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/clk.h> 18 #include <asm/mach_desc.h> 19 20 #ifdef CONFIG_SERIAL_EARLYCON 21 22 static unsigned int __initdata arc_base_baud; 23 24 unsigned int __init arc_early_base_baud(void) 25 { 26 return arc_base_baud/16; 27 } 28 29 static void __init arc_set_early_base_baud(unsigned long dt_root) 30 { 31 unsigned int core_clk = arc_get_core_freq(); 32 33 if (of_flat_dt_is_compatible(dt_root, "abilis,arc-tb10x")) 34 arc_base_baud = core_clk/3; 35 else if (of_flat_dt_is_compatible(dt_root, "snps,arc-sdp")) 36 arc_base_baud = 33333333; /* Fixed 33MHz clk (AXS10x) */ 37 else 38 arc_base_baud = core_clk; 39 } 40 #else 41 #define arc_set_early_base_baud(dt_root) 42 #endif 43 44 static const void * __init arch_get_next_mach(const char *const **match) 45 { 46 static const struct machine_desc *mdesc = __arch_info_begin; 47 const struct machine_desc *m = mdesc; 48 49 if (m >= __arch_info_end) 50 return NULL; 51 52 mdesc++; 53 *match = m->dt_compat; 54 return m; 55 } 56 57 /** 58 * setup_machine_fdt - Machine setup when an dtb was passed to the kernel 59 * @dt: virtual address pointer to dt blob 60 * 61 * If a dtb was passed to the kernel, then use it to choose the correct 62 * machine_desc and to setup the system. 63 */ 64 const struct machine_desc * __init setup_machine_fdt(void *dt) 65 { 66 const struct machine_desc *mdesc; 67 unsigned long dt_root; 68 const void *clk; 69 int len; 70 71 if (!early_init_dt_scan(dt)) 72 return NULL; 73 74 mdesc = of_flat_dt_match_machine(NULL, arch_get_next_mach); 75 if (!mdesc) 76 machine_halt(); 77 78 dt_root = of_get_flat_dt_root(); 79 clk = of_get_flat_dt_prop(dt_root, "clock-frequency", &len); 80 if (clk) 81 arc_set_core_freq(of_read_ulong(clk, len/4)); 82 83 arc_set_early_base_baud(dt_root); 84 85 return mdesc; 86 } 87