GNU Linux-libre 4.9.326-gnu1
[releases.git] / drivers / pwm / pwm-sti.c
1 /*
2  * PWM device driver for ST SoCs
3  *
4  * Copyright (C) 2013-2016 STMicroelectronics (R&D) Limited
5  *
6  * Author: Ajit Pal Singh <ajitpal.singh@st.com>
7  *         Lee Jones <lee.jones@linaro.org>
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License as published by
11  * the Free Software Foundation; either version 2 of the License, or
12  * (at your option) any later version.
13  */
14
15 #include <linux/clk.h>
16 #include <linux/interrupt.h>
17 #include <linux/math64.h>
18 #include <linux/mfd/syscon.h>
19 #include <linux/module.h>
20 #include <linux/of.h>
21 #include <linux/platform_device.h>
22 #include <linux/pwm.h>
23 #include <linux/regmap.h>
24 #include <linux/sched.h>
25 #include <linux/slab.h>
26 #include <linux/time.h>
27 #include <linux/wait.h>
28
29 #define PWM_OUT_VAL(x)  (0x00 + (4 * (x))) /* Device's Duty Cycle register */
30 #define PWM_CPT_VAL(x)  (0x10 + (4 * (x))) /* Capture value */
31 #define PWM_CPT_EDGE(x) (0x30 + (4 * (x))) /* Edge to capture on */
32
33 #define STI_PWM_CTRL            0x50    /* Control/Config register */
34 #define STI_INT_EN              0x54    /* Interrupt Enable/Disable register */
35 #define STI_INT_STA             0x58    /* Interrupt Status register */
36 #define PWM_INT_ACK             0x5c
37 #define PWM_PRESCALE_LOW_MASK   0x0f
38 #define PWM_PRESCALE_HIGH_MASK  0xf0
39 #define PWM_CPT_EDGE_MASK       0x03
40 #define PWM_INT_ACK_MASK        0x1ff
41
42 #define STI_MAX_CPT_DEVS        4
43 #define CPT_DC_MAX              0xff
44
45 /* Regfield IDs */
46 enum {
47         /* Bits in PWM_CTRL*/
48         PWMCLK_PRESCALE_LOW,
49         PWMCLK_PRESCALE_HIGH,
50         CPTCLK_PRESCALE,
51
52         PWM_OUT_EN,
53         PWM_CPT_EN,
54
55         PWM_CPT_INT_EN,
56         PWM_CPT_INT_STAT,
57
58         /* Keep last */
59         MAX_REGFIELDS
60 };
61
62 /*
63  * Each capture input can be programmed to detect rising-edge, falling-edge,
64  * either edge or neither egde.
65  */
66 enum sti_cpt_edge {
67         CPT_EDGE_DISABLED,
68         CPT_EDGE_RISING,
69         CPT_EDGE_FALLING,
70         CPT_EDGE_BOTH,
71 };
72
73 struct sti_cpt_ddata {
74         u32 snapshot[3];
75         unsigned int index;
76         struct mutex lock;
77         wait_queue_head_t wait;
78 };
79
80 struct sti_pwm_compat_data {
81         const struct reg_field *reg_fields;
82         unsigned int pwm_num_devs;
83         unsigned int cpt_num_devs;
84         unsigned int max_pwm_cnt;
85         unsigned int max_prescale;
86 };
87
88 struct sti_pwm_chip {
89         struct device *dev;
90         struct clk *pwm_clk;
91         struct clk *cpt_clk;
92         struct regmap *regmap;
93         struct sti_pwm_compat_data *cdata;
94         struct regmap_field *prescale_low;
95         struct regmap_field *prescale_high;
96         struct regmap_field *pwm_out_en;
97         struct regmap_field *pwm_cpt_en;
98         struct regmap_field *pwm_cpt_int_en;
99         struct regmap_field *pwm_cpt_int_stat;
100         struct pwm_chip chip;
101         struct pwm_device *cur;
102         unsigned long configured;
103         unsigned int en_count;
104         struct mutex sti_pwm_lock; /* To sync between enable/disable calls */
105         void __iomem *mmio;
106 };
107
108 static const struct reg_field sti_pwm_regfields[MAX_REGFIELDS] = {
109         [PWMCLK_PRESCALE_LOW] = REG_FIELD(STI_PWM_CTRL, 0, 3),
110         [PWMCLK_PRESCALE_HIGH] = REG_FIELD(STI_PWM_CTRL, 11, 14),
111         [CPTCLK_PRESCALE] = REG_FIELD(STI_PWM_CTRL, 4, 8),
112         [PWM_OUT_EN] = REG_FIELD(STI_PWM_CTRL, 9, 9),
113         [PWM_CPT_EN] = REG_FIELD(STI_PWM_CTRL, 10, 10),
114         [PWM_CPT_INT_EN] = REG_FIELD(STI_INT_EN, 1, 4),
115         [PWM_CPT_INT_STAT] = REG_FIELD(STI_INT_STA, 1, 4),
116 };
117
118 static inline struct sti_pwm_chip *to_sti_pwmchip(struct pwm_chip *chip)
119 {
120         return container_of(chip, struct sti_pwm_chip, chip);
121 }
122
123 /*
124  * Calculate the prescaler value corresponding to the period.
