WIP FPC-III support
[linux/fpc-iii.git] / drivers / pwm / pwm-tiehrpwm.c
bloba7fb224d65350cf054111ba547a99144924751fc
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * EHRPWM PWM driver
5 * Copyright (C) 2012 Texas Instruments, Inc. - https://www.ti.com/
6 */
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>
17 /* EHRPWM registers and bits definitions */
19 /* Time base module registers */
20 #define TBCTL 0x00
21 #define TBPRD 0x0A
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))
34 #define TBCTL_HSPCLKDIV_SHIFT 7
35 #define TBCTL_CLKDIV_SHIFT 10
37 #define CLKDIV_MAX 7
38 #define HSPCLKDIV_MAX 7
39 #define PERIOD_MAX 0xFFFF
41 /* compare module registers */
42 #define CMPA 0x12
43 #define CMPB 0x14
45 /* Action qualifier module registers */
46 #define AQCTLA 0x16
47 #define AQCTLB 0x18
48 #define AQSFRC 0x1A
49 #define AQCSFRC 0x1C
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))
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)
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))
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))
94 #define NUM_PWM_CHANNEL 2 /* EHRPWM channels */
96 struct 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;
107 struct 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;
117 static inline struct ehrpwm_pwm_chip *to_ehrpwm_pwm_chip(struct pwm_chip *chip)
119 return container_of(chip, struct ehrpwm_pwm_chip, chip);
122 static inline u16 ehrpwm_read(void __iomem *base, unsigned int offset)
124 return readw(base + offset);
127 static inline void ehrpwm_write(void __iomem *base, unsigned int offset,
128 u16 value)
130 writew(value, base + offset);
133 static void ehrpwm_modify(void __iomem *base, unsigned int offset, u16 mask,
134 u16 value)
136 unsigned short val;
138 val = readw(base + offset);
139 val &= ~mask;
140 val |= value & mask;
141 writew(val, base + offset);
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
150 static int set_prescale_div(unsigned long rqst_prescaler, u16 *prescale_div,
151 u16 *tb_clk_div)
153 unsigned int clkdiv, hspclkdiv;
155 for (clkdiv = 0; clkdiv <= CLKDIV_MAX; clkdiv++) {
156 for (hspclkdiv = 0; hspclkdiv <= HSPCLKDIV_MAX; hspclkdiv++) {
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
164 * Configure prescale_div value such that period
165 * register value is less than 65535.
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;
178 return 1;
181 static void configure_polarity(struct ehrpwm_pwm_chip *pc, int chan)
183 u16 aqctl_val, aqctl_mask;
184 unsigned int aqctl_reg;
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
192 if (chan == 1) {
193 aqctl_reg = AQCTLB;
194 aqctl_mask = AQCTL_CBU_MASK;
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;
204 if (pc->polarity[chan] == PWM_POLARITY_INVERSED)
205 aqctl_val = AQCTL_CHANA_POLINVERSED;
206 else
207 aqctl_val = AQCTL_CHANA_POLNORMAL;
210 aqctl_mask |= AQCTL_PRD_MASK | AQCTL_ZRO_MASK;
211 ehrpwm_modify(pc->mmio_base, aqctl_reg, aqctl_mask, aqctl_val);
215 * period_ns = 10^9 * (ps_divval * period_cycles) / PWM_CLK_RATE
216 * duty_ns = 10^9 * (ps_divval * duty_cycles) / PWM_CLK_RATE
218 static int ehrpwm_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
219 int duty_ns, int period_ns)
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;
227 if (period_ns > NSEC_PER_SEC)
228 return -ERANGE;
230 c = pc->clk_rate;
231 c = c * period_ns;
232 do_div(c, NSEC_PER_SEC);
233 period_cycles = (unsigned long)c;
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;
246 * Period values should be same for multiple PWM channels as IP uses
247 * same period register for multiple channels.
249 for (i = 0; i < NUM_PWM_CHANNEL; i++) {
250 if (pc->period_cycles[i] &&
251 (pc->period_cycles[i] != period_cycles)) {
253 * Allow channel to reconfigure period if no other
254 * channels being configured.
