xref: /freebsd/sys/arm/ti/am335x/am335x_ehrpwm.c (revision 62cfcf62f627e5093fb37026a6d8c98e4d2ef04c)
1 /*-
2  * Copyright (c) 2013 Oleksandr Tymoshenko <gonzo@freebsd.org>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/bus.h>
33 #include <sys/kernel.h>
34 #include <sys/limits.h>
35 #include <sys/lock.h>
36 #include <sys/module.h>
37 #include <sys/mutex.h>
38 #include <sys/resource.h>
39 #include <sys/rman.h>
40 #include <sys/sysctl.h>
41 
42 #include <machine/bus.h>
43 
44 #include <dev/ofw/openfirm.h>
45 #include <dev/ofw/ofw_bus.h>
46 #include <dev/ofw/ofw_bus_subr.h>
47 
48 #include "pwmbus_if.h"
49 
50 #include "am335x_pwm.h"
51 
52 /*******************************************************************************
53  * Enhanced resolution PWM driver.  Many of the advanced featues of the hardware
54  * are not supported by this driver.  What is implemented here is simple
55  * variable-duty-cycle PWM output.
56  *
57  * Note that this driver was historically configured using a set of sysctl
58  * variables/procs, and later gained support for the PWM(9) API.  The sysctl
59  * code is still present to support existing apps, but that interface is
60  * considered deprecated.
61  *
62  * An important caveat is that the original sysctl interface and the new PWM API
63  * cannot both be used at once.  If both interfaces are used to change
64  * configuration, it's quite likely you won't get the expected results.  Also,
65  * reading the sysctl values after configuring via PWM will not return the right
66  * results.
67  ******************************************************************************/
68 
69 /* In ticks */
70 #define	DEFAULT_PWM_PERIOD	1000
71 #define	PWM_CLOCK		100000000UL
72 
73 #define	NS_PER_SEC		1000000000
74 
75 #define	PWM_LOCK(_sc)		mtx_lock(&(_sc)->sc_mtx)
76 #define	PWM_UNLOCK(_sc)		mtx_unlock(&(_sc)->sc_mtx)
77 #define	PWM_LOCK_ASSERT(_sc)    mtx_assert(&(_sc)->sc_mtx, MA_OWNED)
78 #define	PWM_LOCK_INIT(_sc)	mtx_init(&(_sc)->sc_mtx, \
79     device_get_nameunit(_sc->sc_dev), "am335x_ehrpwm softc", MTX_DEF)
80 #define	PWM_LOCK_DESTROY(_sc)	mtx_destroy(&(_sc)->sc_mtx)
81 
82 #define	EPWM_READ2(_sc, reg)	bus_read_2((_sc)->sc_mem_res, reg)
83 #define	EPWM_WRITE2(_sc, reg, value)	\
84     bus_write_2((_sc)->sc_mem_res, reg, value)
85 
86 #define	EPWM_TBCTL		0x00
87 #define		TBCTL_FREERUN		(2 << 14)
88 #define		TBCTL_PHDIR_UP		(1 << 13)
89 #define		TBCTL_PHDIR_DOWN	(0 << 13)
90 #define		TBCTL_CLKDIV(x)		((x) << 10)
91 #define		TBCTL_CLKDIV_MASK	(3 << 10)
92 #define		TBCTL_HSPCLKDIV(x)	((x) << 7)
93 #define		TBCTL_HSPCLKDIV_MASK	(3 << 7)
94 #define		TBCTL_SYNCOSEL_DISABLED	(3 << 4)
