The Radiotrack radio driver | Linux 6.18.37

요약·해설과 원문, 전문 번역을 서로 분리했습니다. API 이름, symbol, source path는 원문 표기를 사용합니다.

1. 요약·해설

원문의 핵심 논리와 kernel programming 관점의 보충 설명입니다. 아래의 전문 번역과는 별도로 작성했습니다.

요약과 해설

radiotrack.rst:1-168

RadioTrack은 하나의 8-bit ISA I/O port로 volume, stereo detect, radio audio path와 tuner serial update를 동시에 제어합니다. Frequency는 24-bit code로 변환한 뒤 LSb부터 zero/one 두 phase를 전송합니다.

문서 구성

원문 줄내용

1-38실험 문서의 계보와 목적

39-52Card와 RF/VFO 한계

53-74I/O port bit layout

75-100Volume, stereo, audio path truth table

101-12324-bit tuning protocol

124-168Card, volume, stereo, frequency programming 예제

2. 영어 원문 전체

번역 기준이 된 Linux v6.18.37 원문입니다. 줄 번호는 이 버전의 파일 좌표입니다.

원문 전체 펼치기

1 .. SPDX-License-Identifier: GPL-2.0

3 The Radiotrack radio driver

4 ===========================

6 Author: Stephen M. Benoit <benoits@servicepro.com>

8 Date: Dec 14, 1996

10 ACKNOWLEDGMENTS

11 ----------------

13 This document was made based on 'C' code for Linux from Gideon le Grange

14 (legrang@active.co.za or legrang@cs.sun.ac.za) in 1994, and elaborations from

15 Frans Brinkman (brinkman@esd.nl) in 1996. The results reported here are from

16 experiments that the author performed on his own setup, so your mileage may

17 vary... I make no guarantees, claims or warranties to the suitability or

18 validity of this information. No other documentation on the AIMS

19 Lab (http://www.aimslab.com/) RadioTrack card was made available to the

20 author. This document is offered in the hopes that it might help users who

21 want to use the RadioTrack card in an environment other than MS Windows.

23 WHY THIS DOCUMENT?

24 ------------------

26 I have a RadioTrack card from back when I ran an MS-Windows platform. After

27 converting to Linux, I found Gideon le Grange's command-line software for

28 running the card, and found that it was good! Frans Brinkman made a

29 comfortable X-windows interface, and added a scanning feature. For hack

30 value, I wanted to see if the tuner could be tuned beyond the usual FM radio

31 broadcast band, so I could pick up the audio carriers from North American

32 broadcast TV channels, situated just below and above the 87.0-109.0 MHz range.

33 I did not get much success, but I learned about programming ioports under

34 Linux and gained some insights about the hardware design used for the card.

36 So, without further delay, here are the details.

39 PHYSICAL DESCRIPTION

40 --------------------

42 The RadioTrack card is an ISA 8-bit FM radio card. The radio frequency (RF)

43 input is simply an antenna lead, and the output is a power audio signal

44 available through a miniature phone plug. Its RF frequencies of operation are

45 more or less limited from 87.0 to 109.0 MHz (the commercial FM broadcast

46 band). Although the registers can be programmed to request frequencies beyond

47 these limits, experiments did not give promising results. The variable

48 frequency oscillator (VFO) that demodulates the intermediate frequency (IF)

49 signal probably has a small range of useful frequencies, and wraps around or

50 gets clipped beyond the limits mentioned above.

53 CONTROLLING THE CARD WITH IOPORT

54 --------------------------------

56 The RadioTrack (base) ioport is configurable for 0x30c or 0x20c. Only one

57 ioport seems to be involved. The ioport decoding circuitry must be pretty

58 simple, as individual ioport bits are directly matched to specific functions

59 (or blocks) of the radio card. This way, many functions can be changed in

60 parallel with one write to the ioport. The only feedback available through

61 the ioports appears to be the "Stereo Detect" bit.

