Booting the Linux/ppc kernel without Open Firmware
--------------------------------------------------
-
(c) 2005 Benjamin Herrenschmidt <benh at kernel.crashing.org>,
IBM Corp.
(c) 2005 Becky Bruce <becky.bruce at freescale.com>,
(c) 2006 MontaVista Software, Inc.
Flash chip node definition
+Table of Contents
+=================
+
+ I - Introduction
+ 1) Entry point for arch/powerpc
+ 2) Board support
+
+ II - The DT block format
+ 1) Header
+ 2) Device tree generalities
+ 3) Device tree "structure" block
+ 4) Device tree "strings" block
+
+ III - Required content of the device tree
+ 1) Note about cells and address representation
+ 2) Note about "compatible" properties
+ 3) Note about "name" properties
+ 4) Note about node and property names and character set
+ 5) Required nodes and properties
+ a) The root node
+ b) The /cpus node
+ c) The /cpus/* nodes
+ d) the /memory node(s)
+ e) The /chosen node
+ f) the /soc<SOCname> node
+
+ IV - "dtc", the device tree compiler
+
+ V - Recommendations for a bootloader
+
+ VI - System-on-a-chip devices and nodes
+ 1) Defining child nodes of an SOC
+ 2) Representing devices without a current OF specification
+ a) MDIO IO device
+ b) Gianfar-compatible ethernet nodes
+ c) PHY nodes
+ d) Interrupt controllers
+ e) I2C
+ f) Freescale SOC USB controllers
+ g) Freescale SOC SEC Security Engines
+ h) Board Control and Status (BCSR)
+ i) Freescale QUICC Engine module (QE)
+ j) CFI or JEDEC memory-mapped NOR flash
+ k) Global Utilities Block
+ l) Freescale Communications Processor Module
+ m) Chipselect/Local Bus
+ n) 4xx/Axon EMAC ethernet nodes
+ o) Xilinx IP cores
+ p) Freescale Synchronous Serial Interface
+ q) USB EHCI controllers
+
+ VII - Specifying interrupt information for devices
+ 1) interrupts property
+ 2) interrupt-parent property
+ 3) OpenPIC Interrupt Controllers
+ 4) ISA Interrupt Controllers
+
+ Appendix A - Sample SOC node for MPC8540
+
+
+Revision Information
+====================
+
May 18, 2005: Rev 0.1 - Initial draft, no chapter III yet.
May 19, 2005: Rev 0.2 - Add chapter III and bits & pieces here or
and property data. The old style variable
alignment would make it impossible to do
"simple" insertion of properties using
- memove (thanks Milton for
+ memmove (thanks Milton for
noticing). Updated kernel patch as well
- Correct a few more alignment constraints
- Add a chapter about the device-tree
ToDo:
- Add some definitions of interrupt tree (simple/complex)
- - Add some definitions for pci host bridges
+ - Add some definitions for PCI host bridges
- Add some common address format examples
- Add definitions for standard properties and "compatible"
names for cells that are not already defined by the existing
forth words isn't required), you can enter the kernel with:
r5 : OF callback pointer as defined by IEEE 1275
- bindings to powerpc. Only the 32 bit client interface
+ bindings to powerpc. Only the 32-bit client interface
is currently supported
r3, r4 : address & length of an initrd if any or 0
for this is to keep kernels on embedded systems small and efficient;
part of this is due to the fact the code is already that way. In the
future, a kernel may support multiple platforms, but only if the
- platforms feature the same core architectire. A single kernel build
+ platforms feature the same core architecture. A single kernel build
cannot support both configurations with Book E and configurations
with classic Powerpc architectures.
enable another config option to select the specific board
supported.
-NOTE: If ben doesn't merge the setup files, may need to change this to
+NOTE: If Ben doesn't merge the setup files, may need to change this to
point to setup_32.c
u32 off_dt_struct; /* offset to structure */
u32 off_dt_strings; /* offset to strings */
u32 off_mem_rsvmap; /* offset to memory reserve map
-*/
+ */
u32 version; /* format version */
u32 last_comp_version; /* last compatible version */
booting on */
/* version 3 fields below */
u32 size_dt_strings; /* size of the strings block */
+
+ /* version 17 fields below */
+ u32 size_dt_struct; /* size of the DT structure block */
};
Along with the constants:
#define OF_DT_HEADER 0xd00dfeed /* 4: version,
4: total size */
#define OF_DT_BEGIN_NODE 0x1 /* Start node: full name
-*/
+ */
#define OF_DT_END_NODE 0x2 /* End node */
#define OF_DT_PROP 0x3 /* Property: name off,
size, content */
- off_mem_rsvmap
This is an offset from the beginning of the header to the start
- of the reserved memory map. This map is a list of pairs of 64
+ of the reserved memory map. This map is a list of pairs of 64-
bit integers. Each pair is a physical address and a size. The
-
list is terminated by an entry of size 0. This map provides the
kernel with a list of physical memory areas that are "reserved"
and thus not to be used for memory allocations, especially during
contain _at least_ this DT block itself (header,total_size). If
you are passing an initrd to the kernel, you should reserve it as
well. You do not need to reserve the kernel image itself. The map
- should be 64 bit aligned.
+ should be 64-bit aligned.
- version
to reallocate it easily at boot and free up the unused flattened
structure after expansion. Version 16 introduces a new more
"compact" format for the tree itself that is however not backward
- compatible. You should always generate a structure of the highest
- version defined at the time of your implementation. Currently
- that is version 16, unless you explicitly aim at being backward
- compatible.
+ compatible. Version 17 adds an additional field, size_dt_struct,
+ allowing it to be reallocated or moved more easily (this is
+ particularly useful for bootloaders which need to make
+ adjustments to a device tree based on probed information). You
+ should always generate a structure of the highest version defined
+ at the time of your implementation. Currently that is version 17,
+ unless you explicitly aim at being backward compatible.
- last_comp_version
is backward compatible with version 1 (that is, a kernel build
for version 1 will be able to boot with a version 2 format). You
should put a 1 in this field if you generate a device tree of
- version 1 to 3, or 0x10 if you generate a tree of version 0x10
+ version 1 to 3, or 16 if you generate a tree of version 16 or 17
using the new unit name format.
- boot_cpuid_phys
point (see further chapters for more informations on the required
device-tree contents)
+ - size_dt_strings
+
+ This field only exists on version 3 and later headers. It
+ gives the size of the "strings" section of the device tree (which
+ starts at the offset given by off_dt_strings).
+
+ - size_dt_struct
+
+ This field only exists on version 17 and later headers. It gives
+ the size of the "structure" section of the device tree (which
+ starts at the offset given by off_dt_struct).
So the typical layout of a DT block (though the various parts don't
need to be in that order) looks like this (addresses go from top to
A node has 2 names. The actual node name is generally contained in a
property of type "name" in the node property list whose value is a
zero terminated string and is mandatory for version 1 to 3 of the
-format definition (as it is in Open Firmware). Version 0x10 makes it
+format definition (as it is in Open Firmware). Version 16 makes it
optional as it can generate it from the unit name defined below.
There is also a "unit name" that is used to differentiate nodes with
interrupt tree which will be described in a further version of this
document.
