25% outside requested fan speed
 137		      * bit 1: set when no transition occurs on fan
 138		      *        pin for 0.7s
 139		      */
 140	u8 set_out;  /* controls fan rotation speed in open-loop mode */
 141	u8 fan_cmd1; /*   0: FG_PLS_ID0 FG pulses count per revolution
 142		      *      0: 2 counts per revolution
 143		      *      1: 4 counts per revolution
 144		      *   1: PWM_POLARITY 1: negative_duty
 145		      *                   0: positive_duty
 146		      * 2,3: [FG_CLOCK_ID0, FG_CLK_ID1]
 147		      *         00: Divide fan clock by 1
 148		      *         01: Divide fan clock by 2
 149		      *         10: Divide fan clock by 4
 150		      *         11: Divide fan clock by 8
 151		      *   4: FAN_MODE 1:closed-loop, 0:open-loop
 152		      *   5: OUT_MODE 1:PWM, 0:DC
 153		      *   6: DET_FAN_OOC enable "fan ooc" status
 154		      *   7: DET_FAN_FAIL enable "fan fail" status
 155		      */
 156	u8 fan_cmd2; /* 0,1: FAN_STARTV 0,1,2,3 -> 0,32,64,96 dac_code
 157		      * 2,3: FG_GEAR_MODE
 158		      *         00: multiplier = 1
 159		      *         01: multiplier = 2
 160		      *         10: multiplier = 4
 161		      *   4: Mask ALERT# (g763 only)
 162		      */
 163};
 164
 165/*
 166 * Convert count value from fan controller register (FAN_SET_CNT) into fan
 167 * speed RPM value. Note that the datasheet documents a basic formula;
 168 * influence of additional parameters (fan clock divisor, fan gear mode)
 169 * have been infered from examples in the datasheet and tests.
 170 */
 171static inline unsigned int rpm_from_cnt(u8 cnt, u32 clk_freq, u16 p,
 172					u8 clk_div, u8 gear_mult)
 173{
 174	if (cnt == 0xff)  /* setting cnt to 255 stops the fan */
 175		return 0;
 176
 177	return (clk_freq * 30 * gear_mult) / ((cnt ? cnt : 1) * p * clk_div);
 178}
 179
 180/*
 181 * Convert fan RPM value from sysfs into count value for fan controller
 182 * register (FAN_SET_CNT).
 183 */
 184static inline unsigned char cnt_from_rpm(unsigned long rpm, u32 clk_freq, u16 p,
 185					 u8 clk_div, u8 gear_mult)
 186{
 187	unsigned long f1 = clk_freq * 30 * gear_mult;
 188	unsigned long f2 = p * clk_div;
 189
 190	if (!rpm)	/* to stop the fan, set cnt to 255 */
 191		return 0xff;
 192
 193	rpm = clamp_val(rpm, f1 / (255 * f2), ULONG_MAX / f2);
 194	return DIV_ROUND_CLOSEST(f1, rpm * f2);
 195}
 196
 197/* helper to grab and cache data, at most one time per second */
 198static struct g762_data *g762_update_client(struct device *dev)
 199{
 200	struct g762_data *data = dev_get_drvdata(dev);
 201	struct i2c_client *client = data->client;
 202	int ret = 0;
 203
 204	mutex_lock(&data->update_lock);
 205	if (time_before(jiffies, data->last_updated + G762_UPDATE_INTERVAL) &&
 206	    likely(data->valid))
 207		goto out;
 208
 209	ret = i2c_smbus_read_byte_data(client, G762_REG_SET_CNT);
 210	if (ret < 0)
 211		goto out;
 212	data->set_cnt = ret;
 213
 214	ret = i2c_smbus_read_byte_data(client, G762_REG_ACT_CNT);
 215	if (ret < 0)
 216		goto out;
 217	data->act_cnt = ret;
 218
 219	ret = i2c_smbus_read_byte_data(client, G762_REG_FAN_STA);
 220	if (ret < 0)
 221		goto out;
 222	data->fan_sta = ret;
 223
 224	ret = i2c_smbus_read_byte_data(client, G762_REG_SET_OUT);
 225	if (ret < 0)
 226		goto out;
 227	data->set_out = ret;
 228
 229	ret = i2c_smbus_read_byte_data(client, G762_REG_FAN_CMD1);
 230	if (ret < 0)
 231		goto out;
 232	data->fan_cmd1 = ret;
 233
 234	ret = i2c_smbus_read_byte_data(client, G762_REG_FAN_CMD2);
 235	if (ret < 0)
 236		goto out;
 237	data->fan_cmd2 = ret;
 238
 239	data->last_updated = jiffies;
 240	data->valid = true;
 241 out:
 242	mutex_unlock(&data->update_lock);
 243
 244	if (ret < 0) /* upon error, encode it in return value */
 245		data = ERR_PTR(ret);
 246
 247	return data;
 248}
 249
 250/* helpers for writing hardware parameters */
 251
 252/*
 253 * Set input clock frequency received on CLK pin of the chip. Accepted values
 254 * are between 0 and 0xffffff. If zero is given, then default frequency
 255 * (32,768Hz) is used. Note that clock frequency is a characteristic of the
 256 * system but an internal parameter, i.e. value is not passed to the device.