63 The bits of the ioport are arranged as follows:

65 .. code-block:: none

67 MSb LSb

68 +------+------+------+--------+--------+-------+---------+--------+

70 | (+) | (-) | | Detect | Audio | (bit) | (latch) | Update |

72 +------+------+------+--------+--------+-------+---------+--------+

75 ==== ==== =================================

76 VolA VolB Description

77 ==== ==== =================================

78 0 0 audio mute

79 0 1 volume + (some delay required)

80 1 0 volume - (some delay required)

81 1 1 stay at present volume

82 ==== ==== =================================

84 ==================== ===========

85 Stereo Detect Enable Description

86 ==================== ===========

87 0 No Detect

88 1 Detect

89 ==================== ===========

91 Results available by reading ioport >60 msec after last port write.

93 0xff ==> no stereo detected, 0xfd ==> stereo detected.

95 ============================= =============================

96 Radio to Audio (path) Enable Description

97 ============================= =============================

98 0 Disable path (silence)

99 1 Enable path (audio produced)

100 ============================= =============================

101

102 ===== ===== ==================

103 TuneA TuneB Description

104 ===== ===== ==================

105 0 0 "zero" bit phase 1

106 0 1 "zero" bit phase 2

107 1 0 "one" bit phase 1

108 1 1 "one" bit phase 2

109 ===== ===== ==================

110

111

112 24-bit code, where bits = (freq*40) + 10486188.

113 The Most Significant 11 bits must be 1010 xxxx 0x0 to be valid.

114 The bits are shifted in LSb first.

115

116 ================== ===========================

117 Tune Update Enable Description

118 ================== ===========================

119 0 Tuner held constant

120 1 Tuner updating in progress

121 ================== ===========================

122

123

124 PROGRAMMING EXAMPLES

125 --------------------

126

127 .. code-block:: none

128

129 Default: BASE <-- 0xc8 (current volume, no stereo detect,

130 radio enable, tuner adjust disable)

131

132 Card Off: BASE <-- 0x00 (audio mute, no stereo detect,

133 radio disable, tuner adjust disable)

134

135 Card On: BASE <-- 0x00 (see "Card Off", clears any unfinished business)

136 BASE <-- 0xc8 (see "Default")

137

138 Volume Down: BASE <-- 0x48 (volume down, no stereo detect,

139 radio enable, tuner adjust disable)

140 wait 10 msec

141 BASE <-- 0xc8 (see "Default")

142

143 Volume Up: BASE <-- 0x88 (volume up, no stereo detect,

144 radio enable, tuner adjust disable)

145 wait 10 msec

146 BASE <-- 0xc8 (see "Default")

147

148 Check Stereo: BASE <-- 0xd8 (current volume, stereo detect,

149 radio enable, tuner adjust disable)

150 wait 100 msec

151 x <-- BASE (read ioport)

152 BASE <-- 0xc8 (see "Default")

153

154 x=0xff ==> "not stereo", x=0xfd ==> "stereo detected"

155

156 Set Frequency: code = (freq*40) + 10486188

157 foreach of the 24 bits in code,

158 (from Least to Most Significant):

159 to write a "zero" bit,

160 BASE <-- 0x01 (audio mute, no stereo detect, radio

161 disable, "zero" bit phase 1, tuner adjust)

162 BASE <-- 0x03 (audio mute, no stereo detect, radio

163 disable, "zero" bit phase 2, tuner adjust)

164 to write a "one" bit,

165 BASE <-- 0x05 (audio mute, no stereo detect, radio

166 disable, "one" bit phase 1, tuner adjust)

167 BASE <-- 0x07 (audio mute, no stereo detect, radio

168 disable, "one" bit phase 2, tuner adjust)

169

3. 한국어 전문 번역

영어 원문의 문단 순서와 의미를 유지한 전체 번역입니다. 코드, 함수명, symbol과 URL은 원문 표기를 유지합니다.

