2 * drivers/pwm/atmel-pwm.c
4 * Copyright (C) 2010 Bill Gatliff <bgat@billgatliff.com>
5 * Copyright (C) 2007 David Brownell
7 * This program is free software; you may redistribute and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
11 * This program is distributed in the hope that it will be useful, but
12 * WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
22 #include <linux/module.h>
23 #include <linux/init.h>
24 #include <linux/clk.h>
25 #include <linux/err.h>
27 #include <linux/interrupt.h>
28 #include <linux/platform_device.h>
29 #include <linux/slab.h>
30 #include <linux/pwm/pwm.h>
33 /* registers common to the PWMC peripheral */
43 /* registers per each PWMC channel */
50 /* how to find each channel */
51 PWMC_CHAN_BASE = 0x200,
52 PWMC_CHAN_STRIDE = 0x20,
54 /* CMR bits of interest */
58 PWMC_CMR_CPRE_MASK = 0xf,
62 struct pwm_device pwm;
71 static inline struct atmel_pwm *to_atmel_pwm(const struct pwm_channel *p)
73 return container_of(p->pwm, struct atmel_pwm, pwm);
77 pwmc_writel(const struct atmel_pwm *p,
78 unsigned offset, u32 val)
80 __raw_writel(val, p->iobase + offset);
84 pwmc_readl(const struct atmel_pwm *p,
87 return __raw_readl(p->iobase + offset);
91 pwmc_chan_writel(const struct pwm_channel *p,
94 const struct atmel_pwm *ap = to_atmel_pwm(p);
96 if (PWMC_CMR == offset)
97 val &= ((1 << PWMC_CMR_CPD)
98 | (1 << PWMC_CMR_CPOL)
99 | (1 << PWMC_CMR_CALG)
100 | (PWMC_CMR_CPRE_MASK));
102 val &= ap->ccnt_mask;
104 pwmc_writel(ap, offset + PWMC_CHAN_BASE
105 + (p->chan * PWMC_CHAN_STRIDE), val);
109 pwmc_chan_readl(const struct pwm_channel *p,
112 const struct atmel_pwm *ap = to_atmel_pwm(p);
114 return pwmc_readl(ap, offset + PWMC_CHAN_BASE
115 + (p->chan * PWMC_CHAN_STRIDE));
119 __atmel_pwm_is_on(struct pwm_channel *p)
121 struct atmel_pwm *ap = to_atmel_pwm(p);
122 return (pwmc_readl(ap, PWMC_SR) & (1 << p->chan)) ? 1 : 0;
126 __atmel_pwm_unsynchronize(struct pwm_channel *p,
127 struct pwm_channel *to_p)
129 const struct atmel_pwm *ap = to_atmel_pwm(p);
133 ap->sync_mask[p->chan] &= ~(1 << to_p->chan);
134 ap->sync_mask[to_p->chan] &= ~(1 << p->chan);
138 ap->sync_mask[p->chan] = 0;
139 for (wchan = 0; wchan < ap->pwm.nchan; wchan++)
140 ap->sync_mask[wchan] &= ~(1 << p->chan);
142 dev_dbg(p->pwm->dev, "sync_mask %x\n", ap->sync_mask[p->chan]);
146 __atmel_pwm_synchronize(struct pwm_channel *p,
147 struct pwm_channel *to_p)
149 const struct atmel_pwm *ap = to_atmel_pwm(p);
154 ap->sync_mask[p->chan] |= (1 << to_p->chan);
155 ap->sync_mask[to_p->chan] |= (1 << p->chan);
157 dev_dbg(p->pwm->dev, "sync_mask %x\n", ap->sync_mask[p->chan]);
161 __atmel_pwm_stop(struct pwm_channel *p)
163 struct atmel_pwm *ap = to_atmel_pwm(p);
164 u32 chid = 1 << p->chan;
166 pwmc_writel(ap, PWMC_DIS, ap->sync_mask[p->chan] | chid);
170 __atmel_pwm_start(struct pwm_channel *p)
172 struct atmel_pwm *ap = to_atmel_pwm(p);
173 u32 chid = 1 << p->chan;
175 pwmc_writel(ap, PWMC_ENA, ap->sync_mask[p->chan] | chid);
179 atmel_pwm_synchronize(struct pwm_channel *p,
180 struct pwm_channel *to_p)
183 spin_lock_irqsave(&p->lock, flags);
184 __atmel_pwm_synchronize(p, to_p);
185 spin_unlock_irqrestore(&p->lock, flags);
190 atmel_pwm_unsynchronize(struct pwm_channel *p,
191 struct pwm_channel *from_p)
194 spin_lock_irqsave(&p->lock, flags);
195 __atmel_pwm_unsynchronize(p, from_p);
196 spin_unlock_irqrestore(&p->lock, flags);
201 __atmel_pwm_config_polarity(struct pwm_channel *p,
