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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * EHRPWM PWM driver
4 *
5 * Copyright (C) 2012 Texas Instruments, Inc. - https://www.ti.com/
6 */
7
8#include <linux/module.h>
9#include <linux/platform_device.h>
10#include <linux/pwm.h>
11#include <linux/io.h>
12#include <linux/err.h>
13#include <linux/clk.h>
14#include <linux/pm_runtime.h>
15#include <linux/of_device.h>
16
17/* EHRPWM registers and bits definitions */
18
19/* Time base module registers */
20#define TBCTL 0x00
21#define TBPRD 0x0A
22
23#define TBCTL_PRDLD_MASK BIT(3)
24#define TBCTL_PRDLD_SHDW 0
25#define TBCTL_PRDLD_IMDT BIT(3)
26#define TBCTL_CLKDIV_MASK (BIT(12) | BIT(11) | BIT(10) | BIT(9) | \
27 BIT(8) | BIT(7))
28#define TBCTL_CTRMODE_MASK (BIT(1) | BIT(0))
29#define TBCTL_CTRMODE_UP 0
30#define TBCTL_CTRMODE_DOWN BIT(0)
31#define TBCTL_CTRMODE_UPDOWN BIT(1)
32#define TBCTL_CTRMODE_FREEZE (BIT(1) | BIT(0))
33
34#define TBCTL_HSPCLKDIV_SHIFT 7
35#define TBCTL_CLKDIV_SHIFT 10
36
37#define CLKDIV_MAX 7
38#define HSPCLKDIV_MAX 7
39#define PERIOD_MAX 0xFFFF
40
41/* compare module registers */
42#define CMPA 0x12
43#define CMPB 0x14
44
45/* Action qualifier module registers */
46#define AQCTLA 0x16
47#define AQCTLB 0x18
48#define AQSFRC 0x1A
49#define AQCSFRC 0x1C
50
51#define AQCTL_CBU_MASK (BIT(9) | BIT(8))
52#define AQCTL_CBU_FRCLOW BIT(8)
53#define AQCTL_CBU_FRCHIGH BIT(9)
54#define AQCTL_CBU_FRCTOGGLE (BIT(9) | BIT(8))
55#define AQCTL_CAU_MASK (BIT(5) | BIT(4))
56#define AQCTL_CAU_FRCLOW BIT(4)
57#define AQCTL_CAU_FRCHIGH BIT(5)
58#define AQCTL_CAU_FRCTOGGLE (BIT(5) | BIT(4))
59#define AQCTL_PRD_MASK (BIT(3) | BIT(2))
60#define AQCTL_PRD_FRCLOW BIT(2)
61#define AQCTL_PRD_FRCHIGH BIT(3)
62#define AQCTL_PRD_FRCTOGGLE (BIT(3) | BIT(2))
63#define AQCTL_ZRO_MASK (BIT(1) | BIT(0))
64#define AQCTL_ZRO_FRCLOW BIT(0)
65#define AQCTL_ZRO_FRCHIGH BIT(1)
66#define AQCTL_ZRO_FRCTOGGLE (BIT(1) | BIT(0))
67
68#define AQCTL_CHANA_POLNORMAL (AQCTL_CAU_FRCLOW | AQCTL_PRD_FRCHIGH | \
69 AQCTL_ZRO_FRCHIGH)
70#define AQCTL_CHANA_POLINVERSED (AQCTL_CAU_FRCHIGH | AQCTL_PRD_FRCLOW | \
71 AQCTL_ZRO_FRCLOW)
72#define AQCTL_CHANB_POLNORMAL (AQCTL_CBU_FRCLOW | AQCTL_PRD_FRCHIGH | \
73 AQCTL_ZRO_FRCHIGH)
74#define AQCTL_CHANB_POLINVERSED (AQCTL_CBU_FRCHIGH | AQCTL_PRD_FRCLOW | \
75 AQCTL_ZRO_FRCLOW)
76
77#define AQSFRC_RLDCSF_MASK (BIT(7) | BIT(6))
78#define AQSFRC_RLDCSF_ZRO 0
79#define AQSFRC_RLDCSF_PRD BIT(6)
80#define AQSFRC_RLDCSF_ZROPRD BIT(7)
81#define AQSFRC_RLDCSF_IMDT (BIT(7) | BIT(6))
82
83#define AQCSFRC_CSFB_MASK (BIT(3) | BIT(2))
84#define AQCSFRC_CSFB_FRCDIS 0
85#define AQCSFRC_CSFB_FRCLOW BIT(2)
86#define AQCSFRC_CSFB_FRCHIGH BIT(3)
87#define AQCSFRC_CSFB_DISSWFRC (BIT(3) | BIT(2))
88#define AQCSFRC_CSFA_MASK (BIT(1) | BIT(0))
89#define AQCSFRC_CSFA_FRCDIS 0
90#define AQCSFRC_CSFA_FRCLOW BIT(0)
91#define AQCSFRC_CSFA_FRCHIGH BIT(1)
92#define AQCSFRC_CSFA_DISSWFRC (BIT(1) | BIT(0))
93
94#define NUM_PWM_CHANNEL 2 /* EHRPWM channels */
95
96struct ehrpwm_context {
97 u16 tbctl;
98 u16 tbprd;
99 u16 cmpa;
100 u16 cmpb;
101 u16 aqctla;
102 u16 aqctlb;
103 u16 aqsfrc;
104 u16 aqcsfrc;
105};
106
107struct ehrpwm_pwm_chip {
108 struct pwm_chip chip;
109 unsigned long clk_rate;
110 void __iomem *mmio_base;
111 unsigned long period_cycles[NUM_PWM_CHANNEL];
112 enum pwm_polarity polarity[NUM_PWM_CHANNEL];
113 struct clk *tbclk;
114 struct ehrpwm_context ctx;
115};
116
117static inline struct ehrpwm_pwm_chip *to_ehrpwm_pwm_chip(struct pwm_chip *chip)
118{
119 return container_of(chip, struct ehrpwm_pwm_chip, chip);
120}
121
122static inline u16 ehrpwm_read(void __iomem *base, unsigned int offset)
123{
124 return readw(base + offset);
125}
126
127static inline void ehrpwm_write(void __iomem *base, unsigned int offset,
128 u16 value)
129{
130 writew(value, base + offset);
131}
132
133static void ehrpwm_modify(void __iomem *base, unsigned int offset, u16 mask,
134 u16 value)
135{
136 unsigned short val;
137
138 val = readw(base + offset);
139 val &= ~mask;
140 val |= value & mask;
141 writew(val, base + offset);
142}
143
144/**
145 * set_prescale_div - Set up the prescaler divider function
146 * @rqst_prescaler: prescaler value min
147 * @prescale_div: prescaler value set
148 * @tb_clk_div: Time Base Control prescaler bits
149 */
150static int set_prescale_div(unsigned long rqst_prescaler, u16 *prescale_div,
151 u16 *tb_clk_div)
152{
153 unsigned int clkdiv, hspclkdiv;
154
155 for (clkdiv = 0; clkdiv <= CLKDIV_MAX; clkdiv++) {
156 for (hspclkdiv = 0; hspclkdiv <= HSPCLKDIV_MAX; hspclkdiv++) {
157 /*
158 * calculations for prescaler value :
159 * prescale_div = HSPCLKDIVIDER * CLKDIVIDER.
