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-rw-r--r--Documentation/admin-guide/media/cardlist.rst116
1 files changed, 111 insertions, 5 deletions
diff --git a/Documentation/admin-guide/media/cardlist.rst b/Documentation/admin-guide/media/cardlist.rst
index 527188ee9697..025d251764c2 100644
--- a/Documentation/admin-guide/media/cardlist.rst
+++ b/Documentation/admin-guide/media/cardlist.rst
@@ -1,22 +1,128 @@
.. SPDX-License-Identifier: GPL-2.0
+==========
Cards List
==========
+The media subsystem provide support for lots of PCI and USB drivers, plus
+platform-specific drivers. It also contains several ancillary I²C drivers.
+
+The platform-specific drivers are usually present on embedded systems,
+or are supported by the main board. Usually, setting them is done via
+OpenFirmware or ACPI.
+
+The PCI and USB drivers, however, are independent of the system's board,
+and may be added/removed by the user.
+
+This section contains a list of supported PCI and USB boards.
+
+Please notice that this list is not exaustive.
+
+USB drivers
+===========
+
+The USB boards are identified by an identification called USB ID.
+
+The ``lsusb`` command allows identifying the USB IDs::
+
+ $ lsusb
+ ...
+ Bus 001 Device 015: ID 046d:082d Logitech, Inc. HD Pro Webcam C920
+ Bus 001 Device 074: ID 2040:b131 Hauppauge
+ Bus 001 Device 075: ID 2013:024f PCTV Systems nanoStick T2 290e
+ ...
+
+Newer camera devices use a standard way to expose themselves as such,
+via USB Video Class. Those cameras are automatically supported by the
+``uvc-driver``.
+
+Older cameras and TV USB devices uses USB Vendor Classes: each vendor
+defines its own way to access the device. This section contains
+card lists for such vendor-class devices.
+
+While this is not as common as on PCI, sometimes the same USB ID is used
+by different products. So, several media drivers allow passing a ``card=``
+parameter, in order to setup a card number that would match the correct
+settings for an specific product type.
+
.. toctree::
:maxdepth: 1
au0828-cardlist
+ cx231xx-cardlist
+ em28xx-cardlist
+ tm6000-cardlist
+ usbvision-cardlist
+ gspca-cardlist
+
+PCI drivers
+===========
+
+The PCI boards are identified by an identification called PCI ID. The PCI ID
+is actually composed by two parts:
+
+ - Vendor ID and device ID;
+ - Subsystem ID and Subsystem device ID;
+
+The ``lspci -nn`` command allows identifying the vendor/device PCI IDs::
+
+ $ lspci -nn
+ ...
+ 00:0b.0 Multimedia controller [0480]: Brooktree Corporation Bt878 Audio Capture [109e:0878] (rev 11)
+ 01:00.0 Multimedia video controller [0400]: Conexant Systems, Inc. CX23887/8 PCIe Broadcast Audio and Video Decoder with 3D Comb [14f1:8880] (rev 0f)
+ 01:01.0 Multimedia controller [0480]: Philips Semiconductors SAA7131/SAA7133/SAA7135 Video Broadcast Decoder [1131:7133] (rev d1)
+ 02:01.0 Multimedia video controller [0400]: Internext Compression Inc iTVC15 (CX23415) Video Decoder [4444:0803] (rev 01)
+ 02:02.0 Multimedia video controller [0400]: Conexant Systems, Inc. CX23418 Single-Chip MPEG-2 Encoder with Integrated Analog Video/Broadcast Audio Decoder [14f1:5b7a]
+ 02:03.0 Multimedia video controller [0400]: Brooktree Corporation Bt878 Video Capture [109e:036e] (rev 11)
+ ...
+
+The subsystem IDs can be obtained using ``lspci -vn``
+
+.. code-block:: none
+ :emphasize-lines: 4
+
+ $ lspci -vn
+ ...
+ 01:01.0 0480: 1131:7133 (rev d1)
+ Subsystem: 1461:f01d
+ Flags: bus master, medium devsel, latency 32, IRQ 209
+ Memory at e2002000 (32-bit, non-prefetchable) [size=2K]
+ Capabilities: [40] Power Management version 2
+ ...
+
+Unfortunately, sometimes the same PCI ID is used by different products.
+So, several media drivers allow passing a ``card=`` parameter, in order
+to setup a card number that would match the correct settings for an
+specific board.
+
+.. toctree::
+ :maxdepth: 1
+
bttv-cardlist
cx18-cardlist
- cx231xx-cardlist
cx23885-cardlist
cx88-cardlist
- em28xx-cardlist
ivtv-cardlist
saa7134-cardlist
saa7164-cardlist
- tm6000-cardlist
+
+I²C drivers
+===========
+
+The I²C (Inter-Integrated Circuit) bus is a three-wires bus used internally
+at the media cards for communication between different chips. While the bus
+is not visible to the Linux Kernel, drivers need to send and receive
+commands via the bus. The Linux Kernel driver abstraction has support to
+implement different drivers for each component inside an I²C bus, as if
+the bus were visible to the main system board.
+
+One of the problems with I²C devices is that sometimes the same device may
+work with different I²C hardware. This is common, for example, on devices
+that comes with a tuner for North America market, and another one for
+Europe. Some drivers have a ``tuner=`` modprobe parameter to allow using a
+different tuner number in order to address such issue.
+
+.. toctree::
+ :maxdepth: 1
+
tuner-cardlist
- usbvision-cardlist
- gspca-cardlist