drm:verisilicon:hdmi-audio:Adjust when to configure registers
[platform/kernel/linux-starfive.git] / drivers / pwm / pwm-atmel-tcb.c
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) Overkiz SAS 2012
4  *
5  * Author: Boris BREZILLON <b.brezillon@overkiz.com>
6  */
7
8 #include <linux/module.h>
9 #include <linux/init.h>
10 #include <linux/clocksource.h>
11 #include <linux/clockchips.h>
12 #include <linux/interrupt.h>
13 #include <linux/irq.h>
14
15 #include <linux/clk.h>
16 #include <linux/err.h>
17 #include <linux/ioport.h>
18 #include <linux/io.h>
19 #include <linux/mfd/syscon.h>
20 #include <linux/platform_device.h>
21 #include <linux/pwm.h>
22 #include <linux/of_device.h>
23 #include <linux/of_irq.h>
24 #include <linux/regmap.h>
25 #include <linux/slab.h>
26 #include <soc/at91/atmel_tcb.h>
27
28 #define NPWM    2
29
30 #define ATMEL_TC_ACMR_MASK      (ATMEL_TC_ACPA | ATMEL_TC_ACPC |        \
31                                  ATMEL_TC_AEEVT | ATMEL_TC_ASWTRG)
32
33 #define ATMEL_TC_BCMR_MASK      (ATMEL_TC_BCPB | ATMEL_TC_BCPC |        \
34                                  ATMEL_TC_BEEVT | ATMEL_TC_BSWTRG)
35
36 struct atmel_tcb_pwm_device {
37         enum pwm_polarity polarity;     /* PWM polarity */
38         unsigned div;                   /* PWM clock divider */
39         unsigned duty;                  /* PWM duty expressed in clk cycles */
40         unsigned period;                /* PWM period expressed in clk cycles */
41 };
42
43 struct atmel_tcb_channel {
44         u32 enabled;
45         u32 cmr;
46         u32 ra;
47         u32 rb;
48         u32 rc;
49 };
50
51 struct atmel_tcb_pwm_chip {
52         struct pwm_chip chip;
53         spinlock_t lock;
54         u8 channel;
55         u8 width;
56         struct regmap *regmap;
57         struct clk *clk;
58         struct clk *gclk;
59         struct clk *slow_clk;
60         struct atmel_tcb_pwm_device *pwms[NPWM];
61         struct atmel_tcb_channel bkup;
62 };
63
64 const u8 atmel_tcb_divisors[] = { 2, 8, 32, 128, 0, };
65
66 static inline struct atmel_tcb_pwm_chip *to_tcb_chip(struct pwm_chip *chip)
67 {
68         return container_of(chip, struct atmel_tcb_pwm_chip, chip);
69 }
70
71 static int atmel_tcb_pwm_set_polarity(struct pwm_chip *chip,
72                                       struct pwm_device *pwm,
73                                       enum pwm_polarity polarity)
74 {
75         struct atmel_tcb_pwm_device *tcbpwm = pwm_get_chip_data(pwm);
76
77         tcbpwm->polarity = polarity;
78
79         return 0;
80 }
81
82 static int atmel_tcb_pwm_request(struct pwm_chip *chip,
83                                  struct pwm_device *pwm)
84 {
85         struct atmel_tcb_pwm_chip *tcbpwmc = to_tcb_chip(chip);
86         struct atmel_tcb_pwm_device *tcbpwm;
87         unsigned cmr;
88         int ret;
89
90         tcbpwm = devm_kzalloc(chip->dev, sizeof(*tcbpwm), GFP_KERNEL);
91         if (!tcbpwm)
92                 return -ENOMEM;
93
94         ret = clk_prepare_enable(tcbpwmc->clk);
95         if (ret) {
96                 devm_kfree(chip->dev, tcbpwm);
97                 return ret;
98         }
99
100         pwm_set_chip_data(pwm, tcbpwm);
101         tcbpwm->polarity = PWM_POLARITY_NORMAL;
102         tcbpwm->duty = 0;
103         tcbpwm->period = 0;
104         tcbpwm->div = 0;
105
106         spin_lock(&tcbpwmc->lock);
107         regmap_read(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, CMR), &cmr);
108         /*
109          * Get init config from Timer Counter registers if
110          * Timer Counter is already configured as a PWM generator.
