nrf: Use common implementation of machine disable/enable IRQ.

This is a breaking change due to the signature change of `enable_irq()`.
Previously the signature was:

    machine.enable_irq()

Now the signature matches other ports, and the docs, and is:

    machine.enable_irq(state)

Where `state` is the return value from `machine.disable_irq()`.

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

ports/nrf/modules/machine/modmachine.c

@@ -85,8 +85,6 @@
 
 #define MICROPY_PY_MACHINE_EXTRA_GLOBALS \
     { MP_ROM_QSTR(MP_QSTR_info),               MP_ROM_PTR(&machine_info_obj) }, \
-    { MP_ROM_QSTR(MP_QSTR_enable_irq),         MP_ROM_PTR(&machine_enable_irq_obj) }, \
-    { MP_ROM_QSTR(MP_QSTR_disable_irq),        MP_ROM_PTR(&machine_disable_irq_obj) }, \
     { MP_ROM_QSTR(MP_QSTR_sleep),              MP_ROM_PTR(&machine_lightsleep_obj) }, \
     { MP_ROM_QSTR(MP_QSTR_Pin),                MP_ROM_PTR(&pin_type) }, \
     \
@@ -214,24 +212,3 @@ static mp_obj_t mp_machine_get_freq(void) {
 static void mp_machine_set_freq(size_t n_args, const mp_obj_t *args) {
     mp_raise_NotImplementedError(NULL);
 }
-
-static mp_obj_t machine_enable_irq(void) {
-    #ifndef BLUETOOTH_SD
-    __enable_irq();
-    #else
-
-    #endif
-    return mp_const_none;
-}
-MP_DEFINE_CONST_FUN_OBJ_0(machine_enable_irq_obj, machine_enable_irq);
-
-// Resets the board in a manner similar to pushing the external RESET button.
-static mp_obj_t machine_disable_irq(void) {
-    #ifndef BLUETOOTH_SD
-    __disable_irq();
-    #else
-
-    #endif
-    return mp_const_none;
-}
-MP_DEFINE_CONST_FUN_OBJ_0(machine_disable_irq_obj, machine_disable_irq);

ports/nrf/mpconfigport.h

@@ -181,6 +181,7 @@
 #define MICROPY_PY_MACHINE_RESET    (1)
 #define MICROPY_PY_MACHINE_BARE_METAL_FUNCS (1)
 #define MICROPY_PY_MACHINE_BOOTLOADER (1)
+#define MICROPY_PY_MACHINE_DISABLE_IRQ_ENABLE_IRQ (1)
 #define MICROPY_PY_MACHINE_PULSE    (0)
 #define MICROPY_PY_MACHINE_SOFTI2C  (MICROPY_PY_MACHINE_I2C)
 

ports/nrf/mphalport.h

@@ -35,6 +35,22 @@
 #include "nrfx_config.h"
 #include "shared/runtime/interrupt_char.h"
 
+// Entering a critical section.
+#ifndef BLUETOOTH_SD
+#define MICROPY_BEGIN_ATOMIC_SECTION()     disable_irq()
+#define MICROPY_END_ATOMIC_SECTION(state)  enable_irq(state)
+#endif
+
+static inline void enable_irq(mp_uint_t state) {
+    __set_PRIMASK(state);
+}
+
+static inline mp_uint_t disable_irq(void) {
+    mp_uint_t state = __get_PRIMASK();
+    __disable_irq();
+    return state;
+}
+
 typedef enum
 {
     HAL_OK       = 0x00,