net: wwan: iosm: devlink fw flashing & cd collection documentation

Documents devlink params, fw update & cd collection commands
and its usage.
Signed-off-by: M Chetan Kumar <m.chetan.kumar@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/networking/devlink/index.rst

@@ -47,3 +47,4 @@ parameters, info versions, and other features it supports.
    ti-cpsw-switch
    am65-nuss-cpsw-switch
    prestera
+   iosm

Documentation/networking/devlink/iosm.rst

+.. SPDX-License-Identifier: GPL-2.0
+
+====================
+iosm devlink support
+====================
+
+This document describes the devlink features implemented by the ``iosm``
+device driver.
+
+Parameters
+==========
+
+The ``iosm`` driver implements the following driver-specific parameters.
+
+.. list-table:: Driver-specific parameters implemented
+   :widths: 5 5 5 85
+
+   * - Name
+     - Type
+     - Mode
+     - Description
+   * - ``erase_full_flash``
+     - u8
+     - runtime
+     - erase_full_flash parameter is used to check if full erase is required for
+       the device during firmware flashing.
+       If set, Full nand erase command will be sent to the device. By default,
+       only conditional erase support is enabled.
+   * - ``download_region``
+     - u8
+     - runtime
+     - download_region parameter is used to identify if we are flashing the
+       loadmap/region file during the firmware flashing.
+   * - ``address``
+     - u32
+     - runtime
+     - address parameter is used to send the address information of the
+       loadmap/region file which is required during the firmware flashing
+       process. Each region file has be flashed to its respective flash address.
+   * - ``region_count``
+     - u8
+     - runtime
+     - region_count parameter is used to inform the driver on how many total
+       loadmap/region files are present in modem firmware image that has to be
+       flashed.
+
+
+Flash Update
+============
+
+The ``iosm`` driver implements support for flash update using the
+``devlink-flash`` interface.
+
+It supports updating the device flash using a combined flash image which contains
+the Bootloader images and other modem software images.
+
+The driver uses DEVLINK_SUPPORT_FLASH_UPDATE_COMPONENT to identify type of
+firmware image that need to be flashed as requested by user space application.
+Supported firmware image types.
+
+.. list-table:: Firmware Image types
+    :widths: 15 85
+
+    * - Name
+      - Description
+    * - ``PSI RAM``
+      - Primary Signed Image
+    * - ``EBL``
+      - External Bootloader
+    * - ``FLS``
+      - Modem Software Image
+
+PSI RAM and EBL are the RAM images which are injected to the device when the
+device is in BOOT ROM stage. Once this is successful, the actual modem firmware
+image is flashed to the device. The modem software image contains multiple files
+each having one secure bin file and at least one Loadmap/Region file. For flashing
+these files, appropriate commands are sent to the modem device along with the
+data required for flashing. The data like region count and address of each region
+has to be passed to the driver using the devlink param command.
+
+If the device has to be fully erased before firmware flashing, user application
+need to set the erase_full_flash parameter using devlink param command.
+By default, conditional erase feature is supported.
+
+Flash Commands:
+===============
+1) When modem is in Boot ROM stage, user can use below command to inject PSI RAM
+image using devlink flash command.
+
+$ devlink dev flash pci/0000:02:00.0 file <PSI_RAM_File_name> component PSI
+
+2) If user want to do a full erase, below command need to be issued to set the
+erase full flash param (To be set only if full erase required).
+
+$ devlink dev param set pci/0000:02:00.0 name erase_full_flash value true cmode runtime
+
+3) Inject EBL after the modem is in PSI stage.
+$ devlink dev flash pci/0000:02:00.0 file <EBL_File_name> component EBL
+
+4) Once EBL is injected successfully, then the actual firmware flashing takes
+place. Below is the sequence of commands used for each of the firmware images.
+
+a) Flash secure bin file.
+$ devlink dev flash pci/0000:02:00.0 file <Secure_bin_file_name> component FLS
+
+b) Flashing the Loadmap/Region file
+$ devlink dev param set pci/0000:02:00.0 name region_count value 1 cmode runtime
+
+$ devlink dev param set pci/0000:02:00.0 name download_region value true cmode runtime
+
+$ devlink dev param set pci/0000:02:00.0 name address value <Nand_address> cmode runtime
+
+$ devlink dev flash pci/0000:02:00.0 file <Load_map_file_name> component FLS
+
+Regions
+=======
+
+The ``iosm`` driver supports dumping the coredump logs.
+
+In case a firmware encounters an exception, a snapshot will be taken by the
+driver. Following regions are accessed for device internal data.
+
+.. list-table:: Regions implemented
+    :widths: 15 85
+
+    * - Name
+      - Description
+    * - ``report.json``
+      - The summary of exception details logged as part of this region.
+    * - ``coredump.fcd``
+      - This region contains the details related to the exception occurred in the
+        device (RAM dump).
+    * - ``cdd.log``
+      - This region contains the logs related to the modem CDD driver.
+    * - ``eeprom.bin``
+      - This region contains the eeprom logs.
+    * - ``bootcore_trace.bin``
+      -  This region contains the current instance of bootloader logs.
+    * - ``bootcore_prev_trace.bin``
+      - This region contains the previous instance of bootloader logs.
+
+
+Region commands
+===============
+
+$ devlink region show
+
+$ devlink region new pci/0000:02:00.0/report.json
+
+$ devlink region dump pci/0000:02:00.0/report.json snapshot 0
+
+$ devlink region del pci/0000:02:00.0/report.json snapshot 0
+
+$ devlink region new pci/0000:02:00.0/coredump.fcd
+
+$ devlink region dump pci/0000:02:00.0/coredump.fcd snapshot 1
+
+$ devlink region del pci/0000:02:00.0/coredump.fcd snapshot 1
+
+$ devlink region new pci/0000:02:00.0/cdd.log
+
+$ devlink region dump pci/0000:02:00.0/cdd.log snapshot 2
+
+$ devlink region del pci/0000:02:00.0/cdd.log snapshot 2
+
+$ devlink region new pci/0000:02:00.0/eeprom.bin
+
+$ devlink region dump pci/0000:02:00.0/eeprom.bin snapshot 3
+
+$ devlink region del pci/0000:02:00.0/eeprom.bin snapshot 3
+
+$ devlink region new pci/0000:02:00.0/bootcore_trace.bin
+
+$ devlink region dump pci/0000:02:00.0/bootcore_trace.bin snapshot 4
+
+$ devlink region del pci/0000:02:00.0/bootcore_trace.bin snapshot 4
+
+$ devlink region new pci/0000:02:00.0/bootcore_prev_trace.bin
+
+$ devlink region dump pci/0000:02:00.0/bootcore_prev_trace.bin snapshot 5
+
+$ devlink region del pci/0000:02:00.0/bootcore_prev_trace.bin snapshot 5