[2/3] riscv: K210: Add a built-in device tree

Commit Message

Damien Le Moal April 14, 2020, 4:43 a.m. UTC

From: Palmer Dabbelt <[e-mail]>

The K210's bootloader does not provide a device tree. Give the ability
to providea builtin one with the SOC_KENDRYTE_K210_BUILTIN_DTB option.
If selected, this option result in the definition of a builtin DTB
entry in the k210 sysctl driver.

If defined, the builtin DTB entry points to the default k210.dts device
tree file and is keyed with the vendor ID 0x4B5, the arch ID
0xE59889E6A5A04149 ("Canaan AI" in UTF-8 coded Chinese) and the impl ID
0x4D41495832303030 ("MAIX200"). These values are reported by the SiPEED
MAIXDUINO board, the SiPEED MAIX Go board and the SiPEED Dan Dock board.

Signed-off-by: Palmer Dabbelt <[e-mail]>
Signed-off-by: Damien Le Moal <[e-mail]>
---
 arch/riscv/Kconfig.socs               | 17 ++++++++++++++++-
 arch/riscv/boot/dts/Makefile          |  2 ++
 arch/riscv/boot/dts/kendryte/Makefile |  4 +++-
 drivers/soc/kendryte/k210-sysctl.c    | 12 ++++++++++++
 4 files changed, 33 insertions(+), 2 deletions(-)

Patch

diff --git a/arch/riscv/Kconfig.socs b/arch/riscv/Kconfig.socs
index 216286db81c9..4b2303ca20b9 100644
--- a/arch/riscv/Kconfig.socs
+++ b/arch/riscv/Kconfig.socs
@@ -23,11 +23,26 @@  config SOC_VIRT
 config SOC_KENDRYTE
 	bool "Kendryte K210 SoC"
 	depends on !MMU
-	select BUILTIN_DTB
 	select SERIAL_SIFIVE if TTY
 	select SERIAL_SIFIVE_CONSOLE if TTY
 	select SIFIVE_PLIC
 	help
 	  This enables support for Kendryte K210 SoC platform hardware.
 
+config SOC_KENDRYTE_K210_DTB
+	def_bool y
+	depends on SOC_KENDRYTE_K210_DTB_BUILTIN
+
+config SOC_KENDRYTE_K210_DTB_BUILTIN
+	bool "Builtin device tree for the Kendryte K210"
+	depends on SOC_KENDRYTE
+	default y
+	select OF
+	select BUILTIN_DTB
+	select SOC_KENDRYTE_K210_DTB
+	help
+	  Builds a device tree for the Kendryte K210 into the Linux image.
+	  This option should be selected if no bootloader is being used.
+	  If unsure, say Y.
+
 endmenu
diff --git a/arch/riscv/boot/dts/Makefile b/arch/riscv/boot/dts/Makefile
index 557f0b519c8e..ca1f8cbd78c0 100644
--- a/arch/riscv/boot/dts/Makefile
+++ b/arch/riscv/boot/dts/Makefile
@@ -1,3 +1,5 @@ 
 # SPDX-License-Identifier: GPL-2.0
 subdir-y += sifive
 subdir-y += kendryte
+
+obj-$(CONFIG_BUILTIN_DTB) := $(addsuffix /, $(subdir-y))
diff --git a/arch/riscv/boot/dts/kendryte/Makefile b/arch/riscv/boot/dts/kendryte/Makefile
index 815444e69e89..1a88e616f18e 100644
--- a/arch/riscv/boot/dts/kendryte/Makefile
+++ b/arch/riscv/boot/dts/kendryte/Makefile
@@ -1,2 +1,4 @@ 
 # SPDX-License-Identifier: GPL-2.0
-dtb-$(CONFIG_SOC_KENDRYTE) += k210.dtb
+dtb-$(CONFIG_SOC_KENDRYTE_K210_DTB) += k210.dtb
+
+obj-$(CONFIG_SOC_KENDRYTE_K210_DTB_BUILTIN) += $(addsuffix .o, $(dtb-y))
diff --git a/drivers/soc/kendryte/k210-sysctl.c b/drivers/soc/kendryte/k210-sysctl.c
index 4608fbca20e1..707019223dd8 100644
--- a/drivers/soc/kendryte/k210-sysctl.c
+++ b/drivers/soc/kendryte/k210-sysctl.c
@@ -246,3 +246,15 @@  static void __init k210_soc_early_init(const void *fdt)
 	iounmap(regs);
 }
 SOC_EARLY_INIT_DECLARE(generic_k210, "kendryte,k210", k210_soc_early_init);
+
+#ifdef CONFIG_SOC_KENDRYTE_K210_DTB_BUILTIN
+/*
+ * Generic entry for the default k210.dtb embedded DTB for boards with:
+ *   - Vendor ID: 0x4B5
+ *   - Arch ID: 0xE59889E6A5A04149 (= "Canaan AI" in UTF-8 encoded Chinese)
+ *   - Impl ID:	0x4D41495832303030 (= "MAIX2000")
+ * These values are reported by the SiPEED MAXDUINO, SiPEED MAIX GO and
+ * SiPEED Dan dock boards.
+ */
+SOC_BUILTIN_DTB_DECLARE(k210, 0x4B5, 0xE59889E6A5A04149, 0x4D41495832303030);
+#endif