Patchwork [1/8] powerpc/5200: update device tree binding documentation

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Submitter Grant Likely
Date Jan. 21, 2009, 8:55 p.m.
Message ID <20090121205506.31232.27908.stgit@localhost.localdomain>
Download mbox | patch
Permalink /patch/19693/
State Superseded
Delegated to: Grant Likely
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Grant Likely - Jan. 21, 2009, 8:55 p.m.
From: Grant Likely <grant.likely@secretlab.ca>

This patch updates the mpc5200 binding documentation to match
actual usage conventions, to remove incorrect information, and
to remove topics which are more thoroughly described elsewhere.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
CC: devtree-discuss@ozlabs.org
CC: Wolfram Sang <w.sang@pengutronix.de>
---

 Documentation/powerpc/dts-bindings/fsl/mpc5200.txt |  181 +++++++++++++
 .../powerpc/mpc52xx-device-tree-bindings.txt       |  277 --------------------
 2 files changed, 181 insertions(+), 277 deletions(-)
 create mode 100644 Documentation/powerpc/dts-bindings/fsl/mpc5200.txt
 delete mode 100644 Documentation/powerpc/mpc52xx-device-tree-bindings.txt
Wolfram Sang - Jan. 25, 2009, 7:48 p.m.
Hello Grant,

On Wed, Jan 21, 2009 at 01:55:07PM -0700, Grant Likely wrote:
> From: Grant Likely <grant.likely@secretlab.ca>
> 
> This patch updates the mpc5200 binding documentation to match
> actual usage conventions, to remove incorrect information, and
> to remove topics which are more thoroughly described elsewhere.
> 
> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
> CC: devtree-discuss@ozlabs.org
> CC: Wolfram Sang <w.sang@pengutronix.de>
> ---
> 
>  Documentation/powerpc/dts-bindings/fsl/mpc5200.txt |  181 +++++++++++++
>  .../powerpc/mpc52xx-device-tree-bindings.txt       |  277 --------------------
>  2 files changed, 181 insertions(+), 277 deletions(-)
>  create mode 100644 Documentation/powerpc/dts-bindings/fsl/mpc5200.txt
>  delete mode 100644 Documentation/powerpc/mpc52xx-device-tree-bindings.txt
> 
> 
> diff --git a/Documentation/powerpc/dts-bindings/fsl/mpc5200.txt b/Documentation/powerpc/dts-bindings/fsl/mpc5200.txt
> new file mode 100644
> index 0000000..1eddda7
> --- /dev/null
> +++ b/Documentation/powerpc/dts-bindings/fsl/mpc5200.txt
> @@ -0,0 +1,181 @@
> +MPC5200 Device Tree Bindings
> +----------------------------
> +
> +(c) 2006-2009 Secret Lab Technologies Ltd
> +Grant Likely <grant.likely@secretlab.ca>
> +
> +Naming conventions
> +------------------
> +For mpc5200 on-chip devices, the format for each compatible value is
> +<chip>-<device>[-<mode>].  The OS should be able to match a device driver
> +to the device based solely on the compatible value.  If two drivers
> +match on the compatible list; the 'most compatible' driver should be
> +selected.
> +
> +The split between the MPC5200 and the MPC5200B leaves a bit of a
> +conundrum.  How should the compatible property be set up to provide
> +maximum compatibility information; but still accurately describe the
> +chip?  For the MPC5200; the answer is easy.  Most of the SoC devices
> +originally appeared on the MPC5200.  Since they didn't exist anywhere
> +else; the 5200 compatible properties will contain only one item;
> +"fsl,mpc5200-<device>".
> +
> +The 5200B is almost the same as the 5200, but not quite.  It fixes
> +silicon bugs and it adds a small number of enhancements.  Most of the
> +devices either provide exactly the same interface as on the 5200.  A few
> +devices have extra functions but still have a backwards compatible mode.
> +To express this information as completely as possible, 5200B device trees
> +should have two items in the compatible list:
> +	compatible = "fsl,mpc5200b-<device>","fsl,mpc5200-<device>";
> +
> +It is *strongly* recommended that 5200B device trees follow this convention
> +(instead of only listing the base mpc5200 item).
> +
> +ie. ethernet on mpc5200: compatible = "fsl,mpc5200-ethernet";
> +    ethernet on mpc5200b: compatible = "fsl,mpc5200b-ethernet",
> +                                       "fsl,mpc5200-ethernet";
> +
> +Modal devices, like PSCs, also append the configured function to the
> +end of the compatible field.  ie. A PSC in i2s mode would specify
> +"fsl,mpc5200-psc-i2s", not "fsl,mpc5200-i2s".  This convention is chosen to
> +avoid naming conflicts with non-psc devices providing the same
> +function.  For example, "fsl,mpc5200-spi" and "fsl,mpc5200-psc-spi" describe
> +the mpc5200 simple spi device and a PSC spi mode respectively.
> +
> +At the time of writing, exact chip may be either 'fsl,mpc5200' or
> +'fsl,mpc5200b'.
> +
> +The soc node
> +------------
> +This node describes the on chip SOC peripherals.  Every mpc5200 based
> +board will have this node, and as such there is a common naming
> +convention for SOC devices.
> +
> +Required properties:
> +name			description
> +----			-----------
> +ranges			Memory range of the internal memory mapped registers.
> +			Should be <0 [baseaddr] 0xc000>
> +reg			Should be <[baseaddr] 0x100>
> +compatible		mpc5200: "fsl,mpc5200-immr"
> +			mpc5200b: "fsl,mpc5200b-immr"
> +system-frequency	Fsystem frequency; source of all

Fsystem? Typo? The unit would be nice here, too, I think.

> +			other clocks.
> +bus-frequency		IPB bus frequency in HZ.  Clock rate
> +			used by most of the soc devices.
> +
> +soc child nodes
> +---------------
> +Any on chip SOC devices available to Linux must appear as soc5200 child nodes.
> +
> +Note: The tables below show the value for the mpc5200.  A mpc5200b device
> +tree should use the "fsl,mpc5200b-<device>","fsl,mpc5200-<device>" form.
> +
> +Required soc5200 child nodes:
> +name				compatible		Description
> +----				----------		-----------
> +cdm@<addr>			fsl,mpc5200-cmd		Clock Distribution

					     ^^ cdm!

