Expose device RSSI and Tx power via the chrome.bluetooth API.

This CL only implements the fetching of these values on Mac.

BUG=365966
TEST=browser_tests
R=kalman@chromium.org, keybuk@chromium.org

Review URL: https://codereview.chromium.org/246603008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@267458 0039d316-1c4b-4281-b951-d872f2087c98

9 files changed, 137 insertions, 6 deletions

diff --git a/device/bluetooth/bluetooth_device.h b/device/bluetooth/bluetooth_device.h
index 28fd7ac..220066c 100644
--- a/device/bluetooth/bluetooth_device.h
+++ b/device/bluetooth/bluetooth_device.h
@@ -66,6 +66,9 @@ class BluetoothDevice {
     DEVICE_KEYBOARD_MOUSE_COMBO
   };
 
+  // The value returned if the RSSI or transmit power cannot be read.
+  static const int kUnknownPower = 127;
+
   // Possible errors passed back to an error callback function in case of a
   // failed call to Connect().
   enum ConnectErrorCode {
@@ -227,6 +230,28 @@ class BluetoothDevice {
   // DEVICE_PERIPHERAL.
   DeviceType GetDeviceType() const;
 
+  // Gets the "received signal strength indication" (RSSI) of the current
+  // connection to the device. The RSSI indicates the power present in the
+  // received radio signal, measured in dBm, to a resolution of 1dBm. Larger
+  // (typically, less negative) values indicate a stronger signal.
+  // If the device is not currently connected, then returns the RSSI read from
+  // the last inquiry that returned the device, where available. In case of an
+  // error, returns |kUnknownPower|. Otherwise, returns the connection's RSSI.
+  virtual int GetRSSI() const = 0;
+
+  // These two methods are used to read the current or maximum transmit power
+  // ("Tx power") of the current connection to the device. The transmit power
+  // indicates the strength of the signal broadcast from the host's Bluetooth
+  // antenna when communicating with the device, measured in dBm, to a
+  // resolution of 1dBm. Larger (typically, less negative) values
+  // indicate a stronger signal.
+  // It is only meaningful to call this method when there is a connection
+  // established to the device. If there is no connection, or in case of an
+  // error, returns |kUnknownPower|. Otherwise, returns the connection's
+  // transmit power.
+  virtual int GetCurrentHostTransmitPower() const = 0;
+  virtual int GetMaximumHostTransmitPower() const = 0;
+
   // Indicates whether the device is known to support pairing based on its
   // device class and address.
   bool IsPairable() const;
diff --git a/device/bluetooth/bluetooth_device_chromeos.cc b/device/bluetooth/bluetooth_device_chromeos.cc
index b5f7386..e894136 100644
--- a/device/bluetooth/bluetooth_device_chromeos.cc
+++ b/device/bluetooth/bluetooth_device_chromeos.cc
@@ -212,6 +212,21 @@ uint16 BluetoothDeviceChromeOS::GetDeviceID() const {
   return device_id;
 }
 
+int BluetoothDeviceChromeOS::GetRSSI() const {
+  NOTIMPLEMENTED();
+  return kUnknownPower;
+}
+
+int BluetoothDeviceChromeOS::GetCurrentHostTransmitPower() const {
+  NOTIMPLEMENTED();
+  return kUnknownPower;
+}
+
+int BluetoothDeviceChromeOS::GetMaximumHostTransmitPower() const {
+  NOTIMPLEMENTED();
+  return kUnknownPower;
+}
+
 bool BluetoothDeviceChromeOS::IsPaired() const {
   BluetoothDeviceClient::Properties* properties =
       DBusThreadManager::Get()->GetBluetoothDeviceClient()->
diff --git a/device/bluetooth/bluetooth_device_chromeos.h b/device/bluetooth/bluetooth_device_chromeos.h
index 156d9ea..96265ae 100644
--- a/device/bluetooth/bluetooth_device_chromeos.h
+++ b/device/bluetooth/bluetooth_device_chromeos.h
@@ -37,6 +37,9 @@ class BluetoothDeviceChromeOS
   virtual uint16 GetVendorID() const OVERRIDE;
   virtual uint16 GetProductID() const OVERRIDE;
   virtual uint16 GetDeviceID() const OVERRIDE;
+  virtual int GetRSSI() const OVERRIDE;
+  virtual int GetCurrentHostTransmitPower() const OVERRIDE;
+  virtual int GetMaximumHostTransmitPower() const OVERRIDE;
   virtual bool IsPaired() const OVERRIDE;
   virtual bool IsConnected() const OVERRIDE;
   virtual bool IsConnectable() const OVERRIDE;
diff --git a/device/bluetooth/bluetooth_device_mac.h b/device/bluetooth/bluetooth_device_mac.h
index ec87ff7..1503f1dc 100644
--- a/device/bluetooth/bluetooth_device_mac.h
+++ b/device/bluetooth/bluetooth_device_mac.h
@@ -5,6 +5,8 @@
 #ifndef DEVICE_BLUETOOTH_BLUETOOTH_DEVICE_MAC_H_
 #define DEVICE_BLUETOOTH_BLUETOOTH_DEVICE_MAC_H_
 
