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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* 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>
*/
#include <linux/kernel.h>
#include <linux/memblock.h>
#include <linux/of.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 = memblock_alloc(chunk_size, SMP_CACHE_BYTES);
if (!res)
panic("%s: Failed to allocate %zu bytes\n", __func__,
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);
}
static int __init olpc_dt_compatible_match(phandle node, const char *compat)
{
char buf[64], *p;
int plen, len;
plen = olpc_dt_getproperty(node, "compatible", buf, sizeof(buf));
if (plen <= 0)
return 0;
len = strlen(compat);
for (p = buf; p < buf + plen; p += strlen(p) + 1) {
if (strcmp(p, compat) == 0)
return 1;
}
return 0;
}
void __init olpc_dt_fixup(void)
{
phandle node;
u32 board_rev;
node = olpc_dt_finddevice("/battery@0");
if (!node)
return;
board_rev = olpc_dt_get_board_revision();
if (!board_rev)
return;
if (board_rev >= olpc_board_pre(0xd0)) {
/* XO-1.5 */
if (olpc_dt_compatible_match(node, "olpc,xo1.5-battery"))
return;
/* Add olpc,xo1.5-battery compatible marker to battery node */
olpc_dt_interpret("\" /battery@0\" find-device");
olpc_dt_interpret(" \" olpc,xo1.5-battery\" +compatible");
olpc_dt_interpret("device-end");
if (olpc_dt_compatible_match(node, "olpc,xo1-battery")) {
/*
* If we have a olpc,xo1-battery compatible, then we're
* running a new enough firmware that already has
* the dcon node.
*/
return;
}
/* Add dcon device */
olpc_dt_interpret("\" /pci/display@1\" find-device");
olpc_dt_interpret(" new-device");
olpc_dt_interpret(" \" dcon\" device-name");
olpc_dt_interpret(" \" olpc,xo1-dcon\" +compatible");
olpc_dt_interpret(" finish-device");
olpc_dt_interpret("device-end");
} else {
/* XO-1 */
if (olpc_dt_compatible_match(node, "olpc,xo1-battery")) {
/*
* If we have a olpc,xo1-battery compatible, then we're
* running a new enough firmware that already has
* the dcon and RTC nodes.
*/
return;
}
/* Add dcon device, mark RTC as olpc,xo1-rtc */
olpc_dt_interpret("\" /pci/display@1,1\" find-device");
olpc_dt_interpret(" new-device");
olpc_dt_interpret(" \" dcon\" device-name");
olpc_dt_interpret(" \" olpc,xo1-dcon\" +compatible");
olpc_dt_interpret(" finish-device");
olpc_dt_interpret("device-end");
olpc_dt_interpret("\" /rtc\" find-device");
olpc_dt_interpret(" \" olpc,xo1-rtc\" +compatible");
olpc_dt_interpret("device-end");
}
/* Add olpc,xo1-battery compatible marker to battery node */
olpc_dt_interpret("\" /battery@0\" find-device");
olpc_dt_interpret(" \" olpc,xo1-battery\" +compatible");
olpc_dt_interpret("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);
}