linux-stable/arch/x86/platform/olpc/olpc_dt.c
Daniel Drake f70d8ef474 x86, olpc: Add missing elements to device tree
In response to new device tree code in the kernel, OLPC will start
using it for probing of certain devices. However, some firmware fixes
are needed to put the devicetree into a usable state.

Retain compatibility with old firmware by fixing up the device tree
at boot-time if it does not contain the new nodes/properties that
we need for probing. This is the same approach taken on PPC platforms.

Signed-off-by: Daniel Drake <dsd@laptop.org>
Link: http://lkml.kernel.org/r/1309019658-1712-2-git-send-email-dsd@laptop.org
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Andres Salomon <dilinger@queued.net>
Cc: devicetree-discuss@lists.ozlabs.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2011-07-06 14:44:19 -07:00

304 lines
6.6 KiB
C

/*
* OLPC-specific OFW device tree support code.
*
* Paul Mackerras August 1996.
* Copyright (C) 1996-2005 Paul Mackerras.
*
* Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
* {engebret|bergner}@us.ibm.com
*
* Adapted for sparc by David S. Miller davem@davemloft.net
* Adapted for x86/OLPC by Andres Salomon <dilinger@queued.net>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/kernel.h>
#include <linux/bootmem.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/of_pdt.h>
#include <asm/olpc.h>
#include <asm/olpc_ofw.h>
static phandle __init olpc_dt_getsibling(phandle node)
{
const void *args[] = { (void *)node };
void *res[] = { &node };
if ((s32)node == -1)
return 0;
if (olpc_ofw("peer", args, res) || (s32)node == -1)
return 0;
return node;
}
static phandle __init olpc_dt_getchild(phandle node)
{
const void *args[] = { (void *)node };
void *res[] = { &node };
if ((s32)node == -1)
return 0;
if (olpc_ofw("child", args, res) || (s32)node == -1) {
pr_err("PROM: %s: fetching child failed!\n", __func__);
return 0;
}
return node;
}
static int __init olpc_dt_getproplen(phandle node, const char *prop)
{
const void *args[] = { (void *)node, prop };
int len;
void *res[] = { &len };
if ((s32)node == -1)
return -1;
if (olpc_ofw("getproplen", args, res)) {
pr_err("PROM: %s: getproplen failed!\n", __func__);
return -1;
}
return len;
}
static int __init olpc_dt_getproperty(phandle node, const char *prop,
char *buf, int bufsize)
{
int plen;
plen = olpc_dt_getproplen(node, prop);
if (plen > bufsize || plen < 1) {
return -1;
} else {
const void *args[] = { (void *)node, prop, buf, (void *)plen };
void *res[] = { &plen };
if (olpc_ofw("getprop", args, res)) {
pr_err("PROM: %s: getprop failed!\n", __func__);
return -1;
}
}
return plen;
}
static int __init olpc_dt_nextprop(phandle node, char *prev, char *buf)
{
const void *args[] = { (void *)node, prev, buf };
int success;
void *res[] = { &success };
buf[0] = '\0';
if ((s32)node == -1)
return -1;
if (olpc_ofw("nextprop", args, res) || success != 1)
return -1;
return 0;
}
static int __init olpc_dt_pkg2path(phandle node, char *buf,
const int buflen, int *len)
{
const void *args[] = { (void *)node, buf, (void *)buflen };
void *res[] = { len };
if ((s32)node == -1)
return -1;
if (olpc_ofw("package-to-path", args, res) || *len < 1)
return -1;
return 0;
}
static unsigned int prom_early_allocated __initdata;
void * __init prom_early_alloc(unsigned long size)
{
static u8 *mem;
static size_t free_mem;
void *res;
if (free_mem < size) {
const size_t chunk_size = max(PAGE_SIZE, size);
/*
* To mimimize the number of allocations, grab at least
