soc: qcom: Add snapshot of watchdog_v2 driver

* Qualcomm MSM Watchdog

Watchdog timer is configured with a bark and a bite time.

If the watchdog is not "pet" at regular intervals, the system

is assumed to have become non responsive and needs to be reset.

A warning in the form of a bark timeout leads to a bark interrupt

and a kernel panic. If the watchdog timer is still not reset,

a bite timeout occurs, which is an interrupt in the secure mode,

which leads to a reset of the SOC via the secure watchdog. The

driver needs the petting time, and the bark timeout to be programmed

into the watchdog, as well as the bark and bite irqs.

The device tree parameters for the watchdog are:

Required properties:

- compatible : "qcom,msm-watchdog"

- reg : offset and length of the register set for the watchdog block.

- reg-names : names corresponding to each reg property value.

        "wdt-base" - physical base address of watchdog timer registers

        "wdt-absent-base" - physical base address of watchdog absent register

- interrupts : should contain bark and bite irq numbers

- qcom,pet-time : Non zero time interval at which watchdog should be pet in ms.

- qcom,bark-time : Non zero timeout value for a watchdog bark in ms.

- qcom,userspace-watchdog :

        (boolean) Allow enabling the userspace-watchdog feature. This feature

        requires userspace to pet the watchdog every qcom,pet-time interval

        in addition to the existing kernel-level checks.

        This feature is supported through device sysfs files.

Optional properties:

- qcom,ipi-ping : (boolean) send keep alive ping to other cpus if present

- qcom,wakeup-enable : (boolean) enable non secure watchdog to freeze / unfreeze

                        automatically across suspend / resume path.

Example:

        qcom,wdt@f9017000 {

                compatible = "qcom,msm-watchdog";

                reg = <0xf9017000 0x1000>;

                reg-names = "wdt-base";

                interrupts = <0 3 0>, <0 4 0>;

                qcom,bark-time = <11000>;

                qcom,pet-time = <10000>;

                qcom,ipi-ping;

                qcom,wakeup-enable;

        };

               Meant to be used for debug scenarios only.

               If unsure, say N.

config QCOM_WATCHDOG_V2

	bool "Qualcomm Watchdog Support"

	depends on ARCH_QCOM

	help

	  This enables the watchdog module. It causes kernel panic if the

	  watchdog times out. It allows for detection of cpu hangs and

	  deadlocks. It does not run during the bootup process, so it will

	  not catch any early lockups.

obj-$(CONFIG_SOC_BUS) += socinfo.o

obj-$(CONFIG_MSM_GLADIATOR_HANG_DETECT) += gladiator_hang_detect.o

obj-$(CONFIG_MSM_GLADIATOR_ERP_V2) += gladiator_erp_v2.o

obj-$(CONFIG_QCOM_WATCHDOG_V2) += watchdog_v2.o