1 // SPDX-License-Identifier: GPL-2.0-or-later
5 * Copyright (C) 2012 Texas Instruments, Inc. - https://www.ti.com/
8 #include <linux/module.h>
9 #include <linux/platform_device.h>
10 #include <linux/pwm.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 */
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) | \
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
38 #define HSPCLKDIV_MAX 7
39 #define PERIOD_MAX 0xFFFF
41 /* compare module registers */
45 /* Action qualifier module registers */
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 | \
70 #define AQCTL_CHANA_POLINVERSED (AQCTL_CAU_FRCHIGH | AQCTL_PRD_FRCLOW | \
72 #define AQCTL_CHANB_POLNORMAL (AQCTL_CBU_FRCLOW | AQCTL_PRD_FRCHIGH | \
74 #define AQCTL_CHANB_POLINVERSED (AQCTL_CBU_FRCHIGH | AQCTL_PRD_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
{
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
];
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
,
130 writew(value
, base
+ offset
);
133 static void ehrpwm_modify(void __iomem
*base
, unsigned int offset
, u16 mask
,
138 val
= readw(base
+ offset
);
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
,
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
);
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
194 aqctl_mask
= AQCTL_CBU_MASK
;
196 if (pc
->polarity
[chan
] == PWM_POLARITY_INVERSED
)
197 aqctl_val
= AQCTL_CHANB_POLINVERSED
;
199 aqctl_val
= AQCTL_CHANB_POLNORMAL
;
202 aqctl_mask
= AQCTL_CAU_MASK
;
204 if (pc
->polarity
[chan
] == PWM_POLARITY_INVERSED
)
205 aqctl_val
= AQCTL_CHANA_POLINVERSED
;
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
)
232 do_div(c
, NSEC_PER_SEC
);
233 period_cycles
= (unsigned long)c
;
235 if (period_cycles
< 1) {
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.
260 "period value conflicts with channel %u\n",
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
,
271 dev_err(chip
->dev
, "Unsupported values\n");
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
,
294 /* Channel 1 configured with compare B register */
297 /* Channel 0 configured with compare A register */
300 ehrpwm_write(pc
->mmio_base
, cmp_reg
, duty_cycles
);
302 pm_runtime_put_sync(chip
->dev
);
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
;
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
;
325 /* Leave clock enabled on enabling PWM */
326 pm_runtime_get_sync(chip
->dev
);
328 /* Disabling Action Qualifier on PWM output */
330 aqcsfrc_val
= AQCSFRC_CSFB_FRCDIS
;
331 aqcsfrc_mask
= AQCSFRC_CSFB_MASK
;
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
,
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
);
347 ret
= clk_enable(pc
->tbclk
);
349 dev_err(chip
->dev
, "Failed to enable TBCLK for %s: %d\n",
350 dev_name(pc
->chip
.dev
), ret
);
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 */
364 aqcsfrc_val
= AQCSFRC_CSFB_FRCLOW
;
365 aqcsfrc_mask
= AQCSFRC_CSFB_MASK
;
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
,
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
,
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
;
427 pc
= devm_kzalloc(&pdev
->dev
, sizeof(*pc
), GFP_KERNEL
);
431 clk
= devm_clk_get(&pdev
->dev
, "fck");
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");
440 return dev_err_probe(&pdev
->dev
, PTR_ERR(clk
), "Failed to get fck\n");
442 pc
->clk_rate
= clk_get_rate(clk
);
444 dev_err(&pdev
->dev
, "failed to get clock rate\n");
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;
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
);
466 dev_err(&pdev
->dev
, "clk_prepare() failed: %d\n", ret
);
470 ret
= pwmchip_add(&pc
->chip
);
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
);
482 clk_unprepare(pc
->tbclk
);
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
);
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
))
540 /* Disable explicitly if PWM is running */
541 pm_runtime_put_sync(dev
);
547 static int ehrpwm_pwm_resume(struct device
*dev
)
549 struct ehrpwm_pwm_chip
*pc
= dev_get_drvdata(dev
);
552 for (i
= 0; i
< pc
->chip
.npwm
; i
++) {
553 struct pwm_device
*pwm
= &pc
->chip
.pwms
[i
];
555 if (!pwm_is_enabled(pwm
))
558 /* Enable explicitly if PWM was running */
559 pm_runtime_get_sync(dev
);
562 ehrpwm_pwm_restore_context(pc
);
568 static SIMPLE_DEV_PM_OPS(ehrpwm_pwm_pm_ops
, ehrpwm_pwm_suspend
,
571 static struct platform_driver ehrpwm_pwm_driver
= {
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");