samd/machine_timer: Add machine.Timer based on the shared soft-timer.

Author: robert-hh

ports/samd/Makefile

@@ -95,12 +95,14 @@ SRC_C = \
 	machine_led.c \
 	machine_pin.c \
 	machine_spi.c \
+	machine_timer.c \
 	machine_uart.c \
 	main.c \
 	modutime.c \
 	modmachine.c \
 	modsamd.c \
 	mphalport.c \
+	pendsv.c \
 	pin_af.c \
 	$(BUILD)/pins.c \
 	samd_flash.c \
@@ -128,6 +130,7 @@ SRC_C = \
 	shared/readline/readline.c \
 	shared/runtime/gchelper_native.c \
 	shared/runtime/pyexec.c \
+	shared/runtime/softtimer.c \
 	shared/runtime/stdout_helpers.c \
 	shared/runtime/sys_stdio_mphal.c \
 	shared/timeutils/timeutils.c \
@@ -150,6 +153,7 @@ SRC_QSTR += \
 	machine_pin.c \
 	machine_pwm.c \
 	machine_spi.c \
+	machine_timer.c \
 	machine_uart.c \
 	modutime.c \
 	modmachine.c \

ports/samd/boards/mpconfig_samd21.h

@@ -7,3 +7,14 @@
 
 #define CPU_FREQ            (48000000)
 #define APB_FREQ            (48000000)
+
+#define IRQ_PRI_PENDSV          ((1 << __NVIC_PRIO_BITS) - 1)
+
+static inline uint32_t raise_irq_pri(uint32_t pri) {
+    (void)pri;
+    return 0;
+}
+
+static inline void restore_irq_pri(uint32_t basepri) {
+    (void)basepri;
+}

ports/samd/boards/mpconfig_samd51.h

@@ -22,3 +22,23 @@ unsigned long trng_random_u32(void);
 #define CPU_FREQ            (120000000)
 #define APB_FREQ            (48000000)
 #define DPLLx_REF_FREQ      (32768)
+
+#define NVIC_PRIORITYGROUP_4    ((uint32_t)0x00000003)
+#define IRQ_PRI_PENDSV          NVIC_EncodePriority(NVIC_PRIORITYGROUP_4, 7, 0)
+
+static inline uint32_t raise_irq_pri(uint32_t pri) {
+    uint32_t basepri = __get_BASEPRI();
+    // If non-zero, the processor does not process any exception with a
+    // priority value greater than or equal to BASEPRI.
+    // When writing to BASEPRI_MAX the write goes to BASEPRI only if either:
+    //   - Rn is non-zero and the current BASEPRI value is 0
+    //   - Rn is non-zero and less than the current BASEPRI value
+    pri <<= (8 - __NVIC_PRIO_BITS);
+    __ASM volatile ("msr basepri_max, %0" : : "r" (pri) : "memory");
+    return basepri;
+}
+
+// "basepri" should be the value returned from raise_irq_pri
+static inline void restore_irq_pri(uint32_t basepri) {
+    __set_BASEPRI(basepri);
+}

