[U-Boot] [PATCH] nios2: convert nios2 cpu to driver model

Thomas Chou thomas at wytron.com.tw
Thu Oct 1 04:31:31 CEST 2015


Convert nios2 cpu to driver model. The cpu parameters are
extracted from device tree and saved to global data structure.
We will use them to replace the custom_fpga.h .

Signed-off-by: Thomas Chou <thomas at wytron.com.tw>
---
v2
  move cpu param setup to arch_cpu_init_dm, remove probe.
v3
  fix coding style as Marek suggested.
  select CMD_CPU.
v4
  revert to v1 probe method.
  doc dts binding.
  check uclass_first_device() return.
  clean up as Simon suggested.

 arch/Kconfig                           |  3 ++
 arch/nios2/cpu/cpu.c                   | 88 ++++++++++++++++++++++++++++++++--
 arch/nios2/dts/3c120_devboard.dts      |  1 +
 arch/nios2/include/asm/global_data.h   |  8 ++++
 configs/nios2-generic_defconfig        |  3 +-
 doc/device-tree-bindings/cpu/nios2.txt | 54 +++++++++++++++++++++
 6 files changed, 152 insertions(+), 5 deletions(-)
 create mode 100644 doc/device-tree-bindings/cpu/nios2.txt

diff --git a/arch/Kconfig b/arch/Kconfig
index 207c778..9be1538 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -64,6 +64,9 @@ config NIOS2
 	select HAVE_GENERIC_BOARD
 	select SYS_GENERIC_BOARD
 	select SUPPORT_OF_CONTROL
+	select OF_CONTROL
+	select DM
+	select CPU
 
 config OPENRISC
 	bool "OpenRISC architecture"
diff --git a/arch/nios2/cpu/cpu.c b/arch/nios2/cpu/cpu.c
index 39ae972..bd11abc 100644
--- a/arch/nios2/cpu/cpu.c
+++ b/arch/nios2/cpu/cpu.c
@@ -6,7 +6,9 @@
  */
 
 #include <common.h>
-#include <asm/nios2.h>
+#include <cpu.h>
+#include <dm.h>
+#include <errno.h>
 #include <asm/cache.h>
 
 DECLARE_GLOBAL_DATA_PTR;
@@ -51,10 +53,90 @@ void dcache_disable(void)
 	flush_dcache(CONFIG_SYS_DCACHE_SIZE, CONFIG_SYS_DCACHELINE_SIZE);
 }
 
-int arch_cpu_init(void)
+int arch_cpu_init_dm(void)
 {
-	gd->cpu_clk = CONFIG_SYS_CLK_FREQ;
+	struct udevice *dev;
+	int ret;
+
+	ret = uclass_first_device(UCLASS_CPU, &dev);
+	if (ret)
+		return ret;
+	if (!dev)
+		return -ENODEV;
+
 	gd->ram_size = CONFIG_SYS_SDRAM_SIZE;
 
 	return 0;
 }
+
+static int altera_nios2_get_desc(struct udevice *dev, char *buf, int size)
+{
+	const char *cpu_name = "Nios-II";
+
+	if (size < strlen(cpu_name))
+		return -ENOSPC;
+	strcpy(buf, cpu_name);
+
+	return 0;
+}
+
+static int altera_nios2_get_info(struct udevice *dev, struct cpu_info *info)
+{
+	info->cpu_freq = gd->cpu_clk;
+	info->features = (1 << CPU_FEAT_L1_CACHE) |
+		(gd->arch.has_mmu ? (1 << CPU_FEAT_MMU) : 0);
+
+	return 0;
+}
+
+static int altera_nios2_get_count(struct udevice *dev)
+{
+	return 1;
+}
+
+static int altera_nios2_probe(struct udevice *dev)
+{
+	const void *blob = gd->fdt_blob;
+	int node = dev->of_offset;
+
+	gd->cpu_clk = fdtdec_get_int(blob, node,
+		"clock-frequency", 0);
+	gd->arch.dcache_line_size = fdtdec_get_int(blob, node,
+		"dcache-line-size", 0);
+	gd->arch.icache_line_size = fdtdec_get_int(blob, node,
+		"icache-line-size", 0);
+	gd->arch.dcache_size = fdtdec_get_int(blob, node,
+		"dcache-size", 0);
+	gd->arch.icache_size = fdtdec_get_int(blob, node,
+		"icache-size", 0);
+	gd->arch.reset_addr = fdtdec_get_int(blob, node,
+		"altr,reset-addr", 0);
+	gd->arch.exception_addr = fdtdec_get_int(blob, node,
+		"altr,exception-addr", 0);
+	gd->arch.has_mmu = fdtdec_get_int(blob, node,
+		"altr,has-mmu", 0);
+	gd->arch.io_region_base = gd->arch.has_mmu ? 0xe0000000 : 0x8000000;
+
+	return 0;
+}
+
+static const struct cpu_ops altera_nios2_ops = {
+	.get_desc	= altera_nios2_get_desc,
+	.get_info	= altera_nios2_get_info,
+	.get_count	= altera_nios2_get_count,
+};
+
+static const struct udevice_id altera_nios2_ids[] = {
+	{ .compatible = "altr,nios2-1.0" },
+	{ .compatible = "altr,nios2-1.1" },
+	{ }
+};
+
+U_BOOT_DRIVER(altera_nios2) = {
+	.name		= "altera_nios2",
+	.id		= UCLASS_CPU,
+	.of_match	= altera_nios2_ids,
+	.probe		= altera_nios2_probe,
+	.ops		= &altera_nios2_ops,
+	.flags		= DM_FLAG_PRE_RELOC,
+};
diff --git a/arch/nios2/dts/3c120_devboard.dts b/arch/nios2/dts/3c120_devboard.dts
index 781a652..2e2956f 100644
--- a/arch/nios2/dts/3c120_devboard.dts
+++ b/arch/nios2/dts/3c120_devboard.dts
@@ -41,6 +41,7 @@
 			altr,exception-addr = <0xd0000020>;
 			altr,has-initda = <1>;
 			altr,has-mmu = <1>;
+			u-boot,dm-pre-reloc;
 		};
 	};
 
