xref: /linux/drivers/pwm/pwm-sti.c (revision daa121128a2d2ac6006159e2c47676e4fcd21eab)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * PWM device driver for ST SoCs
4  *
5  * Copyright (C) 2013-2016 STMicroelectronics (R&D) Limited
6  *
7  * Author: Ajit Pal Singh <ajitpal.singh@st.com>
8  *         Lee Jones <lee.jones@linaro.org>
9  */
10 
11 #include <linux/clk.h>
12 #include <linux/interrupt.h>
13 #include <linux/math64.h>
14 #include <linux/mfd/syscon.h>
15 #include <linux/module.h>
16 #include <linux/of.h>
17 #include <linux/platform_device.h>
18 #include <linux/pwm.h>
19 #include <linux/regmap.h>
20 #include <linux/sched.h>
21 #include <linux/slab.h>
22 #include <linux/time.h>
23 #include <linux/wait.h>
24 
25 #define PWM_OUT_VAL(x)	(0x00 + (4 * (x))) /* Device's Duty Cycle register */
26 #define PWM_CPT_VAL(x)	(0x10 + (4 * (x))) /* Capture value */
27 #define PWM_CPT_EDGE(x) (0x30 + (4 * (x))) /* Edge to capture on */
28 
29 #define STI_PWM_CTRL		0x50	/* Control/Config register */
30 #define STI_INT_EN		0x54	/* Interrupt Enable/Disable register */
31 #define STI_INT_STA		0x58	/* Interrupt Status register */
32 #define PWM_INT_ACK		0x5c
33 #define PWM_PRESCALE_LOW_MASK	0x0f
34 #define PWM_PRESCALE_HIGH_MASK	0xf0
35 #define PWM_CPT_EDGE_MASK	0x03
36 #define PWM_INT_ACK_MASK	0x1ff
37 
38 #define STI_MAX_CPT_DEVS	4
39 #define CPT_DC_MAX		0xff
40 
41 /* Regfield IDs */
42 enum {
43 	/* Bits in PWM_CTRL*/
44 	PWMCLK_PRESCALE_LOW,
45 	PWMCLK_PRESCALE_HIGH,
46 	CPTCLK_PRESCALE,
47 
48 	PWM_OUT_EN,
49 	PWM_CPT_EN,
50 
51 	PWM_CPT_INT_EN,
52 	PWM_CPT_INT_STAT,
53 
54 	/* Keep last */
55 	MAX_REGFIELDS
56 };
57 
58 /*
59  * Each capture input can be programmed to detect rising-edge, falling-edge,
60  * either edge or neither egde.
61  */
62 enum sti_cpt_edge {
63 	CPT_EDGE_DISABLED,
64 	CPT_EDGE_RISING,
65 	CPT_EDGE_FALLING,
66 	CPT_EDGE_BOTH,
67 };
68 
69 struct sti_cpt_ddata {
70 	u32 snapshot[3];
71 	unsigned int index;
72 	struct mutex lock;
73 	wait_queue_head_t wait;
74 };
75 
76 struct sti_pwm_chip {
77 	struct device *dev;
78 	struct clk *pwm_clk;
79 	struct clk *cpt_clk;
80 	struct regmap *regmap;
81 	unsigned int pwm_num_devs;
82 	unsigned int cpt_num_devs;
83 	unsigned int max_pwm_cnt;
84 	unsigned int max_prescale;
85 	struct sti_cpt_ddata *ddata;
86 	struct regmap_field *prescale_low;
87 	struct regmap_field *prescale_high;
88 	struct regmap_field *pwm_out_en;
89 	struct regmap_field *pwm_cpt_en;
90 	struct regmap_field *pwm_cpt_int_en;
91 	struct regmap_field *pwm_cpt_int_stat;
92 	struct pwm_device *cur;
93 	unsigned long configured;
94 	unsigned int en_count;
95 	struct mutex sti_pwm_lock; /* To sync between enable/disable calls */
96 	void __iomem *mmio;
97 };
98 
99 static const struct reg_field sti_pwm_regfields[MAX_REGFIELDS] = {
100 	[PWMCLK_PRESCALE_LOW] = REG_FIELD(STI_PWM_CTRL, 0, 3),
101 	[PWMCLK_PRESCALE_HIGH] = REG_FIELD(STI_PWM_CTRL, 11, 14),
102 	[CPTCLK_PRESCALE] = REG_FIELD(STI_PWM_CTRL, 4, 8),
103 	[PWM_OUT_EN] = REG_FIELD(STI_PWM_CTRL, 9, 9),
104 	[PWM_CPT_EN] = REG_FIELD(STI_PWM_CTRL, 10, 10),
105 	[PWM_CPT_INT_EN] = REG_FIELD(STI_INT_EN, 1, 4),
106 	[PWM_CPT_INT_STAT] = REG_FIELD(STI_INT_STA, 1, 4),
107 };
108 
109 static inline struct sti_pwm_chip *to_sti_pwmchip(struct pwm_chip *chip)
110 {
111 	return pwmchip_get_drvdata(chip);
112 }
113 
114 /*
115  * Calculate the prescaler value corresponding to the period.
