handle tinyusb device tasks on a timer, allows delays in app

This commit is contained in:
Joey Castillo 2021-08-28 19:49:49 -04:00
parent 27e3863a05
commit ef0ed276a5
2 changed files with 38 additions and 8 deletions

View File

@ -58,11 +58,8 @@ int main(void) {
// check if we are plugged into USB power. // check if we are plugged into USB power.
watch_enable_digital_input(VBUS_DET); watch_enable_digital_input(VBUS_DET);
watch_enable_pull_down(VBUS_DET); watch_enable_pull_down(VBUS_DET);
// IF WE ARE:
if (watch_get_pin_level(VBUS_DET)) { if (watch_get_pin_level(VBUS_DET)) {
// Ramp up to 16 MHz (seems necessary for USB to work)... // if so, enable USB functionality.
hri_oscctrl_write_OSC16MCTRL_reg(OSCCTRL, OSCCTRL_OSC16MCTRL_ONDEMAND | OSCCTRL_OSC16MCTRL_FSEL_16 | OSCCTRL_OSC16MCTRL_ENABLE);
// ...and enable USB functionality.
_watch_enable_usb(); _watch_enable_usb();
} }
watch_disable_digital_input(VBUS_DET); watch_disable_digital_input(VBUS_DET);
@ -71,11 +68,10 @@ int main(void) {
app_setup(); app_setup();
while (1) { while (1) {
bool usb_enabled = hri_usbdevice_get_CTRLA_ENABLE_bit(USB);
bool can_sleep = app_loop(); bool can_sleep = app_loop();
if (hri_usbdevice_get_CTRLA_ENABLE_bit(USB)) {
// if USB is enabled, do not sleep, and handle any pending TinyUSB tasks. if (can_sleep && !usb_enabled) {
tud_task();
} else if (can_sleep) {
app_prepare_for_sleep(); app_prepare_for_sleep();
sleep(4); sleep(4);
app_wake_from_sleep(); app_wake_from_sleep();

View File

@ -49,6 +49,11 @@ void _watch_enable_usb() {
// disable USB, just in case. // disable USB, just in case.
hri_usb_clear_CTRLA_ENABLE_bit(USB); hri_usb_clear_CTRLA_ENABLE_bit(USB);
// Ramp up to 16 MHz (seems necessary for USB to work)...
hri_oscctrl_write_OSC16MCTRL_reg(OSCCTRL, OSCCTRL_OSC16MCTRL_ONDEMAND | OSCCTRL_OSC16MCTRL_FSEL_16 | OSCCTRL_OSC16MCTRL_ENABLE);
// ...and wait for it to be ready.
while (!hri_oscctrl_get_STATUS_OSC16MRDY_bit(OSCCTRL));
// reset flags and disable DFLL // reset flags and disable DFLL
OSCCTRL->INTFLAG.reg = OSCCTRL_INTFLAG_DFLLRDY; OSCCTRL->INTFLAG.reg = OSCCTRL_INTFLAG_DFLLRDY;
OSCCTRL->DFLLCTRL.reg = 0; OSCCTRL->DFLLCTRL.reg = 0;
@ -86,7 +91,31 @@ void _watch_enable_usb() {
gpio_set_pin_function(PIN_PA24, PINMUX_PA24G_USB_DM); gpio_set_pin_function(PIN_PA24, PINMUX_PA24G_USB_DM);
gpio_set_pin_function(PIN_PA25, PINMUX_PA25G_USB_DP); gpio_set_pin_function(PIN_PA25, PINMUX_PA25G_USB_DP);
// before we init TinyUSB, we are going to need a periodic callback to handle TinyUSB tasks.
// TC2 and TC3 are reserved for devices on the 9-pin connector, so let's use TC0.
// clock TC0 with the 16 MHz clock on GCLK0.
hri_gclk_write_PCHCTRL_reg(GCLK, TC0_GCLK_ID, GCLK_PCHCTRL_GEN_GCLK0_Val | GCLK_PCHCTRL_CHEN);
// and enable the peripheral clock.
hri_mclk_set_APBCMASK_TC0_bit(MCLK);
// disable and reset TC0.
hri_tc_clear_CTRLA_ENABLE_bit(TC0);
hri_tc_wait_for_sync(TC0, TC_SYNCBUSY_ENABLE);
hri_tc_write_CTRLA_reg(TC0, TC_CTRLA_SWRST);
hri_tc_wait_for_sync(TC0, TC_SYNCBUSY_SWRST);
// configure the TC to overflow 1,000 times per second
hri_tc_write_CTRLA_reg(TC0, TC_CTRLA_PRESCALER_DIV64 | // divide the clock by 64 to count at 250000 KHz
TC_CTRLA_MODE_COUNT8 | // count in 8-bit mode
TC_CTRLA_RUNSTDBY); // run in standby, just in case we figure that out
hri_tccount8_write_PER_reg(TC0, 250); // 250000 KHz / 250 = 1,000 Hz
// set an interrupt on overflow; this will call TC0_Handler below.
hri_tc_set_INTEN_OVF_bit(TC0);
NVIC_ClearPendingIRQ(TC0_IRQn);
NVIC_EnableIRQ (TC0_IRQn);
// now we can init TinyUSB
tusb_init(); tusb_init();
// and start the timer that handles USB device tasks.
hri_tc_set_CTRLA_ENABLE_bit(TC0);
} }
// this function ends up getting called by printf to log stuff to the USB console. // this function ends up getting called by printf to log stuff to the USB console.
@ -119,6 +148,11 @@ void USB_Handler(void) {
tud_int_handler(0); tud_int_handler(0);
} }
void TC0_Handler(void) {
tud_task();
TC0->COUNT8.INTFLAG.reg |= TC_INTFLAG_OVF;
}
// USB Descriptors and tinyUSB callbacks follow. // USB Descriptors and tinyUSB callbacks follow.