 257 */
 258static int do_set_clk_freq(struct device *dev, unsigned long val)
 259{
 260	struct g762_data *data = dev_get_drvdata(dev);
 261
 262	if (val > 0xffffff)
 263		return -EINVAL;
 264	if (!val)
 265		val = 32768;
 266
 267	data->clk_freq = val;
 268
 269	return 0;
 270}
 271
 272/* Set pwm mode. Accepts either 0 (PWM mode) or 1 (DC mode) */
 273static int do_set_pwm_mode(struct device *dev, unsigned long val)
 274{
 275	struct g762_data *data = g762_update_client(dev);
 276	int ret;
 277
 278	if (IS_ERR(data))
 279		return PTR_ERR(data);
 280
 281	mutex_lock(&data->update_lock);
 282	switch (val) {
 283	case G762_OUT_MODE_PWM:
 284		data->fan_cmd1 |=  G762_REG_FAN_CMD1_OUT_MODE;
 285		break;
 286	case G762_OUT_MODE_DC:
 287		data->fan_cmd1 &= ~G762_REG_FAN_CMD1_OUT_MODE;
 288		break;
 289	default:
 290		ret = -EINVAL;
 291		goto out;
 292	}
 293	ret = i2c_smbus_write_byte_data(data->client, G762_REG_FAN_CMD1,
 294					data->fan_cmd1);
 295	data->valid = false;
 296 out:
 297	mutex_unlock(&data->update_lock);
 298
 299	return ret;
 300}
 301
 302/* Set fan clock divisor. Accepts either 1, 2, 4 or 8. */
 303static int do_set_fan_div(struct device *dev, unsigned long val)
 304{
 305	struct g762_data *data = g762_update_client(dev);
 306	int ret;
 307
 308	if (IS_ERR(data))
 309		return PTR_ERR(data);
 310
 311	mutex_lock(&data->update_lock);
 312	switch (val) {
 313	case 1:
 314		data->fan_cmd1 &= ~G762_REG_FAN_CMD1_CLK_DIV_ID0;
 315		data->fan_cmd1 &= ~G762_REG_FAN_CMD1_CLK_DIV_ID1;
 316		break;
 317	case 2:
 318		data->fan_cmd1 |=  G762_REG_FAN_CMD1_CLK_DIV_ID0;
 319		data->fan_cmd1 &= ~G762_REG_FAN_CMD1_CLK_DIV_ID1;
 320		break;
 321	case 4:
 322		data->fan_cmd1 &= ~G762_REG_FAN_CMD1_CLK_DIV_ID0;
 323		data->fan_cmd1 |=  G762_REG_FAN_CMD1_CLK_DIV_ID1;
 324		break;
 325	case 8:
 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	default:
 330		ret = -EINVAL;
 331		goto out;
 332	}
 333	ret = i2c_smbus_write_byte_data(data->client, G762_REG_FAN_CMD1,
 334					data->fan_cmd1);
 335	data->valid = false;
 336 out:
 337	mutex_unlock(&data->update_lock);
 338
 339	return ret;
 340}
 341
 342/* Set fan gear mode. Accepts either 0, 1 or 2. */
 343static int do_set_fan_gear_mode(struct device *dev, unsigned long val)
 344{
 345	struct g762_data *data = g762_update_client(dev);
 346	int ret;
 347
 348	if (IS_ERR(data))
 349		return PTR_ERR(data);
 350
 351	mutex_lock(&data->update_lock);
 352	switch (val) {
 353	case 0:
 354		data->fan_cmd2 &= ~G762_REG_FAN_CMD2_GEAR_MODE_0;
 355		data->fan_cmd2 &= ~G762_REG_FAN_CMD2_GEAR_MODE_1;
 356		break;
 357	case 1:
 358		data->fan_cmd2 |=  G762_REG_FAN_CMD2_GEAR_MODE_0;
 359		data->fan_cmd2 &= ~G762_REG_FAN_CMD2_GEAR_MODE_1;
 360		break;
 361	case 2:
 362		data->fan_cmd2 &= ~G762_REG_FAN_CMD2_GEAR_MODE_0;
 363		data->fan_cmd2 |=  G762_REG_FAN_CMD2_GEAR_MODE_1;
 364		break;
 365	default:
 366		ret = -EINVAL;
 367		goto out;
 368	}
 369	ret = i2c_smbus_write_byte_data(data->client, G762_REG_FAN_CMD2,
 370					data->fan_cmd2);
 371	data->valid = false;
 372 out:
