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1/*
2 * Freescale FlexTimer Module (FTM) PWM Driver
3 *
4 * Copyright 2012-2013 Freescale Semiconductor, Inc.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 */
11
12#include <linux/clk.h>
13#include <linux/err.h>
14#include <linux/io.h>
15#include <linux/kernel.h>
16#include <linux/module.h>
17#include <linux/mutex.h>
18#include <linux/of_address.h>
19#include <linux/platform_device.h>
20#include <linux/pm.h>
21#include <linux/pwm.h>
22#include <linux/regmap.h>
23#include <linux/slab.h>
24
25#define FTM_SC 0x00
26#define FTM_SC_CLK_MASK_SHIFT 3
27#define FTM_SC_CLK_MASK (3 << FTM_SC_CLK_MASK_SHIFT)
28#define FTM_SC_CLK(c) (((c) + 1) << FTM_SC_CLK_MASK_SHIFT)
29#define FTM_SC_PS_MASK 0x7
30
31#define FTM_CNT 0x04
32#define FTM_MOD 0x08
33
34#define FTM_CSC_BASE 0x0C
35#define FTM_CSC_MSB BIT(5)
36#define FTM_CSC_MSA BIT(4)
37#define FTM_CSC_ELSB BIT(3)
38#define FTM_CSC_ELSA BIT(2)
39#define FTM_CSC(_channel) (FTM_CSC_BASE + ((_channel) * 8))
40
41#define FTM_CV_BASE 0x10
42#define FTM_CV(_channel) (FTM_CV_BASE + ((_channel) * 8))
43
44#define FTM_CNTIN 0x4C
45#define FTM_STATUS 0x50
46
47#define FTM_MODE 0x54
48#define FTM_MODE_FTMEN BIT(0)
49#define FTM_MODE_INIT BIT(2)
50#define FTM_MODE_PWMSYNC BIT(3)
51
52#define FTM_SYNC 0x58
53#define FTM_OUTINIT 0x5C
54#define FTM_OUTMASK 0x60
55#define FTM_COMBINE 0x64
56#define FTM_DEADTIME 0x68
57#define FTM_EXTTRIG 0x6C
58#define FTM_POL 0x70
59#define FTM_FMS 0x74
60#define FTM_FILTER 0x78
61#define FTM_FLTCTRL 0x7C
62#define FTM_QDCTRL 0x80
63#define FTM_CONF 0x84
64#define FTM_FLTPOL 0x88
65#define FTM_SYNCONF 0x8C
66#define FTM_INVCTRL 0x90
67#define FTM_SWOCTRL 0x94
68#define FTM_PWMLOAD 0x98
69
70enum fsl_pwm_clk {
71 FSL_PWM_CLK_SYS,
72 FSL_PWM_CLK_FIX,
73 FSL_PWM_CLK_EXT,
74 FSL_PWM_CLK_CNTEN,
75 FSL_PWM_CLK_MAX
76};
77
78struct fsl_pwm_chip {
79 struct pwm_chip chip;
80
81 struct mutex lock;
82
83 unsigned int cnt_select;
84 unsigned int clk_ps;
85
86 struct regmap *regmap;
87
88 int period_ns;
89
90 struct clk *clk[FSL_PWM_CLK_MAX];
91};
92
93static inline struct fsl_pwm_chip *to_fsl_chip(struct pwm_chip *chip)
94{
95 return container_of(chip, struct fsl_pwm_chip, chip);
96}
97
98static int fsl_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
99{
100 struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
101
102 return clk_prepare_enable(fpc->clk[FSL_PWM_CLK_SYS]);
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 clk_disable_unprepare(fpc->clk[FSL_PWM_CLK_SYS]);
110}
111
112static int fsl_pwm_calculate_default_ps(struct fsl_pwm_chip *fpc,
113 enum fsl_pwm_clk index)
114{
115 unsigned long sys_rate, cnt_rate;
116 unsigned long long ratio;
117
118 sys_rate = clk_get_rate(fpc->clk[FSL_PWM_CLK_SYS]);
119 if (!sys_rate)
120 return -EINVAL;
121
122 cnt_rate = clk_get_rate(fpc->clk[fpc->cnt_select]);