160 * HSPCLKDIVIDER = 2 ** hspclkdiv
161 * CLKDIVIDER = (1), if clkdiv == 0 *OR*
162 * (2 * clkdiv), if clkdiv != 0
163 *
164 * Configure prescale_div value such that period
165 * register value is less than 65535.
166 */
167
168 *prescale_div = (1 << clkdiv) *
169 (hspclkdiv ? (hspclkdiv * 2) : 1);
170 if (*prescale_div > rqst_prescaler) {
171 *tb_clk_div = (clkdiv << TBCTL_CLKDIV_SHIFT) |
172 (hspclkdiv << TBCTL_HSPCLKDIV_SHIFT);
173 return 0;
174 }
175 }
176 }
177
178 return 1;
179}
180
181static void configure_polarity(struct ehrpwm_pwm_chip *pc, int chan)
182{
183 u16 aqctl_val, aqctl_mask;
184 unsigned int aqctl_reg;
185
186 /*
187 * Configure PWM output to HIGH/LOW level on counter
188 * reaches compare register value and LOW/HIGH level
189 * on counter value reaches period register value and
190 * zero value on counter
191 */
192 if (chan == 1) {
193 aqctl_reg = AQCTLB;
194 aqctl_mask = AQCTL_CBU_MASK;
195
196 if (pc->polarity[chan] == PWM_POLARITY_INVERSED)
197 aqctl_val = AQCTL_CHANB_POLINVERSED;
198 else
199 aqctl_val = AQCTL_CHANB_POLNORMAL;
200 } else {
201 aqctl_reg = AQCTLA;
202 aqctl_mask = AQCTL_CAU_MASK;
203
204 if (pc->polarity[chan] == PWM_POLARITY_INVERSED)
205 aqctl_val = AQCTL_CHANA_POLINVERSED;
206 else
207 aqctl_val = AQCTL_CHANA_POLNORMAL;
208 }
209
210 aqctl_mask |= AQCTL_PRD_MASK | AQCTL_ZRO_MASK;
211 ehrpwm_modify(pc->mmio_base, aqctl_reg, aqctl_mask, aqctl_val);
212}
213
214/*
215 * period_ns = 10^9 * (ps_divval * period_cycles) / PWM_CLK_RATE
216 * duty_ns = 10^9 * (ps_divval * duty_cycles) / PWM_CLK_RATE
217 */
218static int ehrpwm_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
219 int duty_ns, int period_ns)
220{
221 struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
222 u32 period_cycles, duty_cycles;
223 u16 ps_divval, tb_divval;
224 unsigned int i, cmp_reg;
225 unsigned long long c;
226
227 if (period_ns > NSEC_PER_SEC)
228 return -ERANGE;
229
230 c = pc->clk_rate;
231 c = c * period_ns;
232 do_div(c, NSEC_PER_SEC);
233 period_cycles = (unsigned long)c;
234
235 if (period_cycles < 1) {
236 period_cycles = 1;
237 duty_cycles = 1;
238 } else {
239 c = pc->clk_rate;
240 c = c * duty_ns;
241 do_div(c, NSEC_PER_SEC);
242 duty_cycles = (unsigned long)c;
243 }
244
245 /*
246 * Period values should be same for multiple PWM channels as IP uses
247 * same period register for multiple channels.
248 */
249 for (i = 0; i < NUM_PWM_CHANNEL; i++) {
250 if (pc->period_cycles[i] &&
251 (pc->period_cycles[i] != period_cycles)) {
252 /*
253 * Allow channel to reconfigure period if no other
254 * channels being configured.
