FreeBSD/Linux Kernel Cross Reference
sys/arm/ti/ti_scm.c

     /*
      * Copyright (c) 2010
      *      Ben Gray <ben.r.gray@gmail.com>.
      * 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.
     * 3. All advertising materials mentioning features or use of this software
     *    must display the following acknowledgement:
     *      This product includes software developed by Ben Gray.
     * 4. The name of the company nor the name of the author may be used to
     *    endorse or promote products derived from this software without specific
     *    prior written permission.
     *
     * THIS SOFTWARE IS PROVIDED BY BEN GRAY ``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 BEN GRAY 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.
     */
    
    /**
     *      SCM - System Control Module
     *
     *      Hopefully in the end this module will contain a bunch of utility functions
     *      for configuring and querying the general system control registers, but for
     *      now it only does pin(pad) multiplexing.
     *
     *      This is different from the GPIO module in that it is used to configure the
     *      pins between modules not just GPIO input/output.
     *
     *      This file contains the generic top level driver, however it relies on chip
     *      specific settings and therefore expects an array of ti_scm_padconf structs
     *      call ti_padconf_devmap to be located somewhere in the kernel.
     *
     */
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD$");
    
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/kernel.h>
    #include <sys/module.h>
    #include <sys/bus.h>
    #include <sys/resource.h>
    #include <sys/rman.h>
    #include <sys/lock.h>
    #include <sys/mutex.h>
    
    #include <machine/bus.h>
    #include <machine/resource.h>
    
    #include <dev/fdt/fdt_common.h>
    #include <dev/fdt/fdt_pinctrl.h>
    #include <dev/ofw/openfirm.h>
    #include <dev/ofw/ofw_bus.h>
    #include <dev/ofw/ofw_bus_subr.h>
    
    #include "ti_scm.h"
    
    static struct resource_spec ti_scm_res_spec[] = {
            { SYS_RES_MEMORY,       0,      RF_ACTIVE },    /* Control memory window */
            { -1, 0 }
    };
    
    static struct ti_scm_softc *ti_scm_sc;
    
    #define ti_scm_read_4(sc, reg)          \
        bus_space_read_4((sc)->sc_bst, (sc)->sc_bsh, (reg))
    #define ti_scm_write_4(sc, reg, val)            \
        bus_space_write_4((sc)->sc_bst, (sc)->sc_bsh, (reg), (val))
    
    /*
     * Device part of OMAP SCM driver
     */
    static int
    ti_scm_probe(device_t dev)
    {
            if (!ofw_bus_status_okay(dev))
                    return (ENXIO);
    
            if (!ofw_bus_is_compatible(dev, "syscon"))
                    return (ENXIO);
    
            if (ti_scm_sc) {
                    return (EEXIST);
            }
    
           device_set_desc(dev, "TI Control Module");
           return (BUS_PROBE_DEFAULT);
   }
   
   /**
    *      ti_scm_attach - attaches the timer to the simplebus
    *      @dev: new device
    *
    *      Reserves memory and interrupt resources, stores the softc structure
    *      globally and registers both the timecount and eventtimer objects.
    *
    *      RETURNS
    *      Zero on success or ENXIO if an error occuried.
    */
   static int
   ti_scm_attach(device_t dev)
   {
           struct ti_scm_softc *sc = device_get_softc(dev);
   
           sc->sc_dev = dev;
   
           if (bus_alloc_resources(dev, ti_scm_res_spec, sc->sc_res)) {
                   device_printf(dev, "could not allocate resources\n");
                   return (ENXIO);
           }
   
           /* Global timer interface */
           sc->sc_bst = rman_get_bustag(sc->sc_res[0]);
           sc->sc_bsh = rman_get_bushandle(sc->sc_res[0]);
   
           ti_scm_sc = sc;
   
           /* Attach platform extensions, if any. */
           bus_generic_probe(dev);
   
           return (bus_generic_attach(dev));
   }
   
   int
   ti_scm_reg_read_4(uint32_t reg, uint32_t *val)
   {
           if (!ti_scm_sc)
                   return (ENXIO);
   
           *val = ti_scm_read_4(ti_scm_sc, reg);
           return (0);
   }
   
   int
   ti_scm_reg_write_4(uint32_t reg, uint32_t val)
   {
           if (!ti_scm_sc)
                   return (ENXIO);
   
           ti_scm_write_4(ti_scm_sc, reg, val);
           return (0);
   }
   
   
   static device_method_t ti_scm_methods[] = {
           DEVMETHOD(device_probe,         ti_scm_probe),
           DEVMETHOD(device_attach,        ti_scm_attach),
   
           { 0, 0 }
   };
   
   static driver_t ti_scm_driver = {
           "ti_scm",
           ti_scm_methods,
           sizeof(struct ti_scm_softc),
   };
   
   static devclass_t ti_scm_devclass;
   
   EARLY_DRIVER_MODULE(ti_scm, simplebus, ti_scm_driver, ti_scm_devclass, 0, 0,
       BUS_PASS_BUS + BUS_PASS_ORDER_MIDDLE);

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