net: wwan: t7xx: Devlink documentation

Document the t7xx devlink commands usage for fw flashing &
coredump collection.

Refer to t7xx.rst file for details.

Signed-off-by: M Chetan Kumar <m.chetan.kumar@linux.intel.com>
Signed-off-by: Devegowda Chandrashekar <chandrashekar.devegowda@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/networking/devlink/index.rst

@@ -67,3 +67,4 @@ parameters, info versions, and other features it supports.
    prestera
    iosm
    octeontx2
+   t7xx

Documentation/networking/devlink/t7xx.rst

@@ -0,0 +1,145 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+====================
+t7xx devlink support
+====================
+
+This document describes the devlink features implemented by the ``t7xx``
+device driver.
+
+Flash Update
+============
+
+The ``t7xx`` driver implements the flash update using the ``devlink-flash``
+interface.
+
+The driver uses DEVLINK_SUPPORT_FLASH_UPDATE_COMPONENT to identify the type of
+firmware image that need to be programmed upon the request by user space application.
+
+The supported list of firmware image types is described below.
+
+.. list-table:: Firmware Image types
+    :widths: 15 85
+
+    * - Name
+      - Description
+    * - ``preloader``
+      - The first-stage bootloader image
+    * - ``loader_ext1``
+      - Preloader extension image
+    * - ``tee1``
+      - ARM trusted firmware and TEE (Trusted Execution Environment) image
+    * - ``lk``
+      - The second-stage bootloader image
+    * - ``spmfw``
+      - MediaTek in-house ASIC for power management image
+    * - ``sspm_1``
+      - MediaTek in-house ASIC for power management under secure world image
+    * - ``mcupm_1``
+      - MediaTek in-house ASIC for cpu power management image
+    * - ``dpm_1``
+      - MediaTek in-house ASIC for dram power management image
+    * - ``boot``
+      - The kernel and dtb image
+    * - ``rootfs``
+      - Root filesystem image
+    * - ``md1img``
+      - Modem image
+    * - ``md1dsp``
+      - Modem DSP image
+    * - ``mcf1``
+      - Modem OTA image (Modem Configuration Framework) for operators
+    * - ``mcf2``
+      - Modem OTA image (Modem Configuration Framework) for OEM vendors
+    * - ``mcf3``
+      - Modem OTA image (other usage) for OEM configurations
+
+``t7xx`` driver uses fastboot protocol for fw flashing. In the fw flashing
+procedure, fastboot command's & response's are exchanged between driver
+and wwan device.
+
+The wwan device is put into fastboot mode via devlink reload command, by
+passing "driver_reinit" action.
+
+$ devlink dev reload pci/0000:$bdf action driver_reinit
+
+Upon completion of fw flashing or coredump collection the wwan device is
+reset to normal mode using devlink reload command, by passing "fw_activate"
+action.
+
+$ devlink dev reload pci/0000:$bdf action fw_activate
+
+Flash Commands:
+===============
+
+$ devlink dev flash pci/0000:$bdf file preloader_k6880v1_mdot2_datacard.bin component "preloader"
+
+$ devlink dev flash pci/0000:$bdf file loader_ext-verified.img component "loader_ext1"
+
+$ devlink dev flash pci/0000:$bdf file tee-verified.img component "tee1"
+
+$ devlink dev flash pci/0000:$bdf file lk-verified.img component "lk"
+
+$ devlink dev flash pci/0000:$bdf file spmfw-verified.img component "spmfw"
+
+$ devlink dev flash pci/0000:$bdf file sspm-verified.img component "sspm_1"
+
+$ devlink dev flash pci/0000:$bdf file mcupm-verified.img component "mcupm_1"
+
+$ devlink dev flash pci/0000:$bdf file dpm-verified.img component "dpm_1"
+
+$ devlink dev flash pci/0000:$bdf file boot-verified.img component "boot"
+
+$ devlink dev flash pci/0000:$bdf file root.squashfs component "rootfs"
+
+$ devlink dev flash pci/0000:$bdf file modem-verified.img component "md1img"
+
+$ devlink dev flash pci/0000:$bdf file dsp-verified.bin component "md1dsp"
+
+$ devlink dev flash pci/0000:$bdf file OP_OTA.img component "mcf1"
+
+$ devlink dev flash pci/0000:$bdf file OEM_OTA.img component "mcf2"
+
+$ devlink dev flash pci/0000:$bdf file DEV_OTA.img component "mcf3"
+
+Note: component "value" represents the partition type to be programmed.
+
+Regions
+=======
+
+The ``t7xx`` driver supports core dump collection when device encounters
+an exception. When wwan device encounters an exception, a snapshot of device
+internal data will be taken by the driver using fastboot commands.
+
+Following regions are accessed for device internal data.
+
+.. list-table:: Regions implemented
+    :widths: 15 85
+
+    * - Name
+      - Description
+    * - ``mr_dump``
+      - The detailed modem components log are captured in this region
+    * - ``lk_dump``
+      - This region dumps the current snapshot of lk
+
+
+Region commands
+===============
+
+$ devlink region show
+
+
+$ devlink region new mr_dump
+
+$ devlink region read mr_dump snapshot 0 address 0 length $len
+
+$ devlink region del mr_dump snapshot 0
+
+$ devlink region new lk_dump
+
+$ devlink region read lk_dump snapshot 0 address 0 length $len
+
+$ devlink region del lk_dump snapshot 0
+
+Note: $len is actual len to be dumped.