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circuitpython/stm/exti.c

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#include <stdio.h>
#include <stddef.h>
#include <string.h>
#include <stm32f4xx.h>
#include <stm32f4xx_gpio.h>
#include "misc.h"
#include "mpconfig.h"
#include "qstr.h"
#include "obj.h"
#include "runtime.h"
#include "nlr.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)
//
// # Configure the pin as a GPIO input.
// pin = pyb.Pin.board.X1
// pyb.gpio_in(pin, pyb.PULL_UP)
// exti = pyb.Exti(pin, pyb.Exti.MODE_IRQ, pyb.Exti.TRIGGER_RISING, callback, 37)
//
// Now every time a rising 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.
//
// Valid modes are pyb.Exti.MODE_IRQ and pyb.Exti.MODE_EVENT (Only MODE_IRQ
// has been tested. MODE_EVENT has something to do with sleep mode and the
// WFE instruction).
//
// Valid edge triggers are pyb.Exti.TRIGGER_RISING, TRIGGER_FALLING, and TRIGGER_BOTH.
//
// 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.
#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) (*(vu32 *)(PERIPH_BB_BASE + ((EXTI_OFFSET + (mode)) * 32) + ((line) * 4)))
// This macro will work with the EXTI_Trigger_Rising and EXTI_Trigger_Falling constants
// but not EXTI_Trigger_Rising_Falling.
#define EXTI_EDGE_BB(edge, line) (*(vu32 *)(PERIPH_BB_BASE + ((EXTI_OFFSET + (edge)) * 32) + ((line) * 4)))
#define EXTI_SWIER_BB(line) (*(vu32 *)(PERIPH_BB_BASE + ((EXTI_OFFSET + offsetof(EXTI_TypeDef, SWIER)) * 32) + ((line) * 4)))
#define EXTI_PR_BB(line) (*(vu32 *)(PERIPH_BB_BASE + ((EXTI_OFFSET + offsetof(EXTI_TypeDef, PR)) * 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;
EXTIMode_TypeDef mode;
} exti_vector_t;
static exti_vector_t exti_vector[EXTI_NUM_VECTORS];
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
};
// 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 trigger_obj, mp_obj_t 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_jump(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_jump(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 (!IS_EXTI_MODE(mode)) {
nlr_jump(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "Invalid EXTI Mode: %d", mode));
}
int trigger = mp_obj_get_int(trigger_obj);
if (!IS_EXTI_TRIGGER(trigger)) {
nlr_jump(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "Invalid EXTI Trigger: %d", trigger));
}
exti_vector_t *v = &exti_vector[v_line];
if (v->callback_obj != mp_const_none && callback_obj != mp_const_none) {
nlr_jump(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);
if (pin && callback_obj) {
// Enable SYSCFG clock
RCC_APB2PeriphClockCmd(RCC_APB2Periph_SYSCFG, ENABLE);
// For EXTI lines 0 thru 15, we need to configure which port controls
// the line.
SYSCFG_EXTILineConfig(pin->port, v_line);
}
v->callback_obj = callback_obj;
v->param = param;
v->mode = mode;
if (v->callback_obj != mp_const_none) {
// The EXTI_Init function isn't atomic. It uses |= and &=.
// We use bit band operations to make it atomic.
EXTI_EDGE_BB(EXTI_Trigger_Rising, v_line) =
trigger == EXTI_Trigger_Rising || trigger == EXTI_Trigger_Rising_Falling;
EXTI_EDGE_BB(EXTI_Trigger_Falling, v_line) =
trigger == EXTI_Trigger_Falling || trigger == EXTI_Trigger_Rising_Falling;
exti_enable(v_line);
/* Enable and set NVIC Interrupt to the lowest priority */
NVIC_InitTypeDef NVIC_InitStructure;
NVIC_InitStructure.NVIC_IRQChannel = nvic_irq_channel[v_line];
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x0F;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x0F;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
}
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_BB(line) = 1;
}
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_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 const mp_method_t exti_methods[] = {
{ "line", &exti_obj_line_obj },
{ "enable", &exti_obj_enable_obj },
{ "disable", &exti_obj_disable_obj },
