FreeBSD/Linux Kernel Cross Reference
sys/arm/allwinner/aw_reset.c

     /*-
      * Copyright (c) 2016 Jared McNeill <jmcneill@invisible.ca>
      *
      * 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.
     *
     * $FreeBSD$
     */
    
    /*
     * Allwinner module software reset registers
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD$");
    
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/bus.h>
    #include <sys/rman.h>
    #include <sys/kernel.h>
    #include <sys/lock.h>
    #include <sys/module.h>
    #include <sys/mutex.h>
    #include <machine/bus.h>
    
    #include <dev/ofw/ofw_bus.h>
    #include <dev/ofw/ofw_bus_subr.h>
    
    #include <dev/extres/hwreset/hwreset.h>
    
    #include "hwreset_if.h"
    
    #define RESET_OFFSET(index)     ((index / 32) * 4)
    #define RESET_SHIFT(index)      (index % 32)
    
    static struct ofw_compat_data compat_data[] = {
            { "allwinner,sun6i-a31-ahb1-reset",     1 },
            { "allwinner,sun6i-a31-clock-reset",    1 },
            { NULL,                                 0 }
    };
    
    struct aw_reset_softc {
            struct resource         *res;
            struct mtx              mtx;
    };
    
    static struct resource_spec aw_reset_spec[] = {
            { SYS_RES_MEMORY,       0,      RF_ACTIVE },
            { -1, 0 }
    };
    
    #define RESET_READ(sc, reg)             bus_read_4((sc)->res, (reg))
    #define RESET_WRITE(sc, reg, val)       bus_write_4((sc)->res, (reg), (val))
    
    static int
    aw_reset_assert(device_t dev, intptr_t id, bool reset)
    {
            struct aw_reset_softc *sc;
            uint32_t reg_value;
    
            sc = device_get_softc(dev);
    
            mtx_lock(&sc->mtx);
            reg_value = RESET_READ(sc, RESET_OFFSET(id));
            if (reset)
                    reg_value &= ~(1 << RESET_SHIFT(id));
            else
                    reg_value |= (1 << RESET_SHIFT(id));
            RESET_WRITE(sc, RESET_OFFSET(id), reg_value);
            mtx_unlock(&sc->mtx);
    
            return (0);
    }
    
    static int
    aw_reset_is_asserted(device_t dev, intptr_t id, bool *reset)
    {
            struct aw_reset_softc *sc;
            uint32_t reg_value;
    
           sc = device_get_softc(dev);
   
           mtx_lock(&sc->mtx);
           reg_value = RESET_READ(sc, RESET_OFFSET(id));
           mtx_unlock(&sc->mtx);
   
           *reset = (reg_value & (1 << RESET_SHIFT(id))) != 0 ? false : true;
   
           return (0);
   }
   
   static int
   aw_reset_probe(device_t dev)
   {
           if (!ofw_bus_status_okay(dev))
                   return (ENXIO);
   
           if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0)
                   return (ENXIO);
   
           device_set_desc(dev, "Allwinner Module Resets");
           return (BUS_PROBE_DEFAULT);
   }
   
   static int
   aw_reset_attach(device_t dev)
   {
           struct aw_reset_softc *sc;
   
           sc = device_get_softc(dev);
   
           if (bus_alloc_resources(dev, aw_reset_spec, &sc->res) != 0) {
                   device_printf(dev, "cannot allocate resources for device\n");
                   return (ENXIO);
           }
   
           mtx_init(&sc->mtx, device_get_nameunit(dev), NULL, MTX_DEF);
   
           hwreset_register_ofw_provider(dev);
   
           return (0);
   }
   
   static device_method_t aw_reset_methods[] = {
           /* Device interface */
           DEVMETHOD(device_probe,         aw_reset_probe),
           DEVMETHOD(device_attach,        aw_reset_attach),
   
           /* Reset interface */
           DEVMETHOD(hwreset_assert,       aw_reset_assert),
           DEVMETHOD(hwreset_is_asserted,  aw_reset_is_asserted),
   
           DEVMETHOD_END
   };
   
   static driver_t aw_reset_driver = {
           "aw_reset",
           aw_reset_methods,
           sizeof(struct aw_reset_softc),
   };
   
   static devclass_t aw_reset_devclass;
   
   EARLY_DRIVER_MODULE(aw_reset, simplebus, aw_reset_driver, aw_reset_devclass,
       0, 0, BUS_PASS_RESOURCE + BUS_PASS_ORDER_MIDDLE);
   MODULE_VERSION(aw_reset, 1);

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