DragonProbe/bsp/rp2040/cdc_stdio.c

110 lines
3.0 KiB
C

// vim: set et:
#include <hardware/irq.h>
#include <pico/binary_info.h>
#include <pico/mutex.h>
#include <pico/stdio.h>
#include <pico/stdio/driver.h>
#include <pico/time.h>
#include "pinout.h"
#include "protocfg.h"
#include "tusb.h"
#ifndef PICO_STDIO_USB_STDOUT_TIMEOUT_US
#define PICO_STDIO_USB_STDOUT_TIMEOUT_US 500000
#endif
// *mostly* the same as the SDK code, *except* we have to explicitely pass the
// CDC interface number to the tusb functions, making the SDK code itself very
// non-reusable >__>
static mutex_t stdio_usb_mutex;
static void stdio_usb_out_chars(const char* buf, int length) {
static uint64_t last_avail_time;
uint32_t owner;
if (!mutex_try_enter(&stdio_usb_mutex, &owner)) {
if (owner == get_core_num()) return; // would deadlock otherwise
mutex_enter_blocking(&stdio_usb_mutex);
}
if (tud_cdc_n_connected(CDC_N_STDIO)) {
for (int i = 0; i < length;) {
int n = length - i;
int avail = tud_cdc_n_write_available(CDC_N_STDIO);
if (n > avail) n = avail;
if (n) {
int n2 = tud_cdc_n_write(CDC_N_STDIO, buf + i, n);
tud_task();
tud_cdc_n_write_flush(CDC_N_STDIO);
i += n2;
last_avail_time = time_us_64();
} else {
tud_task();
tud_cdc_n_write_flush(CDC_N_STDIO);
if (!tud_cdc_n_connected(CDC_N_STDIO) ||
(!tud_cdc_n_write_available(CDC_N_STDIO) &&
time_us_64() > last_avail_time + PICO_STDIO_USB_STDOUT_TIMEOUT_US)) {
break;
}
}
}
} else {
// reset our timeout
last_avail_time = 0;
}
mutex_exit(&stdio_usb_mutex);
}
static int stdio_usb_in_chars(char* buf, int length) {
uint32_t owner;
if (!mutex_try_enter(&stdio_usb_mutex, &owner)) {
if (owner == get_core_num()) return PICO_ERROR_NO_DATA; // would deadlock otherwise
mutex_enter_blocking(&stdio_usb_mutex);
}
int rc = PICO_ERROR_NO_DATA;
if (tud_cdc_n_connected(CDC_N_STDIO) && tud_cdc_n_available(CDC_N_STDIO)) {
int count = tud_cdc_n_read(CDC_N_STDIO, buf, length);
rc = count ? count : PICO_ERROR_NO_DATA;
}
mutex_exit(&stdio_usb_mutex);
return rc;
}
extern stdio_driver_t stdio_usb;
// clang-format off
stdio_driver_t stdio_usb = {
.out_chars = stdio_usb_out_chars,
.in_chars = stdio_usb_in_chars,
#if PICO_STDIO_ENABLE_CRLF_SUPPORT
.crlf_enabled = PICO_STDIO_DEFAULT_CRLF
#endif
};
// clang-format on
bool stdio_usb_init(void) {
//#if !PICO_NO_BI_STDIO_USB
bi_decl_if_func_used(bi_program_feature("USB stdin / stdout"));
//#endif
mutex_init(&stdio_usb_mutex);
// unlike with the SDK code, we don't need to add IRQ stuff for the USB
// task, as our main function handles this automatically
stdio_set_driver_enabled(&stdio_usb, true);
return true;
}