256 if (i == pwm->hwpwm)
257 continue;
259 dev_err(chip->dev,
260 "period value conflicts with channel %u\n",
262 return -EINVAL;
266 pc->period_cycles[pwm->hwpwm] = period_cycles;
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;
275 pm_runtime_get_sync(chip->dev);
277 /* Update clock prescaler values */
278 ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_CLKDIV_MASK, tb_divval);
280 /* Update period & duty cycle with presacler division */
281 period_cycles = period_cycles / ps_divval;
282 duty_cycles = duty_cycles / ps_divval;
284 /* Configure shadow loading on Period register */
285 ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_PRDLD_MASK, TBCTL_PRDLD_SHDW);
287 ehrpwm_write(pc->mmio_base, TBPRD, period_cycles);
289 /* Configure ehrpwm counter for up-count mode */
290 ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_CTRMODE_MASK,
291 TBCTL_CTRMODE_UP);
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;
300 ehrpwm_write(pc->mmio_base, cmp_reg, duty_cycles);
302 pm_runtime_put_sync(chip->dev);
304 return 0;
307 static int ehrpwm_pwm_set_polarity(struct pwm_chip *chip,
308 struct pwm_device *pwm,
309 enum pwm_polarity polarity)
311 struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
313 /* Configuration of polarity in hardware delayed, do at enable */
314 pc->polarity[pwm->hwpwm] = polarity;
316 return 0;
319 static int ehrpwm_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
321 struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
322 u16 aqcsfrc_val, aqcsfrc_mask;
323 int ret;
325 /* Leave clock enabled on enabling PWM */
326 pm_runtime_get_sync(chip->dev);
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;
337 /* Changes to shadow mode */
338 ehrpwm_modify(pc->mmio_base, AQSFRC, AQSFRC_RLDCSF_MASK,
339 AQSFRC_RLDCSF_ZRO);
341 ehrpwm_modify(pc->mmio_base, AQCSFRC, aqcsfrc_mask, aqcsfrc_val);
343 /* Channels polarity can be configured from action qualifier module */
344 configure_polarity(pc, pwm->hwpwm);
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;
354 return 0;
357 static void ehrpwm_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
359 struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
360 u16 aqcsfrc_val, aqcsfrc_mask;
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;
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);
376 * Changes to immediate action on Action Qualifier. This puts
377 * Action Qualifier control on PWM output from next TBCLK
379 ehrpwm_modify(pc->mmio_base, AQSFRC, AQSFRC_RLDCSF_MASK,
380 AQSFRC_RLDCSF_IMDT);
382 ehrpwm_modify(pc->mmio_base, AQCSFRC, aqcsfrc_mask, aqcsfrc_val);
384 /* Disabling TBCLK on PWM disable */
385 clk_disable(pc->tbclk);
387 /* Disable clock on PWM disable */
388 pm_runtime_put_sync(chip->dev);
391 static void ehrpwm_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
393 struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
395 if (pwm_is_enabled(pwm)) {
396 dev_warn(chip->dev, "Removing PWM device without disabling\n");
397 pm_runtime_put_sync(chip->dev);
400 /* set period value to zero on free */
401 pc->period_cycles[pwm->hwpwm] = 0;
404 static 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,
413 static const struct of_device_id ehrpwm_of_match[] = {
414 { .compatible = "ti,am3352-ehrpwm" },
415 { .compatible = "ti,am33xx-ehrpwm" },
418 MODULE_DEVICE_TABLE(of, ehrpwm_of_match);
420 static int ehrpwm_pwm_probe(struct platform_device *pdev)
422 struct device_node *np = pdev->dev.of_node;
423 struct ehrpwm_pwm_chip *pc;
424 struct clk *clk;
425 int ret;
427 pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);
428 if (!pc)
429 return -ENOMEM;
431 clk = devm_clk_get(&pdev->dev, "fck");
432 if (IS_ERR(clk)) {
433 if (of_device_is_compatible(np, "ti,am33xx-ecap")) {
434 dev_warn(&pdev->dev, "Binding is obsolete.\n");
435 clk = devm_clk_get(pdev->dev.parent, "fck");
