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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Freescale FlexTimer Module (FTM) PWM Driver
4 *
5 * Copyright 2012-2013 Freescale Semiconductor, Inc.
6 */
7
8#include <linux/clk.h>
9#include <linux/err.h>
10#include <linux/io.h>
11#include <linux/kernel.h>
12#include <linux/module.h>
13#include <linux/mutex.h>
14#include <linux/of_address.h>
15#include <linux/of_device.h>
16#include <linux/platform_device.h>
17#include <linux/pm.h>
18#include <linux/pwm.h>
19#include <linux/regmap.h>
20#include <linux/slab.h>
21#include <linux/fsl/ftm.h>
22
23#define FTM_SC_CLK(c) (((c) + 1) << FTM_SC_CLK_MASK_SHIFT)
24
25enum fsl_pwm_clk {
26 FSL_PWM_CLK_SYS,
27 FSL_PWM_CLK_FIX,
28 FSL_PWM_CLK_EXT,
29 FSL_PWM_CLK_CNTEN,
30 FSL_PWM_CLK_MAX
31};
32
33struct fsl_ftm_soc {
34 bool has_enable_bits;
35};
36
37struct fsl_pwm_periodcfg {
38 enum fsl_pwm_clk clk_select;
39 unsigned int clk_ps;
40 unsigned int mod_period;
41};
42
43struct fsl_pwm_chip {
44 struct pwm_chip chip;
45 struct mutex lock;
46 struct regmap *regmap;
47
48 /* This value is valid iff a pwm is running */
49 struct fsl_pwm_periodcfg period;
50
51 struct clk *ipg_clk;
52 struct clk *clk[FSL_PWM_CLK_MAX];
53
54 const struct fsl_ftm_soc *soc;
55};
56
57static inline struct fsl_pwm_chip *to_fsl_chip(struct pwm_chip *chip)
58{
59 return container_of(chip, struct fsl_pwm_chip, chip);
60}
61
62static void ftm_clear_write_protection(struct fsl_pwm_chip *fpc)
63{
64 u32 val;
65
66 regmap_read(fpc->regmap, FTM_FMS, &val);
67 if (val & FTM_FMS_WPEN)
68 regmap_update_bits(fpc->regmap, FTM_MODE, FTM_MODE_WPDIS,
69 FTM_MODE_WPDIS);
70}
71
72static void ftm_set_write_protection(struct fsl_pwm_chip *fpc)
73{
74 regmap_update_bits(fpc->regmap, FTM_FMS, FTM_FMS_WPEN, FTM_FMS_WPEN);
75}
76
77static bool fsl_pwm_periodcfg_are_equal(const struct fsl_pwm_periodcfg *a,
78 const struct fsl_pwm_periodcfg *b)
79{
80 if (a->clk_select != b->clk_select)
81 return false;
82 if (a->clk_ps != b->clk_ps)
83 return false;
84 if (a->mod_period != b->mod_period)
85 return false;
86 return true;
87}
88
89static int fsl_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
90{
91 int ret;
92 struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
93
94 ret = clk_prepare_enable(fpc->ipg_clk);
95 if (!ret && fpc->soc->has_enable_bits) {
96 mutex_lock(&fpc->lock);
97 regmap_update_bits(fpc->regmap, FTM_SC, BIT(pwm->hwpwm + 16),
98 BIT(pwm->hwpwm + 16));
99 mutex_unlock(&fpc->lock);
100 }
101
102 return ret;
103}
104
105static void fsl_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
106{
107 struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
108
109 if (fpc->soc->has_enable_bits) {
110 mutex_lock(&fpc->lock);
111 regmap_update_bits(fpc->regmap, FTM_SC, BIT(pwm->hwpwm + 16),
112 0);
113 mutex_unlock(&fpc->lock);
114 }
115
116 clk_disable_unprepare(fpc->ipg_clk);
117}
118
119static unsigned int fsl_pwm_ticks_to_ns(struct fsl_pwm_chip *fpc,
120 unsigned int ticks)
121{
122 unsigned long rate;
123 unsigned long long exval;
124
125 rate = clk_get_rate(fpc->clk[fpc->period.clk_select]);
126 exval = ticks;
