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1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Hardware monitoring driver for EMC2305 fan controller
4 *
5 * Copyright (C) 2022 Nvidia Technologies Ltd.
6 */
7
8#include <linux/err.h>
9#include <linux/hwmon.h>
10#include <linux/i2c.h>
11#include <linux/module.h>
12#include <linux/platform_data/emc2305.h>
13#include <linux/thermal.h>
14#include <linux/pwm.h>
15#include <linux/of_device.h>
16#include <linux/util_macros.h>
17
18#define EMC2305_REG_DRIVE_FAIL_STATUS 0x27
19#define EMC2305_REG_VENDOR 0xfe
20#define EMC2305_FAN_MAX 0xff
21#define EMC2305_FAN_MIN 0x00
22#define EMC2305_FAN_MAX_STATE 10
23#define EMC2305_DEVICE 0x34
24#define EMC2305_VENDOR 0x5d
25#define EMC2305_REG_PRODUCT_ID 0xfd
26#define EMC2305_TACH_REGS_UNUSE_BITS 3
27#define EMC2305_TACH_CNT_MULTIPLIER 0x02
28#define EMC2305_TACH_RANGE_MIN 480
29#define EMC2305_DEFAULT_OUTPUT 0x0
30#define EMC2305_DEFAULT_POLARITY 0x0
31#define EMC2305_REG_POLARITY 0x2a
32#define EMC2305_REG_DRIVE_PWM_OUT 0x2b
33#define EMC2305_OPEN_DRAIN 0x0
34#define EMC2305_PUSH_PULL 0x1
35#define EMC2305_PWM_SHUTDOWN_UNSET -1
36
37#define EMC2305_PWM_DUTY2STATE(duty, max_state, pwm_max) \
38 DIV_ROUND_CLOSEST((duty) * (max_state), (pwm_max))
39#define EMC2305_PWM_STATE2DUTY(state, max_state, pwm_max) \
40 DIV_ROUND_CLOSEST((state) * (pwm_max), (max_state))
41
42/*
43 * Factor by equations [2] and [3] from data sheet; valid for fans where the number of edges
44 * equal (poles * 2 + 1).
45 */
46#define EMC2305_RPM_FACTOR 3932160
47
48#define EMC2305_REG_FAN_DRIVE(n) (0x30 + 0x10 * (n))
49#define EMC2305_REG_FAN_MIN_DRIVE(n) (0x38 + 0x10 * (n))
50#define EMC2305_REG_FAN_TACH(n) (0x3e + 0x10 * (n))
51
52/* Supported base PWM frequencies */
53static const unsigned int base_freq_table[] = { 2441, 4882, 19530, 26000 };
54
55enum emc230x_product_id {
56 EMC2305 = 0x34,
57 EMC2303 = 0x35,
58 EMC2302 = 0x36,
59 EMC2301 = 0x37,
60};
61
62static const struct i2c_device_id emc2305_ids[] = {
63 { .name = "emc2305" },
64 { .name = "emc2303" },
65 { .name = "emc2302" },
66 { .name = "emc2301" },
67 { }
68};
69MODULE_DEVICE_TABLE(i2c, emc2305_ids);
70
71/**
72 * struct emc2305_cdev_data - device-specific cooling device state
73 * @cdev: cooling device
74 * @cur_state: cooling current state
75 * @last_hwmon_state: last cooling state updated by hwmon subsystem
76 * @last_thermal_state: last cooling state updated by thermal subsystem
77 *
78 * The 'last_hwmon_state' and 'last_thermal_state' fields are provided to support fan low limit
79 * speed feature. The purpose of this feature is to provides ability to limit fan speed
80 * according to some system wise considerations, like absence of some replaceable units (PSU or
81 * line cards), high system ambient temperature, unreliable transceivers temperature sensing or
82 * some other factors which indirectly impacts system's airflow
83 * Fan low limit feature is supported through 'hwmon' interface: 'hwmon' 'pwm' attribute is
84 * used for setting low limit for fan speed in case 'thermal' subsystem is configured in
85 * kernel. In this case setting fan speed through 'hwmon' will never let the 'thermal'
86 * subsystem to select a lower duty cycle than the duty cycle selected with the 'pwm'
87 * attribute.