111          */
112         if (cmr & ATMEL_TC_WAVE) {
113                 if (pwm->hwpwm == 0)
114                         regmap_read(tcbpwmc->regmap,
115                                     ATMEL_TC_REG(tcbpwmc->channel, RA),
116                                     &tcbpwm->duty);
117                 else
118                         regmap_read(tcbpwmc->regmap,
119                                     ATMEL_TC_REG(tcbpwmc->channel, RB),
120                                     &tcbpwm->duty);
121
122                 tcbpwm->div = cmr & ATMEL_TC_TCCLKS;
123                 regmap_read(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, RC),
124                             &tcbpwm->period);
125                 cmr &= (ATMEL_TC_TCCLKS | ATMEL_TC_ACMR_MASK |
126                         ATMEL_TC_BCMR_MASK);
127         } else
128                 cmr = 0;
129
130         cmr |= ATMEL_TC_WAVE | ATMEL_TC_WAVESEL_UP_AUTO | ATMEL_TC_EEVT_XC0;
131         regmap_write(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, CMR), cmr);
132         spin_unlock(&tcbpwmc->lock);
133
134         tcbpwmc->pwms[pwm->hwpwm] = tcbpwm;
135
136         return 0;
137 }
138
139 static void atmel_tcb_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
140 {
141         struct atmel_tcb_pwm_chip *tcbpwmc = to_tcb_chip(chip);
142         struct atmel_tcb_pwm_device *tcbpwm = pwm_get_chip_data(pwm);
143
144         clk_disable_unprepare(tcbpwmc->clk);
145         tcbpwmc->pwms[pwm->hwpwm] = NULL;
146         devm_kfree(chip->dev, tcbpwm);
147 }
148
149 static void atmel_tcb_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
150 {
151         struct atmel_tcb_pwm_chip *tcbpwmc = to_tcb_chip(chip);
152         struct atmel_tcb_pwm_device *tcbpwm = pwm_get_chip_data(pwm);
153         unsigned cmr;
154         enum pwm_polarity polarity = tcbpwm->polarity;
155
156         /*
157          * If duty is 0 the timer will be stopped and we have to
158          * configure the output correctly on software trigger:
159          *  - set output to high if PWM_POLARITY_INVERSED
160          *  - set output to low if PWM_POLARITY_NORMAL
161          *
162          * This is why we're reverting polarity in this case.
163          */
164         if (tcbpwm->duty == 0)
165                 polarity = !polarity;
166
167         spin_lock(&tcbpwmc->lock);
168         regmap_read(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, CMR), &cmr);
169
170         /* flush old setting and set the new one */
171         if (pwm->hwpwm == 0) {
172                 cmr &= ~ATMEL_TC_ACMR_MASK;
173                 if (polarity == PWM_POLARITY_INVERSED)
174                         cmr |= ATMEL_TC_ASWTRG_CLEAR;
175                 else
176                         cmr |= ATMEL_TC_ASWTRG_SET;
177         } else {
178                 cmr &= ~ATMEL_TC_BCMR_MASK;
179                 if (polarity == PWM_POLARITY_INVERSED)
180                         cmr |= ATMEL_TC_BSWTRG_CLEAR;
181                 else
182                         cmr |= ATMEL_TC_BSWTRG_SET;
183         }
184
185         regmap_write(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, CMR), cmr);
186
187         /*
188          * Use software trigger to apply the new setting.
189          * If both PWM devices in this group are disabled we stop the clock.
