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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * pwm-fan.c - Hwmon driver for fans connected to PWM lines.
4 *
5 * Copyright (c) 2014 Samsung Electronics Co., Ltd.
6 *
7 * Author: Kamil Debski <[email protected]>
8 */
9
10#include <linux/delay.h>
11#include <linux/hwmon.h>
12#include <linux/interrupt.h>
13#include <linux/module.h>
14#include <linux/mutex.h>
15#include <linux/platform_device.h>
16#include <linux/property.h>
17#include <linux/pwm.h>
18#include <linux/regulator/consumer.h>
19#include <linux/sysfs.h>
20#include <linux/thermal.h>
21#include <linux/timer.h>
22
23#define MAX_PWM 255
24
25struct pwm_fan_tach {
26 int irq;
27 atomic_t pulses;
28 unsigned int rpm;
29};
30
31enum pwm_fan_enable_mode {
32 pwm_off_reg_off,
33 pwm_disable_reg_enable,
34 pwm_enable_reg_enable,
35 pwm_disable_reg_disable,
36};
37
38struct pwm_fan_ctx {
39 struct device *dev;
40
41 struct mutex lock;
42 struct pwm_device *pwm;
43 struct pwm_state pwm_state;
44 struct regulator *reg_en;
45 enum pwm_fan_enable_mode enable_mode;
46 bool regulator_enabled;
47 bool enabled;
48
49 int tach_count;
50 struct pwm_fan_tach *tachs;
51 u32 *pulses_per_revolution;
52 ktime_t sample_start;
53 struct timer_list rpm_timer;
54
55 unsigned int pwm_value;
56 unsigned int pwm_fan_state;
57 unsigned int pwm_fan_max_state;
58 unsigned int *pwm_fan_cooling_levels;
59 struct thermal_cooling_device *cdev;
60
61 struct hwmon_chip_info info;
62 struct hwmon_channel_info fan_channel;
63
64 u64 pwm_duty_cycle_from_stopped;
65 u32 pwm_usec_from_stopped;
66 u8 pwm_shutdown;
67};
68
69/* This handler assumes self resetting edge triggered interrupt. */
70static irqreturn_t pulse_handler(int irq, void *dev_id)
71{
72 struct pwm_fan_tach *tach = dev_id;
73
74 atomic_inc(&tach->pulses);
75
76 return IRQ_HANDLED;
77}
78
79static void sample_timer(struct timer_list *t)
80{
81 struct pwm_fan_ctx *ctx = timer_container_of(ctx, t, rpm_timer);
82 unsigned int delta = ktime_ms_delta(ktime_get(), ctx->sample_start);
83 int i;
84
85 if (delta) {
86 for (i = 0; i < ctx->tach_count; i++) {
87 struct pwm_fan_tach *tach = &ctx->tachs[i];
88 int pulses;
89
90 pulses = atomic_read(&tach->pulses);
91 atomic_sub(pulses, &tach->pulses);
92 tach->rpm = (unsigned int)(pulses * 1000 * 60) /
93 (ctx->pulses_per_revolution[i] * delta);
94 }
95
96 ctx->sample_start = ktime_get();
97 }
98
99 mod_timer(&ctx->rpm_timer, jiffies + HZ);
100}
101
102static void pwm_fan_enable_mode_2_state(int enable_mode,
103 struct pwm_state *state,
104 bool *enable_regulator)
105{
106 switch (enable_mode) {
107 case pwm_disable_reg_enable:
108 /* disable pwm, keep regulator enabled */
109 state->enabled = false;
110 *enable_regulator = true;
111 break;
112 case pwm_enable_reg_enable:
113 /* keep pwm and regulator enabled */
114 state->enabled = true;
115 *enable_regulator = true;
116 break;
117 case pwm_off_reg_off:
118 case pwm_disable_reg_disable:
119 /* disable pwm and regulator */
120 state->enabled = false;
121 *enable_regulator = false;
122 }
123}
124
125static int pwm_fan_switch_power(struct pwm_fan_ctx *ctx, bool on)
126{
127 int ret = 0;
128
129 if (!ctx->reg_en)
130 return ret;
131
132 if (!ctx->regulator_enabled && on) {
