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circuitpython/stmhal/exti.c

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#include <stdio.h>
#include <stddef.h>
#include <string.h>
#include <stm32f4xx_hal.h>
#include "nlr.h"
#include "misc.h"
#include "mpconfig.h"
#include "qstr.h"
#include "gc.h"
#include "obj.h"
#include "runtime.h"
#include "pin.h"
#include "exti.h"
// Usage Model:
//
// There are a total of 22 interrupt lines. 16 of these can come from GPIO pins
// and the remaining 6 are from internal sources.
//
// For lines 0 thru 15, a given line can map to the corresponding line from an
// arbitrary port. So line 0 can map to Px0 where x is A, B, C, ... and
// line 1 can map to Px1 where x is A, B, C, ...
//
// def callback(line):
// print("line =", line)
//
// # Note: Exti will automatically configure the gpio line as an input.
// exti = pyb.Exti(pin, pyb.Exti.MODE_IRQ_FALLING, pyb.PULLUP, callback)
//
// Now every time a falling edge is seen on the X1 pin, the callback will be
// called. Caution: mechanical pushbuttons have "bounce" and pushing or
// releasing a switch will often generate multiple edges.
// See: http://www.eng.utah.edu/~cs5780/debouncing.pdf for a detailed
// explanation, along with various techniques for debouncing.
//
// Trying to register 2 callbacks onto the same pin will throw an exception.
//
// If pin is passed as an integer, then it is assumed to map to one of the
// internal interrupt sources, and must be in the range 16 thru 22.
//
// All other pin objects go through the pin mapper to come up with one of the
// gpio pins.
//
// exti = pyb.Exti(pin, mode, pull, callback)
//
// Valid modes are pyb.Exti.MODE_IRQ_RISING, pyb.Exti.MODE_IRQ_FALLING,
// pyb.Exti.MODE_IRQ_RISING_FALLING, pyb.Exti.MODE_EVT_RISING,
// pyb.Exti.MODE_EVT_FALLING, and pyb.Exti.MODE_EVT_RISING_FALLING.
//
// Only the MODE_IRQ_xxx modes have been tested. The MODE_EVENT_xxx modes have
// something to do with sleep mode and he WFE instruction.
//
// Valid pull values are pyb.PULL_UP, pyb.PULL_DOWN, pyb.PULL_NONE.
//
// exti.line() will return the line number that pin was mapped to.
// exti.disable() can be use to disable the interrupt associated with a given
// exti object. This could be useful for debouncing.
// exti.enable() enables a disabled interrupt
// exti.swint() will allow the callback to be triggered from software.
//
// pyb.Exti.regs() will dump the values of the EXTI registers.
//
// There is also a C API, so that drivers which require EXTI interrupt lines
// can also use this code. See exti.h for the available functions and
// usrsw.h for an example of using this.
//
// TODO Add python method to change callback object.
#define EXTI_OFFSET (EXTI_BASE - PERIPH_BASE)
// Macro used to set/clear the bit corresponding to the line in the IMR/EMR
// register in an atomic fashion by using bitband addressing.
#define EXTI_MODE_BB(mode, line) (*(__IO uint32_t *)(PERIPH_BB_BASE + ((EXTI_OFFSET + (mode)) * 32) + ((line) * 4)))
#define EXTI_Mode_Interrupt offsetof(EXTI_TypeDef, IMR)
#define EXTI_Mode_Event offsetof(EXTI_TypeDef, EMR)
#define EXTI_SWIER_BB(line) (*(__IO uint32_t *)(PERIPH_BB_BASE + ((EXTI_OFFSET + offsetof(EXTI_TypeDef, SWIER)) * 32) + ((line) * 4)))
typedef struct {
mp_obj_base_t base;
mp_small_int_t line;
} exti_obj_t;
typedef struct {
mp_obj_t callback_obj;
void *param;
uint32_t mode;
} exti_vector_t;
STATIC exti_vector_t exti_vector[EXTI_NUM_VECTORS];
#if !defined(ETH)
#define ETH_WKUP_IRQn 62 // The 405 doesn't have ETH, but we want a value to put in our table
#endif
STATIC const uint8_t nvic_irq_channel[EXTI_NUM_VECTORS] = {
EXTI0_IRQn, EXTI1_IRQn, EXTI2_IRQn, EXTI3_IRQn, EXTI4_IRQn,
EXTI9_5_IRQn, EXTI9_5_IRQn, EXTI9_5_IRQn, EXTI9_5_IRQn, EXTI9_5_IRQn,
EXTI15_10_IRQn, EXTI15_10_IRQn, EXTI15_10_IRQn, EXTI15_10_IRQn, EXTI15_10_IRQn,
EXTI15_10_IRQn, PVD_IRQn, RTC_Alarm_IRQn, OTG_FS_WKUP_IRQn, ETH_WKUP_IRQn,
OTG_HS_WKUP_IRQn, TAMP_STAMP_IRQn, RTC_WKUP_IRQn
};
// Set override_callback_obj to true if you want to unconditionally set the
// callback function.
