summaryrefslogtreecommitdiffstats
path: root/drivers/pwm/pwm-tiehrpwm.c
blob: aee4471424d14a98da494f877909ae5e9f804990 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
/*
 * EHRPWM PWM driver
 *
 * Copyright (C) 2012 Texas Instruments, Inc. - http://www.ti.com/
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/pwm.h>
#include <linux/io.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/pm_runtime.h>
#include <linux/of_device.h>

#include "pwm-tipwmss.h"

/* EHRPWM registers and bits definitions */

/* Time base module registers */
#define TBCTL			0x00
#define TBPRD			0x0A

#define TBCTL_RUN_MASK		(BIT(15) | BIT(14))
#define TBCTL_STOP_NEXT		0
#define TBCTL_STOP_ON_CYCLE	BIT(14)
#define TBCTL_FREE_RUN		(BIT(15) | BIT(14))
#define TBCTL_PRDLD_MASK	BIT(3)
#define TBCTL_PRDLD_SHDW	0
#define TBCTL_PRDLD_IMDT	BIT(3)
#define TBCTL_CLKDIV_MASK	(BIT(12) | BIT(11) | BIT(10) | BIT(9) | \
				BIT(8) | BIT(7))
#define TBCTL_CTRMODE_MASK	(BIT(1) | BIT(0))
#define TBCTL_CTRMODE_UP	0
#define TBCTL_CTRMODE_DOWN	BIT(0)
#define TBCTL_CTRMODE_UPDOWN	BIT(1)
#define TBCTL_CTRMODE_FREEZE	(BIT(1) | BIT(0))

#define TBCTL_HSPCLKDIV_SHIFT	7
#define TBCTL_CLKDIV_SHIFT	10

#define CLKDIV_MAX		7
#define HSPCLKDIV_MAX		7
#define PERIOD_MAX		0xFFFF

/* compare module registers */
#define CMPA			0x12
#define CMPB			0x14

/* Action qualifier module registers */
#define AQCTLA			0x16
#define AQCTLB			0x18
#define AQSFRC			0x1A
#define AQCSFRC			0x1C

#define AQCTL_CBU_MASK		(BIT(9) | BIT(8))
#define AQCTL_CBU_FRCLOW	BIT(8)
#define AQCTL_CBU_FRCHIGH	BIT(9)
#define AQCTL_CBU_FRCTOGGLE	(BIT(9) | BIT(8))
#define AQCTL_CAU_MASK		(BIT(5) | BIT(4))
#define AQCTL_CAU_FRCLOW	BIT(4)
#define AQCTL_CAU_FRCHIGH	BIT(5)
#define AQCTL_CAU_FRCTOGGLE	(BIT(5) | BIT(4))
#define AQCTL_PRD_MASK		(BIT(3) | BIT(2))
#define AQCTL_PRD_FRCLOW	BIT(2)
#define AQCTL_PRD_FRCHIGH	BIT(3)
#define AQCTL_PRD_FRCTOGGLE	(BIT(3) | BIT(2))
#define AQCTL_ZRO_MASK		(BIT(1) | BIT(0))
#define AQCTL_ZRO_FRCLOW	BIT(0)
#define AQCTL_ZRO_FRCHIGH	BIT(1)
#define AQCTL_ZRO_FRCTOGGLE	(BIT(1) | BIT(0))

#define AQCTL_CHANA_POLNORMAL	(AQCTL_CAU_FRCLOW | AQCTL_PRD_FRCHIGH | \
				AQCTL_ZRO_FRCHIGH)
#define AQCTL_CHANA_POLINVERSED	(AQCTL_CAU_FRCHIGH | AQCTL_PRD_FRCLOW | \
				AQCTL_ZRO_FRCLOW)
#define AQCTL_CHANB_POLNORMAL	(AQCTL_CBU_FRCLOW | AQCTL_PRD_FRCHIGH | \
				AQCTL_ZRO_FRCHIGH)
#define AQCTL_CHANB_POLINVERSED	(AQCTL_CBU_FRCHIGH | AQCTL_PRD_FRCLOW | \
				AQCTL_ZRO_FRCLOW)

