powerpc: Add documentation for CPM GPIO banks

Signed-off-by: Jochen Friedrich <jochen@scram.de>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
This commit is contained in:
Jochen Friedrich 2008-07-05 13:29:28 +02:00 committed by Kumar Gala
parent 89ae5b2b93
commit ade254d7f0

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Every GPIO controller node must have #gpio-cells property defined,
this information will be used to translate gpio-specifiers.
On CPM1 devices, all ports are using slightly different register layouts.
Ports A, C and D are 16bit ports and Ports B and E are 32bit ports.
On CPM2 devices, all ports are 32bit ports and use a common register layout.
Required properties:
- compatible : "fsl,cpm1-pario-bank-a", "fsl,cpm1-pario-bank-b",
"fsl,cpm1-pario-bank-c", "fsl,cpm1-pario-bank-d",
"fsl,cpm1-pario-bank-e", "fsl,cpm2-pario-bank"
- #gpio-cells : Should be two. The first cell is the pin number and the
second cell is used to specify optional paramters (currently unused).
- gpio-controller : Marks the port as GPIO controller.
Example of three SOC GPIO banks defined as gpio-controller nodes:
CPM1_PIO_A: gpio-controller@950 {
#gpio-cells = <2>;
compatible = "fsl,cpm1-pario-bank-a";
reg = <0x950 0x10>;
gpio-controller;
};
CPM1_PIO_B: gpio-controller@ab8 {
#gpio-cells = <2>;
compatible = "fsl,cpm1-pario-bank-b";
reg = <0xab8 0x10>;
gpio-controller;
};
CPM1_PIO_E: gpio-controller@ac8 {
#gpio-cells = <2>;
compatible = "fsl,cpm1-pario-bank-e";
reg = <0xac8 0x18>;
gpio-controller;
};