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