text: /*-
   * 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("$FreeBSD$");
  
  #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 <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_status_okay(dev))
  		return (ENXIO);
  
  	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		2731
  #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);
  