arm: tegra: hawkeye: apply backlight transfer function

Adjust backlight update requests to create a nonlinear
change in brightness (smaller increments at lower
backlight levels, larger increments at higher backlight
levels).
The current curve data is borrowed from Shield Tablet 8.

Bug 1647733

Change-Id: Iccea5b5e34a5cd2ee759fecf7b86a4a0d0b57deb
Signed-off-by: Daniel Solomon <daniels@nvidia.com>
Reviewed-on: http://git-master/r/745148
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

diff --git a/arch/arm64/boot/dts/tegra210-hawkeye-p2290-common.dtsi b/arch/arm64/boot/dts/tegra210-hawkeye-p2290-common.dtsi
index 3fb2e77f3fa7714833123a07180d9127dc126fa5..0dab663b182416ef44a1bcf5d238f48f3814e225 100644 (file)
--- a/arch/arm64/boot/dts/tegra210-hawkeye-p2290-common.dtsi
+++ b/arch/arm64/boot/dts/tegra210-hawkeye-p2290-common.dtsi
@@ -287,6 +287,39 @@
                                        238 239 240 241 242 244 245 246
                                        247 248 249 250 251 253 254 255 >;
 
+                       bl-curve = < 0 1 1 2 2 3 3 4
+                                       4 5 5 6 7 7 8 8
+                                       9 9 10 10 11 11 12 12
+                                       13 14 14 15 15 16 16 17
+                                       17 18 18 19 20 20 21 21
+                                       22 22 23 23 24 24 25 25
+                                       26 27 27 28 28 29 29 30
+                                       30 31 31 32 33 33 34 34
+                                       35 35 36 36 37 37 38 38
+                                       39 40 40 41 41 42 42 43
+                                       43 44 44 45 46 46 47 47
+                                       48 48 49 49 50 50 51 52
+                                       52 53 53 54 54 55 55 56
+                                       56 57 57 58 59 59 60 60
+                                       61 61 62 62 63 63 64 65
+                                       65 66 66 67 67 68 68 69
+                                       69 70 70 71 72 72 73 73
+                                       74 74 75 75 76 76 77 78
+                                       78 79 79 80 80 81 81 82
+                                       82 83 83 84 85 85 86 86
+                                       87 87 88 88 89 89 90 92
+                                       94 96 97 99 101 103 105 107
+                                       109 110 112 114 116 118 120 122
+                                       123 125 127 129 131 133 134 136
+                                       138 140 142 144 146 147 149 151
+                                       153 155 157 159 160 162 164 166
+                                       168 170 172 173 175 177 179 181
+                                       183 185 186 188 190 192 194 196
+                                       198 199 201 203 205 207 209 211
+                                       212 214 216 218 220 222 223 225
+                                       227 229 231 233 235 236 238 240
+                                       242 244 246 248 249 251 253 255 >;
+
                        /* 5 LED string */
                        rom_14h {
                                rom-addr = /bits/ 8 <0x14>;