Commit Graph

9 Commits

Author SHA1 Message Date
Damien George
0f6f86ca49 stm32/usbd_cdc_interface: Refactor USB CDC tx code to not use SOF IRQ.
Prior to this commit the USB CDC used the USB start-of-frame (SOF) IRQ to
regularly check if buffered data needed to be sent out to the USB host.
This wasted resources (CPU, power) if no data needed to be sent.

This commit changes how the USB CDC transmits buffered data:
- When new data is first available to send the data is queued immediately
  on the USB IN endpoint, ready to be sent as soon as possible.
- Subsequent additions to the buffer (via usbd_cdc_try_tx()) will wait.
- When the low-level USB driver has finished sending out the data queued
  in the USB IN endpoint it calls usbd_cdc_tx_ready() which immediately
  queues any outstanding data, waiting for the next IN frame.

The benefits on this new approach are:
- SOF IRQ does not need to run continuously so device has a better chance
  to sleep for longer, and be more responsive to other IRQs.
- Because SOF IRQ is off, current consumption is reduced by a small amount,
  roughly 200uA when USB is connected (measured on PYBv1.0).
- CDC tx throughput (USB IN) on PYBv1.0 is about 2.3 faster (USB OUT is
  unchanged).
- When USB is connected, Python code that is executing is slightly faster
  because SOF IRQ no longer interrupts continuously.
- On F733 with USB HS, CDC tx throughput is about the same as prior to this
  commit.
- On F733 with USB HS, Python code is about 5% faster because of no SOF.

As part of this refactor, the serial port should no longer echo initial
characters when the serial port is first opened (this only used to happen
rarely on USB FS, but on USB HS is was more evident).
2018-10-15 15:37:01 +11:00
Damien George
47ecbbbecb stm32/usb: Add ability to have 2x VCP interfaces on the one USB device.
This patch adds the configuration MICROPY_HW_USB_ENABLE_CDC2 which enables
a new USB device configuration at runtime: VCP+VCP+MSC.  It will give two
independent VCP interfaces available via pyb.USB_VCP(0) and pyb.USB_VCP(1).
The first one is the usual one and has the REPL on it.  The second one is
available for general use.

This configuration is disabled by default because if the mode is not used
then it takes up about 2200 bytes of RAM.  Also, F4 MCUs can't support this
mode on their USB FS peripheral (eg PYBv1.x) because they don't have enough
endpoints.  The USB HS peripheral of an F4 supports it, as well as both the
USB FS and USB HS peripherals of F7 MCUs.
2018-05-14 23:44:45 +10:00
Damien George
bf08a99ccd stm32/usb: Combine CDC lower-layer and interface state into one struct. 2018-05-14 16:15:58 +10:00
Damien George
d966a33486 stm32: Change header include guards from STMHAL to STM32 to match dir. 2018-02-15 15:47:04 +11:00
Damien George
db702ba722 stm32/usbdev: Add support for high-speed USB device mode.
This patch adds support in the USBD configuration and CDC-MSC-HID class for
high-speed USB mode.  To enable it the board configuration must define
USE_USB_HS, and either not define USE_USB_HS_IN_FS, or be an STM32F723 or
STM32F733 MCU which have a built-in HS PHY.  High-speed mode is then
selected dynamically by passing "high_speed=True" to the pyb.usb_mode()
function, otherwise it defaults to full-speed mode.

This patch has been tested on an STM32F733.
2018-02-01 17:57:44 +11:00
Li Weiwei
e39fcda8eb stm32/usbd_cdc_interface.h: Fix code comments after recent refactor. 2017-10-13 12:45:16 +11:00
Damien George
f8f17f48c5 stm32/usbdev: Put all state for the USB device driver in a struct. 2017-09-21 21:51:04 +10:00
Damien George
980b33177b stm32/usbdev: Put all CDC state in a struct. 2017-09-21 21:48:28 +10:00
Damien George
01dd7804b8 ports: Make new ports/ sub-directory and move all ports there.
This is to keep the top-level directory clean, to make it clear what is
core and what is a port, and to allow the repository to grow with new ports
in a sustainable way.
2017-09-06 13:40:51 +10:00