129 lines
3.7 KiB
C
129 lines
3.7 KiB
C
/* $NetBSD: pwm_fan.c,v 1.1 2018/07/04 23:08:06 jmcneill Exp $ */
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/*-
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* Copyright (c) 2018 Jared McNeill <jmcneill@invisible.ca>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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__KERNEL_RCSID(0, "$NetBSD: pwm_fan.c,v 1.1 2018/07/04 23:08:06 jmcneill Exp $");
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#include <sys/param.h>
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#include <sys/bus.h>
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#include <sys/device.h>
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#include <sys/systm.h>
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#include <sys/sysctl.h>
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#include <sys/kmem.h>
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#include <sys/gpio.h>
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#include <dev/pwm/pwmvar.h>
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#include <dev/fdt/fdtvar.h>
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struct pwm_fan_softc {
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device_t sc_dev;
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pwm_tag_t sc_pwm;
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struct fdtbus_gpio_pin *sc_pin;
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u_int *sc_levels;
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u_int sc_nlevels;
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};
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static int pwm_fan_match(device_t, cfdata_t, void *);
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static void pwm_fan_attach(device_t, device_t, void *);
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static void pwm_fan_set(struct pwm_fan_softc *, u_int);
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static const char *compatible[] = {
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"pwm-fan",
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NULL
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};
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CFATTACH_DECL_NEW(pwmfan, sizeof(struct pwm_fan_softc),
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pwm_fan_match, pwm_fan_attach, NULL, NULL);
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static int
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pwm_fan_match(device_t parent, cfdata_t cf, void *aux)
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{
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struct fdt_attach_args * const faa = aux;
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return of_match_compatible(faa->faa_phandle, compatible);
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}
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static void
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pwm_fan_attach(device_t parent, device_t self, void *aux)
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{
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struct pwm_fan_softc * const sc = device_private(self);
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struct fdt_attach_args * const faa = aux;
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const int phandle = faa->faa_phandle;
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const u_int *levels;
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u_int n;
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int len;
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sc->sc_dev = self;
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sc->sc_pwm = fdtbus_pwm_acquire(phandle, "pwms");
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if (sc->sc_pwm == NULL) {
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aprint_error(": couldn't acquire pwm\n");
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return;
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}
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levels = fdtbus_get_prop(phandle, "cooling-levels", &len);
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if (len < 4) {
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aprint_error(": couldn't get 'cooling-levels' property\n");
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return;
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}
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sc->sc_levels = kmem_alloc(len, KM_SLEEP);
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sc->sc_nlevels = len / 4;
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for (n = 0; n < sc->sc_nlevels; n++)
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sc->sc_levels[n] = be32toh(levels[n]);
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aprint_naive("\n");
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aprint_normal(": PWM Fan");
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aprint_normal(" (levels");
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for (n = 0; n < sc->sc_nlevels; n++) {
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aprint_normal(" %u%%", (sc->sc_levels[n] * 100) / 255);
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}
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aprint_normal(")\n");
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/* Select the highest cooling level */
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pwm_fan_set(sc, 255);
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}
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static void
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pwm_fan_set(struct pwm_fan_softc *sc, u_int level)
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{
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struct pwm_config conf;
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if (level > 255)
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level = 255;
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aprint_debug_dev(sc->sc_dev, "set duty cycle to %u%%\n", (level * 100) / 255);
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pwm_disable(sc->sc_pwm);
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pwm_get_config(sc->sc_pwm, &conf);
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conf.duty_cycle = (conf.period * level) / 255;
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pwm_set_config(sc->sc_pwm, &conf);
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pwm_enable(sc->sc_pwm);
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}
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