1 /*
2  *  Copyright (c) 2018, The OpenThread Authors.
3  *  All rights reserved.
4  *
5  *  Redistribution and use in source and binary forms, with or without
6  *  modification, are permitted provided that the following conditions are met:
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8  *     notice, this list of conditions and the following disclaimer.
9  *  2. Redistributions in binary form must reproduce the above copyright
10  *     notice, this list of conditions and the following disclaimer in the
11  *     documentation and/or other materials provided with the distribution.
12  *  3. Neither the name of the copyright holder nor the
13  *     names of its contributors may be used to endorse or promote products
14  *     derived from this software without specific prior written permission.
15  *
16  *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
17  *  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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20  *  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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27  */
28 
29 /**
30  * @file
31  *   This file includes definitions for the HDLC interface to radio (RCP).
32  */
33 
34 #ifndef POSIX_APP_HDLC_INTERFACE_HPP_
35 #define POSIX_APP_HDLC_INTERFACE_HPP_
36 
37 #include "openthread-posix-config.h"
38 #include "platform-posix.h"
39 #include "lib/hdlc/hdlc.hpp"
40 #include "lib/spinel/openthread-spinel-config.h"
41 #include "lib/spinel/spinel_interface.hpp"
42 
43 #if OPENTHREAD_POSIX_CONFIG_RCP_BUS == OT_POSIX_RCP_BUS_UART
44 
45 namespace ot {
46 namespace Posix {
47 
48 /**
49  * This class defines an HDLC interface to the Radio Co-processor (RCP)
50  *
51  */
52 class HdlcInterface
53 {
54 public:
55     /**
56      * This constructor initializes the object.
57      *
58      * @param[in] aCallback         Callback on frame received
59      * @param[in] aCallbackContext  Callback context
60      * @param[in] aFrameBuffer      A reference to a `RxFrameBuffer` object.
61      *
62      */
63     HdlcInterface(Spinel::SpinelInterface::ReceiveFrameCallback aCallback,
64                   void                                         *aCallbackContext,
65                   Spinel::SpinelInterface::RxFrameBuffer       &aFrameBuffer);
66 
67     /**
68      * This destructor deinitializes the object.
69      *
70      */
71     ~HdlcInterface(void);
72 
73     /**
74      * This method initializes the interface to the Radio Co-processor (RCP)
75      *
76      * @note This method should be called before reading and sending spinel frames to the interface.
77      *
78      * @param[in]  aRadioUrl          RadioUrl parsed from radio url.
79      *
80      * @retval OT_ERROR_NONE          The interface is initialized successfully
81      * @retval OT_ERROR_ALREADY       The interface is already initialized.
82      * @retval OT_ERROR_INVALID_ARGS  The UART device or executable cannot be found or failed to open/run.
83      *
84      */
85     otError Init(const Url::Url &aRadioUrl);
86 
87     /**
88      * This method deinitializes the interface to the RCP.
89      *
90      */
91     void Deinit(void);
92 
93     /**
94      * This method encodes and sends a spinel frame to Radio Co-processor (RCP) over the socket.
95      *
96      * This is blocking call, i.e., if the socket is not writable, this method waits for it to become writable for
97      * up to `kMaxWaitTime` interval.
98      *
99      * @param[in] aFrame     A pointer to buffer containing the spinel frame to send.
100      * @param[in] aLength    The length (number of bytes) in the frame.
101      *
102      * @retval OT_ERROR_NONE     Successfully encoded and sent the spinel frame.
103      * @retval OT_ERROR_NO_BUFS  Insufficient buffer space available to encode the frame.
104      * @retval OT_ERROR_FAILED   Failed to send due to socket not becoming writable within `kMaxWaitTime`.
105      *
106      */
107     otError SendFrame(const uint8_t *aFrame, uint16_t aLength);
108 
109     /**
110      * This method waits for receiving part or all of spinel frame within specified interval.
111      *
112      * @param[in]  aTimeout  The timeout value in microseconds.
113      *
114      * @retval OT_ERROR_NONE             Part or all of spinel frame is received.
115      * @retval OT_ERROR_RESPONSE_TIMEOUT No spinel frame is received within @p aTimeout.
116      *
117      */
118     otError WaitForFrame(uint64_t aTimeoutUs);
119 
120     /**
121      * This method updates the file descriptor sets with file descriptors used by the radio driver.
122      *
123      * @param[in,out]  aReadFdSet   A reference to the read file descriptors.
124      * @param[in,out]  aWriteFdSet  A reference to the write file descriptors.
125      * @param[in,out]  aMaxFd       A reference to the max file descriptor.
126      * @param[in,out]  aTimeout     A reference to the timeout.
127      *
128      */
129     void UpdateFdSet(fd_set &aReadFdSet, fd_set &aWriteFdSet, int &aMaxFd, struct timeval &aTimeout);
130 
131     /**
132      * This method performs radio driver processing.
133      *
134      * @param[in]   aContext        The context containing fd_sets.
135      *
136      */
137     void Process(const RadioProcessContext &aContext);
138 
139 #if OPENTHREAD_POSIX_VIRTUAL_TIME
140     /**
141      * This method process read data (decode the data).
142      *
143      * This method is intended only for virtual time simulation. Its behavior is similar to `Read()` but instead of
144      * reading the data from the radio socket, it uses the given data in @p `aEvent`.
145      *
146      * @param[in] aEvent   The data event.
