add alternate _write for debugging USB issues

This commit is contained in:
Joey Castillo 2021-08-28 19:36:00 -04:00
parent 048b5c1d3f
commit 27e3863a05
3 changed files with 30 additions and 4 deletions

View File

@ -43,8 +43,8 @@
#define CFG_TUSB_OS OPT_OS_NONE #define CFG_TUSB_OS OPT_OS_NONE
// Do not use TinyUSB debug, as our printf method prints stuff to the USB console. // disable TinyUSB debug. our printf method prints stuff to the USB console, so you just get infinite noise.
// if you must, modify _write in watch_private.c to use an alternate destination like a UART. // if you need to debug tinyUSB issues, use the alternate _write function in watch_private.c to echo to the UART.
#define CFG_TUSB_DEBUG 0 #define CFG_TUSB_DEBUG 0
/* USB DMA on some MCUs can only access a specific SRAM region with restriction on alignment. /* USB DMA on some MCUs can only access a specific SRAM region with restriction on alignment.

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@ -106,6 +106,15 @@ int _read() {
return 0; return 0;
} }
// Alternate function that outputs to the debug UART. useful for debugging USB issues.
// int _write(int file, char *ptr, int len) {
// (void)file;
// int pos = 0;
// while(pos < len) watch_debug_putc(ptr[pos++]);
// return 0;
// }
void USB_Handler(void) { void USB_Handler(void) {
tud_int_handler(0); tud_int_handler(0);
} }

View File

@ -53,8 +53,25 @@
#include "peripheral_clk_config.h" #include "peripheral_clk_config.h"
void watch_enable_debug_uart(uint32_t baud) { void watch_enable_debug_uart(uint32_t baud) {
/// FIXME: UART baud rate calculation will be incorrect if plugged into USB / running at 16 MHz uint8_t fsel = hri_oscctrl_get_OSC16MCTRL_FSEL_bf(OSCCTRL, OSCCTRL_OSC16MCTRL_MASK);
uint64_t br = (uint64_t)65536 * (CONF_CPU_FREQUENCY - 16 * baud) / CONF_CPU_FREQUENCY; uint32_t freq = 0;
switch (fsel) {
case OSCCTRL_OSC16MCTRL_FSEL_4_Val:
freq = 4000000;
break;
case OSCCTRL_OSC16MCTRL_FSEL_8_Val:
freq = 8000000;
break;
case OSCCTRL_OSC16MCTRL_FSEL_12_Val:
freq = 12000000;
break;
case OSCCTRL_OSC16MCTRL_FSEL_16_Val:
freq = 16000000;
break;
default:
return;
}
uint64_t br = (uint64_t)65536 * ((freq * 4) - 16 * baud) / (freq * 4);
gpio_set_pin_direction(D1, GPIO_DIRECTION_IN); gpio_set_pin_direction(D1, GPIO_DIRECTION_IN);
gpio_set_pin_function(D1, PINMUX_PB00C_SERCOM3_PAD2); gpio_set_pin_function(D1, PINMUX_PB00C_SERCOM3_PAD2);