watchdogtimer: refactor to new api

This refactors the WatchDogTimer API to use the format proposed in
https://github.com/adafruit/circuitpython/pull/2933#issuecomment-632268227

Signed-off-by: Sean Cross <sean@xobs.io>

5 files changed, 146 insertions, 142 deletions

diff --git a/ports/nrf/common-hal/microcontroller/__init__.c b/ports/nrf/common-hal/microcontroller/__init__.c
index 1dd1cecfb..187b46ad1 100644
--- a/ports/nrf/common-hal/microcontroller/__init__.c
+++ b/ports/nrf/common-hal/microcontroller/__init__.c
@@ -117,12 +117,14 @@ const nvm_bytearray_obj_t common_hal_mcu_nvm_obj = {
 #endif
 
 #if CIRCUITPY_WATCHDOG
-// The singleton nvm.WatchDogTimer object.
-const watchdog_obj_t common_hal_mcu_watchdog_obj = {
+// The singleton watchdog.WatchDogTimer object.
+watchdog_watchdogtimer_obj_t common_hal_mcu_watchdogtimer_obj = {
     .base = {
-        .type = &watchdog_type,
+        .type = &watchdog_watchdogtimer_type,
     },
-    .watchdogtimer = (mp_obj_t)&mp_const_none_obj,
+    .timeout = 0.0f,
+    .sleep = false,
+    .mode = WATCHDOGMODE_NONE,
 };
 #endif
 
diff --git a/ports/nrf/common-hal/watchdog/WatchDogMode.c b/ports/nrf/common-hal/watchdog/WatchDogMode.c
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/ports/nrf/common-hal/watchdog/WatchDogMode.c
diff --git a/ports/nrf/common-hal/watchdog/WatchDogTimer.c b/ports/nrf/common-hal/watchdog/WatchDogTimer.c
index 148146b01..28a96138f 100644
--- a/ports/nrf/common-hal/watchdog/WatchDogTimer.c
+++ b/ports/nrf/common-hal/watchdog/WatchDogTimer.c
@@ -41,8 +41,6 @@
 #include "nrfx_timer.h"
 #include "nrf/timers.h"
 
-STATIC watchdog_watchdogtimer_obj_t *wdt_singleton;
-STATIC mp_obj_t watchdog_watchdogtimer_feed(mp_obj_t self_in);
 STATIC uint8_t timer_refcount = 0;
 #define WATCHDOG_RELOAD_COUNT 2
 STATIC nrfx_timer_t *timer = NULL;
@@ -80,7 +78,7 @@ NORETURN void mp_raise_WatchDogTimeout(void) {
     nlr_raise(MP_OBJ_FROM_PTR(&MP_STATE_VM(mp_watchdog_exception)));
 }
 
-STATIC void watchdogtimer_event_handler(nrf_timer_event_t event_type, void *p_context) {
+STATIC void watchdogtimer_timer_event_handler(nrf_timer_event_t event_type, void *p_context) {
     (void)p_context;
     if (event_type != NRF_TIMER_EVENT_COMPARE0) {
         // Spurious event.
@@ -105,107 +103,20 @@ void watchdog_watchdogtimer_reset(void) {
     timer_refcount = 0;
 }
 