190          */
191         if (!(cmr & (ATMEL_TC_ACPC | ATMEL_TC_BCPC))) {
192                 regmap_write(tcbpwmc->regmap,
193                              ATMEL_TC_REG(tcbpwmc->channel, CCR),
194                              ATMEL_TC_SWTRG | ATMEL_TC_CLKDIS);
195                 tcbpwmc->bkup.enabled = 1;
196         } else {
197                 regmap_write(tcbpwmc->regmap,
198                              ATMEL_TC_REG(tcbpwmc->channel, CCR),
199                              ATMEL_TC_SWTRG);
200                 tcbpwmc->bkup.enabled = 0;
201         }
202
203         spin_unlock(&tcbpwmc->lock);
204 }
205
206 static int atmel_tcb_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
207 {
208         struct atmel_tcb_pwm_chip *tcbpwmc = to_tcb_chip(chip);
209         struct atmel_tcb_pwm_device *tcbpwm = pwm_get_chip_data(pwm);
210         u32 cmr;
211         enum pwm_polarity polarity = tcbpwm->polarity;
212
213         /*
214          * If duty is 0 the timer will be stopped and we have to
215          * configure the output correctly on software trigger:
216          *  - set output to high if PWM_POLARITY_INVERSED
217          *  - set output to low if PWM_POLARITY_NORMAL
218          *
219          * This is why we're reverting polarity in this case.
220          */
221         if (tcbpwm->duty == 0)
222                 polarity = !polarity;
223
224         spin_lock(&tcbpwmc->lock);
225         regmap_read(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, CMR), &cmr);
226
227         /* flush old setting and set the new one */
228         cmr &= ~ATMEL_TC_TCCLKS;
229
230         if (pwm->hwpwm == 0) {
231                 cmr &= ~ATMEL_TC_ACMR_MASK;
232
233                 /* Set CMR flags according to given polarity */
234                 if (polarity == PWM_POLARITY_INVERSED)
235                         cmr |= ATMEL_TC_ASWTRG_CLEAR;
236                 else
237                         cmr |= ATMEL_TC_ASWTRG_SET;
238         } else {
239                 cmr &= ~ATMEL_TC_BCMR_MASK;
240                 if (polarity == PWM_POLARITY_INVERSED)
241                         cmr |= ATMEL_TC_BSWTRG_CLEAR;
242                 else
243                         cmr |= ATMEL_TC_BSWTRG_SET;
244         }
245
246         /*
247          * If duty is 0 or equal to period there's no need to register
248          * a specific action on RA/RB and RC compare.
249          * The output will be configured on software trigger and keep
250          * this config till next config call.
251          */
252         if (tcbpwm->duty != tcbpwm->period && tcbpwm->duty > 0) {
253                 if (pwm->hwpwm == 0) {
254                         if (polarity == PWM_POLARITY_INVERSED)
255                                 cmr |= ATMEL_TC_ACPA_SET | ATMEL_TC_ACPC_CLEAR;
256                         else
257                                 cmr |= ATMEL_TC_ACPA_CLEAR | ATMEL_TC_ACPC_SET;
258                 } else {
259                         if (polarity == PWM_POLARITY_INVERSED)
260                                 cmr |= ATMEL_TC_BCPB_SET | ATMEL_TC_BCPC_CLEAR;
261                         else
262                                 cmr |= ATMEL_TC_BCPB_CLEAR | ATMEL_TC_BCPC_SET;
263                 }
264         }
265
266         cmr |= (tcbpwm->div & ATMEL_TC_TCCLKS);
267
268         regmap_write(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, CMR), cmr);
269
270         if (pwm->hwpwm == 0)
271                 regmap_write(tcbpwmc->regmap,
272                              ATMEL_TC_REG(tcbpwmc->channel, RA),
273                              tcbpwm->duty);
274         else
275                 regmap_write(tcbpwmc->regmap,
276                              ATMEL_TC_REG(tcbpwmc->channel, RB),
277                              tcbpwm->duty);
278
279         regmap_write(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, RC),
280                      tcbpwm->period);
281
282         /* Use software trigger to apply the new setting */
283         regmap_write(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, CCR),
284                      ATMEL_TC_SWTRG | ATMEL_TC_CLKEN);
285         tcbpwmc->bkup.enabled = 1;
286         spin_unlock(&tcbpwmc->lock);
287         return 0;
288 }
289
290 static int atmel_tcb_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
291                                 int duty_ns, int period_ns)
292 {
293         struct atmel_tcb_pwm_chip *tcbpwmc = to_tcb_chip(chip);
294         struct atmel_tcb_pwm_device *tcbpwm = pwm_get_chip_data(pwm);
295         struct atmel_tcb_pwm_device *atcbpwm = NULL;
296         int i = 0;
297         int slowclk = 0;
298         unsigned period;
299         unsigned duty;
300         unsigned rate = clk_get_rate(tcbpwmc->clk);
301         unsigned long long min;
302         unsigned long long max;
303
304         /*
305          * Find best clk divisor:
306          * the smallest divisor which can fulfill the period_ns requirements.
