freebsd-skq/sys/mips/sibyte/sb_scd.c

/*-
 * Copyright (c) 2009 Neelkanth Natu
 * 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/param.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/module.h>
#include <sys/bus.h>

#include <machine/resource.h>

#include "sb_scd.h"

__FBSDID("$FreeBSD$");

/*
 * System Control and Debug (SCD) unit on the Sibyte ZBbus.
 */

/*
 * Extract the value starting at bit position 'b' for 'n' bits from 'x'.
 */
#define	GET_VAL_64(x, b, n)	(((x) >> (b)) & ((1ULL << (n)) - 1))

#define SYSCFG_PLLDIV(x)	GET_VAL_64((x), 7, 5)

uint64_t
sb_cpu_speed(void)
{
	int plldiv;
	const uint64_t MHZ = 1000000;
	
	plldiv = SYSCFG_PLLDIV(sb_read_syscfg());
	if (plldiv == 0) {
		printf("PLL_DIV is 0 - assuming 6 (300MHz).\n");
		plldiv = 6;
	}

	return (plldiv * 50 * MHZ);
}

void
sb_system_reset(void)
{
	uint64_t syscfg;

	const uint64_t SYSTEM_RESET = 1ULL << 60;
	const uint64_t EXT_RESET = 1ULL << 59;
	const uint64_t SOFT_RESET = 1ULL << 58;

	syscfg = sb_read_syscfg();
	syscfg &= ~SOFT_RESET;
	syscfg |= SYSTEM_RESET | EXT_RESET;
	sb_write_syscfg(syscfg);
}

int
sb_route_intsrc(int intsrc)
{
	int intrnum;

	KASSERT(intsrc >= 0 && intsrc < NUM_INTSRC,
		("Invalid interrupt source number (%d)", intsrc));

	/*
	 * Interrupt 5 is used by sources internal to the CPU (e.g. timer).
	 * Use a deterministic mapping for the remaining sources to map to
	 * interrupt numbers 0 through 4.
	 */
	intrnum = intsrc % 5;

	/*
	 * Program the interrupt mapper while we are here.
	 */
	sb_write_intmap(intsrc, intrnum);

	return (intrnum);
}

#define	SCD_PHYSADDR	0x10000000
#define	SCD_SIZE	0x00060000

static int
scd_probe(device_t dev)
{

	device_set_desc(dev, "Broadcom/Sibyte System Control and Debug");
	return (0);
}

static int
scd_attach(device_t dev)
{
	int rid;
	struct resource *res;

	if (bootverbose) {
		device_printf(dev, "attached.\n");
	}

	rid = 0;
	res = bus_alloc_resource(dev, SYS_RES_MEMORY, &rid, SCD_PHYSADDR,
				 SCD_PHYSADDR + SCD_SIZE - 1, SCD_SIZE, 0);
	if (res == NULL) {
		panic("Cannot allocate resource for system control and debug.");
	}
	
	return (0);
}

static device_method_t scd_methods[] ={
	/* Device interface */
	DEVMETHOD(device_probe,		scd_probe),
	DEVMETHOD(device_attach,	scd_attach),
	DEVMETHOD(device_detach,	bus_generic_detach),
	DEVMETHOD(device_shutdown,	bus_generic_shutdown),
	DEVMETHOD(device_suspend,	bus_generic_suspend),
	DEVMETHOD(device_resume,	bus_generic_resume),

	{ 0, 0 }
};

static driver_t scd_driver = {
	"scd",
	scd_methods
};

static devclass_t scd_devclass;

DRIVER_MODULE(scd, zbbus, scd_driver, scd_devclass, 0, 0);