2 * OLPC-specific OFW device tree support code.
4 * Paul Mackerras August 1996.
5 * Copyright (C) 1996-2005 Paul Mackerras.
7 * Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
8 * {engebret|bergner}@us.ibm.com
10 * Adapted for sparc by David S. Miller davem@davemloft.net
11 * Adapted for x86/OLPC by Andres Salomon <dilinger@queued.net>
13 * This program is free software; you can redistribute it and/or
14 * modify it under the terms of the GNU General Public License
15 * as published by the Free Software Foundation; either version
16 * 2 of the License, or (at your option) any later version.
19 #include <linux/kernel.h>
20 #include <linux/bootmem.h>
22 #include <linux/of_platform.h>
23 #include <linux/of_pdt.h>
25 #include <asm/olpc_ofw.h>
27 static phandle __init olpc_dt_getsibling(phandle node)
29 const void *args[] = { (void *)node };
30 void *res[] = { &node };
35 if (olpc_ofw("peer", args, res) || (s32)node == -1)
41 static phandle __init olpc_dt_getchild(phandle node)
43 const void *args[] = { (void *)node };
44 void *res[] = { &node };
49 if (olpc_ofw("child", args, res) || (s32)node == -1) {
50 pr_err("PROM: %s: fetching child failed!\n", __func__);
57 static int __init olpc_dt_getproplen(phandle node, const char *prop)
59 const void *args[] = { (void *)node, prop };
61 void *res[] = { &len };
66 if (olpc_ofw("getproplen", args, res)) {
67 pr_err("PROM: %s: getproplen failed!\n", __func__);
74 static int __init olpc_dt_getproperty(phandle node, const char *prop,
75 char *buf, int bufsize)
79 plen = olpc_dt_getproplen(node, prop);
80 if (plen > bufsize || plen < 1) {
83 const void *args[] = { (void *)node, prop, buf, (void *)plen };
84 void *res[] = { &plen };
86 if (olpc_ofw("getprop", args, res)) {
87 pr_err("PROM: %s: getprop failed!\n", __func__);
95 static int __init olpc_dt_nextprop(phandle node, char *prev, char *buf)
97 const void *args[] = { (void *)node, prev, buf };
99 void *res[] = { &success };
106 if (olpc_ofw("nextprop", args, res) || success != 1)
112 static int __init olpc_dt_pkg2path(phandle node, char *buf,
113 const int buflen, int *len)
115 const void *args[] = { (void *)node, buf, (void *)buflen };
116 void *res[] = { len };
121 if (olpc_ofw("package-to-path", args, res) || *len < 1)
127 static unsigned int prom_early_allocated __initdata;
129 void * __init prom_early_alloc(unsigned long size)
132 static size_t free_mem;
135 if (free_mem < size) {
136 const size_t chunk_size = max(PAGE_SIZE, size);
139 * To mimimize the number of allocations, grab at least
140 * PAGE_SIZE of memory (that's an arbitrary choice that's
141 * fast enough on the platforms we care about while minimizing
142 * wasted bootmem) and hand off chunks of it to callers.
144 res = alloc_bootmem(chunk_size);
146 prom_early_allocated += chunk_size;
147 memset(res, 0, chunk_size);
148 free_mem = chunk_size;
152 /* allocate from the local cache */
159 static struct of_pdt_ops prom_olpc_ops __initdata = {
160 .nextprop = olpc_dt_nextprop,
161 .getproplen = olpc_dt_getproplen,
162 .getproperty = olpc_dt_getproperty,
163 .getchild = olpc_dt_getchild,
164 .getsibling = olpc_dt_getsibling,
165 .pkg2path = olpc_dt_pkg2path,
168 static phandle __init olpc_dt_finddevice(const char *path)
171 const void *args[] = { path };
172 void *res[] = { &node };
174 if (olpc_ofw("finddevice", args, res)) {
175 pr_err("olpc_dt: finddevice failed!\n");
179 if ((s32) node == -1)
185 static int __init olpc_dt_interpret(const char *words)
188 const void *args[] = { words };
189 void *res[] = { &result };
191 if (olpc_ofw("interpret", args, res)) {
192 pr_err("olpc_dt: interpret failed!\n");
200 * Extract board revision directly from OFW device tree.
201 * We can't use olpc_platform_info because that hasn't been set up yet.
203 static u32 __init olpc_dt_get_board_revision(void)
209 node = olpc_dt_finddevice("/");
213 r = olpc_dt_getproperty(node, "board-revision-int",
214 (char *) &rev, sizeof(rev));
218 return be32_to_cpu(rev);
221 void __init olpc_dt_fixup(void)
228 node = olpc_dt_finddevice("/battery@0");
233 * If the battery node has a compatible property, we are running a new
234 * enough firmware and don't have fixups to make.
236 r = olpc_dt_getproperty(node, "compatible", buf, sizeof(buf));
240 pr_info("PROM DT: Old firmware detected, applying fixes\n");
242 /* Add olpc,xo1-battery compatible marker to battery node */
243 olpc_dt_interpret("\" /battery@0\" find-device"
244 " \" olpc,xo1-battery\" +compatible"
247 board_rev = olpc_dt_get_board_revision();
251 if (board_rev >= olpc_board_pre(0xd0)) {
252 /* XO-1.5: add dcon device */
253 olpc_dt_interpret("\" /pci/display@1\" find-device"
255 " \" dcon\" device-name \" olpc,xo1-dcon\" +compatible"
256 " finish-device device-end");
258 /* XO-1: add dcon device, mark RTC as olpc,xo1-rtc */
259 olpc_dt_interpret("\" /pci/display@1,1\" find-device"
261 " \" dcon\" device-name \" olpc,xo1-dcon\" +compatible"
262 " finish-device device-end"
263 " \" /rtc\" find-device"
264 " \" olpc,xo1-rtc\" +compatible"
269 void __init olpc_dt_build_devicetree(void)
273 if (!olpc_ofw_is_installed())
278 root = olpc_dt_getsibling(0);
280 pr_err("PROM: unable to get root node from OFW!\n");
283 of_pdt_build_devicetree(root, &prom_olpc_ops);
285 pr_info("PROM DT: Built device tree with %u bytes of memory.\n",
286 prom_early_allocated);
289 /* A list of DT node/bus matches that we want to expose as platform devices */
290 static struct of_device_id __initdata of_ids[] = {
291 { .compatible = "olpc,xo1-battery" },
292 { .compatible = "olpc,xo1-dcon" },
293 { .compatible = "olpc,xo1-rtc" },
297 static int __init olpc_create_platform_devices(void)
299 if (machine_is_olpc())
300 return of_platform_bus_probe(NULL, of_ids, NULL);
304 device_initcall(olpc_create_platform_devices);