116  */
117 static int sti_pwm_get_prescale(struct sti_pwm_chip *pc, unsigned long period,
118 				unsigned int *prescale)
119 {
120 	unsigned long clk_rate;
121 	unsigned long value;
122 	unsigned int ps;
123 
124 	clk_rate = clk_get_rate(pc->pwm_clk);
125 	if (!clk_rate) {
126 		dev_err(pc->dev, "failed to get clock rate\n");
127 		return -EINVAL;
128 	}
129 
130 	/*
131 	 * prescale = ((period_ns * clk_rate) / (10^9 * (max_pwm_cnt + 1)) - 1
132 	 */
133 	value = NSEC_PER_SEC / clk_rate;
134 	value *= pc->max_pwm_cnt + 1;
135 
136 	if (period % value)
137 		return -EINVAL;
138 
139 	ps  = period / value - 1;
140 	if (ps > pc->max_prescale)
141 		return -EINVAL;
142 
143 	*prescale = ps;
144 
145 	return 0;
146 }
147 
148 /*
149  * For STiH4xx PWM IP, the PWM period is fixed to 256 local clock cycles. The
150  * only way to change the period (apart from changing the PWM input clock) is
151  * to change the PWM clock prescaler.
152  *
153  * The prescaler is of 8 bits, so 256 prescaler values and hence 256 possible
154  * period values are supported (for a particular clock rate). The requested
155  * period will be applied only if it matches one of these 256 values.
156  */
157 static int sti_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
158 			  int duty_ns, int period_ns)
159 {
160 	struct sti_pwm_chip *pc = to_sti_pwmchip(chip);
161 	unsigned int ncfg, value, prescale = 0;
162 	struct pwm_device *cur = pc->cur;
163 	struct device *dev = pc->dev;
164 	bool period_same = false;
165 	int ret;
166 
167 	ncfg = hweight_long(pc->configured);
168 	if (ncfg)
169 		period_same = (period_ns == pwm_get_period(cur));
170 
171 	/*
172 	 * Allow configuration changes if one of the following conditions
173 	 * satisfy.
174 	 * 1. No devices have been configured.
175 	 * 2. Only one device has been configured and the new request is for
176 	 *    the same device.
177 	 * 3. Only one device has been configured and the new request is for
178 	 *    a new device and period of the new device is same as the current
179 	 *    configured period.
180 	 * 4. More than one devices are configured and period of the new
181 	 *    requestis the same as the current period.
182 	 */
183 	if (!ncfg ||
184 	    ((ncfg == 1) && (pwm->hwpwm == cur->hwpwm)) ||
185 	    ((ncfg == 1) && (pwm->hwpwm != cur->hwpwm) && period_same) ||
186 	    ((ncfg > 1) && period_same)) {
187 		/* Enable clock before writing to PWM registers. */
188 		ret = clk_enable(pc->pwm_clk);
189 		if (ret)
190 			return ret;
191 
192 		ret = clk_enable(pc->cpt_clk);
193 		if (ret)
194 			return ret;
195 
196 		if (!period_same) {
197 			ret = sti_pwm_get_prescale(pc, period_ns, &prescale);
198 			if (ret)
199 				goto clk_dis;
200 
201 			value = prescale & PWM_PRESCALE_LOW_MASK;
202 
203 			ret = regmap_field_write(pc->prescale_low, value);
204 			if (ret)
205 				goto clk_dis;
206 
207 			value = (prescale & PWM_PRESCALE_HIGH_MASK) >> 4;
208 
209 			ret = regmap_field_write(pc->prescale_high, value);
210 			if (ret)
211 				goto clk_dis;
212 		}
213 
214 		/*
215 		 * When PWMVal == 0, PWM pulse = 1 local clock cycle.