95 #define		TBCTL_PRDLD_SHADOW	(0 << 3)
96 #define		TBCTL_PRDLD_IMMEDIATE	(0 << 3)
97 #define		TBCTL_PHSEN_ENABLED	(1 << 2)
98 #define		TBCTL_PHSEN_DISABLED	(0 << 2)
99 #define		TBCTL_CTRMODE_MASK	(3)
100 #define		TBCTL_CTRMODE_UP	(0 << 0)
101 #define		TBCTL_CTRMODE_DOWN	(1 << 0)
102 #define		TBCTL_CTRMODE_UPDOWN	(2 << 0)
103 #define		TBCTL_CTRMODE_FREEZE	(3 << 0)
104 
105 #define	EPWM_TBSTS		0x02
106 #define	EPWM_TBPHSHR		0x04
107 #define	EPWM_TBPHS		0x06
108 #define	EPWM_TBCNT		0x08
109 #define	EPWM_TBPRD		0x0a
110 /* Counter-compare */
111 #define	EPWM_CMPCTL		0x0e
112 #define		CMPCTL_SHDWBMODE_SHADOW		(1 << 6)
113 #define		CMPCTL_SHDWBMODE_IMMEDIATE	(0 << 6)
114 #define		CMPCTL_SHDWAMODE_SHADOW		(1 << 4)
115 #define		CMPCTL_SHDWAMODE_IMMEDIATE	(0 << 4)
116 #define		CMPCTL_LOADBMODE_ZERO		(0 << 2)
117 #define		CMPCTL_LOADBMODE_PRD		(1 << 2)
118 #define		CMPCTL_LOADBMODE_EITHER		(2 << 2)
119 #define		CMPCTL_LOADBMODE_FREEZE		(3 << 2)
120 #define		CMPCTL_LOADAMODE_ZERO		(0 << 0)
121 #define		CMPCTL_LOADAMODE_PRD		(1 << 0)
122 #define		CMPCTL_LOADAMODE_EITHER		(2 << 0)
123 #define		CMPCTL_LOADAMODE_FREEZE		(3 << 0)
124 #define	EPWM_CMPAHR		0x10
125 #define	EPWM_CMPA		0x12
126 #define	EPWM_CMPB		0x14
127 /* CMPCTL_LOADAMODE_ZERO */
128 #define	EPWM_AQCTLA		0x16
129 #define	EPWM_AQCTLB		0x18
130 #define		AQCTL_CBU_NONE		(0 << 8)
131 #define		AQCTL_CBU_CLEAR		(1 << 8)
132 #define		AQCTL_CBU_SET		(2 << 8)
133 #define		AQCTL_CBU_TOGGLE	(3 << 8)
134 #define		AQCTL_CAU_NONE		(0 << 4)
135 #define		AQCTL_CAU_CLEAR		(1 << 4)
136 #define		AQCTL_CAU_SET		(2 << 4)
137 #define		AQCTL_CAU_TOGGLE	(3 << 4)
138 #define		AQCTL_ZRO_NONE		(0 << 0)
139 #define		AQCTL_ZRO_CLEAR		(1 << 0)
140 #define		AQCTL_ZRO_SET		(2 << 0)
141 #define		AQCTL_ZRO_TOGGLE	(3 << 0)
142 #define	EPWM_AQSFRC		0x1a
143 #define	EPWM_AQCSFRC		0x1c
144 #define		AQCSFRC_OFF		0
145 #define		AQCSFRC_LO		1
146 #define		AQCSFRC_HI		2
147 #define		AQCSFRC_MASK		3
148 #define		AQCSFRC(chan, hilo)	((hilo) << (2 * chan))
149 
150 /* Trip-Zone module */
151 #define	EPWM_TZCTL		0x28
152 #define	EPWM_TZFLG		0x2C
153 /* High-Resolution PWM */
154 #define	EPWM_HRCTL		0x40
155 #define		HRCTL_DELMODE_BOTH	3
156 #define		HRCTL_DELMODE_FALL	2
157 #define		HRCTL_DELMODE_RISE	1
158 
159 static device_probe_t am335x_ehrpwm_probe;
160 static device_attach_t am335x_ehrpwm_attach;
161 static device_detach_t am335x_ehrpwm_detach;
162 
163 static int am335x_ehrpwm_clkdiv[8] = { 1, 2, 4, 8, 16, 32, 64, 128 };
164 
165 struct ehrpwm_channel {
166 	u_int	duty;		/* on duration, in ns */
167 	bool	enabled;	/* channel enabled? */
168 	bool	inverted;	/* signal inverted? */
169 };
170 #define	NUM_CHANNELS	2
