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USBPhy.h
1 /*
2  * Copyright (c) 2018-2019, Arm Limited and affiliates.
3  * SPDX-License-Identifier: Apache-2.0
4  *
5  * Licensed under the Apache License, Version 2.0 (the "License");
6  * you may not use this file except in compliance with the License.
7  * You may obtain a copy of the License at
8  *
9  * http://www.apache.org/licenses/LICENSE-2.0
10  *
11  * Unless required by applicable law or agreed to in writing, software
12  * distributed under the License is distributed on an "AS IS" BASIS,
13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14  * See the License for the specific language governing permissions and
15  * limitations under the License.
16  */
17 
18 #ifndef USBPHY_H
19 #define USBPHY_H
20 
21 #include "USBPhyTypes.h"
22 #include "USBPhyEvents.h"
23 
24 /** Abstract interface to physical USB hardware
25  *
26  * # Defined behavior
27  * * You can use any endpoint configurations that fit in the parameters
28  * of the table returned by USBPhy::endpoint_table.
29  * * You can use all endpoints in any valid endpoint configuration concurrently.
30  * * The device supports use of at least one control, bulk, interrupt and
31  * isochronous in each direction at the same time - at least 8 endpoints.
32  * * USBPhy supports all standard endpoint sizes (wMaxPacketSize).
33  * * USBPhy can handle an interrupt latency of at least 100ms if the host PC
34  * is not performing a reset or setting the device's address.
35  * * USBPhy only sends USBPhyEvents when it is in the initialized state.
36  * * When unpowered, USBPhy only sends the USBPhyEvents::power event.
37  * * On USB reset, all endpoints are removed except for endpoint 0.
38  * * A call to USBPhy::ep0_write results in the call of USBPhyEvents::in when
39  * the PC reads the data unless a power loss, reset, or a call to
40  * USBPhy::disconnect occurs first.
41  * * A call to USBPhy::endpoint_write results in the call of USBPhyEvents::in
42  * when the pc reads the data unless a power loss, reset, or a call to
43  * USBPhy::endpoint_abort occurs first.
44  * * A call to USBPhy::endpoint_read results in the call of USBPhyEvents::out
45  * when the pc sends data unless a power loss, reset, or a call to
46  * USBPhy::endpoint_abort occurs first.
47  * * Endpoint 0 naks all transactions aside from setup packets until
48  * higher-level code calls one of USBPhy::ep0_read, USBPhy::ep0_write or
49  * USBPhy::ep0_stall.
50  * * Endpoint 0 stall automatically clears on reception of a setup packet.
51  *
52  * # Undefined behavior
53  * * Calling USBPhy::endpoint_add or USBPhy::endpoint_remove outside of the
54  * control requests SetInterface or SetConfiguration.
55  * * Calling USBPhy::endpoint_remove on an endpoint that has an ongoing read
56  * or write operation. To avoid undefined behavior, you must abort ongoing
57  * operations with USBPhy::endpoint_abort.
58  * * Devices behavior is undefined if latency is greater than 2ms when address
59  * is being set - see USB spec 9.2.6.3.
60  * * Devices behavior is undefined if latency is greater than 10ms when a
61  * reset occurs - see USB spec 7.1.7.5.
62  * * Calling any of the USBPhy::endpoint_* functions on endpoint 0.
63  *
64  * # Notes
65  * * Make sure USBPhy sends USBPhyEvents in the correct order when multiple
66  * packets are present. USBPhy must send IN endpoint events before OUT
67  * endpoint events if both are pending.
68  * * A host PC may resend setup packets to a USB device if there is noise on
69  * the USB line. The USBPhy should be able to handle this scenario and
70  * respond to the setup packet with an ACK.
71  * * Bidirectional protocols making use of alternating IN and OUT phases
72  * should not rely on the last ACK an IN transfer to indicate that the
73  * OUT phase should start. Instead, the OUT phase should be started at
74  * the same time the last IN transfer is started. This is because the ACK
75  * to the last in transfer may be dropped if there is noise on the USB
76  * line. If dropped, it will only be resent on the next IN phase. You can
77  * find more information on this in section 8.5.3.3 of the USB
78  * specification.
79  *
80  * @ingroup usb_device_core
81  */
82 class USBPhy {
83 public:
84  USBPhy() {};
85  virtual ~USBPhy() {};
86 
87  /**
88  * Initialize this USBPhy instance
89  *
90  * This function must be called before calling
91  * any other functions of this class, unless specifically
92  * noted.
93  *
94  * @param events Callback class to handle USB events
95  */
96  virtual void init(USBPhyEvents *events) = 0;
97 
98  /**
99  * Power down this USBPhy instance
100  *
101  * Disable interrupts and stop sending events.