125  */
126 static int sti_pwm_get_prescale(struct sti_pwm_chip *pc, unsigned long period,
127                                 unsigned int *prescale)
128 {
129         struct sti_pwm_compat_data *cdata = pc->cdata;
130         unsigned long clk_rate;
131         unsigned long value;
132         unsigned int ps;
133
134         clk_rate = clk_get_rate(pc->pwm_clk);
135         if (!clk_rate) {
136                 dev_err(pc->dev, "failed to get clock rate\n");
137                 return -EINVAL;
138         }
139
140         /*
141          * prescale = ((period_ns * clk_rate) / (10^9 * (max_pwm_cnt + 1)) - 1
142          */
143         value = NSEC_PER_SEC / clk_rate;
144         value *= cdata->max_pwm_cnt + 1;
145
146         if (period % value)
147                 return -EINVAL;
148
149         ps  = period / value - 1;
150         if (ps > cdata->max_prescale)
151                 return -EINVAL;
152
153         *prescale = ps;
154
155         return 0;
156 }
157
158 /*
159  * For STiH4xx PWM IP, the PWM period is fixed to 256 local clock cycles. The
160  * only way to change the period (apart from changing the PWM input clock) is
161  * to change the PWM clock prescaler.
162  *
163  * The prescaler is of 8 bits, so 256 prescaler values and hence 256 possible
164  * period values are supported (for a particular clock rate). The requested
165  * period will be applied only if it matches one of these 256 values.
166  */
167 static int sti_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
168                           int duty_ns, int period_ns)
169 {
170         struct sti_pwm_chip *pc = to_sti_pwmchip(chip);
171         struct sti_pwm_compat_data *cdata = pc->cdata;
172         unsigned int ncfg, value, prescale = 0;
173         struct pwm_device *cur = pc->cur;
174         struct device *dev = pc->dev;
175         bool period_same = false;
176         int ret;
177
178         ncfg = hweight_long(pc->configured);
179         if (ncfg)
180                 period_same = (period_ns == pwm_get_period(cur));
181
182         /*
183          * Allow configuration changes if one of the following conditions
184          * satisfy.
185          * 1. No devices have been configured.
186          * 2. Only one device has been configured and the new request is for
187          *    the same device.
188          * 3. Only one device has been configured and the new request is for
189          *    a new device and period of the new device is same as the current
190          *    configured period.
191          * 4. More than one devices are configured and period of the new
192          *    requestis the same as the current period.
193          */
194         if (!ncfg ||
195             ((ncfg == 1) && (pwm->hwpwm == cur->hwpwm)) ||
196             ((ncfg == 1) && (pwm->hwpwm != cur->hwpwm) && period_same) ||
197             ((ncfg > 1) && period_same)) {
198                 /* Enable clock before writing to PWM registers. */
199                 ret = clk_enable(pc->pwm_clk);
200                 if (ret)
201                         return ret;
202
203                 ret = clk_enable(pc->cpt_clk);
204                 if (ret)
205                         return ret;
206
207                 if (!period_same) {
208                         ret = sti_pwm_get_prescale(pc, period_ns, &prescale);
209                         if (ret)
210                                 goto clk_dis;
211
212                         value = prescale & PWM_PRESCALE_LOW_MASK;
213
214                         ret = regmap_field_write(pc->prescale_low, value);
215                         if (ret)
216                                 goto clk_dis;
217
218                         value = (prescale & PWM_PRESCALE_HIGH_MASK) >> 4;
219
220                         ret = regmap_field_write(pc->prescale_high, value);
221                         if (ret)
222                                 goto clk_dis;
223                 }
224
225                 /*
226                  * When PWMVal == 0, PWM pulse = 1 local clock cycle.
