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Commit c913d6af authored by Eric Holmberg's avatar Eric Holmberg Committed by Gerrit - the friendly Code Review server
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msm: smp2p: update documentation 



Updates to the SMP2P documentation to:
 * Add link to the Device Tree documentation
 * Add Subsystem Restart Description
 * Correct SMEM IDs

Change-Id: I81bf9fe66c6c3649b44616c2764400f91b68778c
Signed-off-by: default avatarEric Holmberg <eholmber@codeaurora.org>
parent def6c024

Documentation/arm/msm/msm_smp2p.txt

+24 −11
Original line number Diff line number Diff line
@@ -299,6 +299,12 @@ trigger SMP2P to: 
       has changed.

    2) Compare Entries Valid to cached value.  If changed, initialize new entries.



Security

========

Since the implementation resides in the kernel and does not expose interfaces

to userspace, no security issues are anticipated.  The usage of separate SMEM

items allows for future security enhancements in SMEM.



Performance

===========

No performance issues are anticipated as the signaling rate is expected to be
@@ -314,16 +320,15 @@ Tree: 
    1) A node that matches "qcom,smp2pgpio" to create the entry

    2) A node that matches the client driver to provide the GPIO pin mapping



The details of the device tree entries are contained in the file

Documentionat/devicetree/bindings/arm/msm/smp2p.txt.



The details of the device tree entries for the GPIO interface are contained in

the file Documentation/devicetree/bindings/gpio/gpio-smp2p.txt.



    /* SMP2P Test Driver for inbound entry. */

    smp2pgpio_smp2p_7_in: qcom,smp2pgpio-smp2p-7-in {

        compatible = "qcom,smp2pgpio";

        qcom,entry-name = "smp2p";

        qcom,remote-pid = <7>;

        qcom,is_inbound;

        qcom,is-inbound;

        gpio-controller;

        #gpio-cells = <2>;

        interrupt-controller;
@@ -374,6 +379,13 @@ calls are shown below: 


Please reference the unit test code for example usage.



Subsystem Restart

=================

SMP2P is unaffected by SubSystem Restart (SSR) on the high-level OS side and is

actually used as an underlying communication mechanism for SSR.  On the

peripheral system that is being restarted, SMP2P will zero out all existing

state entries upon reboot as part of the SMP2P initialization process.



Debug

=====

The state values and names for all entries accessible by the Apps are
@@ -395,12 +407,13 @@ One module parameter will be provided to change the verbosity of internal loggin 


Config options

==============

Configuration of interrupts will be done using Device Tree.  By default, the

testing components will be enabled since it does not affect performance and has

a minimal impact on kernel size.  However, customers can disable the testing

components for size optimization.

Configuration of interrupts will be done using Device Tree per the format in

Documentation/devicetree/bindings/arm/msm/smp2p.txt.  By default, the testing

components will be enabled since it does not affect performance and has a

minimal impact on kernel size.  However, customers can disable the testing

component for size optimization.



    CONFIG_MSM_SMP2P - enables SMP2P core functionality

    CONFIG_MSM_SMP2P - enables SMP2P

    CONFIG_MSM_SMP2P_TEST - enables unit test support



Dependencies