1 /* 2 * linux/arch/arm/kernel/devtree.c 3 * 4 * Copyright (C) 2009 Canonical Ltd. <jeremy.kerr@canonical.com> 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 */ 10 11 #include <linux/init.h> 12 #include <linux/module.h> 13 #include <linux/errno.h> 14 #include <linux/types.h> 15 #include <linux/bootmem.h> 16 #include <linux/memblock.h> 17 #include <linux/of.h> 18 #include <linux/of_fdt.h> 19 #include <linux/of_irq.h> 20 #include <linux/of_platform.h> 21 22 #include <asm/setup.h> 23 #include <asm/page.h> 24 #include <asm/mach/arch.h> 25 #include <asm/mach-types.h> 26 27 void __init early_init_dt_add_memory_arch(u64 base, u64 size) 28 { 29 arm_add_memory(base, size); 30 } 31 32 void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align) 33 { 34 return alloc_bootmem_align(size, align); 35 } 36 37 void __init arm_dt_memblock_reserve(void) 38 { 39 u64 *reserve_map, base, size; 40 41 if (!initial_boot_params) 42 return; 43 44 /* Reserve the dtb region */ 45 memblock_reserve(virt_to_phys(initial_boot_params), 46 be32_to_cpu(initial_boot_params->totalsize)); 47 48 /* 49 * Process the reserve map. This will probably overlap the initrd 50 * and dtb locations which are already reserved, but overlaping 51 * doesn't hurt anything 52 */ 53 reserve_map = ((void*)initial_boot_params) + 54 be32_to_cpu(initial_boot_params->off_mem_rsvmap); 55 while (1) { 56 base = be64_to_cpup(reserve_map++); 57 size = be64_to_cpup(reserve_map++); 58 if (!size) 59 break; 60 memblock_reserve(base, size); 61 } 62 } 63 64 /** 65 * setup_machine_fdt - Machine setup when an dtb was passed to the kernel 66 * @dt_phys: physical address of dt blob 67 * 68 * If a dtb was passed to the kernel in r2, then use it to choose the 69 * correct machine_desc and to setup the system. 70 */ 71 struct machine_desc * __init setup_machine_fdt(unsigned int dt_phys) 72 { 73 struct boot_param_header *devtree; 74 struct machine_desc *mdesc, *mdesc_best = NULL; 75 unsigned int score, mdesc_score = ~1; 76 unsigned long dt_root; 77 const char *model; 78 79 if (!dt_phys) 80 return NULL; 81 82 devtree = phys_to_virt(dt_phys); 83 84 /* check device tree validity */ 85 if (be32_to_cpu(devtree->magic) != OF_DT_HEADER) 86 return NULL; 87 88 /* Search the mdescs for the 'best' compatible value match */ 89 initial_boot_params = devtree; 90 dt_root = of_get_flat_dt_root(); 91 for_each_machine_desc(mdesc) { 92 score = of_flat_dt_match(dt_root, mdesc->dt_compat); 93 if (score > 0 && score < mdesc_score) { 94 mdesc_best = mdesc; 95 mdesc_score = score; 96 } 97 } 98 if (!mdesc_best) { 99 const char *prop; 100 long size; 101 102 early_print("\nError: unrecognized/unsupported " 103 "device tree compatible list:\n[ "); 104 105 prop = of_get_flat_dt_prop(dt_root, "compatible", &size); 106 while (size > 0) { 107 early_print("'%s' ", prop); 108 size -= strlen(prop) + 1; 109 prop += strlen(prop) + 1; 110 } 111 early_print("]\n\n"); 112 113 dump_machine_table(); /* does not return */ 114 } 115 116 model = of_get_flat_dt_prop(dt_root, "model", NULL); 117 if (!model) 118 model = of_get_flat_dt_prop(dt_root, "compatible", NULL); 119 if (!model) 120 model = "<unknown>"; 121 pr_info("Machine: %s, model: %s\n", mdesc_best->name, model); 122 123 /* Retrieve various information from the /chosen node */ 124 of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line); 125 /* Initialize {size,address}-cells info */ 126 of_scan_flat_dt(early_init_dt_scan_root, NULL); 127 /* Setup memory, calling early_init_dt_add_memory_arch */ 128 of_scan_flat_dt(early_init_dt_scan_memory, NULL); 129 130 /* Change machine number to match the mdesc we're using */ 131 __machine_arch_type = mdesc_best->nr; 132 133 return mdesc_best; 134 } 135 136 /** 137 * irq_create_of_mapping - Hook to resolve OF irq specifier into a Linux irq# 138 * 139 * Currently the mapping mechanism is trivial; simple flat hwirq numbers are 140 * mapped 1:1 onto Linux irq numbers. Cascaded irq controllers are not 141 * supported. 142 */ 143 unsigned int irq_create_of_mapping(struct device_node *controller, 144 const u32 *intspec, unsigned int intsize) 145 { 146 return intspec[0]; 147 } 148 EXPORT_SYMBOL_GPL(irq_create_of_mapping); 149