307          * If there is a gclk, the first divisor is actuallly the gclk selector
308          */
309         if (tcbpwmc->gclk)
310                 i = 1;
311         for (; i < ARRAY_SIZE(atmel_tcb_divisors); ++i) {
312                 if (atmel_tcb_divisors[i] == 0) {
313                         slowclk = i;
314                         continue;
315                 }
316                 min = div_u64((u64)NSEC_PER_SEC * atmel_tcb_divisors[i], rate);
317                 max = min << tcbpwmc->width;
318                 if (max >= period_ns)
319                         break;
320         }
321
322         /*
323          * If none of the divisor are small enough to represent period_ns
324          * take slow clock (32KHz).
325          */
326         if (i == ARRAY_SIZE(atmel_tcb_divisors)) {
327                 i = slowclk;
328                 rate = clk_get_rate(tcbpwmc->slow_clk);
329                 min = div_u64(NSEC_PER_SEC, rate);
330                 max = min << tcbpwmc->width;
331
332                 /* If period is too big return ERANGE error */
333                 if (max < period_ns)
334                         return -ERANGE;
335         }
336
337         duty = div_u64(duty_ns, min);
338         period = div_u64(period_ns, min);
339
340         if (pwm->hwpwm == 0)
341                 atcbpwm = tcbpwmc->pwms[1];
342         else
343                 atcbpwm = tcbpwmc->pwms[0];
344
345         /*
346          * PWM devices provided by the TCB driver are grouped by 2.
347          * PWM devices in a given group must be configured with the
348          * same period_ns.
349          *
350          * We're checking the period value of the second PWM device
351          * in this group before applying the new config.
352          */
353         if ((atcbpwm && atcbpwm->duty > 0 &&
354                         atcbpwm->duty != atcbpwm->period) &&
355                 (atcbpwm->div != i || atcbpwm->period != period)) {
356                 dev_err(chip->dev,
357                         "failed to configure period_ns: PWM group already configured with a different value\n");
358                 return -EINVAL;
359         }
360
361         tcbpwm->period = period;
362         tcbpwm->div = i;
363         tcbpwm->duty = duty;
364
365         return 0;
366 }
367
368 static int atmel_tcb_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
369                                const struct pwm_state *state)
370 {
371         int duty_cycle, period;
372         int ret;
373
374         /* This function only sets a flag in driver data */
375         atmel_tcb_pwm_set_polarity(chip, pwm, state->polarity);
376
377         if (!state->enabled) {
378                 atmel_tcb_pwm_disable(chip, pwm);
379                 return 0;
380         }
381
382         period = state->period < INT_MAX ? state->period : INT_MAX;
383         duty_cycle = state->duty_cycle < INT_MAX ? state->duty_cycle : INT_MAX;
384
385         ret = atmel_tcb_pwm_config(chip, pwm, duty_cycle, period);
386         if (ret)
387                 return ret;
388
389         return atmel_tcb_pwm_enable(chip, pwm);
390 }
391
392 static const struct pwm_ops atmel_tcb_pwm_ops = {
