蓝牙 hci

  1 /*
  2 
  3  There are two basic types of physical links that can be established
  4  between a master and a slave:
  5 
  6  Synchronous Connection Oriented ( SCO )
  7  Asynchronous Connection-Less ( ACL )
  8 
  9  An SCO link provides a symmetric link between the master and the slave,
 10  ***********
 11  with regular periodic exchange of data in the form of reserved slots.
 12  Thus, the SCO link provides a circuit-switched connection
 13  where data are regularly exchanged,
 14  and as such it is intended for use with time-bounded information as audio.
 15 
 16  A master can support up to three SCO links to the same or to different slaves.
 17  A slave can support up to three SCO links from the same master.
 18 
 19  Audio - Audio data is carried via SCO (Synchronous Connection Oriented) channels
 20 
 21  An ACI link is a point-to-multipoint link between the master
 22  ***********
 23  and all the slaves on the piconet. It can use all of the remaining slots
 24  on the channel not used for SCO links.
 25  The ACL link provides a packet-switched connection
 26  where data are exchanged sporadically,
 27  as they become available from higher layers of the stack.
 28 
 29  The traffic over the ACL link is completely scheduled by the master.
 30 
 31  Each Bluetooth device has a 48 bit IEEE MAC address that
 32  is used for the derivation of the access code.
 33 
 34  The form of a MAC address - Copyright Spill & Bittau
 35  NAP[15:0] : UAP[7:0] : LAP[23:0]
 36  The NAP is only two bytes long and the First byte is generally zero
 37 
 38  All packets have the same format, starting with an access code,
 39  followed by a packet header and ending with the user payload
 40 
 41  Access Code       Header      Payload
 42  68 or 72 bits     54 bits     0 - 2745 bits
 43 
 44  The access code is used to address the packet to a specific device.
 45  The header contains all the control information associated with the packet and the link.
 46  The payload contains the actual message information.
 47 
 48 
 49  An HCI packet consisting of an HCI header and HCI data
 50  shall be contained in one USB Transfer.
 51 
 52  A USB transfer is defined by the USB specification as
 53  one or more USB transactions that contain the data from one IO request
 54 
 55  For example,
 56  an ACL data packet containing 256 bytes (both HCI header and HCI data)
 57  would be sent over the bulk endpoint in one IO request
 58 
 59  That IO request will require four 64-byte full speed USB Transactions or
 60  a single 256-byte Highspeed USB Transaction, and forms a Transfer
 61 
 62  If the Maximum Packet Size for the endpoint on which the transfer is sent
 63  is 64 bytes, then that IO request will require four 64-byte USB transactions.
 64 
 65  USB Primary firmware interface and endpoint settings
 66 
 67  Interface   Alternate   Endpoint    Endpoint        PacketSize
 68  Number      Setting     Address     Type
 69  HCI Commands  N/A         N/A         0x00        Control         8/64
 70  HCI Events    0           0           0x81        Interrupt   16
 71  ACL/AMP Data  0           0           0x82        Bulk        64
 72  ACL/AMP Data  0           0           0x02        Bulk       64
 73 
 74  *************** CONTROL ENDPOINT EXPECTATIONS **********************************
 75 
 76  Endpoint 0 is used to configure and control the USB device.
 77  Endpoint 0 will also be used to allow the host to
 78  send HCI-specific commands to the host controller.
 79 
 80  All HCI Control Packets delivered to Endpoint 0 are addressed
 81  in the Setup Data structure
 82 
 83  The bmRequestType can be used to select the Device or the Interface.
 84  If Interface is selected, the wIndex parameter
 85  must select the Index for the targeted Bluetooth controller
 86 
 87  For a single function Primary Controller,
 88  the Host should address HCI command packets to the Device.
 89  HCI command packets should be sent with the following parameters:
 90 
 91  *** HCI command packet addressing for single-function Primary controllers :
 92 
 93  bmRequestType 0x20 : Host-to-device class request, device as target
 94  bRequest      0x00
 95  wValue        0x00
 96  wIndex        0x00
 97 
 98  Note: For historical reasons, if the Primary Controller firmware receives a
 99  packet over this endpoint, it should treat the packet as an HCI command
100  packet regardless of the value of bRequest, wValue and wIndex.
101  Some Host devices set bRequest to 0xE0.
102 
103  *** Primary Controller Function in a Composite Device
104 
105  bmRequestType 0x21 : Host-to-interface class request, interface as target
106  bRequest      0x00
107  wValue        0x00
108  wIndex        IF# : This is the actual Interface # within the composite device.
