rp2: Integrate soft_timer using the alarm pool.

The alarm pool is used to schedule the callback to soft_timer_handler().

Signed-off-by: Damien George <damien@micropython.org>

ports/rp2/CMakeLists.txt

@@ -102,6 +102,7 @@ set(MICROPY_SOURCE_LIB
     ${MICROPY_DIR}/shared/runtime/mpirq.c
     ${MICROPY_DIR}/shared/runtime/pyexec.c
     ${MICROPY_DIR}/shared/runtime/stdout_helpers.c
+    ${MICROPY_DIR}/shared/runtime/softtimer.c
     ${MICROPY_DIR}/shared/runtime/sys_stdio_mphal.c
     ${MICROPY_DIR}/shared/timeutils/timeutils.c
     ${MICROPY_DIR}/shared/tinyusb/mp_cdc_common.c

ports/rp2/main.c

@@ -37,6 +37,7 @@
 #include "shared/readline/readline.h"
 #include "shared/runtime/gchelper.h"
 #include "shared/runtime/pyexec.h"
+#include "shared/runtime/softtimer.h"
 #include "tusb.h"
 #include "uart.h"
 #include "modmachine.h"
@@ -212,6 +213,7 @@ int main(int argc, char **argv) {
         #if MICROPY_PY_THREAD
         mp_thread_deinit();
         #endif
+        soft_timer_deinit();
         gc_sweep_all();
         mp_deinit();
     }

ports/rp2/mphalport.c

@@ -29,8 +29,10 @@
 #include "py/mphal.h"
 #include "extmod/misc.h"
 #include "shared/runtime/interrupt_char.h"
+#include "shared/runtime/softtimer.h"
 #include "shared/timeutils/timeutils.h"
 #include "shared/tinyusb/mp_usbd.h"
+#include "pendsv.h"
 #include "tusb.h"
 #include "uart.h"
 #include "hardware/rtc.h"
@@ -44,6 +46,8 @@
 // microseconds since the Epoch.
 STATIC uint64_t time_us_64_offset_from_epoch;
 
+static alarm_id_t soft_timer_alarm_id = 0;
+
 #if MICROPY_HW_ENABLE_UART_REPL || MICROPY_HW_USB_CDC
 
 #ifndef MICROPY_HW_STDIN_BUFFER_LEN
@@ -260,3 +264,22 @@ void mp_hal_get_mac_ascii(int idx, size_t chr_off, size_t chr_len, char *dest) {
 uint32_t storage_read_blocks(uint8_t *dest, uint32_t block_num, uint32_t num_blocks) {
     panic_unsupported();
 }
+
+static int64_t soft_timer_callback(alarm_id_t id, void *user_data) {
+    soft_timer_alarm_id = 0;
+    pendsv_schedule_dispatch(PENDSV_DISPATCH_SOFT_TIMER, soft_timer_handler);
+    return 0; // don't reschedule this alarm
+}
+
+uint32_t soft_timer_get_ms(void) {
+    return mp_hal_ticks_ms();
+}
+
+void soft_timer_schedule_at_ms(uint32_t ticks_ms) {
+    if (soft_timer_alarm_id != 0) {
+        cancel_alarm(soft_timer_alarm_id);
+    }
+    int32_t ms = soft_timer_ticks_diff(ticks_ms, mp_hal_ticks_ms());
+    ms = MAX(0, ms);
+    soft_timer_alarm_id = add_alarm_in_ms(ms, soft_timer_callback, NULL, true);
+}

ports/rp2/mphalport.h

@@ -31,10 +31,14 @@
 #include "hardware/clocks.h"
 #include "hardware/structs/systick.h"
 #include "RP2040.h" // cmsis, for __WFI
+#include "pendsv.h"
 
 #define SYSTICK_MAX (0xffffff)
 #define MICROPY_HW_USB_CDC_TX_TIMEOUT (500)
 
+#define MICROPY_PY_PENDSV_ENTER   pendsv_suspend()
+#define MICROPY_PY_PENDSV_EXIT    pendsv_resume()
+
 extern int mp_interrupt_char;
 extern ringbuf_t stdin_ringbuf;
 

ports/rp2/pendsv.h

@@ -29,6 +29,7 @@
 #include <stddef.h>
 
 enum {
+    PENDSV_DISPATCH_SOFT_TIMER,
     #if MICROPY_PY_LWIP
     PENDSV_DISPATCH_LWIP,
     #endif