samd/modsamd: Add pininfo() function to the samd module.

samd.pininfo() returns the data stored in the pin af table for a pin.
Using a small script, a nice representation of the table can be created.

ports/samd/machine_pin.c

@@ -92,7 +92,6 @@ int pin_find(mp_obj_t pin, const machine_pin_obj_t machine_pin_obj[], int table_
     return wanted_pin;
 }
 
-
 // Pin.init(mode, pull=None, *, value=None, drive=0). No 'alt' yet.
 STATIC mp_obj_t machine_pin_obj_init_helper(const machine_pin_obj_t *self, size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
     enum { ARG_mode, ARG_pull, ARG_value, ARG_drive, ARG_alt };
@@ -157,7 +156,6 @@ mp_obj_t mp_pin_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw,
     if (self == NULL || self->base.type == NULL) {
         mp_raise_ValueError(MP_ERROR_TEXT("invalid pin"));
     }
-    self = (machine_pin_obj_t *)&machine_pin_obj[wanted_pin];
 
     if (n_args > 1 || n_kw > 0) {
         // pin mode given, so configure this GPIO

ports/samd/modsamd.c

@@ -24,14 +24,56 @@
  * THE SOFTWARE.
  */
 
+#include "string.h"
 #include "py/runtime.h"
+#include "py/mphal.h"
+
+#include "sam.h"
+#include "pin_af.h"
+#include "pins.h"
 #include "samd_soc.h"
 
 extern const mp_obj_type_t samd_flash_type;
 
+STATIC mp_obj_t samd_pininfo(mp_obj_t pin_obj) {
+    mp_hal_pin_obj_t pin = mp_hal_get_pin_obj(pin_obj);
+    const pin_af_t *pin_af = get_pin_af_info(pin);
+    const char *name = ((machine_pin_obj_t *)MP_OBJ_TO_PTR(pin_obj))->name;
+    if (pin_af) {
+        #if defined(MCU_SAMD21)
+        mp_obj_t tuple[7] = {
+            tuple[0] = mp_obj_new_str(name, strlen(name)),
+            tuple[1] = mp_obj_new_int(pin_af->eic),
+            tuple[2] = mp_obj_new_int(pin_af->adc0),
+            tuple[3] = mp_obj_new_int(pin_af->sercom1),
+            tuple[4] = mp_obj_new_int(pin_af->sercom2),
+            tuple[5] = mp_obj_new_int(pin_af->tcc1),
+            tuple[6] = mp_obj_new_int(pin_af->tcc2),
+        };
+        return mp_obj_new_tuple(7, tuple);
+        #elif defined(MCU_SAMD51)
+        mp_obj_t tuple[9] = {
+            tuple[0] = mp_obj_new_str(name, strlen(name)),
+            tuple[1] = mp_obj_new_int(pin_af->eic),
+            tuple[2] = mp_obj_new_int(pin_af->adc0),
+            tuple[3] = mp_obj_new_int(pin_af->adc1),
+            tuple[4] = mp_obj_new_int(pin_af->sercom1),
+            tuple[5] = mp_obj_new_int(pin_af->sercom2),
+            tuple[6] = mp_obj_new_int(pin_af->tc),
+            tuple[7] = mp_obj_new_int(pin_af->tcc1),
+            tuple[8] = mp_obj_new_int(pin_af->tcc2),
+        };
+        return mp_obj_new_tuple(9, tuple);
+        #endif
+    }
+    return mp_const_none;
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_1(samd_pininfo_obj, samd_pininfo);
+
 STATIC const mp_rom_map_elem_t samd_module_globals_table[] = {
     { MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR_samd) },
-    { MP_ROM_QSTR(MP_QSTR_Flash), MP_ROM_PTR(&samd_flash_type) },
+    { MP_ROM_QSTR(MP_QSTR_Flash),    MP_ROM_PTR(&samd_flash_type) },
+    { MP_ROM_QSTR(MP_QSTR_pininfo),  MP_ROM_PTR(&samd_pininfo_obj) },
 };
 STATIC MP_DEFINE_CONST_DICT(samd_module_globals, samd_module_globals_table);