> +interrupt-controller@<addr>	fsl,mpc5200-pic		need an interrupt
> +							controller to boot
> +bestcomm@<addr>			fsl,mpc5200-bestcomm	Bestcomm DMA controller
> +
> +Recommended soc5200 child nodes; populate as needed for your board
> +name		compatible		Description
> +----		----------		-----------
> +timer@<addr>	fsl,mpc5200-gpt		 General purpose timers
> +gpio@<addr>	fsl,mpc5200-gpio	 MPC5200 simple gpio controller
> +gpio@<addr>	fsl,mpc5200-gpio-wkup	 MPC5200 wakeup gpio controller
> +rtc@<addr>	fsl,mpc5200-rtc		 Real time clock
> +mscan@<addr>	fsl,mpc5200-mscan	 CAN bus controller
> +pci@<addr>	fsl,mpc5200-pci		 PCI bridge
> +serial@<addr>	fsl,mpc5200-psc-uart	 PSC in serial mode
> +i2s@<addr>	fsl,mpc5200-psc-i2s	 PSC in i2s mode
> +ac97@<addr>	fsl,mpc5200-psc-ac97	 PSC in ac97 mode
> +spi@<addr>	fsl,mpc5200-psc-spi	 PSC in spi mode
> +irda@<addr>	fsl,mpc5200-psc-irda	 PSC in IrDA mode
> +spi@<addr>	fsl,mpc5200-spi		 MPC5200 spi device
> +ethernet@<addr>	fsl,mpc5200-fec		 MPC5200 ethernet device
> +ata@<addr>	fsl,mpc5200-ata		 IDE ATA interface
> +i2c@<addr>	fsl,mpc5200-i2c		 I2C controller
> +usb@<addr>	fsl,mpc5200-ohci,ohci-be USB controller
> +xlb@<addr>	fsl,mpc5200-xlb		 XLB arbitrator
> +
> +fsl,mpc5200-gpt nodes
> +---------------------
> +On the mpc5200 and 5200b, GPT0 has a watchdog timer function.  If the board
> +design supports the internal wdt, then the device node for GPT0 should
> +include the empty property 'fsl,has-wdt'.
> +
> +An mpc5200-gpt can be used as a single line GPIO controller.  To do so,
> +add the following properties to the gpt node:
> +	gpio-controller;
> +	#gpio-cells = <2>;
> +When referencing the GPIO line from another node, the first cell must always
> +be zero and the second cell represents the gpio flags and described in the
> +gpio device tree binding.
> +
> +An mpc5200-gpt can be used as a single line edge sensitive interrupt
> +controller.  To do so, add the following properties to the gpt node:
> +	interrupt-controller;
> +	#interrupt-cells = <1>;
> +When referencing the IRQ line from another node, the cell represents the
> +sense mode; 1 for edge rising, 2 for edge falling.
> +
> +fsl,mpc5200-psc nodes
> +---------------------
> +The PSCs should include a cell-index which is the index of the PSC in
> +hardware.  cell-index is used to determine which shared SoC registers to
> +use when setting up PSC clocking.  cell-index number starts at '0'.  ie:
> +	PSC1 has 'cell-index = <0>'
> +	PSC4 has 'cell-index = <3>'
> +
> +PSC in i2s mode:  The mpc5200 and mpc5200b PSCs are not compatible when in
> +i2s mode.  An 'mpc5200b-psc-i2s' node cannot include 'mpc5200-psc-i2s' in the
> +compatible field.
> +
> +
> +fsl,mpc5200-gpio and fsl,mpc5200-gpio-wkup nodes
> +------------------------------------------------
> +Each GPIO controller node should have the empty property gpio-controller and
> +#gpio-cells set to 2. First cell is the GPIO number which is interpreted
> +according to the bit numbers in the GPIO control registers. The second cell
> +is for flags which is currently unsused.

Typo: should be "unused".

