Mbed OS Reference | USBPhy.h Source File

 /*
  * Copyright (c) 2018-2019, Arm Limited and affiliates.
  * SPDX-License-Identifier: Apache-2.0
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
 
 #ifndef USBPHY_H
 #define USBPHY_H
 
 #include "USBPhyTypes.h"
 #include "USBPhyEvents.h"
 
 /** Abstract interface to physical USB hardware
  *
  * # Defined behavior
  * * You can use any endpoint configurations that fit in the parameters
  *      of the table returned by USBPhy::endpoint_table.
  * * You can use all endpoints in any valid endpoint configuration concurrently.
  * * The device supports use of at least one control, bulk, interrupt and
  *      isochronous in each direction at the same time - at least 8 endpoints.
  * * USBPhy supports all standard endpoint sizes (wMaxPacketSize).
  * * USBPhy can handle an interrupt latency of at least 100ms if the host PC
  *      is not performing a reset or setting the device's address.
  * * USBPhy only sends USBPhyEvents when it is in the initialized state.
  * * When unpowered, USBPhy only sends the USBPhyEvents::power event.
  * * On USB reset, all endpoints are removed except for endpoint 0.
  * * A call to USBPhy::ep0_write results in the call of USBPhyEvents::in when
  *      the PC reads the data unless a power loss, reset, or a call to
  *      USBPhy::disconnect occurs first.
  * * A call to USBPhy::endpoint_write results in the call of USBPhyEvents::in
  *      when the pc reads the data unless a power loss, reset, or a call to
  *      USBPhy::endpoint_abort occurs first.
  * * A call to USBPhy::endpoint_read results in the call of USBPhyEvents::out
  *      when the pc sends data unless a power loss, reset, or a call to
  *      USBPhy::endpoint_abort occurs first.
  * * Endpoint 0 naks all transactions aside from setup packets until
  *      higher-level code calls one of USBPhy::ep0_read, USBPhy::ep0_write or
  *      USBPhy::ep0_stall.
  * * Endpoint 0 stall automatically clears on reception of a setup packet.
  *
  * # Undefined behavior
  * * Calling USBPhy::endpoint_add or USBPhy::endpoint_remove outside of the
  *      control requests SetInterface or SetConfiguration.
  * * Calling USBPhy::endpoint_remove on an endpoint that has an ongoing read
  *      or write operation. To avoid undefined behavior, you must abort ongoing
  *      operations with USBPhy::endpoint_abort.
  * * Devices behavior is undefined if latency is greater than 2ms when address
  *      is being set - see USB spec 9.2.6.3.
  * * Devices behavior is undefined if latency is greater than 10ms when a
  *      reset occurs - see USB spec 7.1.7.5.
  * * Calling any of the USBPhy::endpoint_* functions on endpoint 0.
  *
  * # Notes
  * * Make sure USBPhy sends USBPhyEvents in the correct order when multiple
  *      packets are present. USBPhy must send IN endpoint events before OUT
  *      endpoint events if both are pending.
  * * A host PC may resend setup packets to a USB device if there is noise on
  *      the USB line. The USBPhy should be able to handle this scenario and
  *      respond to the setup packet with an ACK.
  * * Bidirectional protocols making use of alternating IN and OUT phases
  *      should not rely on the last ACK an IN transfer to indicate that the
  *      OUT phase should start. Instead, the OUT phase should be started at
  *      the same time the last IN transfer is started. This is because the ACK
  *      to the last in transfer may be dropped if there is noise on the USB
  *      line. If dropped, it will only be resent on the next IN phase. You can
  *      find more information on this in section 8.5.3.3 of the USB
  *      specification.
  *
  * @ingroup usb_device_core
  */
 class USBPhy {
 public:
     USBPhy() {};
     virtual ~USBPhy() {};
 
     /**
      * Initialize this USBPhy instance
      *
      * This function must be called before calling
      * any other functions of this class, unless specifically
      * noted.
      *
      * @param events Callback class to handle USB events
      */
     virtual void init(USBPhyEvents *events) = 0;
 
     /**
      * Power down this USBPhy instance
      *
      * Disable interrupts and stop sending events.
      */
     virtual void deinit() = 0;
 
     /**
      * Check if USB power is present
      *
      * Devices which don't support checking the USB power state
      * must always return true.
      *
      * @return true if USB power is present, false otherwise
      */
     virtual bool powered() = 0;
 
     /**
      * Make the USB phy visible to the USB host
      *
      * Enable either the D+ or D-  pullup so the host can detect
      * the presence of this device.
      */
     virtual void connect() = 0;
 
     /**
      * Detach the USB phy
      *
      * Disable the D+ and D- pullup and stop responding to
      * USB traffic.
      */
     virtual void disconnect() = 0;
 
     /**
      * Set this device to the configured state
      *
      * Enable added endpoints if they are not enabled
      * already.
      */
     virtual void configure() = 0;
 
     /**
      * Leave the configured state
      *
      * This is a notification to the USBPhy indicating that the device
      * is leaving the configured state. The USBPhy can disable all
      * endpoints other than endpoint 0.
      *
      */
     virtual void unconfigure() = 0;
 