#define AQSFRC_RLDCSF_MASK	(BIT(7) | BIT(6))
#define AQSFRC_RLDCSF_ZRO	0
#define AQSFRC_RLDCSF_PRD	BIT(6)
#define AQSFRC_RLDCSF_ZROPRD	BIT(7)
#define AQSFRC_RLDCSF_IMDT	(BIT(7) | BIT(6))

#define AQCSFRC_CSFB_MASK	(BIT(3) | BIT(2))
#define AQCSFRC_CSFB_FRCDIS	0
#define AQCSFRC_CSFB_FRCLOW	BIT(2)
#define AQCSFRC_CSFB_FRCHIGH	BIT(3)
#define AQCSFRC_CSFB_DISSWFRC	(BIT(3) | BIT(2))
#define AQCSFRC_CSFA_MASK	(BIT(1) | BIT(0))
#define AQCSFRC_CSFA_FRCDIS	0
#define AQCSFRC_CSFA_FRCLOW	BIT(0)
#define AQCSFRC_CSFA_FRCHIGH	BIT(1)
#define AQCSFRC_CSFA_DISSWFRC	(BIT(1) | BIT(0))

#define NUM_PWM_CHANNEL		2	/* EHRPWM channels */

struct ehrpwm_context {
	u16 tbctl;
	u16 tbprd;
	u16 cmpa;
	u16 cmpb;
	u16 aqctla;
	u16 aqctlb;
	u16 aqsfrc;
	u16 aqcsfrc;
};

struct ehrpwm_pwm_chip {
	struct pwm_chip	chip;
	unsigned int	clk_rate;
	void __iomem	*mmio_base;
	unsigned long period_cycles[NUM_PWM_CHANNEL];
	enum pwm_polarity polarity[NUM_PWM_CHANNEL];
	struct	clk	*tbclk;
	struct ehrpwm_context ctx;
};

static inline struct ehrpwm_pwm_chip *to_ehrpwm_pwm_chip(struct pwm_chip *chip)
{
	return container_of(chip, struct ehrpwm_pwm_chip, chip);
}

static u16 ehrpwm_read(void __iomem *base, int offset)
{
	return readw(base + offset);
}

static void ehrpwm_write(void __iomem *base, int offset, unsigned int val)
{
	writew(val & 0xFFFF, base + offset);
}

static void ehrpwm_modify(void __iomem *base, int offset,
		unsigned short mask, unsigned short val)
{
	unsigned short regval;

	regval = readw(base + offset);
	regval &= ~mask;
	regval |= val & mask;
	writew(regval, base + offset);
}

/**
 * set_prescale_div -	Set up the prescaler divider function
 * @rqst_prescaler:	prescaler value min
 * @prescale_div:	prescaler value set
 * @tb_clk_div:		Time Base Control prescaler bits
 */
static int set_prescale_div(unsigned long rqst_prescaler,
		unsigned short *prescale_div, unsigned short *tb_clk_div)
{
	unsigned int clkdiv, hspclkdiv;

	for (clkdiv = 0; clkdiv <= CLKDIV_MAX; clkdiv++) {
		for (hspclkdiv = 0; hspclkdiv <= HSPCLKDIV_MAX; hspclkdiv++) {

			/*
			 * calculations for prescaler value :
			 * prescale_div = HSPCLKDIVIDER * CLKDIVIDER.
			 * HSPCLKDIVIDER =  2 ** hspclkdiv
			 * CLKDIVIDER = (1),		if clkdiv == 0 *OR*
			 *		(2 * clkdiv),	if clkdiv != 0
			 *
			 * Configure prescale_div value such that period
			 * register value is less than 65535.
			 */