393         .request = atmel_tcb_pwm_request,
394         .free = atmel_tcb_pwm_free,
395         .apply = atmel_tcb_pwm_apply,
396         .owner = THIS_MODULE,
397 };
398
399 static struct atmel_tcb_config tcb_rm9200_config = {
400         .counter_width = 16,
401 };
402
403 static struct atmel_tcb_config tcb_sam9x5_config = {
404         .counter_width = 32,
405 };
406
407 static struct atmel_tcb_config tcb_sama5d2_config = {
408         .counter_width = 32,
409         .has_gclk = 1,
410 };
411
412 static const struct of_device_id atmel_tcb_of_match[] = {
413         { .compatible = "atmel,at91rm9200-tcb", .data = &tcb_rm9200_config, },
414         { .compatible = "atmel,at91sam9x5-tcb", .data = &tcb_sam9x5_config, },
415         { .compatible = "atmel,sama5d2-tcb", .data = &tcb_sama5d2_config, },
416         { /* sentinel */ }
417 };
418
419 static int atmel_tcb_pwm_probe(struct platform_device *pdev)
420 {
421         const struct of_device_id *match;
422         struct atmel_tcb_pwm_chip *tcbpwm;
423         const struct atmel_tcb_config *config;
424         struct device_node *np = pdev->dev.of_node;
425         struct regmap *regmap;
426         struct clk *clk, *gclk = NULL;
427         struct clk *slow_clk;
428         char clk_name[] = "t0_clk";
429         int err;
430         int channel;
431
432         err = of_property_read_u32(np, "reg", &channel);
433         if (err < 0) {
434                 dev_err(&pdev->dev,
435                         "failed to get Timer Counter Block channel from device tree (error: %d)\n",
436                         err);
437                 return err;
438         }
439
440         regmap = syscon_node_to_regmap(np->parent);
441         if (IS_ERR(regmap))
442                 return PTR_ERR(regmap);
443
444         slow_clk = of_clk_get_by_name(np->parent, "slow_clk");
445         if (IS_ERR(slow_clk))
446                 return PTR_ERR(slow_clk);
447
448         clk_name[1] += channel;
449         clk = of_clk_get_by_name(np->parent, clk_name);
450         if (IS_ERR(clk))
451                 clk = of_clk_get_by_name(np->parent, "t0_clk");
452         if (IS_ERR(clk))
453                 return PTR_ERR(clk);
454
455         match = of_match_node(atmel_tcb_of_match, np->parent);
456         config = match->data;
457
458         if (config->has_gclk) {
459                 gclk = of_clk_get_by_name(np->parent, "gclk");
460                 if (IS_ERR(gclk))
461                         return PTR_ERR(gclk);
462         }
463
464         tcbpwm = devm_kzalloc(&pdev->dev, sizeof(*tcbpwm), GFP_KERNEL);
465         if (tcbpwm == NULL) {
466                 err = -ENOMEM;
467                 goto err_slow_clk;
468         }
469
470         tcbpwm->chip.dev = &pdev->dev;
471         tcbpwm->chip.ops = &atmel_tcb_pwm_ops;
472         tcbpwm->chip.npwm = NPWM;
473         tcbpwm->channel = channel;
474         tcbpwm->regmap = regmap;
475         tcbpwm->clk = clk;
476         tcbpwm->gclk = gclk;
477         tcbpwm->slow_clk = slow_clk;
478         tcbpwm->width = config->counter_width;
479
480         err = clk_prepare_enable(slow_clk);
481         if (err)