-//| class WDT:
-//|     """Watchdog Timer"""
-//|
-//|     def __init__(self, ):
-//|         """This class represents the system's Watchdog Timer. It is a
-//|         singleton and will always return the same instance.
-//|
-//| """
-//|         ...
-//|
-STATIC mp_obj_t watchdog_watchdogtimer_make_new(const mp_obj_type_t *type, size_t n_args,
-                                 const mp_obj_t *pos_args,
-                                 mp_map_t *kw_args) {
-    enum { ARG_timeout, ARG_sleep, ARG_hardware };
-    static const mp_arg_t allowed_args[] = {
-        {MP_QSTR_timeout, MP_ARG_OBJ | MP_ARG_REQUIRED},
-        {MP_QSTR_sleep, MP_ARG_BOOL, {.u_bool = false}},
-        {MP_QSTR_hardware, MP_ARG_BOOL, {.u_bool = false}},
-    };
-    mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
-    mp_obj_exception_clear_traceback(MP_OBJ_FROM_PTR(&MP_STATE_VM(mp_watchdog_exception)));
-
-    mp_arg_parse_all(n_args, pos_args, kw_args, MP_ARRAY_SIZE(allowed_args),
-                     allowed_args, args);
-    mp_float_t timeout = mp_obj_get_float(args[ARG_timeout].u_obj);
-    bool hardware = args[ARG_hardware].u_bool;
-    bool sleep = args[ARG_sleep].u_bool;
-
-    // If the hardware timer is already running, return that timer.
-    // If the parameters have changed, then ignore them, but print
-    // an error.
-    if (wdt_singleton && hardware) {
-        if ((sleep != wdt_singleton->sleep)
-         || (hardware != wdt_singleton->hardware)
-         || fabsf(timeout - wdt_singleton->timeout) > 0.01f) {
-            // Print a warning indicating things aren't quite right
-            // mp_printf(&mp_stderr_print, translate("warning: hardware timer was already running"));
-        }
-        watchdogtimer_hardware_feed();
-        return wdt_singleton;
-    }
-
-    if (timeout <= 0) {
-        mp_raise_ValueError(translate("watchdog timeout must be greater than 0"));
-    }
-
-    watchdog_watchdogtimer_obj_t *self = m_new_obj(watchdog_watchdogtimer_obj_t);
-    self->base.type = &watchdog_watchdogtimer_type;
-    self->timeout = timeout;
-    self->sleep = sleep;
-    self->hardware = hardware;
-
-    if (hardware) {
-        watchdogtimer_hardware_init(self->timeout, self->sleep);
-        wdt_singleton = self;
-    } else {
-        uint64_t ticks = timeout * 31250ULL;
-        if (ticks > UINT32_MAX) {
-            mp_raise_ValueError(translate("timeout duration exceeded the maximum supported value"));
-        }
-
-        if (timer_refcount == 0) {
-            timer = nrf_peripherals_allocate_timer_or_throw();
-        }
-        timer_refcount++;
-
-        nrfx_timer_config_t timer_config = {
-            .frequency = NRF_TIMER_FREQ_31250Hz,
-            .mode = NRF_TIMER_MODE_TIMER,
-            .bit_width = NRF_TIMER_BIT_WIDTH_32,
-            .interrupt_priority = NRFX_TIMER_DEFAULT_CONFIG_IRQ_PRIORITY,
-            .p_context = self,
-        };
-
-        nrfx_timer_init(timer, &timer_config, &watchdogtimer_event_handler);
-
-        // true enables interrupt.
-        nrfx_timer_clear(timer);
-        nrfx_timer_compare(timer, NRF_TIMER_CC_CHANNEL0, ticks, true);
-        nrfx_timer_resume(timer);
-    }
-
-    // Feed the watchdog, in case there's a timer that's already running
-    // and it's only partially finished.
-    mp_obj_t *self_obj = MP_OBJ_FROM_PTR(self);
-    watchdog_watchdogtimer_feed(self_obj);
-    return self_obj;
-}
-
 //|     def feed(self):
 //|         """Feed the watchdog timer. This must be called regularly, otherwise
-//|         the system will reset."""
+//|         the timer will expire."""
 //|         ...
 //|
 STATIC mp_obj_t watchdog_watchdogtimer_feed(mp_obj_t self_in) {
     watchdog_watchdogtimer_obj_t *self = MP_OBJ_TO_PTR(self_in);
 
-    if (self->hardware) {
+    if (self->mode == WATCHDOGMODE_RESET) {
         watchdogtimer_hardware_feed();
-    } else {
+    } else if (self->mode == WATCHDOGMODE_RAISE) {
         nrfx_timer_clear(timer);
+    } else if (self->mode == WATCHDOGMODE_NONE) {
+        mp_raise_ValueError(translate("WatchDogTimer is not currently running"));
     }
     return mp_const_none;
 }
@@ -219,71 +130,178 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_1(watchdog_watchdogtimer_feed_obj, watchdog_watch
 STATIC mp_obj_t watchdog_watchdogtimer_deinit(mp_obj_t self_in) {
     watchdog_watchdogtimer_obj_t *self = MP_OBJ_TO_PTR(self_in);
 
-    if (!self->hardware) {
+    if (self->mode == WATCHDOGMODE_RAISE) {
         timer_refcount--;
         if (timer_refcount == 0) {
             nrf_peripherals_free_timer(timer);
             timer = NULL;
         }
+    } else if (self->mode == WATCHDOGMODE_RESET) {
+        mp_raise_NotImplementedError(translate("WatchDogTimer cannot be deinitialized once mode is set to RESET"));
     }
 
     return mp_const_none;
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_1(watchdog_watchdogtimer_deinit_obj, watchdog_watchdogtimer_deinit);
 