-This "linux, phandle" property is a 32 bit value that uniquely
+This "linux, phandle" property is a 32-bit value that uniquely
identifies a node. You are free to use whatever values or system of
values, internal pointers, or whatever to generate these, the only
requirement is that every node for which you provide that property has
designates a node followed by the node unit name. Properties are
presented with their name followed by their content. "content"
represents an ASCII string (zero terminated) value, while <content>
-represents a 32 bit hexadecimal value. The various nodes in this
+represents a 32-bit hexadecimal value. The various nodes in this
example will be discussed in a later chapter. At this point, it is
only meant to give you a idea of what a device-tree looks like. I have
purposefully kept the "name" and "linux,phandle" properties which
* [align gap to next 4 bytes boundary]
* for each property:
* token OF_DT_PROP (that is 0x00000003)
- * 32 bit value of property value size in bytes (or 0 of no
- * value)
- * 32 bit value of offset in string block of property name
+ * 32-bit value of property value size in bytes (or 0 if no
+ value)
+ * 32-bit value of offset in string block of property name
* property value data if any
* [align gap to next 4 bytes boundary]
* [child nodes if any]
* token OF_DT_END_NODE (that is 0x00000002)
-So the node content can be summarised as a start token, a full path,
+So the node content can be summarized as a start token, a full path,
a list of properties, a list of child nodes, and an end token. Every
child node is a full node structure itself as defined above.
+NOTE: The above definition requires that all property definitions for
+a particular node MUST precede any subnode definitions for that node.
+Although the structure would not be ambiguous if properties and
+subnodes were intermingled, the kernel parser requires that the
+properties come first (up until at least 2.6.22). Any tools
+manipulating a flattened tree must take care to preserve this
+constraint.
+
4) Device tree "strings" block
In order to save space, property names, which are generally redundant,
----------------------------------------------
The general rule is documented in the various Open Firmware
-documentations. If you chose to describe a bus with the device-tree
+documentations. If you choose to describe a bus with the device-tree
and there exist an OF bus binding, then you should follow the
specification. However, the kernel does not require every single
device or bus to be described by the device tree.
In general, the format of an address for a device is defined by the
parent bus type, based on the #address-cells and #size-cells
-property. In the absence of such a property, the parent's parent
-values are used, etc... The kernel requires the root node to have
-those properties defining addresses format for devices directly mapped
-on the processor bus.
+properties. Note that the parent's parent definitions of #address-cells
+and #size-cells are not inhereted so every node with children must specify
+them. The kernel requires the root node to have those properties defining
+addresses format for devices directly mapped on the processor bus.
Those 2 properties define 'cells' for representing an address and a
-size. A "cell" is a 32 bit number. For example, if both contain 2
+size. A "cell" is a 32-bit number. For example, if both contain 2
like the example tree given above, then an address and a size are both
-composed of 2 cells, and each is a 64 bit number (cells are
+composed of 2 cells, and each is a 64-bit number (cells are
concatenated and expected to be in big endian format). Another example
is the way Apple firmware defines them, with 2 cells for an address
and one cell for a size. Most 32-bit implementations should define
like address space bits, you'll have to add a bus translator to the
prom_parse.c file of the recent kernels for your bus type.
-The "reg" property only defines addresses and sizes (if #size-cells
-is non-0) within a given bus. In order to translate addresses upward
-(that is into parent bus addresses, and possibly into cpu physical
+The "reg" property only defines addresses and sizes (if #size-cells is
+non-0) within a given bus. In order to translate addresses upward
+(that is into parent bus addresses, and possibly into CPU physical
addresses), all busses must contain a "ranges" property. If the
"ranges" property is missing at a given level, it's assumed that
-translation isn't possible. The format of the "ranges" property for a
-bus is a list of:
+translation isn't possible, i.e., the registers are not visible on the
+parent bus. The format of the "ranges" property for a bus is a list
+of:
bus address, parent bus address, size
PCI<->ISA bridge, that would be a PCI address. It defines the base
address in the parent bus where the beginning of that range is mapped.
-For a new 64 bit powerpc board, I recommend either the 2/2 format or
+For a new 64-bit powerpc board, I recommend either the 2/2 format or
Apple's 2/1 format which is slightly more compact since sizes usually
-fit in a single 32 bit word. New 32 bit powerpc boards should use a
+fit in a single 32-bit word. New 32-bit powerpc boards should use a
1/1 format, unless the processor supports physical addresses greater
than 32-bits, in which case a 2/1 format is recommended.
+Alternatively, the "ranges" property may be empty, indicating that the
+registers are visible on the parent bus using an identity mapping
+translation. In other words, the parent bus address space is the same
+as the child bus address space.
2) Note about "compatible" properties
-------------------------------------
Required properties:
- device_type : has to be "cpu"
- - reg : This is the physical cpu number, it's a single 32 bit cell
+ - reg : This is the physical CPU number, it's a single 32-bit cell
and is also used as-is as the unit number for constructing the
unit name in the full path. For example, with 2 CPUs, you would
have the full path:
/cpus/PowerPC,970FX@0
/cpus/PowerPC,970FX@1
(unit addresses do not require leading zeroes)
- - d-cache-line-size : one cell, L1 data cache line size in bytes
- - i-cache-line-size : one cell, L1 instruction cache line size in
+ - d-cache-block-size : one cell, L1 data cache block size in bytes (*)
+ - i-cache-block-size : one cell, L1 instruction cache block size in
bytes
- d-cache-size : one cell, size of L1 data cache in bytes
- i-cache-size : one cell, size of L1 instruction cache in bytes
+(*) The cache "block" size is the size on which the cache management
+instructions operate. Historically, this document used the cache
+"line" size here which is incorrect. The kernel will prefer the cache
+block size and will fallback to cache line size for backward
+compatibility.
+
Recommended properties:
- timebase-frequency : a cell indicating the frequency of the
the kernel timebase/decrementer calibration based on this
value.
- clock-frequency : a cell indicating the CPU core clock frequency
- in Hz. A new property will be defined for 64 bit values, but if
+ in Hz. A new property will be defined for 64-bit values, but if
your frequency is < 4Ghz, one cell is enough. Here as well as
for the above, the common code doesn't use that property, but
you are welcome to re-use the pSeries or Maple one. A future
kernel version might provide a common function for this.
+ - d-cache-line-size : one cell, L1 data cache line size in bytes
+ if different from the block size
+ - i-cache-line-size : one cell, L1 instruction cache line size in
+ bytes if different from the block size
You are welcome to add any property you find relevant to your board,
like some information about the mechanism used to soft-reset the
The SOC node may contain child nodes for each SOC device that the
platform uses. Nodes should not be created for devices which exist
on the SOC but are not used by a particular platform. See chapter VI
- for more information on how to specify devices that are part of an
-SOC.
+ for more information on how to specify devices that are part of a SOC.
Example SOC node for the MPC8540:
[-o output-filename] [-V output_version] input_filename
-The "output_version" defines what versio of the "blob" format will be
+The "output_version" defines what version of the "blob" format will be
generated. Supported versions are 1,2,3 and 16. The default is
currently version 3 but that may change in the future to version 16.