171 
172 struct am335x_ehrpwm_softc {
173 	device_t		sc_dev;
174 	device_t		sc_busdev;
175 	struct mtx		sc_mtx;
176 	struct resource		*sc_mem_res;
177 	int			sc_mem_rid;
178 
179 	/* Things used for configuration via sysctl [deprecated]. */
180 	int			sc_pwm_clkdiv;
181 	int			sc_pwm_freq;
182 	struct sysctl_oid	*sc_clkdiv_oid;
183 	struct sysctl_oid	*sc_freq_oid;
184 	struct sysctl_oid	*sc_period_oid;
185 	struct sysctl_oid	*sc_chanA_oid;
186 	struct sysctl_oid	*sc_chanB_oid;
187 	uint32_t		sc_pwm_period;
188 	uint32_t		sc_pwm_dutyA;
189 	uint32_t		sc_pwm_dutyB;
190 
191 	/* Things used for configuration via pwm(9) api. */
192 	u_int			sc_clkfreq; /* frequency in Hz */
193 	u_int			sc_clktick; /* duration in ns */
194 	u_int			sc_period;  /* duration in ns */
195 	struct ehrpwm_channel	sc_channels[NUM_CHANNELS];
196 };
197 
198 static struct ofw_compat_data compat_data[] = {
199 	{"ti,am33xx-ehrpwm",    true},
200 	{NULL,                  false},
201 };
202 SIMPLEBUS_PNP_INFO(compat_data);
203 
204 static void
205 am335x_ehrpwm_cfg_duty(struct am335x_ehrpwm_softc *sc, u_int chan, u_int duty)
206 {
207 	u_int tbcmp;
208 
209 	if (duty == 0)
210 		tbcmp = 0;
211 	else
212 		tbcmp = max(1, duty / sc->sc_clktick);
213 
214 	sc->sc_channels[chan].duty = tbcmp * sc->sc_clktick;
215 
216 	PWM_LOCK_ASSERT(sc);
217 	EPWM_WRITE2(sc, (chan == 0) ? EPWM_CMPA : EPWM_CMPB, tbcmp);
218 }
219 
220 static void
221 am335x_ehrpwm_cfg_enable(struct am335x_ehrpwm_softc *sc, u_int chan, bool enable)
222 {
223 	uint16_t regval;
224 
225 	sc->sc_channels[chan].enabled = enable;
226 
227 	/*
228 	 * Turn off any existing software-force of the channel, then force
229 	 * it in the right direction (high or low) if it's not being enabled.
230 	 */
231 	PWM_LOCK_ASSERT(sc);
232 	regval = EPWM_READ2(sc, EPWM_AQCSFRC);
233 	regval &= ~AQCSFRC(chan, AQCSFRC_MASK);
234 	if (!sc->sc_channels[chan].enabled) {
235 		if (sc->sc_channels[chan].inverted)
236 			regval |= AQCSFRC(chan, AQCSFRC_HI);
237 		else
238 			regval |= AQCSFRC(chan, AQCSFRC_LO);
239 	}
240 	EPWM_WRITE2(sc, EPWM_AQCSFRC, regval);
241 }
242 
243 static bool
244 am335x_ehrpwm_cfg_period(struct am335x_ehrpwm_softc *sc, u_int period)
245 {
246 	uint16_t regval;
247 	u_int clkdiv, hspclkdiv, pwmclk, pwmtick, tbprd;
248 
249 	/* Can't do a period shorter than 2 clock ticks. */
250 	if (period < 2 * NS_PER_SEC / PWM_CLOCK) {
251 		sc->sc_clkfreq = 0;
252 		sc->sc_clktick = 0;
253 		sc->sc_period  = 0;
254 		return (false);
255 	}
256 
257 	/*
258 	 * Figure out how much we have to divide down the base 100MHz clock so
259 	 * that we can express the requested period as a 16-bit tick count.
