linux_dsm_epyc7002/arch/arc/kernel/devtree.c
Alexey Brodkin a518d63777 ARC: [plat-hsdk] initial port for HSDK board
This initial port adds support of ARC HS Development Kit board with some
basic features such serial port, USB, SD/MMC and Ethernet.

Essentially we run Linux kernel on all 4 cores (i.e. utilize SMP) and
heavily use IO Coherency for speeding-up DMA-aware peripherals.

Note as opposed to other ARC boards we link Linux kernel to
0x9000_0000 intentionally because cores 1 and 3 configured with DCCM
situated at our more usual link base 0x8000_0000. We still can use
memory region starting at 0x8000_0000 as we reallocate DCCM in our
platform code.

Note that PAE remapping for DMA clients does not work due to an RTL bug,
so CREG_PAE register must be programmed to all zeroes, otherwise it will
cause problems with DMA to/from peripherals even if PAE40 is not used.

Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2017-09-01 11:26:28 -07:00

81 lines
2.0 KiB
C

/*
* 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/mach_desc.h>
#ifdef CONFIG_SERIAL_EARLYCON
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)
{
if (of_flat_dt_is_compatible(dt_root, "abilis,arc-tb10x"))
arc_base_baud = 166666666; /* Fixed 166.6MHz clk (TB10x) */
else if (of_flat_dt_is_compatible(dt_root, "snps,arc-sdp") ||
of_flat_dt_is_compatible(dt_root, "snps,hsdk"))
arc_base_baud = 33333333; /* Fixed 33MHz clk (AXS10x & HSDK) */
else if (of_flat_dt_is_compatible(dt_root, "ezchip,arc-nps"))
arc_base_baud = 800000000; /* Fixed 800MHz clk (NPS) */
else
arc_base_baud = 50000000; /* Fixed default 50MHz */
}
#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;
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();
arc_set_early_base_baud(dt_root);
return mdesc;
}