[PATCH 9/9] x86: OLPC: add OLPC device-tree support

From: Andres Salomon <dilinger@queued.net>
To: devicetree-discuss@lists.ozlabs.org
Cc: sparclinux@vger.kernel.org, x86@kernel.org, tglx@linutronix.de,
	mingo@redhat.com, hpa@zytor.com, cjb@laptop.org,
	Mitch Bradley <wmb@laptop.org>,
	pgf@laptop.org, linux-kernel@vger.kernel.org,
	davem@davemloft.net, grant.likely@secretlab.ca,
	Stephen Neuendorffer <stephen.neuendorffer@xilinx.com>
Subject: [PATCH 9/9] x86: OLPC: add OLPC device-tree support
Date: Mon, 30 Aug 2010 00:07:51 -0400	[thread overview]
Message-ID: <20100830000751.2b845d05@debxo> (raw)
In-Reply-To: <20100829235100.6dcedcb8@debxo>


Make use of PROC_DEVICETREE to export the tree, and sparc's PROMTREE code to
call into OLPC's Open Firmware to build the tree.

This also adds an init hook to proc_device_tree_init so that we can ensure
the device tree has been built prior to the proc_root_init stuff attempting
to populate /proc/device-tree.

Signed-off-by: Andres Salomon <dilinger@queued.net>
---
 arch/x86/Kconfig                |    2 +
 arch/x86/include/asm/olpc_ofw.h |    4 +
 arch/x86/include/asm/prom.h     |    1 +
 arch/x86/kernel/Makefile        |    1 +
 arch/x86/kernel/olpc_ofw.c      |    8 ++
 arch/x86/kernel/olpc_prom.c     |  152 +++++++++++++++++++++++++++++++++++++++
 drivers/of/pdt.c                |    2 +
 fs/proc/proc_devtree.c          |    4 +
 include/linux/of_pdt.h          |    1 +
 9 files changed, 175 insertions(+), 0 deletions(-)
 create mode 100644 arch/x86/include/asm/prom.h
 create mode 100644 arch/x86/kernel/olpc_prom.c

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index cea0cd9..7d4ef72 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2069,6 +2069,8 @@ config OLPC_OPENFIRMWARE
 	bool "Support for OLPC's Open Firmware"
 	depends on !X86_64 && !X86_PAE
 	default y if OLPC
+	select OF
+	select OF_PROMTREE
 	help
 	  This option adds support for the implementation of Open Firmware
 	  that is used on the OLPC XO-1 Children's Machine.
diff --git a/arch/x86/include/asm/olpc_ofw.h b/arch/x86/include/asm/olpc_ofw.h
index 08fde47..13075df 100644
--- a/arch/x86/include/asm/olpc_ofw.h
+++ b/arch/x86/include/asm/olpc_ofw.h
@@ -28,4 +28,8 @@ static inline void setup_olpc_ofw_pgd(void) { }
 
 #endif /* !CONFIG_OLPC_OPENFIRMWARE */
 
+#ifdef CONFIG_PROC_DEVICETREE
+extern void olpc_prom_build_devicetree(void);
+#endif /* CONFIG_PROC_DEVICETREE */
+
 #endif /* _ASM_X86_OLPC_OFW_H */
diff --git a/arch/x86/include/asm/prom.h b/arch/x86/include/asm/prom.h
new file mode 100644
index 0000000..b4ec95f
--- /dev/null
+++ b/arch/x86/include/asm/prom.h
@@ -0,0 +1 @@
+/* dummy prom.h; here to make linux/of.h's #includes happy */
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 0925676..3d7e535 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -105,6 +105,7 @@ scx200-y			+= scx200_32.o
 
 obj-$(CONFIG_OLPC)		+= olpc.o
 obj-$(CONFIG_OLPC_OPENFIRMWARE)	+= olpc_ofw.o
+obj-$(CONFIG_PROC_DEVICETREE)	+= olpc_prom.o
 obj-$(CONFIG_X86_MRST)		+= mrst.o
 
 microcode-y				:= microcode_core.o
diff --git a/arch/x86/kernel/olpc_ofw.c b/arch/x86/kernel/olpc_ofw.c
index 3218aa7..6c4d243 100644
--- a/arch/x86/kernel/olpc_ofw.c
+++ b/arch/x86/kernel/olpc_ofw.c
@@ -1,5 +1,7 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_pdt.h>
 #include <linux/init.h>
 #include <asm/page.h>
 #include <asm/setup.h>
@@ -38,6 +40,12 @@ void __init setup_olpc_ofw_pgd(void)
 	/* implicit optimization barrier here due to uninline function return */
 
 	early_iounmap(base, sizeof(olpc_ofw_pgd) * PTRS_PER_PGD);
+
+#ifdef CONFIG_PROC_DEVICETREE
+	/* OFW set up succesfully; use it for the device tree */
+	of_pdt_init_devicetree = olpc_prom_build_devicetree;
+#endif
+
 }
 