202 struct pwm_channel_config *c)
204 u32 cmr = pwmc_chan_readl(p, PWMC_CMR);
207 cmr &= ~BIT(PWMC_CMR_CPOL);
209 cmr |= BIT(PWMC_CMR_CPOL);
210 pwmc_chan_writel(p, PWMC_CMR, cmr);
211 p->active_high = c->polarity ? 1 : 0;
213 dev_dbg(p->pwm->dev, "polarity %d\n", c->polarity);
218 __atmel_pwm_config_duty_ticks(struct pwm_channel *p,
219 struct pwm_channel_config *c)
221 u32 cmr, cprd, cpre, cdty;
223 cmr = pwmc_chan_readl(p, PWMC_CMR);
224 cprd = pwmc_chan_readl(p, PWMC_CPRD);
226 cpre = cmr & PWMC_CMR_CPRE_MASK;
227 cmr &= ~BIT(PWMC_CMR_CPD);
229 cdty = cprd - (c->duty_ticks >> cpre);
231 p->duty_ticks = c->duty_ticks;
233 if (__atmel_pwm_is_on(p)) {
234 pwmc_chan_writel(p, PWMC_CMR, cmr);
235 pwmc_chan_writel(p, PWMC_CUPD, cdty);
237 pwmc_chan_writel(p, PWMC_CDTY, cdty);
239 dev_dbg(p->pwm->dev, "duty_ticks = %lu cprd = %x"
240 " cdty = %x cpre = %x\n", p->duty_ticks,
247 __atmel_pwm_config_period_ticks(struct pwm_channel *p,
248 struct pwm_channel_config *c)
252 cpre = fls(c->period_ticks);
261 cmr = pwmc_chan_readl(p, PWMC_CMR);
262 cmr &= ~PWMC_CMR_CPRE_MASK;
265 cprd = c->period_ticks >> cpre;
267 pwmc_chan_writel(p, PWMC_CMR, cmr);
268 pwmc_chan_writel(p, PWMC_CPRD, cprd);
269 p->period_ticks = c->period_ticks;
271 dev_dbg(p->pwm->dev, "period_ticks = %lu cprd = %x cpre = %x\n",
272 p->period_ticks, cprd, cpre);
278 atmel_pwm_config_nosleep(struct pwm_channel *p,
279 struct pwm_channel_config *c)
284 spin_lock_irqsave(&p->lock, flags);
286 switch (c->config_mask) {
288 case PWM_CONFIG_DUTY_TICKS:
289 __atmel_pwm_config_duty_ticks(p, c);
292 case PWM_CONFIG_STOP:
296 case PWM_CONFIG_START:
297 __atmel_pwm_start(p);
300 case PWM_CONFIG_POLARITY:
301 __atmel_pwm_config_polarity(p, c);
309 spin_unlock_irqrestore(&p->lock, flags);
314 atmel_pwm_stop_sync(struct pwm_channel *p)
316 struct atmel_pwm *ap = container_of(p->pwm, struct atmel_pwm, pwm);
318 int was_on = __atmel_pwm_is_on(p);
322 init_completion(&p->complete);
323 set_bit(FLAG_STOP, &p->flags);
324 pwmc_writel(ap, PWMC_IER, 1 << p->chan);
326 dev_dbg(p->pwm->dev, "waiting on stop_sync completion...\n");
328 ret = wait_for_completion_interruptible(&p->complete);
330 dev_dbg(p->pwm->dev, "stop_sync complete (%d)\n", ret);
334 } while (p->flags & BIT(FLAG_STOP));
341 atmel_pwm_config(struct pwm_channel *p,
342 struct pwm_channel_config *c)
346 if (p->pwm->config_nosleep) {
347 if (!p->pwm->config_nosleep(p, c))
353 dev_dbg(p->pwm->dev, "config_mask %x\n", c->config_mask);
355 was_on = atmel_pwm_stop_sync(p);
359 if (c->config_mask & PWM_CONFIG_PERIOD_TICKS) {
360 __atmel_pwm_config_period_ticks(p, c);
361 if (!(c->config_mask & PWM_CONFIG_DUTY_TICKS)) {
362 struct pwm_channel_config d = {
363 .config_mask = PWM_CONFIG_DUTY_TICKS,
364 .duty_ticks = p->duty_ticks,
366 __atmel_pwm_config_duty_ticks(p, &d);
370 if (c->config_mask & PWM_CONFIG_DUTY_TICKS)
371 __atmel_pwm_config_duty_ticks(p, c);
373 if (c->config_mask & PWM_CONFIG_POLARITY)
374 __atmel_pwm_config_polarity(p, c);
376 if ((c->config_mask & PWM_CONFIG_START)
377 || (was_on && !(c->config_mask & PWM_CONFIG_STOP)))
378 __atmel_pwm_start(p);
384 __atmel_pwm_set_callback(struct pwm_channel *p,
385 pwm_callback_t callback)
387 struct atmel_pwm *ap = container_of(p->pwm, struct atmel_pwm, pwm);
389 p->callback = callback;
390 pwmc_writel(ap, p->callback ? PWMC_IER : PWMC_IDR, 1 << p->chan);
394 atmel_pwm_set_callback(struct pwm_channel *p,
395 pwm_callback_t callback)
