zephyr/machine_timer: Add machine.Timer class implementation.

Simple `machine.Timer` implementation in-line with the rest of the
MicroPython ports.

Note: Only virtual timers are supported (not linked to any particular
hardware peripheral).

Tested with the nRF5340 and the nRF52840.

Signed-off-by: danicampora <danicampora@gmail.com>

3 files changed, 203 insertions, 0 deletions

diff --git a/ports/zephyr/CMakeLists.txt b/ports/zephyr/CMakeLists.txt
index 68b6c0700..b95508906 100644
--- a/ports/zephyr/CMakeLists.txt
+++ b/ports/zephyr/CMakeLists.txt
@@ -40,6 +40,7 @@ set(MICROPY_SOURCE_PORT
     machine_i2c.c
     machine_spi.c
     machine_pin.c
+    machine_timer.c
     modbluetooth_zephyr.c
     modsocket.c
     modzephyr.c
diff --git a/ports/zephyr/machine_timer.c b/ports/zephyr/machine_timer.c
new file mode 100644
index 000000000..8ab2f6291
--- /dev/null
+++ b/ports/zephyr/machine_timer.c
@@ -0,0 +1,201 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2025 Daniel Campora on behalf of REMOTE TECH LTD
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include <stdint.h>
+#include <stdio.h>
+
+#include "py/mperrno.h"
+#include "py/obj.h"
+#include "py/runtime.h"
+#include "modmachine.h"
+#include <zephyr/kernel.h>
+#include <zephyr/device.h>
+#include <zephyr/sys/printk.h>
+
+#define TIMER_MS_PER_TICK (1000)
+
+typedef enum _machine_timer_mode_t {
+    TIMER_MODE_ONE_SHOT = 0,
+    TIMER_MODE_PERIODIC
+} machine_timer_mode_t;
+
+typedef struct _machine_timer_obj_t {
+    mp_obj_base_t base;
+
+    struct k_timer my_timer;
+
+    machine_timer_mode_t mode;
+    uint32_t period_ms;
+
+    mp_obj_t callback;
+
+    struct _machine_timer_obj_t *next;
+} machine_timer_obj_t;
+
+const mp_obj_type_t machine_timer_type;
+
+static mp_obj_t machine_timer_init_helper(machine_timer_obj_t *self, mp_uint_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args);
+static mp_obj_t machine_timer_deinit(mp_obj_t self_in);
+
+static void machine_timer_callback(struct k_timer *timer) {
+    machine_timer_obj_t *self = (machine_timer_obj_t *)k_timer_user_data_get(timer);
+    if (self->mode == TIMER_MODE_ONE_SHOT) {
+        machine_timer_deinit(self);
+    }
+    if (self->callback != mp_const_none) {
+        mp_sched_schedule(self->callback, MP_OBJ_FROM_PTR(self));
+    }
+}
+
+static void machine_timer_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
+    machine_timer_obj_t *self = self_in;
+    qstr mode_str = (self->mode == TIMER_MODE_PERIODIC) ? MP_QSTR_PERIODIC : MP_QSTR_ONE_SHOT;
+    mp_printf(print, "Timer(-1, mode=%q, period=%lu)", mode_str, self->period_ms);
+}
+
+static mp_obj_t machine_timer_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *args) {
+    mp_arg_check_num(n_args, n_kw, 1, MP_OBJ_FUN_ARGS_MAX, true);
+
+    if (mp_obj_get_int(args[0]) != -1) {
+        mp_raise_ValueError(MP_ERROR_TEXT("only virtual timers are supported"));
+    }
+
+    // Create the new timer.
+    machine_timer_obj_t *self = mp_obj_malloc_with_finaliser(machine_timer_obj_t, &machine_timer_type);
+
+    // Add the timer to the linked-list of timers
+    self->next = MP_STATE_PORT(machine_timer_obj_head);
+    MP_STATE_PORT(machine_timer_obj_head) = self;
+
+    if (n_args > 1 || n_kw > 0) {
+        mp_map_t kw_args;
+        mp_map_init_fixed_table(&kw_args, n_kw, args + n_args);
+        machine_timer_init_helper(self, n_args - 1, args + 1, &kw_args);
+    }
+    return self;
+}
+
+static mp_obj_t machine_timer_init_helper(machine_timer_obj_t *self, mp_uint_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
+    enum {
+        ARG_mode,
+        ARG_callback,
+        ARG_period,
+        ARG_freq,
+    };
+    static const mp_arg_t allowed_args[] = {
+        { MP_QSTR_mode,         MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = TIMER_MODE_PERIODIC} },
+        { MP_QSTR_callback,     MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = mp_const_none} },
+        { MP_QSTR_period,       MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0xffffffff} },