260 	 */
261 	tbprd = 0;
262 	for (clkdiv = 0; clkdiv < 8; ++clkdiv) {
263 		const u_int cd = 1 << clkdiv;
264 		for (hspclkdiv = 0; hspclkdiv < 8; ++hspclkdiv) {
265 			const u_int cdhs = max(1, hspclkdiv * 2);
266 			pwmclk = PWM_CLOCK / (cd * cdhs);
267 			pwmtick = NS_PER_SEC / pwmclk;
268 			if (period / pwmtick < 65536) {
269 				tbprd = period / pwmtick;
270 				break;
271 			}
272 		}
273 		if (tbprd != 0)
274 			break;
275 	}
276 
277 	/* Handle requested period too long for available clock divisors. */
278 	if (tbprd == 0)
279 		return (false);
280 
281 	/*
282 	 * If anything has changed from the current settings, reprogram the
283 	 * clock divisors and period register.
284 	 */
285 	if (sc->sc_clkfreq != pwmclk || sc->sc_clktick != pwmtick ||
286 	    sc->sc_period != tbprd * pwmtick) {
287 
288 		sc->sc_clkfreq = pwmclk;
289 		sc->sc_clktick = pwmtick;
290 		sc->sc_period  = tbprd * pwmtick;
291 
292 		PWM_LOCK_ASSERT(sc);
293 		regval = EPWM_READ2(sc, EPWM_TBCTL);
294 		regval &= ~(TBCTL_CLKDIV_MASK | TBCTL_HSPCLKDIV_MASK);
295 		regval |= TBCTL_CLKDIV(clkdiv) | TBCTL_HSPCLKDIV(hspclkdiv);
296 		EPWM_WRITE2(sc, EPWM_TBCTL, regval);
297 		EPWM_WRITE2(sc, EPWM_TBPRD, tbprd - 1);
298 #if 0
299 		device_printf(sc->sc_dev, "clkdiv %u hspclkdiv %u tbprd %u "
300 		    "clkfreq %u Hz clktick %u ns period got %u requested %u\n",
301 		    clkdiv, hspclkdiv, tbprd - 1,
302 		    sc->sc_clkfreq, sc->sc_clktick, sc->sc_period, period);
303 #endif
304 		/*
305 		 * If the period changed, that invalidates the current CMP
306 		 * registers (duty values), just zero them out.
307 		 */
308 		am335x_ehrpwm_cfg_duty(sc, 0, 0);
309 		am335x_ehrpwm_cfg_duty(sc, 1, 0);
310 	}
311 
312 	return (true);
313 }
314 
315 static void
316 am335x_ehrpwm_freq(struct am335x_ehrpwm_softc *sc)
317 {
318 	int clkdiv;
319 
320 	clkdiv = am335x_ehrpwm_clkdiv[sc->sc_pwm_clkdiv];
321 	sc->sc_pwm_freq = PWM_CLOCK / (1 * clkdiv) / sc->sc_pwm_period;
322 }
323 
324 static int
325 am335x_ehrpwm_sysctl_freq(SYSCTL_HANDLER_ARGS)
326 {
327 	int clkdiv, error, freq, i, period;
328 	struct am335x_ehrpwm_softc *sc;
329 	uint32_t reg;
330 
331 	sc = (struct am335x_ehrpwm_softc *)arg1;
332 
333 	PWM_LOCK(sc);
334 	freq = sc->sc_pwm_freq;
335 	PWM_UNLOCK(sc);
336 
337 	error = sysctl_handle_int(oidp, &freq, sizeof(freq), req);
338 	if (error != 0 || req->newptr == NULL)
339 		return (error);
340 
341 	if (freq > PWM_CLOCK)
342 		freq = PWM_CLOCK;
343 
344 	PWM_LOCK(sc);
345 	if (freq != sc->sc_pwm_freq) {
346 		for (i = nitems(am335x_ehrpwm_clkdiv) - 1; i >= 0; i--) {
347 			clkdiv = am335x_ehrpwm_clkdiv[i];
348 			period = PWM_CLOCK / clkdiv / freq;
349 			if (period > USHRT_MAX)
350 				break;
