| #!/bin/sh |
| |
| # Copyright (c) 2013 The Chromium OS Authors. All rights reserved. |
| # Use of this source code is governed by a BSD-style license that can be |
| # found in the LICENSE file. |
| # |
| # Sets a pre-determined calibration value for the ambient light sensor (ALS). |
| # The calibration value is either fetched from the VPD, determined by the |
| # ALS lens color set in the VPD, or set to a default value. |
| # |
| |
| DEFAULT_VALUE=7.65 |
| DEFAULT_VALUE_GRAY=7.65 |
| DEFAULT_VALUE_WHITE=2.15 |
| DEVICE_CALIBRATION_PATH=\ |
| /sys/bus/iio/devices/iio\:device0/in_illuminance0_calibscale |
| VPD_CALIBRATION_NAME=als_cal_data |
| VPD_LENS_COLOR_NAME=light_sensor_lens_color |
| |
| # |
| # Fetch the value for a VPD entry by name |
| # Value may be cached by dump_vpd_log |
| # $1: name of the VPD entry to fetch |
| # |
| get_vpd_entry() { |
| local output='' |
| local vpd_entry_name=$1 |
| # The VPD output format is: |
| # "als_cal_data"="1.337" |
| output=$(dump_vpd_log --full --stdout | \ |
| sed -n -r -e '/^"'${vpd_entry_name}'"=/s:^[^=]*="([^"]*)".*:\1:p') |
| |
| echo "${output}" |
| } |
| |
| # |
| # main |
| # |
| |
| # Look for per-device calibration data in the VPD |
| CALIBRATION_VALUE=$(get_vpd_entry "${VPD_CALIBRATION_NAME}") |
| if [ -z "${CALIBRATION_VALUE}" ]; then |
| # Fall back to a default value if per-device data not available |
| LENS_COLOR=$(get_vpd_entry "${VPD_LENS_COLOR_NAME}") |
| case "${LENS_COLOR}" in |
| "GRAY") |
| CALIBRATION_VALUE=${DEFAULT_VALUE_GRAY} |
| ;; |
| "WHITE") |
| CALIBRATION_VALUE=${DEFAULT_VALUE_WHITE} |
| ;; |
| *) |
| CALIBRATION_VALUE=${DEFAULT_VALUE} |
| ;; |
| esac |
| fi |
| |
| # Set calibration multiplier |
| echo "${CALIBRATION_VALUE}" > "${DEVICE_CALIBRATION_PATH}" |
