linux/arch/arc/kernel/devtree.c

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/*
* Copyright (C) 2012 Synopsys, Inc. (www.synopsys.com)
*
* Based on reduced version of METAG
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/init.h>
#include <linux/reboot.h>
#include <linux/memblock.h>
#include <linux/of.h>
#include <linux/of_fdt.h>
#include <asm/clk.h>
#include <asm/mach_desc.h>
#ifdef CONFIG_SERIAL_8250_CONSOLE
static unsigned int __initdata arc_base_baud;
unsigned int __init arc_early_base_baud(void)
{
return arc_base_baud/16;
}
static void __init arc_set_early_base_baud(unsigned long dt_root)
{
unsigned int core_clk = arc_get_core_freq();
if (of_flat_dt_is_compatible(dt_root, "abilis,arc-tb10x"))
arc_base_baud = core_clk/3;
else
arc_base_baud = core_clk;
}
#else
#define arc_set_early_base_baud(dt_root)
#endif
static const void * __init arch_get_next_mach(const char *const **match)
{
static const struct machine_desc *mdesc = __arch_info_begin;
const struct machine_desc *m = mdesc;
if (m >= __arch_info_end)
return NULL;
mdesc++;
*match = m->dt_compat;
return m;
}
/**
* setup_machine_fdt - Machine setup when an dtb was passed to the kernel
* @dt: virtual address pointer to dt blob
*
* If a dtb was passed to the kernel, then use it to choose the correct
* machine_desc and to setup the system.
*/
const struct machine_desc * __init setup_machine_fdt(void *dt)
{
const struct machine_desc *mdesc;
unsigned long dt_root;
const void *clk;
int len;
if (!early_init_dt_scan(dt))
return NULL;
mdesc = of_flat_dt_match_machine(NULL, arch_get_next_mach);
if (!mdesc)
machine_halt();
dt_root = of_get_flat_dt_root();
clk = of_get_flat_dt_prop(dt_root, "clock-frequency", &len);
if (clk)
arc_set_core_freq(of_read_ulong(clk, len/4));
arc_set_early_base_baud(dt_root);
return mdesc;
}