     /**
      * Enable the start of frame interrupt
      *
      * Call USBPhyEvents::sof on every frame.
      */
     virtual void sof_enable() = 0;
 
     /**
      * Disable the start of frame interrupt
      *
      * Stop calling USBPhyEvents::sof.
      */
     virtual void sof_disable() = 0;
 
     /**
      * Set the USBPhy's address
      *
      * @param address This device's USB address
      */
     virtual void set_address(uint8_t address) = 0;
 
     /**
      * Wake upstream devices
      */
     virtual void remote_wakeup() = 0;
 
     /**
      * Get the endpoint table
      *
      * This function returns a table which describes the endpoints
      * can be used, the functionality of those endpoints and the
      * resource cost.
      */
     virtual const usb_ep_table_t *endpoint_table() = 0;
 
     /**
      * Set wMaxPacketSize of endpoint 0
      *
      * @param max_packet The wMaxPacketSize value for endpoint 0
      * @return The actual size of endpoint 0
      */
     virtual uint32_t ep0_set_max_packet(uint32_t max_packet) = 0;
 
     /**
      * Read the contents of the SETUP packet
      *
      * @param buffer Buffer to fill with data
      * @param size Size of buffer passed in
      */
     virtual void ep0_setup_read_result(uint8_t *buffer, uint32_t size) = 0;
 
     /**
      * Start receiving a packet of up to wMaxPacketSize on endpoint 0
      *
      * @param data Buffer to fill with the data read
      * @param size Size of buffer
      */
     virtual void ep0_read(uint8_t *data, uint32_t size) = 0;
 
     /**
      * Read the contents of a received packet
      *
      * @return Size of data read
      */
     virtual uint32_t ep0_read_result() = 0;
 
     /**
      * Write a packet on endpoint 0
      *
      * @param buffer Buffer fill with data to send
      * @param size Size of data to send
      */
     virtual void ep0_write(uint8_t *buffer, uint32_t size) = 0;
 
     /**
      * Protocol stall on endpoint 0
      *
      * Stall all IN and OUT packets on endpoint 0 until a setup packet
      * is received.
      * @note The stall is cleared automatically when a setup packet is received
      */
     virtual void ep0_stall() = 0;
 
     /**
      * Configure and enable an endpoint
      *
      * @param endpoint Endpoint to configure and enable
      * @param max_packet The maximum packet size that can be sent or received
      * @param type The type of endpoint this should be configured as -
      *  USB_EP_TYPE_BULK, USB_EP_TYPE_INT or USB_EP_TYPE_ISO
      * @note This function cannot be used to configure endpoint 0. That must be done
      * with ep0_set_max_packet
      */
     virtual bool endpoint_add(usb_ep_t endpoint, uint32_t max_packet, usb_ep_type_t type) = 0;
 
     /**
      * Disable an endpoint
      *
      * @param endpoint Endpoint to disable
      */
     virtual void endpoint_remove(usb_ep_t endpoint) = 0;
 
     /**
      * Perform a functional stall on the given endpoint
      *
      * Set the HALT feature for this endpoint so that all further
      * communication is aborted.
      *
      * @param endpoint Endpoint to stall
      */
     virtual void endpoint_stall(usb_ep_t endpoint) = 0;
 
     /**
      * Un-stall the endpoint
      *
      * Clear the HALT feature on this endpoint so communication can
      * resume.
      *
      * @param endpoint Endpoint to stall
      */
     virtual void endpoint_unstall(usb_ep_t endpoint) = 0;
 
     /**
      * Start a read on the given endpoint
      *
      * @param endpoint Endpoint to start the read on
      * @param data Buffer to fill with data
      * @param size Size of the read buffer. This must be at least
      *     the max packet size for this endpoint.
      * @return true if the read was successfully started, false otherwise
      */
     virtual bool endpoint_read(usb_ep_t endpoint, uint8_t *data, uint32_t size) = 0;
 
     /**
      * Finish a read on the given endpoint
      *
      * @param endpoint Endpoint to check
      * @return The number of bytes received
      */
     virtual uint32_t endpoint_read_result(usb_ep_t endpoint) = 0;
 
     /**
      * Start a write on the given endpoint
      *
      * @param endpoint Endpoint to write to
      * @param data Buffer to write
      * @param size Size of data to write
      * @return true if the data was prepared for transmit, false otherwise
      */
     virtual bool endpoint_write(usb_ep_t endpoint, uint8_t *data, uint32_t size) = 0;
 
     /**
      * Abort the current transfer if it has not yet been sent
      *
      * @param endpoint Endpoint to abort the transfer on. It is implementation defined
      * if this function has an effect on receive endpoints.
      */
     virtual void endpoint_abort(usb_ep_t endpoint) = 0;
 
     /**
      * Callback used for performing USB processing
      *
      * USBPhy processing should be triggered by calling USBPhyEvents::start_process
      * and done inside process. All USBPhyEvents callbacks aside from
      * USBPhyEvents::start_process must be called in the context of process
      */
     virtual void process() = 0;
 };
 
 #endif
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