 373	mutex_unlock(&data->update_lock);
 374
 375	return ret;
 376}
 377
 378/* Set number of fan pulses per revolution. Accepts either 2 or 4. */
 379static int do_set_fan_pulses(struct device *dev, unsigned long val)
 380{
 381	struct g762_data *data = g762_update_client(dev);
 382	int ret;
 383
 384	if (IS_ERR(data))
 385		return PTR_ERR(data);
 386
 387	mutex_lock(&data->update_lock);
 388	switch (val) {
 389	case 2:
 390		data->fan_cmd1 &= ~G762_REG_FAN_CMD1_PULSE_PER_REV;
 391		break;
 392	case 4:
 393		data->fan_cmd1 |=  G762_REG_FAN_CMD1_PULSE_PER_REV;
 394		break;
 395	default:
 396		ret = -EINVAL;
 397		goto out;
 398	}
 399	ret = i2c_smbus_write_byte_data(data->client, G762_REG_FAN_CMD1,
 400					data->fan_cmd1);
 401	data->valid = false;
 402 out:
 403	mutex_unlock(&data->update_lock);
 404
 405	return ret;
 406}
 407
 408/* Set fan mode. Accepts either 1 (open-loop) or 2 (closed-loop). */
 409static int do_set_pwm_enable(struct device *dev, unsigned long val)
 410{
 411	struct g762_data *data = g762_update_client(dev);
 412	int ret;
 413
 414	if (IS_ERR(data))
 415		return PTR_ERR(data);
 416
 417	mutex_lock(&data->update_lock);
 418	switch (val) {
 419	case G762_FAN_MODE_CLOSED_LOOP:
 420		data->fan_cmd1 |=  G762_REG_FAN_CMD1_FAN_MODE;
 421		break;
 422	case G762_FAN_MODE_OPEN_LOOP:
 423		data->fan_cmd1 &= ~G762_REG_FAN_CMD1_FAN_MODE;
 424		/*
 425		 * BUG FIX: if SET_CNT register value is 255 then, for some
 426		 * unknown reason, fan will not rotate as expected, no matter
 427		 * the value of SET_OUT (to be specific, this seems to happen
 428		 * only in PWM mode). To workaround this bug, we give SET_CNT
 429		 * value of 254 if it is 255 when switching to open-loop.
 430		 */
 431		if (data->set_cnt == 0xff)
 432			i2c_smbus_write_byte_data(data->client,
 433						  G762_REG_SET_CNT, 254);
 434		break;
 435	default:
 436		ret = -EINVAL;
 437		goto out;
 438	}
 439
 440	ret = i2c_smbus_write_byte_data(data->client, G762_REG_FAN_CMD1,
 441					data->fan_cmd1);
 442	data->valid = false;
 443 out:
 444	mutex_unlock(&data->update_lock);
 445
 446	return ret;
 447}
 448
 449/* Set PWM polarity. Accepts either 0 (positive duty) or 1 (negative duty) */
 450static int do_set_pwm_polarity(struct device *dev, unsigned long val)
 451{
 452	struct g762_data *data = g762_update_client(dev);
 453	int ret;
 454
 455	if (IS_ERR(data))
 456		return PTR_ERR(data);
 457
 458	mutex_lock(&data->update_lock);
 459	switch (val) {
 460	case G762_PWM_POLARITY_POSITIVE:
 461		data->fan_cmd1 &= ~G762_REG_FAN_CMD1_PWM_POLARITY;
 462		break;
 463	case G762_PWM_POLARITY_NEGATIVE:
 464		data->fan_cmd1 |=  G762_REG_FAN_CMD1_PWM_POLARITY;
 465		break;
 466	default:
 467		ret = -EINVAL;
 468		goto out;
 469	}
 470	ret = i2c_smbus_write_byte_data(data->client, G762_REG_FAN_CMD1,
 471					data->fan_cmd1);
 472	data->valid = false;
 473 out:
 474	mutex_unlock(&data->update_lock);
 475
 476	return ret;
 477}
 478
 479/*
 480 * Set pwm value. Accepts values between 0 (stops the fan) and
 481 * 255 (full speed). This only makes sense in open-loop mode.
