Merge "Documentation: arm: msm: Add snapshot of documentation from 3.10 to 3.18"

* RPM Log

RPM maintains Ulog in the RPM RAM. A device tree node is added

that will hold the address of the RPM RAM region from where

Ulog is read. The physical address from the RPM RAM region

contains a header where various parameters to read the log are

defined. These parameter's offsets in the header are also stored

as a part of the device tree node.

The required properties for rpm-log are:

- compatible: "qcom,rpm-log"

- reg: Specifies the base physical address and the size of the RPM

	registers from where ulog is read.

	Second register(optional) specifies the offset of the rpm

	log start address pointer. If the second register is available,

	the offset value read is added to the first register address

	to read the ulog message.

- qcom,rpm-addr-phys: RPM reads physical address of the RPM RAM region

		differently when compared to Apps. Physical address of

		the RPM RAM region is at an offset when seen from Apps.

		This property specifies the offset which will get added

		to the physical address of RPM RAM to make it

		accessible to the Apps.

- qcom,offset-version: Offset from the start of the phys_addr_base where version

			information is stored.

- qcom,offset-page-buffer-addr: Offset from the start of the phys_addr_base

				where raw log start address is stored. Raw log

				start address is the start of raw log in the

				RPM address space as it should be seen from rpm.

- qcom,offset-log-len: Offset from the start of the phy_addr_base where log

			length is stored.

- qcom,offset-log-len-mask: Offset from the start of the phy_addr_base where

				log length mask is stored.

- qcom,offset-page-indices: Offset from the start of the phy_addr_base where

				index to the writer is stored.

Example 1:

qcom,rpm-log@fc19dc00 {

	compatible = "qcom,rpm-log";

	reg = <0xfc19dc00 0x2000>;

	qcom,offset-rpm-addr = <0xfc000000>;

	qcom,offset-version = <4>;

	qcom,offset-page-buffer-addr = <36>;

	qcom,offset-log-len = <40>;

	qcom,offset-log-len-mask = <44>;

	qcom,offset-page-indices = <56>;

};

Example 2:

qcom,rpm-log@fc000000 {

	compatible = "qcom,rpm-log";

	reg = <0xfc000000 0x2000>,

		<0xfc190018 0x4>;

	qcom,offset-rpm-addr = <0xfc000000>;

	qcom,offset-version = <4>;

	qcom,offset-page-buffer-addr = <36>;

	qcom,offset-log-len = <40>;

	qcom,offset-log-len-mask = <44>;

	qcom,offset-page-indices = <56>;

};

* RPM Master Stats

RPM maintains each master data in RPM message RAM at a specific

offset. It tells about the individual masters information at

any given time like "number of active cores in sub system",

"number of shutdowns" and "wakeup reason for SS" etc. These stats

can be show to the user using the debugfs interface of the kernel.

To achieve this device tree node has been added and it will hold

the address of the RPM RAM from where master stats are read.

Added version number to distinguish the type of data structure

being read from the RAM for different targets.

The required properties for rpm-master-stats are:

- compatible: "qcom,rpm-master-stats".

- reg: The address on the RPM RAM from where stats are read.

- qcom,masters: Each master name.

- qcom,master-offset: Offset required to access each master stats area.

- qcom,master-stats-version: Version number.

Example:

qcom,rpm-stats@fc428150 {

		compatible = "qcom,rpm-stats";

		reg = <0xfc428150 0x1000>;

		qcom,masters = "APSS", "MPSS", "LPSS", "PRONTO";

		qcom,master-offset = <2560>;

		qcom,master-stats-version = <2>;

};