109 
110  If the Host system driver addresses USB requests containing HCI command packets
111  to the Device instead of to the Interface, the device implementation shall
112  recognize these HCI command packets and correctly route them to
113  the Primary Controller function, to ensure correct operation of
114  the Primary Controller function and avoid malfunctions in other functions
115  contained in the composite device.
116 
117  *** HCI command packet addressing for single-function AMP Controller
118 
119  bmRequestType 0x21 : Host-to-interface class request, interface as target
120  bRequest      0x2B : Arbitrary value chosen to identify requests targeted to an AMP controller function.
121  wValue        0x00
122  wIndex        IF# : This is the actual Interface # within the composite device.
123 
124 
125  *************** BULK ENDPOINT EXPECTATIONS *************************************
126 
127  Data integrity is a critical aspect for ACL data. This,
128  in combination with bandwidth requirements,
129  is the reason for using a bulk endpoint. Multiple 64-byte packets can be shipped
130  per USB Frame (1 millisecond, full speed) or 512-byte packets per USB Microframe
131  (125 microseconds, high-speed), across the bus.
132 
133  Suggested bulk max packet size is 64 bytes for full-speed,
134  or 512 bytes for high speed.
135 
136  Bulk has the ability to detect errors and correct them.
137  In order to avoid starvation, a flow control model similar
138  to the shared endpoint model is recommended for the host controller.
139 
140  ***************INTERRUPT ENDPOINT EXPECTATIONS *********************************
141 
142  An interrupt endpoint is necessary to ensure that events are delivered
143  in a predictable and timely manner.
144  Event packets can be sent across USB with a guaranteed latency.
145 
146  The interrupt endpoint should have an interval of 1 ms (full speed).
147  For a controller using USB high-speed the interrupt interval may have
148  an interval of 125 microseconds.
149 
150  The USB software and firmware requires no intimate knowledge of the events
151  passed to the host controller.
152 
153  ***************ISOCHRONOUS ENDPOINT EXPECTATIONS *******************************
154 
155  These isochronous endpoints transfer synchronous data to and from the host
156  controller of the radio.
157 
158  Time is the critical aspect for this type of data.
159  The USB firmware should transfer the contents of the data
160  to the host controllers' synchronous FIFOs.
161  If the FIFOs are full, the data should be overwritten with new data.
162  These endpoints have a one (1) ms interval, as required by Chapter 9 of the
163  USB Specification, Versions 1.0 and 1.1.
164 
165  A suggested max packet size for this endpoint would be at least 64 bytes.
166 
167  ********************** BLUETOOTH CODES *****************************************
168 
169  The following values are defined for Bluetooth Devices:
170 
171  Device/Inferface : USB Codes for Primary Controllers :
172  Class     bDeviceClass    0xE0    Wireless Controller
173  Subclass  bDeviceSubClass 0x01    RF Controller
174  Protocol  bDeviceProtocol 0x01    Bluetooth Pri Controller < bRequest : 0x00 >
175 
176  Device/Inferface : USB Codes for AMP Controllers :
177  Class     bDeviceClass    0xE0    Wireless Controller
178  Subclass  bDeviceSubClass 0x01    RF Controller
179  Protocol  bDeviceProtocol 0x04    Bluetooth AMP Controller < bRequest : 0x2B >
180 
181  These values should also be used in the interface descriptors for the interfaces
182 
183  Device : USB Codes for composite devices using IAD :
184  Class     bDeviceClass    0xEF    Miscellaneous
185  Subclass  bDeviceSubClass 0x02    Common Class
186  Protocol  bDeviceProtocol 0x01    Interface Association Descriptor
187 
188  Interface : USB Codes for Primary Controllers :
189  Class     bDeviceClass    0xE0    Wireless Controller
190  Subclass  bDeviceSubClass 0x01    RF Controller
191  Protocol  bDeviceProtocol 0x01    Bluetooth Pri Controller < bRequest : 0x00 >
192 
193  Interface : USB Codes for AMP Controllers :
194  Class     bDeviceClass    0xE0    Wireless Controller
195  Subclass  bDeviceSubClass 0x01    RF Controller
196  Protocol  bDeviceProtocol 0x04    Bluetooth AMP Controller < bRequest : 0x2B >
197 
198  ************* BLUETOOTH COMPOSITE DEVICE IMPLEMENTATION ************************
199 
200  (IAD) : Interface Association Descriptors
201 
202  Example Interface Association Descriptor used for a Primary Controller function:
203 
204  Offset  Field             Size  Value     Description
205  0       bLength           1     0x08      Size of this descriptor in octets
206  1       bDescriptorType   1     0x0B      INTERFACE ASSOCIATION DESCRIPTOR
207  2       bFirstInterface   1     xxxx      Interface number of the first interface associated with this device
208  3       bInterfaceCount   1     0x02      Number of contiguous interfaces associated with the function
209  4       bFunctionClass    1     0xE0      Wireless Controller
210  5       bFunctionSubClass 1     0x01      RF Controller
211  6       bFunctionProtocol 1     0x01      Bluetooth Primary Controller
212  7       iFunction         1     xxxx      Index Pointer to a name string for this function, if any is provide
213 
214  A USB Composite contains multiple independent functions. This section
215  describes how to implement Bluetooth functions within a USB Composite
216  device. This may require the use of Interface Association Descriptors (IAD) to
217  aggregate multiple Interfaces. This also requires the host to address USB
218  requests to the specific Interface
219 
220  A Primary Controller (ref) shall contain at least two interfaces:
221  HCI Events and ACL data (3 endpoints)
222  HCI SCO data (2 endpoints, multiple alternate settings)
223 
224  When used in a USB Composite device, a Primary Controller function shall use
225  an IAD descriptor to associate the provided interfaces.
