Message-ID: <20161213185616.GA25417@nathan3500-linux-VM>
Date:   Tue, 13 Dec 2016 12:56:16 -0600
From:   Nathan Sullivan <nathan.sullivan@...com>
To:     Paul Burton <paul.burton@...tec.com>
CC:     <linux-mips@...ux-mips.org>, <ralf@...ux-mips.org>,
        <mark.rutland@....com>, <robh+dt@...nel.org>,
        <devicetree@...r.kernel.org>, <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] MIPS: NI 169445 board support

On Tue, Dec 13, 2016 at 06:40:31PM +0000, Paul Burton wrote:
> Hi Nathan,
> 
> On Friday, 2 December 2016 09:42:09 GMT Nathan Sullivan wrote:
> > Support the National Instruments 169445 board.
> > 
> > Signed-off-by: Nathan Sullivan <nathan.sullivan@...com>
> > ---
> > "gpio: mmio: add support for NI 169445 NAND GPIO" and
> > "devicetree: add vendor prefix for National Instruments" are required for
> > the NAND on this board to work.
> > 
> >  Documentation/devicetree/bindings/mips/ni.txt |   7 ++
> >  arch/mips/Kbuild.platforms                    |   1 +
> >  arch/mips/Kconfig                             |  26 ++++++
> >  arch/mips/boot/dts/Makefile                   |   1 +
> >  arch/mips/boot/dts/ni/169445.dts              |  99 +++++++++++++++++++++
> >  arch/mips/boot/dts/ni/Makefile                |   9 ++
> >  arch/mips/configs/ni169445_defconfig          | 120 ++++++++++++++++++++++++++
> >  arch/mips/ni169445/169445-console.c           |  38 ++++++++
> >  arch/mips/ni169445/169445-init.c              |  39 +++++++++
> >  arch/mips/ni169445/169445-int.c               |  34 ++++++++
> >  arch/mips/ni169445/169445-setup.c             |  58 +++++++++++++
> >  arch/mips/ni169445/169445-time.c              |  35 ++++++++
> >  arch/mips/ni169445/Makefile                   |   9 ++
> >  arch/mips/ni169445/Platform                   |   6 ++
> >  14 files changed, 482 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/mips/ni.txt
> >  create mode 100644 arch/mips/boot/dts/ni/169445.dts
> >  create mode 100644 arch/mips/boot/dts/ni/Makefile
> >  create mode 100644 arch/mips/configs/ni169445_defconfig
> >  create mode 100644 arch/mips/ni169445/169445-console.c
> >  create mode 100644 arch/mips/ni169445/169445-init.c
> >  create mode 100644 arch/mips/ni169445/169445-int.c
> >  create mode 100644 arch/mips/ni169445/169445-setup.c
> >  create mode 100644 arch/mips/ni169445/169445-time.c
> >  create mode 100644 arch/mips/ni169445/Makefile
> >  create mode 100644 arch/mips/ni169445/Platform
> > 
> > diff --git a/Documentation/devicetree/bindings/mips/ni.txt
> > b/Documentation/devicetree/bindings/mips/ni.txt new file mode 100644
> > index 0000000..722bf2d
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/mips/ni.txt
> > @@ -0,0 +1,7 @@
> > +National Instruments MIPS platforms
> > +
> > +required root node properties:
> > +	- compatible: must be "ni,169445"
> > +
> > +CPU Nodes
> > +	- compatible: must be "mti,mips14KEc"
> 
> This doesn't describe anything else you rely on, like the
> mips-hpt-frequency property which you panic without.
> 
> > diff --git a/arch/mips/Kbuild.platforms b/arch/mips/Kbuild.platforms
> > index f5f1bdb..f2d7b5c 100644
> > --- a/arch/mips/Kbuild.platforms
> > +++ b/arch/mips/Kbuild.platforms
> > @@ -20,6 +20,7 @@ platforms += loongson32
> >  platforms += loongson64
> >  platforms += mti-malta
> >  platforms += netlogic
> > +platforms += ni169445
> >  platforms += paravirt
> >  platforms += pic32
> >  platforms += pistachio
> > diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
> > index b3c5bde..d24d11f 100644
> > --- a/arch/mips/Kconfig
> > +++ b/arch/mips/Kconfig
> > @@ -574,6 +574,32 @@ config NXP_STB225
> >  	help
> >  	 Support for NXP Semiconductors STB225 Development Board.