88 * From other side, fan speed is to be updated in hardware through 'pwm' only in case the
89 * requested fan speed is above last speed set by 'thermal' subsystem, otherwise requested fan
90 * speed will be just stored with no PWM update.
91 */
92struct emc2305_cdev_data {
93 struct thermal_cooling_device *cdev;
94 unsigned int cur_state;
95 unsigned long last_hwmon_state;
96 unsigned long last_thermal_state;
97};
98
99/**
100 * struct emc2305_data - device-specific data
101 * @client: i2c client
102 * @hwmon_dev: hwmon device
103 * @max_state: maximum cooling state of the cooling device
104 * @pwm_num: number of PWM channels
105 * @pwm_output_mask: PWM output mask
106 * @pwm_polarity_mask: PWM polarity mask
107 * @pwm_separate: separate PWM settings for every channel
108 * @pwm_shutdown: Set shutdown PWM.
109 * @pwm_min: array of minimum PWM per channel
110 * @pwm_freq: array of PWM frequency per channel
111 * @cdev_data: array of cooling devices data
112 */
113struct emc2305_data {
114 struct i2c_client *client;
115 struct device *hwmon_dev;
116 u8 max_state;
117 u8 pwm_num;
118 u8 pwm_output_mask;
119 u8 pwm_polarity_mask;
120 bool pwm_separate;
121 s16 pwm_shutdown[EMC2305_PWM_MAX];
122 u8 pwm_min[EMC2305_PWM_MAX];
123 u16 pwm_freq[EMC2305_PWM_MAX];
124 struct emc2305_cdev_data cdev_data[EMC2305_PWM_MAX];
125};
126
127static char *emc2305_fan_name[] = {
128 "emc2305_fan",
129 "emc2305_fan1",
130 "emc2305_fan2",
131 "emc2305_fan3",
132 "emc2305_fan4",
133 "emc2305_fan5",
134};
135
136static int emc2305_get_max_channel(const struct emc2305_data *data)
137{
138 return data->pwm_num;
139}
140
141static int emc2305_get_cdev_idx(struct thermal_cooling_device *cdev)
142{
143 struct emc2305_data *data = cdev->devdata;
144 size_t len = strlen(cdev->type);
145 int ret;
146
147 if (len <= 0)
148 return -EINVAL;
149
150 /*
151 * Returns index of cooling device 0..4 in case of separate PWM setting.
152 * Zero index is used in case of one common PWM setting.
153 * If the mode is not set as pwm_separate, all PWMs are to be bound
154 * to the common thermal zone and should work at the same speed
155 * to perform cooling for the same thermal junction.
156 * Otherwise, return specific channel that will be used in bound
157 * related PWM to the thermal zone.
158 */
159 if (!data->pwm_separate)
160 return 0;
161
162 ret = cdev->type[len - 1];
163 switch (ret) {
164 case '1' ... '5':
165 return ret - '1';
166 default:
167 break;
168 }
169 return -EINVAL;
170}
171
172static int emc2305_get_cur_state(struct thermal_cooling_device *cdev, unsigned long *state)
173{
174 int cdev_idx;
175 struct emc2305_data *data = cdev->devdata;
176
177 cdev_idx = emc2305_get_cdev_idx(cdev);
178 if (cdev_idx < 0)
179 return cdev_idx;
180
181 *state = data->cdev_data[cdev_idx].cur_state;
182 return 0;
183}
184
185static int emc2305_get_max_state(struct thermal_cooling_device *cdev, unsigned long *state)
186{
187 struct emc2305_data *data = cdev->devdata;
188 *state = data->max_state;
189 return 0;
190}
191
192static int __emc2305_set_cur_state(struct emc2305_data *data, int cdev_idx, unsigned long state)
193{
194 int ret;
195 struct i2c_client *client = data->client;
196 u8 val, i;
197
198 state = max_t(unsigned long, state, data->cdev_data[cdev_idx].last_hwmon_state);
199
200 val = EMC2305_PWM_STATE2DUTY(state, data->max_state, EMC2305_FAN_MAX);
201
202 data->cdev_data[cdev_idx].cur_state = state;
203 if (data->pwm_separate) {
204 ret = i2c_smbus_write_byte_data(client, EMC2305_REG_FAN_DRIVE(cdev_idx), val);
205 if (ret < 0)
206 return ret;
207 } else {
208 /*
209 * Set the same PWM value in all channels
210 * if common PWM channel is used.