*/
property2 = <1234abcd>; /* define a property containing a
- * numerical 32 bits value (hexadecimal)
+ * numerical 32-bit value (hexadecimal)
*/
property3 = <12345678 12345678 deadbeef>;
/* define a property containing 3
- * numerical 32 bits values (cells) in
+ * numerical 32-bit values (cells) in
* hexadecimal
*/
property4 = [0a 0b 0c 0d de ea ad be ef];
its usage in early_init_devtree(), and the corresponding various
early_init_dt_scan_*() callbacks. That code can be re-used in a
GPL bootloader, and as the author of that code, I would be happy
- to discuss possible free licencing to any vendor who wishes to
+ to discuss possible free licensing to any vendor who wishes to
integrate all or part of this code into a non-GPL bootloader.
=======================================
Many companies are now starting to develop system-on-a-chip
-processors, where the processor core (cpu) and many peripheral devices
+processors, where the processor core (CPU) and many peripheral devices
exist on a single piece of silicon. For these SOCs, an SOC node
should be used that defines child nodes for the devices that make
up the SOC. While platforms are not required to use this model in
MPC8540.
-2) Specifying interrupt information for SOC devices
----------------------------------------------------
-
-Each device that is part of an SOC and which generates interrupts
-should have the following properties:
-
- - interrupt-parent : contains the phandle of the interrupt
- controller which handles interrupts for this device
- - interrupts : a list of tuples representing the interrupt
- number and the interrupt sense and level for each interrupt
- for this device.
-
-This information is used by the kernel to build the interrupt table
-for the interrupt controllers in the system.
-
-Sense and level information should be encoded as follows:
-
- Devices connected to openPIC-compatible controllers should encode
- sense and polarity as follows:
-
- 0 = low to high edge sensitive type enabled
- 1 = active low level sensitive type enabled
- 2 = active high level sensitive type enabled
- 3 = high to low edge sensitive type enabled
-
- ISA PIC interrupt controllers should adhere to the ISA PIC
- encodings listed below:
-
- 0 = active low level sensitive type enabled
- 1 = active high level sensitive type enabled
- 2 = high to low edge sensitive type enabled
- 3 = low to high edge sensitive type enabled
-
-
-
-3) Representing devices without a current OF specification
+2) Representing devices without a current OF specification
----------------------------------------------------------
Currently, there are many devices on SOCs that do not have a standard
Required properties:
- reg : Offset and length of the register set for the device
- - device_type : Should be "mdio"
- compatible : Should define the compatible device type for the
- mdio. Currently, this is most likely to be "gianfar"
+ mdio. Currently, this is most likely to be "fsl,gianfar-mdio"
Example:
mdio@24520 {
reg = <24520 20>;
- device_type = "mdio";
- compatible = "gianfar";
+ compatible = "fsl,gianfar-mdio";
ethernet-phy@0 {
......
services interrupts for this device.
- phy-handle : The phandle for the PHY connected to this ethernet
controller.
+ - fixed-link : <a b c d e> where a is emulated phy id - choose any,
+ but unique to the all specified fixed-links, b is duplex - 0 half,
+ 1 full, c is link speed - d#10/d#100/d#1000, d is pause - 0 no
+ pause, 1 pause, e is asym_pause - 0 no asym_pause, 1 asym_pause.
+
+ Recommended properties:
+
+ - linux,network-index : This is the intended "index" of this
+ network device. This is used by the bootwrapper to interpret
+ MAC addresses passed by the firmware when no information other
+ than indices is available to associate an address with a device.
+ - phy-connection-type : a string naming the controller/PHY interface type,
+ i.e., "mii" (default), "rmii", "gmii", "rgmii", "rgmii-id", "sgmii",
+ "tbi", or "rtbi". This property is only really needed if the connection
+ is of type "rgmii-id", as all other connection types are detected by
+ hardware.
+
Example:
and additions :
Required properties :
- - compatible : Should be "fsl-usb2-mph" for multi port host usb
- controllers, or "fsl-usb2-dr" for dual role usb controllers
- - phy_type : For multi port host usb controllers, should be one of
- "ulpi", or "serial". For dual role usb controllers, should be
+ - compatible : Should be "fsl-usb2-mph" for multi port host USB
+ controllers, or "fsl-usb2-dr" for dual role USB controllers
+ - phy_type : For multi port host USB controllers, should be one of
+ "ulpi", or "serial". For dual role USB controllers, should be
one of "ulpi", "utmi", "utmi_wide", or "serial".
- reg : Offset and length of the register set for the device
- port0 : boolean; if defined, indicates port0 is connected for
- interrupt-parent : the phandle for the interrupt controller that
services interrupts for this device.
- Example multi port host usb controller device node :
+ Example multi port host USB controller device node :
usb@22000 {
- device_type = "usb";
compatible = "fsl-usb2-mph";
reg = <22000 1000>;
#address-cells = <1>;
port1;
};
- Example dual role usb controller device node :
+ Example dual role USB controller device node :
usb@23000 {
- device_type = "usb";
compatible = "fsl-usb2-dr";
reg = <23000 1000>;
#address-cells = <1>;
- channel-fifo-len : An integer representing the number of
descriptor pointers each channel fetch fifo can hold.
- exec-units-mask : The bitmask representing what execution units
- (EUs) are available. It's a single 32 bit cell. EU information
+ (EUs) are available. It's a single 32-bit cell. EU information
should be encoded following the SEC's Descriptor Header Dword
EU_SEL0 field documentation, i.e. as follows:
bits 8 through 31 are reserved for future SEC EUs.
- descriptor-types-mask : The bitmask representing what descriptors
- are available. It's a single 32 bit cell. Descriptor type
+ are available. It's a single 32-bit cell. Descriptor type
information should be encoded following the SEC's Descriptor
Header Dword DESC_TYPE field documentation, i.e. as follows:
i) Freescale QUICC Engine module (QE)
This represents qe module that is installed on PowerQUICC II Pro.
- Hopefully it will merge backward compatibility with CPM/CPM2.
+
+ NOTE: This is an interim binding; it should be updated to fit
+ in with the CPM binding later in this document.
+
Basically, it is a bus of devices, that could act more or less
as a complete entity (UCC, USB etc ). All of them should be siblings on
the "root" qe node, using the common properties from there.
- The description below applies to the the qe of MPC8360 and
+ The description below applies to the qe of MPC8360 and
more nodes and properties would be extended in the future.
i) Root QE device
Required properties:
- - device_type : should be "qe";
+ - compatible : should be "fsl,qe";
- model : precise model of the QE, Can be "QE", "CPM", or "CPM2"
- reg : offset and length of the device registers.
- bus-frequency : the clock frequency for QUICC Engine.
#address-cells = <1>;
#size-cells = <1>;
#interrupt-cells = <2>;
- device_type = "qe";
- model = "QE";
+ compatible = "fsl,qe";
ranges = <0 e0100000 00100000>;
reg = <e0100000 480>;
brg-frequency = <0>;
ii) SPI (Serial Peripheral Interface)
Required properties:
- - device_type : should be "spi".
- - compatible : should be "fsl_spi".
- - mode : the spi operation mode, it can be "cpu" or "qe".
+ - cell-index : SPI controller index.
+ - compatible : should be "fsl,spi".
+ - mode : the SPI operation mode, it can be "cpu" or "cpu-qe".
