FreeBSD/Linux Kernel Cross Reference
sys/arm/mv/mv_ts.c

     /*-
      * Copyright (c) 2012 Hiroki Sato <hrs@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.
     *
     * Driver for on-die thermal sensor in 88F6282 and 88F6283.
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD: releng/10.0/sys/arm/mv/mv_ts.c 239371 2012-08-18 12:37:07Z hrs $");
    
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/kernel.h>
    #include <sys/module.h>
    #include <sys/bus.h>
    #include <sys/sysctl.h>
    #include <machine/fdt.h>
    
    #include <dev/fdt/fdt_common.h>
    #include <dev/ofw/ofw_bus.h>
    #include <dev/ofw/ofw_bus_subr.h>
    
    #include <arm/mv/mvreg.h>
    #include <arm/mv/mvvar.h>
    
    static struct resource_spec mvts_res[] = {
            { SYS_RES_MEMORY,       0,      RF_ACTIVE },
            { -1, 0 }
    };
    
    struct mvts_softc {
            device_t                sc_dev;
            struct resource         *sc_res[sizeof(mvts_res)];
    };
    
    static int
    ts_probe(device_t dev)
    {
            uint32_t d, r;
    
            if (!ofw_bus_is_compatible(dev, "mrvl,ts"))
                    return (ENXIO);
            soc_id(&d, &r);
            switch (d) {
            case MV_DEV_88F6282:
                    break;
            default:
                    device_printf(dev, "unsupported SoC (ID: 0x%08X)!\n", d);
                    return (ENXIO);
            }
            device_set_desc(dev, "Marvell Thermal Sensor");
    
            return (0);
    }
    
    #define MV_TEMP_VALID_BIT       (1 << 9)
    #define MV_TEMP_SENS_OFFS       10
    #define MV_TEMP_SENS_MASK       0x1ff
    #define MV_TEMP_SENS_READ_MAX   16
    #define TZ_ZEROC                2732
    #define MV_TEMP_CONVERT(x)      ((((322 - x) * 100000) / 13625) + TZ_ZEROC)
    
    /*
     * MSB                                 LSB
     * 0000 0000 0000 0000 0000 0000 0000 0000
     *                             ^- valid bit
     *                  |---------|
     *                         ^--- temperature (9 bits)
     */
    
    static int
    ts_sysctl_handler(SYSCTL_HANDLER_ARGS)
    {
            struct mvts_softc *sc;
            device_t dev;
            uint32_t ret, ret0;
            u_int val;
            int i;
   
           dev = (device_t)arg1;
           sc = device_get_softc(dev);
           val = TZ_ZEROC;
   
           ret = bus_read_4(sc->sc_res[0], 0);
           if ((ret & MV_TEMP_VALID_BIT) == 0) {
                   device_printf(dev, "temperature sensor is broken.\n");
                   goto ts_sysctl_handle_int;
           }
           ret0 = 0;
           for (i = 0; i < MV_TEMP_SENS_READ_MAX; i++) {
                   ret = bus_read_4(sc->sc_res[0], 0);
                   ret = (ret >> MV_TEMP_SENS_OFFS) & MV_TEMP_SENS_MASK;
   
                   /*
                    * Successive reads should returns the same value except
                    * for the LSB when the sensor is normal.
                    */
                   if (((ret0 ^ ret) & 0x1fe) == 0)
                           break;
                   else
                           ret0 = ret;
           }
           if (i == MV_TEMP_SENS_READ_MAX) {
                   device_printf(dev, "temperature sensor is unstable.\n");
                   goto ts_sysctl_handle_int;
           }
           val = (u_int)MV_TEMP_CONVERT(ret);
   
   ts_sysctl_handle_int:
           return (sysctl_handle_int(oidp, &val, 0, req));
   }
   
   static int
   ts_attach(device_t dev)
   {
           struct mvts_softc *sc;
           struct sysctl_ctx_list *ctx;
           int error;
   
           sc = device_get_softc(dev);
           sc->sc_dev = dev;
           error = bus_alloc_resources(dev, mvts_res, sc->sc_res);
           if (error) {
                   device_printf(dev, "could not allocate resources\n");
                   return (ENXIO);
           }
           ctx = device_get_sysctl_ctx(dev);
           SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(device_get_sysctl_tree(dev)),
               OID_AUTO, "temperature", CTLTYPE_INT | CTLFLAG_RD, dev,
               0, ts_sysctl_handler, "IK", "Current Temperature");
   
           return (0);
   }
   
   static int
   ts_detach(device_t dev)
   {
   
           return (0);
   }
   
   static device_method_t ts_methods[] = {
           DEVMETHOD(device_probe,         ts_probe),
           DEVMETHOD(device_attach,        ts_attach),
           DEVMETHOD(device_detach,        ts_detach),
           {0, 0},
   };
   
   static driver_t ts_driver = {
           "mvts",
           ts_methods,
           sizeof(struct mvts_softc),
   };
   
   static devclass_t ts_devclass;
   DRIVER_MODULE(mvts, simplebus, ts_driver, ts_devclass, 0, 0);
   MODULE_VERSION(mvts, 1);

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