211 */
212 for (i = 0; i < data->pwm_num; i++) {
213 ret = i2c_smbus_write_byte_data(client, EMC2305_REG_FAN_DRIVE(i), val);
214 if (ret < 0)
215 return ret;
216 }
217 }
218
219 return 0;
220}
221
222static int emc2305_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state)
223{
224 int cdev_idx, ret;
225 struct emc2305_data *data = cdev->devdata;
226
227 if (state > data->max_state)
228 return -EINVAL;
229
230 cdev_idx = emc2305_get_cdev_idx(cdev);
231 if (cdev_idx < 0)
232 return cdev_idx;
233
234 /* Save thermal state. */
235 data->cdev_data[cdev_idx].last_thermal_state = state;
236 ret = __emc2305_set_cur_state(data, cdev_idx, state);
237 if (ret < 0)
238 return ret;
239
240 return 0;
241}
242
243static const struct thermal_cooling_device_ops emc2305_cooling_ops = {
244 .get_max_state = emc2305_get_max_state,
245 .get_cur_state = emc2305_get_cur_state,
246 .set_cur_state = emc2305_set_cur_state,
247};
248
249static int emc2305_show_fault(struct device *dev, int channel)
250{
251 struct emc2305_data *data = dev_get_drvdata(dev);
252 struct i2c_client *client = data->client;
253 int status_reg;
254
255 status_reg = i2c_smbus_read_byte_data(client, EMC2305_REG_DRIVE_FAIL_STATUS);
256 if (status_reg < 0)
257 return status_reg;
258
259 return status_reg & (1 << channel) ? 1 : 0;
260}
261
262static int emc2305_show_fan(struct device *dev, int channel)
263{
264 struct emc2305_data *data = dev_get_drvdata(dev);
265 struct i2c_client *client = data->client;
266 int ret;
267
268 ret = i2c_smbus_read_word_swapped(client, EMC2305_REG_FAN_TACH(channel));
269 if (ret <= 0)
270 return ret;
271
272 ret = ret >> EMC2305_TACH_REGS_UNUSE_BITS;
273 ret = EMC2305_RPM_FACTOR / ret;
274 if (ret <= EMC2305_TACH_RANGE_MIN)
275 return 0;
276
277 return ret * EMC2305_TACH_CNT_MULTIPLIER;
278}
279
280static int emc2305_show_pwm(struct device *dev, int channel)
281{
282 struct emc2305_data *data = dev_get_drvdata(dev);
283 struct i2c_client *client = data->client;
284
285 return i2c_smbus_read_byte_data(client, EMC2305_REG_FAN_DRIVE(channel));
286}
287
288static int emc2305_set_pwm(struct device *dev, long val, int channel)
289{
290 struct emc2305_data *data = dev_get_drvdata(dev);
291 struct i2c_client *client = data->client;
292 int ret;
293
294 if (val < data->pwm_min[channel] || val > EMC2305_FAN_MAX)
295 return -EINVAL;
296
297 ret = i2c_smbus_write_byte_data(client, EMC2305_REG_FAN_DRIVE(channel), val);
298 if (ret < 0)
299 return ret;
300 data->cdev_data[channel].cur_state = EMC2305_PWM_DUTY2STATE(val, data->max_state,
301 EMC2305_FAN_MAX);
302 return 0;
303}
304
305static int emc2305_set_single_tz(struct device *dev, struct device_node *fan_node, int idx)
306{
307 struct emc2305_data *data = dev_get_drvdata(dev);
308 long pwm;
309 int i, cdev_idx, ret;
310
311 cdev_idx = (idx) ? idx - 1 : 0;