> +
> +fsl,mpc5200-fec nodes
> +---------------------
> +The FEC node can specify one of the following properties to configure
> +the MII link:
> +- fsl,7-wire-mode - An empty property that specifies the link uses 7-wire
> +                    mode instead of MII
> +- current-speed   - Specifies that the MII should be configured for a fixed
> +                    speed.  This property should contain two cells.  The
> +                    first cell specifies the speed in Mbps and the second
> +                    should be '0' for half duplex and '1' for full duplex
> +- phy-handle      - Contains a phandle to an Ethernet PHY.
> +
> +Interrupt controller (fsl,mpc5200-pic) node
> +-------------------------------------------
> +The mpc5200 pic binding splits hardware IRQ numbers into two levels.  The
> +split reflects the layout of the PIC hardware itself, which groups
> +interrupts into one of three groups; CRIT, MAIN or PERP.  Also, the
> +Bestcomm dma engine has it's own set of interrupt sources which are
> +cascaded off of peripheral interrupt 0, which the driver interprets as a
> +fourth group, SDMA.
> +
> +The interrupts property for device nodes using the mpc5200 pic consists
> +of three cells; <L1 L2 level>
> +
> +    L1 := [CRIT=0, MAIN=1, PERP=2, SDMA=3]
> +    L2 := interrupt number; directly mapped from the value in the
> +          "ICTL PerStat, MainStat, CritStat Encoded Register"
> +    level := [LEVEL_HIGH=0, EDGE_RISING=1, EDGE_FALLING=2, LEVEL_LOW=3]
> +
> +For external IRQs, use the following interrupt property values (how to
> +specify external interrupts is a frequently asked question):
> +External interrupts:
> +	external irq0:	interrupts = <0 0 n>;
> +	external irq1:	interrupts = <1 1 n>;
> +	external irq2:	interrupts = <1 2 n>;
> +	external irq3:	interrupts = <1 3 n>;
> +'n' is sense (0: level high, 1: edge rising, 2: edge falling 3: level low)
> +
> diff --git a/Documentation/powerpc/mpc52xx-device-tree-bindings.txt b/Documentation/powerpc/mpc52xx-device-tree-bindings.txt
> deleted file mode 100644
> index 6f12f1c..0000000
> --- a/Documentation/powerpc/mpc52xx-device-tree-bindings.txt
> +++ /dev/null
> @@ -1,277 +0,0 @@
> -MPC5200 Device Tree Bindings
> -----------------------------
> -
> -(c) 2006-2007 Secret Lab Technologies Ltd
> -Grant Likely <grant.likely at secretlab.ca>
> -
> -********** DRAFT ***********
> -* WARNING: Do not depend on the stability of these bindings just yet.
> -* The MPC5200 device tree conventions are still in flux
> -* Keep an eye on the linuxppc-dev mailing list for more details
> -********** DRAFT ***********
> -
> -I - Introduction
> -================
> -Boards supported by the arch/powerpc architecture require device tree be
> -passed by the boot loader to the kernel at boot time.  The device tree
> -describes what devices are present on the board and how they are
> -connected.  The device tree can either be passed as a binary blob (as
> -described in Documentation/powerpc/booting-without-of.txt), or passed
> -by Open Firmware (IEEE 1275) compatible firmware using an OF compatible
> -client interface API.
> -
> -This document specifies the requirements on the device-tree for mpc5200
> -based boards.  These requirements are above and beyond the details
> -specified in either the Open Firmware spec or booting-without-of.txt
> -
> -All new mpc5200-based boards are expected to match this document.  In
> -cases where this document is not sufficient to support a new board port,
> -this document should be updated as part of adding the new board support.
> -
> -II - Philosophy
> -===============
> -The core of this document is naming convention.  The whole point of
> -defining this convention is to reduce or eliminate the number of
> -special cases required to support a 5200 board.  If all 5200 boards
> -follow the same convention, then generic 5200 support code will work
> -rather than coding special cases for each new board.
> -
> -This section tries to capture the thought process behind why the naming
> -convention is what it is.
> -
> -1.  names
> ----------
> -There is strong convention/requirements already established for children
> -of the root node.  'cpus' describes the processor cores, 'memory'
> -describes memory, and 'chosen' provides boot configuration.  Other nodes
> -are added to describe devices attached to the processor local bus.
> -
> -Following convention already established with other system-on-chip
> -processors, 5200 device trees should use the name 'soc5200' for the
> -parent node of on chip devices, and the root node should be its parent.
> -
> -Child nodes are typically named after the configured function.  ie.
> -the FEC node is named 'ethernet', and a PSC in uart mode is named 'serial'.
> -
> -2. device_type property
> ------------------------
> -similar to the node name convention above; the device_type reflects the
> -configured function of a device.  ie. 'serial' for a uart and 'spi' for
> -an spi controller.  However, while node names *should* reflect the
> -configured function, device_type *must* match the configured function
> -exactly.
> -
> -3. compatible property
> -----------------------
> -Since device_type isn't enough to match devices to drivers, there also
> -needs to be a naming convention for the compatible property.  Compatible
> -is an list of device descriptions sorted from specific to generic.  For
> -the mpc5200, the required format for each compatible value is
> -<chip>-<device>[-<mode>].  The OS should be able to match a device driver
> -to the device based solely on the compatible value.  If two drivers
> -match on the compatible list; the 'most compatible' driver should be
> -selected.
> -
> -The split between the MPC5200 and the MPC5200B leaves a bit of a
> -conundrum.  How should the compatible property be set up to provide
> -maximum compatibility information; but still accurately describe the
> -chip?  For the MPC5200; the answer is easy.  Most of the SoC devices
> -originally appeared on the MPC5200.  Since they didn't exist anywhere
> -else; the 5200 compatible properties will contain only one item;
> -"mpc5200-<device>".
> -
> -The 5200B is almost the same as the 5200, but not quite.  It fixes
> -silicon bugs and it adds a small number of enhancements.  Most of the
> -devices either provide exactly the same interface as on the 5200.  A few
> -devices have extra functions but still have a backwards compatible mode.
> -To express this information as completely as possible, 5200B device trees
> -should have two items in the compatible list;
> -"mpc5200b-<device>\0mpc5200-<device>".  It is *strongly* recommended
> -that 5200B device trees follow this convention (instead of only listing
> -the base mpc5200 item).
> -
> -If another chip appear on the market with one of the mpc5200 SoC
> -devices, then the compatible list should include mpc5200-<device>.
> -
> -ie. ethernet on mpc5200: compatible = "mpc5200-ethernet"
> -    ethernet on mpc5200b: compatible = "mpc5200b-ethernet\0mpc5200-ethernet"
> -
> -Modal devices, like PSCs, also append the configured function to the
> -end of the compatible field.  ie. A PSC in i2s mode would specify
> -"mpc5200-psc-i2s", not "mpc5200-i2s".  This convention is chosen to
> -avoid naming conflicts with non-psc devices providing the same
> -function.  For example, "mpc5200-spi" and "mpc5200-psc-spi" describe
> -the mpc5200 simple spi device and a PSC spi mode respectively.
> -