216 		 * When PWMVal == max_pwm_count,
217 		 * PWM pulse = (max_pwm_count + 1) local cycles,
218 		 * that is continuous pulse: signal never goes low.
219 		 */
220 		value = pc->max_pwm_cnt * duty_ns / period_ns;
221 
222 		ret = regmap_write(pc->regmap, PWM_OUT_VAL(pwm->hwpwm), value);
223 		if (ret)
224 			goto clk_dis;
225 
226 		ret = regmap_field_write(pc->pwm_cpt_int_en, 0);
227 
228 		set_bit(pwm->hwpwm, &pc->configured);
229 		pc->cur = pwm;
230 
231 		dev_dbg(dev, "prescale:%u, period:%i, duty:%i, value:%u\n",
232 			prescale, period_ns, duty_ns, value);
233 	} else {
234 		return -EINVAL;
235 	}
236 
237 clk_dis:
238 	clk_disable(pc->pwm_clk);
239 	clk_disable(pc->cpt_clk);
240 	return ret;
241 }
242 
243 static int sti_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
244 {
245 	struct sti_pwm_chip *pc = to_sti_pwmchip(chip);
246 	struct device *dev = pc->dev;
247 	int ret = 0;
248 
249 	/*
250 	 * Since we have a common enable for all PWM devices, do not enable if
251 	 * already enabled.
252 	 */
253 	mutex_lock(&pc->sti_pwm_lock);
254 
255 	if (!pc->en_count) {
256 		ret = clk_enable(pc->pwm_clk);
257 		if (ret)
258 			goto out;
259 
260 		ret = clk_enable(pc->cpt_clk);
261 		if (ret)
262 			goto out;
263 
264 		ret = regmap_field_write(pc->pwm_out_en, 1);
265 		if (ret) {
266 			dev_err(dev, "failed to enable PWM device %u: %d\n",
267 				pwm->hwpwm, ret);
268 			goto out;
269 		}
270 	}
271 
272 	pc->en_count++;
273 
274 out:
275 	mutex_unlock(&pc->sti_pwm_lock);
276 	return ret;
277 }
278 
279 static void sti_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
280 {
281 	struct sti_pwm_chip *pc = to_sti_pwmchip(chip);
282 
283 	mutex_lock(&pc->sti_pwm_lock);
284 
285 	if (--pc->en_count) {
286 		mutex_unlock(&pc->sti_pwm_lock);
287 		return;
288 	}
289 
290 	regmap_field_write(pc->pwm_out_en, 0);
291 
292 	clk_disable(pc->pwm_clk);
293 	clk_disable(pc->cpt_clk);
294 
295 	mutex_unlock(&pc->sti_pwm_lock);
296 }
297 
298 static void sti_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
299 {
300 	struct sti_pwm_chip *pc = to_sti_pwmchip(chip);
301 
302 	clear_bit(pwm->hwpwm, &pc->configured);
303 }
304 
305 static int sti_pwm_capture(struct pwm_chip *chip, struct pwm_device *pwm,
306 			   struct pwm_capture *result, unsigned long timeout)
307 {
308 	struct sti_pwm_chip *pc = to_sti_pwmchip(chip);
309 	struct sti_cpt_ddata *ddata = &pc->ddata[pwm->hwpwm];
310 	struct device *dev = pc->dev;
311 	unsigned int effective_ticks;
312 	unsigned long long high, low;
313 	int ret;
314 
315 	if (pwm->hwpwm >= pc->cpt_num_devs) {
316 		dev_err(dev, "device %u is not valid\n", pwm->hwpwm);
317 		return -EINVAL;
318 	}
319 
320 	mutex_lock(&ddata->lock);
321 	ddata->index = 0;
322 
323 	/* Prepare capture measurement */
324 	regmap_write(pc->regmap, PWM_CPT_EDGE(pwm->hwpwm), CPT_EDGE_RISING);
325 	regmap_field_write(pc->pwm_cpt_int_en, BIT(pwm->hwpwm));
326 
327 	/* Enable capture */
328 	ret = regmap_field_write(pc->pwm_cpt_en, 1);
329 	if (ret) {
330 		dev_err(dev, "failed to enable PWM capture %u: %d\n",
331 			pwm->hwpwm, ret);
332 		goto out;
333 	}