351 			sc->sc_pwm_clkdiv = i;
352 			sc->sc_pwm_period = period;
353 		}
354 		/* Reset the duty cycle settings. */
355 		sc->sc_pwm_dutyA = 0;
356 		sc->sc_pwm_dutyB = 0;
357 		EPWM_WRITE2(sc, EPWM_CMPA, sc->sc_pwm_dutyA);
358 		EPWM_WRITE2(sc, EPWM_CMPB, sc->sc_pwm_dutyB);
359 		/* Update the clkdiv settings. */
360 		reg = EPWM_READ2(sc, EPWM_TBCTL);
361 		reg &= ~TBCTL_CLKDIV_MASK;
362 		reg |= TBCTL_CLKDIV(sc->sc_pwm_clkdiv);
363 		EPWM_WRITE2(sc, EPWM_TBCTL, reg);
364 		/* Update the period settings. */
365 		EPWM_WRITE2(sc, EPWM_TBPRD, sc->sc_pwm_period - 1);
366 		am335x_ehrpwm_freq(sc);
367 	}
368 	PWM_UNLOCK(sc);
369 
370 	return (0);
371 }
372 
373 static int
374 am335x_ehrpwm_sysctl_clkdiv(SYSCTL_HANDLER_ARGS)
375 {
376 	int error, i, clkdiv;
377 	struct am335x_ehrpwm_softc *sc;
378 	uint32_t reg;
379 
380 	sc = (struct am335x_ehrpwm_softc *)arg1;
381 
382 	PWM_LOCK(sc);
383 	clkdiv = am335x_ehrpwm_clkdiv[sc->sc_pwm_clkdiv];
384 	PWM_UNLOCK(sc);
385 
386 	error = sysctl_handle_int(oidp, &clkdiv, sizeof(clkdiv), req);
387 	if (error != 0 || req->newptr == NULL)
388 		return (error);
389 
390 	PWM_LOCK(sc);
391 	if (clkdiv != am335x_ehrpwm_clkdiv[sc->sc_pwm_clkdiv]) {
392 		for (i = 0; i < nitems(am335x_ehrpwm_clkdiv); i++)
393 			if (clkdiv >= am335x_ehrpwm_clkdiv[i])
394 				sc->sc_pwm_clkdiv = i;
395 
396 		reg = EPWM_READ2(sc, EPWM_TBCTL);
397 		reg &= ~TBCTL_CLKDIV_MASK;
398 		reg |= TBCTL_CLKDIV(sc->sc_pwm_clkdiv);
399 		EPWM_WRITE2(sc, EPWM_TBCTL, reg);
400 		am335x_ehrpwm_freq(sc);
401 	}
402 	PWM_UNLOCK(sc);
403 
404 	return (0);
405 }
406 
407 static int
408 am335x_ehrpwm_sysctl_duty(SYSCTL_HANDLER_ARGS)
409 {
410 	struct am335x_ehrpwm_softc *sc = (struct am335x_ehrpwm_softc*)arg1;
411 	int error;
412 	uint32_t duty;
413 
414 	if (oidp == sc->sc_chanA_oid)
415 		duty = sc->sc_pwm_dutyA;
416 	else
417 		duty = sc->sc_pwm_dutyB;
418 	error = sysctl_handle_int(oidp, &duty, 0, req);
419 
420 	if (error != 0 || req->newptr == NULL)
421 		return (error);
422 
423 	if (duty > sc->sc_pwm_period) {
424 		device_printf(sc->sc_dev, "Duty cycle can't be greater then period\n");
425 		return (EINVAL);
426 	}
427 
428 	PWM_LOCK(sc);
429 	if (oidp == sc->sc_chanA_oid) {
430 		sc->sc_pwm_dutyA = duty;
431 		EPWM_WRITE2(sc, EPWM_CMPA, sc->sc_pwm_dutyA);
432 	}
433 	else {
434 		sc->sc_pwm_dutyB = duty;
435 		EPWM_WRITE2(sc, EPWM_CMPB, sc->sc_pwm_dutyB);
436 	}
437 	PWM_UNLOCK(sc);
438 
439 	return (error);
440 }
441 
442 static int
443 am335x_ehrpwm_sysctl_period(SYSCTL_HANDLER_ARGS)
444 {
445 	struct am335x_ehrpwm_softc *sc = (struct am335x_ehrpwm_softc*)arg1;
446 	int error;
447 	uint32_t period;
448 
449 	period = sc->sc_pwm_period;
450 	error = sysctl_handle_int(oidp, &period, 0, req);