 482 */
 483static int do_set_pwm(struct device *dev, unsigned long val)
 484{
 485	struct g762_data *data = dev_get_drvdata(dev);
 486	struct i2c_client *client = data->client;
 487	int ret;
 488
 489	if (val > 255)
 490		return -EINVAL;
 491
 492	mutex_lock(&data->update_lock);
 493	ret = i2c_smbus_write_byte_data(client, G762_REG_SET_OUT, val);
 494	data->valid = false;
 495	mutex_unlock(&data->update_lock);
 496
 497	return ret;
 498}
 499
 500/*
 501 * Set fan RPM value. Can be called both in closed and open-loop mode
 502 * but effect will only be seen after closed-loop mode is configured.
 503 */
 504static int do_set_fan_target(struct device *dev, unsigned long val)
 505{
 506	struct g762_data *data = g762_update_client(dev);
 507	int ret;
 508
 509	if (IS_ERR(data))
 510		return PTR_ERR(data);
 511
 512	mutex_lock(&data->update_lock);
 513	data->set_cnt = cnt_from_rpm(val, data->clk_freq,
 514				     G762_PULSE_FROM_REG(data->fan_cmd1),
 515				     G762_CLKDIV_FROM_REG(data->fan_cmd1),
 516				     G762_GEARMULT_FROM_REG(data->fan_cmd2));
 517	ret = i2c_smbus_write_byte_data(data->client, G762_REG_SET_CNT,
 518					data->set_cnt);
 519	data->valid = false;
 520	mutex_unlock(&data->update_lock);
 521
 522	return ret;
 523}
 524
 525/* Set fan startup voltage. Accepted values are either 0, 1, 2 or 3. */
 526static int do_set_fan_startv(struct device *dev, unsigned long val)
 527{
 528	struct g762_data *data = g762_update_client(dev);
 529	int ret;
 530
 531	if (IS_ERR(data))
 532		return PTR_ERR(data);
 533
 534	mutex_lock(&data->update_lock);
 535	switch (val) {
 536	case 0:
 537		data->fan_cmd2 &= ~G762_REG_FAN_CMD2_FAN_STARTV_0;
 538		data->fan_cmd2 &= ~G762_REG_FAN_CMD2_FAN_STARTV_1;
 539		break;
 540	case 1:
 541		data->fan_cmd2 |=  G762_REG_FAN_CMD2_FAN_STARTV_0;
 542		data->fan_cmd2 &= ~G762_REG_FAN_CMD2_FAN_STARTV_1;
 543		break;
 544	case 2:
 545		data->fan_cmd2 &= ~G762_REG_FAN_CMD2_FAN_STARTV_0;
 546		data->fan_cmd2 |=  G762_REG_FAN_CMD2_FAN_STARTV_1;
 547		break;
 548	case 3:
 549		data->fan_cmd2 |=  G762_REG_FAN_CMD2_FAN_STARTV_0;
 550		data->fan_cmd2 |=  G762_REG_FAN_CMD2_FAN_STARTV_1;
 551		break;
 552	default:
 553		ret = -EINVAL;
 554		goto out;
 555	}
 556	ret = i2c_smbus_write_byte_data(data->client, G762_REG_FAN_CMD2,
 557					data->fan_cmd2);
 558	data->valid = false;
 559 out:
 560	mutex_unlock(&data->update_lock);
 561
 562	return ret;
 563}
 564
 565/*
 566 * Helper to import hardware characteristics from .dts file and push
 567 * those to the chip.
 568 */
 569
 570#ifdef CONFIG_OF
 571static const struct of_device_id g762_dt_match[] = {
 572	{ .compatible = "gmt,g761" },
 573	{ .compatible = "gmt,g762" },
 574	{ .compatible = "gmt,g763" },
 575	{ },
 576};
 577MODULE_DEVICE_TABLE(of, g762_dt_match);
 578
 579/*
 580 * Grab clock (a required property), enable it, get (fixed) clock frequency
 581 * and store it. Note: upon success, clock has been prepared and enabled; it
 582 * must later be unprepared and disabled (e.g. during module unloading) by a
 583 * call to g762_of_clock_disable(). Note that a reference to clock is kept
 584 * in our private data structure to be used in this function.