- reg : Offset and length of the register set for the device
- interrupts : <a b> where a is the interrupt number and b is a
field that represents an encoding of the sense and level
Example:
spi@4c0 {
- device_type = "spi";
- compatible = "fsl_spi";
+ cell-index = <0>;
+ compatible = "fsl,spi";
reg = <4c0 40>;
interrupts = <82 0>;
interrupt-parent = <700>;
iii) USB (Universal Serial Bus Controller)
Required properties:
- - device_type : should be "usb".
- compatible : could be "qe_udc" or "fhci-hcd".
- mode : the could be "host" or "slave".
- reg : Offset and length of the register set for the device
Example(slave):
usb@6c0 {
- device_type = "usb";
compatible = "qe_udc";
reg = <6c0 40>;
interrupts = <8b 0>;
Required properties:
- device_type : should be "network", "hldc", "uart", "transparent"
- "bisync" or "atm".
+ "bisync", "atm", or "serial".
- compatible : could be "ucc_geth" or "fsl_atm" and so on.
- model : should be "UCC".
- device-id : the ucc number(1-8), corresponding to UCCx in UM.
- interrupt-parent : the phandle for the interrupt controller that
services interrupts for this device.
- pio-handle : The phandle for the Parallel I/O port configuration.
+ - port-number : for UART drivers, the port number to use, between 0 and 3.
+ This usually corresponds to the /dev/ttyQE device, e.g. <0> = /dev/ttyQE0.
+ The port number is added to the minor number of the device. Unlike the
+ CPM UART driver, the port-number is required for the QE UART driver.
+ - soft-uart : for UART drivers, if specified this means the QE UART device
+ driver should use "Soft-UART" mode, which is needed on some SOCs that have
+ broken UART hardware. Soft-UART is provided via a microcode upload.
+ - rx-clock-name: the UCC receive clock source
+ "none": clock source is disabled
+ "brg1" through "brg16": clock source is BRG1-BRG16, respectively
+ "clk1" through "clk24": clock source is CLK1-CLK24, respectively
+ - tx-clock-name: the UCC transmit clock source
+ "none": clock source is disabled
+ "brg1" through "brg16": clock source is BRG1-BRG16, respectively
+ "clk1" through "clk24": clock source is CLK1-CLK24, respectively
+ The following two properties are deprecated. rx-clock has been replaced
+ with rx-clock-name, and tx-clock has been replaced with tx-clock-name.
+ Drivers that currently use the deprecated properties should continue to
+ do so, in order to support older device trees, but they should be updated
+ to check for the new properties first.
- rx-clock : represents the UCC receive clock source.
0x00 : clock source is disabled;
0x1~0x10 : clock source is BRG1~BRG16 respectively;
- mac-address : list of bytes representing the ethernet address.
- phy-handle : The phandle for the PHY connected to this controller.
+ Recommended properties:
+ - linux,network-index : This is the intended "index" of this
+ network device. This is used by the bootwrapper to interpret
+ MAC addresses passed by the firmware when no information other
+ than indices is available to associate an address with a device.
+ - phy-connection-type : a string naming the controller/PHY interface type,
+ i.e., "mii" (default), "rmii", "gmii", "rgmii", "rgmii-id" (Internal
+ Delay), "rgmii-txid" (delay on TX only), "rgmii-rxid" (delay on RX only),
+ "tbi", or "rtbi".
+
Example:
ucc@2000 {
device_type = "network";
rx-clock = "none";
tx-clock = "clk9";
phy-handle = <212000>;
+ phy-connection-type = "gmii";
pio-handle = <140001>;
};
- assignment : function number of the pin according to the Pin Assignment
tables in User Manual. Each pin can have up to 4 possible functions in
QE and two options for CPM.
- - has_irq : indicates if the pin is used as source of exteral
+ - has_irq : indicates if the pin is used as source of external
interrupts.
Example:
vii) Multi-User RAM (MURAM)
Required properties:
- - device_type : should be "muram".
+ - compatible : should be "fsl,qe-muram", "fsl,cpm-muram".
- mode : the could be "host" or "slave".
- ranges : Should be defined as specified in 1) to describe the
translation of MURAM addresses.
Example:
muram@10000 {
- device_type = "muram";
+ compatible = "fsl,qe-muram", "fsl,cpm-muram";
ranges = <0 00010000 0000c000>;
data-only@0{
+ compatible = "fsl,qe-muram-data",
+ "fsl,cpm-muram-data";
reg = <0 c000>;
};
};
- g) Flash chip nodes
+ viii) Uploaded QE firmware
+
+ If a new firwmare has been uploaded to the QE (usually by the
+ boot loader), then a 'firmware' child node should be added to the QE
+ node. This node provides information on the uploaded firmware that
+ device drivers may need.
+
+ Required properties:
+ - id: The string name of the firmware. This is taken from the 'id'
+ member of the qe_firmware structure of the uploaded firmware.
+ Device drivers can search this string to determine if the
+ firmware they want is already present.
+ - extended-modes: The Extended Modes bitfield, taken from the
+ firmware binary. It is a 64-bit number represented
+ as an array of two 32-bit numbers.
+ - virtual-traps: The virtual traps, taken from the firmware binary.
+ It is an array of 8 32-bit numbers.
+
+ Example:
+
+ firmware {
+ id = "Soft-UART";
+ extended-modes = <0 0>;
+ virtual-traps = <0 0 0 0 0 0 0 0>;
+ }
+
+ j) CFI or JEDEC memory-mapped NOR flash
Flash chips (Memory Technology Devices) are often used for solid state
file systems on embedded devices.
+ - compatible : should contain the specific model of flash chip(s)
+ used, if known, followed by either "cfi-flash" or "jedec-flash"
+ - reg : Address range of the flash chip
+ - bank-width : Width (in bytes) of the flash bank. Equal to the
+ device width times the number of interleaved chips.
+ - device-width : (optional) Width of a single flash chip. If
+ omitted, assumed to be equal to 'bank-width'.
+ - #address-cells, #size-cells : Must be present if the flash has
+ sub-nodes representing partitions (see below). In this case
+ both #address-cells and #size-cells must be equal to 1.
+
+ For JEDEC compatible devices, the following additional properties
+ are defined:
+
+ - vendor-id : Contains the flash chip's vendor id (1 byte).
+ - device-id : Contains the flash chip's device id (1 byte).
+
+ In addition to the information on the flash bank itself, the
+ device tree may optionally contain additional information
+ describing partitions of the flash address space. This can be
+ used on platforms which have strong conventions about which
+ portions of the flash are used for what purposes, but which don't
+ use an on-flash partition table such as RedBoot.
+
+ Each partition is represented as a sub-node of the flash device.
+ Each node's name represents the name of the corresponding
+ partition of the flash device.
+
+ Flash partitions
+ - reg : The partition's offset and size within the flash bank.
+ - label : (optional) The label / name for this flash partition.
+ If omitted, the label is taken from the node name (excluding
+ the unit address).
+ - read-only : (optional) This parameter, if present, is a hint to
+ Linux that this flash partition should only be mounted
+ read-only. This is usually used for flash partitions
+ containing early-boot firmware images or data which should not
+ be clobbered.
