Merge master.kernel.org:/pub/scm/linux/kernel/git/mchehab/v4l-dvb

* master.kernel.org:/pub/scm/linux/kernel/git/mchehab/v4l-dvb: (244 commits)
  V4L/DVB (4210b): git-dvb: tea575x-tuner build fix
  V4L/DVB (4210a): git-dvb versus matroxfb
  V4L/DVB (4209): Added some BTTV PCI IDs for newer boards
  Fixes some sync issues between V4L/DVB development and GIT
  V4L/DVB (4206): Cx88-blackbird: always set encoder height based on tvnorm->id
  V4L/DVB (4205): Merge tda9887 module into tuner.
  V4L/DVB (4203): Explicitly set the enum values.
  V4L/DVB (4202): allow selecting CX2341x port mode
  V4L/DVB (4200): Disable bitrate_mode when encoding mpeg-1.
  V4L/DVB (4199): Add cx2341x-specific control array to cx2341x.c
  V4L/DVB (4198): Avoid newer usages of obsoleted experimental MPEGCOMP API
  V4L/DVB (4197): Port new MPEG API to saa7134-empress with saa6752hs
  V4L/DVB (4196): Port cx88-blackbird to the new MPEG API.
  V4L/DVB (4193): Update cx2341x fw encoding API doc.
  V4L/DVB (4192): Use control helpers for saa7115, cx25840, msp3400.
  V4L/DVB (4191): Add CX2341X MPEG encoder module.
  V4L/DVB (4190): Add helper functions for control processing to v4l2-common.
  V4L/DVB (4189): Add videodev support for VIDIOC_S/G/TRY_EXT_CTRLS.
  V4L/DVB (4188): Add new MPEG control/ioctl definitions to videodev2.h
  V4L/DVB (4186): Add support for the DNTV Live! mini DVB-T card.
  ...

1 files changed, 69 insertions, 0 deletions

diff --git a/Documentation/video4linux/cx2341x/fw-calling.txt b/Documentation/video4linux/cx2341x/fw-calling.txt
new file mode 100644
index 000000000000..8d21181de537
--- /dev/null
+++ b/Documentation/video4linux/cx2341x/fw-calling.txt
@@ -0,0 +1,69 @@
+This page describes how to make calls to the firmware api.
+
+How to call
+===========
+
+The preferred calling convention is known as the firmware mailbox. The
+mailboxes are basically a fixed length array that serves as the call-stack.
+
+Firmware mailboxes can be located by searching the encoder and decoder memory
+for a 16 byte signature. That signature will be located on a 256-byte boundary.
+
+Signature:
+0x78, 0x56, 0x34, 0x12, 0x12, 0x78, 0x56, 0x34,
+0x34, 0x12, 0x78, 0x56, 0x56, 0x34, 0x12, 0x78
+
+The firmware implements 20 mailboxes of 20 32-bit words. The first 10 are
+reserved for API calls. The second 10 are used by the firmware for event
+notification.
+
+  Index  Name
+  -----  ----
+  0      Flags
+  1      Command
+  2      Return value
+  3      Timeout
+  4-19   Parameter/Result
+
+
+The flags are defined in the following table. The direction is from the
+perspective of the firmware.
+
+  Bit  Direction  Purpose
+  ---  ---------  -------
+  2    O          Firmware has processed the command.
+  1    I          Driver has finished setting the parameters.
+  0    I          Driver is using this mailbox.
+
+
+The command is a 32-bit enumerator. The API specifics may be found in the
+fw-*-api.txt documents.
+
+The return value is a 32-bit enumerator. Only two values are currently defined:
+0=success and -1=command undefined.
+
+There are 16 parameters/results 32-bit fields. The driver populates these fields
+with values for all the parameters required by the call. The driver overwrites
+these fields with result values returned by the call. The API specifics may be
+found in the fw-*-api.txt documents.
+
+The timeout value protects the card from a hung driver thread. If the driver
+doesn't handle the completed call within the timeout specified, the firmware
+will reset that mailbox.
+
+To make an API call, the driver iterates over each mailbox looking for the
+first one available (bit 0 has been cleared). The driver sets that bit, fills
+in the command enumerator, the timeout value and any required parameters. The
+driver then sets the parameter ready bit (bit 1). The firmware scans the
+mailboxes for pending commands, processes them, sets the result code, populates
+the result value array with that call's return values and sets the call
+complete bit (bit 2). Once bit 2 is set, the driver should retrieve the results
+and clear all the flags. If the driver does not perform this task within the
+time set in the timeout register, the firmware will reset that mailbox.
+
+Event notifications are sent from the firmware to the host. The host tells the
+firmware which events it is interested in via an API call. That call tells the
+firmware which notification mailbox to use. The firmware signals the host via
+an interrupt. Only the 16 Results fields are used, the Flags, Command, Return
+value and Timeout words are not used.
+