123 if (!cnt_rate)
124 return -EINVAL;
125
126 switch (index) {
127 case FSL_PWM_CLK_SYS:
128 fpc->clk_ps = 1;
129 break;
130 case FSL_PWM_CLK_FIX:
131 ratio = 2 * cnt_rate - 1;
132 do_div(ratio, sys_rate);
133 fpc->clk_ps = ratio;
134 break;
135 case FSL_PWM_CLK_EXT:
136 ratio = 4 * cnt_rate - 1;
137 do_div(ratio, sys_rate);
138 fpc->clk_ps = ratio;
139 break;
140 default:
141 return -EINVAL;
142 }
143
144 return 0;
145}
146
147static unsigned long fsl_pwm_calculate_cycles(struct fsl_pwm_chip *fpc,
148 unsigned long period_ns)
149{
150 unsigned long long c, c0;
151
152 c = clk_get_rate(fpc->clk[fpc->cnt_select]);
153 c = c * period_ns;
154 do_div(c, 1000000000UL);
155
156 do {
157 c0 = c;
158 do_div(c0, (1 << fpc->clk_ps));
159 if (c0 <= 0xFFFF)
160 return (unsigned long)c0;
161 } while (++fpc->clk_ps < 8);
162
163 return 0;
164}
165
166static unsigned long fsl_pwm_calculate_period_cycles(struct fsl_pwm_chip *fpc,
167 unsigned long period_ns,
168 enum fsl_pwm_clk index)
169{
170 int ret;
171
172 ret = fsl_pwm_calculate_default_ps(fpc, index);
173 if (ret) {
174 dev_err(fpc->chip.dev,
175 "failed to calculate default prescaler: %d\n",
176 ret);
177 return 0;
178 }
179
180 return fsl_pwm_calculate_cycles(fpc, period_ns);
181}
182
183static unsigned long fsl_pwm_calculate_period(struct fsl_pwm_chip *fpc,
184 unsigned long period_ns)
185{
186 enum fsl_pwm_clk m0, m1;
187 unsigned long fix_rate, ext_rate, cycles;
188
189 cycles = fsl_pwm_calculate_period_cycles(fpc, period_ns,
190 FSL_PWM_CLK_SYS);
191 if (cycles) {
192 fpc->cnt_select = FSL_PWM_CLK_SYS;
193 return cycles;
194 }
195
196 fix_rate = clk_get_rate(fpc->clk[FSL_PWM_CLK_FIX]);
197 ext_rate = clk_get_rate(fpc->clk[FSL_PWM_CLK_EXT]);
198
199 if (fix_rate > ext_rate) {
200 m0 = FSL_PWM_CLK_FIX;
201 m1 = FSL_PWM_CLK_EXT;
202 } else {
203 m0 = FSL_PWM_CLK_EXT;
204 m1 = FSL_PWM_CLK_FIX;
205 }
206
207 cycles = fsl_pwm_calculate_period_cycles(fpc, period_ns, m0);
208 if (cycles) {
209 fpc->cnt_select = m0;
210 return cycles;
211 }
212
213 fpc->cnt_select = m1;
214
215 return fsl_pwm_calculate_period_cycles(fpc, period_ns, m1);
216}
217
218static unsigned long fsl_pwm_calculate_duty(struct fsl_pwm_chip *fpc,
219 unsigned long period_ns,
220 unsigned long duty_ns)
221{
222 unsigned long long duty;
223 u32 val;
224
225 regmap_read(fpc->regmap, FTM_MOD, &val);
226 duty = (unsigned long long)duty_ns * (val + 1);
227 do_div(duty, period_ns);
228
229 return (unsigned long)duty;
230}
231
232static int fsl_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
233 int duty_ns, int period_ns)
234{
235 struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
236 u32 period, duty;
237
238 mutex_lock(&fpc->lock);
239
240 /*
241 * The Freescale FTM controller supports only a single period for
242 * all PWM channels, therefore incompatible changes need to be
243 * refused.
