Documentation: Update Phonet doc for Pipe Controller implementation

Updates the Phonet document with description related to Pipe controller implementation Signed-off-by: Kumar Sanghvi <kumar.sanghvi@stericsson.com> Acked-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation: Update Phonet doc for Pipe Controller implementation
Updates the Phonet document with description related to Pipe controller implementation Signed-off-by: Kumar Sanghvi <kumar.sanghvi@stericsson.com> Acked-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Kumar Sanghvi · David S. Miller
1 parent 2ddaad397c
Showing 1 changed file with 53 additions and 0 deletions Side-by-side Diff
Documentation/networking/phonet.txt
@@ -182,6 +182,59 @@
     or zero if encapsulation is off.
  
  
+Phonet Pipe-controller Implementation
+-------------------------------------
+
+Phonet Pipe-controller is enabled by selecting the CONFIG_PHONET_PIPECTRLR Kconfig
+option. It is useful when communicating with those Nokia Modems which do not
+implement Pipe controller in them e.g. Nokia Slim Modem used in ST-Ericsson
+U8500 platform.
+
+The implementation is based on the Data Connection Establishment Sequence
+depicted in 'Nokia Wireless Modem API - Wireless_modem_user_guide.pdf'
+document.
+
+It allows a phonet sequenced socket (host-pep) to initiate a Pipe connection
+between itself and a remote pipe-end point (e.g. modem).
+
+The implementation adds socket options at SOL_PNPIPE level:
+
+ PNPIPE_CREATE
+	It accepts an integer argument where-in
+		lower order 16 bits: pn_dev and pn_port pair for remote pep.
+		higher order 16 bits: 8 bit pipe-handle
+
+	It sends a PNS_PEP_CONNECT_REQ on sequenced socket itself. On getting
+	PNS_PEP_CONNECT_RESP, it sends PNS_PEP_CONNECT_REQ to remote pep. On
+	getting response from remote pep, it selects the best possible Flow
+	control mechanism supported by remote-pep (modem) and then it sends
+	PNS_PEP_CREATED_IND to the sequenced socket and to the remote pep.
+
+	It then updates the pipe state associated with the sequenced socket to
+	be PIPE_DISABLED.
+
+  PNPIPE_ENABLE
+	It follows the same sequence as above for enabling a pipe by sending
+	PNS_PEP_ENABLE_REQ initially and then sending PNS_PEP_ENABLED_IND after
+	getting responses from sequenced socket and remote-pep.
+	It will also update the pipe state associated with the sequenced socket
+	to PIPE_ENABLED.
+
+   PNPIPE_DESTROY
+	This will send out PNS_PEP_DISCONNECT_REQ on the sequenced socket and
+	the remote pep.
+	It will also update the pipe state associated with the sequenced socket
+	to PIPE_IDLE
+
+   PNPIPE_INQ
+	This getsocktopt allows the user-space running on the sequenced socket
+	to examine the pipe state associated with that socket ie. whether the
+	pipe is created (PIPE_DISABLED) or enabled (PIPE_ENABLED) or disabled
+	(PIPE_DISABLED) or no pipe exists (PIPE_IDLE).
+
+After a pipe has been created and enabled successfully, the Pipe data can be
+exchanged between the host-pep and remote-pep (modem).
+
 Authors
 -------
...	...	@@ -182,6 +182,59 @@
182	182	or zero if encapsulation is off.
183	183
184	184
	185	+Phonet Pipe-controller Implementation
	186	+-------------------------------------
	187	+
	188	+Phonet Pipe-controller is enabled by selecting the CONFIG_PHONET_PIPECTRLR Kconfig
	189	+option. It is useful when communicating with those Nokia Modems which do not
	190	+implement Pipe controller in them e.g. Nokia Slim Modem used in ST-Ericsson
	191	+U8500 platform.
	192	+
	193	+The implementation is based on the Data Connection Establishment Sequence
	194	+depicted in 'Nokia Wireless Modem API - Wireless_modem_user_guide.pdf'
	195	+document.
	196	+
	197	+It allows a phonet sequenced socket (host-pep) to initiate a Pipe connection
	198	+between itself and a remote pipe-end point (e.g. modem).
	199	+
	200	+The implementation adds socket options at SOL_PNPIPE level:
	201	+
	202	+ PNPIPE_CREATE
	203	+ It accepts an integer argument where-in
	204	+ lower order 16 bits: pn_dev and pn_port pair for remote pep.
	205	+ higher order 16 bits: 8 bit pipe-handle
	206	+
	207	+ It sends a PNS_PEP_CONNECT_REQ on sequenced socket itself. On getting
	208	+ PNS_PEP_CONNECT_RESP, it sends PNS_PEP_CONNECT_REQ to remote pep. On
	209	+ getting response from remote pep, it selects the best possible Flow
	210	+ control mechanism supported by remote-pep (modem) and then it sends
	211	+ PNS_PEP_CREATED_IND to the sequenced socket and to the remote pep.
	212	+
	213	+ It then updates the pipe state associated with the sequenced socket to
	214	+ be PIPE_DISABLED.
	215	+
	216	+ PNPIPE_ENABLE
	217	+ It follows the same sequence as above for enabling a pipe by sending
	218	+ PNS_PEP_ENABLE_REQ initially and then sending PNS_PEP_ENABLED_IND after
	219	+ getting responses from sequenced socket and remote-pep.
	220	+ It will also update the pipe state associated with the sequenced socket
	221	+ to PIPE_ENABLED.
	222	+
	223	+ PNPIPE_DESTROY
	224	+ This will send out PNS_PEP_DISCONNECT_REQ on the sequenced socket and
	225	+ the remote pep.
	226	+ It will also update the pipe state associated with the sequenced socket
	227	+ to PIPE_IDLE
	228	+
	229	+ PNPIPE_INQ
	230	+ This getsocktopt allows the user-space running on the sequenced socket
	231	+ to examine the pipe state associated with that socket ie. whether the
	232	+ pipe is created (PIPE_DISABLED) or enabled (PIPE_ENABLED) or disabled
	233	+ (PIPE_DISABLED) or no pipe exists (PIPE_IDLE).
	234	+
	235	+After a pipe has been created and enabled successfully, the Pipe data can be
	236	+exchanged between the host-pep and remote-pep (modem).
	237	+
185	238	Authors
186	239	-------
187	240