-//|     timeout: int = ...
-//|     """The maximum number of milliseconds that can elapse between calls
+//|     timeout: float = ...
+//|     """The maximum number of seconds that can elapse between calls
 //|     to feed()"""
 //|
-STATIC mp_obj_t watchdog_watchdogtimer_get_timeout(mp_obj_t self_in) {
+STATIC mp_obj_t watchdog_watchdogtimer_obj_get_timeout(mp_obj_t self_in) {
     watchdog_watchdogtimer_obj_t *self = MP_OBJ_TO_PTR(self_in);
     return mp_obj_new_float(self->timeout);
 }
-MP_DEFINE_CONST_FUN_OBJ_1(watchdog_watchdogtimer_get_timeout_obj, watchdog_watchdogtimer_get_timeout);
+MP_DEFINE_CONST_FUN_OBJ_1(watchdog_watchdogtimer_get_timeout_obj, watchdog_watchdogtimer_obj_get_timeout);
+
+STATIC mp_obj_t watchdog_watchdogtimer_obj_set_timeout(mp_obj_t self_in, mp_obj_t timeout_obj) {
+    watchdog_watchdogtimer_obj_t *self = MP_OBJ_TO_PTR(self_in);
+    mp_float_t timeout = mp_obj_get_float(timeout_obj);
+
+    if (timeout <= 0) {
+        mp_raise_ValueError(translate("watchdog timeout must be greater than 0"));
+    }
+
+    if (self->mode == WATCHDOGMODE_RESET) {
+        // If the WatchDogTimer is already running in "RESET" mode, raise an error
+        // since the mode cannot be changed once started.
+        mp_raise_TypeError(translate("Cannot change the timeout once mode is WatchDogMode.RESET"));
+    } else if (self->mode == WATCHDOGMODE_RAISE) {
+        // If the WatchDogTimer is already running in "RAISE" mode, reset the timer
+        // with the new value.
+        uint64_t ticks = timeout * 31250ULL;
+        if (ticks > UINT32_MAX) {
+            mp_raise_ValueError(translate("timeout duration exceeded the maximum supported value"));
+        }
+        nrfx_timer_clear(timer);
+        nrfx_timer_compare(timer, NRF_TIMER_CC_CHANNEL0, ticks, true);
+    }
+
+    self->timeout = timeout;
+    return mp_const_none;
+}
+MP_DEFINE_CONST_FUN_OBJ_2(watchdog_watchdogtimer_set_timeout_obj, watchdog_watchdogtimer_obj_set_timeout);
 
 const mp_obj_property_t watchdog_watchdogtimer_timeout_obj = {
     .base.type = &mp_type_property,
     .proxy = {(mp_obj_t)&watchdog_watchdogtimer_get_timeout_obj,
-              (mp_obj_t)&mp_const_none_obj,
+              (mp_obj_t)&watchdog_watchdogtimer_set_timeout_obj,
               (mp_obj_t)&mp_const_none_obj},
 };
 