133 ret = regulator_enable(ctx->reg_en);
134 if (ret == 0)
135 ctx->regulator_enabled = true;
136 } else if (ctx->regulator_enabled && !on) {
137 ret = regulator_disable(ctx->reg_en);
138 if (ret == 0)
139 ctx->regulator_enabled = false;
140 }
141 return ret;
142}
143
144static int pwm_fan_power_on(struct pwm_fan_ctx *ctx)
145{
146 struct pwm_state *state = &ctx->pwm_state;
147 int ret;
148
149 if (ctx->enabled)
150 return 0;
151
152 ret = pwm_fan_switch_power(ctx, true);
153 if (ret < 0) {
154 dev_err(ctx->dev, "failed to enable power supply\n");
155 return ret;
156 }
157
158 state->enabled = true;
159 ret = pwm_apply_might_sleep(ctx->pwm, state);
160 if (ret) {
161 dev_err(ctx->dev, "failed to enable PWM\n");
162 goto disable_regulator;
163 }
164
165 ctx->enabled = true;
166
167 return 0;
168
169disable_regulator:
170 pwm_fan_switch_power(ctx, false);
171 return ret;
172}
173
174static int pwm_fan_power_off(struct pwm_fan_ctx *ctx, bool force_disable)
175{
176 struct pwm_state *state = &ctx->pwm_state;
177 bool enable_regulator = false;
178 int ret;
179
180 if (!ctx->enabled)
181 return 0;
182
183 pwm_fan_enable_mode_2_state(ctx->enable_mode,
184 state,
185 &enable_regulator);
186
187 if (force_disable)
188 state->enabled = false;
189 state->duty_cycle = 0;
190 ret = pwm_apply_might_sleep(ctx->pwm, state);
191 if (ret) {
192 dev_err(ctx->dev, "failed to disable PWM\n");
193 return ret;
194 }
195
196 pwm_fan_switch_power(ctx, enable_regulator);
197
198 ctx->enabled = false;
199
200 return 0;
201}
202
203static int __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm)
204{
205 struct pwm_state *state = &ctx->pwm_state;
206 unsigned long final_pwm = pwm;
207 unsigned long period;
208 bool update = false;
209 int ret = 0;
210
211 if (pwm > 0) {
212 if (ctx->enable_mode == pwm_off_reg_off)
213 /* pwm-fan hard disabled */
214 return 0;
215
216 period = state->period;
217 update = state->duty_cycle < ctx->pwm_duty_cycle_from_stopped;
218 if (update)
219 state->duty_cycle = ctx->pwm_duty_cycle_from_stopped;
220 else
221 state->duty_cycle = DIV_ROUND_UP(pwm * (period - 1), MAX_PWM);
222 ret = pwm_apply_might_sleep(ctx->pwm, state);
223 if (ret)
224 return ret;
225 ret = pwm_fan_power_on(ctx);
226 if (!ret && update) {
227 pwm = final_pwm;
228 state->duty_cycle = DIV_ROUND_UP(pwm * (period - 1), MAX_PWM);
229 usleep_range(ctx->pwm_usec_from_stopped,
230 ctx->pwm_usec_from_stopped * 2);
231 ret = pwm_apply_might_sleep(ctx->pwm, state);
232 }
233 } else {
234 ret = pwm_fan_power_off(ctx, false);
235 }
236 if (!ret)
237 ctx->pwm_value = pwm;
238
239 return ret;
240}
241
242static int set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm)
243{
244 int ret;
245
246 mutex_lock(&ctx->lock);
247 ret = __set_pwm(ctx, pwm);
248 mutex_unlock(&ctx->lock);
249
250 return ret;
251}
252
253static void pwm_fan_update_state(struct pwm_fan_ctx *ctx, unsigned long pwm)
254{
255 int i;
256
257 for (i = 0; i < ctx->pwm_fan_max_state; ++i)
258 if (pwm < ctx->pwm_fan_cooling_levels[i + 1])
259 break;
260
261 ctx->pwm_fan_state = i;
262}
263
264static int pwm_fan_update_enable(struct pwm_fan_ctx *ctx, long val)
265{
266 int ret = 0;
267 int old_val;
268
269 mutex_lock(&ctx->lock);
270
271 if (ctx->enable_mode == val)
