1 .. SPDX-License-Identifier: GPL-2.0 1 .. SPDX-License-Identifier: GPL-2.0
2 2
3 The cx88 driver 3 The cx88 driver
4 =============== 4 ===============
5 5
6 Author: Gerd Hoffmann 6 Author: Gerd Hoffmann
7 7
8 Documentation missing at the cx88 datasheet 8 Documentation missing at the cx88 datasheet
9 ------------------------------------------- 9 -------------------------------------------
10 10
11 MO_OUTPUT_FORMAT (0x310164) 11 MO_OUTPUT_FORMAT (0x310164)
12 12
13 .. code-block:: none 13 .. code-block:: none
14 14
15 Previous default from DScaler: 0x1c1f0008 15 Previous default from DScaler: 0x1c1f0008
16 Digit 8: 31-28 16 Digit 8: 31-28
17 28: PREVREMOD = 1 17 28: PREVREMOD = 1
18 18
19 Digit 7: 27-24 (0xc = 12 = b1100 ) 19 Digit 7: 27-24 (0xc = 12 = b1100 )
20 27: COMBALT = 1 20 27: COMBALT = 1
21 26: PAL_INV_PHASE 21 26: PAL_INV_PHASE
22 (DScaler apparently set this to 1, resulte 22 (DScaler apparently set this to 1, resulted in sucky picture)
23 23
24 Digits 6,5: 23-16 24 Digits 6,5: 23-16
25 25-16: COMB_RANGE = 0x1f [default] (9 bits - 25 25-16: COMB_RANGE = 0x1f [default] (9 bits -> max 512)
26 26
27 Digit 4: 15-12 27 Digit 4: 15-12
28 15: DISIFX = 0 28 15: DISIFX = 0
29 14: INVCBF = 0 29 14: INVCBF = 0
30 13: DISADAPT = 0 30 13: DISADAPT = 0
31 12: NARROWADAPT = 0 31 12: NARROWADAPT = 0
32 32
33 Digit 3: 11-8 33 Digit 3: 11-8
34 11: FORCE2H 34 11: FORCE2H
35 10: FORCEREMD 35 10: FORCEREMD
36 9: NCHROMAEN 36 9: NCHROMAEN
37 8: NREMODEN 37 8: NREMODEN
38 38
39 Digit 2: 7-4 39 Digit 2: 7-4
40 7-6: YCORE 40 7-6: YCORE
41 5-4: CCORE 41 5-4: CCORE
42 42
43 Digit 1: 3-0 43 Digit 1: 3-0
44 3: RANGE = 1 44 3: RANGE = 1
45 2: HACTEXT 45 2: HACTEXT
46 1: HSFMT 46 1: HSFMT
47 47
48 0x47 is the sync byte for MPEG-2 transport str 48 0x47 is the sync byte for MPEG-2 transport stream packets.
49 Datasheet incorrectly states to use 47 decimal 49 Datasheet incorrectly states to use 47 decimal. 188 is the length.
50 All DVB compliant frontends output packets wit 50 All DVB compliant frontends output packets with this start code.
51 51
52 Hauppauge WinTV cx88 IR information 52 Hauppauge WinTV cx88 IR information
53 ----------------------------------- 53 -----------------------------------
54 54
55 The controls for the mux are GPIO [0,1] for so 55 The controls for the mux are GPIO [0,1] for source, and GPIO 2 for muting.
56 56
57 ====== ======== ============================== 57 ====== ======== =================================================
58 GPIO0 GPIO1 58 GPIO0 GPIO1
59 ====== ======== ============================== 59 ====== ======== =================================================
60 0 0 TV Audio 60 0 0 TV Audio
61 1 0 FM radio 61 1 0 FM radio
62 0 1 Line-In 62 0 1 Line-In
63 1 1 Mono tuner bypass or CD passth 63 1 1 Mono tuner bypass or CD passthru (tuner specific)
64 ====== ======== ============================== 64 ====== ======== =================================================
65 65
66 GPIO 16(I believe) is tied to the IR port (if 66 GPIO 16(I believe) is tied to the IR port (if present).
67 67
68 68
69 From the data sheet: 69 From the data sheet:
70 70
71 - Register 24'h20004 PCI Interrupt Status 71 - Register 24'h20004 PCI Interrupt Status
72 72
73 - bit [18] IR_SMP_INT Set when 32 input samp 73 - bit [18] IR_SMP_INT Set when 32 input samples have been collected over
74 - gpio[16] pin into GP_SAMPLE register. 74 - gpio[16] pin into GP_SAMPLE register.
75 75
76 What's missing from the data sheet: 76 What's missing from the data sheet:
77 77
78 - Setup 4KHz sampling rate (roughly 2x oversam 78 - Setup 4KHz sampling rate (roughly 2x oversampled; good enough for our RC5
79 compat remote) 79 compat remote)
80 - set register 0x35C050 to 0xa80a80 80 - set register 0x35C050 to 0xa80a80
81 - enable sampling 81 - enable sampling
82 - set register 0x35C054 to 0x5 82 - set register 0x35C054 to 0x5
83 - enable the IRQ bit 18 in the interrupt mask 83 - enable the IRQ bit 18 in the interrupt mask register (and
84 provide for a handler) 84 provide for a handler)
85 85
86 GP_SAMPLE register is at 0x35C058 86 GP_SAMPLE register is at 0x35C058
87 87
88 Bits are then right shifted into the GP_SAMPLE 88 Bits are then right shifted into the GP_SAMPLE register at the specified
89 rate; you get an interrupt when a full DWORD i 89 rate; you get an interrupt when a full DWORD is received.
90 You need to recover the actual RC5 bits out of 90 You need to recover the actual RC5 bits out of the (oversampled) IR sensor
91 bits. (Hint: look for the 0/1and 1/0 crossings 91 bits. (Hint: look for the 0/1and 1/0 crossings of the RC5 bi-phase data) An
92 actual raw RC5 code will span 2-3 DWORDS, depe 92 actual raw RC5 code will span 2-3 DWORDS, depending on the actual alignment.
93 93
94 I'm pretty sure when no IR signal is present t 94 I'm pretty sure when no IR signal is present the receiver is always in a
95 marking state(1); but stray light, etc can cau 95 marking state(1); but stray light, etc can cause intermittent noise values
96 as well. Remember, this is a free running sam 96 as well. Remember, this is a free running sample of the IR receiver state
97 over time, so don't assume any sample starts a 97 over time, so don't assume any sample starts at any particular place.
98 98
99 Additional info 99 Additional info
100 ~~~~~~~~~~~~~~~ 100 ~~~~~~~~~~~~~~~
101 101
102 This data sheet (google search) seems to have 102 This data sheet (google search) seems to have a lovely description of the
103 RC5 basics: 103 RC5 basics:
104 http://www.atmel.com/dyn/resources/prod_docume 104 http://www.atmel.com/dyn/resources/prod_documents/doc2817.pdf
105 105
106 This document has more data: 106 This document has more data:
107 http://www.nenya.be/beor/electronics/rc5.htm 107 http://www.nenya.be/beor/electronics/rc5.htm
108 108
109 This document has a how to decode a bi-phase 109 This document has a how to decode a bi-phase data stream:
110 http://www.ee.washington.edu/circuit_archive/t 110 http://www.ee.washington.edu/circuit_archive/text/ir_decode.txt
111 111
112 This document has still more info: 112 This document has still more info:
113 http://www.xs4all.nl/~sbp/knowledge/ir/rc5.htm 113 http://www.xs4all.nl/~sbp/knowledge/ir/rc5.htm
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