+        #if MICROPY_PY_BUILTINS_FLOAT
+        { MP_QSTR_freq,         MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = mp_const_none} },
+        #else
+        { MP_QSTR_freq,         MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0xffffffff} },
+        #endif
+    };
+
+    mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
+    mp_arg_parse_all(n_args, pos_args, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
+
+    #if MICROPY_PY_BUILTINS_FLOAT
+    if (args[ARG_freq].u_obj != mp_const_none) {
+        self->period_ms = (uint32_t)(TIMER_MS_PER_TICK / mp_obj_get_float(args[ARG_freq].u_obj));
+    }
+    #else
+    if (args[ARG_freq].u_int != 0xffffffff) {
+        self->period_ms = TIMER_MS_PER_TICK / ((uint64_t)args[ARG_freq].u_int);
+    }
+    #endif
+    else {
+        self->period_ms = args[ARG_period].u_int;
+    }
+
+    self->mode = args[ARG_mode].u_int;
+    self->callback = args[ARG_callback].u_obj;
+
+    k_timer_init(&self->my_timer, machine_timer_callback, NULL);
+    k_timer_user_data_set(&self->my_timer, self);
+    k_timer_start(&self->my_timer, K_MSEC(self->period_ms), K_MSEC(self->period_ms));
+
+    return mp_const_none;
+}
+
+static mp_obj_t machine_timer_deinit(mp_obj_t self_in) {
+    machine_timer_obj_t *self = self_in;
+    machine_timer_obj_t *prev = NULL;
+
+    k_timer_stop(&self->my_timer);
+
+    // remove it from the linked list
+    for (machine_timer_obj_t *_timer = MP_STATE_PORT(machine_timer_obj_head); _timer != NULL; _timer = _timer->next) {
+        if (_timer == self) {
+            if (prev != NULL) {
+                prev->next = _timer->next;
+            } else {
+                // move the start pointer
+                MP_STATE_PORT(machine_timer_obj_head) = _timer->next;
+            }
+            break;
+        } else {
+            prev = _timer;
+        }
+    }
+
+    return mp_const_none;
+}
+static MP_DEFINE_CONST_FUN_OBJ_1(machine_timer_deinit_obj, machine_timer_deinit);
+
+static mp_obj_t machine_timer_init(size_t n_args, const mp_obj_t *args, mp_map_t *kw_args) {
+    return machine_timer_init_helper(args[0], n_args - 1, args + 1, kw_args);
+}
+static MP_DEFINE_CONST_FUN_OBJ_KW(machine_timer_init_obj, 1, machine_timer_init);
+
+static mp_obj_t machine_timer_value(mp_obj_t self_in) {
+    machine_timer_obj_t *self = self_in;
+    k_ticks_t ticks = k_timer_remaining_ticks(&self->my_timer);
+    return MP_OBJ_NEW_SMALL_INT(k_ticks_to_ms_near32(ticks));
+}
+static MP_DEFINE_CONST_FUN_OBJ_1(machine_timer_value_obj, machine_timer_value);
+
+static const mp_rom_map_elem_t machine_timer_locals_dict_table[] = {
+    { MP_ROM_QSTR(MP_QSTR___del__),     MP_ROM_PTR(&machine_timer_deinit_obj) },
+    { MP_ROM_QSTR(MP_QSTR_deinit),      MP_ROM_PTR(&machine_timer_deinit_obj) },
+    { MP_ROM_QSTR(MP_QSTR_init),        MP_ROM_PTR(&machine_timer_init_obj) },
+    { MP_ROM_QSTR(MP_QSTR_value),       MP_ROM_PTR(&machine_timer_value_obj) },
+    { MP_ROM_QSTR(MP_QSTR_ONE_SHOT),    MP_ROM_INT(TIMER_MODE_ONE_SHOT) },
+    { MP_ROM_QSTR(MP_QSTR_PERIODIC),    MP_ROM_INT(TIMER_MODE_PERIODIC) },
+};
+static MP_DEFINE_CONST_DICT(machine_timer_locals_dict, machine_timer_locals_dict_table);
+
+MP_DEFINE_CONST_OBJ_TYPE(
+    machine_timer_type,
+    MP_QSTR_Timer,
+    MP_TYPE_FLAG_NONE,
+    make_new, machine_timer_make_new,
+    print, machine_timer_print,
+    locals_dict, &machine_timer_locals_dict
+    );
+
+MP_REGISTER_ROOT_POINTER(struct _machine_timer_obj_t *machine_timer_obj_head);
diff --git a/ports/zephyr/modmachine.c b/ports/zephyr/modmachine.c
index bbb9280a5..89ad12f18 100644
--- a/ports/zephyr/modmachine.c
+++ b/ports/zephyr/modmachine.c
@@ -44,6 +44,7 @@
     MICROPY_PY_MACHINE_RESET_ENTRY \
     { MP_ROM_QSTR(MP_QSTR_reset_cause), MP_ROM_PTR(&machine_reset_cause_obj) }, \
     { MP_ROM_QSTR(MP_QSTR_Pin), MP_ROM_PTR(&machine_pin_type) }, \
+    { MP_ROM_QSTR(MP_QSTR_Timer), MP_ROM_PTR(&machine_timer_type) }, \
 
 static mp_obj_t machine_reset(void) {
     sys_reboot(SYS_REBOOT_COLD);