272 goto out;
273
274 old_val = ctx->enable_mode;
275 ctx->enable_mode = val;
276
277 if (val == 0) {
278 /* Disable pwm-fan unconditionally */
279 if (ctx->enabled)
280 ret = __set_pwm(ctx, 0);
281 else
282 ret = pwm_fan_switch_power(ctx, false);
283 if (ret)
284 ctx->enable_mode = old_val;
285 pwm_fan_update_state(ctx, 0);
286 } else {
287 /*
288 * Change PWM and/or regulator state if currently disabled
289 * Nothing to do if currently enabled
290 */
291 if (!ctx->enabled) {
292 struct pwm_state *state = &ctx->pwm_state;
293 bool enable_regulator = false;
294
295 state->duty_cycle = 0;
296 pwm_fan_enable_mode_2_state(val,
297 state,
298 &enable_regulator);
299
300 pwm_apply_might_sleep(ctx->pwm, state);
301 pwm_fan_switch_power(ctx, enable_regulator);
302 pwm_fan_update_state(ctx, 0);
303 }
304 }
305out:
306 mutex_unlock(&ctx->lock);
307
308 return ret;
309}
310
311static int pwm_fan_write(struct device *dev, enum hwmon_sensor_types type,
312 u32 attr, int channel, long val)
313{
314 struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
315 int ret;
316
317 switch (attr) {
318 case hwmon_pwm_input:
319 if (val < 0 || val > MAX_PWM)
320 return -EINVAL;
321 ret = set_pwm(ctx, val);
322 if (ret)
323 return ret;
324 pwm_fan_update_state(ctx, val);
325 break;
326 case hwmon_pwm_enable:
327 if (val < 0 || val > 3)
328 ret = -EINVAL;
329 else
330 ret = pwm_fan_update_enable(ctx, val);
331
332 return ret;
333 default:
334 return -EOPNOTSUPP;
335 }
336
337 return 0;
338}
339
340static int pwm_fan_read(struct device *dev, enum hwmon_sensor_types type,
341 u32 attr, int channel, long *val)
342{
343 struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
344
345 switch (type) {
346 case hwmon_pwm:
347 switch (attr) {
348 case hwmon_pwm_input:
349 *val = ctx->pwm_value;
350 return 0;
351 case hwmon_pwm_enable:
352 *val = ctx->enable_mode;
353 return 0;
354 }
355 return -EOPNOTSUPP;
356 case hwmon_fan:
357 *val = ctx->tachs[channel].rpm;
358 return 0;
359
360 default:
361 return -ENOTSUPP;
362 }
363}
364
365static umode_t pwm_fan_is_visible(const void *data,
366 enum hwmon_sensor_types type,
367 u32 attr, int channel)
368{
369 switch (type) {
370 case hwmon_pwm:
371 return 0644;
372
373 case hwmon_fan:
374 return 0444;
375
376 default:
377 return 0;
378 }
379}
380
381static const struct hwmon_ops pwm_fan_hwmon_ops = {
382 .is_visible = pwm_fan_is_visible,
383 .read = pwm_fan_read,
384 .write = pwm_fan_write,
385};
386
387/* thermal cooling device callbacks */
388static int pwm_fan_get_max_state(struct thermal_cooling_device *cdev,
389 unsigned long *state)
390{
391 struct pwm_fan_ctx *ctx = cdev->devdata;
392
393 if (!ctx)
394 return -EINVAL;
395
396 *state = ctx->pwm_fan_max_state;
397
398 return 0;
399}
400
401static int pwm_fan_get_cur_state(struct thermal_cooling_device *cdev,
402 unsigned long *state)
403{
404 struct pwm_fan_ctx *ctx = cdev->devdata;
405
406 if (!ctx)
407 return -EINVAL;
408
409 *state = ctx->pwm_fan_state;
410
411 return 0;
412}
413
414static int
415pwm_fan_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state)
416{
417 struct pwm_fan_ctx *ctx = cdev->devdata;
418 int ret;
419
420 if (!ctx || (state > ctx->pwm_fan_max_state))
421 return -EINVAL;
422