> > 
> > +config NI_169445
> > +	bool "NI 169445 board"
> > +	select ARCH_WANT_OPTIONAL_GPIOLIB
> > +	select BOOT_ELF32
> > +	select BOOT_RAW
> > +	select BUILTIN_DTB
> > +	select CEVT_R4K
> > +	select CSRC_R4K
> > +	select CPU_MIPSR2_IRQ_VI
> > +	select CPU_MIPSR2_IRQ_EI
> > +	select DMA_NONCOHERENT
> > +	select IRQ_MIPS_CPU
> > +	select LIBFDT
> > +	select MIPS_MSC
> > +	select SYS_HAS_CPU_MIPS32_R1
> > +	select SYS_HAS_CPU_MIPS32_R2
> > +	select SYS_HAS_EARLY_PRINTK
> > +	select SYS_SUPPORTS_32BIT_KERNEL
> > +	select SYS_SUPPORTS_LITTLE_ENDIAN
> > +	select USE_OF
> > +	select COMMON_CLK
> > +	help
> > +	  This enables support for the National Instruments 169445A
> > +	  board.
> > +
> > +
> >  config PMC_MSP
> >  	bool "PMC-Sierra MSP chipsets"
> >  	select CEVT_R4K
> > diff --git a/arch/mips/boot/dts/Makefile b/arch/mips/boot/dts/Makefile
> > index fc7a0a9..65a0ad8 100644
> > --- a/arch/mips/boot/dts/Makefile
> > +++ b/arch/mips/boot/dts/Makefile
> > @@ -3,6 +3,7 @@ dts-dirs	+= cavium-octeon
> >  dts-dirs	+= ingenic
> >  dts-dirs	+= lantiq
> >  dts-dirs	+= mti
> > +dts-dirs	+= ni
> >  dts-dirs	+= netlogic
> >  dts-dirs	+= pic32
> >  dts-dirs	+= qca
> > diff --git a/arch/mips/boot/dts/ni/169445.dts
> > b/arch/mips/boot/dts/ni/169445.dts new file mode 100644
> > index 0000000..a2b49f9
> > --- /dev/null
> > +++ b/arch/mips/boot/dts/ni/169445.dts
> > @@ -0,0 +1,99 @@
> > +/dts-v1/;
> > +
> > +/ {
> > +	#address-cells = <1>;
> > +	#size-cells = <1>;
> > +	compatible = "ni,169445";
> > +
> > +	cpus {
> > +		mips-hpt-frequency = <25000000>;
> > +
> > +		cpu@0 {
> > +			compatible = "mti,mips14KEc";
> > +		};
> > +	};
> > +
> > +	memory {
> > +		device_type = "memory";
> > +		reg = <0x0 0x08000000>;
> > +	};
> > +
> > +	clocks {
> > +		baseclk: baseclock {
> > +			compatible = "fixed-clock";
> > +			#clock-cells = <0>;
> > +			clock-frequency = <50000000>;
> > +		};
> > +	};
> > +
> > +	cpu_intc: cpu_intc {
> > +		#address-cells = <0>;
> > +		compatible = "mti,cpu-interrupt-controller";
> > +		interrupt-controller;
> > +		#interrupt-cells = <1>;
> > +	};
> > +
> > +	ahb@0 {
> > +		compatible = "simple-bus";
> > +		#address-cells = <1>;
> > +		#size-cells = <1>;
> > +		ranges;
> > +
> > +		gpio1: nand-gpio-out@...00010 {
> > +			compatible = "ni,169445-nand-gpio";
> > +			reg = <0x1f300010 0x4>;
> > +			reg-names = "dat";
> > +			gpio-controller;
> > +			#gpio-cells = <2>;
> > +			ngpios = <5>;
> > +		};
> > +
> > +		gpio2: nand-gpio-in@...00014 {
> > +			compatible = "ni,169445-nand-gpio";
> > +			reg = <0x1f300014 0x4>;
> > +			reg-names = "dat";
> > +			gpio-controller;
> > +			#gpio-cells = <2>;
> > +			ngpios = <1>;
> > +		};
> > +
> > +		nand@...00000 {
> > +			compatible = "gpio-control-nand";
