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imxpwm.c revision 1.1.6.2 
      1 /*	$NetBSD: imxpwm.c,v 1.1.6.2 2014/08/10 06:53:51 tls Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 2014  Genetec Corporation.  All rights reserved.
      5  * Written by Hashimoto Kenichi for Genetec Corporation.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY GENETEC CORPORATION ``AS IS'' AND
     17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     18  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     19  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL GENETEC CORPORATION
     20  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     26  * POSSIBILITY OF SUCH DAMAGE.
     27  */
     28 
     29 #include <sys/cdefs.h>
     30 __KERNEL_RCSID(0, "$NetBSD: imxpwm.c,v 1.1.6.2 2014/08/10 06:53:51 tls Exp $");
     31 
     32 #include "opt_imx.h"
     33 #include "locators.h"
     34 
     35 #include <sys/types.h>
     36 #include <sys/param.h>
     37 #include <sys/bus.h>
     38 #include <sys/device.h>
     39 
     40 #include <arm/imx/imxpwmreg.h>
     41 #include <arm/imx/imxpwmvar.h>
     42 
     43 static inline uint32_t
     44 imxpwm_read(struct imxpwm_softc *sc, bus_size_t o)
     45 {
     46 	return bus_space_read_4(sc->sc_iot, sc->sc_ioh, o);
     47 }
     48 
     49 static inline void
     50 imxpwm_write(struct imxpwm_softc *sc, bus_size_t o, uint32_t v)
     51 {
     52 	bus_space_write_4(sc->sc_iot, sc->sc_ioh, o, v);
     53 }
     54 
     55 static int
     56 imxpwm_intr(void *arg)
     57 {
     58 	struct imxpwm_softc *sc = arg;
     59 	uint32_t sts = imxpwm_read(sc, PWM_SR);
     60 
     61 	imxpwm_write(sc, PWM_SR, sts);
     62 
     63 	if ((sts & SR_ROV) && (sc->sc_handler != NULL))
     64 		sc->sc_handler(sc->sc_cookie);
     65 
     66 	return 1;
     67 }
     68 
     69 void
     70 imxpwm_attach_common(struct imxpwm_softc *sc)
     71 {
     72 	uint32_t reg;
     73 	int div;
     74 
     75 	if (sc->sc_handler != NULL) {
     76 		sc->sc_ih = intr_establish(sc->sc_intr, IPL_BIO, IST_LEVEL,
     77 		    imxpwm_intr, sc);
     78 
     79 		reg = IR_RIE;
     80 		imxpwm_write(sc, PWM_IR, reg);
     81 	}
     82 
     83 	if (sc->sc_hz <= 0)
     84 		sc->sc_hz = IMXPWM_DEFAULT_HZ;
     85 	div = 0;
     86 	do {
     87 		div++;
     88 		sc->sc_cycle = sc->sc_freq / div / sc->sc_hz;
     89 	} while (sc->sc_cycle > 0xffff);
     90 
     91 	imxpwm_write(sc, PWM_PR, __SHIFTIN(sc->sc_cycle - 2, PR_PERIOD));
     92 
     93 	reg = 0;
     94 	reg |= __SHIFTIN(CLKSRC_IPG_CLK, CR_CLKSRC);
     95 	reg |= __SHIFTIN(div - 1, CR_PRESCALER);
     96 	reg |= CR_EN;
     97 	imxpwm_write(sc, PWM_CR, reg);
     98 }
     99 
    100 int
    101 imxpwm_set_pwm(struct imxpwm_softc *sc, int duty)
    102 {
    103 	if (duty < 0 || IMXPWM_DUTY_MAX < duty)
    104 		return EINVAL;
    105 
    106 	sc->sc_duty = duty;
    107 
    108 	uint16_t reg = sc->sc_cycle * sc->sc_duty / IMXPWM_DUTY_MAX;
    109 	if (reg != 0)
    110 		reg -= 1;
    111 	imxpwm_write(sc, PWM_SAR, __SHIFTIN(reg, SAR_SAMPLE));
    112 
    113 	return 0;
    114 }
    115