src.android.hardware.hdmi.HdmiUtils Maven / Gradle / Ivy
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/*
* Copyright (C) 2018 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package android.hardware.hdmi;
import android.annotation.IntDef;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
/**
* Various utilities related to HDMI CEC.
*
* @hide
*/
public final class HdmiUtils {
/**
* Return value of {@link #getLocalPortFromPhysicalAddress(int, int)}
*/
static final int TARGET_NOT_UNDER_LOCAL_DEVICE = -1;
static final int TARGET_SAME_PHYSICAL_ADDRESS = 0;
private HdmiUtils() { /* cannot be instantiated */ }
/**
* Method to parse target physical address to the port number on the current device.
*
* This check assumes target address is valid.
*
* @param targetPhysicalAddress is the physical address of the target device
* @param myPhysicalAddress is the physical address of the current device
* @return
* If the target device is under the current device, return the port number of current device
* that the target device is connected to. This also applies to the devices that are indirectly
* connected to the current device.
*
*
If the target device has the same physical address as the current device, return
* {@link #TARGET_SAME_PHYSICAL_ADDRESS}.
*
*
If the target device is not under the current device, return
* {@link #TARGET_NOT_UNDER_LOCAL_DEVICE}.
*/
public static int getLocalPortFromPhysicalAddress(
int targetPhysicalAddress, int myPhysicalAddress) {
if (myPhysicalAddress == targetPhysicalAddress) {
return TARGET_SAME_PHYSICAL_ADDRESS;
}
int mask = 0xF000;
int finalMask = 0xF000;
int maskedAddress = myPhysicalAddress;
while (maskedAddress != 0) {
maskedAddress = myPhysicalAddress & mask;
finalMask |= mask;
mask >>= 4;
}
int portAddress = targetPhysicalAddress & finalMask;
if ((portAddress & (finalMask << 4)) != myPhysicalAddress) {
return TARGET_NOT_UNDER_LOCAL_DEVICE;
}
mask <<= 4;
int port = portAddress & mask;
while ((port >> 4) != 0) {
port >>= 4;
}
return port;
}
/**
* @hide
*/
@Retention(RetentionPolicy.SOURCE)
@IntDef({HDMI_RELATIVE_POSITION_UNKNOWN, HDMI_RELATIVE_POSITION_DIRECTLY_BELOW,
HDMI_RELATIVE_POSITION_BELOW, HDMI_RELATIVE_POSITION_SAME,
HDMI_RELATIVE_POSITION_DIRECTLY_ABOVE, HDMI_RELATIVE_POSITION_ABOVE,
HDMI_RELATIVE_POSITION_SIBLING, HDMI_RELATIVE_POSITION_DIFFERENT_BRANCH})
public @interface HdmiAddressRelativePosition {}
/**
* HDMI relative position is not determined.
*
* @hide
*/
public static final int HDMI_RELATIVE_POSITION_UNKNOWN = 0;
/**
* HDMI relative position: directly blow the device.
*
* @hide
*/
public static final int HDMI_RELATIVE_POSITION_DIRECTLY_BELOW = 1;
/**
* HDMI relative position: indirectly below the device.
*
* @hide
*/
public static final int HDMI_RELATIVE_POSITION_BELOW = 2;
/**
* HDMI relative position: the same device.
*
* @hide
*/
public static final int HDMI_RELATIVE_POSITION_SAME = 3;
/**
* HDMI relative position: directly above the device.
*
* @hide
*/
public static final int HDMI_RELATIVE_POSITION_DIRECTLY_ABOVE = 4;
/**
* HDMI relative position: indirectly above the device.
*
* @hide
*/
public static final int HDMI_RELATIVE_POSITION_ABOVE = 5;
/**
* HDMI relative position: directly below a same device.
*
* @hide
*/
public static final int HDMI_RELATIVE_POSITION_SIBLING = 6;
/**
* HDMI relative position: different branch.
*
* @hide
*/
public static final int HDMI_RELATIVE_POSITION_DIFFERENT_BRANCH = 7;
private static final int NPOS = -1;
/**
* Check if the given physical address is valid.
*
* @param address physical address
* @return {@code true} if the given address is valid
*/
public static boolean isValidPhysicalAddress(int address) {
if (address < 0 || address >= 0xFFFF) {
return false;
}
int mask = 0xF000;
boolean hasZero = false;
for (int i = 0; i < 4; i++) {
if ((address & mask) == 0) {
hasZero = true;
} else if (hasZero) {
// only 0s are valid after a 0.
// e.g. 0x1012 is not valid.
return false;
}
mask >>= 4;
}
return true;
}
/**
* Returns the relative position of two physical addresses.
*/
@HdmiAddressRelativePosition
public static int getHdmiAddressRelativePosition(int src, int dest) {
if (src == 0xFFFF || dest == 0xFFFF) {
// address not assigned
return HDMI_RELATIVE_POSITION_UNKNOWN;
}
try {
int firstDiffPos = physicalAddressFirstDifferentDigitPos(src, dest);
if (firstDiffPos == NPOS) {
return HDMI_RELATIVE_POSITION_SAME;
}
int mask = (0xF000 >> (firstDiffPos * 4));
int nextPos = firstDiffPos + 1;
if ((src & mask) == 0) {
// src is above dest
if (nextPos == 4) {
// last digits are different
return HDMI_RELATIVE_POSITION_DIRECTLY_ABOVE;
}
if (((0xF000 >> (nextPos * 4)) & dest) == 0) {
// next digit is 0
return HDMI_RELATIVE_POSITION_DIRECTLY_ABOVE;
}
return HDMI_RELATIVE_POSITION_ABOVE;
}
if ((dest & mask) == 0) {
// src is below dest
if (nextPos == 4) {
// last digits are different
return HDMI_RELATIVE_POSITION_DIRECTLY_BELOW;
}
if (((0xF000 >> (nextPos * 4)) & src) == 0) {
// next digit is 0
return HDMI_RELATIVE_POSITION_DIRECTLY_BELOW;
}
return HDMI_RELATIVE_POSITION_BELOW;
}
if (nextPos == 4) {
// last digits are different
return HDMI_RELATIVE_POSITION_SIBLING;
}
if (((0xF000 >> (nextPos * 4)) & src) == 0 && ((0xF000 >> (nextPos * 4)) & dest) == 0) {
return HDMI_RELATIVE_POSITION_SIBLING;
}
return HDMI_RELATIVE_POSITION_DIFFERENT_BRANCH;
} catch (IllegalArgumentException e) {
// invalid address
return HDMI_RELATIVE_POSITION_UNKNOWN;
}
}
private static int physicalAddressFirstDifferentDigitPos(int address1, int address2)
throws IllegalArgumentException {
if (!isValidPhysicalAddress(address1)) {
throw new IllegalArgumentException(address1 + " is not a valid address.");
}
if (!isValidPhysicalAddress(address2)) {
throw new IllegalArgumentException(address2 + " is not a valid address.");
}
int mask = 0xF000;
for (int i = 0; i < 4; i++) {
if ((address1 & mask) != (address2 & mask)) {
return i;
}
mask = mask >> 4;
}
return NPOS;
}
}