FreeBSD/Linux Kernel Cross Reference
sys/powerpc/cpufreq/pmufreq.c

     /*-
      * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
      *
      * Copyright (c) 2011 Justin Hibbits
      * Copyright (c) 2009 Nathan Whitehorn
      * 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.
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD$");
    
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/bus.h>
    #include <sys/cpu.h>
    #include <sys/kernel.h>
    #include <sys/limits.h>
    #include <sys/module.h>
    
    #include <dev/ofw/ofw_bus.h>
    #include <dev/ofw/openfirm.h>
    
    #include "cpufreq_if.h"
    #include "powerpc/powermac/pmuvar.h"
    
    struct pmufreq_softc {
            device_t dev;
            uint32_t minfreq;
            uint32_t maxfreq;
            uint32_t curfreq;
    };
    
    static void     pmufreq_identify(driver_t *driver, device_t parent);
    static int      pmufreq_probe(device_t dev);
    static int      pmufreq_attach(device_t dev);
    static int      pmufreq_settings(device_t dev, struct cf_setting *sets, int *count);
    static int      pmufreq_set(device_t dev, const struct cf_setting *set);
    static int      pmufreq_get(device_t dev, struct cf_setting *set);
    static int      pmufreq_type(device_t dev, int *type);
    
    static device_method_t pmufreq_methods[] = {
            /* Device interface */
            DEVMETHOD(device_identify,      pmufreq_identify),
            DEVMETHOD(device_probe,         pmufreq_probe),
            DEVMETHOD(device_attach,        pmufreq_attach),
    
            /* cpufreq interface */
            DEVMETHOD(cpufreq_drv_set,      pmufreq_set),
            DEVMETHOD(cpufreq_drv_get,      pmufreq_get),
            DEVMETHOD(cpufreq_drv_type,     pmufreq_type),
            DEVMETHOD(cpufreq_drv_settings, pmufreq_settings),
            {0, 0}
    };
    
    static driver_t pmufreq_driver = {
            "pmufreq",
            pmufreq_methods,
            sizeof(struct pmufreq_softc)
    };
    
    DRIVER_MODULE(pmufreq, cpu, pmufreq_driver, 0, 0);
    
    static void
    pmufreq_identify(driver_t *driver, device_t parent)
    {
            phandle_t node;
            uint32_t min_freq;
    
            node = ofw_bus_get_node(parent);
            if (OF_getprop(node, "min-clock-frequency", &min_freq, sizeof(min_freq)) == -1)
                    return;
    
            /* Make sure we're not being doubly invoked. */
            if (device_find_child(parent, "pmufreq", -1) != NULL)
                    return;
    
            /*
             * We attach a child for every CPU since settings need to
            * be performed on every CPU in the SMP case.
            */
           if (BUS_ADD_CHILD(parent, 10, "pmufreq", -1) == NULL)
                   device_printf(parent, "add pmufreq child failed\n");
   }
   
   static int
   pmufreq_probe(device_t dev)
   {
           phandle_t node;
           uint32_t min_freq;
   
           if (resource_disabled("pmufreq", 0))
                   return (ENXIO);
   
           node = ofw_bus_get_node(device_get_parent(dev));
           /*
            * A scalable MPC7455 has min-clock-frequency/max-clock-frequency as OFW
            * properties of the 'cpu' node.
            */
           if (OF_getprop(node, "min-clock-frequency", &min_freq, sizeof(min_freq)) == -1)
                   return (ENXIO);
           device_set_desc(dev, "PMU-based frequency scaling");
           return (0);
   }
   
   static int
   pmufreq_attach(device_t dev)
   {
           struct pmufreq_softc *sc;
           phandle_t node;
   
           sc = device_get_softc(dev);
           sc->dev = dev;
   
           node = ofw_bus_get_node(device_get_parent(dev));
           OF_getprop(node, "min-clock-frequency", &sc->minfreq, sizeof(sc->minfreq));
           OF_getprop(node, "max-clock-frequency", &sc->maxfreq, sizeof(sc->maxfreq));
           OF_getprop(node, "rounded-clock-frequency", &sc->curfreq, sizeof(sc->curfreq));
           sc->minfreq /= 1000000;
           sc->maxfreq /= 1000000;
           sc->curfreq /= 1000000;
   
           cpufreq_register(dev);
           return (0);
   }
   
   static int
   pmufreq_settings(device_t dev, struct cf_setting *sets, int *count)
   {
           struct pmufreq_softc *sc;
   
           sc = device_get_softc(dev);
           if (sets == NULL || count == NULL)
                   return (EINVAL);
           if (*count < 2)
                   return (E2BIG);
   
           /* Return a list of valid settings for this driver. */
           memset(sets, CPUFREQ_VAL_UNKNOWN, sizeof(*sets) * 2);
   
           sets[0].freq = sc->maxfreq; sets[0].dev = dev;
           sets[1].freq = sc->minfreq; sets[1].dev = dev;
           /* Set high latency for CPU frequency changes, it's a tedious process. */
           sets[0].lat = INT_MAX;
           sets[1].lat = INT_MAX;
           *count = 2;
   
           return (0);
   }
   
   static int
   pmufreq_set(device_t dev, const struct cf_setting *set)
   {
           struct pmufreq_softc *sc;
           int error, speed_sel;
   
           if (set == NULL)
                   return (EINVAL);
   
           sc = device_get_softc(dev);
   
           if (set->freq == sc->maxfreq)
                   speed_sel = 0;
           else
                   speed_sel = 1;
   
           error = pmu_set_speed(speed_sel);
           if (error == 0)
                   sc->curfreq = set->freq;
   
           return (error);
   }
   
   static int
   pmufreq_get(device_t dev, struct cf_setting *set)
   {
           struct pmufreq_softc *sc;
   
           if (set == NULL)
                   return (EINVAL);
           sc = device_get_softc(dev);
   
           set->freq = sc->curfreq;
           set->dev = dev;
   
           return (0);
   }
   
   static int
   pmufreq_type(device_t dev, int *type)
   {
   
           if (type == NULL)
                   return (EINVAL);
   
           *type = CPUFREQ_TYPE_ABSOLUTE;
           return (0);
   }

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