147      *
148      */
Process(const VirtualTimeEvent & aEvent)149     void Process(const VirtualTimeEvent &aEvent) { Decode(aEvent.mData, aEvent.mDataLength); }
150 #endif
151 
152     /**
153      * This method returns the bus speed between the host and the radio.
154      *
155      * @returns   Bus speed in bits/second.
156      *
157      */
GetBusSpeed(void) const158     uint32_t GetBusSpeed(void) const { return mBaudRate; }
159 
160     /**
161      * This method hardware resets the RCP.
162      *
163      * @retval OT_ERROR_NONE            Successfully reset the RCP.
164      * @retval OT_ERROR_NOT_IMPLEMENT   The hardware reset is not implemented.
165      *
166      */
HardwareReset(void)167     otError HardwareReset(void) { return OT_ERROR_NOT_IMPLEMENTED; }
168 
169     /**
170      * This method returns the RCP interface metrics.
171      *
172      * @returns The RCP interface metrics.
173      *
174      */
GetRcpInterfaceMetrics(void) const175     const otRcpInterfaceMetrics *GetRcpInterfaceMetrics(void) const { return &mInterfaceMetrics; }
176 
177 private:
178     /**
179      * This method is called when RCP is reset to recreate the connection with it.
180      *
181      */
182     otError ResetConnection(void);
183 
184     /**
185      * This method instructs `HdlcInterface` to read and decode data from radio over the socket.
186      *
187      * If a full HDLC frame is decoded while reading data, this method invokes the `HandleReceivedFrame()` (on the
188      * `aCallback` object from constructor) to pass the received frame to be processed.
189      *
190      */
191     void Read(void);
192 
193     /**
194      * This method waits for the socket file descriptor associated with the HDLC interface to become writable within
195      * `kMaxWaitTime` interval.
196      *
197      * @retval OT_ERROR_NONE   Socket is writable.
198      * @retval OT_ERROR_FAILED Socket did not become writable within `kMaxWaitTime`.
199      *
200      */
201     otError WaitForWritable(void);
202 
203     /**
204      * This method writes a given frame to the socket.
205      *
206      * This is blocking call, i.e., if the socket is not writable, this method waits for it to become writable for
207      * up to `kMaxWaitTime` interval.
208      *
209      * @param[in] aFrame  A pointer to buffer containing the frame to write.
210      * @param[in] aLength The length (number of bytes) in the frame.
211      *
212      * @retval OT_ERROR_NONE    Frame was written successfully.
213      * @retval OT_ERROR_FAILED  Failed to write due to socket not becoming writable within `kMaxWaitTime`.
214      *
215      */
216     otError Write(const uint8_t *aFrame, uint16_t aLength);
217 
218     /**
219      * This method performs HDLC decoding on received data.
220      *
221      * If a full HDLC frame is decoded while reading data, this method invokes the `HandleReceivedFrame()` (on the
222      * `aCallback` object from constructor) to pass the received frame to be processed.
223      *
224      * @param[in] aBuffer  A pointer to buffer containing data.
225      * @param[in] aLength  The length (number of bytes) in the buffer.
226      *
227      */
228     void Decode(const uint8_t *aBuffer, uint16_t aLength);
229 
230     static void HandleHdlcFrame(void *aContext, otError aError);
231     void        HandleHdlcFrame(otError aError);
232 
233     /**
234      * This method opens file specified by aRadioUrl.
235      *
236      * @param[in] aRadioUrl  A reference to object containing path to file and data for configuring
237      *                       the connection with tty type file.
238      *
239      * @retval The file descriptor of newly opened file.
240      */
241     int OpenFile(const Url::Url &aRadioUrl);
242 
243     /**
244      * This method closes file associated with the file descriptor.
245      *
246      */
247     void CloseFile(void);
248 
249 #if OPENTHREAD_POSIX_CONFIG_RCP_PTY_ENABLE
250     static int ForkPty(const Url::Url &aRadioUrl);
251 #endif
252 
253     enum
254     {
255         kMaxFrameSize  = Spinel::SpinelInterface::kMaxFrameSize,
256         kMaxWaitTime   = 2000, ///< Maximum wait time in Milliseconds for socket to become writable (see `SendFrame`).
257         kResetTimeout  = 5000, ///< Maximum wait time in Milliseconds for file to become ready (see `ResetConnection`).
258         kOpenFileDelay = 500,  ///< Delay between open file calls, in Milliseconds (see `ResetConnection`).
259         kRemoveRcpDelay =
260             2000, ///< Delay for removing RCP device from host OS after hard reset (see `ResetConnection`).
261     };
262 
263     Spinel::SpinelInterface::ReceiveFrameCallback mReceiveFrameCallback;
264     void                                         *mReceiveFrameContext;
265     Spinel::SpinelInterface::RxFrameBuffer       &mReceiveFrameBuffer;
266 
267     int             mSockFd;
268     uint32_t        mBaudRate;
269     Hdlc::Decoder   mHdlcDecoder;
270     const Url::Url *mRadioUrl;
271 
272     otRcpInterfaceMetrics mInterfaceMetrics;
273 
274     // Non-copyable, intentionally not implemented.
275     HdlcInterface(const HdlcInterface &);
276     HdlcInterface &operator=(const HdlcInterface &);
277 };
278 
279 } // namespace Posix
280 } // namespace ot
281 
282 #endif // OPENTHREAD_POSIX_CONFIG_RCP_BUS == OT_POSIX_RCP_BUS_UART
283 #endif // POSIX_APP_HDLC_INTERFACE_HPP_
284