FreeBSD/Linux Kernel Cross Reference
sys/arm/allwinner/a20/a20_cpu_cfg.c

     /*-
      * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
      *
      * Copyright (c) 2013 Ganbold Tsagaankhuu <ganbold@freebsd.org>
      * 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 AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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.
     */
    
    /* CPU configuration module for Allwinner A20 */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD$");
    
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/bus.h>
    #include <sys/kernel.h>
    #include <sys/module.h>
    #include <sys/malloc.h>
    #include <sys/rman.h>
    #include <sys/timeet.h>
    #include <sys/timetc.h>
    #include <sys/watchdog.h>
    #include <machine/bus.h>
    #include <machine/cpu.h>
    #include <machine/intr.h>
    
    #include <dev/ofw/openfirm.h>
    #include <dev/ofw/ofw_bus.h>
    #include <dev/ofw/ofw_bus_subr.h>
    
    #include <machine/bus.h>
    
    #include "a20_cpu_cfg.h"
    
    struct a20_cpu_cfg_softc {
            struct resource         *res;
            bus_space_tag_t         bst;
            bus_space_handle_t      bsh;
    };
    
    static struct a20_cpu_cfg_softc *a20_cpu_cfg_sc = NULL;
    
    #define cpu_cfg_read_4(sc, reg)         \
            bus_space_read_4((sc)->bst, (sc)->bsh, (reg))
    #define cpu_cfg_write_4(sc, reg, val)   \
            bus_space_write_4((sc)->bst, (sc)->bsh, (reg), (val))
    
    static int
    a20_cpu_cfg_probe(device_t dev)
    {
    
            if (!ofw_bus_status_okay(dev))
                    return (ENXIO);
    
            if (ofw_bus_is_compatible(dev, "allwinner,sun7i-cpu-cfg")) {
                    device_set_desc(dev, "A20 CPU Configuration Module");
                    return(BUS_PROBE_DEFAULT);
            }
    
            return (ENXIO);
    }
    
    static int
    a20_cpu_cfg_attach(device_t dev)
    {
            struct a20_cpu_cfg_softc *sc = device_get_softc(dev);
            int rid = 0;
    
            if (a20_cpu_cfg_sc)
                    return (ENXIO);
    
            sc->res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid, RF_ACTIVE);
            if (!sc->res) {
                    device_printf(dev, "could not allocate resource\n");
                    return (ENXIO);
            }
    
            sc->bst = rman_get_bustag(sc->res);
           sc->bsh = rman_get_bushandle(sc->res);
   
           a20_cpu_cfg_sc = sc;
   
           return (0);
   }
   
   static device_method_t a20_cpu_cfg_methods[] = {
           DEVMETHOD(device_probe,         a20_cpu_cfg_probe),
           DEVMETHOD(device_attach,        a20_cpu_cfg_attach),
           { 0, 0 }
   };
   
   static driver_t a20_cpu_cfg_driver = {
           "a20_cpu_cfg",
           a20_cpu_cfg_methods,
           sizeof(struct a20_cpu_cfg_softc),
   };
   
   EARLY_DRIVER_MODULE(a20_cpu_cfg, simplebus, a20_cpu_cfg_driver, 0, 0,
       BUS_PASS_CPU + BUS_PASS_ORDER_FIRST);
   
   uint64_t
   a20_read_counter64(void)
   {
           uint32_t lo, hi;
   
           /* Latch counter, wait for it to be ready to read. */
           cpu_cfg_write_4(a20_cpu_cfg_sc, OSC24M_CNT64_CTRL_REG, CNT64_RL_EN);
           while (cpu_cfg_read_4(a20_cpu_cfg_sc, OSC24M_CNT64_CTRL_REG) & CNT64_RL_EN)
                   continue;
   
           hi = cpu_cfg_read_4(a20_cpu_cfg_sc, OSC24M_CNT64_HIGH_REG);
           lo = cpu_cfg_read_4(a20_cpu_cfg_sc, OSC24M_CNT64_LOW_REG);
   
           return (((uint64_t)hi << 32) | lo);
   }

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