334 
335 	ret = wait_event_interruptible_timeout(ddata->wait, ddata->index > 1,
336 					       msecs_to_jiffies(timeout));
337 
338 	regmap_write(pc->regmap, PWM_CPT_EDGE(pwm->hwpwm), CPT_EDGE_DISABLED);
339 
340 	if (ret == -ERESTARTSYS)
341 		goto out;
342 
343 	switch (ddata->index) {
344 	case 0:
345 	case 1:
346 		/*
347 		 * Getting here could mean:
348 		 *  - input signal is constant of less than 1 Hz
349 		 *  - there is no input signal at all
350 		 *
351 		 * In such case the frequency is rounded down to 0
352 		 */
353 		result->period = 0;
354 		result->duty_cycle = 0;
355 
356 		break;
357 
358 	case 2:
359 		/* We have everying we need */
360 		high = ddata->snapshot[1] - ddata->snapshot[0];
361 		low = ddata->snapshot[2] - ddata->snapshot[1];
362 
363 		effective_ticks = clk_get_rate(pc->cpt_clk);
364 
365 		result->period = (high + low) * NSEC_PER_SEC;
366 		result->period /= effective_ticks;
367 
368 		result->duty_cycle = high * NSEC_PER_SEC;
369 		result->duty_cycle /= effective_ticks;
370 
371 		break;
372 
373 	default:
374 		dev_err(dev, "internal error\n");
375 		break;
376 	}
377 
378 out:
379 	/* Disable capture */
380 	regmap_field_write(pc->pwm_cpt_en, 0);
381 
382 	mutex_unlock(&ddata->lock);
383 	return ret;
384 }
385 
386 static int sti_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
387 			 const struct pwm_state *state)
388 {
389 	struct sti_pwm_chip *pc = to_sti_pwmchip(chip);
390 	struct device *dev = pc->dev;
391 	int err;
392 
393 	if (pwm->hwpwm >= pc->pwm_num_devs) {
394 		dev_err(dev, "device %u is not valid for pwm mode\n",
395 			pwm->hwpwm);
396 		return -EINVAL;
397 	}
398 
399 	if (state->polarity != PWM_POLARITY_NORMAL)
400 		return -EINVAL;
401 
402 	if (!state->enabled) {
403 		if (pwm->state.enabled)
404 			sti_pwm_disable(chip, pwm);
405 
406 		return 0;
407 	}
408 
409 	err = sti_pwm_config(chip, pwm, state->duty_cycle, state->period);
410 	if (err)
411 		return err;
412 
413 	if (!pwm->state.enabled)
414 		err = sti_pwm_enable(chip, pwm);
415 
416 	return err;
417 }
418 
419 static const struct pwm_ops sti_pwm_ops = {
420 	.capture = sti_pwm_capture,
421 	.apply = sti_pwm_apply,
422 	.free = sti_pwm_free,
423 };
424 
425 static irqreturn_t sti_pwm_interrupt(int irq, void *data)
426 {
427 	struct sti_pwm_chip *pc = data;
428 	struct device *dev = pc->dev;
429 	struct sti_cpt_ddata *ddata;
430 	int devicenum;
431 	unsigned int cpt_int_stat;
432 	unsigned int reg;
433 	int ret = IRQ_NONE;
434 
435 	ret = regmap_field_read(pc->pwm_cpt_int_stat, &cpt_int_stat);
436 	if (ret)
437 		return ret;
438 
439 	while (cpt_int_stat) {
440 		devicenum = ffs(cpt_int_stat) - 1;
441 
442 		ddata = &pc->ddata[devicenum];
443 
444 		/*
445 		 * Capture input:
446 		 *    _______                   _______
447 		 *   |       |                 |       |
448 		 * __|       |_________________|       |________
449 		 *   ^0      ^1                ^2
450 		 *
451 		 * Capture start by the first available rising edge. When a
452 		 * capture event occurs, capture value (CPT_VALx) is stored,
453 		 * index incremented, capture edge changed.