//
// NOTE: param is for C callers. Python can use closure to get an object bound
// with the function.
uint exti_register(mp_obj_t pin_obj, mp_obj_t mode_obj, mp_obj_t pull_obj, mp_obj_t callback_obj, bool override_callback_obj, void *param) {
const pin_obj_t *pin = NULL;
uint v_line;
if (MP_OBJ_IS_INT(pin_obj)) {
// If an integer is passed in, then use it to identify lines 16 thru 22
// We expect lines 0 thru 15 to be passed in as a pin, so that we can
// get both the port number and line number.
v_line = mp_obj_get_int(pin_obj);
if (v_line < 16) {
nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "EXTI vector %d < 16, use a Pin object", v_line));
}
if (v_line >= EXTI_NUM_VECTORS) {
nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "EXTI vector %d >= max of %d", v_line, EXTI_NUM_VECTORS));
}
} else {
pin = pin_map_user_obj(pin_obj);
v_line = pin->pin;
}
int mode = mp_obj_get_int(mode_obj);
if (mode != GPIO_MODE_IT_RISING &&
mode != GPIO_MODE_IT_FALLING &&
mode != GPIO_MODE_IT_RISING_FALLING &&
mode != GPIO_MODE_EVT_RISING &&
mode != GPIO_MODE_EVT_FALLING &&
mode != GPIO_MODE_EVT_RISING_FALLING) {
nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "Invalid EXTI Mode: %d", mode));
}
int pull = mp_obj_get_int(pull_obj);
if (pull != GPIO_NOPULL &&
pull != GPIO_PULLUP &&
pull != GPIO_PULLDOWN) {
nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "Invalid EXTI Pull: %d", pull));
}
exti_vector_t *v = &exti_vector[v_line];
if (!override_callback_obj && v->callback_obj != mp_const_none && callback_obj != mp_const_none) {
nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "EXTI vector %d is already in use", v_line));
}
// We need to update callback and param atomically, so we disable the line
// before we update anything.
exti_disable(v_line);
v->callback_obj = callback_obj;
v->param = param;
v->mode = (mode & 0x00010000) ? // GPIO_MODE_IT == 0x00010000
EXTI_Mode_Interrupt : EXTI_Mode_Event;
if (v->callback_obj != mp_const_none) {
GPIO_InitTypeDef exti;
exti.Pin = pin->pin_mask;
exti.Mode = mode;
exti.Pull = pull;
exti.Speed = GPIO_SPEED_FAST;
HAL_GPIO_Init(pin->gpio, &exti);
// Calling HAL_GPIO_Init does an implicit exti_enable
/* Enable and set NVIC Interrupt to the lowest priority */
HAL_NVIC_SetPriority(nvic_irq_channel[v_line], 0x0F, 0x0F);
HAL_NVIC_EnableIRQ(nvic_irq_channel[v_line]);
}
return v_line;
}
void exti_enable(uint line) {
if (line >= EXTI_NUM_VECTORS) {
return;
}
// Since manipulating IMR/EMR is a read-modify-write, and we want this to
// be atomic, we use the bit-band area to just affect the bit we're
// interested in.
EXTI_MODE_BB(exti_vector[line].mode, line) = 1;
}
void exti_disable(uint line) {
if (line >= EXTI_NUM_VECTORS) {
return;
}
// Since manipulating IMR/EMR is a read-modify-write, and we want this to
// be atomic, we use the bit-band area to just affect the bit we're
// interested in.
EXTI_MODE_BB(EXTI_Mode_Interrupt, line) = 0;
EXTI_MODE_BB(EXTI_Mode_Event, line) = 0;
}
void exti_swint(uint line) {
if (line >= EXTI_NUM_VECTORS) {
return;
}
EXTI->SWIER = (1 << line);
}
STATIC mp_obj_t exti_obj_line(mp_obj_t self_in) {
exti_obj_t *self = self_in;
return MP_OBJ_NEW_SMALL_INT(self->line);
}
STATIC mp_obj_t exti_obj_enable(mp_obj_t self_in) {
exti_obj_t *self = self_in;
exti_enable(self->line);
return mp_const_none;
}
STATIC mp_obj_t exti_obj_disable(mp_obj_t self_in) {
exti_obj_t *self = self_in;
exti_disable(self->line);
return mp_const_none;
}
STATIC mp_obj_t exti_obj_swint(mp_obj_t self_in) {
exti_obj_t *self = self_in;
exti_swint(self->line);
return mp_const_none;
}
STATIC mp_obj_t exti_regs(void) {