 585 */
 586static void g762_of_clock_disable(void *data)
 587{
 588	struct g762_data *g762 = data;
 589
 590	clk_disable_unprepare(g762->clk);
 591	clk_put(g762->clk);
 592}
 593
 594static int g762_of_clock_enable(struct i2c_client *client)
 595{
 596	struct g762_data *data;
 597	unsigned long clk_freq;
 598	struct clk *clk;
 599	int ret;
 600
 601	if (!client->dev.of_node)
 602		return 0;
 603
 604	data = i2c_get_clientdata(client);
 605
 606	/*
 607	 * Skip CLK detection and handling if we use internal clock.
 608	 * This is only valid for g761.
 609	 */
 610	data->internal_clock = of_device_is_compatible(client->dev.of_node,
 611						       "gmt,g761") &&
 612			       !of_property_present(client->dev.of_node,
 613						    "clocks");
 614	if (data->internal_clock) {
 615		do_set_clk_freq(&client->dev, 32768);
 616		return 0;
 617	}
 618
 619	clk = of_clk_get(client->dev.of_node, 0);
 620	if (IS_ERR(clk)) {
 621		dev_err(&client->dev, "failed to get clock\n");
 622		return PTR_ERR(clk);
 623	}
 624
 625	ret = clk_prepare_enable(clk);
 626	if (ret) {
 627		dev_err(&client->dev, "failed to enable clock\n");
 628		goto clk_put;
 629	}
 630
 631	clk_freq = clk_get_rate(clk);
 632	ret = do_set_clk_freq(&client->dev, clk_freq);
 633	if (ret) {
 634		dev_err(&client->dev, "invalid clock freq %lu\n", clk_freq);
 635		goto clk_unprep;
 636	}
 637
 638	data->clk = clk;
 639
 640	ret = devm_add_action(&client->dev, g762_of_clock_disable, data);
 641	if (ret) {
 642		dev_err(&client->dev, "failed to add disable clock action\n");
 643		goto clk_unprep;
 644	}
 645
 646	return 0;
 647
 648 clk_unprep:
 649	clk_disable_unprepare(clk);
 650
 651 clk_put:
 652	clk_put(clk);
 653
 654	return ret;
 655}
 656
 657static int g762_of_prop_import_one(struct i2c_client *client,
 658				   const char *pname,
 659				   int (*psetter)(struct device *dev,
 660						  unsigned long val))
 661{
 662	int ret;
 663	u32 pval;
 664
 665	if (of_property_read_u32(client->dev.of_node, pname, &pval))
 666		return 0;
 667
 668	dev_dbg(&client->dev, "found %s (%d)\n", pname, pval);
 669	ret = (*psetter)(&client->dev, pval);
 670	if (ret)
 671		dev_err(&client->dev, "unable to set %s (%d)\n", pname, pval);
 672
 673	return ret;
 674}
 675
 676static int g762_of_prop_import(struct i2c_client *client)
 677{
 678	int ret;
 679
 680	if (!client->dev.of_node)
 681		return 0;
 682
 683	ret = g762_of_prop_import_one(client, "fan_gear_mode",
 684				      do_set_fan_gear_mode);
 685	if (ret)
 686		return ret;
 687
 688	ret = g762_of_prop_import_one(client, "pwm_polarity",
 689				      do_set_pwm_polarity);
 690	if (ret)
 691		return ret;
 692
 693	return g762_of_prop_import_one(client, "fan_startv",
 694				       do_set_fan_startv);
 695}
 696
 697#else
 698static int g762_of_prop_import(struct i2c_client *client)
 699{
 700	return 0;
 701}
 702
 703static int g762_of_clock_enable(struct i2c_client *client)
 704{
 705	return 0;
 706}
 707#endif
 708
 709/*
 710 * Helper to import hardware characteristics from .dts file and push
 711 * those to the chip.
 712 */
 713
 714static int g762_pdata_prop_import(struct i2c_client *client)
 715{
 716	struct g762_platform_data *pdata = dev_get_platdata(&client->dev);
 717	int ret;
 718
 719	if (!pdata)
 720		return 0;
 721
 722	ret = do_set_fan_gear_mode(&client->dev, pdata->fan_gear_mode);
 723	if (ret)
 724		return ret;
 725
 726	ret = do_set_pwm_polarity(&client->dev, pdata->pwm_polarity);
 727	if (ret)
 728		return ret;
 729
 730	ret = do_set_fan_startv(&client->dev, pdata->fan_startv);
 731	if (ret)
 732		return ret;
 733
 734	return do_set_clk_freq(&client->dev, pdata->clk_freq);
 735}
 736
 737/*
 738 * sysfs attributes
 739 */
 740
 741/*
 742 * Read function for fan1_input sysfs file. Return current fan RPM value, or
 743 * 0 if fan is out of control.