454 		 *
455 		 * After the capture, if the index > 1, we have collected the
456 		 * necessary data so we signal the thread waiting for it and
457 		 * disable the capture by setting capture edge to none
458 		 */
459 
460 		regmap_read(pc->regmap,
461 			    PWM_CPT_VAL(devicenum),
462 			    &ddata->snapshot[ddata->index]);
463 
464 		switch (ddata->index) {
465 		case 0:
466 		case 1:
467 			regmap_read(pc->regmap, PWM_CPT_EDGE(devicenum), &reg);
468 			reg ^= PWM_CPT_EDGE_MASK;
469 			regmap_write(pc->regmap, PWM_CPT_EDGE(devicenum), reg);
470 
471 			ddata->index++;
472 			break;
473 
474 		case 2:
475 			regmap_write(pc->regmap,
476 				     PWM_CPT_EDGE(devicenum),
477 				     CPT_EDGE_DISABLED);
478 			wake_up(&ddata->wait);
479 			break;
480 
481 		default:
482 			dev_err(dev, "Internal error\n");
483 		}
484 
485 		cpt_int_stat &= ~BIT_MASK(devicenum);
486 
487 		ret = IRQ_HANDLED;
488 	}
489 
490 	/* Just ACK everything */
491 	regmap_write(pc->regmap, PWM_INT_ACK, PWM_INT_ACK_MASK);
492 
493 	return ret;
494 }
495 
496 static int sti_pwm_probe_regmap(struct sti_pwm_chip *pc)
497 {
498 	struct device *dev = pc->dev;
499 
500 	pc->prescale_low = devm_regmap_field_alloc(dev, pc->regmap,
501 					sti_pwm_regfields[PWMCLK_PRESCALE_LOW]);
502 	if (IS_ERR(pc->prescale_low))
503 		return PTR_ERR(pc->prescale_low);
504 
505 	pc->prescale_high = devm_regmap_field_alloc(dev, pc->regmap,
506 					sti_pwm_regfields[PWMCLK_PRESCALE_HIGH]);
507 	if (IS_ERR(pc->prescale_high))
508 		return PTR_ERR(pc->prescale_high);
509 
510 	pc->pwm_out_en = devm_regmap_field_alloc(dev, pc->regmap,
511 						 sti_pwm_regfields[PWM_OUT_EN]);
512 	if (IS_ERR(pc->pwm_out_en))
513 		return PTR_ERR(pc->pwm_out_en);
514 
515 	pc->pwm_cpt_en = devm_regmap_field_alloc(dev, pc->regmap,
516 						 sti_pwm_regfields[PWM_CPT_EN]);
517 	if (IS_ERR(pc->pwm_cpt_en))
518 		return PTR_ERR(pc->pwm_cpt_en);
519 
520 	pc->pwm_cpt_int_en = devm_regmap_field_alloc(dev, pc->regmap,
521 						sti_pwm_regfields[PWM_CPT_INT_EN]);
522 	if (IS_ERR(pc->pwm_cpt_int_en))
523 		return PTR_ERR(pc->pwm_cpt_int_en);
524 
525 	pc->pwm_cpt_int_stat = devm_regmap_field_alloc(dev, pc->regmap,
526 						sti_pwm_regfields[PWM_CPT_INT_STAT]);
527 	if (PTR_ERR_OR_ZERO(pc->pwm_cpt_int_stat))
528 		return PTR_ERR(pc->pwm_cpt_int_stat);
529 
530 	return 0;
531 }
532 
533 static const struct regmap_config sti_pwm_regmap_config = {
534 	.reg_bits = 32,
535 	.val_bits = 32,
536 	.reg_stride = 4,
537 };
538 
539 static int sti_pwm_probe(struct platform_device *pdev)
540 {
541 	struct device *dev = &pdev->dev;
542 	struct device_node *np = dev->of_node;
543 	u32 num_devs;
544 	unsigned int pwm_num_devs = 0;
545 	unsigned int cpt_num_devs = 0;
546 	struct pwm_chip *chip;
547 	struct sti_pwm_chip *pc;
548 	unsigned int i;
549 	int irq, ret;
550 
551 	ret = of_property_read_u32(np, "st,pwm-num-chan", &num_devs);
552 	if (!ret)
553 		pwm_num_devs = num_devs;
554 
555 	ret = of_property_read_u32(np, "st,capture-num-chan", &num_devs);