ports/samd/machine_timer.c

@@ -0,0 +1,146 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2019 Damien P. George
+ *
+ * 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 "py/runtime.h"
+#include "py/mphal.h"
+#include "shared/runtime/softtimer.h"
+
+typedef soft_timer_entry_t machine_timer_obj_t;
+
+const mp_obj_type_t machine_timer_type;
+
+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 = MP_OBJ_TO_PTR(self_in);
+    qstr mode = self->mode == SOFT_TIMER_MODE_ONE_SHOT ? MP_QSTR_ONE_SHOT : MP_QSTR_PERIODIC;
+    mp_printf(print, "Timer(mode=%q, period=%u)", mode, self->delta_ms);
+}
+
+STATIC mp_obj_t machine_timer_init_helper(machine_timer_obj_t *self, size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
+    enum { ARG_mode, ARG_callback, ARG_period, ARG_tick_hz, ARG_freq, };
+    static const mp_arg_t allowed_args[] = {
+        { MP_QSTR_mode,         MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = SOFT_TIMER_MODE_PERIODIC} },
+        { MP_QSTR_callback,     MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
+        { MP_QSTR_period,       MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0xffffffff} },
+        { MP_QSTR_tick_hz,      MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 1000} },
+        { MP_QSTR_freq,         MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_rom_obj = MP_ROM_NONE} },
+    };
+
+    // Parse args
+    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);
+
+    self->mode = args[ARG_mode].u_int;
+
+    uint64_t delta_ms = self->delta_ms;
+    if (args[ARG_freq].u_obj != mp_const_none) {
+        // Frequency specified in Hz
+        #if MICROPY_PY_BUILTINS_FLOAT
+        delta_ms = (uint32_t)(MICROPY_FLOAT_CONST(1000.0) / mp_obj_get_float(args[ARG_freq].u_obj));
+        #else
+        delta_ms = 1000 / mp_obj_get_int(args[ARG_freq].u_obj);
+        #endif
+    } else if (args[ARG_period].u_int != 0xffffffff) {
+        // Period specified
+        delta_ms = (uint64_t)args[ARG_period].u_int * 1000 / args[ARG_tick_hz].u_int;
+    }
+
+    if (delta_ms < 1) {
+        delta_ms = 1;
+    } else if (delta_ms >= 0x40000000) {
+        mp_raise_ValueError(MP_ERROR_TEXT("period too large"));
+    }
+    self->delta_ms = (uint32_t)delta_ms;
+
+    if (args[ARG_callback].u_obj != MP_OBJ_NULL) {
+        self->py_callback = args[ARG_callback].u_obj;
+    }
+
+    if (self->py_callback != mp_const_none) {
+        soft_timer_insert(self, self->delta_ms);
+    }
+
+    return mp_const_none;
+}
+
+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) {
+    machine_timer_obj_t *self = m_new_obj(machine_timer_obj_t);
+    self->pairheap.base.type = &machine_timer_type;
+    self->flags = SOFT_TIMER_FLAG_PY_CALLBACK | SOFT_TIMER_FLAG_GC_ALLOCATED;
+    self->delta_ms = 1000;
+    self->py_callback = mp_const_none;
+
+    // Get timer id (only soft timer (-1) supported at the moment)
+    mp_int_t id = -1;
+    if (n_args > 0) {
+        id = mp_obj_get_int(args[0]);
+        --n_args;
+        ++args;
+    }
+    if (id != -1) {
+        mp_raise_ValueError(MP_ERROR_TEXT("Timer doesn't exist"));
+    }
+
+    if (n_args > 0 || n_kw > 0) {
+        // Start the timer
+        mp_map_t kw_args;
+        mp_map_init_fixed_table(&kw_args, n_kw, args + n_args);
+        machine_timer_init_helper(self, n_args, args, &kw_args);
+    }
+
+    return MP_OBJ_FROM_PTR(self);
+}
+
+STATIC mp_obj_t machine_timer_init(size_t n_args, const mp_obj_t *args, mp_map_t *kw_args) {
+    machine_timer_obj_t *self = MP_OBJ_TO_PTR(args[0]);
+    soft_timer_remove(self);
+    return machine_timer_init_helper(self, 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_deinit(mp_obj_t self_in) {
+    machine_timer_obj_t *self = MP_OBJ_TO_PTR(self_in);
+    soft_timer_remove(self);
+    return mp_const_none;
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_1(machine_timer_deinit_obj, machine_timer_deinit);
+
+STATIC const mp_rom_map_elem_t machine_timer_locals_dict_table[] = {
+    { MP_ROM_QSTR(MP_QSTR_init), MP_ROM_PTR(&machine_timer_init_obj) },
+    { MP_ROM_QSTR(MP_QSTR_deinit), MP_ROM_PTR(&machine_timer_deinit_obj) },
+
+    { MP_ROM_QSTR(MP_QSTR_ONE_SHOT), MP_ROM_INT(SOFT_TIMER_MODE_ONE_SHOT) },
+    { MP_ROM_QSTR(MP_QSTR_PERIODIC), MP_ROM_INT(SOFT_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
+    );

ports/samd/main.c

@@ -31,6 +31,7 @@
 #include "py/stackctrl.h"
 #include "shared/runtime/gchelper.h"
 #include "shared/runtime/pyexec.h"
+#include "shared/runtime/softtimer.h"
 
 extern uint8_t _sstack, _estack, _sheap, _eheap;
 extern void adc_deinit_all(void);
@@ -82,6 +83,7 @@ void samd_main(void) {
         pwm_deinit_all();
         sercom_deinit_all();
         uart_deinit_all();
+        soft_timer_deinit();
         gc_sweep_all();
         mp_deinit();
     }