			*prescale_div = (1 << clkdiv) *
					(hspclkdiv ? (hspclkdiv * 2) : 1);
			if (*prescale_div > rqst_prescaler) {
				*tb_clk_div = (clkdiv << TBCTL_CLKDIV_SHIFT) |
					(hspclkdiv << TBCTL_HSPCLKDIV_SHIFT);
				return 0;
			}
		}
	}
	return 1;
}

static void configure_polarity(struct ehrpwm_pwm_chip *pc, int chan)
{
	int aqctl_reg;
	unsigned short aqctl_val, aqctl_mask;

	/*
	 * Configure PWM output to HIGH/LOW level on counter
	 * reaches compare register value and LOW/HIGH level
	 * on counter value reaches period register value and
	 * zero value on counter
	 */
	if (chan == 1) {
		aqctl_reg = AQCTLB;
		aqctl_mask = AQCTL_CBU_MASK;

		if (pc->polarity[chan] == PWM_POLARITY_INVERSED)
			aqctl_val = AQCTL_CHANB_POLINVERSED;
		else
			aqctl_val = AQCTL_CHANB_POLNORMAL;
	} else {
		aqctl_reg = AQCTLA;
		aqctl_mask = AQCTL_CAU_MASK;

		if (pc->polarity[chan] == PWM_POLARITY_INVERSED)
			aqctl_val = AQCTL_CHANA_POLINVERSED;
		else
			aqctl_val = AQCTL_CHANA_POLNORMAL;
	}

	aqctl_mask |= AQCTL_PRD_MASK | AQCTL_ZRO_MASK;
	ehrpwm_modify(pc->mmio_base, aqctl_reg, aqctl_mask, aqctl_val);
}

/*
 * period_ns = 10^9 * (ps_divval * period_cycles) / PWM_CLK_RATE
 * duty_ns   = 10^9 * (ps_divval * duty_cycles) / PWM_CLK_RATE
 */
static int ehrpwm_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
		int duty_ns, int period_ns)
{
	struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
	unsigned long long c;
	unsigned long period_cycles, duty_cycles;
	unsigned short ps_divval, tb_divval;
	int i, cmp_reg;

	if (period_ns > NSEC_PER_SEC)
		return -ERANGE;

	c = pc->clk_rate;
	c = c * period_ns;
	do_div(c, NSEC_PER_SEC);
	period_cycles = (unsigned long)c;

	if (period_cycles < 1) {
		period_cycles = 1;
		duty_cycles = 1;
	} else {
		c = pc->clk_rate;
		c = c * duty_ns;
		do_div(c, NSEC_PER_SEC);
		duty_cycles = (unsigned long)c;
	}

	/*
	 * Period values should be same for multiple PWM channels as IP uses
	 * same period register for multiple channels.
	 */
	for (i = 0; i < NUM_PWM_CHANNEL; i++) {
		if (pc->period_cycles[i] &&
				(pc->period_cycles[i] != period_cycles)) {
			/*
			 * Allow channel to reconfigure period if no other
			 * channels being configured.
			 */
			if (i == pwm->hwpwm)
				continue;

			dev_err(chip->dev, "Period value conflicts with channel %d\n",
					i);
			return -EINVAL;
		}
	}

	pc->period_cycles[pwm->hwpwm] = period_cycles;

	/* Configure clock prescaler to support Low frequency PWM wave */
	if (set_prescale_div(period_cycles/PERIOD_MAX, &ps_divval,
				&tb_divval)) {
		dev_err(chip->dev, "Unsupported values\n");
		return -EINVAL;
	}

	pm_runtime_get_sync(chip->dev);

	/* Update clock prescaler values */
	ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_CLKDIV_MASK, tb_divval);

	/* Update period & duty cycle with presacler division */
	period_cycles = period_cycles / ps_divval;
	duty_cycles = duty_cycles / ps_divval;

	/* Configure shadow loading on Period register */
	ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_PRDLD_MASK, TBCTL_PRDLD_SHDW);

	ehrpwm_write(pc->mmio_base, TBPRD, period_cycles);

