FreeBSD/Linux Kernel Cross Reference
sys/dev/spibus/spibus.c

     /*-
      * Copyright (c) 2006 M. Warner Losh
      * 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.
     *
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD: releng/12.0/sys/dev/spibus/spibus.c 335506 2018-06-21 21:16:26Z ian $");
    
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/malloc.h>
    #include <sys/module.h>
    #include <sys/kernel.h>
    #include <sys/queue.h>
    #include <sys/sysctl.h>
    #include <sys/types.h>
    
    #include <sys/bus.h>
    #include <machine/bus.h>
    #include <sys/rman.h>
    #include <machine/resource.h>
    
    #include <dev/spibus/spibusvar.h>
    #include <dev/spibus/spi.h>
    #include "spibus_if.h"
    
    static int
    spibus_probe(device_t dev)
    {
    
            device_set_desc(dev, "SPI bus");
            return (BUS_PROBE_DEFAULT);
    }
    
    static int
    spibus_attach(device_t dev)
    {
            struct spibus_softc *sc = SPIBUS_SOFTC(dev);
    
            sc->dev = dev;
            bus_enumerate_hinted_children(dev);
            return (bus_generic_attach(dev));
    }
    
    /*
     * Since this is not a self-enumerating bus, and since we always add
     * children in attach, we have to always delete children here.
     */
    static int
    spibus_detach(device_t dev)
    {
            int err;
    
            if ((err = bus_generic_detach(dev)) != 0)
                    return (err);
            device_delete_children(dev);
    
            return (0);
    }
    
    static int
    spibus_suspend(device_t dev)
    {
            return (bus_generic_suspend(dev));
    }
    
    static
    int
    spibus_resume(device_t dev)
    {
            return (bus_generic_resume(dev));
    }
    
    static int
    spibus_print_child(device_t dev, device_t child)
    {
            struct spibus_ivar *devi = SPIBUS_IVAR(child);
           int retval = 0;
   
           retval += bus_print_child_header(dev, child);
           retval += printf(" at cs %d", devi->cs);
           retval += printf(" mode %d", devi->mode);
           retval += bus_print_child_footer(dev, child);
   
           return (retval);
   }
   
   static void
   spibus_probe_nomatch(device_t bus, device_t child)
   {
           struct spibus_ivar *devi = SPIBUS_IVAR(child);
   
           device_printf(bus, "<unknown card> at cs %d mode %d\n", devi->cs,
               devi->mode);
           return;
   }
   
   static int
   spibus_child_location_str(device_t bus, device_t child, char *buf,
       size_t buflen)
   {
           struct spibus_ivar *devi = SPIBUS_IVAR(child);
           int cs;
   
           cs = devi->cs & ~SPIBUS_CS_HIGH; /* trim 'cs high' bit */
           snprintf(buf, buflen, "bus=%d cs=%d", device_get_unit(bus), cs);
           return (0);
   }
   
   static int
   spibus_child_pnpinfo_str(device_t bus, device_t child, char *buf,
       size_t buflen)
   {
           *buf = '\0';
           return (0);
   }
   
   static int
   spibus_read_ivar(device_t bus, device_t child, int which, uintptr_t *result)
   {
           struct spibus_ivar *devi = SPIBUS_IVAR(child);
   
           switch (which) {
           default:
                   return (EINVAL);
           case SPIBUS_IVAR_CS:
                   *(uint32_t *)result = devi->cs;
                   break;
           case SPIBUS_IVAR_MODE:
                   *(uint32_t *)result = devi->mode;
                   break;
           case SPIBUS_IVAR_CLOCK:
                   *(uint32_t *)result = devi->clock;
                   break;
           }
           return (0);
   }
   
   static int
   spibus_write_ivar(device_t bus, device_t child, int which, uintptr_t value)
   {
           struct spibus_ivar *devi = SPIBUS_IVAR(child);
   
           if (devi == NULL || device_get_parent(child) != bus)
                   return (EDOOFUS);
   
           switch (which) {
           case SPIBUS_IVAR_CLOCK:
                   /* Any non-zero value is allowed for max clock frequency. */
                   if (value == 0)
                           return (EINVAL);
                   devi->clock = (uint32_t)value;
                   break;
           case SPIBUS_IVAR_CS:
                    /* Chip select cannot be changed. */
                   return (EINVAL);
           case SPIBUS_IVAR_MODE:
                   /* Valid SPI modes are 0-3. */
                   if (value > 3)
                           return (EINVAL);
                   devi->mode = (uint32_t)value;
                   break;
           default:
                   return (EINVAL);
           }
   
           return (0);
   }
   
   static device_t
   spibus_add_child(device_t dev, u_int order, const char *name, int unit)
   {
           device_t child;
           struct spibus_ivar *devi;
   
           child = device_add_child_ordered(dev, order, name, unit);
           if (child == NULL) 
                   return (child);
           devi = malloc(sizeof(struct spibus_ivar), M_DEVBUF, M_NOWAIT | M_ZERO);
           if (devi == NULL) {
                   device_delete_child(dev, child);
                   return (0);
           }
           device_set_ivars(child, devi);
           return (child);
   }
   
   static void
   spibus_hinted_child(device_t bus, const char *dname, int dunit)
   {
           device_t child;
           struct spibus_ivar *devi;
   
           child = BUS_ADD_CHILD(bus, 0, dname, dunit);
           devi = SPIBUS_IVAR(child);
           devi->mode = SPIBUS_MODE_NONE;
           resource_int_value(dname, dunit, "cs", &devi->cs);
           resource_int_value(dname, dunit, "mode", &devi->mode);
   }
   
   static int
   spibus_transfer_impl(device_t dev, device_t child, struct spi_command *cmd)
   {
           return (SPIBUS_TRANSFER(device_get_parent(dev), child, cmd));
   }
   
   static device_method_t spibus_methods[] = {
           /* Device interface */
           DEVMETHOD(device_probe,         spibus_probe),
           DEVMETHOD(device_attach,        spibus_attach),
           DEVMETHOD(device_detach,        spibus_detach),
           DEVMETHOD(device_shutdown,      bus_generic_shutdown),
           DEVMETHOD(device_suspend,       spibus_suspend),
           DEVMETHOD(device_resume,        spibus_resume),
   
           /* Bus interface */
           DEVMETHOD(bus_add_child,        spibus_add_child),
           DEVMETHOD(bus_print_child,      spibus_print_child),
           DEVMETHOD(bus_probe_nomatch,    spibus_probe_nomatch),
           DEVMETHOD(bus_read_ivar,        spibus_read_ivar),
           DEVMETHOD(bus_write_ivar,       spibus_write_ivar),
           DEVMETHOD(bus_child_pnpinfo_str, spibus_child_pnpinfo_str),
           DEVMETHOD(bus_child_location_str, spibus_child_location_str),
           DEVMETHOD(bus_hinted_child,     spibus_hinted_child),
   
           /* spibus interface */
           DEVMETHOD(spibus_transfer,      spibus_transfer_impl),
   
           DEVMETHOD_END
   };
   
   driver_t spibus_driver = {
           "spibus",
           spibus_methods,
           sizeof(struct spibus_softc)
   };
   
   devclass_t      spibus_devclass;
   
   DRIVER_MODULE(spibus, spi, spibus_driver, spibus_devclass, 0, 0);
   MODULE_VERSION(spibus, 1);

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