312 pwm = data->pwm_min[cdev_idx];
313
314 data->cdev_data[cdev_idx].cdev =
315 devm_thermal_of_child_cooling_device_register(dev, fan_node,
316 emc2305_fan_name[idx], data,
317 &emc2305_cooling_ops);
318
319 if (IS_ERR(data->cdev_data[cdev_idx].cdev)) {
320 dev_err(dev, "Failed to register cooling device %s\n", emc2305_fan_name[idx]);
321 return PTR_ERR(data->cdev_data[cdev_idx].cdev);
322 }
323
324 if (data->cdev_data[cdev_idx].cur_state > 0)
325 /* Update pwm when temperature is above trips */
326 pwm = EMC2305_PWM_STATE2DUTY(data->cdev_data[cdev_idx].cur_state,
327 data->max_state, EMC2305_FAN_MAX);
328
329 /* Set minimal PWM speed. */
330 if (data->pwm_separate) {
331 ret = emc2305_set_pwm(dev, pwm, cdev_idx);
332 if (ret < 0)
333 return ret;
334 } else {
335 for (i = 0; i < data->pwm_num; i++) {
336 ret = emc2305_set_pwm(dev, pwm, i);
337 if (ret < 0)
338 return ret;
339 }
340 }
341 data->cdev_data[cdev_idx].cur_state =
342 EMC2305_PWM_DUTY2STATE(pwm, data->max_state,
343 EMC2305_FAN_MAX);
344 data->cdev_data[cdev_idx].last_hwmon_state =
345 EMC2305_PWM_DUTY2STATE(pwm, data->max_state,
346 EMC2305_FAN_MAX);
347 return 0;
348}
349
350static int emc2305_set_tz(struct device *dev)
351{
352 struct emc2305_data *data = dev_get_drvdata(dev);
353 int i, ret;
354
355 if (!data->pwm_separate)
356 return emc2305_set_single_tz(dev, dev->of_node, 0);
357
358 for (i = 0; i < data->pwm_num; i++) {
359 ret = emc2305_set_single_tz(dev, dev->of_node, i + 1);
360 if (ret)
361 return ret;
362 }
363 return 0;
364}
365
366static umode_t
367emc2305_is_visible(const void *data, enum hwmon_sensor_types type, u32 attr, int channel)
368{
369 int max_channel = emc2305_get_max_channel(data);
370
371 /* Don't show channels which are not physically connected. */
372 if (channel >= max_channel)
373 return 0;
374 switch (type) {
375 case hwmon_fan:
376 switch (attr) {
377 case hwmon_fan_input:
378 return 0444;
379 case hwmon_fan_fault:
380 return 0444;
381 default:
382 break;
383 }
384 break;
385 case hwmon_pwm:
386 switch (attr) {
387 case hwmon_pwm_input:
388 return 0644;
389 default:
390 break;
391 }
392 break;
393 default:
394 break;
395 }
396
397 return 0;
398};
399
400static int
401emc2305_write(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel, long val)
402{
403 struct emc2305_data *data = dev_get_drvdata(dev);
404 int cdev_idx;
405
406 switch (type) {
407 case hwmon_pwm:
408 switch (attr) {
409 case hwmon_pwm_input:
410 /* If thermal is configured - handle PWM limit setting. */
411 if (IS_REACHABLE(CONFIG_THERMAL)) {
412 if (data->pwm_separate)
413 cdev_idx = channel;
414 else
415 cdev_idx = 0;
416 data->cdev_data[cdev_idx].last_hwmon_state =
417 EMC2305_PWM_DUTY2STATE(val, data->max_state,
418 EMC2305_FAN_MAX);
419 /*
420 * Update PWM only in case requested state is not less than the
421 * last thermal state.
