1 /* 2 * Procedures for creating, accessing and interpreting the device tree. 3 * 4 * Paul Mackerras August 1996. 5 * Copyright (C) 1996-2005 Paul Mackerras. 6 * 7 * Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner. 8 * {engebret|bergner}@us.ibm.com 9 * 10 * This program is free software; you can redistribute it and/or 11 * modify it under the terms of the GNU General Public License 12 * as published by the Free Software Foundation; either version 13 * 2 of the License, or (at your option) any later version. 14 */ 15 16 #include <stdarg.h> 17 #include <linux/export.h> 18 #include <linux/kernel.h> 19 #include <linux/string.h> 20 #include <linux/init.h> 21 #include <linux/threads.h> 22 #include <linux/spinlock.h> 23 #include <linux/types.h> 24 #include <linux/pci.h> 25 #include <linux/stringify.h> 26 #include <linux/delay.h> 27 #include <linux/initrd.h> 28 #include <linux/bitops.h> 29 #include <linux/kexec.h> 30 #include <linux/debugfs.h> 31 #include <linux/irq.h> 32 #include <linux/memblock.h> 33 #include <linux/of_fdt.h> 34 35 #include <asm/prom.h> 36 #include <asm/page.h> 37 #include <asm/processor.h> 38 #include <asm/irq.h> 39 #include <linux/io.h> 40 #include <asm/mmu.h> 41 #include <asm/pgtable.h> 42 #include <asm/sections.h> 43 #include <asm/pci-bridge.h> 44 45 #ifdef CONFIG_EARLY_PRINTK 46 static const char *stdout; 47 48 static int __init early_init_dt_scan_chosen_serial(unsigned long node, 49 const char *uname, int depth, void *data) 50 { 51 int l; 52 const char *p; 53 54 pr_debug("%s: depth: %d, uname: %s\n", __func__, depth, uname); 55 56 if (depth == 1 && (strcmp(uname, "chosen") == 0 || 57 strcmp(uname, "chosen@0") == 0)) { 58 p = of_get_flat_dt_prop(node, "linux,stdout-path", &l); 59 if (p != NULL && l > 0) 60 stdout = p; /* store pointer to stdout-path */ 61 } 62 63 if (stdout && strstr(stdout, uname)) { 64 p = of_get_flat_dt_prop(node, "compatible", &l); 65 pr_debug("Compatible string: %s\n", p); 66 67 if ((strncmp(p, "xlnx,xps-uart16550", 18) == 0) || 68 (strncmp(p, "xlnx,axi-uart16550", 18) == 0)) { 69 unsigned int addr; 70 71 *(u32 *)data = UART16550; 72 73 addr = *(u32 *)of_get_flat_dt_prop(node, "reg", &l); 74 addr += *(u32 *)of_get_flat_dt_prop(node, 75 "reg-offset", &l); 76 /* clear register offset */ 77 return be32_to_cpu(addr) & ~3; 78 } 79 if ((strncmp(p, "xlnx,xps-uartlite", 17) == 0) || 80 (strncmp(p, "xlnx,opb-uartlite", 17) == 0) || 81 (strncmp(p, "xlnx,axi-uartlite", 17) == 0) || 82 (strncmp(p, "xlnx,mdm", 8) == 0)) { 83 const unsigned int *addrp; 84 85 *(u32 *)data = UARTLITE; 86 87 addrp = of_get_flat_dt_prop(node, "reg", &l); 88 return be32_to_cpup(addrp); /* return address */ 89 } 90 } 91 return 0; 92 } 93 94 /* this function is looking for early console - Microblaze specific */ 95 int __init of_early_console(void *version) 96 { 97 return of_scan_flat_dt(early_init_dt_scan_chosen_serial, version); 98 } 99 #endif 100 101 void __init early_init_devtree(void *params) 102 { 103 pr_debug(" -> early_init_devtree(%p)\n", params); 104 105 early_init_dt_scan(params); 106 if (!strlen(boot_command_line)) 107 strlcpy(boot_command_line, cmd_line, COMMAND_LINE_SIZE); 108 109 parse_early_param(); 110 111 memblock_allow_resize(); 112 113 pr_debug("Phys. mem: %lx\n", (unsigned long) memblock_phys_mem_size()); 114 115 pr_debug(" <- early_init_devtree()\n"); 116 } 117