127 exval *= 1000000000UL;
128 do_div(exval, rate >> fpc->period.clk_ps);
129 return exval;
130}
131
132static bool fsl_pwm_calculate_period_clk(struct fsl_pwm_chip *fpc,
133 unsigned int period_ns,
134 enum fsl_pwm_clk index,
135 struct fsl_pwm_periodcfg *periodcfg
136 )
137{
138 unsigned long long c;
139 unsigned int ps;
140
141 c = clk_get_rate(fpc->clk[index]);
142 c = c * period_ns;
143 do_div(c, 1000000000UL);
144
145 if (c == 0)
146 return false;
147
148 for (ps = 0; ps < 8 ; ++ps, c >>= 1) {
149 if (c <= 0x10000) {
150 periodcfg->clk_select = index;
151 periodcfg->clk_ps = ps;
152 periodcfg->mod_period = c - 1;
153 return true;
154 }
155 }
156 return false;
157}
158
159static bool fsl_pwm_calculate_period(struct fsl_pwm_chip *fpc,
160 unsigned int period_ns,
161 struct fsl_pwm_periodcfg *periodcfg)
162{
163 enum fsl_pwm_clk m0, m1;
164 unsigned long fix_rate, ext_rate;
165 bool ret;
166
167 ret = fsl_pwm_calculate_period_clk(fpc, period_ns, FSL_PWM_CLK_SYS,
168 periodcfg);
169 if (ret)
170 return true;
171
172 fix_rate = clk_get_rate(fpc->clk[FSL_PWM_CLK_FIX]);
173 ext_rate = clk_get_rate(fpc->clk[FSL_PWM_CLK_EXT]);
174
175 if (fix_rate > ext_rate) {
176 m0 = FSL_PWM_CLK_FIX;
177 m1 = FSL_PWM_CLK_EXT;
178 } else {
179 m0 = FSL_PWM_CLK_EXT;
180 m1 = FSL_PWM_CLK_FIX;
181 }
182
183 ret = fsl_pwm_calculate_period_clk(fpc, period_ns, m0, periodcfg);
184 if (ret)
185 return true;
186
187 return fsl_pwm_calculate_period_clk(fpc, period_ns, m1, periodcfg);
188}
189
190static unsigned int fsl_pwm_calculate_duty(struct fsl_pwm_chip *fpc,
191 unsigned int duty_ns)
192{
193 unsigned long long duty;
194
195 unsigned int period = fpc->period.mod_period + 1;
196 unsigned int period_ns = fsl_pwm_ticks_to_ns(fpc, period);
197
198 duty = (unsigned long long)duty_ns * period;
199 do_div(duty, period_ns);
200
201 return (unsigned int)duty;
202}
203
204static bool fsl_pwm_is_any_pwm_enabled(struct fsl_pwm_chip *fpc,
205 struct pwm_device *pwm)
206{
207 u32 val;
208
209 regmap_read(fpc->regmap, FTM_OUTMASK, &val);
210 if (~val & 0xFF)
211 return true;
212 else
213 return false;
214}
215
216static bool fsl_pwm_is_other_pwm_enabled(struct fsl_pwm_chip *fpc,
217 struct pwm_device *pwm)
218{
219 u32 val;
220
221 regmap_read(fpc->regmap, FTM_OUTMASK, &val);
222 if (~(val | BIT(pwm->hwpwm)) & 0xFF)
223 return true;
224 else
225 return false;
226}
227
228static int fsl_pwm_apply_config(struct fsl_pwm_chip *fpc,
229 struct pwm_device *pwm,
230 const struct pwm_state *newstate)
231{
232 unsigned int duty;
233 u32 reg_polarity;
234
235 struct fsl_pwm_periodcfg periodcfg;
236 bool do_write_period = false;
237
238 if (!fsl_pwm_calculate_period(fpc, newstate->period, &periodcfg)) {
239 dev_err(fpc->chip.dev, "failed to calculate new period\n");
240 return -EINVAL;
241 }
242
243 if (!fsl_pwm_is_any_pwm_enabled(fpc, pwm))
244 do_write_period = true;
245 /*
246 * The Freescale FTM controller supports only a single period for
247 * all PWM channels, therefore verify if the newly computed period
248 * is different than the current period being used. In such case
249 * we allow to change the period only if no other pwm is running.