422 */
423 if (data->cdev_data[cdev_idx].last_hwmon_state >=
424 data->cdev_data[cdev_idx].last_thermal_state)
425 return __emc2305_set_cur_state(data, cdev_idx,
426 data->cdev_data[cdev_idx].last_hwmon_state);
427 return 0;
428 }
429 return emc2305_set_pwm(dev, val, channel);
430 default:
431 break;
432 }
433 break;
434 default:
435 break;
436 }
437
438 return -EOPNOTSUPP;
439};
440
441static int
442emc2305_read(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel, long *val)
443{
444 int ret;
445
446 switch (type) {
447 case hwmon_fan:
448 switch (attr) {
449 case hwmon_fan_input:
450 ret = emc2305_show_fan(dev, channel);
451 if (ret < 0)
452 return ret;
453 *val = ret;
454 return 0;
455 case hwmon_fan_fault:
456 ret = emc2305_show_fault(dev, channel);
457 if (ret < 0)
458 return ret;
459 *val = ret;
460 return 0;
461 default:
462 break;
463 }
464 break;
465 case hwmon_pwm:
466 switch (attr) {
467 case hwmon_pwm_input:
468 ret = emc2305_show_pwm(dev, channel);
469 if (ret < 0)
470 return ret;
471 *val = ret;
472 return 0;
473 default:
474 break;
475 }
476 break;
477 default:
478 break;
479 }
480
481 return -EOPNOTSUPP;
482};
483
484static const struct hwmon_ops emc2305_ops = {
485 .is_visible = emc2305_is_visible,
486 .read = emc2305_read,
487 .write = emc2305_write,
488};
489
490static const struct hwmon_channel_info * const emc2305_info[] = {
491 HWMON_CHANNEL_INFO(fan,
492 HWMON_F_INPUT | HWMON_F_FAULT,
493 HWMON_F_INPUT | HWMON_F_FAULT,
494 HWMON_F_INPUT | HWMON_F_FAULT,
495 HWMON_F_INPUT | HWMON_F_FAULT,
496 HWMON_F_INPUT | HWMON_F_FAULT),
497 HWMON_CHANNEL_INFO(pwm,
498 HWMON_PWM_INPUT,
499 HWMON_PWM_INPUT,
500 HWMON_PWM_INPUT,
501 HWMON_PWM_INPUT,
502 HWMON_PWM_INPUT),
503 NULL
504};
505
506static const struct hwmon_chip_info emc2305_chip_info = {
507 .ops = &emc2305_ops,
508 .info = emc2305_info,
509};
510
511static int emc2305_identify(struct device *dev)
512{
513 struct i2c_client *client = to_i2c_client(dev);
514 struct emc2305_data *data = i2c_get_clientdata(client);
515 int ret;
516
517 ret = i2c_smbus_read_byte_data(client, EMC2305_REG_PRODUCT_ID);
518 if (ret < 0)
519 return ret;
520
521 switch (ret) {
522 case EMC2305:
523 data->pwm_num = 5;
524 break;
525 case EMC2303:
526 data->pwm_num = 3;
527 break;
528 case EMC2302:
529 data->pwm_num = 2;
530 break;
531 case EMC2301:
532 data->pwm_num = 1;
533 break;
534 default:
535 return -ENODEV;
536 }
537
538 return 0;
539}
540
541static int emc2305_of_parse_pwm_child(struct device *dev,
542 struct device_node *child,
543 struct emc2305_data *data)
544{ u32 ch;
545 u32 pwm_shutdown_percent;
546 int ret;
547 struct of_phandle_args args;
548
549 ret = of_property_read_u32(child, "reg", &ch);
550 if (ret) {
551 dev_err(dev, "missing reg property of %pOFn\n", child);
552 return ret;
553 }
554
555 if (ch >= data->pwm_num) {
556 dev_err(dev, "invalid reg %u for node %pOF (valid range 0-%u)\n", ch, child,
557 data->pwm_num - 1);
558 return -EINVAL;
559 }
560
561 ret = of_parse_phandle_with_args(child, "pwms", "#pwm-cells", 0, &args);