227                  * When PWMVal == max_pwm_count,
228                  * PWM pulse = (max_pwm_count + 1) local cycles,
229                  * that is continuous pulse: signal never goes low.
230                  */
231                 value = cdata->max_pwm_cnt * duty_ns / period_ns;
232
233                 ret = regmap_write(pc->regmap, PWM_OUT_VAL(pwm->hwpwm), value);
234                 if (ret)
235                         goto clk_dis;
236
237                 ret = regmap_field_write(pc->pwm_cpt_int_en, 0);
238
239                 set_bit(pwm->hwpwm, &pc->configured);
240                 pc->cur = pwm;
241
242                 dev_dbg(dev, "prescale:%u, period:%i, duty:%i, value:%u\n",
243                         prescale, period_ns, duty_ns, value);
244         } else {
245                 return -EINVAL;
246         }
247
248 clk_dis:
249         clk_disable(pc->pwm_clk);
250         clk_disable(pc->cpt_clk);
251         return ret;
252 }
253
254 static int sti_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
255 {
256         struct sti_pwm_chip *pc = to_sti_pwmchip(chip);
257         struct device *dev = pc->dev;
258         int ret = 0;
259
260         /*
261          * Since we have a common enable for all PWM devices, do not enable if
262          * already enabled.
263          */
264         mutex_lock(&pc->sti_pwm_lock);
265
266         if (!pc->en_count) {
267                 ret = clk_enable(pc->pwm_clk);
268                 if (ret)
269                         goto out;
270
271                 ret = clk_enable(pc->cpt_clk);
272                 if (ret)
273                         goto out;
274
275                 ret = regmap_field_write(pc->pwm_out_en, 1);
276                 if (ret) {
277                         dev_err(dev, "failed to enable PWM device %u: %d\n",
278                                 pwm->hwpwm, ret);
279                         goto out;
280                 }
281         }
282
283         pc->en_count++;
284
285 out:
286         mutex_unlock(&pc->sti_pwm_lock);
287         return ret;
288 }
289
290 static void sti_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
291 {
292         struct sti_pwm_chip *pc = to_sti_pwmchip(chip);
293
294         mutex_lock(&pc->sti_pwm_lock);
295
296         if (--pc->en_count) {
297                 mutex_unlock(&pc->sti_pwm_lock);
298                 return;
299         }
300
301         regmap_field_write(pc->pwm_out_en, 0);
302
303         clk_disable(pc->pwm_clk);
304         clk_disable(pc->cpt_clk);
305
306         mutex_unlock(&pc->sti_pwm_lock);
307 }
308
309 static void sti_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
310 {
311         struct sti_pwm_chip *pc = to_sti_pwmchip(chip);
312
313         clear_bit(pwm->hwpwm, &pc->configured);
314 }
315
316 static int sti_pwm_capture(struct pwm_chip *chip, struct pwm_device *pwm,
317                            struct pwm_capture *result, unsigned long timeout)
318 {
319         struct sti_pwm_chip *pc = to_sti_pwmchip(chip);
320         struct sti_pwm_compat_data *cdata = pc->cdata;
321         struct sti_cpt_ddata *ddata = pwm_get_chip_data(pwm);
322         struct device *dev = pc->dev;
323         unsigned int effective_ticks;
324         unsigned long long high, low;
325         int ret;
326
327         if (pwm->hwpwm >= cdata->cpt_num_devs) {
328                 dev_err(dev, "device %u is not valid\n", pwm->hwpwm);
329                 return -EINVAL;
330         }
331
332         mutex_lock(&ddata->lock);
333         ddata->index = 0;
334
335         /* Prepare capture measurement */