> -If the soc device is more generic and present on other SOCs, the
> -compatible property can specify the more generic device type also.
> -
> -ie. mscan: compatible = "mpc5200-mscan\0fsl,mscan";
> -
> -At the time of writing, exact chip may be either 'mpc5200' or
> -'mpc5200b'.
> -
> -Device drivers should always try to match as generically as possible.
> -
> -III - Structure
> -===============
> -The device tree for an mpc5200 board follows the structure defined in
> -booting-without-of.txt with the following additional notes:
> -
> -0) the root node
> -----------------
> -Typical root description node; see booting-without-of
> -
> -1) The cpus node
> -----------------
> -The cpus node follows the basic layout described in booting-without-of.
> -The bus-frequency property holds the XLB bus frequency
> -The clock-frequency property holds the core frequency
> -
> -2) The memory node
> -------------------
> -Typical memory description node; see booting-without-of.
> -
> -3) The soc5200 node
> --------------------
> -This node describes the on chip SOC peripherals.  Every mpc5200 based
> -board will have this node, and as such there is a common naming
> -convention for SOC devices.
> -
> -Required properties:
> -name			type		description
> -----			----		-----------
> -device_type		string		must be "soc"
> -ranges			int		should be <0 baseaddr baseaddr+10000>
> -reg			int		must be <baseaddr 10000>
> -compatible		string		mpc5200: "mpc5200-soc"
> -					mpc5200b: "mpc5200b-soc\0mpc5200-soc"
> -system-frequency	int		Fsystem frequency; source of all
> -					other clocks.
> -bus-frequency		int		IPB bus frequency in HZ.  Clock rate
> -					used by most of the soc devices.
> -#interrupt-cells	int		must be <3>.
> -
> -Recommended properties:
> -name			type		description
> -----			----		-----------
> -model			string		Exact model of the chip;
> -					ie: model="fsl,mpc5200"
> -revision		string		Silicon revision of chip
> -					ie: revision="M08A"
> -
> -The 'model' and 'revision' properties are *strongly* recommended.  Having
> -them presence acts as a bit of a safety net for working around as yet
> -undiscovered bugs on one version of silicon.  For example, device drivers
> -can use the model and revision properties to decide if a bug fix should
> -be turned on.
> -
> -4) soc5200 child nodes
> -----------------------
> -Any on chip SOC devices available to Linux must appear as soc5200 child nodes.
> -
> -Note: The tables below show the value for the mpc5200.  A mpc5200b device
> -tree should use the "mpc5200b-<device>\0mpc5200-<device> form.
> -
> -Required soc5200 child nodes:
> -name		device_type		compatible	Description
> -----		-----------		----------	-----------
> -cdm@<addr>	cdm			mpc5200-cmd	Clock Distribution
> -pic@<addr>	interrupt-controller	mpc5200-pic	need an interrupt
> -							controller to boot
> -bestcomm@<addr>	dma-controller		mpc5200-bestcomm 5200 pic also requires
> -							 the bestcomm device
> -
> -Recommended soc5200 child nodes; populate as needed for your board
> -name		device_type	compatible	  Description
> -----		-----------	----------	  -----------
> -gpt@<addr>	gpt		fsl,mpc5200-gpt	  General purpose timers
> -gpt@<addr>	gpt		fsl,mpc5200-gpt-gpio	General purpose
> -							timers in GPIO mode
> -gpio@<addr>			fsl,mpc5200-gpio	MPC5200 simple gpio
> -							controller
> -gpio@<addr>			fsl,mpc5200-gpio-wkup	MPC5200 wakeup gpio
> -							controller
> -rtc@<addr>	rtc		mpc5200-rtc	  Real time clock
> -mscan@<addr>	mscan		mpc5200-mscan	  CAN bus controller
> -pci@<addr>	pci		mpc5200-pci	  PCI bridge
> -serial@<addr>	serial		mpc5200-psc-uart  PSC in serial mode
> -i2s@<addr>	sound		mpc5200-psc-i2s	  PSC in i2s mode
> -ac97@<addr>	sound		mpc5200-psc-ac97  PSC in ac97 mode
> -spi@<addr>	spi		mpc5200-psc-spi	  PSC in spi mode
> -irda@<addr>	irda		mpc5200-psc-irda  PSC in IrDA mode
> -spi@<addr>	spi		mpc5200-spi	  MPC5200 spi device
> -ethernet@<addr>	network		mpc5200-fec	  MPC5200 ethernet device
> -ata@<addr>	ata		mpc5200-ata	  IDE ATA interface
> -i2c@<addr>	i2c		mpc5200-i2c	  I2C controller
> -usb@<addr>	usb-ohci-be	mpc5200-ohci,ohci-be	USB controller
> -xlb@<addr>	xlb		mpc5200-xlb	  XLB arbitrator
> -
> -Important child node properties
> -name		type		description
> -----		----		-----------
> -cell-index	int		When multiple devices are present, is the
> -				index of the device in the hardware (ie. There
> -				are 6 PSC on the 5200 numbered PSC1 to PSC6)
> -				    PSC1 has 'cell-index = <0>'
> -				    PSC4 has 'cell-index = <3>'
> -
> -5) General Purpose Timer nodes (child of soc5200 node)
> -On the mpc5200 and 5200b, GPT0 has a watchdog timer function.  If the board
> -design supports the internal wdt, then the device node for GPT0 should
> -include the empty property 'fsl,has-wdt'.
> -
> -6) PSC nodes (child of soc5200 node)
> -PSC nodes can define the optional 'port-number' property to force assignment
> -order of serial ports.  For example, PSC5 might be physically connected to
> -the port labeled 'COM1' and PSC1 wired to 'COM1'.  In this case, PSC5 would
> -have a "port-number = <0>" property, and PSC1 would have "port-number = <1>".
> -
> -PSC in i2s mode:  The mpc5200 and mpc5200b PSCs are not compatible when in
> -i2s mode.  An 'mpc5200b-psc-i2s' node cannot include 'mpc5200-psc-i2s' in the
> -compatible field.
> -
> -7) GPIO controller nodes
> -Each GPIO controller node should have the empty property gpio-controller and
> -#gpio-cells set to 2. First cell is the GPIO number which is interpreted
> -according to the bit numbers in the GPIO control registers. The second cell
> -is for flags which is currently unsused.
> -
> -8) FEC nodes
> -The FEC node can specify one of the following properties to configure
> -the MII link:
> -"fsl,7-wire-mode" - An empty property that specifies the link uses 7-wire
> -                    mode instead of MII
> -"current-speed"   - Specifies that the MII should be configured for a fixed
> -                    speed.  This property should contain two cells.  The
> -                    first cell specifies the speed in Mbps and the second
> -                    should be '0' for half duplex and '1' for full duplex
> -"phy-handle"      - Contains a phandle to an Ethernet PHY.
> -
> -IV - Extra Notes
> -================
> -
> -1. Interrupt mapping
> ---------------------
> -The mpc5200 pic driver splits hardware IRQ numbers into two levels.  The
> -split reflects the layout of the PIC hardware itself, which groups
> -interrupts into one of three groups; CRIT, MAIN or PERP.  Also, the
> -Bestcomm dma engine has it's own set of interrupt sources which are
> -cascaded off of peripheral interrupt 0, which the driver interprets as a
> -fourth group, SDMA.
> -
> -The interrupts property for device nodes using the mpc5200 pic consists
> -of three cells; <L1 L2 level>
> -
> -    L1 := [CRIT=0, MAIN=1, PERP=2, SDMA=3]
> -    L2 := interrupt number; directly mapped from the value in the
> -          "ICTL PerStat, MainStat, CritStat Encoded Register"
> -    level := [LEVEL_HIGH=0, EDGE_RISING=1, EDGE_FALLING=2, LEVEL_LOW=3]
> -
> -2. Shared registers
> --------------------
> -Some SoC devices share registers between them.  ie. the i2c devices use
> -a single clock control register, and almost all device are affected by
> -the port_config register.  Devices which need to manipulate shared regs
> -should look to the parent SoC node.  The soc node is responsible
> -for arbitrating all shared register access.
> 