562
563 if (ret)
564 return ret;
565
566 if (args.args_count > 0) {
567 data->pwm_freq[ch] = find_closest(args.args[0], base_freq_table,
568 ARRAY_SIZE(base_freq_table));
569 } else {
570 data->pwm_freq[ch] = base_freq_table[3];
571 }
572
573 if (args.args_count > 1) {
574 if (args.args[1] == PWM_POLARITY_NORMAL || args.args[1] == PWM_POLARITY_INVERSED)
575 data->pwm_polarity_mask |= args.args[1] << ch;
576 else
577 dev_err(dev, "Wrong PWM polarity config provided: %d\n", args.args[0]);
578 } else {
579 data->pwm_polarity_mask |= PWM_POLARITY_NORMAL << ch;
580 }
581
582 if (args.args_count > 2) {
583 if (args.args[2] == EMC2305_PUSH_PULL || args.args[2] <= EMC2305_OPEN_DRAIN)
584 data->pwm_output_mask |= args.args[2] << ch;
585 else
586 dev_err(dev, "Wrong PWM output config provided: %d\n", args.args[1]);
587 } else {
588 data->pwm_output_mask |= EMC2305_OPEN_DRAIN << ch;
589 }
590
591 of_node_put(args.np);
592
593 ret = of_property_read_u32(child, "fan-shutdown-percent",
594 &pwm_shutdown_percent);
595
596 if (!ret) {
597 pwm_shutdown_percent = clamp(pwm_shutdown_percent, 0, 100);
598 data->pwm_shutdown[ch] =
599 DIV_ROUND_CLOSEST(pwm_shutdown_percent * EMC2305_FAN_MAX, 100);
600 }
601
602 return 0;
603}
604
605static int emc2305_probe_childs_from_dt(struct device *dev)
606{
607 struct emc2305_data *data = dev_get_drvdata(dev);
608 struct device_node *child;
609 int ret, count = 0;
610
611 data->pwm_output_mask = 0x0;
612 data->pwm_polarity_mask = 0x0;
613
614 for_each_child_of_node(dev->of_node, child) {
615 if (of_property_present(child, "reg")) {
616 ret = emc2305_of_parse_pwm_child(dev, child, data);
617 if (ret)
618 continue;
619 count++;
620 }
621 }
622 return count;
623}
624
625static int emc2305_probe(struct i2c_client *client)
626{
627 struct i2c_adapter *adapter = client->adapter;
628 struct device *dev = &client->dev;
629 struct emc2305_data *data;
630 struct emc2305_platform_data *pdata;
631 int vendor;
632 int ret;
633 int i;
634 int pwm_childs;
635 u32 ch;
636
637 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA))
638 return -ENODEV;
639
640 vendor = i2c_smbus_read_byte_data(client, EMC2305_REG_VENDOR);
641 if (vendor != EMC2305_VENDOR)
642 return -ENODEV;
643
644 data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
645 if (!data)
646 return -ENOMEM;
647
648 i2c_set_clientdata(client, data);
649 data->client = client;
650
651 ret = emc2305_identify(dev);
652 if (ret)
653 return ret;
654
655 for (i = 0; i < EMC2305_PWM_MAX; i++)
656 data->pwm_shutdown[i] = EMC2305_PWM_SHUTDOWN_UNSET;
657
658 pwm_childs = emc2305_probe_childs_from_dt(dev);
659
660 pdata = dev_get_platdata(&client->dev);
661
662 if (!pwm_childs) {
663 if (pdata) {
664 if (!pdata->max_state || pdata->max_state > EMC2305_FAN_MAX_STATE)
665 return -EINVAL;
666 data->max_state = pdata->max_state;
667 /*
668 * Validate a number of active PWM channels. Note that
669 * configured number can be less than the actual maximum
670 * supported by the device.