 744 */
 745static ssize_t fan1_input_show(struct device *dev,
 746			       struct device_attribute *da, char *buf)
 747{
 748	struct g762_data *data = g762_update_client(dev);
 749	unsigned int rpm = 0;
 750
 751	if (IS_ERR(data))
 752		return PTR_ERR(data);
 753
 754	mutex_lock(&data->update_lock);
 755	/* reverse logic: fan out of control reporting is enabled low */
 756	if (data->fan_sta & G762_REG_FAN_STA_OOC) {
 757		rpm = rpm_from_cnt(data->act_cnt, data->clk_freq,
 758				   G762_PULSE_FROM_REG(data->fan_cmd1),
 759				   G762_CLKDIV_FROM_REG(data->fan_cmd1),
 760				   G762_GEARMULT_FROM_REG(data->fan_cmd2));
 761	}
 762	mutex_unlock(&data->update_lock);
 763
 764	return sprintf(buf, "%u\n", rpm);
 765}
 766
 767/*
 768 * Read and write functions for pwm1_mode sysfs file. Get and set fan speed
 769 * control mode i.e. PWM (1) or DC (0).
 770 */
 771static ssize_t pwm1_mode_show(struct device *dev, struct device_attribute *da,
 772			      char *buf)
 773{
 774	struct g762_data *data = g762_update_client(dev);
 775
 776	if (IS_ERR(data))
 777		return PTR_ERR(data);
 778
 779	return sprintf(buf, "%d\n",
 780		       !!(data->fan_cmd1 & G762_REG_FAN_CMD1_OUT_MODE));
 781}
 782
 783static ssize_t pwm1_mode_store(struct device *dev,
 784			       struct device_attribute *da, const char *buf,
 785			       size_t count)
 786{
 787	unsigned long val;
 788	int ret;
 789
 790	if (kstrtoul(buf, 10, &val))
 791		return -EINVAL;
 792
 793	ret = do_set_pwm_mode(dev, val);
 794	if (ret < 0)
 795		return ret;
 796
 797	return count;
 798}
 799
 800/*
 801 * Read and write functions for fan1_div sysfs file. Get and set fan
 802 * controller prescaler value
 803 */
 804static ssize_t fan1_div_show(struct device *dev, struct device_attribute *da,
 805			     char *buf)
 806{
 807	struct g762_data *data = g762_update_client(dev);
 808
 809	if (IS_ERR(data))
 810		return PTR_ERR(data);
 811
 812	return sprintf(buf, "%d\n", G762_CLKDIV_FROM_REG(data->fan_cmd1));
 813}
 814
 815static ssize_t fan1_div_store(struct device *dev, struct device_attribute *da,
 816			      const char *buf, size_t count)
 817{
 818	unsigned long val;
 819	int ret;
 820
 821	if (kstrtoul(buf, 10, &val))
 822		return -EINVAL;
 823
 824	ret = do_set_fan_div(dev, val);
 825	if (ret < 0)
 826		return ret;
 827
 828	return count;
 829}
 830
 831/*
 832 * Read and write functions for fan1_pulses sysfs file. Get and set number
 833 * of tachometer pulses per fan revolution.
 834 */
 835static ssize_t fan1_pulses_show(struct device *dev,
 836				struct device_attribute *da, char *buf)
 837{
 838	struct g762_data *data = g762_update_client(dev);
 839
 840	if (IS_ERR(data))
 841		return PTR_ERR(data);
 842
 843	return sprintf(buf, "%d\n", G762_PULSE_FROM_REG(data->fan_cmd1));
 844}
 845
 846static ssize_t fan1_pulses_store(struct device *dev,
 847				 struct device_attribute *da, const char *buf,
 848				 size_t count)
 849{
 850	unsigned long val;
 851	int ret;
 852
 853	if (kstrtoul(buf, 10, &val))
 854		return -EINVAL;
 855
 856	ret = do_set_fan_pulses(dev, val);
 857	if (ret < 0)
 858		return ret;
 859
 860	return count;
 861}
 862
 863/*
 864 * Read and write functions for pwm1_enable. Get and set fan speed control mode
 865 * (i.e. closed or open-loop).
 866 *
 867 * Following documentation about hwmon's sysfs interface, a pwm1_enable node
 868 * should accept the following:
 869 *
 870 *  0 : no fan speed control (i.e. fan at full speed)
 871 *  1 : manual fan speed control enabled (use pwm[1-*]) (open-loop)
 872 *  2+: automatic fan speed control enabled (use fan[1-*]_target) (closed-loop)
 873 *
 874 * but we do not accept 0 as this mode is not natively supported by the chip
 875 * and it is not emulated by g762 driver. -EINVAL is returned in this case.