397 struct atmel_pwm *ap = to_atmel_pwm(p);
400 spin_lock_irqsave(&ap->lock, flags);
401 __atmel_pwm_set_callback(p, callback);
402 spin_unlock_irqrestore(&ap->lock, flags);
408 atmel_pwm_request(struct pwm_channel *p)
410 struct atmel_pwm *ap = to_atmel_pwm(p);
413 spin_lock_irqsave(&p->lock, flags);
415 p->tick_hz = clk_get_rate(ap->clk);
416 __atmel_pwm_unsynchronize(p, NULL);
418 spin_unlock_irqrestore(&p->lock, flags);
424 atmel_pwm_free(struct pwm_channel *p)
426 struct atmel_pwm *ap = to_atmel_pwm(p);
427 clk_disable(ap->clk);
431 atmel_pwmc_irq(int irq, void *data)
433 struct atmel_pwm *ap = data;
434 struct pwm_channel *p;
439 spin_lock_irqsave(&ap->lock, flags);
441 isr = pwmc_readl(ap, PWMC_ISR);
442 for (chid = 0; isr; chid++, isr >>= 1) {
443 p = &ap->pwm.channels[chid];
447 if (p->flags & BIT(FLAG_STOP)) {
449 clear_bit(FLAG_STOP, &p->flags);
451 complete_all(&p->complete);
455 spin_unlock_irqrestore(&ap->lock, flags);
461 atmel_pwmc_probe(struct platform_device *pdev)
463 struct atmel_pwm *ap;
464 struct resource *r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
467 ap = kzalloc(sizeof(*ap), GFP_KERNEL);
470 goto err_atmel_pwm_alloc;
473 spin_lock_init(&ap->lock);
474 platform_set_drvdata(pdev, ap);
476 ap->pwm.dev = &pdev->dev;
477 ap->pwm.bus_id = dev_name(&pdev->dev);
479 ap->pwm.nchan = 4; /* TODO: true only for SAM9263 and AP7000 */
480 ap->ccnt_mask = 0xffffUL; /* TODO: true only for SAM9263 */
482 ap->sync_mask = kzalloc(ap->pwm.nchan * sizeof(u32), GFP_KERNEL);
483 if (!ap->sync_mask) {
485 goto err_alloc_sync_masks;
488 ap->pwm.owner = THIS_MODULE;
489 ap->pwm.request = atmel_pwm_request;
490 ap->pwm.free = atmel_pwm_free;
491 ap->pwm.config_nosleep = atmel_pwm_config_nosleep;
492 ap->pwm.config = atmel_pwm_config;
493 ap->pwm.synchronize = atmel_pwm_synchronize;
494 ap->pwm.unsynchronize = atmel_pwm_unsynchronize;
495 ap->pwm.set_callback = atmel_pwm_set_callback;
497 ap->clk = clk_get(&pdev->dev, "pwm_clk");
498 if (PTR_ERR(ap->clk)) {
503 ap->iobase = ioremap_nocache(r->start, r->end - r->start + 1);
510 pwmc_writel(ap, PWMC_DIS, -1);
511 pwmc_writel(ap, PWMC_IDR, -1);
512 clk_disable(ap->clk);
514 ap->irq = platform_get_irq(pdev, 0);
515 if (ap->irq != -ENXIO) {
516 ret = request_irq(ap->irq, atmel_pwmc_irq, 0,
519 goto err_request_irq;
522 ret = pwm_register(&ap->pwm);
524 goto err_pwm_register;
529 if (ap->irq != -ENXIO)
530 free_irq(ap->irq, ap);
536 platform_set_drvdata(pdev, NULL);
537 err_alloc_sync_masks:
544 atmel_pwmc_remove(struct platform_device *pdev)
546 struct atmel_pwm *ap = platform_get_drvdata(pdev);
549 /* TODO: what can we do if this fails? */
550 ret = pwm_unregister(&ap->pwm);
553 pwmc_writel(ap, PWMC_IDR, -1);
554 pwmc_writel(ap, PWMC_DIS, -1);
555 clk_disable(ap->clk);
557 if (ap->irq != -ENXIO)
558 free_irq(ap->irq, ap);
568 static struct platform_driver atmel_pwm_driver = {
570 .name = "atmel_pwmc",
571 .owner = THIS_MODULE,
573 .probe = atmel_pwmc_probe,
574 .remove = __devexit_p(atmel_pwmc_remove),
577 static int __init atmel_pwm_init(void)
579 return platform_driver_register(&atmel_pwm_driver);
581 module_init(atmel_pwm_init);
583 static void __exit atmel_pwm_exit(void)
585 platform_driver_unregister(&atmel_pwm_driver);
587 module_exit(atmel_pwm_exit);
589 MODULE_AUTHOR("Bill Gatliff <bgat@billgatliff.com>");
590 MODULE_DESCRIPTION("Driver for Atmel PWMC peripheral");
591 MODULE_LICENSE("GPL");
592 MODULE_ALIAS("platform:atmel_pwmc");