문서의 출처와 주의사항

1-22

Stephen M. Benoit가 1996년 12월 14일 작성한 이 `GPL-2.0` 문서는 AIMS Lab RadioTrack radio card의 제어 방법을 설명합니다.

문서는 Gideon le Grange가 1994년에 작성한 Linux용 C code와 Frans Brinkman이 1996년에 더한 설명을 토대로 합니다. 보고된 결과는 저자 자신의 장비에서 수행한 실험이므로 다른 환경에서는 다를 수 있으며, 정보의 적합성이나 유효성을 보증하지 않습니다.

저자는 AIMS Lab(`http://www.aimslab.com/`) RadioTrack card에 관한 다른 문서를 구할 수 없었습니다. 이 자료는 MS Windows 이외의 환경에서 card를 사용하려는 사람에게 도움이 되길 바라며 제공됐습니다.

문서 계보

연도기여자기여

1994Gideon le GrangeLinux C control code

1996Frans Brinkman설명 보강

1996-12-14Stephen M. Benoit실험 기반 hardware/programming 문서

주의환경 의존실험 결과에 대한 보증 없음

.. SPDX-License-Identifier: GPL-2.0

The Radiotrack radio driver
===========================

Author: Stephen M. Benoit <benoits@servicepro.com>

Date:  Dec 14, 1996

ACKNOWLEDGMENTS
----------------

This document was made based on 'C' code for Linux from Gideon le Grange
(legrang@active.co.za or legrang@cs.sun.ac.za) in 1994, and elaborations from
Frans Brinkman (brinkman@esd.nl) in 1996.  The results reported here are from
experiments that the author performed on his own setup, so your mileage may
vary... I make no guarantees, claims or warranties to the suitability or
validity of this information.  No other documentation on the AIMS
Lab (http://www.aimslab.com/) RadioTrack card was made available to the
author.  This document is offered in the hopes that it might help users who
want to use the RadioTrack card in an environment other than MS Windows.

이 문서를 작성한 이유

23-38

저자는 MS Windows를 사용하던 시절의 RadioTrack card를 Linux로 전환한 뒤 Gideon le Grange의 command-line software를 발견했습니다. Frans Brinkman은 편리한 X Windows interface와 scanning 기능을 추가했습니다.

저자는 일반 FM broadcast band를 넘어 tuner를 조정해 87.0-109.0 MHz 범위 바로 아래와 위에 있는 북미 broadcast TV channel의 audio carrier를 수신할 수 있는지 시험했습니다. 큰 성공은 없었지만 Linux I/O port programming과 card hardware 설계에 관한 통찰을 얻었고, 그 세부 사항을 이 문서에 기록했습니다.

실험 목표와 결과

항목내용

기존 도구Command-line control과 X Windows scanning UI

실험 목표FM band 밖의 TV audio carrier 수신

대상 범위87.0-109.0 MHz 주변

결과수신 성공은 제한적

성과Linux ioport programming과 hardware 이해

WHY THIS DOCUMENT?
------------------

I have a RadioTrack card from back when I ran an MS-Windows platform.  After
converting to Linux, I found Gideon le Grange's command-line software for
running the card, and found that it was good!  Frans Brinkman made a
comfortable X-windows interface, and added a scanning feature.  For hack
value, I wanted to see if the tuner could be tuned beyond the usual FM radio
broadcast band, so I could pick up the audio carriers from North American
broadcast TV channels, situated just below and above the 87.0-109.0 MHz range.
I did not get much success, but I learned about programming ioports under
Linux and gained some insights about the hardware design used for the card.

So, without further delay, here are the details.

Card의 물리적 특성

39-52

RadioTrack은 ISA 8-bit FM radio card입니다. RF input은 단순한 antenna lead이고, output은 miniature phone plug에서 나오는 power audio signal입니다.