439 if (IS_ERR(clk))
440 return dev_err_probe(&pdev->dev, PTR_ERR(clk), "Failed to get fck\n");
442 pc->clk_rate = clk_get_rate(clk);
443 if (!pc->clk_rate) {
444 dev_err(&pdev->dev, "failed to get clock rate\n");
445 return -EINVAL;
448 pc->chip.dev = &pdev->dev;
449 pc->chip.ops = &ehrpwm_pwm_ops;
450 pc->chip.of_xlate = of_pwm_xlate_with_flags;
451 pc->chip.of_pwm_n_cells = 3;
452 pc->chip.base = -1;
453 pc->chip.npwm = NUM_PWM_CHANNEL;
455 pc->mmio_base = devm_platform_ioremap_resource(pdev, 0);
456 if (IS_ERR(pc->mmio_base))
457 return PTR_ERR(pc->mmio_base);
459 /* Acquire tbclk for Time Base EHRPWM submodule */
460 pc->tbclk = devm_clk_get(&pdev->dev, "tbclk");
461 if (IS_ERR(pc->tbclk))
462 return dev_err_probe(&pdev->dev, PTR_ERR(pc->tbclk), "Failed to get tbclk\n");
464 ret = clk_prepare(pc->tbclk);
465 if (ret < 0) {
466 dev_err(&pdev->dev, "clk_prepare() failed: %d\n", ret);
467 return ret;
470 ret = pwmchip_add(&pc->chip);
471 if (ret < 0) {
472 dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
473 goto err_clk_unprepare;
476 platform_set_drvdata(pdev, pc);
477 pm_runtime_enable(&pdev->dev);
479 return 0;
481 err_clk_unprepare:
482 clk_unprepare(pc->tbclk);
484 return ret;
487 static int ehrpwm_pwm_remove(struct platform_device *pdev)
489 struct ehrpwm_pwm_chip *pc = platform_get_drvdata(pdev);
491 clk_unprepare(pc->tbclk);
493 pm_runtime_disable(&pdev->dev);
495 return pwmchip_remove(&pc->chip);
498 #ifdef CONFIG_PM_SLEEP
499 static void ehrpwm_pwm_save_context(struct ehrpwm_pwm_chip *pc)
501 pm_runtime_get_sync(pc->chip.dev);
503 pc->ctx.tbctl = ehrpwm_read(pc->mmio_base, TBCTL);
504 pc->ctx.tbprd = ehrpwm_read(pc->mmio_base, TBPRD);
505 pc->ctx.cmpa = ehrpwm_read(pc->mmio_base, CMPA);
506 pc->ctx.cmpb = ehrpwm_read(pc->mmio_base, CMPB);
507 pc->ctx.aqctla = ehrpwm_read(pc->mmio_base, AQCTLA);
508 pc->ctx.aqctlb = ehrpwm_read(pc->mmio_base, AQCTLB);
509 pc->ctx.aqsfrc = ehrpwm_read(pc->mmio_base, AQSFRC);
510 pc->ctx.aqcsfrc = ehrpwm_read(pc->mmio_base, AQCSFRC);
512 pm_runtime_put_sync(pc->chip.dev);
515 static void ehrpwm_pwm_restore_context(struct ehrpwm_pwm_chip *pc)
517 ehrpwm_write(pc->mmio_base, TBPRD, pc->ctx.tbprd);
518 ehrpwm_write(pc->mmio_base, CMPA, pc->ctx.cmpa);
519 ehrpwm_write(pc->mmio_base, CMPB, pc->ctx.cmpb);
520 ehrpwm_write(pc->mmio_base, AQCTLA, pc->ctx.aqctla);
521 ehrpwm_write(pc->mmio_base, AQCTLB, pc->ctx.aqctlb);
522 ehrpwm_write(pc->mmio_base, AQSFRC, pc->ctx.aqsfrc);
523 ehrpwm_write(pc->mmio_base, AQCSFRC, pc->ctx.aqcsfrc);
524 ehrpwm_write(pc->mmio_base, TBCTL, pc->ctx.tbctl);
527 static int ehrpwm_pwm_suspend(struct device *dev)
529 struct ehrpwm_pwm_chip *pc = dev_get_drvdata(dev);
530 unsigned int i;
532 ehrpwm_pwm_save_context(pc);
534 for (i = 0; i < pc->chip.npwm; i++) {
535 struct pwm_device *pwm = &pc->chip.pwms[i];
537 if (!pwm_is_enabled(pwm))
538 continue;
540 /* Disable explicitly if PWM is running */
541 pm_runtime_put_sync(dev);
544 return 0;
547 static int ehrpwm_pwm_resume(struct device *dev)
549 struct ehrpwm_pwm_chip *pc = dev_get_drvdata(dev);
550 unsigned int i;
552 for (i = 0; i < pc->chip.npwm; i++) {
553 struct pwm_device *pwm = &pc->chip.pwms[i];
555 if (!pwm_is_enabled(pwm))
556 continue;
558 /* Enable explicitly if PWM was running */
559 pm_runtime_get_sync(dev);
562 ehrpwm_pwm_restore_context(pc);
564 return 0;
566 #endif
568 static SIMPLE_DEV_PM_OPS(ehrpwm_pwm_pm_ops, ehrpwm_pwm_suspend,
569 ehrpwm_pwm_resume);
571 static struct platform_driver ehrpwm_pwm_driver = {
572 .driver = {
573 .name = "ehrpwm",
574 .of_match_table = ehrpwm_of_match,
575 .pm = &ehrpwm_pwm_pm_ops,
577 .probe = ehrpwm_pwm_probe,
578 .remove = ehrpwm_pwm_remove,
580 module_platform_driver(ehrpwm_pwm_driver);
582 MODULE_DESCRIPTION("EHRPWM PWM driver");
583 MODULE_AUTHOR("Texas Instruments");
584 MODULE_LICENSE("GPL");