mirror of
https://github.com/torvalds/linux.git
synced 2024-11-24 21:21:41 +00:00
d524dac927
The device tree is used by more than just PowerPC. Make the documentation
directory available to all.
v2: reorganized files while moving to create arch and driver specific
directories.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
307 lines
10 KiB
Plaintext
307 lines
10 KiB
Plaintext
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', '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: 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>;
|
|
};
|
|
|
|
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. In addition, the parent node should be
|
|
compatible with the bus type 'xlnx,compound', and should contain
|
|
#address-cells and #size-cells, as with any other bus. (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: opb-ps2-dual-ref@a9000000 {
|
|
#address-cells = <1>;
|
|
#size-cells = <1>;
|
|
compatible = "xlnx,compound";
|
|
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_0>;
|
|
interrupts = <3 0>;
|
|
cell-index = <0>;
|
|
};
|
|
ps2@1000 {
|
|
compatible = "xlnx,opb-ps2-dual-ref-1.00.a";
|
|
reg = <1000 40>;
|
|
interrupt-parent = <&opb_intc_0>;
|
|
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@0 {
|
|
#address-cells = <1>;
|
|
#size-cells = <1>;
|
|
compatible = "xlnx,plb-v34-1.02.a";
|
|
device_type = "ibm,plb";
|
|
ranges; // 1:1 translation
|
|
|
|
plb_bram_if_cntrl_0: bram@ffff0000 {
|
|
reg = <ffff0000 10000>;
|
|
}
|
|
|
|
opb@20000000 {
|
|
#address-cells = <1>;
|
|
#size-cells = <1>;
|
|
ranges = <20000000 20000000 20000000
|
|
60000000 60000000 20000000
|
|
80000000 80000000 40000000
|
|
c0000000 c0000000 20000000>;
|
|
|
|
opb_uart16550_0: serial@a0000000 {
|
|
reg = <a00000000 2000>;
|
|
};
|
|
|
|
opb_intc_0: interrupt-controller@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.
|
|
|
|
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'.
|
|
|
|
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.
|
|
|