	/* Configure ehrpwm counter for up-count mode */
	ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_CTRMODE_MASK,
			TBCTL_CTRMODE_UP);

	if (pwm->hwpwm == 1)
		/* Channel 1 configured with compare B register */
		cmp_reg = CMPB;
	else
		/* Channel 0 configured with compare A register */
		cmp_reg = CMPA;

	ehrpwm_write(pc->mmio_base, cmp_reg, duty_cycles);

	pm_runtime_put_sync(chip->dev);
	return 0;
}

static int ehrpwm_pwm_set_polarity(struct pwm_chip *chip,
		struct pwm_device *pwm,	enum pwm_polarity polarity)
{
	struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);

	/* Configuration of polarity in hardware delayed, do at enable */
	pc->polarity[pwm->hwpwm] = polarity;
	return 0;
}

static int ehrpwm_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
{
	struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
	unsigned short aqcsfrc_val, aqcsfrc_mask;
	int ret;

	/* Leave clock enabled on enabling PWM */
	pm_runtime_get_sync(chip->dev);

	/* Disabling Action Qualifier on PWM output */
	if (pwm->hwpwm) {
		aqcsfrc_val = AQCSFRC_CSFB_FRCDIS;
		aqcsfrc_mask = AQCSFRC_CSFB_MASK;
	} else {
		aqcsfrc_val = AQCSFRC_CSFA_FRCDIS;
		aqcsfrc_mask = AQCSFRC_CSFA_MASK;
	}

	/* Changes to shadow mode */
	ehrpwm_modify(pc->mmio_base, AQSFRC, AQSFRC_RLDCSF_MASK,
			AQSFRC_RLDCSF_ZRO);

	ehrpwm_modify(pc->mmio_base, AQCSFRC, aqcsfrc_mask, aqcsfrc_val);

	/* Channels polarity can be configured from action qualifier module */
	configure_polarity(pc, pwm->hwpwm);

	/* Enable TBCLK before enabling PWM device */
	ret = clk_enable(pc->tbclk);
	if (ret) {
		dev_err(chip->dev, "Failed to enable TBCLK for %s\n",
			dev_name(pc->chip.dev));
		return ret;
	}

	/* Enable time counter for free_run */
	ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_RUN_MASK, TBCTL_FREE_RUN);
	return 0;
}

static void ehrpwm_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
{
	struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
	unsigned short aqcsfrc_val, aqcsfrc_mask;

	/* Action Qualifier puts PWM output low forcefully */
	if (pwm->hwpwm) {
		aqcsfrc_val = AQCSFRC_CSFB_FRCLOW;
		aqcsfrc_mask = AQCSFRC_CSFB_MASK;
	} else {
		aqcsfrc_val = AQCSFRC_CSFA_FRCLOW;
		aqcsfrc_mask = AQCSFRC_CSFA_MASK;
	}

	/*
	 * Changes to immediate action on Action Qualifier. This puts
	 * Action Qualifier control on PWM output from next TBCLK
	 */
	ehrpwm_modify(pc->mmio_base, AQSFRC, AQSFRC_RLDCSF_MASK,
			AQSFRC_RLDCSF_IMDT);

	ehrpwm_modify(pc->mmio_base, AQCSFRC, aqcsfrc_mask, aqcsfrc_val);

	/* Disabling TBCLK on PWM disable */
	clk_disable(pc->tbclk);

	/* Stop Time base counter */
	ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_RUN_MASK, TBCTL_STOP_NEXT);

	/* Disable clock on PWM disable */
	pm_runtime_put_sync(chip->dev);
}

static void ehrpwm_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
{
	struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);

	if (test_bit(PWMF_ENABLED, &pwm->flags)) {
		dev_warn(chip->dev, "Removing PWM device without disabling\n");
		pm_runtime_put_sync(chip->dev);
	}