556 	if (!ret)
557 		cpt_num_devs = num_devs;
558 
559 	if (!pwm_num_devs && !cpt_num_devs)
560 		return dev_err_probe(dev, -EINVAL, "No channels configured\n");
561 
562 	chip = devm_pwmchip_alloc(dev, max(pwm_num_devs, cpt_num_devs), sizeof(*pc));
563 	if (IS_ERR(chip))
564 		return PTR_ERR(chip);
565 	pc = to_sti_pwmchip(chip);
566 
567 	pc->mmio = devm_platform_ioremap_resource(pdev, 0);
568 	if (IS_ERR(pc->mmio))
569 		return PTR_ERR(pc->mmio);
570 
571 	pc->regmap = devm_regmap_init_mmio(dev, pc->mmio,
572 					   &sti_pwm_regmap_config);
573 	if (IS_ERR(pc->regmap))
574 		return dev_err_probe(dev, PTR_ERR(pc->regmap),
575 				     "Failed to initialize regmap\n");
576 
577 	irq = platform_get_irq(pdev, 0);
578 	if (irq < 0)
579 		return irq;
580 
581 	ret = devm_request_irq(&pdev->dev, irq, sti_pwm_interrupt, 0,
582 			       pdev->name, pc);
583 	if (ret < 0)
584 		dev_err_probe(&pdev->dev, ret, "Failed to request IRQ\n");
585 
586 	/*
587 	 * Setup PWM data with default values: some values could be replaced
588 	 * with specific ones provided from Device Tree.
589 	 */
590 	pc->max_prescale = 0xff;
591 	pc->max_pwm_cnt = 255;
592 	pc->pwm_num_devs = pwm_num_devs;
593 	pc->cpt_num_devs = cpt_num_devs;
594 
595 	pc->dev = dev;
596 	pc->en_count = 0;
597 	mutex_init(&pc->sti_pwm_lock);
598 
599 	ret = sti_pwm_probe_regmap(pc);
600 	if (ret)
601 		return dev_err_probe(dev, ret, "Failed to initialize regmap fields\n");
602 
603 	if (pwm_num_devs) {
604 		pc->pwm_clk = devm_clk_get_prepared(dev, "pwm");
605 		if (IS_ERR(pc->pwm_clk))
606 			return dev_err_probe(dev, PTR_ERR(pc->pwm_clk),
607 					     "failed to get PWM clock\n");
608 	}
609 
610 	if (cpt_num_devs) {
611 		pc->cpt_clk = devm_clk_get_prepared(dev, "capture");
612 		if (IS_ERR(pc->cpt_clk))
613 			return dev_err_probe(dev, PTR_ERR(pc->cpt_clk),
614 					     "failed to get PWM capture clock\n");
615 
616 		pc->ddata = devm_kcalloc(dev, cpt_num_devs,
617 					 sizeof(*pc->ddata), GFP_KERNEL);
618 		if (!pc->ddata)
619 			return -ENOMEM;
620 
621 		for (i = 0; i < cpt_num_devs; i++) {
622 			struct sti_cpt_ddata *ddata = &pc->ddata[i];
623 
624 			init_waitqueue_head(&ddata->wait);
625 			mutex_init(&ddata->lock);
626 		}
627 	}
628 
629 	chip->ops = &sti_pwm_ops;
630 
631 	ret = devm_pwmchip_add(dev, chip);
632 	if (ret)
633 		return dev_err_probe(dev, ret, "Failed to register pwm chip\n");
634 
635 	return 0;
636 }
637 
638 static const struct of_device_id sti_pwm_of_match[] = {
639 	{ .compatible = "st,sti-pwm", },
640 	{ /* sentinel */ }
641 };
642 MODULE_DEVICE_TABLE(of, sti_pwm_of_match);
643 
644 static struct platform_driver sti_pwm_driver = {
645 	.driver = {
646 		.name = "sti-pwm",
647 		.of_match_table = sti_pwm_of_match,
648 	},
649 	.probe = sti_pwm_probe,
650 };
651 module_platform_driver(sti_pwm_driver);
652 
653 MODULE_AUTHOR("Ajit Pal Singh <ajitpal.singh@st.com>");
654 MODULE_DESCRIPTION("STMicroelectronics ST PWM driver");
655 MODULE_LICENSE("GPL");
656