+#import <IOBluetooth/IOBluetooth.h>
+
 #include <string>
 
 #include "base/basictypes.h"
@@ -32,6 +34,9 @@ class BluetoothDeviceMac : public BluetoothDevice {
   virtual uint16 GetVendorID() const OVERRIDE;
   virtual uint16 GetProductID() const OVERRIDE;
   virtual uint16 GetDeviceID() const OVERRIDE;
+  virtual int GetRSSI() const OVERRIDE;
+  virtual int GetCurrentHostTransmitPower() const OVERRIDE;
+  virtual int GetMaximumHostTransmitPower() const OVERRIDE;
   virtual bool IsPaired() const OVERRIDE;
   virtual bool IsConnected() const OVERRIDE;
   virtual bool IsConnectable() const OVERRIDE;
@@ -72,6 +77,11 @@ class BluetoothDeviceMac : public BluetoothDevice {
  private:
   friend class BluetoothAdapterMac;
 
+  // Implementation to read the host's transmit power level of type
+  // |power_level_type|.
+  int GetHostTransmitPower(
+      BluetoothHCITransmitPowerLevelType power_level_type) const;
+
   // List of observers interested in event notifications from us.
   ObserverList<Observer> observers_;
 
diff --git a/device/bluetooth/bluetooth_device_mac.mm b/device/bluetooth/bluetooth_device_mac.mm
index 24c2b45..aaeffb8 100644
--- a/device/bluetooth/bluetooth_device_mac.mm
+++ b/device/bluetooth/bluetooth_device_mac.mm
@@ -4,11 +4,6 @@
 
 #include "device/bluetooth/bluetooth_device_mac.h"
 
-#include <IOBluetooth/Bluetooth.h>
-#import <IOBluetooth/objc/IOBluetoothDevice.h>
-#import <IOBluetooth/objc/IOBluetoothSDPServiceRecord.h>
-#import <IOBluetooth/objc/IOBluetoothSDPUUID.h>
-
 #include <string>
 
 #include "base/basictypes.h"
@@ -28,13 +23,23 @@
 
 @interface IOBluetoothDevice (LionSDKDeclarations)
 - (NSString*)addressString;
-- (NSString*)name;
 - (unsigned int)classOfDevice;
+- (BluetoothConnectionHandle)connectionHandle;
+- (BluetoothHCIRSSIValue)rawRSSI;
 - (NSArray*)services;
 @end
 
 #endif  // MAC_OS_X_VERSION_10_7
 
+// Undocumented API for accessing the Bluetooth transmit power level.
+// Similar to the API defined here [ http://goo.gl/20Q5vE ].
+@interface IOBluetoothHostController (UndocumentedAPI)
+- (IOReturn)
+    BluetoothHCIReadTransmitPowerLevel:(BluetoothConnectionHandle)connection
+                                inType:(BluetoothHCITransmitPowerLevelType)type
+                 outTransmitPowerLevel:(BluetoothHCITransmitPowerLevel*)level;
+@end
+
 namespace device {
 
 BluetoothDeviceMac::BluetoothDeviceMac(IOBluetoothDevice* device)
@@ -84,6 +89,30 @@ uint16 BluetoothDeviceMac::GetDeviceID() const {
   return 0;
 }
 
+int BluetoothDeviceMac::GetRSSI() const {
+  if (![device_ isConnected]) {
+    NOTIMPLEMENTED();
+    return kUnknownPower;
+  }
+
+  int rssi = [device_ rawRSSI];
+
+  // The API guarantees that +127 is returned in case the RSSI is not readable:
+  // http://goo.gl/bpURYv
+  if (rssi == 127)
+    return kUnknownPower;
+
+  return rssi;
+}
+
+int BluetoothDeviceMac::GetCurrentHostTransmitPower() const {
+  return GetHostTransmitPower(kReadCurrentTransmitPowerLevel);
+}
+
+int BluetoothDeviceMac::GetMaximumHostTransmitPower() const {
+  return GetHostTransmitPower(kReadMaximumTransmitPowerLevel);
+}
+
 bool BluetoothDeviceMac::IsPaired() const {
   return [device_ isPaired];
 }
@@ -183,4 +212,26 @@ void BluetoothDeviceMac::ClearOutOfBandPairingData(
   NOTIMPLEMENTED();
 }
 