Regards,

   Wolfram
Grant Likely - Jan. 26, 2009, 1:46 a.m.
On Sun, Jan 25, 2009 at 12:48 PM, Wolfram Sang <w.sang@pengutronix.de> wrote:
> On Wed, Jan 21, 2009 at 01:55:07PM -0700, Grant Likely wrote:
>> +system-frequency     Fsystem frequency; source of all
>
> Fsystem? Typo?

Not really, that's the name of the clock in the MP5200 user guide.
I'll clarify what I've written here though.

> The unit would be nice here, too, I think.

Unit?  Do you mean stating that it is in Hz?

>> +cdm@<addr>                   fsl,mpc5200-cmd         Clock Distribution
>
>                                             ^^ cdm!

>> +is for flags which is currently unsused.
>
> Typo: should be "unused".

Good catches, thanks.

g.
Wolfram Sang - Jan. 26, 2009, 9:26 a.m.
> >> +system-frequency     Fsystem frequency; source of all
> >
> > Fsystem? Typo?
> 
> Not really, that's the name of the clock in the MP5200 user guide.
> I'll clarify what I've written here though.

That will be helpful.

> > The unit would be nice here, too, I think.
> 
> Unit?  Do you mean stating that it is in Hz?

Yes, like in the frequency next to it.

Kind regards,

   Wolfram

PS: The other patches look good to me, too. I just want to test them on
a real phyCORE-tiny this week.
Grant Likely - Jan. 27, 2009, 4:25 p.m.
On Mon, Jan 26, 2009 at 2:26 AM, Wolfram Sang <w.sang@pengutronix.de> wrote:
>
>> >> +system-frequency     Fsystem frequency; source of all
>> >
>> > Fsystem? Typo?
>>
>> Not really, that's the name of the clock in the MP5200 user guide.
>> I'll clarify what I've written here though.
>
> That will be helpful.
>
>> > The unit would be nice here, too, I think.
>>
>> Unit?  Do you mean stating that it is in Hz?
>
> Yes, like in the frequency next to it.
>
> Kind regards,
>
>   Wolfram
>
> PS: The other patches look good to me, too. I just want to test them on
> a real phyCORE-tiny this week.

Thanks,

I want to get these queued up into -next ASAP, so let me know when
you've had a chance to try them.

g.
Matt Sealey - Jan. 27, 2009, 6 p.m.
On Wed, Jan 21, 2009 at 2:55 PM, Grant Likely <grant.likely@secretlab.ca> wrote:
> From: Grant Likely <grant.likely@secretlab.ca>
>
> This patch updates the mpc5200 binding documentation to match
> actual usage conventions, to remove incorrect information, and
> to remove topics which are more thoroughly described elsewhere.
>
> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
> CC: devtree-discuss@ozlabs.org
> CC: Wolfram Sang <w.sang@pengutronix.de>
> ---
> +It is *strongly* recommended that 5200B device trees follow this convention
> +(instead of only listing the base mpc5200 item).
> +
> +ie. ethernet on mpc5200: compatible = "fsl,mpc5200-ethernet";
> +    ethernet on mpc5200b: compatible = "fsl,mpc5200b-ethernet",
> +                                       "fsl,mpc5200-ethernet";

snip

> +ethernet@<addr>        fsl,mpc5200-fec          MPC5200 ethernet device

snip

> +fsl,mpc5200-fec nodes
> +---------------------
> +The FEC node can specify one of the following properties to configure
> +the MII link:


Is it fec or ethernet? Obviously the first one is an example only but
it should least reflect real life..
Grant Likely - Jan. 27, 2009, 6:06 p.m.
On Tue, Jan 27, 2009 at 11:00 AM, Matt Sealey <matt@genesi-usa.com> wrote:
> On Wed, Jan 21, 2009 at 2:55 PM, Grant Likely <grant.likely@secretlab.ca> wrote:
>> From: Grant Likely <grant.likely@secretlab.ca>
>>
>> This patch updates the mpc5200 binding documentation to match
>> actual usage conventions, to remove incorrect information, and
>> to remove topics which are more thoroughly described elsewhere.
>>
>> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
>> CC: devtree-discuss@ozlabs.org
>> CC: Wolfram Sang <w.sang@pengutronix.de>
>> ---
>> +It is *strongly* recommended that 5200B device trees follow this convention
>> +(instead of only listing the base mpc5200 item).
>> +
>> +ie. ethernet on mpc5200: compatible = "fsl,mpc5200-ethernet";
>> +    ethernet on mpc5200b: compatible = "fsl,mpc5200b-ethernet",
>> +                                       "fsl,mpc5200-ethernet";
>
> snip
>
>> +ethernet@<addr>        fsl,mpc5200-fec          MPC5200 ethernet device
>
> snip
>
>> +fsl,mpc5200-fec nodes
>> +---------------------
>> +The FEC node can specify one of the following properties to configure
>> +the MII link:
>
>
> Is it fec or ethernet? Obviously the first one is an example only but
> it should least reflect real life..

Good catch.  It should be -fec.  Fixed.

g.
Wolfram Sang - Jan. 29, 2009, 9:09 p.m.
Hello Grant,

On Wed, Jan 21, 2009 at 01:55:07PM -0700, Grant Likely wrote:
> From: Grant Likely <grant.likely@secretlab.ca>
> 
> This patch updates the mpc5200 binding documentation to match
> actual usage conventions, to remove incorrect information, and
> to remove topics which are more thoroughly described elsewhere.
> 
> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
> CC: devtree-discuss@ozlabs.org
> CC: Wolfram Sang <w.sang@pengutronix.de>

Can you please send the updated version so I could add an reviewed-by?