> > +			nand-on-flash-bbt;
> > +			nand-ecc-mode = "soft_bch";
> > +			nand-ecc-step-size = <512>;
> > +			nand-ecc-strength = <4>;
> > +			reg = <0x1f300000 4>;
> > +			gpios = <&gpio2 0 0>, /* rdy */
> > +				<&gpio1 1 0>, /* nce */
> > +				<&gpio1 2 0>, /* ale */
> > +				<&gpio1 3 0>, /* cle */
> > +				<&gpio1 4 0>; /* nwp */
> > +		};
> > +
> > +		serial@...80000 {
> > +			compatible = "ns16550a";
> > +			reg = <0x1f380000 0x1000>;
> > +			interrupt-parent = <&cpu_intc>;
> > +			interrupts = <6>;
> > +			clocks = <&baseclk>;
> > +			reg-shift = <0>;
> > +		};
> > +
> > +		ethernet@...40000 {
> > +			compatible = "snps,dwc-qos-ethernet-4.10";
> > +			interrupt-parent = <&cpu_intc>;
> > +			interrupts = <5>;
> > +			reg = <0x1f340000 0x2000>;
> > +			clock-names = "apb_pclk", "phy_ref_clk";
> > +			clocks = <&baseclk>, <&baseclk>;
> > +
> > +			phy-mode = "rgmii";
> > +
> > +			fixed-link {
> > +				speed = <1000>;
> > +				full-duplex;
> > +			};
> > +		};
> > +	};
> > +};
> > diff --git a/arch/mips/boot/dts/ni/Makefile b/arch/mips/boot/dts/ni/Makefile
> > new file mode 100644
> > index 0000000..5291c18
> > --- /dev/null
> > +++ b/arch/mips/boot/dts/ni/Makefile
> > @@ -0,0 +1,9 @@
> > +dtb-$(CONFIG_NI_169445)		+= 169445.dtb
> > +
> > +obj-y				+= $(patsubst %.dtb, %.dtb.o, $(dtb-y))
> > +
> > +# Force kbuild to make empty built-in.o if necessary
> > +obj-				+= dummy.o
> > +
> > +always				:= $(dtb-y)
> > +clean-files			:= *.dtb *.dtb.S
> > diff --git a/arch/mips/configs/ni169445_defconfig
> > b/arch/mips/configs/ni169445_defconfig new file mode 100644
> > index 0000000..e5a34df
> > --- /dev/null
> > +++ b/arch/mips/configs/ni169445_defconfig
> > @@ -0,0 +1,120 @@
> > +CONFIG_NI_169445=y
> > +CONFIG_CPU_MIPS32_R2=y
> > +CONFIG_HZ_100=y
> > +CONFIG_MIPS_CMDLINE_FROM_BOOTLOADER=y
> > +# CONFIG_SWAP is not set
> > +CONFIG_SYSVIPC=y
> > +CONFIG_HZ_PERIODIC=y
> > +CONFIG_NO_HZ=y
> > +CONFIG_HIGH_RES_TIMERS=y
> > +CONFIG_IKCONFIG=y
> > +CONFIG_IKCONFIG_PROC=y
> > +CONFIG_LOG_BUF_SHIFT=15
> > +CONFIG_BLK_DEV_INITRD=y
> > +# CONFIG_RD_GZIP is not set
> > +# CONFIG_RD_LZMA is not set
> > +# CONFIG_RD_XZ is not set
> > +# CONFIG_RD_LZO is not set
> > +# CONFIG_RD_LZ4 is not set
> > +# CONFIG_SHMEM is not set
> > +CONFIG_EMBEDDED=y
> > +CONFIG_SLAB=y
> > +CONFIG_PROFILING=y
> > +# CONFIG_LBDAF is not set
> > +# CONFIG_BLK_DEV_BSG is not set
> > +# CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS is not set
> > +# CONFIG_SUSPEND is not set
> > +CONFIG_NET=y
> > +CONFIG_PACKET=y
> > +CONFIG_UNIX=y
> > +CONFIG_INET=y
> > +# CONFIG_INET_XFRM_MODE_TRANSPORT is not set
> > +# CONFIG_INET_XFRM_MODE_TUNNEL is not set
> > +# CONFIG_INET_XFRM_MODE_BEET is not set
> > +# CONFIG_INET_DIAG is not set