336         regmap_write(pc->regmap, PWM_CPT_EDGE(pwm->hwpwm), CPT_EDGE_RISING);
337         regmap_field_write(pc->pwm_cpt_int_en, BIT(pwm->hwpwm));
338
339         /* Enable capture */
340         ret = regmap_field_write(pc->pwm_cpt_en, 1);
341         if (ret) {
342                 dev_err(dev, "failed to enable PWM capture %u: %d\n",
343                         pwm->hwpwm, ret);
344                 goto out;
345         }
346
347         ret = wait_event_interruptible_timeout(ddata->wait, ddata->index > 1,
348                                                msecs_to_jiffies(timeout));
349
350         regmap_write(pc->regmap, PWM_CPT_EDGE(pwm->hwpwm), CPT_EDGE_DISABLED);
351
352         if (ret == -ERESTARTSYS)
353                 goto out;
354
355         switch (ddata->index) {
356         case 0:
357         case 1:
358                 /*
359                  * Getting here could mean:
360                  *  - input signal is constant of less than 1 Hz
361                  *  - there is no input signal at all
362                  *
363                  * In such case the frequency is rounded down to 0
364                  */
365                 result->period = 0;
366                 result->duty_cycle = 0;
367
368                 break;
369
370         case 2:
371                 /* We have everying we need */
372                 high = ddata->snapshot[1] - ddata->snapshot[0];
373                 low = ddata->snapshot[2] - ddata->snapshot[1];
374
375                 effective_ticks = clk_get_rate(pc->cpt_clk);
376
377                 result->period = (high + low) * NSEC_PER_SEC;
378                 result->period /= effective_ticks;
379
380                 result->duty_cycle = high * NSEC_PER_SEC;
381                 result->duty_cycle /= effective_ticks;
382
383                 break;
384
385         default:
386                 dev_err(dev, "internal error\n");
387                 break;
388         }
389
390 out:
391         /* Disable capture */
392         regmap_field_write(pc->pwm_cpt_en, 0);
393
394         mutex_unlock(&ddata->lock);
395         return ret;
396 }
397
398 static const struct pwm_ops sti_pwm_ops = {
399         .capture = sti_pwm_capture,
400         .config = sti_pwm_config,
401         .enable = sti_pwm_enable,
402         .disable = sti_pwm_disable,
403         .free = sti_pwm_free,
404         .owner = THIS_MODULE,
405 };
406
407 static irqreturn_t sti_pwm_interrupt(int irq, void *data)
408 {
409         struct sti_pwm_chip *pc = data;
410         struct device *dev = pc->dev;
411         struct sti_cpt_ddata *ddata;
412         int devicenum;
413         unsigned int cpt_int_stat;
414         unsigned int reg;
415         int ret = IRQ_NONE;
416
417         ret = regmap_field_read(pc->pwm_cpt_int_stat, &cpt_int_stat);
418         if (ret)
419                 return ret;
420
421         while (cpt_int_stat) {
422                 devicenum = ffs(cpt_int_stat) - 1;
423
424                 ddata = pwm_get_chip_data(&pc->chip.pwms[devicenum]);
425
426                 /*
427                  * Capture input:
428                  *    _______                   _______
429                  *   |       |                 |       |
430                  * __|       |_________________|       |________
431                  *   ^0      ^1                ^2
432                  *
433                  * Capture start by the first available rising edge. When a
434                  * capture event occurs, capture value (CPT_VALx) is stored,
435                  * index incremented, capture edge changed.