255 */
256 if (i == pwm->hwpwm)
257 continue;
258
259 dev_err(chip->dev,
260 "period value conflicts with channel %u\n",
261 i);
262 return -EINVAL;
263 }
264 }
265
266 pc->period_cycles[pwm->hwpwm] = period_cycles;
267
268 /* Configure clock prescaler to support Low frequency PWM wave */
269 if (set_prescale_div(period_cycles/PERIOD_MAX, &ps_divval,
270 &tb_divval)) {
271 dev_err(chip->dev, "Unsupported values\n");
272 return -EINVAL;
273 }
274
275 pm_runtime_get_sync(chip->dev);
276
277 /* Update clock prescaler values */
278 ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_CLKDIV_MASK, tb_divval);
279
280 /* Update period & duty cycle with presacler division */
281 period_cycles = period_cycles / ps_divval;
282 duty_cycles = duty_cycles / ps_divval;
283
284 /* Configure shadow loading on Period register */
285 ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_PRDLD_MASK, TBCTL_PRDLD_SHDW);
286
287 ehrpwm_write(pc->mmio_base, TBPRD, period_cycles);
288
289 /* Configure ehrpwm counter for up-count mode */
290 ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_CTRMODE_MASK,
291 TBCTL_CTRMODE_UP);
292
293 if (pwm->hwpwm == 1)
294 /* Channel 1 configured with compare B register */
295 cmp_reg = CMPB;
296 else
297 /* Channel 0 configured with compare A register */
298 cmp_reg = CMPA;
299
300 ehrpwm_write(pc->mmio_base, cmp_reg, duty_cycles);
301
302 pm_runtime_put_sync(chip->dev);
303
304 return 0;
305}
306
307static int ehrpwm_pwm_set_polarity(struct pwm_chip *chip,
308 struct pwm_device *pwm,
309 enum pwm_polarity polarity)
310{
311 struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
312
313 /* Configuration of polarity in hardware delayed, do at enable */
314 pc->polarity[pwm->hwpwm] = polarity;
315
316 return 0;
317}
318
319static int ehrpwm_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
320{
321 struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
322 u16 aqcsfrc_val, aqcsfrc_mask;
323 int ret;
324
325 /* Leave clock enabled on enabling PWM */
326 pm_runtime_get_sync(chip->dev);
327
328 /* Disabling Action Qualifier on PWM output */
329 if (pwm->hwpwm) {
330 aqcsfrc_val = AQCSFRC_CSFB_FRCDIS;
331 aqcsfrc_mask = AQCSFRC_CSFB_MASK;
332 } else {
333 aqcsfrc_val = AQCSFRC_CSFA_FRCDIS;
334 aqcsfrc_mask = AQCSFRC_CSFA_MASK;
335 }
336
337 /* Changes to shadow mode */
338 ehrpwm_modify(pc->mmio_base, AQSFRC, AQSFRC_RLDCSF_MASK,
339 AQSFRC_RLDCSF_ZRO);
340
341 ehrpwm_modify(pc->mmio_base, AQCSFRC, aqcsfrc_mask, aqcsfrc_val);
342
343 /* Channels polarity can be configured from action qualifier module */
344 configure_polarity(pc, pwm->hwpwm);
345
346 /* Enable TBCLK */
347 ret = clk_enable(pc->tbclk);
348 if (ret) {
349 dev_err(chip->dev, "Failed to enable TBCLK for %s: %d\n",
350 dev_name(pc->chip.dev), ret);
351 return ret;
352 }
353
354 return 0;
355}
356
357static void ehrpwm_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
358{
359 struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
360 u16 aqcsfrc_val, aqcsfrc_mask;
361
362 /* Action Qualifier puts PWM output low forcefully */
363 if (pwm->hwpwm) {
364 aqcsfrc_val = AQCSFRC_CSFB_FRCLOW;
365 aqcsfrc_mask = AQCSFRC_CSFB_MASK;
366 } else {
367 aqcsfrc_val = AQCSFRC_CSFA_FRCLOW;
368 aqcsfrc_mask = AQCSFRC_CSFA_MASK;
369 }
370
371 /* Update shadow register first before modifying active register */
372 ehrpwm_modify(pc->mmio_base, AQSFRC, AQSFRC_RLDCSF_MASK,
373 AQSFRC_RLDCSF_ZRO);
374 ehrpwm_modify(pc->mmio_base, AQCSFRC, aqcsfrc_mask, aqcsfrc_val);
375 /*
376 * Changes to immediate action on Action Qualifier. This puts
377 * Action Qualifier control on PWM output from next TBCLK
378 */
379 ehrpwm_modify(pc->mmio_base, AQSFRC, AQSFRC_RLDCSF_MASK,
380 AQSFRC_RLDCSF_IMDT);
381
382 ehrpwm_modify(pc->mmio_base, AQCSFRC, aqcsfrc_mask, aqcsfrc_val);
383
384 /* Disabling TBCLK on PWM disable */
385 clk_disable(pc->tbclk);
386
387 /* Disable clock on PWM disable */
388 pm_runtime_put_sync(chip->dev);
389}
390
391static void ehrpwm_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
392{
393 struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
394
395 if (pwm_is_enabled(pwm)) {
396 dev_warn(chip->dev, "Removing PWM device without disabling\n");
397 pm_runtime_put_sync(chip->dev);
398 }
399
400 /* set period value to zero on free */
401 pc->period_cycles[pwm->hwpwm] = 0;
402}
403
404static const struct pwm_ops ehrpwm_pwm_ops = {
405 .free = ehrpwm_pwm_free,
406 .config = ehrpwm_pwm_config,
407 .set_polarity = ehrpwm_pwm_set_polarity,
408 .enable = ehrpwm_pwm_enable,
409 .disable = ehrpwm_pwm_disable,
410 .owner = THIS_MODULE,
411};
412
413static const struct of_device_id ehrpwm_of_match[] = {
414 { .compatible = "ti,am3352-ehrpwm" },