> > +# CONFIG_INET6_XFRM_MODE_TRANSPORT is not set
> > +# CONFIG_INET6_XFRM_MODE_TUNNEL is not set
> > +CONFIG_NETFILTER=y
> > +CONFIG_NETFILTER_XT_MATCH_MULTIPORT=y
> > +CONFIG_IP_NF_IPTABLES=y
> > +CONFIG_IP_NF_FILTER=y
> > +CONFIG_IP6_NF_IPTABLES=y
> > +CONFIG_IP6_NF_FILTER=y
> > +# CONFIG_WIRELESS is not set
> > +CONFIG_UEVENT_HELPER_PATH="/sbin/hotplug"
> > +CONFIG_DEVTMPFS=y
> > +CONFIG_DEVTMPFS_MOUNT=y
> > +CONFIG_MTD=y
> > +CONFIG_MTD_CMDLINE_PARTS=y
> > +CONFIG_MTD_BLOCK_RO=y
> > +CONFIG_MTD_NAND=y
> > +CONFIG_MTD_NAND_ECC_BCH=y
> > +CONFIG_MTD_NAND_GPIO=y
> > +CONFIG_MTD_UBI=y
> > +CONFIG_MTD_UBI_BLOCK=y
> > +CONFIG_NETDEVICES=y
> > +# CONFIG_NET_VENDOR_AMAZON is not set
> > +# CONFIG_NET_VENDOR_ARC is not set
> > +# CONFIG_NET_CADENCE is not set
> > +# CONFIG_NET_VENDOR_BROADCOM is not set
> > +# CONFIG_NET_VENDOR_EZCHIP is not set
> > +# CONFIG_NET_VENDOR_INTEL is not set
> > +# CONFIG_NET_VENDOR_MARVELL is not set
> > +# CONFIG_NET_VENDOR_MICREL is not set
> > +# CONFIG_NET_VENDOR_NATSEMI is not set
> > +# CONFIG_NET_VENDOR_NETRONOME is not set
> > +# CONFIG_NET_VENDOR_QUALCOMM is not set
> > +# CONFIG_NET_VENDOR_RENESAS is not set
> > +# CONFIG_NET_VENDOR_ROCKER is not set
> > +# CONFIG_NET_VENDOR_SAMSUNG is not set
> > +# CONFIG_NET_VENDOR_SEEQ is not set
> > +# CONFIG_NET_VENDOR_SMSC is not set
> > +# CONFIG_NET_VENDOR_STMICRO is not set
> > +CONFIG_SYNOPSYS_DWC_ETH_QOS=y
> > +# CONFIG_NET_VENDOR_VIA is not set
> > +# CONFIG_NET_VENDOR_WIZNET is not set
> > +# CONFIG_NET_VENDOR_XILINX is not set
> > +# CONFIG_WLAN is not set
> > +# CONFIG_INPUT_MOUSEDEV is not set
> > +# CONFIG_INPUT_KEYBOARD is not set
> > +# CONFIG_INPUT_MOUSE is not set
> > +# CONFIG_SERIO is not set
> > +# CONFIG_CONSOLE_TRANSLATIONS is not set
> > +CONFIG_VT_HW_CONSOLE_BINDING=y
> > +CONFIG_LEGACY_PTY_COUNT=32
> > +CONFIG_SERIAL_8250=y
> > +# CONFIG_SERIAL_8250_DEPRECATED_OPTIONS is not set
> > +CONFIG_SERIAL_8250_CONSOLE=y
> > +CONFIG_SERIAL_8250_NR_UARTS=2
> > +CONFIG_SERIAL_8250_RUNTIME_UARTS=2
> > +CONFIG_SERIAL_OF_PLATFORM=y
> > +# CONFIG_HW_RANDOM is not set
> > +CONFIG_GPIOLIB=y
> > +CONFIG_GPIO_SYSFS=y
> > +CONFIG_GPIO_GENERIC_PLATFORM=y
> > +# CONFIG_HWMON is not set
> > +# CONFIG_VGA_CONSOLE is not set
> > +# CONFIG_HID is not set
> > +# CONFIG_USB_SUPPORT is not set
> > +# CONFIG_MIPS_PLATFORM_DEVICES is not set
> > +# CONFIG_IOMMU_SUPPORT is not set
> > +CONFIG_UBIFS_FS=y
> > +CONFIG_UBIFS_FS_ADVANCED_COMPR=y
> > +# CONFIG_UBIFS_FS_ZLIB is not set
> > +CONFIG_SQUASHFS=y
> > +# CONFIG_SQUASHFS_ZLIB is not set
> > +CONFIG_SQUASHFS_LZO=y
> > +CONFIG_SQUASHFS_XZ=y
> > +# CONFIG_NETWORK_FILESYSTEMS is not set
> > +# CONFIG_FTRACE is not set
> > +CONFIG_CRYPTO_CBC=y
> > +CONFIG_CRYPTO_ECB=y
