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Diffstat (limited to 'stm/exti.c')
| -rw-r--r-- | stm/exti.c | 417 |
1 files changed, 417 insertions, 0 deletions
diff --git a/stm/exti.c b/stm/exti.c new file mode 100644 index 0000000000..6b0711a715 --- /dev/null +++ b/stm/exti.c @@ -0,0 +1,417 @@ +#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, param): +// print("line =", line, "param =", param) +// +// # 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; + mp_obj_t param_obj; + 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 +}; + +uint exti_register(mp_obj_t pin_obj, mp_obj_t mode_obj, mp_obj_t trigger_obj, mp_obj_t callback_obj, mp_obj_t param_obj) { + 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_obj = param_obj; + 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_disable(v_line); + 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, [param]) + +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, 5, 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]; + mp_obj_t param_obj = mp_const_none; + if (n_args > 4) { + param_obj = args[4]; + } + self->line = exti_register(line_obj, mode_obj, trigger_obj, callback_obj, param_obj); + + 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_obj = mp_const_none; + 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_2(v->callback_obj, MP_OBJ_NEW_SMALL_INT(line), v->param_obj); + } + } + } +} + +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); +} + +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); +} |