diff options
author | Alexey Brodkin <abrodkin@synopsys.com> | 2017-08-15 21:13:55 +0300 |
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committer | Vineet Gupta <vgupta@synopsys.com> | 2017-09-01 11:26:28 -0700 |
commit | a518d63777a4e94e4b2dd86501604ec49ffe86b2 (patch) | |
tree | f98d850c9325aa584cc1b05c9820174a07268ccf /arch/arc/plat-hsdk/platform.c | |
parent | 9ed68785f7f2b001a6911d64fbd10cfc6fa49b27 (diff) | |
download | linux-a518d63777a4e94e4b2dd86501604ec49ffe86b2.tar.bz2 |
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>
Diffstat (limited to 'arch/arc/plat-hsdk/platform.c')
-rw-r--r-- | arch/arc/plat-hsdk/platform.c | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/arch/arc/plat-hsdk/platform.c b/arch/arc/plat-hsdk/platform.c new file mode 100644 index 000000000000..a2e7fd17e36d --- /dev/null +++ b/arch/arc/plat-hsdk/platform.c @@ -0,0 +1,66 @@ +/* + * ARC HSDK Platform support code + * + * Copyright (C) 2017 Synopsys, Inc. (www.synopsys.com) + * + * 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/smp.h> +#include <asm/arcregs.h> +#include <asm/io.h> +#include <asm/mach_desc.h> + +#define ARC_CCM_UNUSED_ADDR 0x60000000 + +static void __init hsdk_init_per_cpu(unsigned int cpu) +{ + /* + * By default ICCM is mapped to 0x7z while this area is used for + * kernel virtual mappings, so move it to currently unused area. + */ + if (cpuinfo_arc700[cpu].iccm.sz) + write_aux_reg(ARC_REG_AUX_ICCM, ARC_CCM_UNUSED_ADDR); + + /* + * By default DCCM is mapped to 0x8z while this area is used by kernel, + * so move it to currently unused area. + */ + if (cpuinfo_arc700[cpu].dccm.sz) + write_aux_reg(ARC_REG_AUX_DCCM, ARC_CCM_UNUSED_ADDR); +} + +#define ARC_PERIPHERAL_BASE 0xf0000000 +#define CREG_BASE (ARC_PERIPHERAL_BASE + 0x1000) +#define CREG_PAE (CREG_BASE + 0x180) +#define CREG_PAE_UPDATE (CREG_BASE + 0x194) + +static void __init hsdk_init_early(void) +{ + /* + * 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. + */ + + /* Default is 1, which means "PAE offset = 4GByte" */ + writel_relaxed(0, (void __iomem *) CREG_PAE); + + /* Really apply settings made above */ + writel(1, (void __iomem *) CREG_PAE_UPDATE); +} + +static const char *hsdk_compat[] __initconst = { + "snps,hsdk", + NULL, +}; + +MACHINE_START(SIMULATION, "hsdk") + .dt_compat = hsdk_compat, + .init_early = hsdk_init_early, + .init_per_cpu = hsdk_init_per_cpu, +MACHINE_END |