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Merge branch 'vexpress-clk-soc' of git://git.linaro.org/people/pawelm…
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…oll/linux into next/soc2

From Pawel Moll <pawel.moll@arm.com>:

This reworks the generic support for versatile express, in part
as preparation for the arm64 version of it that can now share
more of the code.

The series is based on top of the clk tree from Mike Turquette.

* 'vexpress-clk-soc' of git://git.linaro.org/people/pawelmoll/linux:
  ARM: vexpress: Remove motherboard dependencies in the DTS files
  ARM: vexpress: Start using new Versatile Express infrastructure
  ARM: vexpress: Add config bus components and clocks to DTs
  mfd: Versatile Express system registers driver
  mfd: Versatile Express config infrastructure

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
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Arnd Bergmann committed Nov 5, 2012
2 parents 8f0d816 + 433683a commit dbe3053
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50 changes: 50 additions & 0 deletions Documentation/devicetree/bindings/arm/vexpress-sysreg.txt
Original file line number Diff line number Diff line change
@@ -0,0 +1,50 @@
ARM Versatile Express system registers
--------------------------------------

This is a system control registers block, providing multiple low level
platform functions like board detection and identification, software
interrupt generation, MMC and NOR Flash control etc.

Required node properties:
- compatible value : = "arm,vexpress,sysreg";
- reg : physical base address and the size of the registers window
- gpio-controller : specifies that the node is a GPIO controller
- #gpio-cells : size of the GPIO specifier, should be 2:
- first cell is the pseudo-GPIO line number:
0 - MMC CARDIN
1 - MMC WPROT
2 - NOR FLASH WPn
- second cell can take standard GPIO flags (currently ignored).

Example:
v2m_sysreg: sysreg@10000000 {
compatible = "arm,vexpress-sysreg";
reg = <0x10000000 0x1000>;
gpio-controller;
#gpio-cells = <2>;
};

This block also can also act a bridge to the platform's configuration
bus via "system control" interface, addressing devices with site number,
position in the board stack, config controller, function and device
numbers - see motherboard's TRM for more details.

The node describing a config device must refer to the sysreg node via
"arm,vexpress,config-bridge" phandle (can be also defined in the node's
parent) and relies on the board topology properties - see main vexpress
node documentation for more details. It must must also define the
following property:
- arm,vexpress-sysreg,func : must contain two cells:
- first cell defines function number (eg. 1 for clock generator,
2 for voltage regulators etc.)
- device number (eg. osc 0, osc 1 etc.)

Example:
mcc {
arm,vexpress,config-bridge = <&v2m_sysreg>;

osc@0 {
compatible = "arm,vexpress-osc";
arm,vexpress-sysreg,func = <1 0>;
};
};
98 changes: 88 additions & 10 deletions Documentation/devicetree/bindings/arm/vexpress.txt
Original file line number Diff line number Diff line change
Expand Up @@ -11,6 +11,10 @@ the motherboard file using a /include/ directive. As the motherboard
can be initialized in one of two different configurations ("memory
maps"), care must be taken to include the correct one.


Root node
---------

Required properties in the root node:
- compatible value:
compatible = "arm,vexpress,<model>", "arm,vexpress";
Expand Down Expand Up @@ -45,6 +49,10 @@ Optional properties in the root node:
- Coretile Express A9x4 (V2P-CA9) HBI-0225:
arm,hbi = <0x225>;


CPU nodes
---------

Top-level standard "cpus" node is required. It must contain a node
with device_type = "cpu" property for every available core, eg.:

Expand All @@ -59,6 +67,52 @@ with device_type = "cpu" property for every available core, eg.:
};
};


Configuration infrastructure
----------------------------

The platform has an elaborated configuration system, consisting of
microcontrollers residing on the mother- and daughterboards known
as Motherboard/Daughterboard Configuration Controller (MCC and DCC).
The controllers are responsible for the platform initialization
(reset generation, flash programming, FPGA bitfiles loading etc.)
but also control clock generators, voltage regulators, gather
environmental data like temperature, power consumption etc. Even
the video output switch (FPGA) is controlled that way.

Nodes describing devices controlled by this infrastructure should
point at the bridge device node:
- bridge phandle:
arm,vexpress,config-bridge = <phandle>;
This property can be also defined in a parent node (eg. for a DCC)
and is effective for all children.


Platform topology
-----------------

As Versatile Express can be configured in number of physically
different setups, the device tree should describe platform topology.
Root node and main motherboard node must define the following
property, describing physical location of the children nodes:
- site number:
arm,vexpress,site = <number>;
where 0 means motherboard, 1 or 2 are daugtherboard sites,
0xf means "master" site (site containing main CPU tile)
- when daughterboards are stacked on one site, their position
in the stack be be described with:
arm,vexpress,position = <number>;
- when describing tiles consisting more than one DCC, its number
can be described with:
arm,vexpress,dcc = <number>;

Any of the numbers above defaults to zero if not defined in
the node or any of its parent.


Motherboard
-----------

The motherboard description file provides a single "motherboard" node
using 2 address cells corresponding to the Static Memory Bus used
between the motherboard and the tile. The first cell defines the Chip
Expand Down Expand Up @@ -87,22 +141,30 @@ can be used to obtain required phandle in the tile's "aliases" node:
- SP804 timers:
v2m_timer01 and v2m_timer23

Current Linux implementation requires a "arm,v2m_timer" alias
pointing at one of the motherboard's SP804 timers, if it is to be
used as the system timer. This alias should be defined in the
motherboard files.
The tile description should define a "smb" node, describing the
Static Memory Bus between the tile and motherboard. It must define
the following properties:
- "simple-bus" compatible value (to ensure creation of the children)
compatible = "simple-bus";
- mapping of the SMB CS/offset addresses into main address space:
#address-cells = <2>;
#size-cells = <1>;
ranges = <...>;
- interrupts mapping:
#interrupt-cells = <1>;
interrupt-map-mask = <0 0 63>;
interrupt-map = <...>;

The tile description must define "ranges", "interrupt-map-mask" and
"interrupt-map" properties to translate the motherboard's address
and interrupt space into one used by the tile's processor.

Abbreviated example:
Example of a VE tile description (simplified)
---------------------------------------------

/dts-v1/;

/ {
model = "V2P-CA5s";
arm,hbi = <0x225>;
arm,vexpress,site = <0xf>;
compatible = "arm,vexpress-v2p-ca5s", "arm,vexpress";
interrupt-parent = <&gic>;
#address-cells = <1>;
Expand Down Expand Up @@ -134,13 +196,29 @@ Abbreviated example:
<0x2c000100 0x100>;
};

motherboard {
dcc {
compatible = "simple-bus";
arm,vexpress,config-bridge = <&v2m_sysreg>;

osc@0 {
compatible = "arm,vexpress-osc";
};
};

smb {
compatible = "simple-bus";

#address-cells = <2>;
#size-cells = <1>;
/* CS0 is visible at 0x08000000 */
ranges = <0 0 0x08000000 0x04000000>;

#interrupt-cells = <1>;
interrupt-map-mask = <0 0 63>;
/* Active high IRQ 0 is connected to GIC's SPI0 */
interrupt-map = <0 0 0 &gic 0 0 4>;

/include/ "vexpress-v2m-rs1.dtsi"
};
};

/include/ "vexpress-v2m-rs1.dtsi"
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