실용 RF 동작 범위는 대략 commercial FM band인 87.0-109.0 MHz로 제한됩니다. Register에는 범위 밖 frequency도 요청할 수 있지만 실험 결과는 좋지 않았습니다. IF signal을 demodulate하는 variable frequency oscillator(VFO)의 유효 범위가 좁아 한계를 넘으면 wraparound되거나 clipping되는 것으로 추정됩니다.

RadioTrack hardware 특성

항목값 또는 설명

BusISA 8-bit

RF inputAntenna lead

Audio outputMiniature phone plug의 power audio

실용 주파수약 87.0-109.0 MHz

범위 밖 동작Register 요청 가능, 실제 결과는 불안정

추정 제한VFO range와 wraparound/clipping

PHYSICAL DESCRIPTION
--------------------

The RadioTrack card is an ISA 8-bit FM radio card.  The radio frequency (RF)
input is simply an antenna lead, and the output is a power audio signal
available through a miniature phone plug.  Its RF frequencies of operation are
more or less limited from 87.0 to 109.0 MHz (the commercial FM broadcast
band).  Although the registers can be programmed to request frequencies beyond
these limits, experiments did not give promising results.  The variable
frequency oscillator (VFO) that demodulates the intermediate frequency (IF)
signal probably has a small range of useful frequencies, and wraps around or
gets clipped beyond the limits mentioned above.

I/O port와 bit 배치

53-74

RadioTrack base I/O port는 `0x30c` 또는 `0x20c`로 설정할 수 있으며, 관찰상 하나의 port만 사용합니다. Decode 회로가 단순해 개별 port bit가 card의 특정 function이나 block에 직접 대응합니다. 따라서 한 번의 port write로 여러 기능을 병렬 변경할 수 있습니다.

I/O port에서 읽을 수 있는 feedback은 `Stereo Detect` bit뿐인 것으로 보입니다. 8개 bit는 MSb에서 LSb 순서로 `VolA`, `VolB`, unknown, `Stereo Detect Enable`, `Radio Audio Enable`, `TuneA`, `TuneB`, `Tune Update Enable`입니다.

8-bit I/O port layout

BitMSb→LSb field기능

7`VolA`Volume control (+ side)

6`VolB`Volume control (- side)

5`????`Unknown

4`Stereo Detect Enable`Stereo detect gate

3`Radio Audio Enable`Radio-to-audio path

2`TuneA`Serial tune data bit phase

1`TuneB`Serial tune latch phase

0`Tune Update Enable`Tuner update gate

원문의 MSb→LSb ASCII register를 bit 좌표로 재구성했습니다.

한 번의 I/O write

Write BASE byteVolume bitsStereo detect gateAudio pathTune phaseUpdate gate

Read BASE after delayStereo Detect feedback

각 bit가 독립 function에 직접 연결돼 여러 card 상태를 동시에 바꿉니다.

CONTROLLING THE CARD WITH IOPORT
--------------------------------

The RadioTrack (base) ioport is configurable for 0x30c or 0x20c.  Only one
ioport seems to be involved.  The ioport decoding circuitry must be pretty
simple, as individual ioport bits are directly matched to specific functions
(or blocks) of the radio card.  This way, many functions can be changed in
parallel with one write to the ioport.  The only feedback available through
the ioports appears to be the "Stereo Detect" bit.

The bits of the ioport are arranged as follows:

.. code-block:: none

        MSb                                                         LSb
        +------+------+------+--------+--------+-------+---------+--------+
        | VolA | VolB | ???? | Stereo | Radio  | TuneA | TuneB   | Tune   |
        |  (+) |  (-) |      | Detect | Audio  | (bit) | (latch) | Update |
        |      |      |      | Enable | Enable |       |         | Enable |
        +------+------+------+--------+--------+-------+---------+--------+

Volume, stereo detect와 audio path

75-100

`VolA/VolB`가 `00`이면 audio mute, `01`이면 volume up, `10`이면 volume down, `11`이면 현재 volume을 유지합니다. Volume up/down pulse 뒤에는 일정한 delay가 필요합니다.

