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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
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+ d) Xilinx IP cores
+
+ The Xilinx EDK toolchain ships with a set of IP cores (devices) for use
+ in Xilinx Spartan and Virtex FPGAs. The devices cover the whole range
+ of standard device types (network, serial, etc.) and miscellaneous
+ devices (gpio, LCD, spi, etc). Also, since these devices are
+ implemented within the fpga fabric every instance of the device can be
+ synthesised with different options that change the behaviour.
+
+ Each IP-core has a set of parameters which the FPGA designer can use to
+ control how the core is synthesized. Historically, the EDK tool would
+ extract the device parameters relevant to device drivers and copy them
+ into an 'xparameters.h' in the form of #define symbols. This tells the
+ device drivers how the IP cores are configured, but it requires the kernel
+ to be recompiled every time the FPGA bitstream is resynthesized.
+
+ The new approach is to export the parameters into the device tree and
+ generate a new device tree each time the FPGA bitstream changes. The
+ parameters which used to be exported as #defines will now become
+ properties of the device node. In general, device nodes for IP-cores
+ will take the following form:
+
+ (name): (generic-name)@(base-address) {
+ compatible = "xlnx,(ip-core-name)-(HW_VER)"
+ [, (list of compatible devices), ...];
+ reg = <(baseaddr) (size)>;
+ interrupt-parent = <&interrupt-controller-phandle>;
+ interrupts = < ... >;
+ xlnx,(parameter1) = "(string-value)";
+ xlnx,(parameter2) = <(int-value)>;
+ };
+
+ (generic-name): an open firmware-style name that describes the
+ generic class of device. Preferably, this is one word, such
+ as 'serial' or 'ethernet'.
+ (ip-core-name): the name of the ip block (given after the BEGIN
+ directive in system.mhs). Should be in lowercase
+ and all underscores '_' converted to dashes '-'.
+ (name): is derived from the "PARAMETER INSTANCE" value.
+ (parameter#): C_* parameters from system.mhs. The C_ prefix is
+ dropped from the parameter name, the name is converted
+ to lowercase and all underscore '_' characters are
+ converted to dashes '-'.
+ (baseaddr): the baseaddr parameter value (often named C_BASEADDR).
+ (HW_VER): from the HW_VER parameter.
+ (size): the address range size (often C_HIGHADDR - C_BASEADDR + 1).
+
+ Typically, the compatible list will include the exact IP core version
+ followed by an older IP core version which implements the same
+ interface or any other device with the same interface.
+
+ 'reg' and 'interrupts' are all optional properties.
+
+ For example, the following block from system.mhs:
+
+ BEGIN opb_uartlite
+ PARAMETER INSTANCE = opb_uartlite_0
+ PARAMETER HW_VER = 1.00.b
+ PARAMETER C_BAUDRATE = 115200
+ PARAMETER C_DATA_BITS = 8
+ PARAMETER C_ODD_PARITY = 0
+ PARAMETER C_USE_PARITY = 0
+ PARAMETER C_CLK_FREQ = 50000000
+ PARAMETER C_BASEADDR = 0xEC100000
+ PARAMETER C_HIGHADDR = 0xEC10FFFF
+ BUS_INTERFACE SOPB = opb_7
+ PORT OPB_Clk = CLK_50MHz
+ PORT Interrupt = opb_uartlite_0_Interrupt
+ PORT RX = opb_uartlite_0_RX
+ PORT TX = opb_uartlite_0_TX
+ PORT OPB_Rst = sys_bus_reset_0
+ END
+
+ becomes the following device tree node:
+
+ opb_uartlite_0: serial@ec100000 {
+ device_type = "serial";
+ compatible = "xlnx,opb-uartlite-1.00.b";
+ reg = <ec100000 10000>;
+ interrupt-parent = <&opb_intc_0>;
+ interrupts = <1 0>; // got this from the opb_intc parameters
+ current-speed = <d#115200>; // standard serial device prop
+ clock-frequency = <d#50000000>; // standard serial device prop
+ xlnx,data-bits = <8>;
+ xlnx,odd-parity = <0>;
+ xlnx,use-parity = <0>;
+ };
+
+ That covers the general approach to binding xilinx IP cores into the
+ device tree. The following are bindings for specific devices:
+
+ i) Xilinx ML300 Framebuffer
+
+ Simple framebuffer device from the ML300 reference design (also on the
+ ML403 reference design as well as others).
+
+ Optional properties:
+ - resolution = <xres yres> : pixel resolution of framebuffer. Some
+ implementations use a different resolution.
+ Default is <d#640 d#480>
+ - virt-resolution = <xvirt yvirt> : Size of framebuffer in memory.
+ Default is <d#1024 d#480>.
+ - rotate-display (empty) : rotate display 180 degrees.
+
+ ii) Xilinx SystemACE
+
+ The Xilinx SystemACE device is used to program FPGAs from an FPGA
+ bitstream stored on a CF card. It can also be used as a generic CF
+ interface device.
+
+ Optional properties:
+ - 8-bit (empty) : Set this property for SystemACE in 8 bit mode
+
+ iii) Xilinx EMAC and Xilinx TEMAC
+
+ Xilinx Ethernet devices. In addition to general xilinx properties
+ listed above, nodes for these devices should include a phy-handle
+ property, and may include other common network device properties
+ like local-mac-address.
+
+ iv) Xilinx Uartlite
+
+ Xilinx uartlite devices are simple fixed speed serial ports.
+
+ Required properties:
+ - current-speed : Baud rate of uartlite
+
+ v) Xilinx hwicap
+
+ Xilinx hwicap devices provide access to the configuration logic
+ of the FPGA through the Internal Configuration Access Port
+ (ICAP). The ICAP enables partial reconfiguration of the FPGA,
+ readback of the configuration information, and some control over
+ 'warm boots' of the FPGA fabric.
+
+ Required properties:
+ - xlnx,family : The family of the FPGA, necessary since the
+ capabilities of the underlying ICAP hardware
+ differ between different families. May be
+ 'virtex2p', 'virtex4', or 'virtex5'.
+ - compatible : should contain "xlnx,xps-hwicap-1.00.a" or
+ "xlnx,opb-hwicap-1.00.b".
+
+ vi) Xilinx Uart 16550
+
+ Xilinx UART 16550 devices are very similar to the NS16550 but with
+ different register spacing and an offset from the base address.
+
+ Required properties:
+ - clock-frequency : Frequency of the clock input
+ - reg-offset : A value of 3 is required
+ - reg-shift : A value of 2 is required
+
+ vii) Xilinx USB Host controller
+
+ The Xilinx USB host controller is EHCI compatible but with a different
+ base address for the EHCI registers, and it is always a big-endian
+ USB Host controller. The hardware can be configured as high speed only,
+ or high speed/full speed hybrid.
+
+ Required properties:
+ - xlnx,support-usb-fs: A value 0 means the core is built as high speed
+ only. A value 1 means the core also supports
+ full speed devices.
+