diff options
Diffstat (limited to 'arch/arc/kernel/devtree.c')
-rw-r--r-- | arch/arc/kernel/devtree.c | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/arch/arc/kernel/devtree.c b/arch/arc/kernel/devtree.c new file mode 100644 index 0000000..bdee3a8 --- /dev/null +++ b/arch/arc/kernel/devtree.c @@ -0,0 +1,123 @@ +/* + * 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> +#include <asm/clk.h> +#include <asm/mach_desc.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. + */ +struct machine_desc * __init setup_machine_fdt(void *dt) +{ + struct boot_param_header *devtree = dt; + struct machine_desc *mdesc = NULL, *mdesc_best = NULL; + unsigned int score, mdesc_score = ~1; + unsigned long dt_root; + const char *model, *compat; + void *clk; + char manufacturer[16]; + unsigned long len; + + /* check device tree validity */ + if (be32_to_cpu(devtree->magic) != OF_DT_HEADER) + return NULL; + + initial_boot_params = devtree; + dt_root = of_get_flat_dt_root(); + + /* + * The kernel could be multi-platform enabled, thus could have many + * "baked-in" machine descriptors. Search thru all for the best + * "compatible" string match. + */ + for_each_machine_desc(mdesc) { + score = of_flat_dt_match(dt_root, mdesc->dt_compat); + if (score > 0 && score < mdesc_score) { + mdesc_best = mdesc; + mdesc_score = score; + } + } + if (!mdesc_best) { + const char *prop; + long size; + + pr_err("\n unrecognized device tree list:\n[ "); + + prop = of_get_flat_dt_prop(dt_root, "compatible", &size); + if (prop) { + while (size > 0) { + printk("'%s' ", prop); + size -= strlen(prop) + 1; + prop += strlen(prop) + 1; + } + } + printk("]\n\n"); + + machine_halt(); + } + + /* compat = "<manufacturer>,<model>" */ + compat = mdesc_best->dt_compat[0]; + + 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); + + /* Initialize {size,address}-cells info */ + of_scan_flat_dt(early_init_dt_scan_root, NULL); + + /* Setup memory, calling early_init_dt_add_memory_arch */ + of_scan_flat_dt(early_init_dt_scan_memory, NULL); + + clk = of_get_flat_dt_prop(dt_root, "clock-frequency", &len); + if (clk) + arc_set_core_freq(of_read_ulong(clk, len/4)); + + return mdesc_best; +} + +/* + * Copy the flattened DT out of .init since unflattening doesn't copy strings + * and the normal DT APIs refs them from orig flat DT + */ +void __init copy_devtree(void) +{ + void *alloc = early_init_dt_alloc_memory_arch( + be32_to_cpu(initial_boot_params->totalsize), 64); + if (alloc) { + memcpy(alloc, initial_boot_params, + be32_to_cpu(initial_boot_params->totalsize)); + initial_boot_params = alloc; + } +} |