671 */
672 if (!pdata->pwm_num || pdata->pwm_num > EMC2305_PWM_MAX)
673 return -EINVAL;
674 data->pwm_num = pdata->pwm_num;
675 data->pwm_output_mask = pdata->pwm_output_mask;
676 data->pwm_polarity_mask = pdata->pwm_polarity_mask;
677 data->pwm_separate = pdata->pwm_separate;
678 for (i = 0; i < EMC2305_PWM_MAX; i++) {
679 data->pwm_min[i] = pdata->pwm_min[i];
680 data->pwm_freq[i] = pdata->pwm_freq[i];
681 }
682 } else {
683 data->max_state = EMC2305_FAN_MAX_STATE;
684 data->pwm_separate = false;
685 data->pwm_output_mask = EMC2305_DEFAULT_OUTPUT;
686 data->pwm_polarity_mask = EMC2305_DEFAULT_POLARITY;
687 for (i = 0; i < EMC2305_PWM_MAX; i++) {
688 data->pwm_min[i] = EMC2305_FAN_MIN;
689 data->pwm_freq[i] = base_freq_table[3];
690 }
691 }
692 } else {
693 data->max_state = EMC2305_FAN_MAX_STATE;
694 data->pwm_separate = false;
695 for (i = 0; i < EMC2305_PWM_MAX; i++)
696 data->pwm_min[i] = EMC2305_FAN_MIN;
697 }
698
699 data->hwmon_dev = devm_hwmon_device_register_with_info(dev, "emc2305", data,
700 &emc2305_chip_info, NULL);
701 if (IS_ERR(data->hwmon_dev))
702 return PTR_ERR(data->hwmon_dev);
703
704 if (IS_REACHABLE(CONFIG_THERMAL)) {
705 /* Parse and check for the available PWM child nodes */
706 if (pwm_childs > 0) {
707 for_each_child_of_node_scoped(dev->of_node, child) {
708 ret = of_property_read_u32(child, "reg", &ch);
709 if (ret || ch >= data->pwm_num)
710 continue;
711
712 /*
713 * emc2305_set_single_tz() uses 0 for the common cooling
714 * device and 1..pwm_num for individual fan channels.
715 */
716 ret = emc2305_set_single_tz(dev, child, ch + 1);
717 if (ret != 0)
718 return ret;
719 }
720 } else {
721 ret = emc2305_set_tz(dev);
722 if (ret != 0)
723 return ret;
724 }
725 }
726
727 ret = i2c_smbus_write_byte_data(client, EMC2305_REG_DRIVE_PWM_OUT,
728 data->pwm_output_mask);
729 if (ret < 0)
730 dev_err(dev, "Failed to configure pwm output, using default\n");
731
732 ret = i2c_smbus_write_byte_data(client, EMC2305_REG_POLARITY,
733 data->pwm_polarity_mask);
734 if (ret < 0)
735 dev_err(dev, "Failed to configure pwm polarity, using default\n");
736
737 for (i = 0; i < data->pwm_num; i++) {
738 ret = i2c_smbus_write_byte_data(client, EMC2305_REG_FAN_MIN_DRIVE(i),
739 data->pwm_min[i]);
740 if (ret < 0)
741 return ret;
742 }
743
744 return 0;
745}
746
747static void emc2305_shutdown(struct i2c_client *client)
748{
749 int i;
750 int ret;
751 struct emc2305_data *data = i2c_get_clientdata(client);
752
753 for (i = 0; i < data->pwm_num; i++) {
754 if (data->pwm_shutdown[i] != EMC2305_PWM_SHUTDOWN_UNSET) {
755 ret = i2c_smbus_write_byte_data(client, EMC2305_REG_FAN_DRIVE(i),
756 data->pwm_shutdown[i]);
757 if (ret < 0)
758 dev_warn(&client->dev,
759 "Failed to set shutdown PWM for ch %d\n", i);
760 }
761 }
762}
763
764static const struct of_device_id of_emc2305_match_table[] = {
765 { .compatible = "microchip,emc2305", },
766 {},
767};
768MODULE_DEVICE_TABLE(of, of_emc2305_match_table);
769
770static struct i2c_driver emc2305_driver = {
771 .driver = {
772 .name = "emc2305",
773 .of_match_table = of_emc2305_match_table,
774 },
775 .probe = emc2305_probe,
776 .shutdown = emc2305_shutdown,
777 .id_table = emc2305_ids,
778};
779
780module_i2c_driver(emc2305_driver);
781
782MODULE_AUTHOR("Nvidia");
783MODULE_DESCRIPTION("Microchip EMC2305 fan controller driver");
784MODULE_LICENSE("GPL");