1# Copyright (c) 2022 Renesas Electronics Corporation 2# SPDX-License-Identifier: Apache-2.0 3 4description: Renesas SmartBond USB device controller 5 6compatible: "renesas,smartbond-usbd" 7 8include: usb-controller.yaml 9 10properties: 11 dma-min-transfer-size: 12 type: int 13 description: | 14 Minimum transfer size required to engage DMA. 15 16 ep-out-buf-size: 17 type: array 18 required: true 19 description: | 20 Buffer size for OUT end points 0-3. 21 22 fifo-read-threshold: 23 type: int 24 description: | 25 RX FIFO is 64 bytes. When endpoint size is greater then 64, 26 FIFO warning interrupt is enabled to allow read incoming data 27 during frame reception. 28 It is possible to stay in interrupt reading whole packet at once, 29 but it may be more efficient for MCU to read as much data as 30 possible and when FIFO is hardly filled exit interrupt handler 31 waiting for next FIFO warning level interrupt or packet end. 32 When running at 96MHz code that reads FIFO based on number of 33 bytes stored in USB_RXSx_REG.USB_RXCOUNT takes enough time to 34 fill FIFO with two additional bytes. 35 Settings this threshold above this allows to leave interrupt 36 handler and wait for more bytes before next ISR. This allows 37 reduce overall ISR time to 1/3 of time that would be needed 38 if ISR read as fast as possible. 39 40 iso-out-mps: 41 type: int 42 description: | 43 Max packet size for ISO out endpoint 44
