Merge "bindings: arm: msm: Add documentation for sdx ipc driver"

Modem chipset attached to Application processor

Modem chipset can be connected to an external apss processor. The control

channel between the two chipsets consists of gpios that can relay the

state of one subsytem to another. Modem can indicate different events

(bootup/crash etc.) to AP and can get the same information from AP.

Required Properties:

- compatible:	"qcom,sdx-ext-ipc".

Optional named gpio properties:

- qcom,status-out-gpio: gpio to indicate the boot status to remote processor.

- qcom,status-in-gpio: gpio for remote processor to indicate the boot status.

- qcom,status-out2-gpio: gpio to indicate to remote processor that it is in

		E911 call or doing firmware upgrade.

- qcom,default-policy-nop: Set default policy from PANIC to NOP.

- qcom,wakeup-gpio-out: gpio to wakeup remote AP or modem.

- qcom,wakeup-gpio-in: input gpio to receive wakeup signal from remote AP or

		modem.

Example:

	sdx_ext_ipc: qcom,sdx_ext_ipc {

		compatible = "qcom,sdx-ext-ipc";

		qcom,status-in-gpio = <&tlmm 64 0x00>;

		qcom,status-out-gpio = <&tlmm 63 0x00>;

		qcom,status-out2-gpio = <&tlmm 66 0x00>;

		qcom,wakeup-gpio-in = <&tlmm 67 0x00>;

		qcom,wakeup-gpio-out = <&tlmm 68 0x00>;

	};