Regards,

   Wolfram

Patch

diff --git a/Documentation/powerpc/dts-bindings/fsl/mpc5200.txt b/Documentation/powerpc/dts-bindings/fsl/mpc5200.txt
new file mode 100644
index 0000000..1eddda7
--- /dev/null
+++ b/Documentation/powerpc/dts-bindings/fsl/mpc5200.txt
@@ -0,0 +1,181 @@ 
+MPC5200 Device Tree Bindings
+----------------------------
+
+(c) 2006-2009 Secret Lab Technologies Ltd
+Grant Likely <grant.likely@secretlab.ca>
+
+Naming conventions
+------------------
+For mpc5200 on-chip devices, the format for each compatible value is
+<chip>-<device>[-<mode>].  The OS should be able to match a device driver
+to the device based solely on the compatible value.  If two drivers
+match on the compatible list; the 'most compatible' driver should be
+selected.
+
+The split between the MPC5200 and the MPC5200B leaves a bit of a
+conundrum.  How should the compatible property be set up to provide
+maximum compatibility information; but still accurately describe the
+chip?  For the MPC5200; the answer is easy.  Most of the SoC devices
+originally appeared on the MPC5200.  Since they didn't exist anywhere
+else; the 5200 compatible properties will contain only one item;
+"fsl,mpc5200-<device>".
+
+The 5200B is almost the same as the 5200, but not quite.  It fixes
+silicon bugs and it adds a small number of enhancements.  Most of the
+devices either provide exactly the same interface as on the 5200.  A few
+devices have extra functions but still have a backwards compatible mode.
+To express this information as completely as possible, 5200B device trees
+should have two items in the compatible list:
+	compatible = "fsl,mpc5200b-<device>","fsl,mpc5200-<device>";
+
+It is *strongly* recommended that 5200B device trees follow this convention
+(instead of only listing the base mpc5200 item).
+
+ie. ethernet on mpc5200: compatible = "fsl,mpc5200-ethernet";
+    ethernet on mpc5200b: compatible = "fsl,mpc5200b-ethernet",
+                                       "fsl,mpc5200-ethernet";
+
+Modal devices, like PSCs, also append the configured function to the
+end of the compatible field.  ie. A PSC in i2s mode would specify
+"fsl,mpc5200-psc-i2s", not "fsl,mpc5200-i2s".  This convention is chosen to
+avoid naming conflicts with non-psc devices providing the same
+function.  For example, "fsl,mpc5200-spi" and "fsl,mpc5200-psc-spi" describe
+the mpc5200 simple spi device and a PSC spi mode respectively.
+
+At the time of writing, exact chip may be either 'fsl,mpc5200' or
+'fsl,mpc5200b'.
+
+The soc node
+------------
+This node describes the on chip SOC peripherals.  Every mpc5200 based
+board will have this node, and as such there is a common naming
+convention for SOC devices.
+
+Required properties:
+name			description
+----			-----------
+ranges			Memory range of the internal memory mapped registers.
+			Should be <0 [baseaddr] 0xc000>
+reg			Should be <[baseaddr] 0x100>
+compatible		mpc5200: "fsl,mpc5200-immr"
+			mpc5200b: "fsl,mpc5200b-immr"
+system-frequency	Fsystem frequency; source of all
+			other clocks.
+bus-frequency		IPB bus frequency in HZ.  Clock rate
+			used by most of the soc devices.
+
+soc child nodes
+---------------
+Any on chip SOC devices available to Linux must appear as soc5200 child nodes.
+
+Note: The tables below show the value for the mpc5200.  A mpc5200b device
+tree should use the "fsl,mpc5200b-<device>","fsl,mpc5200-<device>" form.
+
+Required soc5200 child nodes:
+name				compatible		Description
+----				----------		-----------
+cdm@<addr>			fsl,mpc5200-cmd		Clock Distribution
+interrupt-controller@<addr>	fsl,mpc5200-pic		need an interrupt
+							controller to boot
+bestcomm@<addr>			fsl,mpc5200-bestcomm	Bestcomm DMA controller
+
+Recommended soc5200 child nodes; populate as needed for your board
+name		compatible		Description
+----		----------		-----------
+timer@<addr>	fsl,mpc5200-gpt		 General purpose timers
+gpio@<addr>	fsl,mpc5200-gpio	 MPC5200 simple gpio controller
+gpio@<addr>	fsl,mpc5200-gpio-wkup	 MPC5200 wakeup gpio controller
+rtc@<addr>	fsl,mpc5200-rtc		 Real time clock
+mscan@<addr>	fsl,mpc5200-mscan	 CAN bus controller
+pci@<addr>	fsl,mpc5200-pci		 PCI bridge
+serial@<addr>	fsl,mpc5200-psc-uart	 PSC in serial mode
+i2s@<addr>	fsl,mpc5200-psc-i2s	 PSC in i2s mode
+ac97@<addr>	fsl,mpc5200-psc-ac97	 PSC in ac97 mode
+spi@<addr>	fsl,mpc5200-psc-spi	 PSC in spi mode
+irda@<addr>	fsl,mpc5200-psc-irda	 PSC in IrDA mode
+spi@<addr>	fsl,mpc5200-spi		 MPC5200 spi device
+ethernet@<addr>	fsl,mpc5200-fec		 MPC5200 ethernet device
+ata@<addr>	fsl,mpc5200-ata		 IDE ATA interface
+i2c@<addr>	fsl,mpc5200-i2c		 I2C controller
+usb@<addr>	fsl,mpc5200-ohci,ohci-be USB controller
+xlb@<addr>	fsl,mpc5200-xlb		 XLB arbitrator
+
+fsl,mpc5200-gpt nodes
+---------------------
+On the mpc5200 and 5200b, GPT0 has a watchdog timer function.  If the board
+design supports the internal wdt, then the device node for GPT0 should
+include the empty property 'fsl,has-wdt'.
+
+An mpc5200-gpt can be used as a single line GPIO controller.  To do so,
+add the following properties to the gpt node:
+	gpio-controller;
+	#gpio-cells = <2>;
+When referencing the GPIO line from another node, the first cell must always
+be zero and the second cell represents the gpio flags and described in the
+gpio device tree binding.
+
+An mpc5200-gpt can be used as a single line edge sensitive interrupt
+controller.  To do so, add the following properties to the gpt node:
+	interrupt-controller;
+	#interrupt-cells = <1>;
+When referencing the IRQ line from another node, the cell represents the
+sense mode; 1 for edge rising, 2 for edge falling.
+
+fsl,mpc5200-psc nodes
+---------------------
+The PSCs should include a cell-index which is the index of the PSC in
+hardware.  cell-index is used to determine which shared SoC registers to
+use when setting up PSC clocking.  cell-index number starts at '0'.  ie:
+	PSC1 has 'cell-index = <0>'
+	PSC4 has 'cell-index = <3>'
+
+PSC in i2s mode:  The mpc5200 and mpc5200b PSCs are not compatible when in
+i2s mode.  An 'mpc5200b-psc-i2s' node cannot include 'mpc5200-psc-i2s' in the
+compatible field.
+
+
+fsl,mpc5200-gpio and fsl,mpc5200-gpio-wkup nodes
+------------------------------------------------
+Each GPIO controller node should have the empty property gpio-controller and
+#gpio-cells set to 2. First cell is the GPIO number which is interpreted
+according to the bit numbers in the GPIO control registers. The second cell
+is for flags which is currently unsused.
+
+fsl,mpc5200-fec nodes
+---------------------
+The FEC node can specify one of the following properties to configure
+the MII link:
+- fsl,7-wire-mode - An empty property that specifies the link uses 7-wire
+                    mode instead of MII
+- current-speed   - Specifies that the MII should be configured for a fixed
+                    speed.  This property should contain two cells.  The
