FreeBSD/Linux Kernel Cross Reference
sys/arm/freescale/fsl_ocotp.c

     /*-
      * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
      *
      * Copyright (c) 2014 Steven Lawrance <stl@koffein.net>
      * 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("$FreeBSD$");
    
    /*
     * Access to the Freescale i.MX6 On-Chip One-Time-Programmable Memory
     */
    
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/kernel.h>
    #include <sys/module.h>
    #include <sys/bus.h>
    #include <sys/rman.h>
    
    #include <dev/ofw/ofw_bus.h>
    #include <dev/ofw/ofw_bus_subr.h>
    
    #include <machine/bus.h>
    
    #include <arm/freescale/fsl_ocotpreg.h>
    #include <arm/freescale/fsl_ocotpvar.h>
    
    /*
     * Find the physical address and size of the ocotp registers and devmap them,
     * returning a pointer to the virtual address of the base.
     *
     * XXX This is temporary until we've worked out all the details of controlling
     * the load order of devices.  In an ideal world this device would be up and
     * running before anything that needs it.  When we're at a point to make that
     * happen, this little block of code, and the few lines in fsl_ocotp_read_4()
     * that refer to it can be deleted.
     */
    #include <vm/vm.h>
    #include <vm/pmap.h>
    #include <dev/fdt/fdt_common.h>
    #include <sys/devmap.h>
    
    static uint32_t   *ocotp_regs;
    static vm_size_t   ocotp_size;
    
    static void
    fsl_ocotp_devmap(void)
    {
            phandle_t child, root;
            u_long base, size;
    
            if ((root = OF_finddevice("/")) == -1)
                    goto fatal;
            if ((child = fdt_depth_search_compatible(root, "fsl,imx6q-ocotp", 0)) == 0)
                    goto fatal;
            if (fdt_regsize(child, &base, &size) != 0)
                    goto fatal;
    
            ocotp_size = (vm_size_t)size;
    
            if ((ocotp_regs = pmap_mapdev((vm_offset_t)base, ocotp_size)) == NULL)
                    goto fatal;
    
            return;
    fatal:
            panic("cannot find/map the ocotp registers");
    }
    /* XXX end of temporary code */
    
    struct ocotp_softc {
            device_t        dev;
            struct resource *mem_res;
    };
    
    static struct ocotp_softc *ocotp_sc;
    
   static inline uint32_t
   RD4(struct ocotp_softc *sc, bus_size_t off)
   {
   
           return (bus_read_4(sc->mem_res, off));
   }
   
   static int
   ocotp_detach(device_t dev)
   {
   
           /* The ocotp registers are always accessible. */
           return (EBUSY);
   }
   
   static int
   ocotp_attach(device_t dev)
   {
           struct ocotp_softc *sc;
           int err, rid;
   
           sc = device_get_softc(dev);
           sc->dev = dev;
   
           /* Allocate bus_space resources. */
           rid = 0;
           sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
               RF_ACTIVE);
           if (sc->mem_res == NULL) {
                   device_printf(dev, "Cannot allocate memory resources\n");
                   err = ENXIO;
                   goto out;
           }
   
           ocotp_sc = sc;
   
           /* We're done with the temporary mapping now. */
           if (ocotp_regs != NULL)
                   pmap_unmapdev((vm_offset_t)ocotp_regs, ocotp_size);
   
           err = 0;
   
   out:
           if (err != 0)
                   ocotp_detach(dev);
   
           return (err);
   }
   
   static int
   ocotp_probe(device_t dev)
   {
   
           if (!ofw_bus_status_okay(dev))
                   return (ENXIO);
   
           if (ofw_bus_is_compatible(dev, "fsl,imx6q-ocotp") == 0)
                   return (ENXIO);
   
           device_set_desc(dev, 
               "Freescale On-Chip One-Time-Programmable Memory");
   
           return (BUS_PROBE_DEFAULT);
   }
   
   uint32_t
   fsl_ocotp_read_4(bus_size_t off)
   {
   
           if (off > FSL_OCOTP_LAST_REG)
                   panic("fsl_ocotp_read_4: offset out of range");
   
           /* If we have a softcontext use the regular bus_space read. */
           if (ocotp_sc != NULL)
                   return (RD4(ocotp_sc, off));
   
           /*
            * Otherwise establish a tempory device mapping if necessary, and read
            * the device without any help from bus_space.
            *
            * XXX Eventually the code from there down can be deleted.
            */
           if (ocotp_regs == NULL)
                   fsl_ocotp_devmap();
   
           return (ocotp_regs[off / 4]);
   }
   
   static device_method_t ocotp_methods[] = {
           /* Device interface */
           DEVMETHOD(device_probe,  ocotp_probe),
           DEVMETHOD(device_attach, ocotp_attach),
           DEVMETHOD(device_detach, ocotp_detach),
   
           DEVMETHOD_END
   };
   
   static driver_t ocotp_driver = {
           "ocotp",
           ocotp_methods,
           sizeof(struct ocotp_softc)
   };
   
   static devclass_t ocotp_devclass;
   
   EARLY_DRIVER_MODULE(ocotp, simplebus, ocotp_driver, ocotp_devclass, 0, 0,
       BUS_PASS_CPU + BUS_PASS_ORDER_FIRST);

Cache object: cbba27418eb506c93b465c65df254e83