415 { .compatible = "ti,am33xx-ehrpwm" },
416 {},
417};
418MODULE_DEVICE_TABLE(of, ehrpwm_of_match);
419
420static int ehrpwm_pwm_probe(struct platform_device *pdev)
421{
422 struct device_node *np = pdev->dev.of_node;
423 struct ehrpwm_pwm_chip *pc;
424 struct resource *r;
425 struct clk *clk;
426 int ret;
427
428 pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);
429 if (!pc)
430 return -ENOMEM;
431
432 clk = devm_clk_get(&pdev->dev, "fck");
433 if (IS_ERR(clk)) {
434 if (of_device_is_compatible(np, "ti,am33xx-ecap")) {
435 dev_warn(&pdev->dev, "Binding is obsolete.\n");
436 clk = devm_clk_get(pdev->dev.parent, "fck");
437 }
438 }
439
440 if (IS_ERR(clk)) {
441 dev_err(&pdev->dev, "failed to get clock\n");
442 return PTR_ERR(clk);
443 }
444
445 pc->clk_rate = clk_get_rate(clk);
446 if (!pc->clk_rate) {
447 dev_err(&pdev->dev, "failed to get clock rate\n");
448 return -EINVAL;
449 }
450
451 pc->chip.dev = &pdev->dev;
452 pc->chip.ops = &ehrpwm_pwm_ops;
453 pc->chip.of_xlate = of_pwm_xlate_with_flags;
454 pc->chip.of_pwm_n_cells = 3;
455 pc->chip.base = -1;
456 pc->chip.npwm = NUM_PWM_CHANNEL;
457
458 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
459 pc->mmio_base = devm_ioremap_resource(&pdev->dev, r);
460 if (IS_ERR(pc->mmio_base))
461 return PTR_ERR(pc->mmio_base);
462
463 /* Acquire tbclk for Time Base EHRPWM submodule */
464 pc->tbclk = devm_clk_get(&pdev->dev, "tbclk");
465 if (IS_ERR(pc->tbclk)) {
466 dev_err(&pdev->dev, "Failed to get tbclk\n");
467 return PTR_ERR(pc->tbclk);
468 }
469
470 ret = clk_prepare(pc->tbclk);
471 if (ret < 0) {
472 dev_err(&pdev->dev, "clk_prepare() failed: %d\n", ret);
473 return ret;
474 }
475
476 ret = pwmchip_add(&pc->chip);
477 if (ret < 0) {
478 dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
479 goto err_clk_unprepare;
480 }
481
482 platform_set_drvdata(pdev, pc);
483 pm_runtime_enable(&pdev->dev);
484
485 return 0;
486
487err_clk_unprepare:
488 clk_unprepare(pc->tbclk);
489
490 return ret;
491}
492
493static int ehrpwm_pwm_remove(struct platform_device *pdev)
494{
495 struct ehrpwm_pwm_chip *pc = platform_get_drvdata(pdev);
496
497 clk_unprepare(pc->tbclk);
498
499 pm_runtime_disable(&pdev->dev);
500
501 return pwmchip_remove(&pc->chip);
502}
503
504#ifdef CONFIG_PM_SLEEP
505static void ehrpwm_pwm_save_context(struct ehrpwm_pwm_chip *pc)
506{
507 pm_runtime_get_sync(pc->chip.dev);
508
509 pc->ctx.tbctl = ehrpwm_read(pc->mmio_base, TBCTL);
510 pc->ctx.tbprd = ehrpwm_read(pc->mmio_base, TBPRD);
511 pc->ctx.cmpa = ehrpwm_read(pc->mmio_base, CMPA);
512 pc->ctx.cmpb = ehrpwm_read(pc->mmio_base, CMPB);
513 pc->ctx.aqctla = ehrpwm_read(pc->mmio_base, AQCTLA);
514 pc->ctx.aqctlb = ehrpwm_read(pc->mmio_base, AQCTLB);
515 pc->ctx.aqsfrc = ehrpwm_read(pc->mmio_base, AQSFRC);
516 pc->ctx.aqcsfrc = ehrpwm_read(pc->mmio_base, AQCSFRC);
517
518 pm_runtime_put_sync(pc->chip.dev);
519}
520
521static void ehrpwm_pwm_restore_context(struct ehrpwm_pwm_chip *pc)
522{
523 ehrpwm_write(pc->mmio_base, TBPRD, pc->ctx.tbprd);
524 ehrpwm_write(pc->mmio_base, CMPA, pc->ctx.cmpa);
525 ehrpwm_write(pc->mmio_base, CMPB, pc->ctx.cmpb);
526 ehrpwm_write(pc->mmio_base, AQCTLA, pc->ctx.aqctla);
527 ehrpwm_write(pc->mmio_base, AQCTLB, pc->ctx.aqctlb);
528 ehrpwm_write(pc->mmio_base, AQSFRC, pc->ctx.aqsfrc);
529 ehrpwm_write(pc->mmio_base, AQCSFRC, pc->ctx.aqcsfrc);
530 ehrpwm_write(pc->mmio_base, TBCTL, pc->ctx.tbctl);
531}
532
533static int ehrpwm_pwm_suspend(struct device *dev)
534{
535 struct ehrpwm_pwm_chip *pc = dev_get_drvdata(dev);
536 unsigned int i;
537
538 ehrpwm_pwm_save_context(pc);
539
540 for (i = 0; i < pc->chip.npwm; i++) {
541 struct pwm_device *pwm = &pc->chip.pwms[i];
542
543 if (!pwm_is_enabled(pwm))
544 continue;
545
546 /* Disable explicitly if PWM is running */
547 pm_runtime_put_sync(dev);
548 }
549
550 return 0;
551}
552
553static int ehrpwm_pwm_resume(struct device *dev)
554{
555 struct ehrpwm_pwm_chip *pc = dev_get_drvdata(dev);
556 unsigned int i;
557
558 for (i = 0; i < pc->chip.npwm; i++) {
559 struct pwm_device *pwm = &pc->chip.pwms[i];
560
561 if (!pwm_is_enabled(pwm))
562 continue;
563
564 /* Enable explicitly if PWM was running */
565 pm_runtime_get_sync(dev);
566 }
567
568 ehrpwm_pwm_restore_context(pc);
569
570 return 0;
571}
572#endif
573
574static SIMPLE_DEV_PM_OPS(ehrpwm_pwm_pm_ops, ehrpwm_pwm_suspend,
575 ehrpwm_pwm_resume);
576
577static struct platform_driver ehrpwm_pwm_driver = {
578 .driver = {
579 .name = "ehrpwm",
580 .of_match_table = ehrpwm_of_match,
581 .pm = &ehrpwm_pwm_pm_ops,
582 },
583 .probe = ehrpwm_pwm_probe,
584 .remove = ehrpwm_pwm_remove,
585};
586module_platform_driver(ehrpwm_pwm_driver);
587
588MODULE_DESCRIPTION("EHRPWM PWM driver");