{ "swint", &exti_obj_swint_obj },
{ NULL, NULL },
};
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_0(exti_regs_obj, exti_regs);
typedef struct {
const char *name;
uint val;
} exti_const_t;
static const exti_const_t exti_const[] = {
{ "MODE_IRQ", EXTI_Mode_Interrupt },
{ "MODE_EVENT", EXTI_Mode_Event },
{ "TRIGGER_RISING", EXTI_Trigger_Rising },
{ "TRIGGER_FALLING", EXTI_Trigger_Falling },
{ "TRIGGER_BOTH", EXTI_Trigger_Rising_Falling },
};
#define EXTI_NUM_CONST (sizeof(exti_const) / sizeof(exti_const[0]))
static void exti_load_attr(mp_obj_t self_in, qstr attr_qstr, mp_obj_t *dest) {
(void)self_in;
const char *attr = qstr_str(attr_qstr);
if (strcmp(attr, "regs") == 0) {
dest[0] = (mp_obj_t)&exti_regs_obj;
return;
}
const exti_const_t *entry = &exti_const[0];
for (; entry < &exti_const[EXTI_NUM_CONST]; entry++) {
if (strcmp(attr, entry->name) == 0) {
dest[0] = MP_OBJ_NEW_SMALL_INT(entry->val);
dest[1] = MP_OBJ_NULL;
return;
}
}
}
// line_obj = pyb.Exti(pin, mode, trigger, callback)
static mp_obj_t exti_call(mp_obj_t type_in, uint n_args, uint n_kw, const mp_obj_t *args) {
// type_in == exti_obj_type
rt_check_nargs(n_args, 4, 4, n_kw, 0);
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, NULL);
return self;
}
static void exti_meta_obj_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t self_in, mp_print_kind_t kind) {
(void) self_in;
print(env, "<Exti meta>");
}
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);
}
static const mp_obj_type_t exti_meta_obj_type = {
{ &mp_type_type },
.name = MP_QSTR_ExtiMeta,
.print = exti_meta_obj_print,
.call = exti_call,
.load_attr = exti_load_attr,
};
static const mp_obj_type_t exti_obj_type = {
{ &exti_meta_obj_type },
.name = MP_QSTR_Exti,
.print = exti_obj_print,
.methods = exti_methods,
};
void exti_init_early(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;
}
}
void exti_init(mp_obj_t mod) {
rt_store_attr(mod, MP_QSTR_Exti, (mp_obj_t)&exti_obj_type);
}
static void Handle_EXTI_Irq(uint32_t line) {
if (EXTI_PR_BB(line)) {
EXTI_PR_BB(line) = 1; // Clears bit
if (line < EXTI_NUM_VECTORS) {
exti_vector_t *v = &exti_vector[line];
if (v->callback_obj != mp_const_none) {
rt_call_function_1(v->callback_obj, MP_OBJ_NEW_SMALL_INT(line));
}
}
}
}
void EXTI0_IRQHandler(void) {
Handle_EXTI_Irq(0);
}
void EXTI1_IRQHandler(void) {
Handle_EXTI_Irq(1);
}
void EXTI2_IRQHandler(void) {
Handle_EXTI_Irq(2);
}
void EXTI3_IRQHandler(void) {
Handle_EXTI_Irq(3);
}
void EXTI4_IRQHandler(void) {
Handle_EXTI_Irq(4);
}
void EXTI9_5_IRQHandler(void) {
Handle_EXTI_Irq(5);
Handle_EXTI_Irq(6);
Handle_EXTI_Irq(7);
Handle_EXTI_Irq(8);
Handle_EXTI_Irq(9);
}
void EXTI15_10_IRQHandler(void) {
Handle_EXTI_Irq(10);
Handle_EXTI_Irq(11);
Handle_EXTI_Irq(12);
Handle_EXTI_Irq(13);
Handle_EXTI_Irq(14);
Handle_EXTI_Irq(15);
#if 0
// for CC3000 support, needs to be re-written to use new EXTI code
if (EXTI_GetITStatus(EXTI_Line14) != RESET) {
led_toggle(PYB_LED_G2);
/* these are needed for CC3000 support
extern void SpiIntGPIOHandler(void);
extern uint32_t exti14_enabled;
extern uint32_t exti14_missed;
//printf("-> EXTI14 en=%lu miss=%lu\n", exti14_enabled, exti14_missed);
if (exti14_enabled) {
exti14_missed = 0;
SpiIntGPIOHandler(); // CC3000 interrupt
} else {
exti14_missed = 1;
}
*/
EXTI_ClearITPendingBit(EXTI_Line14);
//printf("<- EXTI14 done\n");
}
#endif
}
void PVD_IRQHandler(void) {
Handle_EXTI_Irq(16);
}
void RTC_Alarm_IRQHandler(void) {
Handle_EXTI_Irq(17);
}
#if 0 // dealt with in stm32fxxx_it.c
void OTG_FS_WKUP_IRQHandler(void) {
Handle_EXTI_Irq(18);
}
#endif
void ETH_WKUP_IRQHandler(void) {
Handle_EXTI_Irq(19);
}
#if 0 // dealt with in stm32fxxx_it.c
void OTG_HS_WKUP_IRQHandler(void) {
Handle_EXTI_Irq(20);
}
#endif
void TAMP_STAMP_IRQHandler(void) {
Handle_EXTI_Irq(21);
}
void RTC_WKUP_IRQHandler(void) {
Handle_EXTI_Irq(22);
}
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