1 /* 2 * Copyright (C) 2012 Synopsys, Inc. (www.synopsys.com) 3 * 4 * Based on reduced version of METAG 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 12 #include <linux/init.h> 13 #include <linux/reboot.h> 14 #include <linux/memblock.h> 15 #include <linux/of.h> 16 #include <linux/of_fdt.h> 17 #include <asm/prom.h> 18 #include <asm/clk.h> 19 #include <asm/mach_desc.h> 20 21 /** 22 * setup_machine_fdt - Machine setup when an dtb was passed to the kernel 23 * @dt: virtual address pointer to dt blob 24 * 25 * If a dtb was passed to the kernel, then use it to choose the correct 26 * machine_desc and to setup the system. 27 */ 28 struct machine_desc * __init setup_machine_fdt(void *dt) 29 { 30 struct boot_param_header *devtree = dt; 31 struct machine_desc *mdesc = NULL, *mdesc_best = NULL; 32 unsigned int score, mdesc_score = ~1; 33 unsigned long dt_root; 34 const char *model, *compat; 35 void *clk; 36 char manufacturer[16]; 37 unsigned long len; 38 39 /* check device tree validity */ 40 if (be32_to_cpu(devtree->magic) != OF_DT_HEADER) 41 return NULL; 42 43 initial_boot_params = devtree; 44 dt_root = of_get_flat_dt_root(); 45 46 /* 47 * The kernel could be multi-platform enabled, thus could have many 48 * "baked-in" machine descriptors. Search thru all for the best 49 * "compatible" string match. 50 */ 51 for_each_machine_desc(mdesc) { 52 score = of_flat_dt_match(dt_root, mdesc->dt_compat); 53 if (score > 0 && score < mdesc_score) { 54 mdesc_best = mdesc; 55 mdesc_score = score; 56 } 57 } 58 if (!mdesc_best) { 59 const char *prop; 60 long size; 61 62 pr_err("\n unrecognized device tree list:\n[ "); 63 64 prop = of_get_flat_dt_prop(dt_root, "compatible", &size); 65 if (prop) { 66 while (size > 0) { 67 printk("'%s' ", prop); 68 size -= strlen(prop) + 1; 69 prop += strlen(prop) + 1; 70 } 71 } 72 printk("]\n\n"); 73 74 machine_halt(); 75 } 76 77 /* compat = "<manufacturer>,<model>" */ 78 compat = mdesc_best->dt_compat[0]; 79 80 model = strchr(compat, ','); 81 if (model) 82 model++; 83 84 strlcpy(manufacturer, compat, model ? model - compat : strlen(compat)); 85 86 pr_info("Board \"%s\" from %s (Manufacturer)\n", model, manufacturer); 87 88 /* Retrieve various information from the /chosen node */ 89 of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line); 90 91 /* Initialize {size,address}-cells info */ 92 of_scan_flat_dt(early_init_dt_scan_root, NULL); 93 94 /* Setup memory, calling early_init_dt_add_memory_arch */ 95 of_scan_flat_dt(early_init_dt_scan_memory, NULL); 96 97 clk = of_get_flat_dt_prop(dt_root, "clock-frequency", &len); 98 if (clk) 99 arc_set_core_freq(of_read_ulong(clk, len/4)); 100 101 return mdesc_best; 102 } 103 104 /* 105 * Copy the flattened DT out of .init since unflattening doesn't copy strings 106 * and the normal DT APIs refs them from orig flat DT 107 */ 108 void __init copy_devtree(void) 109 { 110 void *alloc = early_init_dt_alloc_memory_arch( 111 be32_to_cpu(initial_boot_params->totalsize), 64); 112 if (alloc) { 113 memcpy(alloc, initial_boot_params, 114 be32_to_cpu(initial_boot_params->totalsize)); 115 initial_boot_params = alloc; 116 } 117 } 118