+
+ Example:
+
+ flash@ff000000 {
+ compatible = "amd,am29lv128ml", "cfi-flash";
+ reg = <ff000000 01000000>;
+ bank-width = <4>;
+ device-width = <1>;
+ #address-cells = <1>;
+ #size-cells = <1>;
+ fs@0 {
+ label = "fs";
+ reg = <0 f80000>;
+ };
+ firmware@f80000 {
+ label ="firmware";
+ reg = <f80000 80000>;
+ read-only;
+ };
+ };
+
+ k) Global Utilities Block
+
+ The global utilities block controls power management, I/O device
+ enabling, power-on-reset configuration monitoring, general-purpose
+ I/O signal configuration, alternate function selection for multiplexed
+ signals, and clock control.
+
+ Required properties:
+
+ - compatible : Should define the compatible device type for
+ global-utilities.
+ - reg : Offset and length of the register set for the device.
+
+ Recommended properties:
+
+ - fsl,has-rstcr : Indicates that the global utilities register set
+ contains a functioning "reset control register" (i.e. the board
+ is wired to reset upon setting the HRESET_REQ bit in this register).
+
+ Example:
+
+ global-utilities@e0000 { /* global utilities block */
+ compatible = "fsl,mpc8548-guts";
+ reg = <e0000 1000>;
+ fsl,has-rstcr;
+ };
+
+ l) Freescale Communications Processor Module
+
+ NOTE: This is an interim binding, and will likely change slightly,
+ as more devices are supported. The QE bindings especially are
+ incomplete.
+
+ i) Root CPM node
+
+ Properties:
+ - compatible : "fsl,cpm1", "fsl,cpm2", or "fsl,qe".
+ - reg : A 48-byte region beginning with CPCR.
+
+ Example:
+ cpm@119c0 {
+ #address-cells = <1>;
+ #size-cells = <1>;
+ #interrupt-cells = <2>;
+ compatible = "fsl,mpc8272-cpm", "fsl,cpm2";
+ reg = <119c0 30>;
+ }
+
+ ii) Properties common to mulitple CPM/QE devices
+
+ - fsl,cpm-command : This value is ORed with the opcode and command flag
+ to specify the device on which a CPM command operates.
+
+ - fsl,cpm-brg : Indicates which baud rate generator the device
+ is associated with. If absent, an unused BRG
+ should be dynamically allocated. If zero, the
+ device uses an external clock rather than a BRG.
+
+ - reg : Unless otherwise specified, the first resource represents the
+ scc/fcc/ucc registers, and the second represents the device's
+ parameter RAM region (if it has one).
+
+ iii) Serial
+
+ Currently defined compatibles:
+ - fsl,cpm1-smc-uart
+ - fsl,cpm2-smc-uart
+ - fsl,cpm1-scc-uart
+ - fsl,cpm2-scc-uart
+ - fsl,qe-uart
+
+ Example:
+
+ serial@11a00 {
+ device_type = "serial";
+ compatible = "fsl,mpc8272-scc-uart",
+ "fsl,cpm2-scc-uart";
+ reg = <11a00 20 8000 100>;
+ interrupts = <28 8>;
+ interrupt-parent = <&PIC>;
+ fsl,cpm-brg = <1>;
+ fsl,cpm-command = <00800000>;
+ };
+
+ iii) Network
+
+ Currently defined compatibles:
+ - fsl,cpm1-scc-enet
+ - fsl,cpm2-scc-enet
+ - fsl,cpm1-fec-enet
+ - fsl,cpm2-fcc-enet (third resource is GFEMR)
+ - fsl,qe-enet
+
+ Example:
+
+ ethernet@11300 {
+ device_type = "network";
+ compatible = "fsl,mpc8272-fcc-enet",
+ "fsl,cpm2-fcc-enet";
+ reg = <11300 20 8400 100 11390 1>;
+ local-mac-address = [ 00 00 00 00 00 00 ];
+ interrupts = <20 8>;
+ interrupt-parent = <&PIC>;
+ phy-handle = <&PHY0>;
+ linux,network-index = <0>;
+ fsl,cpm-command = <12000300>;
+ };
+
+ iv) MDIO
+
+ Currently defined compatibles:
+ fsl,pq1-fec-mdio (reg is same as first resource of FEC device)
+ fsl,cpm2-mdio-bitbang (reg is port C registers)
+
+ Properties for fsl,cpm2-mdio-bitbang:
+ fsl,mdio-pin : pin of port C controlling mdio data
+ fsl,mdc-pin : pin of port C controlling mdio clock
+
+ Example:
+
+ mdio@10d40 {
+ device_type = "mdio";
+ compatible = "fsl,mpc8272ads-mdio-bitbang",
+ "fsl,mpc8272-mdio-bitbang",
+ "fsl,cpm2-mdio-bitbang";
+ reg = <10d40 14>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+ fsl,mdio-pin = <12>;
+ fsl,mdc-pin = <13>;
+ };
+
+ v) Baud Rate Generators
+
+ Currently defined compatibles:
+ fsl,cpm-brg
+ fsl,cpm1-brg
+ fsl,cpm2-brg
+
+ Properties:
+ - reg : There may be an arbitrary number of reg resources; BRG
+ numbers are assigned to these in order.
+ - clock-frequency : Specifies the base frequency driving
+ the BRG.
+
+ Example:
+
+ brg@119f0 {
+ compatible = "fsl,mpc8272-brg",
+ "fsl,cpm2-brg",
+ "fsl,cpm-brg";
+ reg = <119f0 10 115f0 10>;
+ clock-frequency = <d#25000000>;
+ };
+
+ vi) Interrupt Controllers
+
+ Currently defined compatibles:
+ - fsl,cpm1-pic
+ - only one interrupt cell
+ - fsl,pq1-pic
+ - fsl,cpm2-pic
+ - second interrupt cell is level/sense:
+ - 2 is falling edge
+ - 8 is active low
+
+ Example:
+
+ interrupt-controller@10c00 {
+ #interrupt-cells = <2>;
+ interrupt-controller;
+ reg = <10c00 80>;
+ compatible = "mpc8272-pic", "fsl,cpm2-pic";
+ };
+
+ vii) USB (Universal Serial Bus Controller)
+
+ Properties:
+ - compatible : "fsl,cpm1-usb", "fsl,cpm2-usb", "fsl,qe-usb"
+
+ Example:
+ usb@11bc0 {
+ #address-cells = <1>;
+ #size-cells = <0>;
+ compatible = "fsl,cpm2-usb";
+ reg = <11b60 18 8b00 100>;
+ interrupts = <b 8>;
+ interrupt-parent = <&PIC>;
+ fsl,cpm-command = <2e600000>;
+ };
+
+ viii) Multi-User RAM (MURAM)
+
+ The multi-user/dual-ported RAM is expressed as a bus under the CPM node.
+
+ Ranges must be set up subject to the following restrictions:
+
+ - Children's reg nodes must be offsets from the start of all muram, even
+ if the user-data area does not begin at zero.
+ - If multiple range entries are used, the difference between the parent
+ address and the child address must be the same in all, so that a single
+ mapping can cover them all while maintaining the ability to determine
+ CPM-side offsets with pointer subtraction. It is recommended that
+ multiple range entries not be used.
+ - A child address of zero must be translatable, even if no reg resources
+ contain it.
+
+ A child "data" node must exist, compatible with "fsl,cpm-muram-data", to
+ indicate the portion of muram that is usable by the OS for arbitrary
+ purposes. The data node may have an arbitrary number of reg resources,
+ all of which contribute to the allocatable muram pool.