> > +CONFIG_CRYPTO_CRC32C=y
> > +CONFIG_CRYPTO_ARC4=y
> > +# CONFIG_CRYPTO_HW is not set
> > +# CONFIG_XZ_DEC_X86 is not set
> > +# CONFIG_XZ_DEC_POWERPC is not set
> > +# CONFIG_XZ_DEC_IA64 is not set
> > +# CONFIG_XZ_DEC_ARM is not set
> > +# CONFIG_XZ_DEC_ARMTHUMB is not set
> > +# CONFIG_XZ_DEC_SPARC is not set
> > diff --git a/arch/mips/ni169445/169445-console.c
> > b/arch/mips/ni169445/169445-console.c new file mode 100644
> > index 0000000..f07e48b
> > --- /dev/null
> > +++ b/arch/mips/ni169445/169445-console.c
> > @@ -0,0 +1,38 @@
> > +/*  Copyright 2016 National Instruments Corporation
> > + *
> > + *  This program is free software; you can redistribute it and/or modify it
> > + *  under the terms of the GNU General Public License as published by the
> > Free + *  Software Foundation; either version 2 of the License, or (at your
> > option) + *  any later version.
> > + *
> > + *  This program is distributed in the hope that it will be useful, but
> > WITHOUT + *  ANY WARRANTY; without even the implied warranty of
> > MERCHANTABILITY or + *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> > General Public License for + *  more details.
> > + */
> > +#include <linux/init.h>
> > +#include <linux/console.h>
> > +#include <linux/serial_reg.h>
> > +#include <linux/io.h>
> > +
> > +#define NI_UART0_REGS_BASE	((unsigned char __iomem *)0xbf380000)
> > +
> > +static inline unsigned char serial_in(int offset)
> > +{
> > +	return __raw_readb(NI_UART0_REGS_BASE + offset);
> > +}
> > +
> > +static inline void serial_out(int offset, char value)
> > +{
> > +	__raw_writeb(value, NI_UART0_REGS_BASE + offset);
> > +}
> > +
> > +int prom_putchar(char c)
> > +{
> > +	while ((serial_in(UART_LSR) & UART_LSR_THRE) == 0)
> > +		;
> > +
> > +	serial_out(UART_TX, c);
> > +
> > +	return 1;
> > +}
> 
> Could you use the generic 16550 earlycon support? (see CONFIG_SERIAL_8250_CONSOLE)
> 
> > diff --git a/arch/mips/ni169445/169445-init.c
> > b/arch/mips/ni169445/169445-init.c new file mode 100644
> > index 0000000..5c7ff5e
> > --- /dev/null
> > +++ b/arch/mips/ni169445/169445-init.c
> > @@ -0,0 +1,39 @@
> > +/*  Copyright 2016 National Instruments Corporation
> > + *
> > + *  This program is free software; you can redistribute it and/or modify it
> > + *  under the terms of the GNU General Public License as published by the
> > Free + *  Software Foundation; either version 2 of the License, or (at your
> > option) + *  any later version.
> > + *
> > + *  This program is distributed in the hope that it will be useful, but
> > WITHOUT + *  ANY WARRANTY; without even the implied warranty of
> > MERCHANTABILITY or + *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> > General Public License for + *  more details.