244 */
245 if (fpc->period_ns && fpc->period_ns != period_ns) {
246 dev_err(fpc->chip.dev,
247 "conflicting period requested for PWM %u\n",
248 pwm->hwpwm);
249 mutex_unlock(&fpc->lock);
250 return -EBUSY;
251 }
252
253 if (!fpc->period_ns && duty_ns) {
254 period = fsl_pwm_calculate_period(fpc, period_ns);
255 if (!period) {
256 dev_err(fpc->chip.dev, "failed to calculate period\n");
257 mutex_unlock(&fpc->lock);
258 return -EINVAL;
259 }
260
261 regmap_update_bits(fpc->regmap, FTM_SC, FTM_SC_PS_MASK,
262 fpc->clk_ps);
263 regmap_write(fpc->regmap, FTM_MOD, period - 1);
264
265 fpc->period_ns = period_ns;
266 }
267
268 mutex_unlock(&fpc->lock);
269
270 duty = fsl_pwm_calculate_duty(fpc, period_ns, duty_ns);
271
272 regmap_write(fpc->regmap, FTM_CSC(pwm->hwpwm),
273 FTM_CSC_MSB | FTM_CSC_ELSB);
274 regmap_write(fpc->regmap, FTM_CV(pwm->hwpwm), duty);
275
276 return 0;
277}
278
279static int fsl_pwm_set_polarity(struct pwm_chip *chip,
280 struct pwm_device *pwm,
281 enum pwm_polarity polarity)
282{
283 struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
284 u32 val;
285
286 regmap_read(fpc->regmap, FTM_POL, &val);
287
288 if (polarity == PWM_POLARITY_INVERSED)
289 val |= BIT(pwm->hwpwm);
290 else
291 val &= ~BIT(pwm->hwpwm);
292
293 regmap_write(fpc->regmap, FTM_POL, val);
294
295 return 0;
296}
297
298static int fsl_counter_clock_enable(struct fsl_pwm_chip *fpc)
299{
300 int ret;
301
302 /* select counter clock source */
303 regmap_update_bits(fpc->regmap, FTM_SC, FTM_SC_CLK_MASK,
304 FTM_SC_CLK(fpc->cnt_select));
305
306 ret = clk_prepare_enable(fpc->clk[fpc->cnt_select]);
307 if (ret)
308 return ret;
309
310 ret = clk_prepare_enable(fpc->clk[FSL_PWM_CLK_CNTEN]);
311 if (ret) {
312 clk_disable_unprepare(fpc->clk[fpc->cnt_select]);
313 return ret;
314 }
315
316 return 0;
317}
318
319static int fsl_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
320{
321 struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
322 int ret;
323
324 mutex_lock(&fpc->lock);
325 regmap_update_bits(fpc->regmap, FTM_OUTMASK, BIT(pwm->hwpwm), 0);
326
327 ret = fsl_counter_clock_enable(fpc);
328 mutex_unlock(&fpc->lock);
329
330 return ret;
331}
332
333static void fsl_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
334{
335 struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
336 u32 val;
337
338 mutex_lock(&fpc->lock);
339 regmap_update_bits(fpc->regmap, FTM_OUTMASK, BIT(pwm->hwpwm),
340 BIT(pwm->hwpwm));
341
342 clk_disable_unprepare(fpc->clk[FSL_PWM_CLK_CNTEN]);
343 clk_disable_unprepare(fpc->clk[fpc->cnt_select]);
344
345 regmap_read(fpc->regmap, FTM_OUTMASK, &val);
346 if ((val & 0xFF) == 0xFF)