423 if (state == ctx->pwm_fan_state)
424 return 0;
425
426 ret = set_pwm(ctx, ctx->pwm_fan_cooling_levels[state]);
427 if (ret) {
428 dev_err(&cdev->device, "Cannot set pwm!\n");
429 return ret;
430 }
431
432 ctx->pwm_fan_state = state;
433
434 return ret;
435}
436
437static const struct thermal_cooling_device_ops pwm_fan_cooling_ops = {
438 .get_max_state = pwm_fan_get_max_state,
439 .get_cur_state = pwm_fan_get_cur_state,
440 .set_cur_state = pwm_fan_set_cur_state,
441};
442
443static int pwm_fan_get_cooling_data(struct device *dev, struct pwm_fan_ctx *ctx)
444{
445 int num, i, ret;
446
447 if (!device_property_present(dev, "cooling-levels"))
448 return 0;
449
450 ret = device_property_count_u32(dev, "cooling-levels");
451 if (ret <= 0) {
452 dev_err(dev, "Wrong data!\n");
453 return ret ? : -EINVAL;
454 }
455
456 num = ret;
457 ctx->pwm_fan_cooling_levels = devm_kcalloc(dev, num, sizeof(u32),
458 GFP_KERNEL);
459 if (!ctx->pwm_fan_cooling_levels)
460 return -ENOMEM;
461
462 ret = device_property_read_u32_array(dev, "cooling-levels",
463 ctx->pwm_fan_cooling_levels, num);
464 if (ret) {
465 dev_err(dev, "Property 'cooling-levels' cannot be read!\n");
466 return ret;
467 }
468
469 for (i = 0; i < num; i++) {
470 if (ctx->pwm_fan_cooling_levels[i] > MAX_PWM) {
471 dev_err(dev, "PWM fan state[%d]:%d > %d\n", i,
472 ctx->pwm_fan_cooling_levels[i], MAX_PWM);
473 return -EINVAL;
474 }
475 }
476
477 ctx->pwm_fan_max_state = num - 1;
478
479 return 0;
480}
481
482static void pwm_fan_cleanup(void *__ctx)
483{
484 struct pwm_fan_ctx *ctx = __ctx;
485
486 if (ctx->pwm_shutdown) {
487 ctx->enable_mode = pwm_enable_reg_enable;
488 __set_pwm(ctx, ctx->pwm_shutdown);
489 } else {
490 /* Switch off everything */
491 ctx->enable_mode = pwm_disable_reg_disable;
492 pwm_fan_power_off(ctx, true);
493 }
494}
495
496static void pwm_fan_timer_cleanup(void *__ctx)
497{
498 struct pwm_fan_ctx *ctx = __ctx;
499
500 timer_shutdown_sync(&ctx->rpm_timer);
501}
502
503static int pwm_fan_probe(struct platform_device *pdev)
504{
505 struct thermal_cooling_device *cdev;
506 struct device *dev = &pdev->dev;
507 struct pwm_fan_ctx *ctx;
508 struct device *hwmon;
509 int ret;
510 const struct hwmon_channel_info **channels;
511 u32 initial_pwm, pwm_min_from_stopped = 0;
512 u32 pwm_shutdown_percent = 0;
513 u32 *fan_channel_config;
514 int channel_count = 1; /* We always have a PWM channel. */
515 int i;
516
517 ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
518 if (!ctx)
519 return -ENOMEM;
520
521 mutex_init(&ctx->lock);
522
523 ctx->dev = &pdev->dev;
524 ctx->pwm = devm_pwm_get(dev, NULL);
525 if (IS_ERR(ctx->pwm))
526 return dev_err_probe(dev, PTR_ERR(ctx->pwm), "Could not get PWM\n");
527
528 platform_set_drvdata(pdev, ctx);
529
530 ctx->reg_en = devm_regulator_get_optional(dev, "fan");
531 if (IS_ERR(ctx->reg_en)) {
532 if (PTR_ERR(ctx->reg_en) != -ENODEV)
533 return PTR_ERR(ctx->reg_en);
534
535 ctx->reg_en = NULL;
536 }
537
538 pwm_init_state(ctx->pwm, &ctx->pwm_state);
539
540 /*
541 * PWM fans are controlled solely by the duty cycle of the PWM signal,
542 * they do not care about the exact timing. Thus set usage_power to true
543 * to allow less flexible hardware to work as a PWM source for fan
544 * control.