printf("EXTI_IMR %08lx\n", EXTI->IMR);
printf("EXTI_EMR %08lx\n", EXTI->EMR);
printf("EXTI_RTSR %08lx\n", EXTI->RTSR);
printf("EXTI_FTSR %08lx\n", EXTI->FTSR);
printf("EXTI_SWIER %08lx\n", EXTI->SWIER);
printf("EXTI_PR %08lx\n", EXTI->PR);
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(exti_obj_line_obj, exti_obj_line);
STATIC MP_DEFINE_CONST_FUN_OBJ_1(exti_obj_enable_obj, exti_obj_enable);
STATIC MP_DEFINE_CONST_FUN_OBJ_1(exti_obj_disable_obj, exti_obj_disable);
STATIC MP_DEFINE_CONST_FUN_OBJ_1(exti_obj_swint_obj, exti_obj_swint);
STATIC MP_DEFINE_CONST_FUN_OBJ_0(exti_regs_fun_obj, exti_regs);
STATIC MP_DEFINE_CONST_STATICMETHOD_OBJ(exti_regs_obj, (mp_obj_t)&exti_regs_fun_obj);
STATIC const mp_map_elem_t exti_locals_dict_table[] = {
{ MP_OBJ_NEW_QSTR(MP_QSTR_line), (mp_obj_t)&exti_obj_line_obj },
{ MP_OBJ_NEW_QSTR(MP_QSTR_enable), (mp_obj_t)&exti_obj_enable_obj },
{ MP_OBJ_NEW_QSTR(MP_QSTR_disable), (mp_obj_t)&exti_obj_disable_obj },
{ MP_OBJ_NEW_QSTR(MP_QSTR_swint), (mp_obj_t)&exti_obj_swint_obj },
{ MP_OBJ_NEW_QSTR(MP_QSTR_regs), (mp_obj_t)&exti_regs_obj },
{ MP_OBJ_NEW_QSTR(MP_QSTR_MODE_IRQ_RISING), MP_OBJ_NEW_SMALL_INT(GPIO_MODE_IT_RISING) },
{ MP_OBJ_NEW_QSTR(MP_QSTR_MODE_IRQ_FALLING), MP_OBJ_NEW_SMALL_INT(GPIO_MODE_IT_FALLING) },
{ MP_OBJ_NEW_QSTR(MP_QSTR_MODE_IRQ_RISING_FALLING), MP_OBJ_NEW_SMALL_INT(GPIO_MODE_IT_RISING_FALLING) },
{ MP_OBJ_NEW_QSTR(MP_QSTR_MODE_EVT_RISING), MP_OBJ_NEW_SMALL_INT(GPIO_MODE_EVT_RISING) },
{ MP_OBJ_NEW_QSTR(MP_QSTR_MODE_EVT_FALLING), MP_OBJ_NEW_SMALL_INT(GPIO_MODE_EVT_FALLING) },
{ MP_OBJ_NEW_QSTR(MP_QSTR_MODE_EVT_RISING_FALLING), MP_OBJ_NEW_SMALL_INT(GPIO_MODE_EVT_RISING_FALLING) },
};
STATIC MP_DEFINE_CONST_DICT(exti_locals_dict, exti_locals_dict_table);
// line_obj = pyb.Exti(pin, mode, trigger, callback)
STATIC mp_obj_t exti_make_new(mp_obj_t type_in, uint n_args, uint n_kw, const mp_obj_t *args) {
// type_in == exti_obj_type
mp_check_nargs(n_args, 4, 4, n_kw, false);
exti_obj_t *self = m_new_obj(exti_obj_t);
self->base.type = type_in;
mp_obj_t line_obj = args[0];
mp_obj_t mode_obj = args[1];
mp_obj_t trigger_obj = args[2];
mp_obj_t callback_obj = args[3];
self->line = exti_register(line_obj, mode_obj, trigger_obj, callback_obj, false, NULL);
return self;
}
STATIC void exti_obj_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t self_in, mp_print_kind_t kind) {
exti_obj_t *self = self_in;
print(env, "<Exti line=%u>", self->line);
}
const mp_obj_type_t exti_obj_type = {
{ &mp_type_type },
.name = MP_QSTR_Exti,
.print = exti_obj_print,
.make_new = exti_make_new,
.locals_dict = (mp_obj_t)&exti_locals_dict,
};
void exti_init(void) {
for (exti_vector_t *v = exti_vector; v < &exti_vector[EXTI_NUM_VECTORS]; v++) {
v->callback_obj = mp_const_none;
v->param = NULL;
v->mode = EXTI_Mode_Interrupt;
}
}
// Interrupt handler
void Handle_EXTI_Irq(uint32_t line) {
if (__HAL_GPIO_EXTI_GET_FLAG(1 << line)) {
__HAL_GPIO_EXTI_CLEAR_FLAG(1 << line);
if (line < EXTI_NUM_VECTORS) {
exti_vector_t *v = &exti_vector[line];
if (v->callback_obj != mp_const_none) {
// When executing code within a handler we must lock the GC to prevent
// any memory allocations. We must also catch any exceptions.
gc_lock();
nlr_buf_t nlr;
if (nlr_push(&nlr) == 0) {
mp_call_function_1(v->callback_obj, MP_OBJ_NEW_SMALL_INT(line));
nlr_pop();
} else {
// Uncaught exception; disable the callback so it doesn't run again.
v->callback_obj = mp_const_none;
exti_disable(line);
printf("Uncaught exception in EXTI interrupt handler line %lu\n", line);
mp_obj_print_exception((mp_obj_t)nlr.ret_val);
}
gc_unlock();
}
}
}
}
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