1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (C) Overkiz SAS 2012
5 * Author: Boris BREZILLON <b.brezillon@overkiz.com>
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>
15 #include <linux/clk.h>
16 #include <linux/err.h>
17 #include <linux/ioport.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>
30 #define ATMEL_TC_ACMR_MASK (ATMEL_TC_ACPA | ATMEL_TC_ACPC | \
31 ATMEL_TC_AEEVT | ATMEL_TC_ASWTRG)
33 #define ATMEL_TC_BCMR_MASK (ATMEL_TC_BCPB | ATMEL_TC_BCPC | \
34 ATMEL_TC_BEEVT | ATMEL_TC_BSWTRG)
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 */
43 struct atmel_tcb_channel {
51 struct atmel_tcb_pwm_chip {
56 struct regmap *regmap;
60 struct atmel_tcb_pwm_device *pwms[NPWM];
61 struct atmel_tcb_channel bkup;
64 const u8 atmel_tcb_divisors[] = { 2, 8, 32, 128, 0, };
66 static inline struct atmel_tcb_pwm_chip *to_tcb_chip(struct pwm_chip *chip)
68 return container_of(chip, struct atmel_tcb_pwm_chip, chip);
71 static int atmel_tcb_pwm_set_polarity(struct pwm_chip *chip,
72 struct pwm_device *pwm,
73 enum pwm_polarity polarity)
75 struct atmel_tcb_pwm_device *tcbpwm = pwm_get_chip_data(pwm);
77 tcbpwm->polarity = polarity;
82 static int atmel_tcb_pwm_request(struct pwm_chip *chip,
83 struct pwm_device *pwm)
85 struct atmel_tcb_pwm_chip *tcbpwmc = to_tcb_chip(chip);
86 struct atmel_tcb_pwm_device *tcbpwm;
90 tcbpwm = devm_kzalloc(chip->dev, sizeof(*tcbpwm), GFP_KERNEL);
94 ret = clk_prepare_enable(tcbpwmc->clk);
96 devm_kfree(chip->dev, tcbpwm);
100 pwm_set_chip_data(pwm, tcbpwm);
101 tcbpwm->polarity = PWM_POLARITY_NORMAL;
106 spin_lock(&tcbpwmc->lock);
107 regmap_read(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, CMR), &cmr);
109 * Get init config from Timer Counter registers if
110 * Timer Counter is already configured as a PWM generator.
112 if (cmr & ATMEL_TC_WAVE) {
114 regmap_read(tcbpwmc->regmap,
115 ATMEL_TC_REG(tcbpwmc->channel, RA),
118 regmap_read(tcbpwmc->regmap,
119 ATMEL_TC_REG(tcbpwmc->channel, RB),
122 tcbpwm->div = cmr & ATMEL_TC_TCCLKS;
123 regmap_read(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, RC),
125 cmr &= (ATMEL_TC_TCCLKS | ATMEL_TC_ACMR_MASK |
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);
134 tcbpwmc->pwms[pwm->hwpwm] = tcbpwm;
139 static void atmel_tcb_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
141 struct atmel_tcb_pwm_chip *tcbpwmc = to_tcb_chip(chip);
142 struct atmel_tcb_pwm_device *tcbpwm = pwm_get_chip_data(pwm);
144 clk_disable_unprepare(tcbpwmc->clk);
145 tcbpwmc->pwms[pwm->hwpwm] = NULL;
146 devm_kfree(chip->dev, tcbpwm);
149 static void atmel_tcb_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
151 struct atmel_tcb_pwm_chip *tcbpwmc = to_tcb_chip(chip);
152 struct atmel_tcb_pwm_device *tcbpwm = pwm_get_chip_data(pwm);
154 enum pwm_polarity polarity = tcbpwm->polarity;
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
162 * This is why we're reverting polarity in this case.
164 if (tcbpwm->duty == 0)
165 polarity = !polarity;
167 spin_lock(&tcbpwmc->lock);
168 regmap_read(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, CMR), &cmr);
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;
176 cmr |= ATMEL_TC_ASWTRG_SET;
178 cmr &= ~ATMEL_TC_BCMR_MASK;
179 if (polarity == PWM_POLARITY_INVERSED)
180 cmr |= ATMEL_TC_BSWTRG_CLEAR;
182 cmr |= ATMEL_TC_BSWTRG_SET;
185 regmap_write(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, CMR), cmr);
188 * Use software trigger to apply the new setting.