+
+ Example, based on mpc8272:
+
+ muram@0 {
+ #address-cells = <1>;
+ #size-cells = <1>;
+ ranges = <0 0 10000>;
+
+ data@0 {
+ compatible = "fsl,cpm-muram-data";
+ reg = <0 2000 9800 800>;
+ };
+ };
+
+ m) Chipselect/Local Bus
+
+ Properties:
+ - name : Should be localbus
+ - #address-cells : Should be either two or three. The first cell is the
+ chipselect number, and the remaining cells are the
+ offset into the chipselect.
+ - #size-cells : Either one or two, depending on how large each chipselect
+ can be.
+ - ranges : Each range corresponds to a single chipselect, and cover
+ the entire access window as configured.
+
+ Example:
+ localbus@f0010100 {
+ compatible = "fsl,mpc8272-localbus",
+ "fsl,pq2-localbus";
+ #address-cells = <2>;
+ #size-cells = <1>;
+ reg = <f0010100 40>;
+
+ ranges = <0 0 fe000000 02000000
+ 1 0 f4500000 00008000>;
+
+ flash@0,0 {
+ compatible = "jedec-flash";
+ reg = <0 0 2000000>;
+ bank-width = <4>;
+ device-width = <1>;
+ };
+
+ board-control@1,0 {
+ reg = <1 0 20>;
+ compatible = "fsl,mpc8272ads-bcsr";
+ };
+ };
+
+
+ n) 4xx/Axon EMAC ethernet nodes
+
+ The EMAC ethernet controller in IBM and AMCC 4xx chips, and also
+ the Axon bridge. To operate this needs to interact with a ths
+ special McMAL DMA controller, and sometimes an RGMII or ZMII
+ interface. In addition to the nodes and properties described
+ below, the node for the OPB bus on which the EMAC sits must have a
+ correct clock-frequency property.
+
+ i) The EMAC node itself
+
+ Required properties:
+ - device_type : "network"
+
+ - compatible : compatible list, contains 2 entries, first is
+ "ibm,emac-CHIP" where CHIP is the host ASIC (440gx,
+ 405gp, Axon) and second is either "ibm,emac" or
+ "ibm,emac4". For Axon, thus, we have: "ibm,emac-axon",
+ "ibm,emac4"
+ - interrupts : <interrupt mapping for EMAC IRQ and WOL IRQ>
+ - interrupt-parent : optional, if needed for interrupt mapping
+ - reg : <registers mapping>
+ - local-mac-address : 6 bytes, MAC address
+ - mal-device : phandle of the associated McMAL node
+ - mal-tx-channel : 1 cell, index of the tx channel on McMAL associated
+ with this EMAC
+ - mal-rx-channel : 1 cell, index of the rx channel on McMAL associated
+ with this EMAC
+ - cell-index : 1 cell, hardware index of the EMAC cell on a given
+ ASIC (typically 0x0 and 0x1 for EMAC0 and EMAC1 on
+ each Axon chip)
+ - max-frame-size : 1 cell, maximum frame size supported in bytes
+ - rx-fifo-size : 1 cell, Rx fifo size in bytes for 10 and 100 Mb/sec
+ operations.
+ For Axon, 2048
+ - tx-fifo-size : 1 cell, Tx fifo size in bytes for 10 and 100 Mb/sec
+ operations.
+ For Axon, 2048.
+ - fifo-entry-size : 1 cell, size of a fifo entry (used to calculate
+ thresholds).
+ For Axon, 0x00000010
+ - mal-burst-size : 1 cell, MAL burst size (used to calculate thresholds)
+ in bytes.
+ For Axon, 0x00000100 (I think ...)
+ - phy-mode : string, mode of operations of the PHY interface.
+ Supported values are: "mii", "rmii", "smii", "rgmii",
+ "tbi", "gmii", rtbi", "sgmii".
+ For Axon on CAB, it is "rgmii"
+ - mdio-device : 1 cell, required iff using shared MDIO registers
+ (440EP). phandle of the EMAC to use to drive the
+ MDIO lines for the PHY used by this EMAC.
+ - zmii-device : 1 cell, required iff connected to a ZMII. phandle of
+ the ZMII device node
+ - zmii-channel : 1 cell, required iff connected to a ZMII. Which ZMII
+ channel or 0xffffffff if ZMII is only used for MDIO.
+ - rgmii-device : 1 cell, required iff connected to an RGMII. phandle
+ of the RGMII device node.
+ For Axon: phandle of plb5/plb4/opb/rgmii
+ - rgmii-channel : 1 cell, required iff connected to an RGMII. Which
+ RGMII channel is used by this EMAC.
+ Fox Axon: present, whatever value is appropriate for each
+ EMAC, that is the content of the current (bogus) "phy-port"
+ property.
+
+ Recommended properties:
+ - linux,network-index : This is the intended "index" of this
+ network device. This is used by the bootwrapper to interpret
+ MAC addresses passed by the firmware when no information other
+ than indices is available to associate an address with a device.
+
+ Optional properties:
+ - phy-address : 1 cell, optional, MDIO address of the PHY. If absent,
+ a search is performed.
+ - phy-map : 1 cell, optional, bitmap of addresses to probe the PHY
+ for, used if phy-address is absent. bit 0x00000001 is
+ MDIO address 0.
+ For Axon it can be absent, thouugh my current driver
+ doesn't handle phy-address yet so for now, keep
+ 0x00ffffff in it.
+ - rx-fifo-size-gige : 1 cell, Rx fifo size in bytes for 1000 Mb/sec
+ operations (if absent the value is the same as
+ rx-fifo-size). For Axon, either absent or 2048.
+ - tx-fifo-size-gige : 1 cell, Tx fifo size in bytes for 1000 Mb/sec
+ operations (if absent the value is the same as
+ tx-fifo-size). For Axon, either absent or 2048.
+ - tah-device : 1 cell, optional. If connected to a TAH engine for
+ offload, phandle of the TAH device node.
+ - tah-channel : 1 cell, optional. If appropriate, channel used on the
+ TAH engine.
+
+ Example:
+
+ EMAC0: ethernet@40000800 {
+ linux,network-index = <0>;
+ device_type = "network";
+ compatible = "ibm,emac-440gp", "ibm,emac";
+ interrupt-parent = <&UIC1>;
+ interrupts = <1c 4 1d 4>;
+ reg = <40000800 70>;
+ local-mac-address = [00 04 AC E3 1B 1E];
+ mal-device = <&MAL0>;
+ mal-tx-channel = <0 1>;
+ mal-rx-channel = <0>;
+ cell-index = <0>;
+ max-frame-size = <5dc>;
+ rx-fifo-size = <1000>;
+ tx-fifo-size = <800>;
+ phy-mode = "rmii";
+ phy-map = <00000001>;
+ zmii-device = <&ZMII0>;
+ zmii-channel = <0>;
+ };
+
+ ii) McMAL node
+
+ Required properties:
+ - device_type : "dma-controller"
+ - compatible : compatible list, containing 2 entries, first is
+ "ibm,mcmal-CHIP" where CHIP is the host ASIC (like
+ emac) and the second is either "ibm,mcmal" or
+ "ibm,mcmal2".
+ For Axon, "ibm,mcmal-axon","ibm,mcmal2"
+ - interrupts : <interrupt mapping for the MAL interrupts sources:
+ 5 sources: tx_eob, rx_eob, serr, txde, rxde>.