589MODULE_AUTHOR("Texas Instruments");
590MODULE_LICENSE("GPL");
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * EHRPWM PWM driver
4 *
5 * Copyright (C) 2012 Texas Instruments, Inc. - https://www.ti.com/
6 */
7
8#include <linux/module.h>
9#include <linux/platform_device.h>
10#include <linux/pwm.h>
11#include <linux/io.h>
12#include <linux/err.h>
13#include <linux/clk.h>
14#include <linux/pm_runtime.h>
15#include <linux/of_device.h>
16
17/* EHRPWM registers and bits definitions */
18
19/* Time base module registers */
20#define TBCTL 0x00
21#define TBPRD 0x0A
22
23#define TBCTL_PRDLD_MASK BIT(3)
24#define TBCTL_PRDLD_SHDW 0
25#define TBCTL_PRDLD_IMDT BIT(3)
26#define TBCTL_CLKDIV_MASK (BIT(12) | BIT(11) | BIT(10) | BIT(9) | \
27 BIT(8) | BIT(7))
28#define TBCTL_CTRMODE_MASK (BIT(1) | BIT(0))
29#define TBCTL_CTRMODE_UP 0
30#define TBCTL_CTRMODE_DOWN BIT(0)
31#define TBCTL_CTRMODE_UPDOWN BIT(1)
32#define TBCTL_CTRMODE_FREEZE (BIT(1) | BIT(0))
33
34#define TBCTL_HSPCLKDIV_SHIFT 7
35#define TBCTL_CLKDIV_SHIFT 10
36
37#define CLKDIV_MAX 7
38#define HSPCLKDIV_MAX 7
39#define PERIOD_MAX 0xFFFF
40
41/* compare module registers */
42#define CMPA 0x12
43#define CMPB 0x14
44
45/* Action qualifier module registers */
46#define AQCTLA 0x16
47#define AQCTLB 0x18
48#define AQSFRC 0x1A
49#define AQCSFRC 0x1C
50
51#define AQCTL_CBU_MASK (BIT(9) | BIT(8))
52#define AQCTL_CBU_FRCLOW BIT(8)
53#define AQCTL_CBU_FRCHIGH BIT(9)
54#define AQCTL_CBU_FRCTOGGLE (BIT(9) | BIT(8))
55#define AQCTL_CAU_MASK (BIT(5) | BIT(4))
56#define AQCTL_CAU_FRCLOW BIT(4)
57#define AQCTL_CAU_FRCHIGH BIT(5)
58#define AQCTL_CAU_FRCTOGGLE (BIT(5) | BIT(4))
59#define AQCTL_PRD_MASK (BIT(3) | BIT(2))
60#define AQCTL_PRD_FRCLOW BIT(2)
61#define AQCTL_PRD_FRCHIGH BIT(3)
62#define AQCTL_PRD_FRCTOGGLE (BIT(3) | BIT(2))
63#define AQCTL_ZRO_MASK (BIT(1) | BIT(0))
64#define AQCTL_ZRO_FRCLOW BIT(0)
65#define AQCTL_ZRO_FRCHIGH BIT(1)
66#define AQCTL_ZRO_FRCTOGGLE (BIT(1) | BIT(0))
67
68#define AQCTL_CHANA_POLNORMAL (AQCTL_CAU_FRCLOW | AQCTL_PRD_FRCHIGH | \
69 AQCTL_ZRO_FRCHIGH)
70#define AQCTL_CHANA_POLINVERSED (AQCTL_CAU_FRCHIGH | AQCTL_PRD_FRCLOW | \
71 AQCTL_ZRO_FRCLOW)
72#define AQCTL_CHANB_POLNORMAL (AQCTL_CBU_FRCLOW | AQCTL_PRD_FRCHIGH | \
73 AQCTL_ZRO_FRCHIGH)
74#define AQCTL_CHANB_POLINVERSED (AQCTL_CBU_FRCHIGH | AQCTL_PRD_FRCLOW | \
75 AQCTL_ZRO_FRCLOW)
76
77#define AQSFRC_RLDCSF_MASK (BIT(7) | BIT(6))
78#define AQSFRC_RLDCSF_ZRO 0
79#define AQSFRC_RLDCSF_PRD BIT(6)
80#define AQSFRC_RLDCSF_ZROPRD BIT(7)
81#define AQSFRC_RLDCSF_IMDT (BIT(7) | BIT(6))
82
83#define AQCSFRC_CSFB_MASK (BIT(3) | BIT(2))
84#define AQCSFRC_CSFB_FRCDIS 0
85#define AQCSFRC_CSFB_FRCLOW BIT(2)
86#define AQCSFRC_CSFB_FRCHIGH BIT(3)
87#define AQCSFRC_CSFB_DISSWFRC (BIT(3) | BIT(2))
88#define AQCSFRC_CSFA_MASK (BIT(1) | BIT(0))
89#define AQCSFRC_CSFA_FRCDIS 0
90#define AQCSFRC_CSFA_FRCLOW BIT(0)
91#define AQCSFRC_CSFA_FRCHIGH BIT(1)
92#define AQCSFRC_CSFA_DISSWFRC (BIT(1) | BIT(0))
93
94#define NUM_PWM_CHANNEL 2 /* EHRPWM channels */
95
96struct ehrpwm_context {
97 u16 tbctl;
98 u16 tbprd;
99 u16 cmpa;
100 u16 cmpb;
101 u16 aqctla;
102 u16 aqctlb;
103 u16 aqsfrc;
104 u16 aqcsfrc;
105};
106
107struct ehrpwm_pwm_chip {
108 struct pwm_chip chip;
109 unsigned long clk_rate;
110 void __iomem *mmio_base;
111 unsigned long period_cycles[NUM_PWM_CHANNEL];
112 enum pwm_polarity polarity[NUM_PWM_CHANNEL];
113 struct clk *tbclk;
114 struct ehrpwm_context ctx;
115};
116
117static inline struct ehrpwm_pwm_chip *to_ehrpwm_pwm_chip(struct pwm_chip *chip)
118{
119 return container_of(chip, struct ehrpwm_pwm_chip, chip);
120}
121
122static inline u16 ehrpwm_read(void __iomem *base, unsigned int offset)
123{
124 return readw(base + offset);
125}
126
127static inline void ehrpwm_write(void __iomem *base, unsigned int offset,
128 u16 value)
129{
130 writew(value, base + offset);
131}
132
133static void ehrpwm_modify(void __iomem *base, unsigned int offset, u16 mask,
134 u16 value)
135{
136 unsigned short val;
137
138 val = readw(base + offset);
139 val &= ~mask;
140 val |= value & mask;
141 writew(val, base + offset);
142}
143
144/**
145 * set_prescale_div - Set up the prescaler divider function
146 * @rqst_prescaler: prescaler value min
147 * @prescale_div: prescaler value set
148 * @tb_clk_div: Time Base Control prescaler bits
149 */
150static int set_prescale_div(unsigned long rqst_prescaler, u16 *prescale_div,
151 u16 *tb_clk_div)
152{
153 unsigned int clkdiv, hspclkdiv;
154
155 for (clkdiv = 0; clkdiv <= CLKDIV_MAX; clkdiv++) {
156 for (hspclkdiv = 0; hspclkdiv <= HSPCLKDIV_MAX; hspclkdiv++) {
157 /*
158 * calculations for prescaler value :
159 * prescale_div = HSPCLKDIVIDER * CLKDIVIDER.
