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