Generic backlight scale and ambient-light sysfs ABI | 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.

Brightness scale and ambient sensor

sysfs-class-backlight:1-47

사람의 logarithmic brightness 지각에 맞춘 scale mapping과 ADP8860·ADP8870 sensor conversion 값을 정의합니다.

Ambient zone selection

sysfs-class-backlight:49-86

ADP8860·ADP8870의 ambient zone 번호, 0 mA off와 automatic operation 복귀·활성화 절차를 제공합니다.

Zone maximum and dim brightness

sysfs-class-backlight:88-185

ADP5520·ADP5501·ADP8860·ADP8870의 zone별 max·dim brightness 범위와 정확한 sysfs entry를 정리합니다.

2. 영어 원문 전체

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

원문 전체 펼치기

1 What: /sys/class/backlight/<backlight>/scale

2 Date: July 2019

3 KernelVersion: 5.4

4 Contact: Daniel Thompson <daniel.thompson@linaro.org>

5 Description:

6 Description of the scale of the brightness curve.

8 The human eye senses brightness approximately logarithmically,

9 hence linear changes in brightness are perceived as being

10 non-linear. To achieve a linear perception of brightness changes

11 controls like sliders need to apply a logarithmic mapping for

12 backlights with a linear brightness curve.

14 Possible values of the attribute are:

16 unknown

17 The scale of the brightness curve is unknown.

19 linear

20 The brightness changes linearly with each step. Brightness

21 controls should apply a logarithmic mapping for a linear

22 perception.

24 non-linear

25 The brightness changes non-linearly with each step. Brightness

26 controls should use a linear mapping for a linear perception.

28 What: /sys/class/backlight/<backlight>/ambient_light_level

29 Date: Apr, 2010

30 KernelVersion: v2.6.35

31 Contact: Michael Hennerich <michael.hennerich@analog.com>

32 Description:

33 (RO) Get conversion value of the light sensor.

35 The value is automatically updated every 80 ms when the

36 light sensor is enabled.

38 The value range is device-driver specific:

40 For ADP8870:

42 It returns integer between 0 (dark) and 8000 (max ambient

43 brightness).

45 For ADP8860:

47 It returns a 13-bits integer.

49 What: /sys/class/backlight/<backlight>/ambient_light_zone

50 Date: Apr, 2010

51 KernelVersion: v2.6.35

52 Contact: Michael Hennerich <michael.hennerich@analog.com>,

53 device-drivers-devel@blackfin.uclinux.org

55 Description:

56 (RW) Read or write the specific brightness level at which the

57 backlight operates.

59 The value meaning is device-driver specific:

61 For ADP8860:

63 == ==========================

64 0 Off: Backlight set to 0 mA

65 1 Level 1: daylight

66 2 Level 2: bright

67 3 Level 3: dark

68 == ==========================

70 For ADP8870:

72 == ==========================

73 0 Off: Backlight set to 0 mA

74 1 Level 1: daylight

75 2 Level 2: bright

76 3 Level 3: office

77 4 Level 4: indoor

78 5 Level 5: dark

79 == ==========================

81 Writing 0 returns to normal/automatic ambient light level

82 operation.

84 It can be enabled by writing the value stored in

85 /sys/class/backlight/<backlight>/max_brightness to

86 /sys/class/backlight/<backlight>/brightness.

88 What: /sys/class/backlight/<backlight>/<ambient light zone>_max

89 Date: Sep, 2009

90 KernelVersion: v2.6.32

91 Contact: device-drivers-devel@blackfin.uclinux.org

92 Description:

93 Control the maximum brightness for <ambient light zone>

94 on this <backlight>. Values are between 0 and 127. This file

95 will also show the brightness level stored for this

96 <ambient light zone>.

