aboutsummaryrefslogtreecommitdiffstats
path: root/arch/arc/plat-hsdk/platform.c
diff options
context:
space:
mode:
authorAlexey Brodkin <abrodkin@synopsys.com>2017-08-15 21:13:55 +0300
committerVineet Gupta <vgupta@synopsys.com>2017-09-01 11:26:28 -0700
commita518d63777a4e94e4b2dd86501604ec49ffe86b2 (patch)
treef98d850c9325aa584cc1b05c9820174a07268ccf /arch/arc/plat-hsdk/platform.c
parentARC: mm: Decouple RAM base address from kernel link address (diff)
downloadlinux-dev-a518d63777a4e94e4b2dd86501604ec49ffe86b2.tar.xz
linux-dev-a518d63777a4e94e4b2dd86501604ec49ffe86b2.zip
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 '')
-rw-r--r--arch/arc/plat-hsdk/platform.c66
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