451 
452 	if (error != 0 || req->newptr == NULL)
453 		return (error);
454 
455 	if (period < 1)
456 		return (EINVAL);
457 
458 	if (period > USHRT_MAX)
459 		period = USHRT_MAX;
460 
461 	PWM_LOCK(sc);
462 	/* Reset the duty cycle settings. */
463 	sc->sc_pwm_dutyA = 0;
464 	sc->sc_pwm_dutyB = 0;
465 	EPWM_WRITE2(sc, EPWM_CMPA, sc->sc_pwm_dutyA);
466 	EPWM_WRITE2(sc, EPWM_CMPB, sc->sc_pwm_dutyB);
467 	/* Update the period settings. */
468 	sc->sc_pwm_period = period;
469 	EPWM_WRITE2(sc, EPWM_TBPRD, period - 1);
470 	am335x_ehrpwm_freq(sc);
471 	PWM_UNLOCK(sc);
472 
473 	return (error);
474 }
475 
476 static int
477 am335x_ehrpwm_channel_count(device_t dev, u_int *nchannel)
478 {
479 
480 	*nchannel = NUM_CHANNELS;
481 
482 	return (0);
483 }
484 
485 static int
486 am335x_ehrpwm_channel_config(device_t dev, u_int channel, u_int period, u_int duty)
487 {
488 	struct am335x_ehrpwm_softc *sc;
489 	bool status;
490 
491 	if (channel >= NUM_CHANNELS)
492 		return (EINVAL);
493 
494 	sc = device_get_softc(dev);
495 
496 	PWM_LOCK(sc);
497 	status = am335x_ehrpwm_cfg_period(sc, period);
498 	if (status)
499 		am335x_ehrpwm_cfg_duty(sc, channel, duty);
500 	PWM_UNLOCK(sc);
501 
502 	return (status ? 0 : EINVAL);
503 }
504 
505 static int
506 am335x_ehrpwm_channel_get_config(device_t dev, u_int channel,
507     u_int *period, u_int *duty)
508 {
509 	struct am335x_ehrpwm_softc *sc;
510 
511 	if (channel >= NUM_CHANNELS)
512 		return (EINVAL);
513 
514 	sc = device_get_softc(dev);
515 	*period = sc->sc_period;
516 	*duty = sc->sc_channels[channel].duty;
517 	return (0);
518 }
519 
520 static int
521 am335x_ehrpwm_channel_enable(device_t dev, u_int channel, bool enable)
522 {
523 	struct am335x_ehrpwm_softc *sc;
524 
525 	if (channel >= NUM_CHANNELS)
526 		return (EINVAL);
527 
528 	sc = device_get_softc(dev);
529 
530 	PWM_LOCK(sc);
531 	am335x_ehrpwm_cfg_enable(sc, channel, enable);
532 	PWM_UNLOCK(sc);
533 
534 	return (0);
535 }
536 
537 static int
538 am335x_ehrpwm_channel_is_enabled(device_t dev, u_int channel, bool *enabled)
539 {
540 	struct am335x_ehrpwm_softc *sc;
541 
542 	if (channel >= NUM_CHANNELS)
543 		return (EINVAL);
544 
545 	sc = device_get_softc(dev);
546 
547 	*enabled = sc->sc_channels[channel].enabled;
548 
549 	return (0);
550 }
551 
552 static int
553 am335x_ehrpwm_probe(device_t dev)
554 {
555 
556 	if (!ofw_bus_status_okay(dev))
557 		return (ENXIO);
558 
559 	if (!ofw_bus_search_compatible(dev, compat_data)->ocd_data)
560 		return (ENXIO);
561 
562 	device_set_desc(dev, "AM335x EHRPWM");
563 
564 	return (BUS_PROBE_DEFAULT);
565 }
566 
567 static int
568 am335x_ehrpwm_attach(device_t dev)
569 {
570 	struct am335x_ehrpwm_softc *sc;