	/* set period value to zero on free */
	pc->period_cycles[pwm->hwpwm] = 0;
}

static const struct pwm_ops ehrpwm_pwm_ops = {
	.free		= ehrpwm_pwm_free,
	.config		= ehrpwm_pwm_config,
	.set_polarity	= ehrpwm_pwm_set_polarity,
	.enable		= ehrpwm_pwm_enable,
	.disable	= ehrpwm_pwm_disable,
	.owner		= THIS_MODULE,
};

static const struct of_device_id ehrpwm_of_match[] = {
	{ .compatible	= "ti,am33xx-ehrpwm" },
	{},
};
MODULE_DEVICE_TABLE(of, ehrpwm_of_match);

static int ehrpwm_pwm_probe(struct platform_device *pdev)
{
	int ret;
	struct resource *r;
	struct clk *clk;
	struct ehrpwm_pwm_chip *pc;
	u16 status;

	pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);
	if (!pc) {
		dev_err(&pdev->dev, "failed to allocate memory\n");
		return -ENOMEM;
	}

	clk = devm_clk_get(&pdev->dev, "fck");
	if (IS_ERR(clk)) {
		dev_err(&pdev->dev, "failed to get clock\n");
		return PTR_ERR(clk);
	}

	pc->clk_rate = clk_get_rate(clk);
	if (!pc->clk_rate) {
		dev_err(&pdev->dev, "failed to get clock rate\n");
		return -EINVAL;
	}

	pc->chip.dev = &pdev->dev;
	pc->chip.ops = &ehrpwm_pwm_ops;
	pc->chip.of_xlate = of_pwm_xlate_with_flags;
	pc->chip.of_pwm_n_cells = 3;
	pc->chip.base = -1;
	pc->chip.npwm = NUM_PWM_CHANNEL;

	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	pc->mmio_base = devm_ioremap_resource(&pdev->dev, r);
	if (IS_ERR(pc->mmio_base))
		return PTR_ERR(pc->mmio_base);

	/* Acquire tbclk for Time Base EHRPWM submodule */
	pc->tbclk = devm_clk_get(&pdev->dev, "tbclk");
	if (IS_ERR(pc->tbclk)) {
		dev_err(&pdev->dev, "Failed to get tbclk\n");
		return PTR_ERR(pc->tbclk);
	}

	ret = clk_prepare(pc->tbclk);
	if (ret < 0) {
		dev_err(&pdev->dev, "clk_prepare() failed: %d\n", ret);
		return ret;
	}

	ret = pwmchip_add(&pc->chip);
	if (ret < 0) {
		dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
		return ret;
	}

	pm_runtime_enable(&pdev->dev);
	pm_runtime_get_sync(&pdev->dev);

	status = pwmss_submodule_state_change(pdev->dev.parent,
			PWMSS_EPWMCLK_EN);
	if (!(status & PWMSS_EPWMCLK_EN_ACK)) {
		dev_err(&pdev->dev, "PWMSS config space clock enable failed\n");
		ret = -EINVAL;
		goto pwmss_clk_failure;
	}

	pm_runtime_put_sync(&pdev->dev);

	platform_set_drvdata(pdev, pc);
	return 0;

pwmss_clk_failure:
	pm_runtime_put_sync(&pdev->dev);
	pm_runtime_disable(&pdev->dev);
	pwmchip_remove(&pc->chip);
	clk_unprepare(pc->tbclk);
	return ret;
}

static int ehrpwm_pwm_remove(struct platform_device *pdev)
{
	struct ehrpwm_pwm_chip *pc = platform_get_drvdata(pdev);

	clk_unprepare(pc->tbclk);

	pm_runtime_get_sync(&pdev->dev);
	/*
	 * Due to hardware misbehaviour, acknowledge of the stop_req
	 * is missing. Hence checking of the status bit skipped.
	 */
	pwmss_submodule_state_change(pdev->dev.parent, PWMSS_EPWMCLK_STOP_REQ);
	pm_runtime_put_sync(&pdev->dev);