102  */
103  virtual void deinit() = 0;
104 
105  /**
106  * Check if USB power is present
107  *
108  * Devices which don't support checking the USB power state
109  * must always return true.
110  *
111  * @return true if USB power is present, false otherwise
112  */
113  virtual bool powered() = 0;
114 
115  /**
116  * Make the USB phy visible to the USB host
117  *
118  * Enable either the D+ or D- pullup so the host can detect
119  * the presence of this device.
120  */
121  virtual void connect() = 0;
122 
123  /**
124  * Detach the USB phy
125  *
126  * Disable the D+ and D- pullup and stop responding to
127  * USB traffic.
128  */
129  virtual void disconnect() = 0;
130 
131  /**
132  * Set this device to the configured state
133  *
134  * Enable added endpoints if they are not enabled
135  * already.
136  */
137  virtual void configure() = 0;
138 
139  /**
140  * Leave the configured state
141  *
142  * This is a notification to the USBPhy indicating that the device
143  * is leaving the configured state. The USBPhy can disable all
144  * endpoints other than endpoint 0.
145  *
146  */
147  virtual void unconfigure() = 0;
148 
149  /**
150  * Enable the start of frame interrupt
151  *
152  * Call USBPhyEvents::sof on every frame.
153  */
154  virtual void sof_enable() = 0;
155 
156  /**
157  * Disable the start of frame interrupt
158  *
159  * Stop calling USBPhyEvents::sof.
160  */
161  virtual void sof_disable() = 0;
162 
163  /**
164  * Set the USBPhy's address
165  *
166  * @param address This device's USB address
167  */
168  virtual void set_address(uint8_t address) = 0;
169 
170  /**
171  * Wake upstream devices
172  */
173  virtual void remote_wakeup() = 0;
174 
175  /**
176  * Get the endpoint table
177  *
178  * This function returns a table which describes the endpoints
179  * can be used, the functionality of those endpoints and the
180  * resource cost.
181  */
182  virtual const usb_ep_table_t *endpoint_table() = 0;
183 
184  /**
185  * Set wMaxPacketSize of endpoint 0
186  *
187  * @param max_packet The wMaxPacketSize value for endpoint 0
188  * @return The actual size of endpoint 0
189  */
190  virtual uint32_t ep0_set_max_packet(uint32_t max_packet) = 0;
191 
192  /**
193  * Read the contents of the SETUP packet
194  *
195  * @param buffer Buffer to fill with data
196  * @param size Size of buffer passed in
197  */
198  virtual void ep0_setup_read_result(uint8_t *buffer, uint32_t size) = 0;
199 
200  /**
201  * Start receiving a packet of up to wMaxPacketSize on endpoint 0
202  *
203  * @param data Buffer to fill with the data read
204  * @param size Size of buffer
205  */
206  virtual void ep0_read(uint8_t *data, uint32_t size) = 0;
207 
208  /**
209  * Read the contents of a received packet
210  *
211  * @return Size of data read
212  */
213  virtual uint32_t ep0_read_result() = 0;
214 
215  /**
216  * Write a packet on endpoint 0
217  *
218  * @param buffer Buffer fill with data to send
219  * @param size Size of data to send
220  */
221  virtual void ep0_write(uint8_t *buffer, uint32_t size) = 0;
222 
223  /**
224  * Protocol stall on endpoint 0
225  *
226  * Stall all IN and OUT packets on endpoint 0 until a setup packet
227  * is received.
228  * @note The stall is cleared automatically when a setup packet is received
229  */
230  virtual void ep0_stall() = 0;
231 
232  /**
233  * Configure and enable an endpoint
234  *
235  * @param endpoint Endpoint to configure and enable
236  * @param max_packet The maximum packet size that can be sent or received
237  * @param type The type of endpoint this should be configured as -
238  * USB_EP_TYPE_BULK, USB_EP_TYPE_INT or USB_EP_TYPE_ISO
239  * @note This function cannot be used to configure endpoint 0. That must be done
240  * with ep0_set_max_packet
241  */
242  virtual bool endpoint_add(usb_ep_t endpoint, uint32_t max_packet, usb_ep_type_t type) = 0;
243 
244  /**
245  * Disable an endpoint
246  *
247  * @param endpoint Endpoint to disable
248  */
249  virtual void endpoint_remove(usb_ep_t endpoint) = 0;
250 
251  /**
252  * Perform a functional stall on the given endpoint
253  *
254  * Set the HALT feature for this endpoint so that all further
255  * communication is aborted.