347 fpc->period_ns = 0;
348
349 mutex_unlock(&fpc->lock);
350}
351
352static const struct pwm_ops fsl_pwm_ops = {
353 .request = fsl_pwm_request,
354 .free = fsl_pwm_free,
355 .config = fsl_pwm_config,
356 .set_polarity = fsl_pwm_set_polarity,
357 .enable = fsl_pwm_enable,
358 .disable = fsl_pwm_disable,
359 .owner = THIS_MODULE,
360};
361
362static int fsl_pwm_init(struct fsl_pwm_chip *fpc)
363{
364 int ret;
365
366 ret = clk_prepare_enable(fpc->clk[FSL_PWM_CLK_SYS]);
367 if (ret)
368 return ret;
369
370 regmap_write(fpc->regmap, FTM_CNTIN, 0x00);
371 regmap_write(fpc->regmap, FTM_OUTINIT, 0x00);
372 regmap_write(fpc->regmap, FTM_OUTMASK, 0xFF);
373
374 clk_disable_unprepare(fpc->clk[FSL_PWM_CLK_SYS]);
375
376 return 0;
377}
378
379static bool fsl_pwm_volatile_reg(struct device *dev, unsigned int reg)
380{
381 switch (reg) {
382 case FTM_CNT:
383 return true;
384 }
385 return false;
386}
387
388static const struct regmap_config fsl_pwm_regmap_config = {
389 .reg_bits = 32,
390 .reg_stride = 4,
391 .val_bits = 32,
392
393 .max_register = FTM_PWMLOAD,
394 .volatile_reg = fsl_pwm_volatile_reg,
395 .cache_type = REGCACHE_FLAT,
396};
397
398static int fsl_pwm_probe(struct platform_device *pdev)
399{
400 struct fsl_pwm_chip *fpc;
401 struct resource *res;
402 void __iomem *base;
403 int ret;
404
405 fpc = devm_kzalloc(&pdev->dev, sizeof(*fpc), GFP_KERNEL);
406 if (!fpc)
407 return -ENOMEM;
408
409 mutex_init(&fpc->lock);
410
411 fpc->chip.dev = &pdev->dev;
412
413 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
414 base = devm_ioremap_resource(&pdev->dev, res);
415 if (IS_ERR(base))
416 return PTR_ERR(base);
417
418 fpc->regmap = devm_regmap_init_mmio_clk(&pdev->dev, "ftm_sys", base,
419 &fsl_pwm_regmap_config);
420 if (IS_ERR(fpc->regmap)) {
421 dev_err(&pdev->dev, "regmap init failed\n");
422 return PTR_ERR(fpc->regmap);
423 }
424
425 fpc->clk[FSL_PWM_CLK_SYS] = devm_clk_get(&pdev->dev, "ftm_sys");
426 if (IS_ERR(fpc->clk[FSL_PWM_CLK_SYS])) {
427 dev_err(&pdev->dev, "failed to get \"ftm_sys\" clock\n");
428 return PTR_ERR(fpc->clk[FSL_PWM_CLK_SYS]);
429 }
430
431 fpc->clk[FSL_PWM_CLK_FIX] = devm_clk_get(fpc->chip.dev, "ftm_fix");
432 if (IS_ERR(fpc->clk[FSL_PWM_CLK_FIX]))
433 return PTR_ERR(fpc->clk[FSL_PWM_CLK_FIX]);
434
435 fpc->clk[FSL_PWM_CLK_EXT] = devm_clk_get(fpc->chip.dev, "ftm_ext");
436 if (IS_ERR(fpc->clk[FSL_PWM_CLK_EXT]))
437 return PTR_ERR(fpc->clk[FSL_PWM_CLK_EXT]);
438
439 fpc->clk[FSL_PWM_CLK_CNTEN] =
440 devm_clk_get(fpc->chip.dev, "ftm_cnt_clk_en");
441 if (IS_ERR(fpc->clk[FSL_PWM_CLK_CNTEN]))
442 return PTR_ERR(fpc->clk[FSL_PWM_CLK_CNTEN]);
443
444 fpc->chip.ops = &fsl_pwm_ops;