250 */
251 else if (!fsl_pwm_periodcfg_are_equal(&fpc->period, &periodcfg)) {
252 if (fsl_pwm_is_other_pwm_enabled(fpc, pwm)) {
253 dev_err(fpc->chip.dev,
254 "Cannot change period for PWM %u, disable other PWMs first\n",
255 pwm->hwpwm);
256 return -EBUSY;
257 }
258 if (fpc->period.clk_select != periodcfg.clk_select) {
259 int ret;
260 enum fsl_pwm_clk oldclk = fpc->period.clk_select;
261 enum fsl_pwm_clk newclk = periodcfg.clk_select;
262
263 ret = clk_prepare_enable(fpc->clk[newclk]);
264 if (ret)
265 return ret;
266 clk_disable_unprepare(fpc->clk[oldclk]);
267 }
268 do_write_period = true;
269 }
270
271 ftm_clear_write_protection(fpc);
272
273 if (do_write_period) {
274 regmap_update_bits(fpc->regmap, FTM_SC, FTM_SC_CLK_MASK,
275 FTM_SC_CLK(periodcfg.clk_select));
276 regmap_update_bits(fpc->regmap, FTM_SC, FTM_SC_PS_MASK,
277 periodcfg.clk_ps);
278 regmap_write(fpc->regmap, FTM_MOD, periodcfg.mod_period);
279
280 fpc->period = periodcfg;
281 }
282
283 duty = fsl_pwm_calculate_duty(fpc, newstate->duty_cycle);
284
285 regmap_write(fpc->regmap, FTM_CSC(pwm->hwpwm),
286 FTM_CSC_MSB | FTM_CSC_ELSB);
287 regmap_write(fpc->regmap, FTM_CV(pwm->hwpwm), duty);
288
289 reg_polarity = 0;
290 if (newstate->polarity == PWM_POLARITY_INVERSED)
291 reg_polarity = BIT(pwm->hwpwm);
292
293 regmap_update_bits(fpc->regmap, FTM_POL, BIT(pwm->hwpwm), reg_polarity);
294
295 ftm_set_write_protection(fpc);
296
297 return 0;
298}
299
300static int fsl_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
301 const struct pwm_state *newstate)
302{
303 struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
304 struct pwm_state *oldstate = &pwm->state;
305 int ret = 0;
306
307 /*
308 * oldstate to newstate : action
309 *
310 * disabled to disabled : ignore
311 * enabled to disabled : disable
312 * enabled to enabled : update settings
313 * disabled to enabled : update settings + enable
314 */
315
316 mutex_lock(&fpc->lock);
317
318 if (!newstate->enabled) {
319 if (oldstate->enabled) {
320 regmap_update_bits(fpc->regmap, FTM_OUTMASK,
321 BIT(pwm->hwpwm), BIT(pwm->hwpwm));
322 clk_disable_unprepare(fpc->clk[FSL_PWM_CLK_CNTEN]);
323 clk_disable_unprepare(fpc->clk[fpc->period.clk_select]);
324 }
325
326 goto end_mutex;
327 }
328
329 ret = fsl_pwm_apply_config(fpc, pwm, newstate);
330 if (ret)
331 goto end_mutex;
332
333 /* check if need to enable */
334 if (!oldstate->enabled) {
335 ret = clk_prepare_enable(fpc->clk[fpc->period.clk_select]);
336 if (ret)
337 goto end_mutex;
338
339 ret = clk_prepare_enable(fpc->clk[FSL_PWM_CLK_CNTEN]);
340 if (ret) {
341 clk_disable_unprepare(fpc->clk[fpc->period.clk_select]);
342 goto end_mutex;
343 }
344
345 regmap_update_bits(fpc->regmap, FTM_OUTMASK, BIT(pwm->hwpwm),
