FreeBSD/Linux Kernel Cross Reference
sys/mips/ingenic/jz4780_efuse.c

     /*-
      * Copyright (c) 2015 Alexander Kabaev <kan@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.
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD$");
    
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/bus.h>
    #include <sys/clock.h>
    #include <sys/kernel.h>
    #include <sys/limits.h>
    #include <sys/lock.h>
    #include <sys/mutex.h>
    #include <sys/module.h>
    #include <sys/resource.h>
    
    #include <machine/bus.h>
    #include <machine/resource.h>
    
    #include <dev/fdt/fdt_common.h>
    #include <dev/ofw/ofw_bus.h>
    #include <dev/ofw/ofw_bus_subr.h>
    
    #include <mips/ingenic/jz4780_regs.h>
    
    static struct ofw_compat_data compat_data[] = {
            {"ingenic,jz4780-efuse",        1},
            {NULL,                          0}
    };
    
    struct jz4780_efuse_data {
            uint32_t serial_num;
            uint32_t date;
            uint8_t  nanufacturer[2];
            uint8_t  macaddr[6];
    } __packed;
    
    static struct resource_spec jz4780_efuse_spec[] = {
            { SYS_RES_MEMORY, 0, RF_ACTIVE },
            { -1, 0 }
    };
    
    struct jz4780_efuse_softc {
            device_t                dev;
            struct resource         *res[1];
            struct jz4780_efuse_data data;
    };
    
    #define CSR_WRITE_4(sc, reg, val) \
        bus_write_4((sc)->res[0], (reg), (val))
    #define CSR_READ_4(sc, reg) \
        bus_read_4((sc)->res[0], (reg))
    
    #define JZ_EFUSE_BANK_SIZE      (4096 / 8) /* Bank size is 4096 bits */
    
    static int
    jz4780_efuse_probe(device_t dev)
    {
            if (!ofw_bus_status_okay(dev))
                    return (ENXIO);
    
            if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0)
                    return (ENXIO);
    
            return (BUS_PROBE_DEFAULT);
    }
    
    static void
    jz4780_efuse_read_chunk(struct jz4780_efuse_softc *sc, int addr, uint8_t *buf, int len)
    {
            uint32_t abuf;
            int i, count;
    
            /* Setup to read proper bank */
            CSR_WRITE_4(sc, JZ_EFUCTRL, JZ_EFUSE_READ |
               (addr < JZ_EFUSE_BANK_SIZE ? 0: JZ_EFUSE_BANK) |
               (addr << JZ_EFUSE_ADDR_SHIFT) |
               ((len - 1) << JZ_EFUSE_SIZE_SHIFT));
           /* Wait for read to complete */
           while ((CSR_READ_4(sc, JZ_EFUSTATE) & JZ_EFUSE_RD_DONE) == 0)
                   DELAY(1000);
   
           /* Round to 4 bytes for the simple loop below */
           count = len & ~3;
   
           for (i = 0; i < count; i += 4) {
                   abuf = CSR_READ_4(sc, JZ_EFUDATA0 + i);
                   memcpy(buf, &abuf, 4);
                   buf += 4;
           }
   
           /* Read partial word and assign it byte-by-byte */
           if (i < len) {
                   abuf = CSR_READ_4(sc, JZ_EFUDATA0 + i);
                   for (/* none */; i < len; i++) {
                           buf[i] = abuf & 0xff;
                           abuf >>= 8;
                   }
           }
   }
   
   static void
   jz4780_efuse_read(struct jz4780_efuse_softc *sc, int addr, void *buf, int len)
   {
           int chunk;
   
           while (len > 0) {
                   chunk = (len > 32) ? 32 : len;
                   jz4780_efuse_read_chunk(sc, addr, buf, chunk);
                   len -= chunk;
                   buf = (void *)((uintptr_t)buf + chunk);
                   addr += chunk;
           }
   }
   
   static void
   jz4780_efuse_update_kenv(struct jz4780_efuse_softc *sc)
   {
           char macstr[sizeof("xx:xx:xx:xx:xx:xx")];
   
           /*
            * Update hint in kernel env only if none is available yet.
            * It is quite possible one was set by command line already.
            */
           if (kern_getenv("hint.dme.0.macaddr") == NULL) {
                   snprintf(macstr, sizeof(macstr), "%6D",
                       sc->data.macaddr, ":");
                   kern_setenv("hint.dme.0.macaddr", macstr);
           }
   }
   
   static int
   jz4780_efuse_attach(device_t dev)
   {
           struct jz4780_efuse_softc *sc;
   
           sc = device_get_softc(dev);
           sc->dev = dev;
   
           if (bus_alloc_resources(dev, jz4780_efuse_spec, sc->res)) {
                   device_printf(dev, "could not allocate resources for device\n");
                   return (ENXIO);
           }
   
           /*
            * Default RD_STROBE to 4 h2clk cycles, should already be set to 4 by  reset
            * but configure it anyway.
            */
           CSR_WRITE_4(sc, JZ_EFUCFG, 0x00040000);
   
           /* Read user-id segment */
           jz4780_efuse_read(sc, 0x18, &sc->data, sizeof(sc->data));
   
           /*
            * Set resource hints for the dme device to discover its
            * MAC address, if not set already.
            */
           jz4780_efuse_update_kenv(sc);
   
           /* Resource conflicts with NEMC, release early */
           bus_release_resources(dev, jz4780_efuse_spec, sc->res);
           return (0);
   }
   
   static int
   jz4780_efuse_detach(device_t dev)
   {
   
           return (0);
   }
   
   static device_method_t jz4780_efuse_methods[] = {
           /* Device interface */
           DEVMETHOD(device_probe,         jz4780_efuse_probe),
           DEVMETHOD(device_attach,        jz4780_efuse_attach),
           DEVMETHOD(device_detach,        jz4780_efuse_detach),
   
           DEVMETHOD_END
   };
   
   static driver_t jz4780_efuse_driver = {
           "efuse",
           jz4780_efuse_methods,
           sizeof(struct jz4780_efuse_softc),
   };
   
   static devclass_t jz4780_efuse_devclass;
   EARLY_DRIVER_MODULE(jz4780_efuse, simplebus, jz4780_efuse_driver,
       jz4780_efuse_devclass, 0, 0, BUS_PASS_TIMER);

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