160 * HSPCLKDIVIDER = 2 ** hspclkdiv
161 * CLKDIVIDER = (1), if clkdiv == 0 *OR*
162 * (2 * clkdiv), if clkdiv != 0
163 *
164 * Configure prescale_div value such that period
165 * register value is less than 65535.
166 */
167
168 *prescale_div = (1 << clkdiv) *
169 (hspclkdiv ? (hspclkdiv * 2) : 1);
170 if (*prescale_div > rqst_prescaler) {
171 *tb_clk_div = (clkdiv << TBCTL_CLKDIV_SHIFT) |
172 (hspclkdiv << TBCTL_HSPCLKDIV_SHIFT);
173 return 0;
174 }
175 }
176 }
177
178 return 1;
179}
180
181static void configure_polarity(struct ehrpwm_pwm_chip *pc, int chan)
182{
183 u16 aqctl_val, aqctl_mask;
184 unsigned int aqctl_reg;
185
186 /*
187 * Configure PWM output to HIGH/LOW level on counter
188 * reaches compare register value and LOW/HIGH level
189 * on counter value reaches period register value and
190 * zero value on counter
191 */
192 if (chan == 1) {
193 aqctl_reg = AQCTLB;
194 aqctl_mask = AQCTL_CBU_MASK;
195
196 if (pc->polarity[chan] == PWM_POLARITY_INVERSED)
197 aqctl_val = AQCTL_CHANB_POLINVERSED;
198 else
199 aqctl_val = AQCTL_CHANB_POLNORMAL;
200 } else {
201 aqctl_reg = AQCTLA;
202 aqctl_mask = AQCTL_CAU_MASK;
203
204 if (pc->polarity[chan] == PWM_POLARITY_INVERSED)
205 aqctl_val = AQCTL_CHANA_POLINVERSED;
206 else
207 aqctl_val = AQCTL_CHANA_POLNORMAL;
208 }
209
210 aqctl_mask |= AQCTL_PRD_MASK | AQCTL_ZRO_MASK;
211 ehrpwm_modify(pc->mmio_base, aqctl_reg, aqctl_mask, aqctl_val);
212}
213
214/*
215 * period_ns = 10^9 * (ps_divval * period_cycles) / PWM_CLK_RATE
216 * duty_ns = 10^9 * (ps_divval * duty_cycles) / PWM_CLK_RATE
217 */
218static int ehrpwm_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
219 u64 duty_ns, u64 period_ns)
220{
221 struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
222 u32 period_cycles, duty_cycles;
223 u16 ps_divval, tb_divval;
224 unsigned int i, cmp_reg;
225 unsigned long long c;
226
227 if (period_ns > NSEC_PER_SEC)
228 return -ERANGE;
229
230 c = pc->clk_rate;
231 c = c * period_ns;
232 do_div(c, NSEC_PER_SEC);
233 period_cycles = (unsigned long)c;
234
235 if (period_cycles < 1) {
236 period_cycles = 1;
237 duty_cycles = 1;
238 } else {
239 c = pc->clk_rate;
240 c = c * duty_ns;
241 do_div(c, NSEC_PER_SEC);
242 duty_cycles = (unsigned long)c;
243 }
244
245 /*
246 * Period values should be same for multiple PWM channels as IP uses
247 * same period register for multiple channels.
248 */
249 for (i = 0; i < NUM_PWM_CHANNEL; i++) {
250 if (pc->period_cycles[i] &&
251 (pc->period_cycles[i] != period_cycles)) {
252 /*
253 * Allow channel to reconfigure period if no other
254 * channels being configured.
