1 files changed, 326 insertions, 0 deletions
diff --git a/arch/x86/platform/olpc/olpc_dt.c b/arch/x86/platform/olpc/olpc_dt.c
new file mode 100644
index 000000000..75e3319e8
--- /dev/null
+++ b/arch/x86/platform/olpc/olpc_dt.c
@@ -0,0 +1,326 @@
+// 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 minimize 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);
+}