 876 */
 877static ssize_t pwm1_enable_show(struct device *dev,
 878				struct device_attribute *da, char *buf)
 879{
 880	struct g762_data *data = g762_update_client(dev);
 881
 882	if (IS_ERR(data))
 883		return PTR_ERR(data);
 884
 885	return sprintf(buf, "%d\n",
 886		       (!!(data->fan_cmd1 & G762_REG_FAN_CMD1_FAN_MODE)) + 1);
 887}
 888
 889static ssize_t pwm1_enable_store(struct device *dev,
 890				 struct device_attribute *da, const char *buf,
 891				 size_t count)
 892{
 893	unsigned long val;
 894	int ret;
 895
 896	if (kstrtoul(buf, 10, &val))
 897		return -EINVAL;
 898
 899	ret = do_set_pwm_enable(dev, val);
 900	if (ret < 0)
 901		return ret;
 902
 903	return count;
 904}
 905
 906/*
 907 * Read and write functions for pwm1 sysfs file. Get and set pwm value
 908 * (which affects fan speed) in open-loop mode. 0 stops the fan and 255
 909 * makes it run at full speed.
 910 */
 911static ssize_t pwm1_show(struct device *dev, struct device_attribute *da,
 912			 char *buf)
 913{
 914	struct g762_data *data = g762_update_client(dev);
 915
 916	if (IS_ERR(data))
 917		return PTR_ERR(data);
 918
 919	return sprintf(buf, "%d\n", data->set_out);
 920}
 921
 922static ssize_t pwm1_store(struct device *dev, struct device_attribute *da,
 923			  const char *buf, size_t count)
 924{
 925	unsigned long val;
 926	int ret;
 927
 928	if (kstrtoul(buf, 10, &val))
 929		return -EINVAL;
 930
 931	ret = do_set_pwm(dev, val);
 932	if (ret < 0)
 933		return ret;
 934
 935	return count;
 936}
 937
 938/*
 939 * Read and write function for fan1_target sysfs file. Get/set the fan speed in
 940 * closed-loop mode. Speed is given as a RPM value; then the chip will regulate
 941 * the fan speed using pulses from fan tachometer.
 942 *
 943 * Refer to rpm_from_cnt() implementation above to get info about count number
 944 * calculation.
 945 *
 946 * Also note that due to rounding errors it is possible that you don't read
 947 * back exactly the value you have set.
 948 */
 949static ssize_t fan1_target_show(struct device *dev,
 950				struct device_attribute *da, char *buf)
 951{
 952	struct g762_data *data = g762_update_client(dev);
 953	unsigned int rpm;
 954
 955	if (IS_ERR(data))
 956		return PTR_ERR(data);
 957
 958	mutex_lock(&data->update_lock);
 959	rpm = rpm_from_cnt(data->set_cnt, data->clk_freq,
 960			   G762_PULSE_FROM_REG(data->fan_cmd1),
 961			   G762_CLKDIV_FROM_REG(data->fan_cmd1),
 962			   G762_GEARMULT_FROM_REG(data->fan_cmd2));
 963	mutex_unlock(&data->update_lock);
 964
 965	return sprintf(buf, "%u\n", rpm);
 966}
 967
 968static ssize_t fan1_target_store(struct device *dev,
 969				 struct device_attribute *da, const char *buf,
 970				 size_t count)
 971{
 972	unsigned long val;
 973	int ret;
 974
 975	if (kstrtoul(buf, 10, &val))
 976		return -EINVAL;
 977
 978	ret = do_set_fan_target(dev, val);
 979	if (ret < 0)
 980		return ret;
 981
 982	return count;
 983}
 984
 985/* read function for fan1_fault sysfs file. */
 986static ssize_t fan1_fault_show(struct device *dev, struct device_attribute *da,
 987			       char *buf)
 988{
 989	struct g762_data *data = g762_update_client(dev);
 990
 991	if (IS_ERR(data))
 992		return PTR_ERR(data);
 993
 994	return sprintf(buf, "%u\n", !!(data->fan_sta & G762_REG_FAN_STA_FAIL));
 995}
 996
 997/*
 998 * read function for fan1_alarm sysfs file. Note that OOC condition is
 999 * enabled low
1000 */
1001static ssize_t fan1_alarm_show(struct device *dev,