> > + */
> > +#include <linux/init.h>
> > +#include <linux/initrd.h>
> > +#include <linux/io.h>
> > +
> > +#include <asm/bootinfo.h>
> > +#include <asm/cacheflush.h>
> > +#include <asm/traps.h>
> > +#include <asm/mips-boards/generic.h>
> > +#include <asm/fw/fw.h>
> > +
> > +void __init prom_init(void)
> > +{
> > +	fw_init_cmdline();
> > +
> > +#ifdef CONFIG_BLK_DEV_INITRD
> > +	/* Read the initrd address from the firmware environment */
> > +	initrd_start = fw_getenvl("initrd_start");
> > +	if (initrd_start) {
> > +		initrd_start = KSEG0ADDR(initrd_start);
> > +		initrd_end = initrd_start + fw_getenvl("initrd_size");
> > +	}
> > +#endif
> > +}
> > +
> > +void __init prom_free_prom_memory(void)
> > +{
> > +}
> > diff --git a/arch/mips/ni169445/169445-int.c
> > b/arch/mips/ni169445/169445-int.c new file mode 100644
> > index 0000000..83caf79
> > --- /dev/null
> > +++ b/arch/mips/ni169445/169445-int.c
> > @@ -0,0 +1,34 @@
> > +/*  Copyright 2016 National Instruments Corporation
> > + *
> > + *  This program is free software; you can redistribute it and/or modify it
> > + *  under the terms of the GNU General Public License as published by the
> > Free + *  Software Foundation; either version 2 of the License, or (at your
> > option) + *  any later version.
> > + *
> > + *  This program is distributed in the hope that it will be useful, but
> > WITHOUT + *  ANY WARRANTY; without even the implied warranty of
> > MERCHANTABILITY or + *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> > General Public License for + *  more details.
> > + */
> > +#include <linux/init.h>
> > +#include <linux/irq.h>
> > +#include <linux/of_irq.h>
> > +#include <linux/irqchip/mips-gic.h>
> > +#include <linux/io.h>
> > +
> > +#include <asm/irq_cpu.h>
> > +#include <asm/setup.h>
> > +
> > +static const struct of_device_id of_irq_ids[] __initconst = {
> > +	{
> > +		.compatible = "mti,cpu-interrupt-controller",
> > +		.data = mips_cpu_irq_of_init
> > +	},
> > +	{},
> > +};
> > +
> > +void __init arch_init_irq(void)
> > +{
> > +	of_irq_init(of_irq_ids);
> > +}
> 
> The CPU interrupt controller driver already does an IRQCHIP_DECLARE to
> provide its compatible string, so can you just use irqchip_init()?
> 
> > +
> > diff --git a/arch/mips/ni169445/169445-setup.c
> > b/arch/mips/ni169445/169445-setup.c new file mode 100644
> > index 0000000..80a5c91
> > --- /dev/null
> > +++ b/arch/mips/ni169445/169445-setup.c
> > @@ -0,0 +1,58 @@
> > +/*  Copyright 2016 National Instruments Corporation
> > + *
> > + *  This program is free software; you can redistribute it and/or modify it
> > + *  under the terms of the GNU General Public License as published by the
> > Free + *  Software Foundation; either version 2 of the License, or (at your
> > option) + *  any later version.
> > + *
> > + *  This program is distributed in the hope that it will be useful, but
> > WITHOUT + *  ANY WARRANTY; without even the implied warranty of
> > MERCHANTABILITY or + *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> > General Public License for + *  more details.
> > + */
> > +#include <linux/init.h>
> > +#include <linux/clk-provider.h>
> > +#include <linux/libfdt.h>
> > +#include <linux/of_platform.h>
> > +#include <linux/of_fdt.h>
> > +
> > +#include <asm/prom.h>
> > +#include <asm/fw/fw.h>
> > +
> > +#include <asm/mips-boards/generic.h>
> > +
> > +const char *get_system_type(void)
> > +{
> > +	return "NI 169445 FPGA";
> > +}
> > +
> > +void __init plat_mem_setup(void)
> > +{
> > +	/*
> > +	 * Load the builtin devicetree. This causes the chosen node to be
> > +	 * parsed resulting in our memory appearing
> > +	 */
> > +	__dt_setup_arch(__dtb_start);
> > +}
> > +
> > +void __init device_tree_init(void)
> > +{
> > +	if (!initial_boot_params)
> > +		return;
> > +
> > +	unflatten_and_copy_device_tree();
> > +}
> > +
> > +static int __init customize_machine(void)
> > +{
> > +	of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
> > +	return 0;
> > +}
> > +arch_initcall(customize_machine);
> > +
> > +static int __init plat_dev_init(void)
> > +{
> > +	of_clk_init(NULL);
> > +	return 0;
> > +}
> > +device_initcall(plat_dev_init);
> > diff --git a/arch/mips/ni169445/169445-time.c
> > b/arch/mips/ni169445/169445-time.c new file mode 100644
> > index 0000000..3d2499e
> > --- /dev/null
> > +++ b/arch/mips/ni169445/169445-time.c
> > @@ -0,0 +1,35 @@
> > +/*  Copyright 2016 National Instruments Corporation
> > + *
> > + *  This program is free software; you can redistribute it and/or modify it
> > + *  under the terms of the GNU General Public License as published by the
> > Free + *  Software Foundation; either version 2 of the License, or (at your
> > option) + *  any later version.