482                 goto err_slow_clk;
483
484         spin_lock_init(&tcbpwm->lock);
485
486         err = pwmchip_add(&tcbpwm->chip);
487         if (err < 0)
488                 goto err_disable_clk;
489
490         platform_set_drvdata(pdev, tcbpwm);
491
492         return 0;
493
494 err_disable_clk:
495         clk_disable_unprepare(tcbpwm->slow_clk);
496
497 err_slow_clk:
498         clk_put(slow_clk);
499
500         return err;
501 }
502
503 static int atmel_tcb_pwm_remove(struct platform_device *pdev)
504 {
505         struct atmel_tcb_pwm_chip *tcbpwm = platform_get_drvdata(pdev);
506
507         pwmchip_remove(&tcbpwm->chip);
508
509         clk_disable_unprepare(tcbpwm->slow_clk);
510         clk_put(tcbpwm->slow_clk);
511         clk_put(tcbpwm->clk);
512
513         return 0;
514 }
515
516 static const struct of_device_id atmel_tcb_pwm_dt_ids[] = {
517         { .compatible = "atmel,tcb-pwm", },
518         { /* sentinel */ }
519 };
520 MODULE_DEVICE_TABLE(of, atmel_tcb_pwm_dt_ids);
521
522 #ifdef CONFIG_PM_SLEEP
523 static int atmel_tcb_pwm_suspend(struct device *dev)
524 {
525         struct atmel_tcb_pwm_chip *tcbpwm = dev_get_drvdata(dev);
526         struct atmel_tcb_channel *chan = &tcbpwm->bkup;
527         unsigned int channel = tcbpwm->channel;
528
529         regmap_read(tcbpwm->regmap, ATMEL_TC_REG(channel, CMR), &chan->cmr);
530         regmap_read(tcbpwm->regmap, ATMEL_TC_REG(channel, RA), &chan->ra);
531         regmap_read(tcbpwm->regmap, ATMEL_TC_REG(channel, RB), &chan->rb);
532         regmap_read(tcbpwm->regmap, ATMEL_TC_REG(channel, RC), &chan->rc);
533
534         return 0;
535 }
536
537 static int atmel_tcb_pwm_resume(struct device *dev)
538 {
539         struct atmel_tcb_pwm_chip *tcbpwm = dev_get_drvdata(dev);
540         struct atmel_tcb_channel *chan = &tcbpwm->bkup;
541         unsigned int channel = tcbpwm->channel;
542
543         regmap_write(tcbpwm->regmap, ATMEL_TC_REG(channel, CMR), chan->cmr);
544         regmap_write(tcbpwm->regmap, ATMEL_TC_REG(channel, RA), chan->ra);
545         regmap_write(tcbpwm->regmap, ATMEL_TC_REG(channel, RB), chan->rb);
546         regmap_write(tcbpwm->regmap, ATMEL_TC_REG(channel, RC), chan->rc);
547
548         if (chan->enabled)
549                 regmap_write(tcbpwm->regmap,
550                              ATMEL_TC_CLKEN | ATMEL_TC_SWTRG,
551                              ATMEL_TC_REG(channel, CCR));
552
553         return 0;
554 }
555 #endif
556
557 static SIMPLE_DEV_PM_OPS(atmel_tcb_pwm_pm_ops, atmel_tcb_pwm_suspend,
558                          atmel_tcb_pwm_resume);
559
560 static struct platform_driver atmel_tcb_pwm_driver = {
561         .driver = {
562                 .name = "atmel-tcb-pwm",
563                 .of_match_table = atmel_tcb_pwm_dt_ids,
564                 .pm = &atmel_tcb_pwm_pm_ops,
565         },
566         .probe = atmel_tcb_pwm_probe,
567         .remove = atmel_tcb_pwm_remove,
568 };
569 module_platform_driver(atmel_tcb_pwm_driver);
570
571 MODULE_AUTHOR("Boris BREZILLON <b.brezillon@overkiz.com>");
572 MODULE_DESCRIPTION("Atmel Timer Counter Pulse Width Modulation Driver");
573 MODULE_LICENSE("GPL v2");