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