/* $NetBSD: gpiopwm.c,v 1.6 2017/01/20 12:25:07 maya Exp $ */ /* * Copyright (c) 2011 Marc Balmer * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ /* * Driver for pulsing GPIO pins in software */ #include #include #include #include #include #define GPIOPWM_NPINS 1 struct gpiopwm_softc { device_t sc_dev; void *sc_gpio; struct gpio_pinmap sc_map; int _map[GPIOPWM_NPINS]; callout_t sc_pulse; int sc_ticks_on; int sc_ticks_off; struct sysctllog *sc_log; int sc_dying; }; int gpiopwm_match(device_t, cfdata_t, void *); void gpiopwm_attach(device_t, device_t, void *); int gpiopwm_detach(device_t, int); int gpiopwm_activate(device_t, enum devact); static int gpiopwm_set_on(SYSCTLFN_ARGS); static int gpiopwm_set_off(SYSCTLFN_ARGS); static void gpiopwm_pulse(void *); CFATTACH_DECL_NEW(gpiopwm, sizeof(struct gpiopwm_softc), gpiopwm_match, gpiopwm_attach, gpiopwm_detach, gpiopwm_activate); extern struct cfdriver gpiopwm_cd; int gpiopwm_match(device_t parent, cfdata_t cf, void *aux) { struct gpio_attach_args *ga = aux; if (strcmp(ga->ga_dvname, cf->cf_name)) return 0; if (ga->ga_offset == -1) return 0; /* Check number of pins, must be 1 */ if (gpio_npins(ga->ga_mask) != GPIOPWM_NPINS) { aprint_debug("%s: invalid pin mask 0x%02x\n", cf->cf_name, ga->ga_mask); return 0; } return 1; } void gpiopwm_attach(device_t parent, device_t self, void *aux) { struct gpiopwm_softc *sc = device_private(self); struct gpio_attach_args *ga = aux; const struct sysctlnode *node; sc->sc_dev = self; /* Map pin */ sc->sc_gpio = ga->ga_gpio; sc->sc_map.pm_map = sc->_map; if (gpio_pin_map(sc->sc_gpio, ga->ga_offset, ga->ga_mask, &sc->sc_map)) { aprint_error(": can't map pin\n"); return; } aprint_normal(" [%d]", sc->sc_map.pm_map[0]); if (!pmf_device_register(self, NULL, NULL)) aprint_error_dev(self, "couldn't establish power handler\n"); callout_init(&sc->sc_pulse, CALLOUT_MPSAFE); callout_setfunc(&sc->sc_pulse, gpiopwm_pulse, sc); sysctl_createv(&sc->sc_log, 0, NULL, &node, 0, CTLTYPE_NODE, device_xname(sc->sc_dev), SYSCTL_DESCR("GPIO software PWM"), NULL, 0, NULL, 0, CTL_HW, CTL_CREATE, CTL_EOL); if (node == NULL) { aprint_error(": can't create sysctl node\n"); return; } sysctl_createv(&sc->sc_log, 0, &node, NULL, CTLFLAG_READWRITE, CTLTYPE_INT, "on", SYSCTL_DESCR("PWM 'on' period in ticks"), gpiopwm_set_on, 0, (void *)sc, 0, CTL_CREATE, CTL_EOL); sysctl_createv(&sc->sc_log, 0, &node, NULL, CTLFLAG_READWRITE, CTLTYPE_INT, "off", SYSCTL_DESCR("PWM 'off' period in ticks"), gpiopwm_set_off, 0, (void *)sc, 0, CTL_CREATE, CTL_EOL); aprint_normal("\n"); return; } int gpiopwm_detach(device_t self, int flags) { struct gpiopwm_softc *sc = device_private(self); callout_halt(&sc->sc_pulse, NULL); callout_destroy(&sc->sc_pulse); gpio_pin_write(sc->sc_gpio, &sc->sc_map, 0, GPIO_PIN_LOW); pmf_device_deregister(self); gpio_pin_unmap(sc->sc_gpio, &sc->sc_map); if (sc->sc_log != NULL) { sysctl_teardown(&sc->sc_log); sc->sc_log = NULL; } return 0; } static int gpiopwm_set_on(SYSCTLFN_ARGS) { struct sysctlnode node; struct gpiopwm_softc *sc; int val, error; node = *rnode; sc = node.sysctl_data; callout_halt(&sc->sc_pulse, NULL); gpio_pin_write(sc->sc_gpio, &sc->sc_map, 0, GPIO_PIN_LOW); node.sysctl_data = &val; val = sc->sc_ticks_on; error = sysctl_lookup(SYSCTLFN_CALL(&node)); if (error || newp == NULL) return error; sc->sc_ticks_on = val; if (sc->sc_ticks_on > 0 && sc->sc_ticks_off > 0) { gpio_pin_write(sc->sc_gpio, &sc->sc_map, 0, GPIO_PIN_HIGH); callout_schedule(&sc->sc_pulse, sc->sc_ticks_on); } return 0; } static int gpiopwm_set_off(SYSCTLFN_ARGS) { struct sysctlnode node; struct gpiopwm_softc *sc; int val, error; node = *rnode; sc = node.sysctl_data; callout_halt(&sc->sc_pulse, NULL); gpio_pin_write(sc->sc_gpio, &sc->sc_map, 0, GPIO_PIN_LOW); node.sysctl_data = &val; val = sc->sc_ticks_off; error = sysctl_lookup(SYSCTLFN_CALL(&node)); if (error || newp == NULL) return error; sc->sc_ticks_off = val; if (sc->sc_ticks_on > 0 && sc->sc_ticks_off > 0) { gpio_pin_write(sc->sc_gpio, &sc->sc_map, 0, GPIO_PIN_HIGH); callout_schedule(&sc->sc_pulse, sc->sc_ticks_on); } return 0; } static void gpiopwm_pulse(void *arg) { struct gpiopwm_softc *sc; sc = arg; if (gpio_pin_read(sc->sc_gpio, &sc->sc_map, 0) == GPIO_PIN_HIGH) { gpio_pin_write(sc->sc_gpio, &sc->sc_map, 0, GPIO_PIN_LOW); callout_schedule(&sc->sc_pulse, sc->sc_ticks_off); } else { gpio_pin_write(sc->sc_gpio, &sc->sc_map, 0, GPIO_PIN_HIGH); callout_schedule(&sc->sc_pulse, sc->sc_ticks_on); } } int gpiopwm_activate(device_t self, enum devact act) { struct gpiopwm_softc *sc = device_private(self); switch (act) { case DVACT_DEACTIVATE: sc->sc_dying = 1; return 0; default: return EOPNOTSUPP; } }