98 The <ambient light zone> is device-driver specific:

100 For ADP5520 and ADP5501, <ambient light zone> can be:

101

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

103 Ambient sysfs entry

104 light zone

105 =========== ================================================

106 daylight /sys/class/backlight/<backlight>/daylight_max

107 office /sys/class/backlight/<backlight>/office_max

108 dark /sys/class/backlight/<backlight>/dark_max

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

110

111 For ADP8860, <ambient light zone> can be:

112

113 =========== ================================================

114 Ambient sysfs entry

115 light zone

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

117 l1_daylight /sys/class/backlight/<backlight>/l1_daylight_max

118 l2_office /sys/class/backlight/<backlight>/l2_office_max

119 l3_dark /sys/class/backlight/<backlight>/l3_dark_max

120 =========== ================================================

121

122 For ADP8870, <ambient light zone> can be:

123

124 =========== ================================================

125 Ambient sysfs entry

126 light zone

127 =========== ================================================

128 l1_daylight /sys/class/backlight/<backlight>/l1_daylight_max

129 l2_bright /sys/class/backlight/<backlight>/l2_bright_max

130 l3_office /sys/class/backlight/<backlight>/l3_office_max

131 l4_indoor /sys/class/backlight/<backlight>/l4_indoor_max

132 l5_dark /sys/class/backlight/<backlight>/l5_dark_max

133 =========== ================================================

134

135 See also: /sys/class/backlight/<backlight>/ambient_light_zone.

136

137 What: /sys/class/backlight/<backlight>/<ambient light zone>_dim

138 Date: Sep, 2009

139 KernelVersion: v2.6.32

140 Contact: device-drivers-devel@blackfin.uclinux.org

141 Description:

142 Control the dim brightness for <ambient light zone>

143 on this <backlight>. Values are between 0 and 127, typically

144 set to 0. Full off when the backlight is disabled.

145 This file will also show the dim brightness level stored for

146 this <ambient light zone>.

147

148 The <ambient light zone> is device-driver specific:

149

150 For ADP5520 and ADP5501, <ambient light zone> can be:

151

152 =========== ================================================

153 Ambient sysfs entry

154 light zone

155 =========== ================================================

156 daylight /sys/class/backlight/<backlight>/daylight_dim

157 office /sys/class/backlight/<backlight>/office_dim

158 dark /sys/class/backlight/<backlight>/dark_dim

159 =========== ================================================

160

161 For ADP8860, <ambient light zone> can be:

162

163 =========== ================================================

164 Ambient sysfs entry

165 light zone

166 =========== ================================================

167 l1_daylight /sys/class/backlight/<backlight>/l1_daylight_dim

168 l2_office /sys/class/backlight/<backlight>/l2_office_dim

169 l3_dark /sys/class/backlight/<backlight>/l3_dark_dim

170 =========== ================================================

171

172 For ADP8870, <ambient light zone> can be:

173

174 =========== ================================================

175 Ambient sysfs entry

176 light zone

177 =========== ================================================

178 l1_daylight /sys/class/backlight/<backlight>/l1_daylight_dim

179 l2_bright /sys/class/backlight/<backlight>/l2_bright_dim

180 l3_office /sys/class/backlight/<backlight>/l3_office_dim

181 l4_indoor /sys/class/backlight/<backlight>/l4_indoor_dim

182 l5_dark /sys/class/backlight/<backlight>/l5_dark_dim

183 =========== ================================================

184

185 See also: /sys/class/backlight/<backlight>/ambient_light_zone.

186

187

3. 한국어 전문 번역

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

Brightness curve scale

1-26

항목	한국어 전문 번역
What	/sys/class/backlight/<backlight>/scale
Date	2019년 7월
KernelVersion	5.4
Contact	Daniel Thompson <daniel.thompson@linaro.org>
Description	Brightness curve의 scale을 설명합니다. 사람의 눈은 brightness를 대략 logarithmic하게 감지하므로 brightness의 linear change는 non-linear하게 인식됩니다. Linear brightness curve를 가진 backlight에서 brightness 변화가 linear하게 느껴지게 하려면 slider 같은 control이 logarithmic mapping을 적용해야 합니다.

Backlight scale 값

값Brightness 변화Control mapping

unknownCurve scale을 알 수 없음정의되지 않음

linear각 step마다 linear하게 변함Logarithmic mapping을 적용

non-linear각 step마다 non-linear하게 변함Linear mapping을 적용

Brightness curve 종류와 사람이 선형적으로 느끼게 하기 위한 control mapping입니다.

Ambient light sensor conversion 값

28-47

항목	한국어 전문 번역
What	/sys/class/backlight/<backlight>/ambient_light_level
Date	2010년 4월
KernelVersion	v2.6.35
Contact	Michael Hennerich <michael.hennerich@analog.com>
Description	(RO) Light sensor의 conversion 값을 가져옵니다. Light sensor가 활성화되어 있으면 값은 80 ms마다 자동으로 갱신됩니다. 값 범위는 device driver별로 다릅니다.

Ambient light level 범위

Driver반환 값

ADP88700(dark)-8000(max ambient brightness) 정수

ADP886013-bit 정수

ADP8870과 ADP8860 driver가 반환하는 sensor conversion 값 형식입니다.