346 0);
347 }
348
349end_mutex:
350 mutex_unlock(&fpc->lock);
351 return ret;
352}
353
354static const struct pwm_ops fsl_pwm_ops = {
355 .request = fsl_pwm_request,
356 .free = fsl_pwm_free,
357 .apply = fsl_pwm_apply,
358 .owner = THIS_MODULE,
359};
360
361static int fsl_pwm_init(struct fsl_pwm_chip *fpc)
362{
363 int ret;
364
365 ret = clk_prepare_enable(fpc->ipg_clk);
366 if (ret)
367 return ret;
368
369 regmap_write(fpc->regmap, FTM_CNTIN, 0x00);
370 regmap_write(fpc->regmap, FTM_OUTINIT, 0x00);
371 regmap_write(fpc->regmap, FTM_OUTMASK, 0xFF);
372
373 clk_disable_unprepare(fpc->ipg_clk);
374
375 return 0;
376}
377
378static bool fsl_pwm_volatile_reg(struct device *dev, unsigned int reg)
379{
380 switch (reg) {
381 case FTM_FMS:
382 case FTM_MODE:
383 case FTM_CNT:
384 return true;
385 }
386 return false;
387}
388
389static const struct regmap_config fsl_pwm_regmap_config = {
390 .reg_bits = 32,
391 .reg_stride = 4,
392 .val_bits = 32,
393
394 .max_register = FTM_PWMLOAD,
395 .volatile_reg = fsl_pwm_volatile_reg,
396 .cache_type = REGCACHE_FLAT,
397};
398
399static int fsl_pwm_probe(struct platform_device *pdev)
400{
401 struct fsl_pwm_chip *fpc;
402 struct resource *res;
403 void __iomem *base;
404 int ret;
405
406 fpc = devm_kzalloc(&pdev->dev, sizeof(*fpc), GFP_KERNEL);
407 if (!fpc)
408 return -ENOMEM;
409
410 mutex_init(&fpc->lock);
411
412 fpc->soc = of_device_get_match_data(&pdev->dev);
413 fpc->chip.dev = &pdev->dev;
414
415 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
416 base = devm_ioremap_resource(&pdev->dev, res);
417 if (IS_ERR(base))
418 return PTR_ERR(base);
419
420 fpc->regmap = devm_regmap_init_mmio_clk(&pdev->dev, "ftm_sys", base,
421 &fsl_pwm_regmap_config);
422 if (IS_ERR(fpc->regmap)) {
423 dev_err(&pdev->dev, "regmap init failed\n");
424 return PTR_ERR(fpc->regmap);
425 }
426
427 fpc->clk[FSL_PWM_CLK_SYS] = devm_clk_get(&pdev->dev, "ftm_sys");
428 if (IS_ERR(fpc->clk[FSL_PWM_CLK_SYS])) {
429 dev_err(&pdev->dev, "failed to get \"ftm_sys\" clock\n");
430 return PTR_ERR(fpc->clk[FSL_PWM_CLK_SYS]);
431 }
432
433 fpc->clk[FSL_PWM_CLK_FIX] = devm_clk_get(fpc->chip.dev, "ftm_fix");
434 if (IS_ERR(fpc->clk[FSL_PWM_CLK_FIX]))
435 return PTR_ERR(fpc->clk[FSL_PWM_CLK_FIX]);
436
437 fpc->clk[FSL_PWM_CLK_EXT] = devm_clk_get(fpc->chip.dev, "ftm_ext");
438 if (IS_ERR(fpc->clk[FSL_PWM_CLK_EXT]))
439 return PTR_ERR(fpc->clk[FSL_PWM_CLK_EXT]);
440
441 fpc->clk[FSL_PWM_CLK_CNTEN] =
442 devm_clk_get(fpc->chip.dev, "ftm_cnt_clk_en");
443 if (IS_ERR(fpc->clk[FSL_PWM_CLK_CNTEN]))
444 return PTR_ERR(fpc->clk[FSL_PWM_CLK_CNTEN]);
445
446 /*
447 * ipg_clk is the interface clock for the IP. If not provided, use the
448 * ftm_sys clock as the default.
