ath10k architecture
===================

ath10k is a mac80211 driver, the architecture is depicted in the diagram below.

.. image:: ../../../../media/en/users/drivers/ath10k/ath10k-architecture.png

The driver is located in directory drivers/net/wireless/ath/ath10k/. The
source code is available for browsing from this location:

https://github.com/kvalo/ath/tree/master/drivers/net/wireless/ath/ath10k

ath10k components
-----------------

.. image:: ../../../../media/en/users/drivers/ath10k/ath10k-components.png

MAC
~~~

- Files: mac.h mac.c This is the glue layer between mac80211 and ath10k
  lower levels. The interface to mac80211 is implemented through
  ath10k_ops. Data and management frames are sent to HTT, configuration
  commands to WMI.

Host-Target Transport (HTT)
~~~~~~~~~~~~~~~~~~~~~~~~~~~

* Files: htt.c  htt.h  htt_rx.c  htt_tx.c The data path for ath10k.
  Sends frame descriptors to the firmware using HTC. 

Wireless Module Interface (WMI)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

* Files: wmi.h wmi.c The control path for ath10k. Sends all sorts
  configuration commands to the firmware and receives configuration
  events from the firmware. 

Host-Target Communication (HTC)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

* Files: htc.h htc.c Multiplexes the bus for different services. The
  services are defined in enum ath10k_htc_svc_gid. 

Host interconnect Framework (HIF)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

* Files: hif.h Abstracts the access to different bus types. Currently
  only supports PCI, but it's easy to add different bus types. 

Debug
~~~~~

 * Files: debug.h debug.c Component for various debug related to code.
   Currently only log messages and debugfs. 

Tracing
~~~~~~~


* Files: trace.h trace.c Provides tracing data (HTT/WMI packets) etc to
  userspace using Linux tracepoints. trace-cmd is the recommend tool to
  access the tracepoints. 

PCI
~~~

* Files: pci.h pci.c ce.h ce.c 
* Module: ath10k_pci.ko All PCI related code. Interface to HIF happens
  through ath10k_pci_hif_ops. 

Copy Engine (CE)
~~~~~~~~~~~~~~~~

The firmware/ hardware has 8 rings for communication with host, defined in host_ce_config_wlan:

.. code-block:: c

   static const struct ce_attr host_ce_config_wlan[] = {
           /* CE0: host->target HTC control and raw streams */
           {
                   .flags = CE_ATTR_FLAGS,
                   .src_nentries = 16,
                   .src_sz_max = 256,
                   .dest_nentries = 0,
           },

           /* CE1: target->host HTT + HTC control */
           {
                   .flags = CE_ATTR_FLAGS,
                   .src_nentries = 0,
                   .src_sz_max = 512,
                   .dest_nentries = 512,
           },

           /* CE2: target->host WMI */
           {
                   .flags = CE_ATTR_FLAGS,
                   .src_nentries = 0,
                   .src_sz_max = 2048,
                   .dest_nentries = 32,
           },

           /* CE3: host->target WMI */
           {
                   .flags = CE_ATTR_FLAGS,
                   .src_nentries = 32,
                   .src_sz_max = 2048,
                   .dest_nentries = 0,
           },

           /* CE4: host->target HTT */
           {
                   .flags = CE_ATTR_FLAGS | CE_ATTR_DIS_INTR,
                   .src_nentries = CE_HTT_H2T_MSG_SRC_NENTRIES,
                   .src_sz_max = 256,
                   .dest_nentries = 0,
           },

           /* CE5: unused */
           {
                   .flags = CE_ATTR_FLAGS,
                   .src_nentries = 0,
                   .src_sz_max = 0,
                   .dest_nentries = 0,
           },

           /* CE6: target autonomous hif_memcpy */
           {
                   .flags = CE_ATTR_FLAGS,
                   .src_nentries = 0,
                   .src_sz_max = 0,
                   .dest_nentries = 0,
           },

           /* CE7: ce_diag, the Diagnostic Window */
           {
                   .flags = CE_ATTR_FLAGS,
                   .src_nentries = 2,
                   .src_sz_max = DIAG_TRANSFER_LIMIT,
                   .dest_nentries = 2,
           },
   };

Copy Engine provides abstraction for these ring buffers and calls each
ring a pipe.

Bootloader Messaging Interface (BMI)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

* Files: bmi.h bmi.c Firmware upload and everything else which happens
  before firmware is booted. 

Core
~~~~

* Files: core.h core.c Driver initialisation and firmware booting.
  Manages all ath10k components.