255 */
256 if (i == pwm->hwpwm)
257 continue;
258
259 dev_err(chip->dev,
260 "period value conflicts with channel %u\n",
261 i);
262 return -EINVAL;
263 }
264 }
265
266 pc->period_cycles[pwm->hwpwm] = period_cycles;
267
268 /* Configure clock prescaler to support Low frequency PWM wave */
269 if (set_prescale_div(period_cycles/PERIOD_MAX, &ps_divval,
270 &tb_divval)) {
271 dev_err(chip->dev, "Unsupported values\n");
272 return -EINVAL;
273 }
274
275 pm_runtime_get_sync(chip->dev);
276
277 /* Update clock prescaler values */
278 ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_CLKDIV_MASK, tb_divval);
279
280 /* Update period & duty cycle with presacler division */
281 period_cycles = period_cycles / ps_divval;
282 duty_cycles = duty_cycles / ps_divval;
283
284 /* Configure shadow loading on Period register */
285 ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_PRDLD_MASK, TBCTL_PRDLD_SHDW);
286
287 ehrpwm_write(pc->mmio_base, TBPRD, period_cycles);
288
289 /* Configure ehrpwm counter for up-count mode */
290 ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_CTRMODE_MASK,
291 TBCTL_CTRMODE_UP);
292
293 if (pwm->hwpwm == 1)
294 /* Channel 1 configured with compare B register */
295 cmp_reg = CMPB;
296 else
297 /* Channel 0 configured with compare A register */
298 cmp_reg = CMPA;
299
300 ehrpwm_write(pc->mmio_base, cmp_reg, duty_cycles);
301
302 pm_runtime_put_sync(chip->dev);
303
304 return 0;
305}
306
307static int ehrpwm_pwm_set_polarity(struct pwm_chip *chip,
308 struct pwm_device *pwm,
309 enum pwm_polarity polarity)
310{
311 struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
312
313 /* Configuration of polarity in hardware delayed, do at enable */
314 pc->polarity[pwm->hwpwm] = polarity;
315
316 return 0;
317}
318
319static int ehrpwm_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
320{
321 struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
322 u16 aqcsfrc_val, aqcsfrc_mask;
323 int ret;
324
325 /* Leave clock enabled on enabling PWM */
326 pm_runtime_get_sync(chip->dev);
327
328 /* Disabling Action Qualifier on PWM output */
329 if (pwm->hwpwm) {
330 aqcsfrc_val = AQCSFRC_CSFB_FRCDIS;
331 aqcsfrc_mask = AQCSFRC_CSFB_MASK;
332 } else {
333 aqcsfrc_val = AQCSFRC_CSFA_FRCDIS;
334 aqcsfrc_mask = AQCSFRC_CSFA_MASK;
335 }
336
337 /* Changes to shadow mode */
338 ehrpwm_modify(pc->mmio_base, AQSFRC, AQSFRC_RLDCSF_MASK,
339 AQSFRC_RLDCSF_ZRO);
340
341 ehrpwm_modify(pc->mmio_base, AQCSFRC, aqcsfrc_mask, aqcsfrc_val);
342
343 /* Channels polarity can be configured from action qualifier module */
344 configure_polarity(pc, pwm->hwpwm);
345
346 /* Enable TBCLK */
347 ret = clk_enable(pc->tbclk);
348 if (ret) {
349 dev_err(chip->dev, "Failed to enable TBCLK for %s: %d\n",
350 dev_name(pc->chip.dev), ret);
351 return ret;
352 }
353
354 return 0;
355}
356
357static void ehrpwm_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
358{
359 struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
360 u16 aqcsfrc_val, aqcsfrc_mask;
361
362 /* Action Qualifier puts PWM output low forcefully */
363 if (pwm->hwpwm) {
364 aqcsfrc_val = AQCSFRC_CSFB_FRCLOW;
365 aqcsfrc_mask = AQCSFRC_CSFB_MASK;
366 } else {
367 aqcsfrc_val = AQCSFRC_CSFA_FRCLOW;
368 aqcsfrc_mask = AQCSFRC_CSFA_MASK;
369 }
370
371 /* Update shadow register first before modifying active register */
372 ehrpwm_modify(pc->mmio_base, AQSFRC, AQSFRC_RLDCSF_MASK,
373 AQSFRC_RLDCSF_ZRO);
374 ehrpwm_modify(pc->mmio_base, AQCSFRC, aqcsfrc_mask, aqcsfrc_val);
375 /*
376 * Changes to immediate action on Action Qualifier. This puts
377 * Action Qualifier control on PWM output from next TBCLK
378 */
379 ehrpwm_modify(pc->mmio_base, AQSFRC, AQSFRC_RLDCSF_MASK,
380 AQSFRC_RLDCSF_IMDT);
381
382 ehrpwm_modify(pc->mmio_base, AQCSFRC, aqcsfrc_mask, aqcsfrc_val);
383
384 /* Disabling TBCLK on PWM disable */
385 clk_disable(pc->tbclk);
386
387 /* Disable clock on PWM disable */
388 pm_runtime_put_sync(chip->dev);
389}
390
391static void ehrpwm_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
392{
393 struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
394
395 if (pwm_is_enabled(pwm)) {
396 dev_warn(chip->dev, "Removing PWM device without disabling\n");
397 pm_runtime_put_sync(chip->dev);
398 }
399
400 /* set period value to zero on free */
401 pc->period_cycles[pwm->hwpwm] = 0;
402}
403
404static int ehrpwm_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
405 const struct pwm_state *state)
406{
407 int err;
408 bool enabled = pwm->state.enabled;
409
410 if (state->polarity != pwm->state.polarity) {
411 if (enabled) {
412 ehrpwm_pwm_disable(chip, pwm);
413 enabled = false;
414 }
415
416 err = ehrpwm_pwm_set_polarity(chip, pwm, state->polarity);
417 if (err)
418 return err;
419 }
420
421 if (!state->enabled) {
422 if (enabled)
423 ehrpwm_pwm_disable(chip, pwm);
424 return 0;
425 }
426
427 err = ehrpwm_pwm_config(chip, pwm, state->duty_cycle, state->period);
428 if (err)