	pm_runtime_put_sync(&pdev->dev);
	pm_runtime_disable(&pdev->dev);
	return pwmchip_remove(&pc->chip);
}

static void ehrpwm_pwm_save_context(struct ehrpwm_pwm_chip *pc)
{
	pm_runtime_get_sync(pc->chip.dev);
	pc->ctx.tbctl = ehrpwm_read(pc->mmio_base, TBCTL);
	pc->ctx.tbprd = ehrpwm_read(pc->mmio_base, TBPRD);
	pc->ctx.cmpa = ehrpwm_read(pc->mmio_base, CMPA);
	pc->ctx.cmpb = ehrpwm_read(pc->mmio_base, CMPB);
	pc->ctx.aqctla = ehrpwm_read(pc->mmio_base, AQCTLA);
	pc->ctx.aqctlb = ehrpwm_read(pc->mmio_base, AQCTLB);
	pc->ctx.aqsfrc = ehrpwm_read(pc->mmio_base, AQSFRC);
	pc->ctx.aqcsfrc = ehrpwm_read(pc->mmio_base, AQCSFRC);
	pm_runtime_put_sync(pc->chip.dev);
}

static void ehrpwm_pwm_restore_context(struct ehrpwm_pwm_chip *pc)
{
	ehrpwm_write(pc->mmio_base, TBPRD, pc->ctx.tbprd);
	ehrpwm_write(pc->mmio_base, CMPA, pc->ctx.cmpa);
	ehrpwm_write(pc->mmio_base, CMPB, pc->ctx.cmpb);
	ehrpwm_write(pc->mmio_base, AQCTLA, pc->ctx.aqctla);
	ehrpwm_write(pc->mmio_base, AQCTLB, pc->ctx.aqctlb);
	ehrpwm_write(pc->mmio_base, AQSFRC, pc->ctx.aqsfrc);
	ehrpwm_write(pc->mmio_base, AQCSFRC, pc->ctx.aqcsfrc);
	ehrpwm_write(pc->mmio_base, TBCTL, pc->ctx.tbctl);
}

#ifdef CONFIG_PM_SLEEP
static int ehrpwm_pwm_suspend(struct device *dev)
{
	struct ehrpwm_pwm_chip *pc = dev_get_drvdata(dev);
	int i;

	ehrpwm_pwm_save_context(pc);
	for (i = 0; i < pc->chip.npwm; i++) {
		struct pwm_device *pwm = &pc->chip.pwms[i];

		if (!test_bit(PWMF_ENABLED, &pwm->flags))
			continue;

		/* Disable explicitly if PWM is running */
		pm_runtime_put_sync(dev);
	}
	return 0;
}

static int ehrpwm_pwm_resume(struct device *dev)
{
	struct ehrpwm_pwm_chip *pc = dev_get_drvdata(dev);
	int i;

	for (i = 0; i < pc->chip.npwm; i++) {
		struct pwm_device *pwm = &pc->chip.pwms[i];

		if (!test_bit(PWMF_ENABLED, &pwm->flags))
			continue;

		/* Enable explicitly if PWM was running */
		pm_runtime_get_sync(dev);
	}
	ehrpwm_pwm_restore_context(pc);
	return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(ehrpwm_pwm_pm_ops, ehrpwm_pwm_suspend,
		ehrpwm_pwm_resume);

static struct platform_driver ehrpwm_pwm_driver = {
	.driver = {
		.name	= "ehrpwm",
		.owner	= THIS_MODULE,
		.of_match_table = ehrpwm_of_match,
		.pm	= &ehrpwm_pwm_pm_ops,
	},
	.probe = ehrpwm_pwm_probe,
	.remove = ehrpwm_pwm_remove,
};

module_platform_driver(ehrpwm_pwm_driver);

MODULE_DESCRIPTION("EHRPWM PWM driver");
MODULE_AUTHOR("Texas Instruments");
MODULE_LICENSE("GPL");
OpenPOWER on IntegriCloud