diff options
author | Mauro Carvalho Chehab <mchehab+huawei@kernel.org> | 2020-03-05 07:25:55 +0100 |
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committer | Mauro Carvalho Chehab <mchehab+huawei@kernel.org> | 2020-04-14 10:29:06 +0200 |
commit | 51df01acc193084430543db71c69f19827191752 (patch) | |
tree | 96ce499ab64a141e41d12ab549f5d496735d677f /Documentation/media | |
parent | 481025598f214eea371a2aa9cf2464ed786b7555 (diff) | |
download | linux-51df01acc193084430543db71c69f19827191752.tar.bz2 |
media: docs: split development info from cx88.rst
This file contains both admin and development stuff. Split on
two, as they're usually read by different audiences.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Diffstat (limited to 'Documentation/media')
-rw-r--r-- | Documentation/media/v4l-drivers/cx88-devel.rst | 113 | ||||
-rw-r--r-- | Documentation/media/v4l-drivers/cx88.rst | 107 | ||||
-rw-r--r-- | Documentation/media/v4l-drivers/index.rst | 1 |
3 files changed, 114 insertions, 107 deletions
diff --git a/Documentation/media/v4l-drivers/cx88-devel.rst b/Documentation/media/v4l-drivers/cx88-devel.rst new file mode 100644 index 000000000000..cfe7c03f4930 --- /dev/null +++ b/Documentation/media/v4l-drivers/cx88-devel.rst @@ -0,0 +1,113 @@ +.. SPDX-License-Identifier: GPL-2.0 + +The cx88 driver +=============== + +Author: Gerd Hoffmann + +Documentation missing at the cx88 datasheet +------------------------------------------- + +MO_OUTPUT_FORMAT (0x310164) + +.. code-block:: none + + Previous default from DScaler: 0x1c1f0008 + Digit 8: 31-28 + 28: PREVREMOD = 1 + + Digit 7: 27-24 (0xc = 12 = b1100 ) + 27: COMBALT = 1 + 26: PAL_INV_PHASE + (DScaler apparently set this to 1, resulted in sucky picture) + + Digits 6,5: 23-16 + 25-16: COMB_RANGE = 0x1f [default] (9 bits -> max 512) + + Digit 4: 15-12 + 15: DISIFX = 0 + 14: INVCBF = 0 + 13: DISADAPT = 0 + 12: NARROWADAPT = 0 + + Digit 3: 11-8 + 11: FORCE2H + 10: FORCEREMD + 9: NCHROMAEN + 8: NREMODEN + + Digit 2: 7-4 + 7-6: YCORE + 5-4: CCORE + + Digit 1: 3-0 + 3: RANGE = 1 + 2: HACTEXT + 1: HSFMT + +0x47 is the sync byte for MPEG-2 transport stream packets. +Datasheet incorrectly states to use 47 decimal. 188 is the length. +All DVB compliant frontends output packets with this start code. + +Hauppauge WinTV cx88 IR information +----------------------------------- + +The controls for the mux are GPIO [0,1] for source, and GPIO 2 for muting. + +====== ======== ================================================= +GPIO0 GPIO1 +====== ======== ================================================= + 0 0 TV Audio + 1 0 FM radio + 0 1 Line-In + 1 1 Mono tuner bypass or CD passthru (tuner specific) +====== ======== ================================================= + +GPIO 16(I believe) is tied to the IR port (if present). + + +From the data sheet: + +- Register 24'h20004 PCI Interrupt Status + + - bit [18] IR_SMP_INT Set when 32 input samples have been collected over + - gpio[16] pin into GP_SAMPLE register. + +What's missing from the data sheet: + +- Setup 4KHz sampling rate (roughly 2x oversampled; good enough for our RC5 + compat remote) +- set register 0x35C050 to 0xa80a80 +- enable sampling +- set register 0x35C054 to 0x5 +- enable the IRQ bit 18 in the interrupt mask register (and + provide for a handler) + +GP_SAMPLE register is at 0x35C058 + +Bits are then right shifted into the GP_SAMPLE register at the specified +rate; you get an interrupt when a full DWORD is received. +You need to recover the actual RC5 bits out of the (oversampled) IR sensor +bits. (Hint: look for the 0/1and 1/0 crossings of the RC5 bi-phase data) An +actual raw RC5 code will span 2-3 DWORDS, depending on the actual alignment. + +I'm pretty sure when no IR signal is present the receiver is always in a +marking state(1); but stray light, etc can cause intermittent noise values +as well. Remember, this is a free running sample of the IR receiver state +over time, so don't assume any sample starts at any particular place. + +Additional info +~~~~~~~~~~~~~~~ + +This data sheet (google search) seems to have a lovely description of the +RC5 basics: +http://www.atmel.com/dyn/resources/prod_documents/doc2817.pdf + +This