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author | Vineet Gupta <vgupta@synopsys.com> | 2013-01-22 11:30:52 (GMT) |
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committer | Vineet Gupta <vgupta@synopsys.com> | 2013-02-15 17:45:55 (GMT) |
commit | 999159a5381bff3bd6f688c5d20fbec9d8789e53 (patch) | |
tree | d54af343e2fa905b3d97d9dd87d763a43b256067 /arch/arc/kernel | |
parent | ee36d1722112f33725ec1a7fc02f6c46e630fd27 (diff) | |
download | linux-fsl-qoriq-999159a5381bff3bd6f688c5d20fbec9d8789e53.tar.xz |
ARC: [DeviceTree] Basic support
This is minimal infrastructure needed for devicetree work.
It uses an a sample "skeleton" devicetree - embedded in kernel image -
to print the board, manufacturer by parsing the top-level "compatible"
string.
As of now we don't need any additional "board" specific "machine_desc".
TODO: support interpreting the command line as boot-loader passed dtb
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: devicetree-discuss@lists.ozlabs.org
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: James Hogan <james.hogan@imgtec.com>
Reviewed-by: Rob Herring <rob.herring@calxeda.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Diffstat (limited to 'arch/arc/kernel')
-rw-r--r-- | arch/arc/kernel/Makefile | 1 | ||||
-rw-r--r-- | arch/arc/kernel/devtree.c | 64 | ||||
-rw-r--r-- | arch/arc/kernel/setup.c | 9 |
3 files changed, 74 insertions, 0 deletions
diff --git a/arch/arc/kernel/Makefile b/arch/arc/kernel/Makefile index 6d83431..c9ec066 100644 --- a/arch/arc/kernel/Makefile +++ b/arch/arc/kernel/Makefile @@ -7,6 +7,7 @@ obj-y := arcksyms.o setup.o irq.o time.o reset.o ptrace.o entry.o process.o obj-y += signal.o traps.o sys.o troubleshoot.o stacktrace.o clk.o +obj-y += devtree.o obj-$(CONFIG_ARC_FPU_SAVE_RESTORE) += fpu.o CFLAGS_fpu.o += -mdpfp diff --git a/arch/arc/kernel/devtree.c b/arch/arc/kernel/devtree.c new file mode 100644 index 0000000..48e157e --- /dev/null +++ b/arch/arc/kernel/devtree.c @@ -0,0 +1,64 @@ +/* + * Copyright (C) 2012 Synopsys, Inc. (www.synopsys.com) + * + * Based on reduced version of METAG + * + * 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/reboot.h> +#include <linux/memblock.h> +#include <linux/of.h> +#include <linux/of_fdt.h> +#include <asm/prom.h> + +/* called from unflatten_device_tree() to bootstrap devicetree itself */ +void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align) +{ + return __va(memblock_alloc(size, align)); +} + +/** + * setup_machine_fdt - Machine setup when an dtb was passed to the kernel + * @dt: virtual address pointer to dt blob + * + * If a dtb was passed to the kernel, then use it to choose the correct + * machine_desc and to setup the system. + */ +int __init setup_machine_fdt(void *dt) +{ + struct boot_param_header *devtree = dt; + unsigned long dt_root; + char *model, *compat; + char manufacturer[16]; + + /* check device tree validity */ + if (be32_to_cpu(devtree->magic) != OF_DT_HEADER) + return 1; + + /* Search the mdescs for the 'best' compatible value match */ + initial_boot_params = devtree; + dt_root = of_get_flat_dt_root(); + + /* compat = "<manufacturer>,<model>" */ + compat = of_get_flat_dt_prop(dt_root, "compatible", NULL); + if (!compat) + compat = "<unknown>"; + + model = strchr(compat, ','); + if (model) + model++; + + strlcpy(manufacturer, compat, model ? model - compat : strlen(compat)); + + pr_info("Board \"%s\" from %s (Manufacturer)\n", model, manufacturer); + + /* Retrieve various information from the /chosen node */ + of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line); + + return 0; +} diff --git a/arch/arc/kernel/setup.c b/arch/arc/kernel/setup.c index 82ac206..27aebd6 100644 --- a/arch/arc/kernel/setup.c +++ b/arch/arc/kernel/setup.c @@ -13,6 +13,8 @@ #include <linux/console.h> #include <linux/module.h> #include <linux/cpu.h> +#include <linux/of_fdt.h> +#include <asm/sections.h> #include <asm/arcregs.h> #include <asm/tlb.h> #include <asm/cache.h> @@ -20,6 +22,7 @@ #include <asm/page.h> #include <asm/irq.h> #include <asm/arcregs.h> +#include <asm/prom.h> #define FIX_PTR(x) __asm__ __volatile__(";" : "+r"(x)) @@ -57,6 +60,8 @@ void __init __attribute__((weak)) arc_platform_early_init(void) void __init setup_arch(char **cmdline_p) { + int rc; + #ifdef CONFIG_CMDLINE_UBOOT /* Make sure that a whitespace is inserted before */ strlcat(command_line, " ", sizeof(command_line)); @@ -71,6 +76,8 @@ void __init setup_arch(char **cmdline_p) strlcpy(boot_command_line, command_line, COMMAND_LINE_SIZE); *cmdline_p = command_line; + rc = setup_machine_fdt(__dtb_start); + /* To force early parsing of things like mem=xxx */ parse_early_param(); @@ -81,6 +88,8 @@ void __init setup_arch(char **cmdline_p) setup_arch_memory(); + unflatten_device_tree(); + /* Can be issue if someone passes cmd line arg "ro" * But that is unlikely so keeping it as it is */ |