+ For Axon: This is _different_ from the current
+ firmware. We use the "delayed" interrupts for txeob
+ and rxeob. Thus we end up with mapping those 5 MPIC
+ interrupts, all level positive sensitive: 10, 11, 32,
+ 33, 34 (in decimal)
+ - dcr-reg : < DCR registers range >
+ - dcr-parent : if needed for dcr-reg
+ - num-tx-chans : 1 cell, number of Tx channels
+ - num-rx-chans : 1 cell, number of Rx channels
+
+ iii) ZMII node
+
+ Required properties:
+ - compatible : compatible list, containing 2 entries, first is
+ "ibm,zmii-CHIP" where CHIP is the host ASIC (like
+ EMAC) and the second is "ibm,zmii".
+ For Axon, there is no ZMII node.
+ - reg : <registers mapping>
+
+ iv) RGMII node
+
+ Required properties:
+ - compatible : compatible list, containing 2 entries, first is
+ "ibm,rgmii-CHIP" where CHIP is the host ASIC (like
+ EMAC) and the second is "ibm,rgmii".
+ For Axon, "ibm,rgmii-axon","ibm,rgmii"
+ - reg : <registers mapping>
+ - revision : as provided by the RGMII new version register if
+ available.
+ For Axon: 0x0000012a
+
+ o) 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): (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.
+
+ Requred properties:
+ - current-speed : Baud rate of uartlite
+
+ p) Freescale Synchronous Serial Interface
+
+ The SSI is a serial device that communicates with audio codecs. It can
+ be programmed in AC97, I2S, left-justified, or right-justified modes.
+
+ Required properties:
+ - compatible : compatible list, containing "fsl,ssi"
+ - cell-index : the SSI, <0> = SSI1, <1> = SSI2, and so on
+ - reg : offset and length of the register set for the device
+ - interrupts : <a b> where a is the interrupt number and b is a
+ field that represents an encoding of the sense and
+ level information for the interrupt. This should be
+ encoded based on the information in section 2)
+ depending on the type of interrupt controller you
+ have.
+ - interrupt-parent : the phandle for the interrupt controller that
+ services interrupts for this device.
+ - fsl,mode : the operating mode for the SSI interface
+ "i2s-slave" - I2S mode, SSI is clock slave
+ "i2s-master" - I2S mode, SSI is clock master
+ "lj-slave" - left-justified mode, SSI is clock slave
+ "lj-master" - l.j. mode, SSI is clock master
+ "rj-slave" - right-justified mode, SSI is clock slave
+ "rj-master" - r.j., SSI is clock master
+ "ac97-slave" - AC97 mode, SSI is clock slave
+ "ac97-master" - AC97 mode, SSI is clock master
+
+ Optional properties:
+ - codec-handle : phandle to a 'codec' node that defines an audio
+ codec connected to this SSI. This node is typically
+ a child of an I2C or other control node.
+
+ Child 'codec' node required properties:
+ - compatible : compatible list, contains the name of the codec
+
+ Child 'codec' node optional properties:
+ - clock-frequency : The frequency of the input clock, which typically
+ comes from an on-board dedicated oscillator.
+
+ * Freescale 83xx DMA Controller
+
+ Freescale PowerPC 83xx have on chip general purpose DMA controllers.
+
+ Required properties:
+
+ - compatible : compatible list, contains 2 entries, first is
+ "fsl,CHIP-dma", where CHIP is the processor
+ (mpc8349, mpc8360, etc.) and the second is
+ "fsl,elo-dma"
+ - reg : <registers mapping for DMA general status reg>
+ - ranges : Should be defined as specified in 1) to describe the
+ DMA controller channels.
+ - cell-index : controller index. 0 for controller @ 0x8100
+ - interrupts : <interrupt mapping for DMA IRQ>
+ - interrupt-parent : optional, if needed for interrupt mapping
+
+
+ - DMA channel nodes:
+ - compatible : compatible list, contains 2 entries, first is
+ "fsl,CHIP-dma-channel", where CHIP is the processor
+ (mpc8349, mpc8350, etc.) and the second is
+ "fsl,elo-dma-channel"
+ - reg : <registers mapping for channel>
+ - cell-index : dma channel index starts at 0.
+
+ Optional properties:
+ - interrupts : <interrupt mapping for DMA channel IRQ>
+ (on 83xx this is expected to be identical to
+ the interrupts property of the parent node)
+ - interrupt-parent : optional, if needed for interrupt mapping
+
+ Example:
+ dma@82a8 {
+ #address-cells = <1>;
+ #size-cells = <1>;
+ compatible = "fsl,mpc8349-dma", "fsl,elo-dma";
+ reg = <82a8 4>;
+ ranges = <0 8100 1a4>;
+ interrupt-parent = <&ipic>;
+ interrupts = <47 8>;
+ cell-index = <0>;
+ dma-channel@0 {
+ compatible = "fsl,mpc8349-dma-channel", "fsl,elo-dma-channel";
+ cell-index = <0>;
+ reg = <0 80>;
+ };
+ dma-channel@80 {
+ compatible = "fsl,mpc8349-dma-channel", "fsl,elo-dma-channel";
+ cell-index = <1>;
+ reg = <80 80>;
+ };
+ dma-channel@100 {
+ compatible = "fsl,mpc8349-dma-channel", "fsl,elo-dma-channel";
+ cell-index = <2>;
+ reg = <100 80>;
+ };
+ dma-channel@180 {
+ compatible = "fsl,mpc8349-dma-channel", "fsl,elo-dma-channel";
+ cell-index = <3>;
+ reg = <180 80>;
+ };
+ };
+
+ * Freescale 85xx/86xx DMA Controller
+
+ Freescale PowerPC 85xx/86xx have on chip general purpose DMA controllers.
+
Required properties:
- - device_type : has to be "rom"
- - compatible : Should specify what this flash device is compatible with.
- Currently, this is most likely to be "direct-mapped" (which
- corresponds to the MTD physmap mapping driver).
- - reg : Offset and length of the register set (or memory mapping) for
- the device.
- - bank-width : Width of the flash data bus in bytes. Required
- for the NOR flashes (compatible == "direct-mapped" and others) ONLY.
-
- Recommended properties :
-
- - partitions : Several pairs of 32-bit values where the first value is
- partition's offset from the start of the device and the second one is
- partition size in bytes with LSB used to signify a read only
- partition (so, the parition size should always be an even number).
- - partition-names : The list of concatenated zero terminated strings
- representing the partition names.
- - probe-type : The type of probe which should be done for the chip
- (JEDEC vs CFI actually). Valid ONLY for NOR flashes.
+ - compatible : compatible list, contains 2 entries, first is
+ "fsl,CHIP-dma", where CHIP is the processor
+ (mpc8540, mpc8540, etc.) and the second is
+ "fsl,eloplus-dma"
+ - reg : <registers mapping for DMA general status reg>
+ - cell-index : controller index. 0 for controller @ 0x21000,
+ 1 for controller @ 0xc000
+ - ranges : Should be defined as specified in 1) to describe the
+ DMA controller channels.
