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 machine_desc *mdesc = NULL, *mdesc_best = NULL; 31 unsigned int score, mdesc_score = ~1; 32 unsigned long dt_root; 33 const char *model, *compat; 34 void *clk; 35 char manufacturer[16]; 36 unsigned long len; 37 38 if (!early_init_dt_scan(dt)) 39 return NULL; 40 41 dt_root = of_get_flat_dt_root(); 42 43 /* 44 * The kernel could be multi-platform enabled, thus could have many 45 * "baked-in" machine descriptors. Search thru all for the best 46 * "compatible" string match. 47 */ 48 for_each_machine_desc(mdesc) { 49 score = of_flat_dt_match(dt_root, mdesc->dt_compat); 50 if (score > 0 && score < mdesc_score) { 51 mdesc_best = mdesc; 52 mdesc_score = score; 53 } 54 } 55 if (!mdesc_best) { 56 const char *prop; 57 long size; 58 59 pr_err("\n unrecognized device tree list:\n[ "); 60 61 prop = of_get_flat_dt_prop(dt_root, "compatible", &size); 62 if (prop) { 63 while (size > 0) { 64 printk("'%s' ", prop); 65 size -= strlen(prop) + 1; 66 prop += strlen(prop) + 1; 67 } 68 } 69 printk("]\n\n"); 70 71 machine_halt(); 72 } 73 74 /* compat = "<manufacturer>,<model>" */ 75 compat = mdesc_best->dt_compat[0]; 76 77 model = strchr(compat, ','); 78 if (model) 79 model++; 80 81 strlcpy(manufacturer, compat, model ? model - compat : strlen(compat)); 82 83 pr_info("Board \"%s\" from %s (Manufacturer)\n", model, manufacturer); 84 85 clk = of_get_flat_dt_prop(dt_root, "clock-frequency", &len); 86 if (clk) 87 arc_set_core_freq(of_read_ulong(clk, len/4)); 88 89 return mdesc_best; 90 } 91