At an interrupt barrier, the host must be able to ensure that no
interrupt generated before reaching the barrier is still pending and
will be delivered after crossing the barrier.
For this, we introduce the following concept:
- interrupts have a serial number. This number is sent to the host
on EP 1 (currently bulk) to signal the interrupt, instead of the
zero byte we used previously.
- the new request ATUSB_SPI_WRITE2_SYNC returns the interrupt
serial number from after the register write (the register write
itself is the interrupt barrier).
- the host can now check if the serial indicated from bulk and the
serial from ATUSB_SPI_WRITE2_SYNC are the same. If yes, interrupts
are synchronized. If not, it has to wait for the interrupt to be
signaled on EP 1.
We should also consider the case that the interrupt serial has gotten
ahead of ATUSB_SPI_WRITE2_SYNC. But that seems to happen rarely. In
any case, it's something for the host driver to worry about, not for
the firmware.
- board.h (irq_serial), board_app.c (irq_serial, INT0_vect): count
the interrupt serial number and return it when signaling the
interrupt
- include/atusb/ep0.h (ATUSB_SPI_WRITE2_SYNC), ep0.c (my_setup):
new request ATUSB_SPI_WRITE2_SYNC that does a register write, then
returns the interrupt serial
This reverts commit 39e3d4e61a.
The log isn't so useful in its present state because we may have to
unplug/replug to get out of a troublesome condition.
- board.h (gpio_cleanup), board_app.c (gpio_cleanup): restore INT0
when done manipulating GPIOs
- board.c (gpio): updated comment explaining how to restore INT0
- include/atusb/ep0.h (enum atspi_requests), ep0.c
(ATUSB_GPIO_CLEANUP): new request to return to normal operation
after ATUSB_GPIO
- ep0.c (setup_request): store combined request code in "req", for
later reuse
- include/ep0.h (ATUSB_SPI_WRITE, ATUSB_SPI_READ1, ATUSB_SPI_READ2),
ep0.c (setup_request): new requests that translate easily into
general SPI operations
This allows us to do other things as well, e.g., change state.
- ep0.c (ep0_init), usb/dfu.c (dfu_init): use user_setup
- usb/atu2.c (usb_poll): no need to reset user_setup - the user's
reset function can do that
- usb/usb.h (user_setups), usb/usb.c (handle_setup): removed
user_setups
- usb/usb.h (user_set_interface), usb/usb.c (user_set_interface,
handle_setup): callback for SET_INTERFACE
- ep0.c (ep0_init), usb/dfu.c (dfu_init): set user_setups[0] instead
of user_setup
- usb/atu2.c (usb_poll): reset user_setup on bus reset
- usb/usb.h (user_setups), usb/usb.c (user_setups): array of
interface-specific setup functions
- usb/usb.c (handle_setup): in SET_INTERFACE, select setup function
from user_setups according to interface
- usb/usb.c (handle_setup): if user_setup is not set (e.g., the
optional SET_INTERFACE was never issued), fall back to user_setups[0]
reset_rf now resets all GPIOs to their default state. This way, we
can easily recover from an incomplete or incorrect use of ATUSB_GPIO.
- atusb.c (main), board.c (reset_rf): moved call to spi_init into
reset_rf
- board.c (reset_rf, board_init): moved GPIO setup to reset_rf
- board.c (reset_rf): set GPIOs to reset defaults
- board.h (gpio), board.c: read/modify/write all settings of GPIO
ports
- include/atusb/ep0.h (enum atspi_requests): added new request
ATUSB_GPIO
- ep0.c (my_setup): ATUSB_GPIO reads/reconfigures a GPIO port
- ep0.c (my_setup): ATUSB_SRAM_READ is FROM_DEV, not TO_DEV
- ep0.c (my_setup): in ATUSB_SRAM_READ, write setup->wLength bytes,
not "size" (which is uninitialized)
- atusb.c (main): poll the 16 bit timer for overflows
- board.h (timer_poll, timer_read), (board.c (timer_h, timer_poll,
timer_read, board_init): added support for a free-running 48 bit timer
(16 bits in hardware, 32 bits in software)
- include/atusb/ep0.h (ATUSB_TIMER), ep0.c (my_setup): new request
ATUSB_TIMER to retrieve the value of the 8 MHz counter
- include/atusb/ep0.h (enum atspi_requests): describe what the groups
of requests do
- board.c (board_init): disable the watchdog timer (tricky !)
- board.h (reset_cpu), board.c: enable the watchdog timer to cause a
CPU reset
- ep0.c (my_setup): uncommented and updated ATUSB_RESET handler