-mp_obj_t watchdog_watchdogtimer___enter__(mp_obj_t self_in) {
+//|     mode: watchdog.WatchDogMode = ...
+//|     """The current operating mode of the WatchDogTimer `watchdog.WatchDogMode`.
+//|
+//|     Setting a WatchDogMode activates the WatchDog::
+//|
+//|       import microcontroller
+//|       import watchdog
+//|
+//|       w = microcontroller.watchdog
+//|       w.timeout = 5
+//|       w.mode = watchdog.WatchDogMode.RAISE
+//|
+//|
+//|     Once set, the WatchDogTimer will perform the specified action if the timer expires.
+//|
+STATIC mp_obj_t watchdog_watchdogtimer_obj_get_mode(mp_obj_t self_in) {
     watchdog_watchdogtimer_obj_t *self = MP_OBJ_TO_PTR(self_in);
-
-    if (!self->hardware) {
-        nrfx_timer_resume(timer);
+    switch (self->mode) {
+        case WATCHDOGMODE_NONE: default: return (mp_obj_t)MP_ROM_PTR(&watchdog_watchdogmode_none_obj);
+        case WATCHDOGMODE_RAISE: return (mp_obj_t)MP_ROM_PTR(&watchdog_watchdogmode_raise_obj);
+        case WATCHDOGMODE_RESET: return (mp_obj_t)MP_ROM_PTR(&watchdog_watchdogmode_reset_obj);
     }
-    watchdog_watchdogtimer_feed(self_in);
-    return self_in;
 }
-MP_DEFINE_CONST_FUN_OBJ_1(watchdog_watchdogtimer___enter___obj, watchdog_watchdogtimer___enter__);
-
-STATIC mp_obj_t watchdog_watchdogtimer___exit__(size_t n_args, const mp_obj_t *args) {
-    (void)n_args;
-    watchdog_watchdogtimer_obj_t *self = MP_OBJ_TO_PTR(args[0]);
-    if (!self->hardware) {
-        if (timer) {
-            nrfx_timer_pause(timer);
+MP_DEFINE_CONST_FUN_OBJ_1(watchdog_watchdogtimer_get_mode_obj, watchdog_watchdogtimer_obj_get_mode);
+
+STATIC mp_obj_t watchdog_watchdogtimer_obj_set_mode(mp_obj_t self_in, mp_obj_t mode_obj) {
+    watchdog_watchdogtimer_obj_t *self = MP_OBJ_TO_PTR(self_in);
+    watchdog_watchdogmode_obj_t *mode = MP_OBJ_TO_PTR(mode_obj);
+    if (mode == MP_ROM_PTR(&watchdog_watchdogmode_none_obj)) {
+        if (self->mode == WATCHDOGMODE_RESET) {
+            mp_raise_TypeError(translate("WatchDogTimer mode cannot be changed once set to WatchDogMode.RESET"));
+        }
+        else if (self->mode == WATCHDOGMODE_RAISE) {
+            timer_refcount--;
+            if (timer_refcount == 0) {
+                nrf_peripherals_free_timer(timer);
+                timer = NULL;
+            }
+        }
+        self->mode = WATCHDOGMODE_NONE;
+
+    } else if (mode == MP_ROM_PTR(&watchdog_watchdogmode_raise_obj)) {
+        if (self->timeout <= 0) {
+            mp_raise_ValueError(translate("watchdog timeout must be greater than 0"));
+        }
+        if (self->mode == WATCHDOGMODE_RESET) {
+            mp_raise_ValueError(translate("WatchDogTimer mode cannot be changed once set to WatchDogMode.RESET"));
+        }
+        else if (self->mode == WATCHDOGMODE_NONE) {
+            uint64_t ticks = self->timeout * 31250ULL;
+            if (ticks > UINT32_MAX) {
+                mp_raise_ValueError(translate("timeout duration exceeded the maximum supported value"));
+            }
+
+            if (timer_refcount == 0) {
+                timer = nrf_peripherals_allocate_timer_or_throw();
+            }
+            timer_refcount++;
+
+            nrfx_timer_config_t timer_config = {
+                .frequency = NRF_TIMER_FREQ_31250Hz,
+                .mode = NRF_TIMER_MODE_TIMER,
+                .bit_width = NRF_TIMER_BIT_WIDTH_32,
+                .interrupt_priority = NRFX_TIMER_DEFAULT_CONFIG_IRQ_PRIORITY,
+                .p_context = self,
+            };
+
+            nrfx_timer_init(timer, &timer_config, &watchdogtimer_timer_event_handler);
+
+            // true enables interrupt.
+            nrfx_timer_clear(timer);
+            nrfx_timer_compare(timer, NRF_TIMER_CC_CHANNEL0, ticks, true);
+            nrfx_timer_resume(timer);
         }
+        self->mode = WATCHDOGMODE_RAISE;
+
+    } else if (mode == MP_ROM_PTR(&watchdog_watchdogmode_reset_obj)) {
+        if (self->timeout <= 0) {
+            mp_raise_ValueError(translate("watchdog timeout must be greater than 0"));
+        }
+        if (self->mode == WATCHDOGMODE_RAISE) {
+            timer_refcount--;
+            if (timer_refcount == 0) {
+                nrf_peripherals_free_timer(timer);
+                timer = NULL;
+            }
+        }
+        watchdogtimer_hardware_init(self->timeout, self->sleep);
+        self->mode = WATCHDOGMODE_RESET;
     }
+
     return mp_const_none;
 }
-STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(watchdog_watchdogtimer___exit___obj, 4, 4, watchdog_watchdogtimer___exit__);
+MP_DEFINE_CONST_FUN_OBJ_2(watchdog_watchdogtimer_set_mode_obj, watchdog_watchdogtimer_obj_set_mode);
+
+const mp_obj_property_t watchdog_watchdogtimer_mode_obj = {
+    .base.type = &mp_type_property,
+    .proxy = {(mp_obj_t)&watchdog_watchdogtimer_get_mode_obj,
+              (mp_obj_t)&watchdog_watchdogtimer_set_mode_obj,
+              (mp_obj_t)&mp_const_none_obj},
+};
 