571 	uint32_t reg;
572 	struct sysctl_ctx_list *ctx;
573 	struct sysctl_oid *tree;
574 
575 	sc = device_get_softc(dev);
576 	sc->sc_dev = dev;
577 
578 	PWM_LOCK_INIT(sc);
579 
580 	sc->sc_mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY,
581 	    &sc->sc_mem_rid, RF_ACTIVE);
582 	if (sc->sc_mem_res == NULL) {
583 		device_printf(dev, "cannot allocate memory resources\n");
584 		goto fail;
585 	}
586 
587 	/* Init sysctl interface */
588 	ctx = device_get_sysctl_ctx(sc->sc_dev);
589 	tree = device_get_sysctl_tree(sc->sc_dev);
590 
591 	sc->sc_clkdiv_oid = SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
592 	    "clkdiv", CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, sc, 0,
593 	    am335x_ehrpwm_sysctl_clkdiv, "I", "PWM clock prescaler");
594 
595 	sc->sc_freq_oid = SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
596 	    "freq", CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, sc, 0,
597 	    am335x_ehrpwm_sysctl_freq, "I", "PWM frequency");
598 
599 	sc->sc_period_oid = SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
600 	    "period", CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, sc, 0,
601 	    am335x_ehrpwm_sysctl_period, "I", "PWM period");
602 
603 	sc->sc_chanA_oid = SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
604 	    "dutyA", CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, sc, 0,
605 	    am335x_ehrpwm_sysctl_duty, "I", "Channel A duty cycles");
606 
607 	sc->sc_chanB_oid = SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
608 	    "dutyB", CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, sc, 0,
609 	    am335x_ehrpwm_sysctl_duty, "I", "Channel B duty cycles");
610 
611 	/* CONFIGURE EPWM1 */
612 	reg = EPWM_READ2(sc, EPWM_TBCTL);
613 	reg &= ~(TBCTL_CLKDIV_MASK | TBCTL_HSPCLKDIV_MASK);
614 	EPWM_WRITE2(sc, EPWM_TBCTL, reg);
615 
616 	sc->sc_pwm_period = DEFAULT_PWM_PERIOD;
617 	sc->sc_pwm_dutyA = 0;
618 	sc->sc_pwm_dutyB = 0;
619 	am335x_ehrpwm_freq(sc);
620 
621 	EPWM_WRITE2(sc, EPWM_TBPRD, sc->sc_pwm_period - 1);
622 	EPWM_WRITE2(sc, EPWM_CMPA, sc->sc_pwm_dutyA);
623 	EPWM_WRITE2(sc, EPWM_CMPB, sc->sc_pwm_dutyB);
624 
625 	EPWM_WRITE2(sc, EPWM_AQCTLA, (AQCTL_ZRO_SET | AQCTL_CAU_CLEAR));
626 	EPWM_WRITE2(sc, EPWM_AQCTLB, (AQCTL_ZRO_SET | AQCTL_CBU_CLEAR));
627 
628 	/* START EPWM */
629 	reg &= ~TBCTL_CTRMODE_MASK;
630 	reg |= TBCTL_CTRMODE_UP | TBCTL_FREERUN;
631 	EPWM_WRITE2(sc, EPWM_TBCTL, reg);
632 
633 	EPWM_WRITE2(sc, EPWM_TZCTL, 0xf);
634 	reg = EPWM_READ2(sc, EPWM_TZFLG);
635 
636 	if ((sc->sc_busdev = device_add_child(dev, "pwmbus", -1)) == NULL) {
637 		device_printf(dev, "Cannot add child pwmbus\n");
638 		// This driver can still do things even without the bus child.