> > + *
> > + *  This program is distributed in the hope that it will be useful, but
> > WITHOUT + *  ANY WARRANTY; without even the implied warranty of
> > MERCHANTABILITY or + *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> > General Public License for + *  more details.
> > + */
> > +
> > +#include <linux/init.h>
> > +#include <linux/of.h>
> > +
> > +#include <asm/time.h>
> > +
> > +void __init plat_time_init(void)
> > +{
> > +	struct device_node *np;
> > +	u32 freq;
> > +
> > +	np = of_find_node_by_name(NULL, "cpus");
> > +	if (!np)
> > +		panic("missing 'cpus' DT node");
> > +	if (of_property_read_u32(np, "mips-hpt-frequency", &freq) < 0)
> > +		panic("missing 'mips-hpt-frequency' property");
> 
> I think "clock-frequency" would be more standard, and the kernel would
> then just halve it to find the frequency at which the cop0 count register
> increments.
> 
> > +	of_node_put(np);
> > +
> > +	mips_hpt_frequency = freq;
> > +
> > +	/* IRQs will not work until the timer has been set at least once */
> > +	write_c0_count(0);
> 
> Really? Do you have any details of this, it sounds weird. Do you mean
> only the cop0 compare interrupt won't work until count is set? If so (and
> that sounds strange in itself) perhaps r4k_clockevent_init() ought to do
> this rather than some platform/board code.
> 

Yes, the cop0 interrupt doesn't fire until you write count once.  U-boot does
this in its MIPS timer code, and our hardware team confirmed this is the case.
I added this line before we started booting with U-boot, so it is probably fine
without it now.

> > +}
> > diff --git a/arch/mips/ni169445/Makefile b/arch/mips/ni169445/Makefile
> > new file mode 100644
> > index 0000000..f3a0c8c
> > --- /dev/null
> > +++ b/arch/mips/ni169445/Makefile
> > @@ -0,0 +1,9 @@
> > +#
> > +#
> > +obj-y				:= 169445-init.o \
> > +				   169445-int.o 169445-setup.o \
> > +				   169445-time.o
> > +
> > +obj-$(CONFIG_EARLY_PRINTK)	+= 169445-console.o
> > +
> > +CFLAGS_169445-setup.o = -I$(src)/../../../scripts/dtc/libfdt
> > diff --git a/arch/mips/ni169445/Platform b/arch/mips/ni169445/Platform
> > new file mode 100644
> > index 0000000..9380312
> > --- /dev/null
> > +++ b/arch/mips/ni169445/Platform
> > @@ -0,0 +1,6 @@
> > +#
> > +# National Instruments 169445 FPGA board
> > +#
> > +platform-$(CONFIG_NI_169445)	+= ni169445/
> > +load-$(CONFIG_NI_169445)	+= 0xffffffff80002000
> > +all-$(CONFIG_NI_169445)		:= $(COMPRESSION_FNAME).srec
> 
> Could all this platform/board code be scrapped in favour of adding your
> system to the generic platform? There's some documentation over here
> which I hope to get in-tree soon:
> 
> https://paulburton.eu/kernel-docs/mips/generic-platform.html
> 
> You can also see some further examples of systems converted to the
> generic platform which I hope to get into mainline over the next few
> cycles over here:
> 
> https://git.linux-mips.org/cgit/linux-mti.git/log/
> 
> But the core of the generic platform is already there & ought to be
> usable for a system like this.
> 
> Thanks,
>     Paul

I think so, we aren't very different from the simpler MTI boards.  I was under
the mistaken impression that MIPS didn't have a generic platform like ARM, but
I'll give this a try along with the other changes you suggested now that I
know about it.

 Thanks,
     Nathan

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