+                    first cell specifies the speed in Mbps and the second
+                    should be '0' for half duplex and '1' for full duplex
+- phy-handle      - Contains a phandle to an Ethernet PHY.
+
+Interrupt controller (fsl,mpc5200-pic) node
+-------------------------------------------
+The mpc5200 pic binding splits hardware IRQ numbers into two levels.  The
+split reflects the layout of the PIC hardware itself, which groups
+interrupts into one of three groups; CRIT, MAIN or PERP.  Also, the
+Bestcomm dma engine has it's own set of interrupt sources which are
+cascaded off of peripheral interrupt 0, which the driver interprets as a
+fourth group, SDMA.
+
+The interrupts property for device nodes using the mpc5200 pic consists
+of three cells; <L1 L2 level>
+
+    L1 := [CRIT=0, MAIN=1, PERP=2, SDMA=3]
+    L2 := interrupt number; directly mapped from the value in the
+          "ICTL PerStat, MainStat, CritStat Encoded Register"
+    level := [LEVEL_HIGH=0, EDGE_RISING=1, EDGE_FALLING=2, LEVEL_LOW=3]
+
+For external IRQs, use the following interrupt property values (how to
+specify external interrupts is a frequently asked question):
+External interrupts:
+	external irq0:	interrupts = <0 0 n>;
+	external irq1:	interrupts = <1 1 n>;
+	external irq2:	interrupts = <1 2 n>;
+	external irq3:	interrupts = <1 3 n>;
+'n' is sense (0: level high, 1: edge rising, 2: edge falling 3: level low)
+
diff --git a/Documentation/powerpc/mpc52xx-device-tree-bindings.txt b/Documentation/powerpc/mpc52xx-device-tree-bindings.txt
deleted file mode 100644
index 6f12f1c..0000000
--- a/Documentation/powerpc/mpc52xx-device-tree-bindings.txt
+++ /dev/null
@@ -1,277 +0,0 @@ 
-MPC5200 Device Tree Bindings
-----------------------------
-
-(c) 2006-2007 Secret Lab Technologies Ltd
-Grant Likely <grant.likely at secretlab.ca>
-
-********** DRAFT ***********
-* WARNING: Do not depend on the stability of these bindings just yet.
-* The MPC5200 device tree conventions are still in flux
-* Keep an eye on the linuxppc-dev mailing list for more details
-********** DRAFT ***********
-
-I - Introduction
-================
-Boards supported by the arch/powerpc architecture require device tree be
-passed by the boot loader to the kernel at boot time.  The device tree
-describes what devices are present on the board and how they are
-connected.  The device tree can either be passed as a binary blob (as
-described in Documentation/powerpc/booting-without-of.txt), or passed
-by Open Firmware (IEEE 1275) compatible firmware using an OF compatible
-client interface API.
-
-This document specifies the requirements on the device-tree for mpc5200
-based boards.  These requirements are above and beyond the details
-specified in either the Open Firmware spec or booting-without-of.txt
-
-All new mpc5200-based boards are expected to match this document.  In
-cases where this document is not sufficient to support a new board port,
-this document should be updated as part of adding the new board support.
-
-II - Philosophy
-===============
-The core of this document is naming convention.  The whole point of
-defining this convention is to reduce or eliminate the number of
-special cases required to support a 5200 board.  If all 5200 boards
-follow the same convention, then generic 5200 support code will work
-rather than coding special cases for each new board.
-
-This section tries to capture the thought process behind why the naming
-convention is what it is.
-
-1.  names
----------
-There is strong convention/requirements already established for children
-of the root node.  'cpus' describes the processor cores, 'memory'
-describes memory, and 'chosen' provides boot configuration.  Other nodes
-are added to describe devices attached to the processor local bus.
-
-Following convention already established with other system-on-chip
-processors, 5200 device trees should use the name 'soc5200' for the
-parent node of on chip devices, and the root node should be its parent.
-
-Child nodes are typically named after the configured function.  ie.
-the FEC node is named 'ethernet', and a PSC in uart mode is named 'serial'.
-
-2. device_type property
------------------------
-similar to the node name convention above; the device_type reflects the
-configured function of a device.  ie. 'serial' for a uart and 'spi' for
-an spi controller.  However, while node names *should* reflect the
-configured function, device_type *must* match the configured function
-exactly.
-
-3. compatible property
-----------------------
-Since device_type isn't enough to match devices to drivers, there also
-needs to be a naming convention for the compatible property.  Compatible
-is an list of device descriptions sorted from specific to generic.  For
-the mpc5200, the required format for each compatible value is
-<chip>-<device>[-<mode>].  The OS should be able to match a device driver
-to the device based solely on the compatible value.  If two drivers
-match on the compatible list; the 'most compatible' driver should be
-selected.
-
-The split between the MPC5200 and the MPC5200B leaves a bit of a
-conundrum.  How should the compatible property be set up to provide
-maximum compatibility information; but still accurately describe the
-chip?  For the MPC5200; the answer is easy.  Most of the SoC devices
-originally appeared on the MPC5200.  Since they didn't exist anywhere
-else; the 5200 compatible properties will contain only one item;
-"mpc5200-<device>".
-
-The 5200B is almost the same as the 5200, but not quite.  It fixes
-silicon bugs and it adds a small number of enhancements.  Most of the
-devices either provide exactly the same interface as on the 5200.  A few
-devices have extra functions but still have a backwards compatible mode.
-To express this information as completely as possible, 5200B device trees
-should have two items in the compatible list;
-"mpc5200b-<device>\0mpc5200-<device>".  It is *strongly* recommended
-that 5200B device trees follow this convention (instead of only listing
-the base mpc5200 item).
-
-If another chip appear on the market with one of the mpc5200 SoC
-devices, then the compatible list should include mpc5200-<device>.
-
-ie. ethernet on mpc5200: compatible = "mpc5200-ethernet"
-    ethernet on mpc5200b: compatible = "mpc5200b-ethernet\0mpc5200-ethernet"
-
-Modal devices, like PSCs, also append the configured function to the
-end of the compatible field.  ie. A PSC in i2s mode would specify
-"mpc5200-psc-i2s", not "mpc5200-i2s".  This convention is chosen to
-avoid naming conflicts with non-psc devices providing the same
-function.  For example, "mpc5200-spi" and "mpc5200-psc-spi" describe
-the mpc5200 simple spi device and a PSC spi mode respectively.
-
-If the soc device is more generic and present on other SOCs, the
-compatible property can specify the more generic device type also.
-
-ie. mscan: compatible = "mpc5200-mscan\0fsl,mscan";
-
