a518d63777
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>
67 lines
1.8 KiB
C
67 lines
1.8 KiB
C
/*
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* ARC HSDK Platform support code
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*
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* Copyright (C) 2017 Synopsys, Inc. (www.synopsys.com)
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/init.h>
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#include <linux/smp.h>
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#include <asm/arcregs.h>
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#include <asm/io.h>
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#include <asm/mach_desc.h>
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#define ARC_CCM_UNUSED_ADDR 0x60000000
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static void __init hsdk_init_per_cpu(unsigned int cpu)
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{
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/*
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* By default ICCM is mapped to 0x7z while this area is used for
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* kernel virtual mappings, so move it to currently unused area.
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*/
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if (cpuinfo_arc700[cpu].iccm.sz)
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write_aux_reg(ARC_REG_AUX_ICCM, ARC_CCM_UNUSED_ADDR);
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/*
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* By default DCCM is mapped to 0x8z while this area is used by kernel,
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* so move it to currently unused area.
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*/
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if (cpuinfo_arc700[cpu].dccm.sz)
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write_aux_reg(ARC_REG_AUX_DCCM, ARC_CCM_UNUSED_ADDR);
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}
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#define ARC_PERIPHERAL_BASE 0xf0000000
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#define CREG_BASE (ARC_PERIPHERAL_BASE + 0x1000)
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#define CREG_PAE (CREG_BASE + 0x180)
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#define CREG_PAE_UPDATE (CREG_BASE + 0x194)
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static void __init hsdk_init_early(void)
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{
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/*
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* PAE remapping for DMA clients does not work due to an RTL bug, so
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* CREG_PAE register must be programmed to all zeroes, otherwise it
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* will cause problems with DMA to/from peripherals even if PAE40 is
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* not used.
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*/
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/* Default is 1, which means "PAE offset = 4GByte" */
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writel_relaxed(0, (void __iomem *) CREG_PAE);
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/* Really apply settings made above */
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writel(1, (void __iomem *) CREG_PAE_UPDATE);
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}
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static const char *hsdk_compat[] __initconst = {
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"snps,hsdk",
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NULL,
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};
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MACHINE_START(SIMULATION, "hsdk")
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.dt_compat = hsdk_compat,
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.init_early = hsdk_init_early,
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.init_per_cpu = hsdk_init_per_cpu,
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MACHINE_END
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