`Stereo Detect Enable`이 0이면 detect하지 않고 1이면 detect합니다. 마지막 port write 후 60 ms보다 늦게 I/O port를 읽어야 결과를 얻을 수 있습니다. `0xff`는 stereo 미검출, `0xfd`는 stereo 검출을 뜻합니다.

`Radio Audio Enable`이 0이면 radio-to-audio path를 disable해 silence가 되고, 1이면 path를 enable해 audio가 출력됩니다.

VolA / VolB truth table

VolAVolB동작

00Audio mute

01Volume +, delay 필요

10Volume -, delay 필요

11현재 volume 유지

Stereo detect

Enable동작Read result

0No Detect의미 있는 feedback 없음

1Detect`>60 ms` 뒤 `0xff`: no stereo, `0xfd`: stereo

Radio-to-audio path

Enable결과

0Path disable, silence

1Path enable, audio produced

====  ====  =================================
VolA  VolB  Description
====  ====  =================================
0         0  audio mute
0         1  volume +    (some delay required)
1         0  volume -    (some delay required)
1         1  stay at present volume
====  ====  =================================

====================        ===========
Stereo Detect Enable        Description
====================        ===========
0                        No Detect
1                        Detect
====================        ===========

Results available by reading ioport >60 msec after last port write.

  0xff ==> no stereo detected,  0xfd ==> stereo detected.

=============================        =============================
Radio to Audio (path) Enable        Description
=============================        =============================
0                                Disable path (silence)
1                                Enable path  (audio produced)
=============================        =============================

Tune bit protocol과 24-bit code

101-123

`TuneA/TuneB`의 두 phase로 serial bit를 기록합니다. `00`과 `01`은 각각 zero bit phase 1과 phase 2, `10`과 `11`은 one bit phase 1과 phase 2입니다.

Tuner에 보내는 값은 `code = (freq * 40) + 10486188`로 계산한 24-bit code입니다. 유효하려면 가장 중요한 11 bit가 `1010 xxxx 0x0` 형태여야 하며, bit는 LSb부터 먼저 shift합니다.

`Tune Update Enable`이 0이면 tuner 값을 고정하고, 1이면 tuner update가 진행 중임을 뜻합니다.

TuneA / TuneB phase table

TuneATuneBSerial 의미

00Zero bit phase 1

01Zero bit phase 2

10One bit phase 1

11One bit phase 2

Frequency code programming

Frequency(freq * 40) + 1048618824-bit code

Validate upper 11 bits1010 xxxx 0x0

Shift LSb firstWrite phase 1Write phase 2Repeat 24 bits

Tune Update Enable = 0Hold tuner constant

Tune Update Enable = 1Tuner update in progress

24-bit code를 계산한 뒤 LSb부터 각 bit의 두 phase를 전송합니다.


=====  =====  ==================
TuneA  TuneB  Description
=====  =====  ==================
0        0     "zero" bit phase 1
0        1     "zero" bit phase 2
1        0     "one" bit phase 1
1        1     "one" bit phase 2
=====  =====  ==================


24-bit code, where bits = (freq*40) + 10486188.
The Most Significant 11 bits must be 1010 xxxx 0x0 to be valid.
The bits are shifted in LSb first.

==================        ===========================
Tune Update Enable        Description
==================        ===========================
0                        Tuner held constant
1                        Tuner updating in progress
==================        ===========================

I/O programming 예제

124-168

Default 상태는 `BASE ← 0xc8`입니다. 현재 volume을 유지하고 stereo detect를 끄며 radio audio를 enable하고 tuner adjustment를 disable합니다. Card off는 `BASE ← 0x00`으로 audio mute, detect off, radio disable, tuner adjustment disable을 설정합니다. Card on은 먼저 `0x00`으로 미완료 상태를 지운 뒤 `0xc8` default를 기록합니다.

