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| author | Kevin O'Connor <kevin@koconnor.net> | 2019-03-31 13:34:23 -0400 |
|---|---|---|
| committer | Kevin O'Connor <kevin@koconnor.net> | 2019-03-31 13:37:01 -0400 |
| commit | fbbe2cf9d6ced1e1d417464302200414c8ca713a (patch) | |
| tree | d8d48ef8f6919e28fe4fad9b4eb317b45c6679e1 | |
| parent | 60ff2e9dc1eb2c0133bca8ecd9e200a3502e1f92 (diff) | |
| download | kutter-fbbe2cf9d6ced1e1d417464302200414c8ca713a.tar.gz kutter-fbbe2cf9d6ced1e1d417464302200414c8ca713a.tar.xz kutter-fbbe2cf9d6ced1e1d417464302200414c8ca713a.zip | |
lpc176x: Explicitly disconnect USB on a bootloader request
It appears some host machines may not recognize that the USB device
has disconnected upon start of bootloader mode. Explicitly disable
USB and add a 5ms delay to help signal the host of the upcoming
change.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
| -rw-r--r-- | src/lpc176x/usbserial.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/src/lpc176x/usbserial.c b/src/lpc176x/usbserial.c index d6db8565..847746d8 100644 --- a/src/lpc176x/usbserial.c +++ b/src/lpc176x/usbserial.c @@ -8,6 +8,7 @@ #include "LPC17xx.h" // LPC_SC #include "autoconf.h" // CONFIG_SMOOTHIEWARE_BOOTLOADER #include "board/irq.h" // irq_disable +#include "board/misc.h" // timer_read_time #include "byteorder.h" // cpu_to_le32 #include "command.h" // output #include "generic/usb_cdc.h" // usb_notify_ep0 @@ -248,9 +249,14 @@ usb_request_bootloader(void) { if (!CONFIG_SMOOTHIEWARE_BOOTLOADER) return; + // Disable USB and pause for 5ms so host recognizes a disconnect + irq_disable(); + sie_cmd_write(SIE_CMD_SET_DEVICE_STATUS, 0); + uint32_t end = timer_read_time() + timer_from_us(5000); + while (timer_is_before(timer_read_time(), end)) + ; // The "LPC17xx-DFU-Bootloader" will enter the bootloader if the // watchdog timeout flag is set. - irq_disable(); LPC_WDT->WDMOD = 0x07; NVIC_SystemReset(); } |