639 	}
640 
641 	bus_generic_probe(dev);
642 	return (bus_generic_attach(dev));
643 fail:
644 	PWM_LOCK_DESTROY(sc);
645 	if (sc->sc_mem_res)
646 		bus_release_resource(dev, SYS_RES_MEMORY,
647 		    sc->sc_mem_rid, sc->sc_mem_res);
648 
649 	return(ENXIO);
650 }
651 
652 static int
653 am335x_ehrpwm_detach(device_t dev)
654 {
655 	struct am335x_ehrpwm_softc *sc;
656 	int error;
657 
658 	sc = device_get_softc(dev);
659 
660 	if ((error = bus_generic_detach(sc->sc_dev)) != 0)
661 		return (error);
662 
663 	PWM_LOCK(sc);
664 
665 	if (sc->sc_busdev != NULL)
666 		device_delete_child(dev, sc->sc_busdev);
667 
668 	if (sc->sc_mem_res)
669 		bus_release_resource(dev, SYS_RES_MEMORY,
670 		    sc->sc_mem_rid, sc->sc_mem_res);
671 
672 	PWM_UNLOCK(sc);
673 
674 	PWM_LOCK_DESTROY(sc);
675 
676 	return (0);
677 }
678 
679 static phandle_t
680 am335x_ehrpwm_get_node(device_t bus, device_t dev)
681 {
682 
683 	/*
684 	 * Share our controller node with our pwmbus child; it instantiates
685 	 * devices by walking the children contained within our node.
686 	 */
687 	return ofw_bus_get_node(bus);
688 }
689 
690 static device_method_t am335x_ehrpwm_methods[] = {
691 	DEVMETHOD(device_probe,		am335x_ehrpwm_probe),
692 	DEVMETHOD(device_attach,	am335x_ehrpwm_attach),
693 	DEVMETHOD(device_detach,	am335x_ehrpwm_detach),
694 
695 	/* ofw_bus_if */
696 	DEVMETHOD(ofw_bus_get_node,	am335x_ehrpwm_get_node),
697 
698 	/* pwm interface */
699 	DEVMETHOD(pwmbus_channel_count,		am335x_ehrpwm_channel_count),
700 	DEVMETHOD(pwmbus_channel_config,	am335x_ehrpwm_channel_config),
701 	DEVMETHOD(pwmbus_channel_get_config,	am335x_ehrpwm_channel_get_config),
702 	DEVMETHOD(pwmbus_channel_enable,	am335x_ehrpwm_channel_enable),
703 	DEVMETHOD(pwmbus_channel_is_enabled,	am335x_ehrpwm_channel_is_enabled),
704 
705 	DEVMETHOD_END
706 };
707 
708 static driver_t am335x_ehrpwm_driver = {
709 	"pwm",
710 	am335x_ehrpwm_methods,
711 	sizeof(struct am335x_ehrpwm_softc),
712 };
713 
714 static devclass_t am335x_ehrpwm_devclass;
715 
716 DRIVER_MODULE(am335x_ehrpwm, am335x_pwmss, am335x_ehrpwm_driver, am335x_ehrpwm_devclass, 0, 0);
717 MODULE_VERSION(am335x_ehrpwm, 1);
718 MODULE_DEPEND(am335x_ehrpwm, am335x_pwmss, 1, 1, 1);
719 MODULE_DEPEND(am335x_ehrpwm, pwmbus, 1, 1, 1);
720