bt8xx.rst

  1.. SPDX-License-Identifier: GPL-2.0
  2
  3==================================
  4How to get the bt8xx cards working
  5==================================
  6
  7Authors:
  8	 Richard Walker,
  9	 Jamie Honan,
 10	 Michael Hunold,
 11	 Manu Abraham,
 12	 Uwe Bugla,
 13	 Michael Krufky
 14
 15General information
 16-------------------
 17
 18This class of cards has a bt878a as the PCI interface, and require the bttv
 19driver for accessing the i2c bus and the gpio pins of the bt8xx chipset.
 20
 21Please see Documentation/admin-guide/media/bttv-cardlist.rst for a complete
 22list of Cards based on the Conexant Bt8xx PCI bridge supported by the
 23Linux Kernel.
 24
 25In order to be able to compile the kernel, some config options should be
 26enabled::
 27
 28    ./scripts/config -e PCI
 29    ./scripts/config -e INPUT
 30    ./scripts/config -m I2C
 31    ./scripts/config -m MEDIA_SUPPORT
 32    ./scripts/config -e MEDIA_PCI_SUPPORT
 33    ./scripts/config -e MEDIA_ANALOG_TV_SUPPORT
 34    ./scripts/config -e MEDIA_DIGITAL_TV_SUPPORT
 35    ./scripts/config -e MEDIA_RADIO_SUPPORT
 36    ./scripts/config -e RC_CORE
 37    ./scripts/config -m VIDEO_BT848
 38    ./scripts/config -m DVB_BT8XX
 39
 40If you want to automatically support all possible variants of the Bt8xx
 41cards, you should also do::
 42
 43    ./scripts/config -e MEDIA_SUBDRV_AUTOSELECT
 44
 45.. note::
 46
 47   Please use the following options with care as deselection of drivers which
 48   are in fact necessary may result in DVB devices that cannot be tuned due
 49   to lack of driver support.
 50
 51If your goal is to just support an specific board, you may, instead,
 52disable MEDIA_SUBDRV_AUTOSELECT and manually select the frontend drivers
 53required by your board. With that, you can save some RAM.
 54
 55You can do that by calling make xconfig/qconfig/menuconfig and look at
 56the options on those menu options (only enabled if
 57``Autoselect ancillary drivers`` is disabled:
 58
 59#) ``Device drivers`` => ``Multimedia support`` => ``Customize TV tuners``
 60#) ``Device drivers`` => ``Multimedia support`` => ``Customize DVB frontends``
 61
 62Then, on each of the above menu, please select your card-specific
 63frontend and tuner modules.
 64
 65
 66Loading Modules
 67---------------
 68
 69Regular case: If the bttv driver detects a bt8xx-based DVB card, all
 70frontend and backend modules will be loaded automatically.
 71
 72Exceptions are:
 73
 74- Old TV cards without EEPROMs, sharing a common PCI subsystem ID;
 75- Old TwinHan DST cards or clones with or without CA slot and not
 76  containing an Eeprom.
 77
 78In the following cases overriding the PCI type detection for bttv and
 79for dvb-bt8xx drivers by passing modprobe parameters may be necessary.
 80
 81Running TwinHan and Clones
 82~~~~~~~~~~~~~~~~~~~~~~~~~~
 83
 84As shown at Documentation/admin-guide/media/bttv-cardlist.rst, TwinHan and
 85clones use ``card=113`` modprobe parameter. So, in order to properly
 86detect it for devices without EEPROM, you should use::
 87
 88	$ modprobe bttv card=113
 89	$ modprobe dst
 90
 91Useful parameters for verbosity level and debugging the dst module::
 92
 93	verbose=0:		messages are disabled
 94		1:		only error messages are displayed
 95		2:		notifications are displayed
 96		3:		other useful messages are displayed
 97		4:		debug setting
 98	dst_addons=0:		card is a free to air (FTA) card only
 99		0x20:	card has a conditional access slot for scrambled channels
100	dst_algo=0:		(default) Software tuning algorithm
101	         1:		Hardware tuning algorithm
102
103
104The autodetected values are determined by the cards' "response string".
105
106In your logs see f. ex.: dst_get_device_id: Recognize [DSTMCI].
107
108For bug reports please send in a complete log with verbose=4 activated.
109Please also see Documentation/admin-guide/media/ci.rst.
110
111Running multiple cards
112~~~~~~~~~~~~~~~~~~~~~~
113
114See Documentation/admin-guide/media/bttv-cardlist.rst for a complete list of
115Card ID. Some examples:
116
117	===========================	===
118	Brand name			ID
119	===========================	===
120	Pinnacle PCTV Sat		 94
121	Nebula Electronics Digi TV	104
122	pcHDTV HD-2000 TV		112
123	Twinhan DST and clones		113
124	Avermedia AverTV DVB-T 77:	123
125	Avermedia AverTV DVB-T 761	124
126	DViCO FusionHDTV DVB-T Lite	128
127	DViCO FusionHDTV 5 Lite		135
128	===========================	===
129
130.. note::
131
132   When you have multiple cards, the order of the card ID should
133   match the order where they're detected by the system. Please notice
134   that removing/inserting other PCI cards may change the detection
135   order.
136
137Example::
138
139	$ modprobe bttv card=113 card=135
140
141In case of further problems please subscribe and send questions to
142the mailing list: linux-media@vger.kernel.org.
143
144Probing the cards with broken PCI subsystem ID
145~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
146
147There are some TwinHan cards whose EEPROM has become corrupted for some
148reason. The cards do not have a correct PCI subsystem ID.
149Still, it is possible to force probing the cards with::
150
151	$ echo 109e 0878 $subvendor $subdevice > \
152		/sys/bus/pci/drivers/bt878/new_id
153
154The two numbers there are::
155
156	109e: PCI_VENDOR_ID_BROOKTREE
157	0878: PCI_DEVICE_ID_BROOKTREE_878