stmhal - add pin mapping, gpio, exti, usrsw

1 files changed, 346 insertions, 0 deletions

diff --git a/stmhal/exti.c b/stmhal/exti.c
new file mode 100644
index 0000000000..ec6d82e4fd
--- /dev/null
+++ b/stmhal/exti.c
@@ -0,0 +1,346 @@
+#include <stdio.h>
+#include <stddef.h>
+#include <string.h>
+
+#include <stm32f4xx_hal.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_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.
+
+#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
+};
+
+// 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, 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 (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_jump(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_jump(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "Invalid EXTI Pull: %d", pull));
+    }
+
+    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);
+
+    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_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_RISING",            GPIO_MODE_IT_RISING },
+    { "MODE_IRQ_FALLING",           GPIO_MODE_IT_FALLING },
+    { "MODE_IRQ_RISING_FALLING",    GPIO_MODE_IT_RISING_FALLING },
+    { "MODE_EVT_RISING",            GPIO_MODE_EVT_RISING },
+    { "MODE_EVT_FALLING",           GPIO_MODE_EVT_FALLING },
+    { "MODE_EVT_RISING_FALLING",    GPIO_MODE_EVT_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,
+};
+
+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(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 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) {
+                rt_call_function_1(v->callback_obj, MP_OBJ_NEW_SMALL_INT(line));
+            }
+        }
+    }
+}