hosted/platform: Ensure we maintain the reset condition for detach fo…

…r at least 10ms

src/platforms/native/platform.c

@@ -39,6 +39,7 @@
 #include <libopencm3/stm32/spi.h>
 #include <libopencm3/stm32/flash.h>
 #include <libopencm3/stm32/timer.h>
+#include <libopencm3/cm3/systick.h>
 
 static void adc_init(void);
 static void setup_vbus_irq(void);
@@ -415,6 +416,13 @@ void platform_request_boot(void)
  gpio_set_mode(USB_PU_PORT, GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, USB_PU_PIN);
  gpio_set_mode(USB_PORT, GPIO_MODE_INPUT, GPIO_CNF_INPUT_PULL_UPDOWN, USB_DP_PIN | USB_DM_PIN);
  gpio_clear(USB_PORT, USB_DP_PIN | USB_DM_PIN);
+ /* Make sure we drive the USB reset condition for at least 10ms */
+ while (!(STK_CSR & STK_CSR_COUNTFLAG))
+ continue;
+ for (size_t count = 0U; count < 10U * SYSTICKMS; ++count) {
+ while (!(STK_CSR & STK_CSR_COUNTFLAG))
+ continue;
+ }
 
  /* Drive boot request pin */
  gpio_set_mode(GPIOB, GPIO_MODE_OUTPUT_2_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, GPIO12);