mbed-os/platform/USBPhy.h

302 lines
9.9 KiB
C++

/* mbed Microcontroller Library
* Copyright (c) 2018-2018 ARM Limited
*
* 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
* * Any endpoint configurations which fit in the parameters of the table returned
* by USBPhy::endpoint_table can be used.
* * All endpoints in any valid endpoint configuration can be used concurrently
* * Device supports use of at least one control, bulk, interrupt and
* isochronous in each direction at the same time - at least 8 endpoints.
* * Device supports all standard endpoint sizes (wMaxPacketSize)
* * Device can handle an interrupt latency of at least 100ms if reset is not being performed and address is not being set
* * USBPhyEvents events are only sent when USBPhy is in the initialized state
* * When unpowered only the USBPhyEvents::power event can be sent
* * On USB reset all endpoints are removed except for endpoint 0
* * USBPhyEvents::out and USBPhyEvents::in events only occur for endpoints which have been added
* * A call to USBPhy::ep0_write results in USBPhyEvents::in getting called if not
* interrupted by a power loss or reset
* * A call to endpoint_read followed by endpoint_read_result results in USBPhyEvents::out getting called if not
* interrupted by a power loss or reset
* * Endpoint 0 naks all transactions aside from setup packets until one
* of ep0_read, ep0_write or ep0_stall has been called
* * Endpoint 0 stall is automatically cleared on reception of a setup packet
*
* # Undefined behavior
* * Calling USBPhy::endpoint_add or USBPhy::endpoint_remove outside of the control requests SetInterface or SetConfiguration
* * 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 USB packets are processed in the correct order when multiple packets are present.
* Typically IN endpoints should be handled before OUT endpoints if both are pending.
* * Setup packets may be resent if there is noise on the USB line. The USBPhy should be able
* to gracefully handle this scenario and respond to the setup packet with an ACK.
* * Bi-directional 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 get re-sent on the next IN phase. More info on this can be
* found in section 8.5.3.3 of the USB spec.
*
* @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;
/**
* Unstall 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 true if data was read false otherwise
*/
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