226 
227  When used in a USB Composite device, an AMP Controller does not need IAD.
228  If the device contains the Device Firmware Upgrade option as a separate
229  Device function, an IAD is not needed. If the Device Firmware Upgrade option
230  is bundled with the AMP Controller function, then an IAD is needed to bind the
231  two interfaces.
232 
233  A USB Composite device containing only a Primary Controller and an AMP Controller
234  may include a Configuration Descriptor set with the following structure:
235 
236  Configuration Descriptor :
237 
238  0x09, 0x02, wTotalLength,
239  0x03,
240  // bNumInterfaces
241  // IF#1 Primary events & ACL
242  // IF#2 Primary SCO or eSCO
243  // IF#3 AMP events & ACL
244  0x01, // bConfigurationValue
245  iConfiguration,
246  bmAttributes,
247  0xFA, // Max power used 500ma
248 
249  Interface Association Descriptor :
250 
251  0x08, 0x0B,
252  IF#1, // bFirstInterface
253  0x03, // bInterfaceCount : Number of contiguous interfaces associated with the function.
254  0xE0, 0x01, 0x01, // Wireless Controller : RF Controller : Bluetooth Primary Controller
255  iFunctionString
256 
257  INTERFACE DESCRIPTOR #1
258  0x09, 0x04, IF#1, 0x00, 0x03, // bNumEndpoints : InterruptIn, BulkIn, BulkOut
259  0xE0, 0x01, 0x01, // Wireless Controller : RF Controller : Bluetooth Primary Controller
260  iInterfaceString
261 
262  ENDPOINT DESCRIPTOR : Interrupt, Bulk In, Bulk Out
263 
264  INTERFACE DESCRIPTOR #2
265 
266  0x09, 0x04, IF#2, 0x00, 0x02, // bNumEndpoints : Isoch OUT (SCO), Isoch IN (SCO)
267  0xE0, 0x01, 0x01, // Wireless Controller : RF Controller : Bluetooth Primary Controller
268  iInterfaceString
269 
270  ENDPOINT DESCRIPTOR : Iso In, Iso Out
271 
272  INTERFACE DESCRIPTOR #3
273 
274  0x09, 0x04, IF#3, 0x00, 0x03, // bNumEndpoints : Isoch OUT (SCO), Isoch IN (SCO)
275  0xE0, 0x01, 0x04, // Wireless Controller : RF Controller : Bluetooth AMP Controller
276  iInterfaceString
277 
278  ENDPOINT DESCRIPTOR : Interrupt, Bulk In, Bulk Out
279 
280  LOGICAL LINK CONTROL AND ADAPTATION PROTOCOL SPECIFICATION : L2CAP
281 
282  DATA PACKET FORMAT
283  SIGNALING PACKET FORMATS
284 
285  SERVICE DISCOVERY PROTOCOL SPECIFICATION : SDP
286 
287  GENERIC ACCESS PROFILE
288 
289  AMP MANAGER PROTOCOL SPECIFICATION
290 
291  ATTRIBUTE PROTOCOL (ATT)
292 
293  GENERIC ATTRIBUTE PROFILE (GATT)
294 
295  SECURITY MANAGER SPECIFICATION
296 
297  */

你可能感兴趣的:(蓝牙 hci)