qmk_firmware/platforms/chibios/bootloaders/rp2040.c
Stefan Kerkmann 3f5dc47296
[Core] Use polled waiting on ChibiOS platforms that support it (#17607)
* Use polled waiting on platforms that support it

Due to context switching overhead waiting a very short amount of time on
a sleeping thread is often not accurate and in fact not usable for timing
critical usage i.e. in a driver. Thus we use polled waiting for ranges
in the us range on platforms that support it instead. The fallback is
the thread sleeping mechanism.

This includes:

* ARM platforms with CYCCNT register (ARMv7, ARMv8) this is
  incremented at CPU clock frequency
* GD32VF103 RISC-V port with CSR_MCYCLE register this is incremented at
  CPU clock frequency
* RP2040 ARMv6 port which uses the integrated timer peripheral which is
  incremented with a fixed 1MHz frequency

* Use wait_us() instead of chSysPolledDelayX

...as it is powered by busy waiting now.

* Add chibios waiting methods test bench
2022-07-11 15:17:05 +02:00

56 lines
1.9 KiB
C

// Copyright 2022 Stefan Kerkmann
// SPDX-License-Identifier: GPL-2.0-or-later
#include "quantum.h"
#include "hal.h"
#include "bootloader.h"
#include "pico/bootrom.h"
#if !defined(RP2040_BOOTLOADER_DOUBLE_TAP_RESET_LED)
# define RP2040_BOOTLOADER_DOUBLE_TAP_RESET_LED_MASK 0U
#else
# define RP2040_BOOTLOADER_DOUBLE_TAP_RESET_LED_MASK (1U << RP2040_BOOTLOADER_DOUBLE_TAP_RESET_LED)
#endif
__attribute__((weak)) void mcu_reset(void) {
NVIC_SystemReset();
}
void bootloader_jump(void) {
reset_usb_boot(RP2040_BOOTLOADER_DOUBLE_TAP_RESET_LED_MASK, 0U);
}
void enter_bootloader_mode_if_requested(void) {}
#if defined(RP2040_BOOTLOADER_DOUBLE_TAP_RESET)
# if !defined(RP2040_BOOTLOADER_DOUBLE_TAP_RESET_TIMEOUT)
# define RP2040_BOOTLOADER_DOUBLE_TAP_RESET_TIMEOUT 200U
# endif
// Needs to be located in a RAM section that is never initialized on boot to
// preserve its value on reset
static volatile uint32_t __attribute__((section(".ram0.bootloader_magic"))) magic_location;
const uint32_t magic_token = 0xCAFEB0BA;
// We can not use the __early_init / enter_bootloader_mode_if_requested hook as
// we depend on an already initialized system with usable memory regions and
// populated function pointer tables to the optimized math functions in the
// bootrom. This function is called just prior to main.
void __late_init(void) {
// All clocks have to be enabled before jumping to the bootloader function,
// otherwise the bootrom will be stuck infinitely.
clocks_init();
if (magic_location != magic_token) {
magic_location = magic_token;
// ChibiOS is not initialized at this point, so sleeping is only
// possible via busy waiting.
wait_us(RP2040_BOOTLOADER_DOUBLE_TAP_RESET_TIMEOUT * 1000U);
magic_location = 0;
return;
}
magic_location = 0;
reset_usb_boot(RP2040_BOOTLOADER_DOUBLE_TAP_RESET_LED_MASK, 0U);
}
#endif