* PAGE_SIZE of memory (that's an arbitrary choice that's
* fast enough on the platforms we care about while minimizing
* wasted bootmem) and hand off chunks of it to callers.
*/
res = alloc_bootmem(chunk_size);
BUG_ON(!res);
prom_early_allocated += chunk_size;
memset(res, 0, chunk_size);
free_mem = chunk_size;
mem = res;
}
/* allocate from the local cache */
free_mem -= size;
res = mem;
mem += size;
return res;
}
static struct of_pdt_ops prom_olpc_ops __initdata = {
.nextprop = olpc_dt_nextprop,
.getproplen = olpc_dt_getproplen,
.getproperty = olpc_dt_getproperty,
.getchild = olpc_dt_getchild,
.getsibling = olpc_dt_getsibling,
.pkg2path = olpc_dt_pkg2path,
};
static phandle __init olpc_dt_finddevice(const char *path)
{
phandle node;
const void *args[] = { path };
void *res[] = { &node };
if (olpc_ofw("finddevice", args, res)) {
pr_err("olpc_dt: finddevice failed!\n");
return 0;
}
if ((s32) node == -1)
return 0;
return node;
}
static int __init olpc_dt_interpret(const char *words)
{
int result;
const void *args[] = { words };
void *res[] = { &result };
if (olpc_ofw("interpret", args, res)) {
pr_err("olpc_dt: interpret failed!\n");
return -1;
}
return result;
}
/*
* Extract board revision directly from OFW device tree.
* We can't use olpc_platform_info because that hasn't been set up yet.
*/
static u32 __init olpc_dt_get_board_revision(void)
{
phandle node;
__be32 rev;
int r;
node = olpc_dt_finddevice("/");
if (!node)
return 0;
r = olpc_dt_getproperty(node, "board-revision-int",
(char *) &rev, sizeof(rev));
if (r < 0)
return 0;
return be32_to_cpu(rev);
}
void __init olpc_dt_fixup(void)
{
int r;
char buf[64];
phandle node;
u32 board_rev;
node = olpc_dt_finddevice("/battery@0");
if (!node)
return;
/*
* If the battery node has a compatible property, we are running a new
* enough firmware and don't have fixups to make.
*/
r = olpc_dt_getproperty(node, "compatible", buf, sizeof(buf));
if (r > 0)
return;
pr_info("PROM DT: Old firmware detected, applying fixes\n");
/* Add olpc,xo1-battery compatible marker to battery node */
olpc_dt_interpret("\" /battery@0\" find-device"
" \" olpc,xo1-battery\" +compatible"
" device-end");
board_rev = olpc_dt_get_board_revision();
if (!board_rev)
return;
if (board_rev >= olpc_board_pre(0xd0)) {
/* XO-1.5: add dcon device */
olpc_dt_interpret("\" /pci/display@1\" find-device"
" new-device"
" \" dcon\" device-name \" olpc,xo1-dcon\" +compatible"
" finish-device device-end");
} else {
/* XO-1: add dcon device, mark RTC as olpc,xo1-rtc */
olpc_dt_interpret("\" /pci/display@1,1\" find-device"
" new-device"
" \" dcon\" device-name \" olpc,xo1-dcon\" +compatible"
" finish-device device-end"
" \" /rtc\" find-device"
" \" olpc,xo1-rtc\" +compatible"
" device-end");
}
}
void __init olpc_dt_build_devicetree(void)
{
phandle root;
if (!olpc_ofw_is_installed())
return;
olpc_dt_fixup();
root = olpc_dt_getsibling(0);
if (!root) {
pr_err("PROM: unable to get root node from OFW!\n");
return;
}
of_pdt_build_devicetree(root, &prom_olpc_ops);
pr_info("PROM DT: Built device tree with %u bytes of memory.\n",
prom_early_allocated);
}
/* A list of DT node/bus matches that we want to expose as platform devices */
static struct of_device_id __initdata of_ids[] = {
{ .compatible = "olpc,xo1-battery" },
{ .compatible = "olpc,xo1-dcon" },
{ .compatible = "olpc,xo1-rtc" },
{},
};
static int __init olpc_create_platform_devices(void)
{
if (machine_is_olpc())
return of_platform_bus_probe(NULL, of_ids, NULL);
else
return 0;
}
device_initcall(olpc_create_platform_devices);