Volume down은 `BASE ← 0x48`, 10 ms 대기, `BASE ← 0xc8` 순서입니다. Volume up은 `BASE ← 0x88`, 10 ms 대기, `BASE ← 0xc8` 순서입니다.

Stereo 확인은 `BASE ← 0xd8`로 detect를 enable하고 100 ms 기다린 뒤 `x ← BASE`로 읽고 `BASE ← 0xc8`로 복구합니다. `x=0xff`면 not stereo, `x=0xfd`면 stereo detected입니다.

Frequency 설정은 먼저 `code = (freq * 40) + 10486188`을 계산합니다. 24개 bit를 LSb부터 처리하면서 zero bit는 `0x01`과 `0x03`, one bit는 `0x05`와 `0x07`의 두 phase write로 전송합니다. 이 write들은 audio mute, stereo detect off, radio disable 상태에서 tuner adjustment를 enable합니다.

Programming command 요약

작업Write/read sequenceDelay/result

Default`BASE ← 0xc8`현재 volume, radio enabled

Card Off`BASE ← 0x00`Mute, radio disabled

Card On`0x00 → 0xc8`미완료 상태 clear 후 default

Volume Down`0x48 → 0xc8`중간 10 ms

Volume Up`0x88 → 0xc8`중간 10 ms

Check Stereo`0xd8 → read BASE → 0xc8`100 ms, `ff` no / `fd` yes

Write zero`0x01 → 0x03`Phase 1 → phase 2

Write one`0x05 → 0x07`Phase 1 → phase 2

24-bit frequency write loop

Compute codeSelect current LSb

Bit = 0BASE 0x01BASE 0x03

Bit = 1BASE 0x05BASE 0x07

Advance to next bitRepeat until 24 bits written

각 bit를 LSb에서 MSb 방향으로 두 phase씩 기록합니다.

PROGRAMMING EXAMPLES
--------------------

.. code-block:: none

        Default:        BASE <-- 0xc8  (current volume, no stereo detect,
                                        radio enable, tuner adjust disable)

        Card Off:        BASE <-- 0x00  (audio mute, no stereo detect,
                                        radio disable, tuner adjust disable)

        Card On:        BASE <-- 0x00  (see "Card Off", clears any unfinished business)
                        BASE <-- 0xc8  (see "Default")

        Volume Down:    BASE <-- 0x48  (volume down, no stereo detect,
                                        radio enable, tuner adjust disable)
                        wait 10 msec
                        BASE <-- 0xc8  (see "Default")

        Volume Up:      BASE <-- 0x88  (volume up, no stereo detect,
                                        radio enable, tuner adjust disable)
                        wait 10 msec
                        BASE <-- 0xc8  (see "Default")

        Check Stereo:   BASE <-- 0xd8  (current volume, stereo detect,
                                        radio enable, tuner adjust disable)
                        wait 100 msec
                        x <-- BASE     (read ioport)
                        BASE <-- 0xc8  (see "Default")

                        x=0xff ==> "not stereo", x=0xfd ==> "stereo detected"

        Set Frequency:  code = (freq*40) + 10486188
                        foreach of the 24 bits in code,
                        (from Least to Most Significant):
                        to write a "zero" bit,
                        BASE <-- 0x01  (audio mute, no stereo detect, radio
                                        disable, "zero" bit phase 1, tuner adjust)
                        BASE <-- 0x03  (audio mute, no stereo detect, radio
                                        disable, "zero" bit phase 2, tuner adjust)
                        to write a "one" bit,
                        BASE <-- 0x05  (audio mute, no stereo detect, radio
                                        disable, "one" bit phase 1, tuner adjust)
                        BASE <-- 0x07  (audio mute, no stereo detect, radio
                                        disable, "one" bit phase 2, tuner adjust)