436                  *
437                  * After the capture, if the index > 1, we have collected the
438                  * necessary data so we signal the thread waiting for it and
439                  * disable the capture by setting capture edge to none
440                  */
441
442                 regmap_read(pc->regmap,
443                             PWM_CPT_VAL(devicenum),
444                             &ddata->snapshot[ddata->index]);
445
446                 switch (ddata->index) {
447                 case 0:
448                 case 1:
449                         regmap_read(pc->regmap, PWM_CPT_EDGE(devicenum), &reg);
450                         reg ^= PWM_CPT_EDGE_MASK;
451                         regmap_write(pc->regmap, PWM_CPT_EDGE(devicenum), reg);
452
453                         ddata->index++;
454                         break;
455
456                 case 2:
457                         regmap_write(pc->regmap,
458                                      PWM_CPT_EDGE(devicenum),
459                                      CPT_EDGE_DISABLED);
460                         wake_up(&ddata->wait);
461                         break;
462
463                 default:
464                         dev_err(dev, "Internal error\n");
465                 }
466
467                 cpt_int_stat &= ~BIT_MASK(devicenum);
468
469                 ret = IRQ_HANDLED;
470         }
471
472         /* Just ACK everything */
473         regmap_write(pc->regmap, PWM_INT_ACK, PWM_INT_ACK_MASK);
474
475         return ret;
476 }
477
478 static int sti_pwm_probe_dt(struct sti_pwm_chip *pc)
479 {
480         struct device *dev = pc->dev;
481         const struct reg_field *reg_fields;
482         struct device_node *np = dev->of_node;
483         struct sti_pwm_compat_data *cdata = pc->cdata;
484         u32 num_devs;
485         int ret;
486
487         ret = of_property_read_u32(np, "st,pwm-num-chan", &num_devs);
488         if (!ret)
489                 cdata->pwm_num_devs = num_devs;
490
491         ret = of_property_read_u32(np, "st,capture-num-chan", &num_devs);
492         if (!ret)
493                 cdata->cpt_num_devs = num_devs;
494
495         if (!cdata->pwm_num_devs && !cdata->cpt_num_devs) {
496                 dev_err(dev, "No channels configured\n");
497                 return -EINVAL;
498         }
499
500         reg_fields = cdata->reg_fields;
501
502         pc->prescale_low = devm_regmap_field_alloc(dev, pc->regmap,
503                                         reg_fields[PWMCLK_PRESCALE_LOW]);
504         if (IS_ERR(pc->prescale_low))
505                 return PTR_ERR(pc->prescale_low);
506
507         pc->prescale_high = devm_regmap_field_alloc(dev, pc->regmap,
508                                         reg_fields[PWMCLK_PRESCALE_HIGH]);
509         if (IS_ERR(pc->prescale_high))
510                 return PTR_ERR(pc->prescale_high);
511
512
513         pc->pwm_out_en = devm_regmap_field_alloc(dev, pc->regmap,
514                                                  reg_fields[PWM_OUT_EN]);
515         if (IS_ERR(pc->pwm_out_en))
516                 return PTR_ERR(pc->pwm_out_en);
517
518         pc->pwm_cpt_en = devm_regmap_field_alloc(dev, pc->regmap,
519                                                  reg_fields[PWM_CPT_EN]);
520         if (IS_ERR(pc->pwm_cpt_en))
521                 return PTR_ERR(pc->pwm_cpt_en);
522
523         pc->pwm_cpt_int_en = devm_regmap_field_alloc(dev, pc->regmap,
524                                                 reg_fields[PWM_CPT_INT_EN]);
525         if (IS_ERR(pc->pwm_cpt_int_en))
526                 return PTR_ERR(pc->pwm_cpt_int_en);
527
528         pc->pwm_cpt_int_stat = devm_regmap_field_alloc(dev, pc->regmap,
529                                                 reg_fields[PWM_CPT_INT_STAT]);
530         if (PTR_ERR_OR_ZERO(pc->pwm_cpt_int_stat))
531                 return PTR_ERR(pc->pwm_cpt_int_stat);
532
533         return 0;
534 }
535
536 static const struct regmap_config sti_pwm_regmap_config = {
537         .reg_bits = 32,
538         .val_bits = 32,
539         .reg_stride = 4,
540 };
541
542 static int sti_pwm_probe(struct platform_device *pdev)
543 {
544         struct device *dev = &pdev->dev;
545         struct sti_pwm_compat_data *cdata;
546         struct sti_pwm_chip *pc;
547         struct resource *res;
548         unsigned int i;
549         int irq, ret;
550
551         pc = devm_kzalloc(dev, sizeof(*pc), GFP_KERNEL);
552         if (!pc)
553                 return -ENOMEM;
554
555         cdata = devm_kzalloc(dev, sizeof(*cdata), GFP_KERNEL);
556         if (!cdata)
557                 return -ENOMEM;
558
559         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
560
561         pc->mmio = devm_ioremap_resource(dev, res);
562         if (IS_ERR(pc->mmio))
563                 return PTR_ERR(pc->mmio);
564
565         pc->regmap = devm_regmap_init_mmio(dev, pc->mmio,
566                                            &sti_pwm_regmap_config);
567         if (IS_ERR(pc->regmap))
568                 return PTR_ERR(pc->regmap);
569
570         irq = platform_get_irq(pdev, 0);
571         if (irq < 0) {
572                 dev_err(&pdev->dev, "Failed to obtain IRQ\n");
573                 return irq;
574         }
575
576         ret = devm_request_irq(&pdev->dev, irq, sti_pwm_interrupt, 0,
577                                pdev->name, pc);
578         if (ret < 0) {
579                 dev_err(&pdev->dev, "Failed to request IRQ\n");
580                 return ret;
581         }
582
583         /*
584          * Setup PWM data with default values: some values could be replaced
585          * with specific ones provided from Device Tree.
