1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-or-later
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * ImgTec IR Decoder setup for Philips RC-6 protocol.
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * Copyright 2012-2014 Imagination Technologies Ltd.
6*4882a593Smuzhiyun */
7*4882a593Smuzhiyun
8*4882a593Smuzhiyun #include "img-ir-hw.h"
9*4882a593Smuzhiyun
10*4882a593Smuzhiyun /* Convert RC6 data to a scancode */
img_ir_rc6_scancode(int len,u64 raw,u64 enabled_protocols,struct img_ir_scancode_req * request)11*4882a593Smuzhiyun static int img_ir_rc6_scancode(int len, u64 raw, u64 enabled_protocols,
12*4882a593Smuzhiyun struct img_ir_scancode_req *request)
13*4882a593Smuzhiyun {
14*4882a593Smuzhiyun unsigned int addr, cmd, mode, trl1, trl2;
15*4882a593Smuzhiyun
16*4882a593Smuzhiyun /*
17*4882a593Smuzhiyun * Due to a side effect of the decoder handling the double length
18*4882a593Smuzhiyun * Trailer bit, the header information is a bit scrambled, and the
19*4882a593Smuzhiyun * raw data is shifted incorrectly.
20*4882a593Smuzhiyun * This workaround effectively recovers the header bits.
21*4882a593Smuzhiyun *
22*4882a593Smuzhiyun * The Header field should look like this:
23*4882a593Smuzhiyun *
24*4882a593Smuzhiyun * StartBit ModeBit2 ModeBit1 ModeBit0 TrailerBit
25*4882a593Smuzhiyun *
26*4882a593Smuzhiyun * But what we get is:
27*4882a593Smuzhiyun *
28*4882a593Smuzhiyun * ModeBit2 ModeBit1 ModeBit0 TrailerBit1 TrailerBit2
29*4882a593Smuzhiyun *
30*4882a593Smuzhiyun * The start bit is not important to recover the scancode.
31*4882a593Smuzhiyun */
32*4882a593Smuzhiyun
33*4882a593Smuzhiyun raw >>= 27;
34*4882a593Smuzhiyun
35*4882a593Smuzhiyun trl1 = (raw >> 17) & 0x01;
36*4882a593Smuzhiyun trl2 = (raw >> 16) & 0x01;
37*4882a593Smuzhiyun
38*4882a593Smuzhiyun mode = (raw >> 18) & 0x07;
39*4882a593Smuzhiyun addr = (raw >> 8) & 0xff;
40*4882a593Smuzhiyun cmd = raw & 0xff;
41*4882a593Smuzhiyun
42*4882a593Smuzhiyun /*
43*4882a593Smuzhiyun * Due to the above explained irregularity the trailer bits cannot
44*4882a593Smuzhiyun * have the same value.
45*4882a593Smuzhiyun */
46*4882a593Smuzhiyun if (trl1 == trl2)
47*4882a593Smuzhiyun return -EINVAL;
48*4882a593Smuzhiyun
49*4882a593Smuzhiyun /* Only mode 0 supported for now */
50*4882a593Smuzhiyun if (mode)
51*4882a593Smuzhiyun return -EINVAL;
52*4882a593Smuzhiyun
53*4882a593Smuzhiyun request->protocol = RC_PROTO_RC6_0;
54*4882a593Smuzhiyun request->scancode = addr << 8 | cmd;
55*4882a593Smuzhiyun request->toggle = trl2;
56*4882a593Smuzhiyun return IMG_IR_SCANCODE;
57*4882a593Smuzhiyun }
58*4882a593Smuzhiyun
59*4882a593Smuzhiyun /* Convert RC6 scancode to RC6 data filter */
img_ir_rc6_filter(const struct rc_scancode_filter * in,struct img_ir_filter * out,u64 protocols)60*4882a593Smuzhiyun static int img_ir_rc6_filter(const struct rc_scancode_filter *in,
61*4882a593Smuzhiyun struct img_ir_filter *out, u64 protocols)
62*4882a593Smuzhiyun {
63*4882a593Smuzhiyun /* Not supported by the hw. */
64*4882a593Smuzhiyun return -EINVAL;
65*4882a593Smuzhiyun }
66*4882a593Smuzhiyun
67*4882a593Smuzhiyun /*
68*4882a593Smuzhiyun * RC-6 decoder
69*4882a593Smuzhiyun * see http://www.sbprojects.com/knowledge/ir/rc6.php
70*4882a593Smuzhiyun */
71*4882a593Smuzhiyun struct img_ir_decoder img_ir_rc6 = {
72*4882a593Smuzhiyun .type = RC_PROTO_BIT_RC6_0,
73*4882a593Smuzhiyun .control = {
74*4882a593Smuzhiyun .bitorien = 1,
75*4882a593Smuzhiyun .code_type = IMG_IR_CODETYPE_BIPHASE,
76*4882a593Smuzhiyun .decoden = 1,
77*4882a593Smuzhiyun .decodinpol = 1,
78*4882a593Smuzhiyun },
79*4882a593Smuzhiyun /* main timings */
80*4882a593Smuzhiyun .tolerance = 20,
81*4882a593Smuzhiyun /*
82*4882a593Smuzhiyun * Due to a quirk in the img-ir decoder, default header values do
83*4882a593Smuzhiyun * not work, the values described below were extracted from
84*4882a593Smuzhiyun * successful RTL test cases.
85*4882a593Smuzhiyun */
86*4882a593Smuzhiyun .timings = {
87*4882a593Smuzhiyun /* leader symbol */
88*4882a593Smuzhiyun .ldr = {
89*4882a593Smuzhiyun .pulse = { 650 },
90*4882a593Smuzhiyun .space = { 660 },
91*4882a593Smuzhiyun },
92*4882a593Smuzhiyun /* 0 symbol */
93*4882a593Smuzhiyun .s00 = {
94*4882a593Smuzhiyun .pulse = { 370 },
95*4882a593Smuzhiyun .space = { 370 },
96*4882a593Smuzhiyun },
97*4882a593Smuzhiyun /* 01 symbol */
98*4882a593Smuzhiyun .s01 = {
99*4882a593Smuzhiyun .pulse = { 370 },
100*4882a593Smuzhiyun .space = { 370 },
101*4882a593Smuzhiyun },
102*4882a593Smuzhiyun /* free time */
103*4882a593Smuzhiyun .ft = {
104*4882a593Smuzhiyun .minlen = 21,
105*4882a593Smuzhiyun .maxlen = 21,
106*4882a593Smuzhiyun .ft_min = 2666, /* 2.666 ms */
107*4882a593Smuzhiyun },
108*4882a593Smuzhiyun },
109*4882a593Smuzhiyun
110*4882a593Smuzhiyun /* scancode logic */
111*4882a593Smuzhiyun .scancode = img_ir_rc6_scancode,
112*4882a593Smuzhiyun .filter = img_ir_rc6_filter,
113*4882a593Smuzhiyun };
114