openwrt/target/linux/olpc/files/arch/i386/kernel/ofw.c

101 lines
3.1 KiB
C

/*
* ofw.c - Open Firmware client interface for 32-bit systems.
* This code is intended to be portable to any 32-bit Open Firmware
* implementation with a standard client interface that can be
* called when Linux is running.
*
* Copyright (C) 2007 Mitch Bradley <wmb@firmworks.com>
* Copyright (C) 2007 Andres Salomon <dilinger@debian.org>
*/
#include <stdarg.h>
#include <linux/spinlock.h>
#include <linux/module.h>
#include <asm/ofw.h>
int (*call_firmware)(int *);
static DEFINE_SPINLOCK(prom_lock);
#define MAXARGS 20
/*
* The return value from ofw() in all cases is 0 if the attempt to call the
* function succeeded, <0 otherwise. That return value is from the
* gateway function only. Any results from the called function are returned
* via output argument pointers.
*
* Here are call templates for all the standard OFW client services:
*
* ofw("test", 1, 1, namestr, &missing);
* ofw("peer", 1, 1, phandle, &sibling_phandle);
* ofw("child", 1, 1, phandle, &child_phandle);
* ofw("parent", 1, 1, phandle, &parent_phandle);
* ofw("instance_to_package", 1, 1, ihandle, &phandle);
* ofw("getproplen", 2, 1, phandle, namestr, &proplen);
* ofw("getprop", 4, 1, phandle, namestr, bufaddr, buflen, &size);
* ofw("nextprop", 3, 1, phandle, previousstr, bufaddr, &flag);
* ofw("setprop", 4, 1, phandle, namestr, bufaddr, len, &size);
* ofw("canon", 3, 1, devspecstr, bufaddr, buflen, &length);
* ofw("finddevice", 1, 1, devspecstr, &phandle);
* ofw("instance-to-path", 3, 1, ihandle, bufaddr, buflen, &length);
* ofw("package-to-path", 3, 1, phandle, bufaddr, buflen, &length);
* ofw("call_method", numin, numout, in0, in1, ..., &out0, &out1, ...);
* ofw("open", 1, 1, devspecstr, &ihandle);
* ofw("close", 1, 0, ihandle);
* ofw("read", 3, 1, ihandle, addr, len, &actual);
* ofw("write", 3, 1, ihandle, addr, len, &actual);
* ofw("seek", 3, 1, ihandle, pos_hi, pos_lo, &status);
* ofw("claim", 3, 1, virtaddr, size, align, &baseaddr);
* ofw("release", 2, 0, virtaddr, size);
* ofw("boot", 1, 0, bootspecstr);
* ofw("enter", 0, 0);
* ofw("exit", 0, 0);
* ofw("chain", 5, 0, virtaddr, size, entryaddr, argsaddr, len);
* ofw("interpret", numin+1, numout+1, cmdstr, in0, ..., &catchres, &out0, ...);
* ofw("set-callback", 1, 1, newfuncaddr, &oldfuncaddr);
* ofw("set-symbol-lookup", 2, 0, symtovaladdr, valtosymaddr);
* ofw("milliseconds", 0, 1, &ms);
*/
int ofw(char *name, int numargs, int numres, ...)
{
va_list ap;
int argarray[MAXARGS+3];
int argnum = 3;
int retval;
int *intp;
unsigned long flags;
if (!call_firmware)
return -1;
if ((numargs + numres) > MAXARGS)
return -1; /* spit out an error? */
argarray[0] = (int) name;
argarray[1] = numargs;
argarray[2] = numres;
va_start(ap, numres);
while (numargs) {
argarray[argnum++] = va_arg(ap, int);
numargs--;
}
spin_lock_irqsave(&prom_lock, flags);
retval = call_firmware(argarray);
spin_unlock_irqrestore(&prom_lock, flags);
if (retval == 0) {
while (numres) {
intp = va_arg(ap, int *);
*intp = argarray[argnum++];
numres--;
}
}
va_end(ap);
return retval;
}
EXPORT_SYMBOL(ofw);