586          */
587         cdata->reg_fields = sti_pwm_regfields;
588         cdata->max_prescale = 0xff;
589         cdata->max_pwm_cnt = 255;
590         cdata->pwm_num_devs = 0;
591         cdata->cpt_num_devs = 0;
592
593         pc->cdata = cdata;
594         pc->dev = dev;
595         pc->en_count = 0;
596         mutex_init(&pc->sti_pwm_lock);
597
598         ret = sti_pwm_probe_dt(pc);
599         if (ret)
600                 return ret;
601
602         if (!cdata->pwm_num_devs)
603                 goto skip_pwm;
604
605         pc->pwm_clk = of_clk_get_by_name(dev->of_node, "pwm");
606         if (IS_ERR(pc->pwm_clk)) {
607                 dev_err(dev, "failed to get PWM clock\n");
608                 return PTR_ERR(pc->pwm_clk);
609         }
610
611         ret = clk_prepare(pc->pwm_clk);
612         if (ret) {
613                 dev_err(dev, "failed to prepare clock\n");
614                 return ret;
615         }
616
617 skip_pwm:
618         if (!cdata->cpt_num_devs)
619                 goto skip_cpt;
620
621         pc->cpt_clk = of_clk_get_by_name(dev->of_node, "capture");
622         if (IS_ERR(pc->cpt_clk)) {
623                 dev_err(dev, "failed to get PWM capture clock\n");
624                 return PTR_ERR(pc->cpt_clk);
625         }
626
627         ret = clk_prepare(pc->cpt_clk);
628         if (ret) {
629                 dev_err(dev, "failed to prepare clock\n");
630                 return ret;
631         }
632
633 skip_cpt:
634         pc->chip.dev = dev;
635         pc->chip.ops = &sti_pwm_ops;
636         pc->chip.base = -1;
637         pc->chip.npwm = pc->cdata->pwm_num_devs;
638         pc->chip.can_sleep = true;
639
640         ret = pwmchip_add(&pc->chip);
641         if (ret < 0) {
642                 clk_unprepare(pc->pwm_clk);
643                 clk_unprepare(pc->cpt_clk);
644                 return ret;
645         }
646
647         for (i = 0; i < cdata->cpt_num_devs; i++) {
648                 struct sti_cpt_ddata *ddata;
649
650                 ddata = devm_kzalloc(dev, sizeof(*ddata), GFP_KERNEL);
651                 if (!ddata)
652                         return -ENOMEM;
653
654                 init_waitqueue_head(&ddata->wait);
655                 mutex_init(&ddata->lock);
656
657                 pwm_set_chip_data(&pc->chip.pwms[i], ddata);
658         }
659
660         platform_set_drvdata(pdev, pc);
661
662         return 0;
663 }
664
665 static int sti_pwm_remove(struct platform_device *pdev)
666 {
667         struct sti_pwm_chip *pc = platform_get_drvdata(pdev);
668         unsigned int i;
669
670         for (i = 0; i < pc->cdata->pwm_num_devs; i++)
671                 pwm_disable(&pc->chip.pwms[i]);
672
673         clk_unprepare(pc->pwm_clk);
674         clk_unprepare(pc->cpt_clk);
675
676         return pwmchip_remove(&pc->chip);
677 }
678
679 static const struct of_device_id sti_pwm_of_match[] = {
680         { .compatible = "st,sti-pwm", },
681         { /* sentinel */ }
682 };
683 MODULE_DEVICE_TABLE(of, sti_pwm_of_match);
684
685 static struct platform_driver sti_pwm_driver = {
686         .driver = {
687                 .name = "sti-pwm",
688                 .of_match_table = sti_pwm_of_match,
689         },
690         .probe = sti_pwm_probe,
691         .remove = sti_pwm_remove,
692 };
693 module_platform_driver(sti_pwm_driver);
694
695 MODULE_AUTHOR("Ajit Pal Singh <ajitpal.singh@st.com>");
696 MODULE_DESCRIPTION("STMicroelectronics ST PWM driver");
697 MODULE_LICENSE("GPL");