 STATIC const mp_rom_map_elem_t watchdog_watchdogtimer_locals_dict_table[] = {
     { MP_ROM_QSTR(MP_QSTR_feed), MP_ROM_PTR(&watchdog_watchdogtimer_feed_obj) },
     { MP_ROM_QSTR(MP_QSTR_deinit), MP_ROM_PTR(&watchdog_watchdogtimer_deinit_obj) },
     { MP_ROM_QSTR(MP_QSTR_timeout), MP_ROM_PTR(&watchdog_watchdogtimer_timeout_obj) },
-    // { MP_ROM_QSTR(MP_QSTR___del__), MP_ROM_PTR(&mp_stream_close_obj) },
-    { MP_ROM_QSTR(MP_QSTR___enter__), MP_ROM_PTR(&watchdog_watchdogtimer___enter___obj) },
-    { MP_ROM_QSTR(MP_QSTR___exit__), MP_ROM_PTR(&watchdog_watchdogtimer___exit___obj) },
+    { MP_ROM_QSTR(MP_QSTR_mode), MP_ROM_PTR(&watchdog_watchdogtimer_mode_obj) },
 };
 STATIC MP_DEFINE_CONST_DICT(watchdog_watchdogtimer_locals_dict, watchdog_watchdogtimer_locals_dict_table);
 
 const mp_obj_type_t watchdog_watchdogtimer_type = {
     { &mp_type_type },
     .name = MP_QSTR_WatchDogTimer,
-    .make_new = watchdog_watchdogtimer_make_new,
+    // .make_new = watchdog_watchdogtimer_make_new,
     .locals_dict = (mp_obj_dict_t*)&watchdog_watchdogtimer_locals_dict,
 };
diff --git a/ports/nrf/common-hal/watchdog/WatchDogTimer.h b/ports/nrf/common-hal/watchdog/WatchDogTimer.h
index c59796820..417694469 100644
--- a/ports/nrf/common-hal/watchdog/WatchDogTimer.h
+++ b/ports/nrf/common-hal/watchdog/WatchDogTimer.h
@@ -29,12 +29,13 @@
 
 #include "py/obj.h"
 #include "shared-bindings/watchdog/WatchDogTimer.h"
+#include "shared-bindings/watchdog/WatchDogMode.h"
 
 typedef struct _watchdog_watchdogtimer_obj_t {
     mp_obj_base_t base;
     mp_float_t timeout;
     bool sleep;
-    bool hardware;
+    watchdog_watchdogmode_t mode;
 } watchdog_watchdogtimer_obj_t;
 
 #endif  // MICROPY_INCLUDED_NRF_COMMON_HAL_WATCHDOG_WATCHDOGTIMER_H
diff --git a/ports/nrf/common-hal/watchdog/__init__.c b/ports/nrf/common-hal/watchdog/__init__.c
index 4013d1317..79875d127 100644
--- a/ports/nrf/common-hal/watchdog/__init__.c
+++ b/ports/nrf/common-hal/watchdog/__init__.c
@@ -23,20 +23,3 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
-#include "py/obj.h"
-#include "common-hal/watchdog/__init__.h"
-#include "common-hal/watchdog/WatchDogTimer.h"
-
-STATIC const mp_rom_map_elem_t watchdog_locals_dict_table[] = {
-    {MP_ROM_QSTR(MP_QSTR_WatchDogTimer), MP_ROM_PTR(&watchdog_watchdogtimer_type) },
-};
-STATIC MP_DEFINE_CONST_DICT(watchdog_locals_dict, watchdog_locals_dict_table);
-
-const mp_obj_type_t watchdog_type = {
-    { &mp_type_type },
-    .name = MP_QSTR_watchdog,
-    // .make_new = watchdog_watchdogtimer_make_new,
-    .locals_dict = (mp_obj_dict_t*)&watchdog_locals_dict,
-};
-