esp8266: Update port to use new event functions.

This is necessary to avoid watchdog timeout in long i2c.scan(), as
previously machine_i2c.c would call MICROPY_EVENT_POLL_HOOK if
MICROPY_EVENT_POLL_HOOK_FAST was not available.

Compared to previous implementation, this implementation removes the
ets_event_poll() function and calls the SDK function ets_loop_iter() from
MICROPY_INTERNAL_EVENT_HOOK instead.  This allows using the port-agnostic
functions in more places.

There is a small behaviour change, which is that the event loop gets
iterated in a few more places (i.e. anywhere that mp_event_handle_nowait()
is called).  However, this looks like maybe only modselect.c - and is
probably good to process Wi-Fi events in that polling loop.

This work was funded through GitHub Sponsors.

Signed-off-by: Angus Gratton <angus@redyak.com.au>

ports/esp8266/esp_mphal.c

@@ -53,7 +53,7 @@ void mp_hal_init(void) {
 void MP_FASTCODE(mp_hal_delay_us)(uint32_t us) {
     uint32_t start = system_get_time();
     while (system_get_time() - start < us) {
-        ets_event_poll();
+        mp_event_handle_nowait();
     }
 }
 
@@ -122,11 +122,6 @@ uint64_t mp_hal_time_ns(void) {
     return pyb_rtc_get_us_since_epoch() * 1000ULL;
 }
 
-void ets_event_poll(void) {
-    ets_loop_iter();
-    mp_handle_pending(true);
-}
-
 void __assert_func(const char *file, int line, const char *func, const char *expr) {
     printf("assert:%s:%d:%s: %s\n", file, line, func, expr);
     mp_raise_msg(&mp_type_AssertionError, MP_ERROR_TEXT("C-level assert"));

ports/esp8266/esp_mphal.h

@@ -72,9 +72,6 @@ void dupterm_task_init();
 uint32_t esp_disable_irq(void);
 void esp_enable_irq(uint32_t state);
 
-void ets_event_poll(void);
-#define ETS_POLL_WHILE(cond) { while (cond) ets_event_poll(); }
-
 // needed for machine.I2C
 #include "osapi.h"
 #define mp_hal_delay_us_fast(us) os_delay_us(us)

ports/esp8266/machine_uart.c

@@ -300,7 +300,7 @@ STATIC mp_uint_t mp_machine_uart_ioctl(mp_obj_t self_in, mp_uint_t request, uint
             if (mp_machine_uart_txdone(self)) {
                 return 0;
             }
-            MICROPY_EVENT_POLL_HOOK
+            mp_event_wait_ms(1);
         } while (system_get_time() < timeout);
 
         *errcode = MP_ETIMEDOUT;

ports/esp8266/modespnow.c

@@ -285,7 +285,7 @@ static int ringbuf_get_bytes_wait(ringbuf_t *r, uint8_t *data, size_t len, mp_in
     int status = 0;
     while (((status = ringbuf_get_bytes(r, data, len)) == -1)
            && (timeout_ms < 0 || (mp_uint_t)(mp_hal_ticks_ms() - start) < (mp_uint_t)timeout_ms)) {
-        MICROPY_EVENT_POLL_HOOK;
+        mp_event_wait_ms(1);
     }
     return status;
 }

ports/esp8266/modmachine.c

@@ -91,7 +91,7 @@ STATIC mp_obj_t mp_machine_unique_id(void) {
 
 STATIC void mp_machine_idle(void) {
     asm ("waiti 0");
-    ets_event_poll(); // handle any events after possibly a long wait (eg feed WDT)
+    mp_event_handle_nowait(); // handle any events after possibly a long wait (eg feed WDT)
 }
 
 STATIC void mp_machine_lightsleep(size_t n_args, const mp_obj_t *args) {
@@ -106,7 +106,7 @@ STATIC void mp_machine_lightsleep(size_t n_args, const mp_obj_t *args) {
     uint32_t wifi_mode = wifi_get_opmode();
     uint32_t start = system_get_time();
     while (system_get_time() - start <= max_us) {
-        ets_event_poll();
+        mp_event_handle_nowait();
         if (wifi_mode == NULL_MODE) {
             // Can only idle if the wifi is off
             asm ("waiti 0");

ports/esp8266/mpconfigport.h

@@ -7,6 +7,7 @@
 // Board-specific definitions
 #include "mpconfigboard.h"
 
+#include <stdbool.h>
 #include <stdint.h>
 
 // Set the rom feature level.
@@ -116,13 +117,26 @@
 #define MICROPY_FATFS_LFN_CODE_PAGE    437 /* 1=SFN/ANSI 437=LFN/U.S.(OEM) */
 #define MICROPY_ESP8266_APA102         (1)
 
-#define MICROPY_EVENT_POLL_HOOK {ets_event_poll();}
+// No blocking wait-for-event on ESP8266, only non-blocking pump of the "OS" event
+// loop
+//
+// TODO: When TIMEOUT_MS==-1, it may be possible to have MICROPY_INTERNAL_WFE() call the "waiti" instruction.
+// See mp_machine_idle() and mp_machine_lightsleep() in esp8266/modmachine.c
+//
+// Note: We have to scope the declaration of ets_loop_iter() here as there are multiple incompatible
+// definitions at compile time between the SDK and axTLS!
+#define MICROPY_INTERNAL_WFE(TIMEOUT_MS)
+#define MICROPY_INTERNAL_EVENT_HOOK \
+    do { \
+        extern bool ets_loop_iter(void); \
+        ets_loop_iter(); \
+    } while (0)
+
 #define MICROPY_VM_HOOK_COUNT (10)
 #define MICROPY_VM_HOOK_INIT static uint vm_hook_divisor = MICROPY_VM_HOOK_COUNT;
 #define MICROPY_VM_HOOK_POLL if (--vm_hook_divisor == 0) { \
         vm_hook_divisor = MICROPY_VM_HOOK_COUNT; \
-        extern void ets_loop_iter(void); \
-        ets_loop_iter(); \
+        MICROPY_INTERNAL_EVENT_HOOK; \
 }
 #define MICROPY_VM_HOOK_LOOP MICROPY_VM_HOOK_POLL
 #define MICROPY_VM_HOOK_RETURN MICROPY_VM_HOOK_POLL

ports/esp8266/uart.c

@@ -18,6 +18,7 @@
 #include "c_types.h"
 #include "user_interface.h"
 #include "py/mphal.h"
+#include "py/runtime.h"
 
 // seems that this is missing in the Espressif SDK
 #define FUNC_U0RXD 0
@@ -218,7 +219,7 @@ bool ICACHE_FLASH_ATTR uart_rx_wait(uint32_t timeout_us) {
         if (system_get_time() - start >= timeout_us) {
             return false; // timeout
         }
-        ets_event_poll();
+        mp_event_handle_nowait();
     }
 }