document has more data: +http://www.nenya.be/beor/electronics/rc5.htm + +This document has a how to decode a bi-phase data stream: +http://www.ee.washington.edu/circuit_archive/text/ir_decode.txt + +This document has still more info: +http://www.xs4all.nl/~sbp/knowledge/ir/rc5.htm diff --git a/Documentation/media/v4l-drivers/cx88.rst b/Documentation/media/v4l-drivers/cx88.rst index 698c73ea2e36..e4badb18199d 100644 --- a/Documentation/media/v4l-drivers/cx88.rst +++ b/Documentation/media/v4l-drivers/cx88.rst @@ -56,110 +56,3 @@ the driver. What to do then? trial-and-error using the tuner=<n> insmod option. If you know which one the card has you can also have a look at the list in CARDLIST.tuner - -Documentation missing at the cx88 datasheet -------------------------------------------- - -MO_OUTPUT_FORMAT (0x310164) - -.. code-block:: none - - Previous default from DScaler: 0x1c1f0008 - Digit 8: 31-28 - 28: PREVREMOD = 1 - - Digit 7: 27-24 (0xc = 12 = b1100 ) - 27: COMBALT = 1 - 26: PAL_INV_PHASE - (DScaler apparently set this to 1, resulted in sucky picture) - - Digits 6,5: 23-16 - 25-16: COMB_RANGE = 0x1f [default] (9 bits -> max 512) - - Digit 4: 15-12 - 15: DISIFX = 0 - 14: INVCBF = 0 - 13: DISADAPT = 0 - 12: NARROWADAPT = 0 - - Digit 3: 11-8 - 11: FORCE2H - 10: FORCEREMD - 9: NCHROMAEN - 8: NREMODEN - - Digit 2: 7-4 - 7-6: YCORE - 5-4: CCORE - - Digit 1: 3-0 - 3: RANGE = 1 - 2: HACTEXT - 1: HSFMT - -0x47 is the sync byte for MPEG-2 transport stream packets. -Datasheet incorrectly states to use 47 decimal. 188 is the length. -All DVB compliant frontends output packets with this start code. - -Hauppauge WinTV cx88 IR information ------------------------------------ - -The controls for the mux are GPIO [0,1] for source, and GPIO 2 for muting. - -====== ======== ================================================= -GPIO0 GPIO1 -====== ======== ================================================= - 0 0 TV Audio - 1 0 FM radio - 0 1 Line-In - 1 1 Mono tuner bypass or CD passthru (tuner specific) -====== ======== ================================================= - -GPIO 16(I believe) is tied to the IR port (if present). - - -From the data sheet: - -- Register 24'h20004 PCI Interrupt Status - - - bit [18] IR_SMP_INT Set when 32 input samples have been collected over - - gpio[16] pin into GP_SAMPLE register. - -What's missing from the data sheet: - -- Setup 4KHz sampling rate (roughly 2x oversampled; good enough for our RC5 - compat remote) -- set register 0x35C050 to 0xa80a80 -- enable sampling -- set register 0x35C054 to 0x5 -- enable the IRQ bit 18 in the interrupt mask register (and - provide for a handler) - -GP_SAMPLE register is at 0x35C058 - -Bits are then right shifted into the GP_SAMPLE register at the specified -rate; you get an interrupt when a full DWORD is received. -You need to recover the actual RC5 bits out of the (oversampled) IR sensor -bits. (Hint: look for the 0/1and 1/0 crossings of the RC5 bi-phase data) An -actual raw RC5 code will span 2-3 DWORDS, depending on the actual alignment. - -I'm pretty sure when no IR signal is present the receiver is always in a -marking state(1); but stray light, etc can cause intermittent noise values -as well. Remember, this is a free running sample of the IR receiver state -over time, so don't assume any sample starts at any particular place. - -Additional info -~~~~~~~~~~~~~~~ - -This data sheet (google search) seems to have a lovely description of the -RC5 basics: -http://www.atmel.com/dyn/resources/prod_documents/doc2817.pdf - -This document has more data: -http://www.nenya.be/beor/electronics/rc5.htm - -This document has a how to decode a bi-phase data stream: -http://www.ee.washington.edu/circuit_archive/text/ir_decode.txt - -This document has still more info: -http://www.xs4all.nl/~sbp/knowledge/ir/rc5.htm diff --git a/Documentation/media/v4l-drivers/index.rst b/Documentation/media/v4l-drivers/index.rst index 52d7c8d14ee7..dfc878c050da 100644 --- a/Documentation/media/v4l-drivers/index.rst +++ b/Documentation/media/v4l-drivers/index.rst @@ -68,6 +68,7 @@ For more details see the file COPYING in the source distribution of Linux. bttv-devel cpia2_devel + cx88-devel vimc-devel meye-uapi |