256  *
257  * @param endpoint Endpoint to stall
258  */
259  virtual void endpoint_stall(usb_ep_t endpoint) = 0;
260 
261  /**
262  * Un-stall the endpoint
263  *
264  * Clear the HALT feature on this endpoint so communication can
265  * resume.
266  *
267  * @param endpoint Endpoint to stall
268  */
269  virtual void endpoint_unstall(usb_ep_t endpoint) = 0;
270 
271  /**
272  * Start a read on the given endpoint
273  *
274  * @param endpoint Endpoint to start the read on
275  * @param data Buffer to fill with data
276  * @param size Size of the read buffer. This must be at least
277  * the max packet size for this endpoint.
278  * @return true if the read was successfully started, false otherwise
279  */
280  virtual bool endpoint_read(usb_ep_t endpoint, uint8_t *data, uint32_t size) = 0;
281 
282  /**
283  * Finish a read on the given endpoint
284  *
285  * @param endpoint Endpoint to check
286  * @return The number of bytes received
287  */
288  virtual uint32_t endpoint_read_result(usb_ep_t endpoint) = 0;
289 
290  /**
291  * Start a write on the given endpoint
292  *
293  * @param endpoint Endpoint to write to
294  * @param data Buffer to write
295  * @param size Size of data to write
296  * @return true if the data was prepared for transmit, false otherwise
297  */
298  virtual bool endpoint_write(usb_ep_t endpoint, uint8_t *data, uint32_t size) = 0;
299 
300  /**
301  * Abort the current transfer if it has not yet been sent
302  *
303  * @param endpoint Endpoint to abort the transfer on. It is implementation defined
304  * if this function has an effect on receive endpoints.
305  */
306  virtual void endpoint_abort(usb_ep_t endpoint) = 0;
307 
308  /**
309  * Callback used for performing USB processing
310  *
311  * USBPhy processing should be triggered by calling USBPhyEvents::start_process
312  * and done inside process. All USBPhyEvents callbacks aside from
313  * USBPhyEvents::start_process must be called in the context of process
314  */
315  virtual void process() = 0;
316 };
317 
318 #endif
virtual void sof_disable()=0
Disable the start of frame interrupt.
virtual void ep0_setup_read_result(uint8_t *buffer, uint32_t size)=0
Read the contents of the SETUP packet.
virtual uint32_t ep0_read_result()=0
Read the contents of a received packet.
virtual void connect()=0
Make the USB phy visible to the USB host.
virtual uint32_t endpoint_read_result(usb_ep_t endpoint)=0
Finish a read on the given endpoint.
virtual void process()=0
Callback used for performing USB processing.
virtual void endpoint_stall(usb_ep_t endpoint)=0
Perform a functional stall on the given endpoint.
virtual void remote_wakeup()=0
Wake upstream devices.
virtual bool endpoint_write(usb_ep_t endpoint, uint8_t *data, uint32_t size)=0
Start a write on the given endpoint.
virtual void ep0_write(uint8_t *buffer, uint32_t size)=0
Write a packet on endpoint 0.
virtual bool endpoint_add(usb_ep_t endpoint, uint32_t max_packet, usb_ep_type_t type)=0
Configure and enable an endpoint.
Abstract interface to physical USB hardware.
Definition: USBPhy.h:82
virtual const usb_ep_table_t * endpoint_table()=0
Get the endpoint table.
virtual void disconnect()=0
Detach the USB phy.
virtual void sof_enable()=0
Enable the start of frame interrupt.
virtual void configure()=0
Set this device to the configured state.
virtual void init(USBPhyEvents *events)=0
Initialize this USBPhy instance.
virtual void ep0_stall()=0
Protocol stall on endpoint 0.
virtual void endpoint_unstall(usb_ep_t endpoint)=0
Un-stall the endpoint.
virtual void ep0_read(uint8_t *data, uint32_t size)=0
Start receiving a packet of up to wMaxPacketSize on endpoint 0.
virtual void endpoint_remove(usb_ep_t endpoint)=0
Disable an endpoint.
virtual void deinit()=0
Power down this USBPhy instance.
virtual void endpoint_abort(usb_ep_t endpoint)=0
Abort the current transfer if it has not yet been sent.
virtual bool powered()=0
Check if USB power is present.
virtual uint32_t ep0_set_max_packet(uint32_t max_packet)=0
Set wMaxPacketSize of endpoint 0.
virtual void unconfigure()=0
Leave the configured state.
Event handler for USBPhy.
Definition: USBPhyEvents.h:31
virtual void set_address(uint8_t address)=0
Set the USBPhy's address.
virtual bool endpoint_read(usb_ep_t endpoint, uint8_t *data, uint32_t size)=0
Start a read on the given endpoint.
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