root/sys/arch/evbmips/evbmips/yamon.c
/*      $NetBSD: yamon.c,v 1.14 2015/06/26 21:57:25 matt Exp $  */

/*
 * Copyright 2002 Wasabi Systems, Inc.
 * All rights reserved.
 *
 * Written by Simon Burge for Wasabi Systems, Inc.
 *
 * 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed for the NetBSD Project by
 *      Wasabi Systems, Inc.
 * 4. The name of Wasabi Systems, Inc. may not be used to endorse
 *    or promote products derived from this software without specific prior
 *    written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``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 WASABI SYSTEMS, INC
 * 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.
 */

/* XXX move to arch/mips/yamon/yamon.c or similar? */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: yamon.c,v 1.14 2015/06/26 21:57:25 matt Exp $");

#include <sys/param.h>
#include <sys/device.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/cpu.h>

#include <dev/cons.h>

#include <mips/locore.h>

#include <machine/yamon.h>

static int  yamongetc(dev_t);
static void yamonputc(dev_t, int);

/*
 * Default consdev, for errors or warnings before
 * consinit runs: use the PROM.
 */
struct consdev yamon_promcd = {
        NULL,           /* probe */
        NULL,           /* init */
        yamongetc,      /* getc */
        yamonputc,      /* putc */
        nullcnpollc,    /* pollc */
        NULL,           /* bell */
        makedev(0, 0),
        CN_DEAD,
};
/*
 * Get character from PROM console.
 */
static int
yamongetc(dev_t dev)
{
        char chr;

        while (!YAMON_GETCHAR(&chr))
                /* nothing */;
        return chr;
}

/*
 * Print a character on PROM console.
 */
static void
yamonputc(dev_t dev, int c)
{
        char chr;

        chr = c;
        YAMON_PRINT_COUNT(&chr, 1);
}

char *
yamon_getenv(const char *name)
{
        yamon_env_var *yev = yamon_envp;

        if (yev == NULL)
                return (NULL);
        while (yev->name != NULL) {
                if (strcmp(yev->name, name) == 0)
                        return (yev->val);
                yev++;
        }

        return (NULL);
}

void
yamon_print(const char *str)
{

        YAMON_PRINT(str);
}

void
yamon_exit(uint32_t rc)
{

        YAMON_EXIT(rc);
}

/*
 * Ask YAMON for the CPU frequency.
 * If "force" is set, then use a random frequency (100MHz) so
 * that at least delay() works, even though not perfectly.
 * Return 1 if YAMON returns a CPU frequency.
 */
int
yamon_setcpufreq(int force)
{
        struct cpu_info * const ci = curcpu();
        uint32_t freq;
        int ret;

        ret = YAMON_SYSCON_READ(SYSCON_BOARD_CPU_CLOCK_FREQ_ID, &freq,
            sizeof(freq));
        if (!force && (ret != 0 || freq == 0))
                return 0;

        if (ret != 0 || freq == 0) {
                freq = 100 * 1000 * 1000;
                ret = 0;
        } else
                ret = 1;

        ci->ci_cpu_freq = freq;
        ci->ci_cycles_per_hz = (freq + hz / 2) / hz;
        ci->ci_divisor_delay = ((freq + 500000) / 1000000);
        ci->ci_cctr_freq /= ci->ci_cpu_freq;
        if (mips_options.mips_cpu_flags & CPU_MIPS_DOUBLE_COUNT) {
                ci->ci_cycles_per_hz /= 2;
                ci->ci_divisor_delay /= 2;
                ci->ci_cctr_freq /= 2;
        }

        return ret;
}