diff --git a/arch/nios2/include/asm/global_data.h b/arch/nios2/include/asm/global_data.h
index 580b019..ee5180b 100644
--- a/arch/nios2/include/asm/global_data.h
+++ b/arch/nios2/include/asm/global_data.h
@@ -9,6 +9,14 @@
 
 /* Architecture-specific global data */
 struct arch_global_data {
+	u32 dcache_line_size;
+	u32 icache_line_size;
+	u32 dcache_size;
+	u32 icache_size;
+	u32 reset_addr;
+	u32 exception_addr;
+	int has_mmu;
+	u32 io_region_base;
 };
 
 #include <asm-generic/global_data.h>
diff --git a/configs/nios2-generic_defconfig b/configs/nios2-generic_defconfig
index ad72272..707ee33 100644
--- a/configs/nios2-generic_defconfig
+++ b/configs/nios2-generic_defconfig
@@ -4,6 +4,7 @@ CONFIG_DM_GPIO=y
 CONFIG_TARGET_NIOS2_GENERIC=y
 CONFIG_DEFAULT_DEVICE_TREE="3c120_devboard"
 CONFIG_HUSH_PARSER=y
+CONFIG_CMD_CPU=y
 # CONFIG_CMD_BOOTD is not set
 # CONFIG_CMD_IMLS is not set
 # CONFIG_CMD_XIMG is not set
@@ -13,9 +14,7 @@ CONFIG_HUSH_PARSER=y
 CONFIG_CMD_DHCP=y
 # CONFIG_CMD_NFS is not set
 CONFIG_CMD_PING=y
-CONFIG_OF_CONTROL=y
 CONFIG_NET_RANDOM_ETHADDR=y
-CONFIG_DM=y
 CONFIG_ALTERA_PIO=y
 CONFIG_ALTERA_JTAG_UART=y
 CONFIG_ALTERA_JTAG_UART_BYPASS=y
diff --git a/doc/device-tree-bindings/cpu/nios2.txt b/doc/device-tree-bindings/cpu/nios2.txt
new file mode 100644
index 0000000..0ed2f44
--- /dev/null
+++ b/doc/device-tree-bindings/cpu/nios2.txt
@@ -0,0 +1,54 @@
+* Nios II Processor Binding
+
+This binding specifies what properties available in the device tree
+representation of a Nios II Processor Core.
+
+Users can use sopc2dts tool for generating device tree sources (dts) from a
+Qsys system. See more detail in: http://www.alterawiki.com/wiki/Sopc2dts
+
+Required properties:
+
+- compatible: Compatible property value should be "altr,nios2-1.0" or
+  "altr,nios2-1.1".
+- reg: Contains CPU index.
+- clock-frequency: Contains the clock frequency for CPU, in Hz.
+- dcache-line-size: Contains data cache line size.
+- icache-line-size: Contains instruction line size.
+- dcache-size: Contains data cache size.
+- icache-size: Contains instruction cache size.
+- altr,reset-addr: Specifies CPU reset address
+- altr,exception-addr: Specifies CPU exception address
+
+Optional properties:
+- altr,has-initda: Specifies CPU support initda instruction, should be 1.
+- altr,has-mmu: Specifies CPU support MMU support.
+- altr,has-mul: Specifies CPU hardware multipy support.
+- altr,has-div: Specifies CPU hardware divide support
+- altr,implementation: Nios II core implementation, this should be "fast";
+
+Example:
+
+cpu at 0x0 {
+	device_type = "cpu";
+	compatible = "altr,nios2-1.0";
+	reg = <0>;
+	interrupt-controller;
+	#interrupt-cells = <1>;
+	clock-frequency = <125000000>;
+	dcache-line-size = <32>;
+	icache-line-size = <32>;
+	dcache-size = <32768>;
+	icache-size = <32768>;
+	altr,implementation = "fast";
+	altr,pid-num-bits = <8>;
+	altr,tlb-num-ways = <16>;
+	altr,tlb-num-entries = <128>;
+	altr,tlb-ptr-sz = <7>;
+	altr,has-div = <1>;
+	altr,has-mul = <1>;
+	altr,reset-addr = <0xc2800000>;
+	altr,fast-tlb-miss-addr = <0xc7fff400>;
+	altr,exception-addr = <0xd0000020>;
+	altr,has-initda = <1>;
+	altr,has-mmu = <1>;
+};
-- 
2.1.4



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