+
+ - DMA channel nodes:
+ - compatible : compatible list, contains 2 entries, first is
+ "fsl,CHIP-dma-channel", where CHIP is the processor
+ (mpc8540, mpc8560, etc.) and the second is
+ "fsl,eloplus-dma-channel"
+ - cell-index : dma channel index starts at 0.
+ - reg : <registers mapping for channel>
+ - interrupts : <interrupt mapping for DMA channel IRQ>
+ - interrupt-parent : optional, if needed for interrupt mapping
+
+ Example:
+ dma@21300 {
+ #address-cells = <1>;
+ #size-cells = <1>;
+ compatible = "fsl,mpc8540-dma", "fsl,eloplus-dma";
+ reg = <21300 4>;
+ ranges = <0 21100 200>;
+ cell-index = <0>;
+ dma-channel@0 {
+ compatible = "fsl,mpc8540-dma-channel", "fsl,eloplus-dma-channel";
+ reg = <0 80>;
+ cell-index = <0>;
+ interrupt-parent = <&mpic>;
+ interrupts = <14 2>;
+ };
+ dma-channel@80 {
+ compatible = "fsl,mpc8540-dma-channel", "fsl,eloplus-dma-channel";
+ reg = <80 80>;
+ cell-index = <1>;
+ interrupt-parent = <&mpic>;
+ interrupts = <15 2>;
+ };
+ dma-channel@100 {
+ compatible = "fsl,mpc8540-dma-channel", "fsl,eloplus-dma-channel";
+ reg = <100 80>;
+ cell-index = <2>;
+ interrupt-parent = <&mpic>;
+ interrupts = <16 2>;
+ };
+ dma-channel@180 {
+ compatible = "fsl,mpc8540-dma-channel", "fsl,eloplus-dma-channel";
+ reg = <180 80>;
+ cell-index = <3>;
+ interrupt-parent = <&mpic>;
+ interrupts = <17 2>;
+ };
+ };
+
+ * Freescale 8xxx/3.0 Gb/s SATA nodes
+
+ SATA nodes are defined to describe on-chip Serial ATA controllers.
+ Each SATA port should have its own node.
+
+ Required properties:
+ - compatible : compatible list, contains 2 entries, first is
+ "fsl,CHIP-sata", where CHIP is the processor
+ (mpc8315, mpc8379, etc.) and the second is
+ "fsl,pq-sata"
+ - interrupts : <interrupt mapping for SATA IRQ>
+ - cell-index : controller index.
+ 1 for controller @ 0x18000
+ 2 for controller @ 0x19000
+ 3 for controller @ 0x1a000
+ 4 for controller @ 0x1b000
+
+ Optional properties:
+ - interrupt-parent : optional, if needed for interrupt mapping
+ - reg : <registers mapping>
Example:
- flash@ff000000 {
- device_type = "rom";
- compatible = "direct-mapped";
- probe-type = "CFI";
- reg = <ff000000 01000000>;
- bank-width = <4>;
- partitions = <00000000 00f80000
- 00f80000 00080001>;
- partition-names = "fs\0firmware";
- };
+ sata@18000 {
+ compatible = "fsl,mpc8379-sata", "fsl,pq-sata";
+ reg = <0x18000 0x1000>;
+ cell-index = <1>;
+ interrupts = <2c 8>;
+ interrupt-parent = < &ipic >;
+ };
+
+ q) USB EHCI controllers
+
+ Required properties:
+ - compatible : should be "usb-ehci".
+ - reg : should contain at least address and length of the standard EHCI
+ register set for the device. Optional platform-dependent registers
+ (debug-port or other) can be also specified here, but only after
+ definition of standard EHCI registers.
+ - interrupts : one EHCI interrupt should be described here.
+ If device registers are implemented in big endian mode, the device
+ node should have "big-endian-regs" property.
+ If controller implementation operates with big endian descriptors,
+ "big-endian-desc" property should be specified.
+ If both big endian registers and descriptors are used by the controller
+ implementation, "big-endian" property can be specified instead of having
+ both "big-endian-regs" and "big-endian-desc".
+
+ Example (Sequoia 440EPx):
+ ehci@e0000300 {
+ compatible = "ibm,usb-ehci-440epx", "usb-ehci";
+ interrupt-parent = <&UIC0>;
+ interrupts = <1a 4>;
+ reg = <0 e0000300 90 0 e0000390 70>;
+ big-endian;
+ };
+
More devices will be defined as this spec matures.
+VII - Specifying interrupt information for devices
+===================================================
+
+The device tree represents the busses and devices of a hardware
+system in a form similar to the physical bus topology of the
+hardware.
+
+In addition, a logical 'interrupt tree' exists which represents the
+hierarchy and routing of interrupts in the hardware.
+
+The interrupt tree model is fully described in the
+document "Open Firmware Recommended Practice: Interrupt
+Mapping Version 0.9". The document is available at:
+<http://playground.sun.com/1275/practice>.
+
+1) interrupts property
+----------------------
+
+Devices that generate interrupts to a single interrupt controller
+should use the conventional OF representation described in the
+OF interrupt mapping documentation.
+
+Each device which generates interrupts must have an 'interrupt'
+property. The interrupt property value is an arbitrary number of
+of 'interrupt specifier' values which describe the interrupt or
+interrupts for the device.
+
+The encoding of an interrupt specifier is determined by the
+interrupt domain in which the device is located in the
+interrupt tree. The root of an interrupt domain specifies in
+its #interrupt-cells property the number of 32-bit cells
+required to encode an interrupt specifier. See the OF interrupt
+mapping documentation for a detailed description of domains.
+
+For example, the binding for the OpenPIC interrupt controller
+specifies an #interrupt-cells value of 2 to encode the interrupt
+number and level/sense information. All interrupt children in an
+OpenPIC interrupt domain use 2 cells per interrupt in their interrupts
+property.
+
+The PCI bus binding specifies a #interrupt-cell value of 1 to encode
+which interrupt pin (INTA,INTB,INTC,INTD) is used.
+
+2) interrupt-parent property
+----------------------------
+
+The interrupt-parent property is specified to define an explicit
+link between a device node and its interrupt parent in
+the interrupt tree. The value of interrupt-parent is the
+phandle of the parent node.
+
+If the interrupt-parent property is not defined for a node, it's
+interrupt parent is assumed to be an ancestor in the node's
+_device tree_ hierarchy.
+
+3) OpenPIC Interrupt Controllers
+--------------------------------
+
+OpenPIC interrupt controllers require 2 cells to encode
+interrupt information. The first cell defines the interrupt
+number. The second cell defines the sense and level
+information.
+
+Sense and level information should be encoded as follows:
+
+ 0 = low to high edge sensitive type enabled
+ 1 = active low level sensitive type enabled
+ 2 = active high level sensitive type enabled
+ 3 = high to low edge sensitive type enabled
+
+4) ISA Interrupt Controllers
+----------------------------
+
+ISA PIC interrupt controllers require 2 cells to encode
+interrupt information. The first cell defines the interrupt
+number. The second cell defines the sense and level
+information.
+
+ISA PIC interrupt controllers should adhere to the ISA PIC
+encodings listed below:
+
+ 0 = active low level sensitive type enabled
+ 1 = active high level sensitive type enabled
+ 2 = high to low edge sensitive type enabled
+ 3 = low to high edge sensitive type enabled
+
Appendix A - Sample SOC node for MPC8540
========================================
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff