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RE: [RFC PATCH 1/2] The Device Tree Patch for MIPS

To: <linux-mips@linux-mips.org>
Subject: RE: [RFC PATCH 1/2] The Device Tree Patch for MIPS
From: "Dezhong Diao (dediao)" <dediao@cisco.com>
Date: Mon, 10 May 2010 16:34:30 -0500
Authentication-results: rtp-iport-2.cisco.com; dkim=neutral (message not signed) header.i=none
Cc: "David VomLehn (dvomlehn)" <dvomlehn@cisco.com>, "Tony Colclough (colclot)" <colclot@cisco.com>, "Grant Likely" <grant.likely@secretlab.ca>
Original-recipient: rfc822;linux-mips@linux-mips.org
Sender: linux-mips-bounce@linux-mips.org
Thread-index: AcrwiE2Kxdp67lxkSEmhUR3BghfpGAAAArHw
Thread-topic: [RFC PATCH 1/2] The Device Tree Patch for MIPS
Add common device tree support for MIPS.


---
 arch/mips/Kconfig                   |   20 ++++
 arch/mips/include/asm/of_device.h   |    3 +
 arch/mips/include/asm/of_platform.h |    9 ++
 arch/mips/include/asm/prom.h        |   64 ++++++++++++++
 arch/mips/kernel/Makefile           |    2 +
 arch/mips/kernel/prom.c             |  164
+++++++++++++++++++++++++++++++++++
 arch/mips/kernel/setup.c            |    2 +
 7 files changed, 264 insertions(+), 0 deletions(-)  create mode 100644
arch/mips/include/asm/of_device.h  create mode 100644
arch/mips/include/asm/of_platform.h
 create mode 100644 arch/mips/include/asm/prom.h  create mode 100644
arch/mips/kernel/prom.c

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index
29e8692..55d8331 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -2052,6 +2052,26 @@ config SECCOMP
 
          If unsure, say Y. Only embedded should say N here.
 
+config OF
+       bool "Device tree support"
+       select OF_FLATTREE
+       help
+         Support for OpenFirmware-style device trees
+
+config PROC_DEVICETREE
+       bool "Support for device tree in /proc"
+       depends on PROC_FS && OF
+       help
+         This option adds a device-tree directory under /proc which
contains
+         an image of the device tree that the kernel copies from Open
+         Firmware or other boot firmware. If unsure, say Y here.
+
+config ARCH_HAS_DEVTREE_MEM
+       bool "Support user-defined memory scan function in device tree"
+       depends on OF
+       help
+         The user has a customized function to parse memory nodes.
+
 endmenu
 
 config LOCKDEP_SUPPORT
diff --git a/arch/mips/include/asm/of_device.h
b/arch/mips/include/asm/of_device.h
new file mode 100644
index 0000000..7a83477
--- /dev/null
+++ b/arch/mips/include/asm/of_device.h
@@ -0,0 +1,3 @@
+#ifndef _ASM_MIPS_OF_DEVICE_H
+#define _ASM_MIPS_OF_DEVICE_H
+#endif /* _ASM_MIPS_OF_DEVICE_H */
diff --git a/arch/mips/include/asm/of_platform.h
b/arch/mips/include/asm/of_platform.h
new file mode 100644
index 0000000..7a33827
--- /dev/null
+++ b/arch/mips/include/asm/of_platform.h
@@ -0,0 +1,9 @@
+#ifndef _ASM_MIPS_OF_PLATFORM_H
+#define _ASM_MIPS_OF_PLATFORM_H
+
+static inline void of_device_make_bus_id(struct device *dev) {
+       __of_device_make_bus_id(dev);
+}
+
+#endif /* _ASM_MIPS_OF_PLATFORM_H */
diff --git a/arch/mips/include/asm/prom.h b/arch/mips/include/asm/prom.h
new file mode 100644 index 0000000..e72b0df
--- /dev/null
+++ b/arch/mips/include/asm/prom.h
@@ -0,0 +1,64 @@
+/*
+ *  arch/mips/include/asm/prom.h
+ *
+ *  Copyright (C) 2010 Cisco Systems Inc. <dediao@cisco.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+#ifndef __ASM_MIPS_PROM_H
+#define __ASM_MIPS_PROM_H
+
+#ifdef CONFIG_OF
+#include <linux/init.h>
+
+#include <asm/setup.h>
+#include <asm/irq.h>
+#include <asm/bootinfo.h>
+
+/* _ALIGN expects upwards alignment */
+#define _ALIGN(addr, size)     (((addr) + ((size) - 1)) & (~((size) -
1)))
+
+/* which is compatible with the flattened device tree (FDT) */ #define 
+cmd_line arcs_cmdline
+
+/*
+ * Use this value to indicate lack of interrupt
+ * capability
+ */
+#ifndef NO_IRQ
+#define NO_IRQ  ((unsigned int)(-1))
+#endif
+
+static inline unsigned long pci_address_to_pio(phys_addr_t address) {
+       return (unsigned long)-1;
+}
+
+struct device_node;
+
+static inline int of_node_to_nid(struct device_node *device) {
+       return 0;
+}
+
+static inline void __init early_init_dt_scan_chosen_arch(unsigned long
node)
+{
+}
+
+extern int __init early_init_dt_scan_memory_arch(unsigned long node,
+       const char *uname, int depth, void *data);
+
+extern int __init reserve_mem_mach(unsigned long addr, unsigned long
size);
+extern void __init free_mem_mach(unsigned long addr, unsigned long
size);
+
+extern void __init device_tree_init(void); #else /* CONFIG_OF */ static

+inline void __init device_tree_init(void) { } #endif /* CONFIG_OF */
+
+#endif /* _ASM_MIPS_PROM_H */
diff --git a/arch/mips/kernel/Makefile b/arch/mips/kernel/Makefile index
ef20957..4b10545 100644
--- a/arch/mips/kernel/Makefile
+++ b/arch/mips/kernel/Makefile
@@ -95,6 +95,8 @@ obj-$(CONFIG_KEXEC)           += machine_kexec.o
relocate_kernel.o
 obj-$(CONFIG_EARLY_PRINTK)     += early_printk.o
 obj-$(CONFIG_SPINLOCK_TEST)    += spinlock_test.o
 
+obj-$(CONFIG_OF)               += prom.o
+
 CFLAGS_cpu-bugs64.o    = $(shell if $(CC) $(KBUILD_CFLAGS) -Wa,-mdaddi
-c -o /dev/null -xc /dev/null >/dev/null 2>&1; then echo
"-DHAVE_AS_SET_DADDI"; fi)
 
 obj-$(CONFIG_HAVE_STD_PC_SERIAL_PORT)  += 8250-platform.o
diff --git a/arch/mips/kernel/prom.c b/arch/mips/kernel/prom.c new file
mode 100644 index 0000000..2cbd43f
--- /dev/null
+++ b/arch/mips/kernel/prom.c
@@ -0,0 +1,164 @@
+/*
+ *  linux/arch/mips/kernel/prom.c
+ *
+ *  Copyright (C) 2010 Cisco Systems Inc. <dediao@cisco.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/bootmem.h>
+#include <linux/initrd.h>
+#include <linux/debugfs.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
+
+#include <asm/page.h>
+#include <asm/prom.h>
+
+/*
+ * The list of OF IDs below is used for matching bus types in the
+ * system whose devices are to be exposed as of_platform_devices.
+ *
+ * This is the default list valid for most platforms. This file
provides
+ * functions who can take an explicit list if necessary though
+ *
+ * The search is always performed recursively looking for children of
+ * the provided device_node and recursively if such a children matches
+ * a bus type in the list
+ */
+const struct of_device_id of_default_bus_ids[] = {
+       {},
+};
+
+#ifndef CONFIG_ARCH_HAS_DEVTREE_MEM
+int __init early_init_dt_scan_memory_arch(unsigned long node,
+                                         const char *uname, int depth,
+                                         void *data)
+{
+       return early_init_dt_scan_memory(node, uname, depth, data); }
+
+void __init early_init_dt_add_memory_arch(u64 base, u64 size) {
+       return add_memory_region(base, size, BOOT_MEM_RAM); }
+
+int __init reserve_mem_mach(unsigned long addr, unsigned long size) {
+       return reserve_bootmem(addr, size, BOOTMEM_DEFAULT); }
+
+void __init free_mem_mach(unsigned long addr, unsigned long size) {
+       return free_bootmem(addr, size);
+}
+#endif
+
+u64 __init early_init_dt_alloc_memory_arch(u64 size, u64 align) {
+       return virt_to_phys(
+               __alloc_bootmem(size, align, __pa(MAX_DMA_ADDRESS))
+               );
+}
+
+#ifdef CONFIG_BLK_DEV_INITRD
+void __init early_init_dt_setup_initrd_arch(unsigned long start,
+                                           unsigned long end)
+{
+       initrd_start = (unsigned long)__va(start);
+       initrd_end = (unsigned long)__va(end);
+       initrd_below_start_ok = 1;
+}
+#endif
+
+/*
+ * Interrupt remapper
+ */
+struct device_node *of_irq_find_parent_by_phandle(phandle p) {
+       return of_find_node_by_phandle(p);
+}
+
+int of_irq_map_one(struct device_node *device,
+                  int index, struct of_irq *out_irq) {
+       return __of_irq_map_one(device, index, out_irq); } 
+EXPORT_SYMBOL_GPL(of_irq_map_one);
+
+/*
+ * irq_create_of_mapping - Hook to resolve OF irq specifier into a
Linux irq#
+ *
+ * Currently the mapping mechanism is trivial; simple flat hwirq
numbers are
+ * mapped 1:1 onto Linux irq numbers.  Cascaded irq controllers are not
+ * supported.
+ */
+unsigned int irq_create_of_mapping(struct device_node *controller,
+                                  const u32 *intspec, unsigned int
intsize)
+{
+       return intspec[0];
+}
+EXPORT_SYMBOL_GPL(irq_create_of_mapping);
+
+void __init early_init_devtree(void *params) {
+       /* Setup flat device-tree pointer */
+       initial_boot_params = params;
+
+       /* Retrieve various informations from the /chosen node of the
+        * device-tree, including the platform type, initrd location and
+        * size, and more ...
+        */
+       of_scan_flat_dt(early_init_dt_scan_chosen, NULL);
+
+       /* Scan memory nodes */
+       of_scan_flat_dt(early_init_dt_scan_root, NULL);
+       of_scan_flat_dt(early_init_dt_scan_memory_arch, NULL); }
+
+void __init device_tree_init(void)
+{
+       unsigned long base, size;
+
+       if (!initial_boot_params)
+               return;
+
+       base = virt_to_phys((void *)initial_boot_params);
+       size = initial_boot_params->totalsize;
+
+       /* Before we do anything, lets reserve the dt blob */
+       reserve_mem_mach(base, size);
+
+       unflatten_device_tree();
+
+       /* free the space reserved for the dt blob */
+       free_mem_mach(base, size);
+}
+
+#if defined(CONFIG_DEBUG_FS) && defined(DEBUG) static struct 
+debugfs_blob_wrapper flat_dt_blob;
+
+static int __init export_flat_device_tree(void) {
+       struct dentry *d;
+
+       flat_dt_blob.data = initial_boot_params;
+       flat_dt_blob.size = initial_boot_params->totalsize;
+
+       d = debugfs_create_blob("flat-device-tree", S_IFREG | S_IRUSR,
+                               powerpc_debugfs_root, &flat_dt_blob);
+       if (!d)
+               return 1;
+
+       return 0;
+}
+__initcall(export_flat_device_tree);
+#endif
diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c index
f9513f9..55a85e4 100644
--- a/arch/mips/kernel/setup.c
+++ b/arch/mips/kernel/setup.c
@@ -31,6 +31,7 @@
 #include <asm/setup.h>
 #include <asm/smp-ops.h>
 #include <asm/system.h>
+#include <asm/prom.h>
 
 struct cpuinfo_mips cpu_data[NR_CPUS] __read_mostly;
 
@@ -487,6 +488,7 @@ static void __init arch_mem_init(char **cmdline_p)
        }
 
        bootmem_init();
+       device_tree_init();
        sparse_init();
        paging_init();
 }
--
1.6.0.6

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