Ambient light zone 선택

49-86

항목	한국어 전문 번역
What	/sys/class/backlight/<backlight>/ambient_light_zone
Date	2010년 4월
KernelVersion	v2.6.35
Contact	Michael Hennerich <michael.hennerich@analog.com>; device-drivers-devel@blackfin.uclinux.org
Description	(RW) Backlight가 동작할 특정 brightness level을 읽거나 씁니다. 값의 의미는 device driver별로 다릅니다. 0을 쓰면 normal/automatic ambient light level operation으로 돌아갑니다. /sys/class/backlight/<backlight>/max_brightness에 저장된 값을 /sys/class/backlight/<backlight>/brightness에 쓰면 이 기능을 활성화할 수 있습니다.

Ambient light zone 값

값ADP8860ADP8870

0Off: 0 mAOff: 0 mA

1Level 1: daylightLevel 1: daylight

2Level 2: brightLevel 2: bright

3Level 3: darkLevel 3: office

4-Level 4: indoor

5-Level 5: dark

ADP8860과 ADP8870이 zone 번호에 부여하는 brightness 환경입니다.

Ambient light zone 최대 brightness

88-135

항목	한국어 전문 번역
What	/sys/class/backlight/<backlight>/<ambient light zone>_max
Date	2009년 9월
KernelVersion	v2.6.32
Contact	device-drivers-devel@blackfin.uclinux.org
Description	이 <backlight>에서 <ambient light zone>의 최대 brightness를 제어합니다. 값 범위는 0-127이며 이 file을 읽으면 해당 zone에 저장된 brightness level도 표시합니다. <ambient light zone> 이름은 device driver별로 다릅니다. 관련 속성은 /sys/class/backlight/<backlight>/ambient_light_zone을 참조합니다.

Driver별 ambient light zone 최대값 경로

DriverZoneSysfs entry

ADP5520 / ADP5501daylight/sys/class/backlight/<backlight>/daylight_max

ADP5520 / ADP5501office/sys/class/backlight/<backlight>/office_max

ADP5520 / ADP5501dark/sys/class/backlight/<backlight>/dark_max

ADP8860l1_daylight/sys/class/backlight/<backlight>/l1_daylight_max

ADP8860l2_office/sys/class/backlight/<backlight>/l2_office_max

ADP8860l3_dark/sys/class/backlight/<backlight>/l3_dark_max

ADP8870l1_daylight/sys/class/backlight/<backlight>/l1_daylight_max

ADP8870l2_bright/sys/class/backlight/<backlight>/l2_bright_max

ADP8870l3_office/sys/class/backlight/<backlight>/l3_office_max

ADP8870l4_indoor/sys/class/backlight/<backlight>/l4_indoor_max

ADP8870l5_dark/sys/class/backlight/<backlight>/l5_dark_max

각 driver family가 <ambient light zone>_max에 사용하는 zone 이름과 sysfs entry입니다.

Ambient light zone dim brightness

137-185

항목	한국어 전문 번역
What	/sys/class/backlight/<backlight>/<ambient light zone>_dim
Date	2009년 9월
KernelVersion	v2.6.32
Contact	device-drivers-devel@blackfin.uclinux.org
Description	이 <backlight>에서 <ambient light zone>의 dim brightness를 제어합니다. 값 범위는 0-127이고 일반적으로 0으로 설정합니다. Backlight가 비활성화되면 완전히 꺼집니다. 이 file을 읽으면 해당 zone에 저장된 dim brightness level도 표시합니다. <ambient light zone> 이름은 device driver별로 다릅니다. 관련 속성은 /sys/class/backlight/<backlight>/ambient_light_zone을 참조합니다.

Driver별 ambient light zone dim 경로

DriverZoneSysfs entry

ADP5520 / ADP5501daylight/sys/class/backlight/<backlight>/daylight_dim

ADP5520 / ADP5501office/sys/class/backlight/<backlight>/office_dim

ADP5520 / ADP5501dark/sys/class/backlight/<backlight>/dark_dim

ADP8860l1_daylight/sys/class/backlight/<backlight>/l1_daylight_dim

ADP8860l2_office/sys/class/backlight/<backlight>/l2_office_dim

ADP8860l3_dark/sys/class/backlight/<backlight>/l3_dark_dim

ADP8870l1_daylight/sys/class/backlight/<backlight>/l1_daylight_dim

ADP8870l2_bright/sys/class/backlight/<backlight>/l2_bright_dim

ADP8870l3_office/sys/class/backlight/<backlight>/l3_office_dim

ADP8870l4_indoor/sys/class/backlight/<backlight>/l4_indoor_dim

ADP8870l5_dark/sys/class/backlight/<backlight>/l5_dark_dim

각 driver family가 <ambient light zone>_dim에 사용하는 zone 이름과 sysfs entry입니다.