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| -rw-r--r-- | Documentation/powerpc/booting-without-of.txt | 261 |
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diff --git a/Documentation/powerpc/booting-without-of.txt b/Documentation/powerpc/booting-without-of.txt index a96e853..59df69d 100644 --- a/Documentation/powerpc/booting-without-of.txt +++ b/Documentation/powerpc/booting-without-of.txt @@ -52,6 +52,7 @@ Table of Contents i) Freescale QUICC Engine module (QE) j) CFI or JEDEC memory-mapped NOR flash k) Global Utilities Block + l) Xilinx IP cores VII - Specifying interrupt information for devices 1) interrupts property @@ -2242,6 +2243,266 @@ platforms are moved over to use the flattened-device-tree model. available. For Axon: 0x0000012a + l) 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 miscellanious + 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 requres 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)@(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)>; + }; + + (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 C_BASEADDR parameter. + (HW_VER): from the HW_VER parameter. + (size): equals 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', 'interrupt-parent' 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@ec100000 { + device_type = "serial"; + compatible = "xlnx,opb-uartlite-1.00.b"; + reg = <ec100000 10000>; + interrupt-parent = <&opb-intc>; + 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>; + }; + + Some IP cores actually implement 2 or more logical devices. In this case, + the device should still describe the whole IP core with a single node + and add a child node for each logical device. The ranges property can + be used to translate from parent IP-core to the registers of each device. + (Note: this makes the assumption that both logical devices have the same + bus binding. If this is not true, then separate nodes should be used for + each logical device). The 'cell-index' property can be used to enumerate + logical devices within an IP core. For example, the following is the + system.mhs entry for the dual ps2 controller found on the ml403 reference + design. + + BEGIN opb_ps2_dual_ref + PARAMETER INSTANCE = opb_ps2_dual_ref_0 + PARAMETER HW_VER = 1.00.a + PARAMETER C_BASEADDR = 0xA9000000 + PARAMETER C_HIGHADDR = 0xA9001FFF + BUS_INTERFACE SOPB = opb_v20_0 + PORT Sys_Intr1 = ps2_1_intr + PORT Sys_Intr2 = ps2_2_intr + PORT Clkin1 = ps2_clk_rx_1 + PORT Clkin2 = ps2_clk_rx_2 + PORT Clkpd1 = ps2_clk_tx_1 + PORT Clkpd2 = ps2_clk_tx_2 + PORT Rx1 = ps2_d_rx_1 + PORT Rx2 = ps2_d_rx_2 + PORT Txpd1 = ps2_d_tx_1 + PORT Txpd2 = ps2_d_tx_2 + END + + It would result in the following device tree nodes: + + opb_ps2_dual_ref_0@a9000000 { + ranges = <0 a9000000 2000>; + // If this device had extra parameters, then they would + // go here. + ps2@0 { + compatible = "xlnx,opb-ps2-dual-ref-1.00.a"; + reg = <0 40>; + interrupt-parent = <&opb-intc>; + interrupts = <3 0>; + cell-index = <0>; + }; + ps2@1000 { + compatible = "xlnx,opb-ps2-dual-ref-1.00.a"; + reg = <1000 40>; + interrupt-parent = <&opb-intc>; + interrupts = <3 0>; + cell-index = <0>; + }; + }; + + Also, the system.mhs file defines bus attachments from the processor + to the devices. The device tree structure should reflect the bus + attachments. Again an example; this system.mhs fragment: + + BEGIN ppc405_virtex4 + PARAMETER INSTANCE = ppc405_0 + PARAMETER HW_VER = 1.01.a + BUS_INTERFACE DPLB = plb_v34_0 + BUS_INTERFACE IPLB = plb_v34_0 + END + + BEGIN opb_intc + PARAMETER INSTANCE = opb_intc_0 + PARAMETER HW_VER = 1.00.c + PARAMETER C_BASEADDR = 0xD1000FC0 + PARAMETER C_HIGHADDR = 0xD1000FDF + BUS_INTERFACE SOPB = opb_v20_0 + END + + BEGIN opb_uart16550 + PARAMETER INSTANCE = opb_uart16550_0 + PARAMETER HW_VER = 1.00.d + PARAMETER C_BASEADDR = 0xa0000000 + PARAMETER C_HIGHADDR = 0xa0001FFF + BUS_INTERFACE SOPB = opb_v20_0 + END + + BEGIN plb_v34 + PARAMETER INSTANCE = plb_v34_0 + PARAMETER HW_VER = 1.02.a + END + + BEGIN plb_bram_if_cntlr + PARAMETER INSTANCE = plb_bram_if_cntlr_0 + PARAMETER HW_VER = 1.00.b + PARAMETER C_BASEADDR = 0xFFFF0000 + PARAMETER C_HIGHADDR = 0xFFFFFFFF + BUS_INTERFACE SPLB = plb_v34_0 + END + + BEGIN plb2opb_bridge + PARAMETER INSTANCE = plb2opb_bridge_0 + PARAMETER HW_VER = 1.01.a + PARAMETER C_RNG0_BASEADDR = 0x20000000 + PARAMETER C_RNG0_HIGHADDR = 0x3FFFFFFF + PARAMETER C_RNG1_BASEADDR = 0x60000000 + PARAMETER C_RNG1_HIGHADDR = 0x7FFFFFFF + PARAMETER C_RNG2_BASEADDR = 0x80000000 + PARAMETER C_RNG2_HIGHADDR = 0xBFFFFFFF + PARAMETER C_RNG3_BASEADDR = 0xC0000000 + PARAMETER C_RNG3_HIGHADDR = 0xDFFFFFFF + BUS_INTERFACE SPLB = plb_v34_0 + BUS_INTERFACE MOPB = opb_v20_0 + END + + Gives this device tree (some properties removed for clarity): + + plb-v34-0 { + #address-cells = <1>; + #size-cells = <1>; + device_type = "ibm,plb"; + ranges; // 1:1 translation + + plb-bram-if-cntrl-0@ffff0000 { + reg = <ffff0000 10000>; + } + + opb-v20-0 { + #address-cells = <1>; + #size-cells = <1>; + ranges = <20000000 20000000 20000000 + 60000000 60000000 20000000 + 80000000 80000000 40000000 + c0000000 c0000000 20000000>; + + opb-uart16550-0@a0000000 { + reg = <a00000000 2000>; + }; + + opb-intc-0@d1000fc0 { + reg = <d1000fc0 20>; + }; + }; + }; + + 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. + + Requred properties: + - current-speed : Baud rate of uartlite + More devices will be defined as this spec matures. VII - Specifying interrupt information for devices |