// SPDX-License-Identifier: GPL-2.0
/*
 * misc.c:  Miscellaneous prom functions that don't belong
 *          anywhere else.
 *
 * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
 */

#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/module.h>

#include <asm/openprom.h>
#include <asm/oplib.h>
#include <asm/auxio.h>

extern void restore_current(void);

DEFINE_SPINLOCK(prom_lock);

/* Reset and reboot the machine with the command 'bcommand'. */
void
prom_reboot(char *bcommand)
{
        unsigned long flags;
        spin_lock_irqsave(&prom_lock, flags);
        (*(romvec->pv_reboot))(bcommand);
        /* Never get here. */
        restore_current();
        spin_unlock_irqrestore(&prom_lock, flags);
}

/* Forth evaluate the expression contained in 'fstring'. */
void
prom_feval(char *fstring)
{
        unsigned long flags;
        if(!fstring || fstring[0] == 0)
                return;
        spin_lock_irqsave(&prom_lock, flags);
        if(prom_vers == PROM_V0)
                (*(romvec->pv_fortheval.v0_eval))(strlen(fstring), fstring);
        else
                (*(romvec->pv_fortheval.v2_eval))(fstring);
        restore_current();
        spin_unlock_irqrestore(&prom_lock, flags);
}
EXPORT_SYMBOL(prom_feval);

/* Drop into the prom, with the chance to continue with the 'go'
 * prom command.
 */
void
prom_cmdline(void)
{
        unsigned long flags;

        spin_lock_irqsave(&prom_lock, flags);
        (*(romvec->pv_abort))();
        restore_current();
        spin_unlock_irqrestore(&prom_lock, flags);
        set_auxio(AUXIO_LED, 0);
}

/* Drop into the prom, but completely terminate the program.
 * No chance of continuing.
 */
void __noreturn
prom_halt(void)
{
        unsigned long flags;
again:
        spin_lock_irqsave(&prom_lock, flags);
        (*(romvec->pv_halt))();
        /* Never get here. */
        restore_current();
        spin_unlock_irqrestore(&prom_lock, flags);
        goto again; /* PROM is out to get me -DaveM */
}

typedef void (*sfunc_t)(void);

/* Set prom sync handler to call function 'funcp'. */
void
prom_setsync(sfunc_t funcp)
{
        if(!funcp) return;
        *romvec->pv_synchook = funcp;
}

/* Get the idprom and stuff it into buffer 'idbuf'.  Returns the
 * format type.  'num_bytes' is the number of bytes that your idbuf
 * has space for.  Returns 0xff on error.
 */
unsigned char
prom_get_idprom(char *idbuf, int num_bytes)
{
        int len;

        len = prom_getproplen(prom_root_node, "idprom");
        if((len>num_bytes) || (len==-1)) return 0xff;
        if(!prom_getproperty(prom_root_node, "idprom", idbuf, num_bytes))
                return idbuf[0];

        return 0xff;
}

/* Get the major prom version number. */
int
prom_version(void)
{
        return romvec->pv_romvers;
}

/* Get the prom plugin-revision. */
int
prom_getrev(void)
{
        return prom_rev;
}

/* Get the prom firmware print revision. */
int
prom_getprev(void)
{
        return prom_prev;
}