1002			       struct device_attribute *da, char *buf)
1003{
1004	struct g762_data *data = g762_update_client(dev);
1005
1006	if (IS_ERR(data))
1007		return PTR_ERR(data);
1008
1009	return sprintf(buf, "%u\n", !(data->fan_sta & G762_REG_FAN_STA_OOC));
1010}
1011
1012static DEVICE_ATTR_RW(pwm1);
1013static DEVICE_ATTR_RW(pwm1_mode);
1014static DEVICE_ATTR_RW(pwm1_enable);
1015static DEVICE_ATTR_RO(fan1_input);
1016static DEVICE_ATTR_RO(fan1_alarm);
1017static DEVICE_ATTR_RO(fan1_fault);
1018static DEVICE_ATTR_RW(fan1_target);
1019static DEVICE_ATTR_RW(fan1_div);
1020static DEVICE_ATTR_RW(fan1_pulses);
1021
1022/* Driver data */
1023static struct attribute *g762_attrs[] = {
1024	&dev_attr_fan1_input.attr,
1025	&dev_attr_fan1_alarm.attr,
1026	&dev_attr_fan1_fault.attr,
1027	&dev_attr_fan1_target.attr,
1028	&dev_attr_fan1_div.attr,
1029	&dev_attr_fan1_pulses.attr,
1030	&dev_attr_pwm1.attr,
1031	&dev_attr_pwm1_mode.attr,
1032	&dev_attr_pwm1_enable.attr,
1033	NULL
1034};
1035
1036ATTRIBUTE_GROUPS(g762);
1037
1038/*
1039 * Enable both fan failure detection and fan out of control protection. The
1040 * function does not protect change/access to data structure; it must thus
1041 * only be called during initialization.
1042 */
1043static inline int g762_fan_init(struct device *dev)
1044{
1045	struct g762_data *data = g762_update_client(dev);
1046	int ret;
1047
1048	if (IS_ERR(data))
1049		return PTR_ERR(data);
1050
1051	/* internal_clock can only be set with compatible g761 */
1052	if (data->internal_clock)
1053		data->fan_cmd2 |= G761_REG_FAN_CMD2_FAN_CLOCK;
1054
1055	data->fan_cmd1 |= G762_REG_FAN_CMD1_DET_FAN_FAIL;
1056	data->fan_cmd1 |= G762_REG_FAN_CMD1_DET_FAN_OOC;
1057	data->valid = false;
1058
1059	ret = i2c_smbus_write_byte_data(data->client, G762_REG_FAN_CMD1,
1060					data->fan_cmd1);
1061	if (ret)
1062		return ret;
1063
1064	return i2c_smbus_write_byte_data(data->client, G762_REG_FAN_CMD2,
1065					 data->fan_cmd2);
1066}
1067
1068static int g762_probe(struct i2c_client *client)
1069{
1070	struct device *dev = &client->dev;
1071	struct device *hwmon_dev;
1072	struct g762_data *data;
1073	int ret;
1074
1075	if (!i2c_check_functionality(client->adapter,
1076				     I2C_FUNC_SMBUS_BYTE_DATA))
1077		return -ENODEV;
1078
1079	data = devm_kzalloc(dev, sizeof(struct g762_data), GFP_KERNEL);
1080	if (!data)
1081		return -ENOMEM;
1082
1083	i2c_set_clientdata(client, data);
1084	data->client = client;
1085	mutex_init(&data->update_lock);
1086
1087	/* Get configuration via DT ... */
1088	ret = g762_of_clock_enable(client);
1089	if (ret)
1090		return ret;
1091
1092	/* Enable fan failure detection and fan out of control protection */
1093	ret = g762_fan_init(dev);
1094	if (ret)
1095		return ret;
1096
1097	ret = g762_of_prop_import(client);
1098	if (ret)
1099		return ret;
1100	/* ... or platform_data */
1101	ret = g762_pdata_prop_import(client);
1102	if (ret)
1103		return ret;
1104
1105	hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
1106							    data, g762_groups);
1107	return PTR_ERR_OR_ZERO(hwmon_dev);
1108}
1109
1110static struct i2c_driver g762_driver = {
1111	.driver = {
1112		.name = DRVNAME,
1113		.of_match_table = of_match_ptr(g762_dt_match),
1114	},
1115	.probe = g762_probe,
1116	.id_table = g762_id,
1117};
1118
1119module_i2c_driver(g762_driver);
1120
1121MODULE_AUTHOR("Arnaud EBALARD <arno@natisbad.org>");
1122MODULE_DESCRIPTION("GMT G762/G763 driver");
1123MODULE_LICENSE("GPL");