449 */
450 fpc->ipg_clk = devm_clk_get(&pdev->dev, "ipg");
451 if (IS_ERR(fpc->ipg_clk))
452 fpc->ipg_clk = fpc->clk[FSL_PWM_CLK_SYS];
453
454
455 fpc->chip.ops = &fsl_pwm_ops;
456 fpc->chip.of_xlate = of_pwm_xlate_with_flags;
457 fpc->chip.of_pwm_n_cells = 3;
458 fpc->chip.base = -1;
459 fpc->chip.npwm = 8;
460
461 ret = pwmchip_add(&fpc->chip);
462 if (ret < 0) {
463 dev_err(&pdev->dev, "failed to add PWM chip: %d\n", ret);
464 return ret;
465 }
466
467 platform_set_drvdata(pdev, fpc);
468
469 return fsl_pwm_init(fpc);
470}
471
472static int fsl_pwm_remove(struct platform_device *pdev)
473{
474 struct fsl_pwm_chip *fpc = platform_get_drvdata(pdev);
475
476 return pwmchip_remove(&fpc->chip);
477}
478
479#ifdef CONFIG_PM_SLEEP
480static int fsl_pwm_suspend(struct device *dev)
481{
482 struct fsl_pwm_chip *fpc = dev_get_drvdata(dev);
483 int i;
484
485 regcache_cache_only(fpc->regmap, true);
486 regcache_mark_dirty(fpc->regmap);
487
488 for (i = 0; i < fpc->chip.npwm; i++) {
489 struct pwm_device *pwm = &fpc->chip.pwms[i];
490
491 if (!test_bit(PWMF_REQUESTED, &pwm->flags))
492 continue;
493
494 clk_disable_unprepare(fpc->ipg_clk);
495
496 if (!pwm_is_enabled(pwm))
497 continue;
498
499 clk_disable_unprepare(fpc->clk[FSL_PWM_CLK_CNTEN]);
500 clk_disable_unprepare(fpc->clk[fpc->period.clk_select]);
501 }
502
503 return 0;
504}
505
506static int fsl_pwm_resume(struct device *dev)
507{
508 struct fsl_pwm_chip *fpc = dev_get_drvdata(dev);
509 int i;
510
511 for (i = 0; i < fpc->chip.npwm; i++) {
512 struct pwm_device *pwm = &fpc->chip.pwms[i];
513
514 if (!test_bit(PWMF_REQUESTED, &pwm->flags))
515 continue;
516
517 clk_prepare_enable(fpc->ipg_clk);
518
519 if (!pwm_is_enabled(pwm))
520 continue;
521
522 clk_prepare_enable(fpc->clk[fpc->period.clk_select]);
523 clk_prepare_enable(fpc->clk[FSL_PWM_CLK_CNTEN]);
524 }
525
526 /* restore all registers from cache */
527 regcache_cache_only(fpc->regmap, false);
528 regcache_sync(fpc->regmap);
529
530 return 0;
531}
532#endif
533
534static const struct dev_pm_ops fsl_pwm_pm_ops = {
535 SET_SYSTEM_SLEEP_PM_OPS(fsl_pwm_suspend, fsl_pwm_resume)
536};
537
538static const struct fsl_ftm_soc vf610_ftm_pwm = {
539 .has_enable_bits = false,
540};
541
542static const struct fsl_ftm_soc imx8qm_ftm_pwm = {
543 .has_enable_bits = true,
544};
545
546static const struct of_device_id fsl_pwm_dt_ids[] = {
547 { .compatible = "fsl,vf610-ftm-pwm", .data = &vf610_ftm_pwm },
548 { .compatible = "fsl,imx8qm-ftm-pwm", .data = &imx8qm_ftm_pwm },
549 { /* sentinel */ }
550};
551MODULE_DEVICE_TABLE(of, fsl_pwm_dt_ids);
552
553static struct platform_driver fsl_pwm_driver = {
554 .driver = {
555 .name = "fsl-ftm-pwm",
556 .of_match_table = fsl_pwm_dt_ids,
557 .pm = &fsl_pwm_pm_ops,
558 },
559 .probe = fsl_pwm_probe,
560 .remove = fsl_pwm_remove,
561};
562module_platform_driver(fsl_pwm_driver);
563
564MODULE_DESCRIPTION("Freescale FlexTimer Module PWM Driver");
565MODULE_AUTHOR("Xiubo Li <Li.Xiubo@freescale.com>");
566MODULE_ALIAS("platform:fsl-ftm-pwm");
567MODULE_LICENSE("GPL");