[PATCH v9 21/21] riscv: Add Sipeed Maix support

Sean Anderson
2020-05-03T02:35:50Z

The Sipeed Maix series is a collection of boards built around the RISC-V
Kendryte K210 processor. This processor contains several peripherals to
accelerate neural network processing and other "ai" tasks. This includes a
"KPU" neural network processor, an audio processor supporting beamforming
reception, and a digital video port supporting capture and output at VGA
resolution. Other peripherals include 8M of sram (accessible with and
without caching); remappable pins, including 40 GPIOs; AES, FFT, and SHA256
accelerators; a DMA controller; and I2C, I2S, and SPI controllers. Maix
peripherals vary, but include spi flash; on-board usb-serial bridges; ports
for cameras, displays, and sd cards; and ESP32 chips. Currently, only the
Sipeed Maix Bit V2.0 (bitm) is supported, but the boards are fairly
similar.

Documentation for Maix boards is located at
<http://dl.sipeed.com/MAIX/HDK/>. Documentation for the Kendryte K210 is
located at <https://kendryte.com/downloads/>. However, hardware details are
rather lacking, so most technical reference has been taken from the
standalone sdk located at
<https://github.com/kendryte/kendryte-standalone-sdk>.

Signed-off-by: Sean Anderson <seanga2@gmail.com>
---

Changes in v9:
- Update MAINTAINERS to reflect defconfig name change

Changes in v8:
- Remove unnecessary fdt fixup for sipeed maix

Changes in v7:
- Split docs off into their own patch
- Enable ram clocks by name

Changes in v6:
- Remove trailing whitespace from documentation
- Remove configuration for spi/pinmux/gpio features
- Flesh out documentation some more

Changes in v5:
- Configure relocation location with CONFIG_SYS_SDRAM_*
- Enable ram clocks
- Add pinmux/gpio/led support
- Remove (broken) MMC support
- Store the environment in flash
- Add partitions
- Add bootcmd
- Add docs for pinctrl and booting

Changes in v4:
- Rework documentation to be organized by board mfg not cpu mfg
- Update docs to reflect working SPI support
- Add proper spi support
- Don't define unneecessary macros in config.h
- Lower the default stack so it isn't clobbered on relocation
- Update MAINTAINERS
- Update copyright

Changes in v3:
- Reorder to be last in the patch series
- Add documentation for the board
- Generate defconfig with "make savedefconfig"
- Update Kconfig to imply most features we need
- Update MAINTAINERS

Changes in v2:
- Select CONFIG_SYS_RISCV_NOCOUNTER
- Imply CONFIG_CLK_K210
- Remove spurious references to CONFIG_ARCH_K210
- Remove many configs from defconfig where the defaults were fine
- Add a few "not set" lines to suppress unneeded defaults
- Reduce pre-reloc malloc space, now that clocks initialization happens
later

arch/riscv/Kconfig | 4 +++
board/sipeed/maix/Kconfig | 47 ++++++++++++++++++++++++++++++
board/sipeed/maix/MAINTAINERS | 11 +++++++
board/sipeed/maix/Makefile | 5 ++++
board/sipeed/maix/maix.c | 41 ++++++++++++++++++++++++++
configs/sipeed_maix_bitm_defconfig | 8 +++++
include/configs/sipeed-maix.h | 24 +++++++++++++++
7 files changed, 140 insertions(+)
create mode 100644 board/sipeed/maix/Kconfig
create mode 100644 board/sipeed/maix/MAINTAINERS
create mode 100644 board/sipeed/maix/Makefile
create mode 100644 board/sipeed/maix/maix.c
create mode 100644 configs/sipeed_maix_bitm_defconfig
create mode 100644 include/configs/sipeed-maix.h

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index cb1ca31b1b..ba171b4918 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -20,6 +20,9 @@ config TARGET_QEMU_VIRT
config TARGET_SIFIVE_FU540
bool "Support SiFive FU540 Board"

+config TARGET_SIPEED_MAIX
+ bool "Support Sipeed Maix Board"
+
endchoice

config SYS_ICACHE_OFF
@@ -53,6 +56,7 @@ source "board/AndesTech/ax25-ae350/Kconfig"
source "board/emulation/qemu-riscv/Kconfig"
source "board/microchip/mpfs_icicle/Kconfig"
source "board/sifive/fu540/Kconfig"
+source "board/sipeed/maix/Kconfig"