189 * If both PWM devices in this group are disabled we stop the clock.
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;
197 regmap_write(tcbpwmc->regmap,
198 ATMEL_TC_REG(tcbpwmc->channel, CCR),
200 tcbpwmc->bkup.enabled = 0;
203 spin_unlock(&tcbpwmc->lock);
206 static int atmel_tcb_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
208 struct atmel_tcb_pwm_chip *tcbpwmc = to_tcb_chip(chip);
209 struct atmel_tcb_pwm_device *tcbpwm = pwm_get_chip_data(pwm);
211 enum pwm_polarity polarity = tcbpwm->polarity;
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
219 * This is why we're reverting polarity in this case.
221 if (tcbpwm->duty == 0)
222 polarity = !polarity;
224 spin_lock(&tcbpwmc->lock);
225 regmap_read(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, CMR), &cmr);
227 /* flush old setting and set the new one */
228 cmr &= ~ATMEL_TC_TCCLKS;
230 if (pwm->hwpwm == 0) {
231 cmr &= ~ATMEL_TC_ACMR_MASK;
233 /* Set CMR flags according to given polarity */
234 if (polarity == PWM_POLARITY_INVERSED)
235 cmr |= ATMEL_TC_ASWTRG_CLEAR;
237 cmr |= ATMEL_TC_ASWTRG_SET;
239 cmr &= ~ATMEL_TC_BCMR_MASK;
240 if (polarity == PWM_POLARITY_INVERSED)
241 cmr |= ATMEL_TC_BSWTRG_CLEAR;
243 cmr |= ATMEL_TC_BSWTRG_SET;
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.
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;
257 cmr |= ATMEL_TC_ACPA_CLEAR | ATMEL_TC_ACPC_SET;
259 if (polarity == PWM_POLARITY_INVERSED)
260 cmr |= ATMEL_TC_BCPB_SET | ATMEL_TC_BCPC_CLEAR;
262 cmr |= ATMEL_TC_BCPB_CLEAR | ATMEL_TC_BCPC_SET;
266 cmr |= (tcbpwm->div & ATMEL_TC_TCCLKS);
268 regmap_write(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, CMR), cmr);
271 regmap_write(tcbpwmc->regmap,
272 ATMEL_TC_REG(tcbpwmc->channel, RA),
275 regmap_write(tcbpwmc->regmap,
276 ATMEL_TC_REG(tcbpwmc->channel, RB),
279 regmap_write(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, RC),
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);
290 static int atmel_tcb_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
291 int duty_ns, int period_ns)
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;
300 unsigned rate = clk_get_rate(tcbpwmc->clk);
301 unsigned long long min;
302 unsigned long long max;
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
311 for (; i < ARRAY_SIZE(atmel_tcb_divisors); ++i) {
312 if (atmel_tcb_divisors[i] == 0) {
316 min = div_u64((u64)NSEC_PER_SEC * atmel_tcb_divisors[i], rate);
317 max = min << tcbpwmc->width;
318 if (max >= period_ns)
323 * If none of the divisor are small enough to represent period_ns
324 * take slow clock (32KHz).
326 if (i == ARRAY_SIZE(atmel_tcb_divisors)) {
328 rate = clk_get_rate(tcbpwmc->slow_clk);
329 min = div_u64(NSEC_PER_SEC, rate);
330 max = min << tcbpwmc->width;
332 /* If period is too big return ERANGE error */
337 duty = div_u64(duty_ns, min);
338 period = div_u64(period_ns, min);
341 atcbpwm = tcbpwmc->pwms[1];
343 atcbpwm = tcbpwmc->pwms[0];
346 * PWM devices provided by the TCB driver are grouped by 2.
347 * PWM devices in a given group must be configured with the
350 * We're checking the period value of the second PWM device
351 * in this group before applying the new config.
