Based on kernel version 5.7.10
. Page generated on 2020-07-23 22:17 EST
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 | .. SPDX-License-Identifier: GPL-2.0 The cx88 driver =============== Author: Gerd Hoffmann This is a v4l2 device driver for the cx2388x chip. Current status -------------- video - Works. - Overlay isn't supported. audio - Works. The TV standard detection is made by the driver, as the hardware has bugs to auto-detect. - audio data dma (i.e. recording without loopback cable to the sound card) is supported via cx88-alsa. vbi - Works. How to add support for new cards -------------------------------- The driver needs some config info for the TV cards. This stuff is in cx88-cards.c. If the driver doesn't work well you likely need a new entry for your card in that file. Check the kernel log (using dmesg) to see whenever the driver knows your card or not. There is a line like this one: .. code-block:: none cx8800[0]: subsystem: 0070:3400, board: Hauppauge WinTV \ 34xxx models [card=1,autodetected] If your card is listed as "board: UNKNOWN/GENERIC" it is unknown to the driver. What to do then? 1) Try upgrading to the latest snapshot, maybe it has been added meanwhile. 2) You can try to create a new entry yourself, have a look at cx88-cards.c. If that worked, mail me your changes as unified diff ("diff -u"). 3) Or you can mail me the config information. We need at least the following information to add the card: - the PCI Subsystem ID ("0070:3400" from the line above, "lspci -v" output is fine too). - the tuner type used by the card. You can try to find one by 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 |