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authorLinus Torvalds <torvalds@linux-foundation.org>2015-11-15 09:10:53 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2015-11-15 09:10:53 -0800
commitb84da9fa47cf6e8dfd71d673a2f744ec1cac452c (patch)
tree800a1cb1e939eb84f7e7018be64e94be5c972ca0 /Documentation
parent12b76f3bf336388916ddf8047156f9e9993ff4e9 (diff)
parentda34232641a91ca785a787c23c158488e459b938 (diff)
Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus
Pull MIPS updates from Ralf Baechle: "These are the highlists of the main MIPS pull request for 4.4: - Add latencytop support - Support appended DTBs - VDSO support and initially use it for gettimeofday. - Drop the .MIPS.abiflags and ELF NOTE sections from vmlinux - Support for the 5KE, an internal test core. - Switch all MIPS platfroms to libata drivers. - Improved support, cleanups for ralink and Lantiq platforms. - Support for the new xilfpga platform. - A number of DTB improvments for BMIPS. - Improved support for CM and CPS. - Minor JZ4740 and BCM47xx enhancements" * 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (120 commits) MIPS: idle: add case for CPU_5KE MIPS: Octeon: Support APPENDED_DTB MIPS: vmlinux: create a section for appended DTB MIPS: Clean up compat_siginfo_t MIPS: Fix PAGE_MASK definition MIPS: BMIPS: Enable GZIP ramdisk and timed printks MIPS: Add xilfpga defconfig MIPS: xilfpga: Add mipsfpga platform code MIPS: xilfpga: Add xilfpga device tree files. dt-bindings: MIPS: Document xilfpga bindings and boot style MIPS: Make MIPS_CMDLINE_DTB default MIPS: Make the kernel arguments from dtb available MIPS: Use USE_OF as the guard for appended dtb MIPS: BCM63XX: Use pr_* instead of printk MIPS: Loongson: Cleanup CONFIG_LOONGSON_SUSPEND. MIPS: lantiq: Disable xbar fpi burst mode MIPS: lantiq: Force the crossbar to big endian MIPS: lantiq: Initialize the USB core on boot MIPS: lantiq: Return correct value for fpi clock on ar9 MIPS: ralink: Add missing clock on rt305x ...
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/devicetree/bindings/mips/img/xilfpga.txt83
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+Imagination University Program MIPSfpga
+=======================================
+
+Under the Imagination University Program, a microAptiv UP core has been
+released for academic usage.
+
+As we are dealing with a MIPS core instantiated on an FPGA, specifications
+are fluid and can be varied in RTL.
+
+This binding document is provided as baseline guidance for the example
+project provided by IMG.
+
+The example project runs on the Nexys4DDR board by Digilent powered by
+the ARTIX-7 FPGA by Xilinx.
+
+Relevant details about the example project and the Nexys4DDR board:
+
+- microAptiv UP core m14Kc
+- 50MHz clock speed
+- 128Mbyte DDR RAM at 0x0000_0000
+- 8Kbyte RAM at 0x1000_0000
+- axi_intc at 0x1020_0000
+- axi_uart16550 at 0x1040_0000
+- axi_gpio at 0x1060_0000
+- axi_i2c at 0x10A0_0000
+- custom_gpio at 0x10C0_0000
+- axi_ethernetlite at 0x10E0_0000
+- 8Kbyte BootRAM at 0x1FC0_0000
+
+Required properties:
+--------------------
+ - compatible: Must include "digilent,nexys4ddr","img,xilfpga".
+
+CPU nodes:
+----------
+A "cpus" node is required. Required properties:
+ - #address-cells: Must be 1.
+ - #size-cells: Must be 0.
+A CPU sub-node is also required for at least CPU 0. Required properties:
+ - device_type: Must be "cpu".
+ - compatible: Must be "mips,m14Kc".
+ - reg: Must be <0>.
+ - clocks: phandle to ext clock for fixed-clock received by MIPS core.
+
+Example:
+
+ compatible = "img,xilfpga","digilent,nexys4ddr";
+ cpus {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ cpu0: cpu@0 {
+ device_type = "cpu";
+ compatible = "mips,m14Kc";
+ reg = <0>;
+ clocks = <&ext>;
+ };
+ };
+
+ ext: ext {
+ compatible = "fixed-clock";
+ #clock-cells = <0>;
+ clock-frequency = <50000000>;
+ };
+
+Boot protocol:
+--------------
+
+The BootRAM is a writeable "RAM" in FPGA at 0x1FC0_0000.
+This is for easy reprogrammibility via JTAG.
+
+The BootRAM initializes the cache and the axi_uart peripheral.
+
+DDR initialization is already handled by a HW IP block.
+
+When the example project bitstream is loaded, the cpu_reset button
+needs to be pressed.
+
+The bootram initializes the cache and axi_uart.
+Then outputs MIPSFPGA\n\r on the serial port on the Nexys4DDR board.
+
+At this point, the board is ready to load the Linux kernel
+vmlinux file via JTAG.