353 if ((atcbpwm && atcbpwm->duty > 0 &&
354 atcbpwm->duty != atcbpwm->period) &&
355 (atcbpwm->div != i || atcbpwm->period != period)) {
357 "failed to configure period_ns: PWM group already configured with a different value\n");
361 tcbpwm->period = period;
368 static int atmel_tcb_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
369 const struct pwm_state *state)
371 int duty_cycle, period;
374 /* This function only sets a flag in driver data */
375 atmel_tcb_pwm_set_polarity(chip, pwm, state->polarity);
377 if (!state->enabled) {
378 atmel_tcb_pwm_disable(chip, pwm);
382 period = state->period < INT_MAX ? state->period : INT_MAX;
383 duty_cycle = state->duty_cycle < INT_MAX ? state->duty_cycle : INT_MAX;
385 ret = atmel_tcb_pwm_config(chip, pwm, duty_cycle, period);
389 return atmel_tcb_pwm_enable(chip, pwm);
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,
399 static struct atmel_tcb_config tcb_rm9200_config = {
403 static struct atmel_tcb_config tcb_sam9x5_config = {
407 static struct atmel_tcb_config tcb_sama5d2_config = {
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, },
419 static int atmel_tcb_pwm_probe(struct platform_device *pdev)
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";
432 err = of_property_read_u32(np, "reg", &channel);
435 "failed to get Timer Counter Block channel from device tree (error: %d)\n",
440 regmap = syscon_node_to_regmap(np->parent);
442 return PTR_ERR(regmap);
444 slow_clk = of_clk_get_by_name(np->parent, "slow_clk");
445 if (IS_ERR(slow_clk))
446 return PTR_ERR(slow_clk);
448 clk_name[1] += channel;
449 clk = of_clk_get_by_name(np->parent, clk_name);
451 clk = of_clk_get_by_name(np->parent, "t0_clk");
455 match = of_match_node(atmel_tcb_of_match, np->parent);
456 config = match->data;
458 if (config->has_gclk) {
459 gclk = of_clk_get_by_name(np->parent, "gclk");
461 return PTR_ERR(gclk);
464 tcbpwm = devm_kzalloc(&pdev->dev, sizeof(*tcbpwm), GFP_KERNEL);
465 if (tcbpwm == NULL) {
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;
477 tcbpwm->slow_clk = slow_clk;
478 tcbpwm->width = config->counter_width;
480 err = clk_prepare_enable(slow_clk);
484 spin_lock_init(&tcbpwm->lock);
486 err = pwmchip_add(&tcbpwm->chip);
488 goto err_disable_clk;
490 platform_set_drvdata(pdev, tcbpwm);
495 clk_disable_unprepare(tcbpwm->slow_clk);
503 static int atmel_tcb_pwm_remove(struct platform_device *pdev)
505 struct atmel_tcb_pwm_chip *tcbpwm = platform_get_drvdata(pdev);
507 pwmchip_remove(&tcbpwm->chip);
509 clk_disable_unprepare(tcbpwm->slow_clk);
510 clk_put(tcbpwm->slow_clk);
511 clk_put(tcbpwm->clk);
516 static const struct of_device_id atmel_tcb_pwm_dt_ids[] = {
517 { .compatible = "atmel,tcb-pwm", },
520 MODULE_DEVICE_TABLE(of, atmel_tcb_pwm_dt_ids);
522 #ifdef CONFIG_PM_SLEEP
523 static int atmel_tcb_pwm_suspend(struct device *dev)
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;
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);
537 static int atmel_tcb_pwm_resume(struct device *dev)
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;
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);
549 regmap_write(tcbpwm->regmap,
550 ATMEL_TC_CLKEN | ATMEL_TC_SWTRG,
551 ATMEL_TC_REG(channel, CCR));
557 static SIMPLE_DEV_PM_OPS(atmel_tcb_pwm_pm_ops, atmel_tcb_pwm_suspend,
558 atmel_tcb_pwm_resume);
560 static struct platform_driver atmel_tcb_pwm_driver = {
562 .name = "atmel-tcb-pwm",
563 .of_match_table = atmel_tcb_pwm_dt_ids,
564 .pm = &atmel_tcb_pwm_pm_ops,
566 .probe = atmel_tcb_pwm_probe,
567 .remove = atmel_tcb_pwm_remove,
569 module_platform_driver(atmel_tcb_pwm_driver);
571 MODULE_AUTHOR("Boris BREZILLON <b.brezillon@overkiz.com>");
572 MODULE_DESCRIPTION("Atmel Timer Counter Pulse Width Modulation Driver");
573 MODULE_LICENSE("GPL v2");