ports/samd/modmachine.c

@@ -157,6 +157,7 @@ STATIC const mp_rom_map_elem_t machine_module_globals_table[] = {
     { MP_ROM_QSTR(MP_QSTR_I2C),                 MP_ROM_PTR(&machine_hw_i2c_type) },
     { MP_ROM_QSTR(MP_QSTR_SoftSPI),             MP_ROM_PTR(&mp_machine_soft_spi_type) },
     { MP_ROM_QSTR(MP_QSTR_SPI),                 MP_ROM_PTR(&machine_spi_type) },
+    { MP_ROM_QSTR(MP_QSTR_Timer),               MP_ROM_PTR(&machine_timer_type) },
     { MP_ROM_QSTR(MP_QSTR_UART),                MP_ROM_PTR(&machine_uart_type) },
 
     { MP_ROM_QSTR(MP_QSTR_idle),                MP_ROM_PTR(&machine_idle_obj) },

ports/samd/modmachine.h

@@ -34,6 +34,7 @@ extern const mp_obj_type_t machine_led_type;
 extern const mp_obj_type_t machine_pin_type;
 extern const mp_obj_type_t machine_pwm_type;
 extern const mp_obj_type_t machine_spi_type;
+extern const mp_obj_type_t machine_timer_type;
 extern const mp_obj_type_t machine_uart_type;
 
 #endif // MICROPY_INCLUDED_SAMD_MODMACHINE_H

ports/samd/mphalport.h

@@ -40,6 +40,10 @@ extern volatile uint32_t systick_ms_upper;
 
 void mp_hal_set_interrupt_char(int c);
 
+// Define an alias fo systick_ms, because the shared softtimer.c uses
+// the symbol uwTick for the systick ms counter.
+#define uwTick systick_ms
+
 #define mp_hal_delay_us_fast  mp_hal_delay_us
 
 static inline mp_uint_t mp_hal_ticks_ms(void) {

ports/samd/pendsv.c

@@ -0,0 +1,71 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2013, 2014 Damien P. George
+ *
+ * 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 <stdlib.h>
+
+#include "py/runtime.h"
+#include "shared/runtime/interrupt_char.h"
+#include "sam.h"
+#include "pendsv.h"
+
+
+#if defined(PENDSV_DISPATCH_NUM_SLOTS)
+uint32_t pendsv_dispatch_active;
+pendsv_dispatch_t pendsv_dispatch_table[PENDSV_DISPATCH_NUM_SLOTS];
+#endif
+
+void pendsv_init(void) {
+    #if defined(PENDSV_DISPATCH_NUM_SLOTS)
+    pendsv_dispatch_active = false;
+    #endif
+
+    // set PendSV interrupt at lowest priority
+    NVIC_SetPriority(PendSV_IRQn, IRQ_PRI_PENDSV);
+}
+
+#if defined(PENDSV_DISPATCH_NUM_SLOTS)
+void pendsv_schedule_dispatch(size_t slot, pendsv_dispatch_t f) {
+    pendsv_dispatch_table[slot] = f;
+    pendsv_dispatch_active = true;
+    SCB->ICSR = SCB_ICSR_PENDSVSET_Msk;
+}
+
+void pendsv_dispatch_handler(void) {
+    for (size_t i = 0; i < PENDSV_DISPATCH_NUM_SLOTS; ++i) {
+        if (pendsv_dispatch_table[i] != NULL) {
+            pendsv_dispatch_t f = pendsv_dispatch_table[i];
+            pendsv_dispatch_table[i] = NULL;
+            f();
+        }
+    }
+}
+
+void PendSV_Handler(void) {
+    if (pendsv_dispatch_active) {
+        pendsv_dispatch_handler();
+    }
+}
+#endif

ports/samd/pendsv.h

@@ -0,0 +1,41 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2013, 2014 Damien P. George
+ *
+ * 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.
+ */
+#ifndef MICROPY_INCLUDED_SAMD_PENDSV_H
+#define MICROPY_INCLUDED_SAMD_PENDSV_H
+
+enum {
+    PENDSV_DISPATCH_SOFT_TIMER,  // For later & for having at least one entry
+    PENDSV_DISPATCH_MAX
+};
+
+#define PENDSV_DISPATCH_NUM_SLOTS PENDSV_DISPATCH_MAX
+
+typedef void (*pendsv_dispatch_t)(void);
+
+void pendsv_init(void);
+void pendsv_schedule_dispatch(size_t slot, pendsv_dispatch_t f);
+
+#endif // MICROPY_INCLUDED_SAMD_PENDSV_H