+int BluetoothDeviceMac::GetHostTransmitPower(
+    BluetoothHCITransmitPowerLevelType power_level_type) const {
+  IOBluetoothHostController* controller =
+      [IOBluetoothHostController defaultController];
+
+  // Bail if the undocumented API is unavailable on this machine.
+  SEL selector = @selector(
+      BluetoothHCIReadTransmitPowerLevel:inType:outTransmitPowerLevel:);
+  if (![controller respondsToSelector:selector])
+    return kUnknownPower;
+
+  BluetoothHCITransmitPowerLevel power_level;
+  IOReturn result =
+      [controller BluetoothHCIReadTransmitPowerLevel:[device_ connectionHandle]
+                                              inType:power_level_type
+                               outTransmitPowerLevel:&power_level];
+  if (result != kIOReturnSuccess)
+    return kUnknownPower;
+
+  return power_level;
+}
+
 }  // namespace device
diff --git a/device/bluetooth/bluetooth_device_win.cc b/device/bluetooth/bluetooth_device_win.cc
index 81a9386..53995ff 100644
--- a/device/bluetooth/bluetooth_device_win.cc
+++ b/device/bluetooth/bluetooth_device_win.cc
@@ -111,6 +111,21 @@ uint16 BluetoothDeviceWin::GetDeviceID() const {
   return 0;
 }
 
+int BluetoothDeviceWin::GetRSSI() const {
+  NOTIMPLEMENTED();
+  return kUnknownPower;
+}
+
+int BluetoothDeviceWin::GetCurrentHostTransmitPower() const {
+  NOTIMPLEMENTED();
+  return kUnknownPower;
+}
+
+int BluetoothDeviceWin::GetMaximumHostTransmitPower() const {
+  NOTIMPLEMENTED();
+  return kUnknownPower;
+}
+
 bool BluetoothDeviceWin::IsPaired() const {
   return paired_;
 }
diff --git a/device/bluetooth/bluetooth_device_win.h b/device/bluetooth/bluetooth_device_win.h
index 232da0f..128a87c 100644
--- a/device/bluetooth/bluetooth_device_win.h
+++ b/device/bluetooth/bluetooth_device_win.h
@@ -40,6 +40,9 @@ class BluetoothDeviceWin : public BluetoothDevice {
   virtual uint16 GetVendorID() const OVERRIDE;
   virtual uint16 GetProductID() const OVERRIDE;
   virtual uint16 GetDeviceID() const OVERRIDE;
+  virtual int GetRSSI() const OVERRIDE;
+  virtual int GetCurrentHostTransmitPower() const OVERRIDE;
+  virtual int GetMaximumHostTransmitPower() const OVERRIDE;
   virtual bool IsPaired() const OVERRIDE;
   virtual bool IsConnected() const OVERRIDE;
   virtual bool IsConnectable() const OVERRIDE;
diff --git a/device/bluetooth/test/mock_bluetooth_device.cc b/device/bluetooth/test/mock_bluetooth_device.cc
index 5235d5b..e8130da 100644
--- a/device/bluetooth/test/mock_bluetooth_device.cc
+++ b/device/bluetooth/test/mock_bluetooth_device.cc
@@ -26,6 +26,12 @@ MockBluetoothDevice::MockBluetoothDevice(MockBluetoothAdapter* adapter,
       .WillByDefault(testing::Return(address_));
   ON_CALL(*this, GetDeviceType())
       .WillByDefault(testing::Return(DEVICE_UNKNOWN));
+  ON_CALL(*this, GetRSSI())
+      .WillByDefault(testing::Return(kUnknownPower));
+  ON_CALL(*this, GetCurrentHostTransmitPower())
+      .WillByDefault(testing::Return(kUnknownPower));
+  ON_CALL(*this, GetMaximumHostTransmitPower())
+      .WillByDefault(testing::Return(kUnknownPower));
   ON_CALL(*this, GetVendorIDSource())
       .WillByDefault(testing::Return(VENDOR_ID_UNKNOWN));
   ON_CALL(*this, GetVendorID())
diff --git a/device/bluetooth/test/mock_bluetooth_device.h b/device/bluetooth/test/mock_bluetooth_device.h
index 4d910d1..9291e9b 100644
--- a/device/bluetooth/test/mock_bluetooth_device.h
+++ b/device/bluetooth/test/mock_bluetooth_device.h
@@ -38,6 +38,9 @@ class MockBluetoothDevice : public BluetoothDevice {
   MOCK_CONST_METHOD0(GetDeviceID, uint16());
   MOCK_CONST_METHOD0(GetName, base::string16());
   MOCK_CONST_METHOD0(GetDeviceType, BluetoothDevice::DeviceType());
+  MOCK_CONST_METHOD0(GetRSSI, int());
+  MOCK_CONST_METHOD0(GetCurrentHostTransmitPower, int());
+  MOCK_CONST_METHOD0(GetMaximumHostTransmitPower, int());
   MOCK_CONST_METHOD0(IsPaired, bool());
   MOCK_CONST_METHOD0(IsConnected, bool());
   MOCK_CONST_METHOD0(IsConnectable, bool());