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