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