545 */
546 ctx->pwm_state.usage_power = true;
547
548 /*
549 * set_pwm assumes that MAX_PWM * (period - 1) fits into an unsigned
550 * long. Check this here to prevent the fan running at a too low
551 * frequency.
552 */
553 if (ctx->pwm_state.period > ULONG_MAX / MAX_PWM + 1) {
554 dev_err(dev, "Configured period too big\n");
555 return -EINVAL;
556 }
557
558 ctx->enable_mode = pwm_disable_reg_enable;
559
560 ret = pwm_fan_get_cooling_data(dev, ctx);
561 if (ret)
562 return ret;
563
564 /* use maximum cooling level if provided */
565 if (ctx->pwm_fan_cooling_levels)
566 initial_pwm = ctx->pwm_fan_cooling_levels[ctx->pwm_fan_max_state];
567 else
568 initial_pwm = MAX_PWM;
569
570 /*
571 * Set duty cycle to maximum allowed and enable PWM output as well as
572 * the regulator. In case of error nothing is changed
573 */
574 ret = set_pwm(ctx, initial_pwm);
575 if (ret) {
576 dev_err(dev, "Failed to configure PWM: %d\n", ret);
577 return ret;
578 }
579 timer_setup(&ctx->rpm_timer, sample_timer, 0);
580 ret = devm_add_action_or_reset(dev, pwm_fan_cleanup, ctx);
581 if (ret)
582 return ret;
583
584 ctx->tach_count = platform_irq_count(pdev);
585 if (ctx->tach_count < 0)
586 return dev_err_probe(dev, ctx->tach_count,
587 "Could not get number of fan tachometer inputs\n");
588 dev_dbg(dev, "%d fan tachometer inputs\n", ctx->tach_count);
589
590 if (ctx->tach_count) {
591 channel_count++; /* We also have a FAN channel. */
592
593 ctx->tachs = devm_kcalloc(dev, ctx->tach_count,
594 sizeof(struct pwm_fan_tach),
595 GFP_KERNEL);
596 if (!ctx->tachs)
597 return -ENOMEM;
598
599 ctx->fan_channel.type = hwmon_fan;
600 fan_channel_config = devm_kcalloc(dev, ctx->tach_count + 1,
601 sizeof(u32), GFP_KERNEL);
602 if (!fan_channel_config)
603 return -ENOMEM;
604 ctx->fan_channel.config = fan_channel_config;
605
606 ctx->pulses_per_revolution = devm_kmalloc_array(dev,
607 ctx->tach_count,
608 sizeof(*ctx->pulses_per_revolution),
609 GFP_KERNEL);
610 if (!ctx->pulses_per_revolution)
611 return -ENOMEM;
612
613 /* Setup default pulses per revolution */
614 for (i = 0; i < ctx->tach_count; i++)
615 ctx->pulses_per_revolution[i] = 2;
616
617 device_property_read_u32_array(dev, "pulses-per-revolution",
618 ctx->pulses_per_revolution, ctx->tach_count);
619 }
620
621 channels = devm_kcalloc(dev, channel_count + 1,
622 sizeof(struct hwmon_channel_info *), GFP_KERNEL);
623 if (!channels)
624 return -ENOMEM;
625
626 channels[0] = HWMON_CHANNEL_INFO(pwm, HWMON_PWM_INPUT | HWMON_PWM_ENABLE);
627
628 for (i = 0; i < ctx->tach_count; i++) {
629 struct pwm_fan_tach *tach = &ctx->tachs[i];
630
631 tach->irq = platform_get_irq(pdev, i);
632 if (tach->irq == -EPROBE_DEFER)
633 return tach->irq;
634 if (tach->irq > 0) {
635 ret = devm_request_irq(dev, tach->irq, pulse_handler,
636 IRQF_NO_THREAD, pdev->name, tach);
637 if (ret)
638 return ret;
639 }
640
641 if (!ctx->pulses_per_revolution[i]) {
642 dev_err(dev, "pulses-per-revolution can't be zero.\n");
643 return -EINVAL;
644 }
645