# platform-specific options below
source "arch/riscv/cpu/ax25/Kconfig"
diff --git a/board/sipeed/maix/Kconfig b/board/sipeed/maix/Kconfig
new file mode 100644
index 0000000000..0cdcd32adc
--- /dev/null
+++ b/board/sipeed/maix/Kconfig
@@ -0,0 +1,47 @@
+# SPDX-License-Identifier: GPL-2.0+
+# Copyright (C) 2019-20 Sean Anderson <seanga2@gmail.com>
+
+if TARGET_SIPEED_MAIX
+
+config SYS_BOARD
+ default "maix"
+
+config SYS_VENDOR
+ default "sipeed"
+
+config SYS_CPU
+ default "generic"
+
+config SYS_CONFIG_NAME
+ default "sipeed-maix"
+
+config SYS_TEXT_BASE
+ default 0x80000000
+
+config DEFAULT_DEVICE_TREE
+ default "k210-maix-bit"
+
+config NR_CPUS
+ default 2
+
+config NR_DRAM_BANKS
+ default 3
+
+config BOARD_SPECIFIC_OPTIONS
+ def_bool y
+ select GENERIC_RISCV
+ select RISCV_PRIV_1_9
+ imply SMP
+ imply DM_SERIAL
+ imply SIFIVE_SERIAL
+ imply SIFIVE_CLINT
+ imply POWER_DOMAIN
+ imply SIMPLE_PM_BUS
+ imply CLK_CCF
+ imply CLK_COMPOSITE_CCF
+ imply CLK_K210
+ imply DM_RESET
+ imply RESET_SYSCON
+ imply SYSRESET
+ imply SYSRESET_SYSCON
+endif
diff --git a/board/sipeed/maix/MAINTAINERS b/board/sipeed/maix/MAINTAINERS
new file mode 100644
index 0000000000..e7bb9ec433
--- /dev/null
+++ b/board/sipeed/maix/MAINTAINERS
@@ -0,0 +1,11 @@
+Sipeed Maix BOARD
+M: Sean Anderson <seanga2@gmail.com>
+S: Maintained
+F: arch/riscv/dts/k210.dtsi
+F: arch/riscv/dts/k210-maix-bit.dts
+F: board/sipeed/maix/
+F: configs/sipeed_maix_bitm_defconfig
+F: doc/board/sipeed/
+F: include/configs/sipeed-maix.h
+F: include/dt-bindings/*/k210-sysctl.h
+F: test/dm/k210_pll.c
diff --git a/board/sipeed/maix/Makefile b/board/sipeed/maix/Makefile
new file mode 100644
index 0000000000..4acff5b31e
--- /dev/null
+++ b/board/sipeed/maix/Makefile
@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0+
+#
+# Copyright (c) 2019 Western Digital Corporation or its affiliates.
+
+obj-y += maix.o
diff --git a/board/sipeed/maix/maix.c b/board/sipeed/maix/maix.c
new file mode 100644
index 0000000000..cbcb23cf5c
--- /dev/null
+++ b/board/sipeed/maix/maix.c
@@ -0,0 +1,41 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2019-20 Sean Anderson <seanga2@gmail.com>
+ */
+
+#include <common.h>
+#include <clk.h>
+#include <dm.h>
+#include <fdt_support.h>
+#include <asm/io.h>
+
+phys_size_t get_effective_memsize(void)
+{
+ return CONFIG_SYS_SDRAM_SIZE;
+}
+
+int board_init(void)
+{
+ int ret, i;
+ const char * const banks[] = { "sram0", "sram1", "airam" };
+ ofnode memory;
+ struct clk clk;
+
+ /* Enable RAM clocks */
+ memory = ofnode_by_compatible(ofnode_null(), "kendryte,k210-sram");
+ if (ofnode_equal(memory, ofnode_null()))
+ return -ENOENT;
+
+ for (i = 0; i < ARRAY_SIZE(banks); i++) {
+ ret = clk_get_by_name_nodev(memory, banks[i], &clk);
+ if (ret)
+ continue;
+
+ ret = clk_enable(&clk);
+ clk_free(&clk);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
diff --git a/configs/sipeed_maix_bitm_defconfig b/configs/sipeed_maix_bitm_defconfig
new file mode 100644
index 0000000000..f48f7f06e9
--- /dev/null
+++ b/configs/sipeed_maix_bitm_defconfig
@@ -0,0 +1,8 @@
+CONFIG_RISCV=y
+CONFIG_TARGET_SIPEED_MAIX=y
+CONFIG_ARCH_RV64I=y
+CONFIG_SYS_REDUNDAND_ENVIRONMENT=y
+# CONFIG_NET is not set
+# CONFIG_INPUT is not set
+# CONFIG_DM_ETH is not set
+# CONFIG_EFI_LOADER is not set
diff --git a/include/configs/sipeed-maix.h b/include/configs/sipeed-maix.h
new file mode 100644
index 0000000000..a46473fc78
--- /dev/null
+++ b/include/configs/sipeed-maix.h
@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (C) 2019-20 Sean Anderson <seanga2@gmail.com>
+ */
+
+#ifndef CONFIGS_SIPEED_MAIX_H
+#define CONFIGS_SIPEED_MAIX_H
+
+#include <linux/sizes.h>
+
+#define CONFIG_SYS_LOAD_ADDR 0x80000000
+/* Start just below the second bank so we don't clobber it during reloc */
+#define CONFIG_SYS_INIT_SP_ADDR 0x803FFFFF
+#define CONFIG_SYS_MALLOC_LEN SZ_128K
+#define CONFIG_SYS_CACHELINE_SIZE 64
+
+#define CONFIG_SYS_SDRAM_BASE 0x80000000
+/* Don't relocate into AI ram since it isn't set up yet */
+#define CONFIG_SYS_SDRAM_SIZE (SZ_4M + SZ_2M)
+
+/* For early init */
+#define K210_SYSCTL_BASE 0x50440000
+
+#endif /* CONFIGS_SIPEED_MAIX_H */
--
2.26.2