 int __olpc_ofw(const char *name, int nr_args, const void **args, int nr_res,
diff --git a/arch/x86/kernel/olpc_prom.c b/arch/x86/kernel/olpc_prom.c
new file mode 100644
index 0000000..fb04d8a
--- /dev/null
+++ b/arch/x86/kernel/olpc_prom.c
@@ -0,0 +1,152 @@
+/*
+ * olpc_prom.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/module.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/of_pdt.h>
+#include <asm/olpc_ofw.h>
+
+static phandle __init olpc_prom_getsibling(phandle node)
+{
+	const void *args[] = { (void *)node };
+	void *res[] = { &node };
+
+	if (node == -1)
+		return 0;
+
+	if (olpc_ofw("peer", args, res) || node == -1)
+		return 0;
+
+	return node;
+}
+
+static phandle __init olpc_prom_getchild(phandle node)
+{
+	const void *args[] = { (void *)node };
+	void *res[] = { &node };
+
+	if (node == -1)
+		return 0;
+
+	if (olpc_ofw("child", args, res) || node == -1) {
+		pr_err("PROM: %s: fetching child failed!\n", __func__);
+		return 0;
+	}
+
+	return node;
+}
+
+static int __init olpc_prom_getproplen(phandle node, const char *prop)
+{
+	const void *args[] = { (void *)node, prop };
+	int len;
+	void *res[] = { &len };
+
+	if (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_prom_getproperty(phandle node, const char *prop,
+		char *buf, int bufsize)
+{
+	int plen;
+
+	plen = olpc_prom_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_prom_nextprop(phandle node, const char *prev, char *buf)
+{
+	const void *args[] = { (void *)node, prev, buf };
+	int success;
+	void *res[] = { &success };
+
+	buf[0] = '\0';
+
+	if (node == -1)
+		return -1;
+
+	if (olpc_ofw("nextprop", args, res) || success != 1)
+		return -1;
+
+	return 0;
+}
+
+static int __init olpc_prom_pkg2path(phandle node, char *buf,
+		const int buflen, int *len)
+{
+	const void *args[] = { (void *)node, buf, (void *)buflen };
+	void *res[] = { len };
+
+	if (node == -1)
+		return -1;
+
+	if (olpc_ofw("package-to-path", args, res) || *len < 1)
+		return -1;
+
+	return 0;
+}
+
+void * __init prom_early_alloc(unsigned long size)
+{
+	/* this is called late enough that we can alloc normally */
+	return kzalloc(size, GFP_KERNEL);
+}
+
+static struct of_pdt_ops prom_olpc_ops __initdata = {
+	.nextprop = olpc_prom_nextprop,
+	.getproplen = olpc_prom_getproplen,
+	.getproperty = olpc_prom_getproperty,
+	.getchild = olpc_prom_getchild,
+	.getsibling = olpc_prom_getsibling,
+	.pkg2path = olpc_prom_pkg2path,
+};
+
+void __init olpc_prom_build_devicetree(void)
+{
+	phandle root;
+
+	root = olpc_prom_getsibling(0);
+	if (root < 0) {
+		pr_err("PROM: unable to get root node from OFW!\n");
+		return;
+	}
+	of_pdt_build_devicetree(root, &prom_olpc_ops);
+}
diff --git a/drivers/of/pdt.c b/drivers/of/pdt.c
index 28295d0..07e3daa 100644
--- a/drivers/of/pdt.c
+++ b/drivers/of/pdt.c
@@ -29,6 +29,8 @@ static struct of_pdt_ops *of_pdt_prom_ops __initdata;
 void __initdata (*of_pdt_build_more)(struct device_node *dp,
 		struct device_node ***nextp);
 
+void __initdata (*of_pdt_init_devicetree)(void);
+
 #if defined(CONFIG_SPARC)
 unsigned int of_pdt_unique_id __initdata;
 
diff --git a/fs/proc/proc_devtree.c b/fs/proc/proc_devtree.c
index d9396a4..9779039 100644
--- a/fs/proc/proc_devtree.c
+++ b/fs/proc/proc_devtree.c
@@ -11,6 +11,7 @@
 #include <linux/stat.h>
 #include <linux/string.h>
 #include <linux/of.h>
+#include <linux/of_pdt.h>
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <asm/prom.h>
@@ -228,6 +229,9 @@ void __init proc_device_tree_init(void)
 {
 	struct device_node *root;
 
+	if (of_pdt_init_devicetree)
+		of_pdt_init_devicetree();
+
 	proc_device_tree = proc_mkdir("device-tree", NULL);
 	if (proc_device_tree == NULL)
 		return;
diff --git a/include/linux/of_pdt.h b/include/linux/of_pdt.h
index 9945e58..b4bd0ee 100644
--- a/include/linux/of_pdt.h
+++ b/include/linux/of_pdt.h
@@ -38,6 +38,7 @@ extern void *prom_early_alloc(unsigned long size);
 
 /* for building the device tree */
 extern void of_pdt_build_devicetree(phandle root_node, struct of_pdt_ops *ops);
+extern void (*of_pdt_init_devicetree)(void);
 
 extern void (*of_pdt_build_more)(struct device_node *dp,
 		struct device_node ***nextp);
-- 
1.5.6.5