646 fan_channel_config[i] = HWMON_F_INPUT;
647
648 dev_dbg(dev, "tach%d: irq=%d, pulses_per_revolution=%d\n",
649 i, tach->irq, ctx->pulses_per_revolution[i]);
650 }
651
652 if (ctx->tach_count > 0) {
653 ret = devm_add_action_or_reset(dev, pwm_fan_timer_cleanup, ctx);
654 if (ret)
655 return ret;
656
657 ctx->sample_start = ktime_get();
658 mod_timer(&ctx->rpm_timer, jiffies + HZ);
659
660 channels[1] = &ctx->fan_channel;
661 }
662
663 ret = device_property_read_u32(dev, "fan-shutdown-percent",
664 &pwm_shutdown_percent);
665 if (!ret && pwm_shutdown_percent)
666 ctx->pwm_shutdown = (clamp(pwm_shutdown_percent, 0, 100) * 255) / 100;
667
668 ret = device_property_read_u32(dev, "fan-stop-to-start-percent",
669 &pwm_min_from_stopped);
670 if (!ret && pwm_min_from_stopped) {
671 ctx->pwm_duty_cycle_from_stopped =
672 DIV_ROUND_UP_ULL(pwm_min_from_stopped *
673 (ctx->pwm_state.period - 1),
674 100);
675 }
676 ret = device_property_read_u32(dev, "fan-stop-to-start-us",
677 &ctx->pwm_usec_from_stopped);
678 if (ret)
679 ctx->pwm_usec_from_stopped = 250000;
680
681 ctx->info.ops = &pwm_fan_hwmon_ops;
682 ctx->info.info = channels;
683
684 hwmon = devm_hwmon_device_register_with_info(dev, "pwmfan",
685 ctx, &ctx->info, NULL);
686 if (IS_ERR(hwmon)) {
687 dev_err(dev, "Failed to register hwmon device\n");
688 return PTR_ERR(hwmon);
689 }
690
691 ctx->pwm_fan_state = ctx->pwm_fan_max_state;
692 if (IS_ENABLED(CONFIG_THERMAL)) {
693 cdev = devm_thermal_of_child_cooling_device_register(dev, dev->of_node,
694 "pwm-fan", ctx,
695 &pwm_fan_cooling_ops);
696 if (IS_ERR(cdev)) {
697 ret = PTR_ERR(cdev);
698 dev_err(dev,
699 "Failed to register pwm-fan as cooling device: %d\n",
700 ret);
701 return ret;
702 }
703 ctx->cdev = cdev;
704 }
705
706 return 0;
707}
708
709static void pwm_fan_shutdown(struct platform_device *pdev)
710{
711 struct pwm_fan_ctx *ctx = platform_get_drvdata(pdev);
712
713 pwm_fan_timer_cleanup(ctx);
714 pwm_fan_cleanup(ctx);
715}
716
717static int pwm_fan_suspend(struct device *dev)
718{
719 struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
720
721 return pwm_fan_power_off(ctx, true);
722}
723
724static int pwm_fan_resume(struct device *dev)
725{
726 struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
727
728 return set_pwm(ctx, ctx->pwm_value);
729}
730
731static DEFINE_SIMPLE_DEV_PM_OPS(pwm_fan_pm, pwm_fan_suspend, pwm_fan_resume);
732
733static const struct of_device_id of_pwm_fan_match[] = {
734 { .compatible = "pwm-fan", },
735 {},
736};
737MODULE_DEVICE_TABLE(of, of_pwm_fan_match);
738
739static struct platform_driver pwm_fan_driver = {
740 .probe = pwm_fan_probe,
741 .shutdown = pwm_fan_shutdown,
742 .driver = {
743 .name = "pwm-fan",
744 .pm = pm_sleep_ptr(&pwm_fan_pm),
745 .of_match_table = of_pwm_fan_match,
746 },
747};
748
749module_platform_driver(pwm_fan_driver);
750
751MODULE_AUTHOR("Kamil Debski <[email protected]>");
752MODULE_ALIAS("platform:pwm-fan");
753MODULE_DESCRIPTION("PWM FAN driver");
754MODULE_LICENSE("GPL");