445 fpc->chip.of_xlate = of_pwm_xlate_with_flags;
446 fpc->chip.of_pwm_n_cells = 3;
447 fpc->chip.base = -1;
448 fpc->chip.npwm = 8;
449 fpc->chip.can_sleep = true;
450
451 ret = pwmchip_add(&fpc->chip);
452 if (ret < 0) {
453 dev_err(&pdev->dev, "failed to add PWM chip: %d\n", ret);
454 return ret;
455 }
456
457 platform_set_drvdata(pdev, fpc);
458
459 return fsl_pwm_init(fpc);
460}
461
462static int fsl_pwm_remove(struct platform_device *pdev)
463{
464 struct fsl_pwm_chip *fpc = platform_get_drvdata(pdev);
465
466 return pwmchip_remove(&fpc->chip);
467}
468
469#ifdef CONFIG_PM_SLEEP
470static int fsl_pwm_suspend(struct device *dev)
471{
472 struct fsl_pwm_chip *fpc = dev_get_drvdata(dev);
473 int i;
474
475 regcache_cache_only(fpc->regmap, true);
476 regcache_mark_dirty(fpc->regmap);
477
478 for (i = 0; i < fpc->chip.npwm; i++) {
479 struct pwm_device *pwm = &fpc->chip.pwms[i];
480
481 if (!test_bit(PWMF_REQUESTED, &pwm->flags))
482 continue;
483
484 clk_disable_unprepare(fpc->clk[FSL_PWM_CLK_SYS]);
485
486 if (!pwm_is_enabled(pwm))
487 continue;
488
489 clk_disable_unprepare(fpc->clk[FSL_PWM_CLK_CNTEN]);
490 clk_disable_unprepare(fpc->clk[fpc->cnt_select]);
491 }
492
493 return 0;
494}
495
496static int fsl_pwm_resume(struct device *dev)
497{
498 struct fsl_pwm_chip *fpc = dev_get_drvdata(dev);
499 int i;
500
501 for (i = 0; i < fpc->chip.npwm; i++) {
502 struct pwm_device *pwm = &fpc->chip.pwms[i];
503
504 if (!test_bit(PWMF_REQUESTED, &pwm->flags))
505 continue;
506
507 clk_prepare_enable(fpc->clk[FSL_PWM_CLK_SYS]);
508
509 if (!pwm_is_enabled(pwm))
510 continue;
511
512 clk_prepare_enable(fpc->clk[fpc->cnt_select]);
513 clk_prepare_enable(fpc->clk[FSL_PWM_CLK_CNTEN]);
514 }
515
516 /* restore all registers from cache */
517 regcache_cache_only(fpc->regmap, false);
518 regcache_sync(fpc->regmap);
519
520 return 0;
521}
522#endif
523
524static const struct dev_pm_ops fsl_pwm_pm_ops = {
525 SET_SYSTEM_SLEEP_PM_OPS(fsl_pwm_suspend, fsl_pwm_resume)
526};
527
528static const struct of_device_id fsl_pwm_dt_ids[] = {
529 { .compatible = "fsl,vf610-ftm-pwm", },
530 { /* sentinel */ }
531};
532MODULE_DEVICE_TABLE(of, fsl_pwm_dt_ids);
533
534static struct platform_driver fsl_pwm_driver = {
535 .driver = {
536 .name = "fsl-ftm-pwm",
537 .of_match_table = fsl_pwm_dt_ids,
538 .pm = &fsl_pwm_pm_ops,
539 },
540 .probe = fsl_pwm_probe,
541 .remove = fsl_pwm_remove,
542};
543module_platform_driver(fsl_pwm_driver);
544
545MODULE_DESCRIPTION("Freescale FlexTimer Module PWM Driver");
546MODULE_AUTHOR("Xiubo Li <Li.Xiubo@freescale.com>");
547MODULE_ALIAS("platform:fsl-ftm-pwm");
548MODULE_LICENSE("GPL");