-At the time of writing, exact chip may be either 'mpc5200' or
-'mpc5200b'.
-
-Device drivers should always try to match as generically as possible.
-
-III - Structure
-===============
-The device tree for an mpc5200 board follows the structure defined in
-booting-without-of.txt with the following additional notes:
-
-0) the root node
-----------------
-Typical root description node; see booting-without-of
-
-1) The cpus node
-----------------
-The cpus node follows the basic layout described in booting-without-of.
-The bus-frequency property holds the XLB bus frequency
-The clock-frequency property holds the core frequency
-
-2) The memory node
-------------------
-Typical memory description node; see booting-without-of.
-
-3) The soc5200 node
--------------------
-This node describes the on chip SOC peripherals.  Every mpc5200 based
-board will have this node, and as such there is a common naming
-convention for SOC devices.
-
-Required properties:
-name			type		description
-----			----		-----------
-device_type		string		must be "soc"
-ranges			int		should be <0 baseaddr baseaddr+10000>
-reg			int		must be <baseaddr 10000>
-compatible		string		mpc5200: "mpc5200-soc"
-					mpc5200b: "mpc5200b-soc\0mpc5200-soc"
-system-frequency	int		Fsystem frequency; source of all
-					other clocks.
-bus-frequency		int		IPB bus frequency in HZ.  Clock rate
-					used by most of the soc devices.
-#interrupt-cells	int		must be <3>.
-
-Recommended properties:
-name			type		description
-----			----		-----------
-model			string		Exact model of the chip;
-					ie: model="fsl,mpc5200"
-revision		string		Silicon revision of chip
-					ie: revision="M08A"
-
-The 'model' and 'revision' properties are *strongly* recommended.  Having
-them presence acts as a bit of a safety net for working around as yet
-undiscovered bugs on one version of silicon.  For example, device drivers
-can use the model and revision properties to decide if a bug fix should
-be turned on.
-
-4) soc5200 child nodes
-----------------------
-Any on chip SOC devices available to Linux must appear as soc5200 child nodes.
-
-Note: The tables below show the value for the mpc5200.  A mpc5200b device
-tree should use the "mpc5200b-<device>\0mpc5200-<device> form.
-
-Required soc5200 child nodes:
-name		device_type		compatible	Description
-----		-----------		----------	-----------
-cdm@<addr>	cdm			mpc5200-cmd	Clock Distribution
-pic@<addr>	interrupt-controller	mpc5200-pic	need an interrupt
-							controller to boot
-bestcomm@<addr>	dma-controller		mpc5200-bestcomm 5200 pic also requires
-							 the bestcomm device
-
-Recommended soc5200 child nodes; populate as needed for your board
-name		device_type	compatible	  Description
-----		-----------	----------	  -----------
-gpt@<addr>	gpt		fsl,mpc5200-gpt	  General purpose timers
-gpt@<addr>	gpt		fsl,mpc5200-gpt-gpio	General purpose
-							timers in GPIO mode
-gpio@<addr>			fsl,mpc5200-gpio	MPC5200 simple gpio
-							controller
-gpio@<addr>			fsl,mpc5200-gpio-wkup	MPC5200 wakeup gpio
-							controller
-rtc@<addr>	rtc		mpc5200-rtc	  Real time clock
-mscan@<addr>	mscan		mpc5200-mscan	  CAN bus controller
-pci@<addr>	pci		mpc5200-pci	  PCI bridge
-serial@<addr>	serial		mpc5200-psc-uart  PSC in serial mode
-i2s@<addr>	sound		mpc5200-psc-i2s	  PSC in i2s mode
-ac97@<addr>	sound		mpc5200-psc-ac97  PSC in ac97 mode
-spi@<addr>	spi		mpc5200-psc-spi	  PSC in spi mode
-irda@<addr>	irda		mpc5200-psc-irda  PSC in IrDA mode
-spi@<addr>	spi		mpc5200-spi	  MPC5200 spi device
-ethernet@<addr>	network		mpc5200-fec	  MPC5200 ethernet device
-ata@<addr>	ata		mpc5200-ata	  IDE ATA interface
-i2c@<addr>	i2c		mpc5200-i2c	  I2C controller
-usb@<addr>	usb-ohci-be	mpc5200-ohci,ohci-be	USB controller
-xlb@<addr>	xlb		mpc5200-xlb	  XLB arbitrator
-
-Important child node properties
-name		type		description
-----		----		-----------
-cell-index	int		When multiple devices are present, is the
-				index of the device in the hardware (ie. There
-				are 6 PSC on the 5200 numbered PSC1 to PSC6)
-				    PSC1 has 'cell-index = <0>'
-				    PSC4 has 'cell-index = <3>'
-
-5) General Purpose Timer nodes (child of soc5200 node)
-On the mpc5200 and 5200b, GPT0 has a watchdog timer function.  If the board
-design supports the internal wdt, then the device node for GPT0 should
-include the empty property 'fsl,has-wdt'.
-
-6) PSC nodes (child of soc5200 node)
-PSC nodes can define the optional 'port-number' property to force assignment
-order of serial ports.  For example, PSC5 might be physically connected to
-the port labeled 'COM1' and PSC1 wired to 'COM1'.  In this case, PSC5 would
-have a "port-number = <0>" property, and PSC1 would have "port-number = <1>".
-
-PSC in i2s mode:  The mpc5200 and mpc5200b PSCs are not compatible when in
-i2s mode.  An 'mpc5200b-psc-i2s' node cannot include 'mpc5200-psc-i2s' in the
-compatible field.
-
-7) GPIO controller nodes
-Each GPIO controller node should have the empty property gpio-controller and
-#gpio-cells set to 2. First cell is the GPIO number which is interpreted
-according to the bit numbers in the GPIO control registers. The second cell
-is for flags which is currently unsused.
-
-8) FEC nodes
-The FEC node can specify one of the following properties to configure
-the MII link:
-"fsl,7-wire-mode" - An empty property that specifies the link uses 7-wire
-                    mode instead of MII
-"current-speed"   - Specifies that the MII should be configured for a fixed
-                    speed.  This property should contain two cells.  The
-                    first cell specifies the speed in Mbps and the second
-                    should be '0' for half duplex and '1' for full duplex
-"phy-handle"      - Contains a phandle to an Ethernet PHY.
-
-IV - Extra Notes
-================
-
-1. Interrupt mapping
---------------------
-The mpc5200 pic driver splits hardware IRQ numbers into two levels.  The
-split reflects the layout of the PIC hardware itself, which groups
-interrupts into one of three groups; CRIT, MAIN or PERP.  Also, the
-Bestcomm dma engine has it's own set of interrupt sources which are
-cascaded off of peripheral interrupt 0, which the driver interprets as a
-fourth group, SDMA.
-
-The interrupts property for device nodes using the mpc5200 pic consists
-of three cells; <L1 L2 level>
-
-    L1 := [CRIT=0, MAIN=1, PERP=2, SDMA=3]
-    L2 := interrupt number; directly mapped from the value in the
-          "ICTL PerStat, MainStat, CritStat Encoded Register"
-    level := [LEVEL_HIGH=0, EDGE_RISING=1, EDGE_FALLING=2, LEVEL_LOW=3]
-
-2. Shared registers
--------------------
-Some SoC devices share registers between them.  ie. the i2c devices use
-a single clock control register, and almost all device are affected by
-the port_config register.  Devices which need to manipulate shared regs
-should look to the parent SoC node.  The soc node is responsible
-for arbitrating all shared register access.