429 return err;
430
431 if (!enabled)
432 err = ehrpwm_pwm_enable(chip, pwm);
433
434 return err;
435}
436
437static const struct pwm_ops ehrpwm_pwm_ops = {
438 .free = ehrpwm_pwm_free,
439 .apply = ehrpwm_pwm_apply,
440 .owner = THIS_MODULE,
441};
442
443static const struct of_device_id ehrpwm_of_match[] = {
444 { .compatible = "ti,am3352-ehrpwm" },
445 { .compatible = "ti,am33xx-ehrpwm" },
446 {},
447};
448MODULE_DEVICE_TABLE(of, ehrpwm_of_match);
449
450static int ehrpwm_pwm_probe(struct platform_device *pdev)
451{
452 struct device_node *np = pdev->dev.of_node;
453 struct ehrpwm_pwm_chip *pc;
454 struct clk *clk;
455 int ret;
456
457 pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);
458 if (!pc)
459 return -ENOMEM;
460
461 clk = devm_clk_get(&pdev->dev, "fck");
462 if (IS_ERR(clk)) {
463 if (of_device_is_compatible(np, "ti,am33xx-ecap")) {
464 dev_warn(&pdev->dev, "Binding is obsolete.\n");
465 clk = devm_clk_get(pdev->dev.parent, "fck");
466 }
467 }
468
469 if (IS_ERR(clk))
470 return dev_err_probe(&pdev->dev, PTR_ERR(clk), "Failed to get fck\n");
471
472 pc->clk_rate = clk_get_rate(clk);
473 if (!pc->clk_rate) {
474 dev_err(&pdev->dev, "failed to get clock rate\n");
475 return -EINVAL;
476 }
477
478 pc->chip.dev = &pdev->dev;
479 pc->chip.ops = &ehrpwm_pwm_ops;
480 pc->chip.npwm = NUM_PWM_CHANNEL;
481
482 pc->mmio_base = devm_platform_ioremap_resource(pdev, 0);
483 if (IS_ERR(pc->mmio_base))
484 return PTR_ERR(pc->mmio_base);
485
486 /* Acquire tbclk for Time Base EHRPWM submodule */
487 pc->tbclk = devm_clk_get(&pdev->dev, "tbclk");
488 if (IS_ERR(pc->tbclk))
489 return dev_err_probe(&pdev->dev, PTR_ERR(pc->tbclk), "Failed to get tbclk\n");
490
491 ret = clk_prepare(pc->tbclk);
492 if (ret < 0) {
493 dev_err(&pdev->dev, "clk_prepare() failed: %d\n", ret);
494 return ret;
495 }
496
497 ret = pwmchip_add(&pc->chip);
498 if (ret < 0) {
499 dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
500 goto err_clk_unprepare;
501 }
502
503 platform_set_drvdata(pdev, pc);
504 pm_runtime_enable(&pdev->dev);
505
506 return 0;
507
508err_clk_unprepare:
509 clk_unprepare(pc->tbclk);
510
511 return ret;
512}
513
514static int ehrpwm_pwm_remove(struct platform_device *pdev)
515{
516 struct ehrpwm_pwm_chip *pc = platform_get_drvdata(pdev);
517
518 pwmchip_remove(&pc->chip);
519
520 clk_unprepare(pc->tbclk);
521
522 pm_runtime_disable(&pdev->dev);
523
524 return 0;
525}
526
527#ifdef CONFIG_PM_SLEEP
528static void ehrpwm_pwm_save_context(struct ehrpwm_pwm_chip *pc)
529{
530 pm_runtime_get_sync(pc->chip.dev);
531
532 pc->ctx.tbctl = ehrpwm_read(pc->mmio_base, TBCTL);
533 pc->ctx.tbprd = ehrpwm_read(pc->mmio_base, TBPRD);
534 pc->ctx.cmpa = ehrpwm_read(pc->mmio_base, CMPA);
535 pc->ctx.cmpb = ehrpwm_read(pc->mmio_base, CMPB);
536 pc->ctx.aqctla = ehrpwm_read(pc->mmio_base, AQCTLA);
537 pc->ctx.aqctlb = ehrpwm_read(pc->mmio_base, AQCTLB);
538 pc->ctx.aqsfrc = ehrpwm_read(pc->mmio_base, AQSFRC);
539 pc->ctx.aqcsfrc = ehrpwm_read(pc->mmio_base, AQCSFRC);
540
541 pm_runtime_put_sync(pc->chip.dev);
542}
543
544static void ehrpwm_pwm_restore_context(struct ehrpwm_pwm_chip *pc)
545{
546 ehrpwm_write(pc->mmio_base, TBPRD, pc->ctx.tbprd);
547 ehrpwm_write(pc->mmio_base, CMPA, pc->ctx.cmpa);
548 ehrpwm_write(pc->mmio_base, CMPB, pc->ctx.cmpb);
549 ehrpwm_write(pc->mmio_base, AQCTLA, pc->ctx.aqctla);
550 ehrpwm_write(pc->mmio_base, AQCTLB, pc->ctx.aqctlb);
551 ehrpwm_write(pc->mmio_base, AQSFRC, pc->ctx.aqsfrc);
552 ehrpwm_write(pc->mmio_base, AQCSFRC, pc->ctx.aqcsfrc);
553 ehrpwm_write(pc->mmio_base, TBCTL, pc->ctx.tbctl);
554}
555
556static int ehrpwm_pwm_suspend(struct device *dev)
557{
558 struct ehrpwm_pwm_chip *pc = dev_get_drvdata(dev);
559 unsigned int i;
560
561 ehrpwm_pwm_save_context(pc);
562
563 for (i = 0; i < pc->chip.npwm; i++) {
564 struct pwm_device *pwm = &pc->chip.pwms[i];
565
566 if (!pwm_is_enabled(pwm))
567 continue;
568
569 /* Disable explicitly if PWM is running */
570 pm_runtime_put_sync(dev);
571 }
572
573 return 0;
574}
575
576static int ehrpwm_pwm_resume(struct device *dev)
577{
578 struct ehrpwm_pwm_chip *pc = dev_get_drvdata(dev);
579 unsigned int i;
580
581 for (i = 0; i < pc->chip.npwm; i++) {
582 struct pwm_device *pwm = &pc->chip.pwms[i];
583
584 if (!pwm_is_enabled(pwm))
585 continue;
586
587 /* Enable explicitly if PWM was running */
588 pm_runtime_get_sync(dev);
589 }
590
591 ehrpwm_pwm_restore_context(pc);
592
593 return 0;
594}
595#endif
596
597static SIMPLE_DEV_PM_OPS(ehrpwm_pwm_pm_ops, ehrpwm_pwm_suspend,
598 ehrpwm_pwm_resume);
599
600static struct platform_driver ehrpwm_pwm_driver = {
601 .driver = {
602 .name = "ehrpwm",
603 .of_match_table = ehrpwm_of_match,
604 .pm = &ehrpwm_pwm_pm_ops,
605 },
606 .probe = ehrpwm_pwm_probe,
607 .remove = ehrpwm_pwm_remove,
608};
609module_platform_driver(ehrpwm_pwm_driver);
610
611MODULE_DESCRIPTION("EHRPWM PWM driver");
612MODULE_AUTHOR("Texas Instruments");
613MODULE_LICENSE("GPL");