pico w: Disentangle "TOTAL_GPIO_COUNT", it's complicated

You might wonder how this fixes a problem with PulseIn, when the
changes aren't to any of those files! PulseIn is implemented in terms of
StateMachine, which had some assumptions about the relation between
the index of a pin object in mcu_pin_global_dict_table and its "pin
number". This was true, until some pins were removed from the
microcontroller module on Pico W.

Closes: #7078

Author: jepler

ports/raspberrypi/common-hal/alarm/pin/PinAlarm.c

@@ -111,7 +111,7 @@ void alarm_pin_pinalarm_reset(void) {
     }
 
     // Reset pins and pin IRQs
-    for (size_t i = 0; i < TOTAL_GPIO_COUNT; i++) {
+    for (size_t i = 0; i < NUM_BANK0_GPIOS; i++) {
         if (alarm_reserved_pins & (1 << i)) {
             gpio_set_irq_enabled(i, GPIO_IRQ_ALL_EVENTS, false);
             reset_pin_number(i);

ports/raspberrypi/common-hal/microcontroller/Pin.c

@@ -46,32 +46,33 @@ void reset_pin_number_cyw(uint8_t pin_no) {
 STATIC uint32_t never_reset_pins;
 
 void reset_all_pins(void) {
-    for (size_t i = 0; i < TOTAL_GPIO_COUNT; i++) {
+    for (size_t i = 0; i < NUM_BANK0_GPIOS; i++) {
         if ((never_reset_pins & (1 << i)) != 0) {
             continue;
         }
         reset_pin_number(i);
     }
     #if CIRCUITPY_CYW43
     if (cyw_ever_init) {
-        for (size_t i = 0; i < 1; i++) {
-            cyw43_arch_gpio_put(i, 0);
-        }
+        // reset LED and SMPS_MODE to Low; don't touch VBUS_SENSE
+        // otherwise it is switched to output mode forever!
+        cyw43_arch_gpio_put(0, 0);
+        cyw43_arch_gpio_put(1, 0);
     }
     cyw_pin_claimed = 0;
     #endif
 }
 
 void never_reset_pin_number(uint8_t pin_number) {
-    if (pin_number >= TOTAL_GPIO_COUNT) {
+    if (pin_number >= NUM_BANK0_GPIOS) {
         return;
     }
 
     never_reset_pins |= 1 << pin_number;
 }
 
 void reset_pin_number(uint8_t pin_number) {
-    if (pin_number >= TOTAL_GPIO_COUNT) {
+    if (pin_number >= NUM_BANK0_GPIOS) {
         return;
     }
 
@@ -110,7 +111,7 @@ void claim_pin(const mcu_pin_obj_t *pin) {
 }
 
 bool pin_number_is_free(uint8_t pin_number) {
-    if (pin_number >= TOTAL_GPIO_COUNT) {
+    if (pin_number >= NUM_BANK0_GPIOS) {
         return false;
     }
 

ports/raspberrypi/common-hal/microcontroller/__init__.c

@@ -149,7 +149,7 @@ watchdog_watchdogtimer_obj_t common_hal_mcu_watchdogtimer_obj = {
 #endif
 
 // This maps MCU pin names to pin objects.
-const mp_rom_map_elem_t mcu_pin_global_dict_table[TOTAL_GPIO_COUNT] = {
+const mp_rom_map_elem_t mcu_pin_global_dict_table[] = {
     { MP_ROM_QSTR(MP_QSTR_GPIO0), MP_ROM_PTR(&pin_GPIO0) },
     { MP_ROM_QSTR(MP_QSTR_GPIO1), MP_ROM_PTR(&pin_GPIO1) },
     { MP_ROM_QSTR(MP_QSTR_GPIO2), MP_ROM_PTR(&pin_GPIO2) },
@@ -193,3 +193,13 @@ const mp_rom_map_elem_t mcu_pin_global_dict_table[TOTAL_GPIO_COUNT] = {
     #endif
 };
 MP_DEFINE_CONST_DICT(mcu_pin_globals, mcu_pin_global_dict_table);
+
+const mcu_pin_obj_t *mcu_get_pin_by_number(int number) {
+    for (size_t i = 0; i < MP_ARRAY_SIZE(mcu_pin_global_dict_table); i++) {
+        mcu_pin_obj_t *obj = MP_OBJ_TO_PTR(mcu_pin_global_dict_table[i].value);
+        if (obj->base.type == &mcu_pin_type && obj->number == number) {
+            return obj;
+        }
+    }
+    return NULL;
+}

ports/raspberrypi/common-hal/microcontroller/__init__.h

@@ -28,9 +28,8 @@
 #define MICROPY_INCLUDED_RASPBERRYPI_COMMON_HAL_MICROCONTROLLER___INIT___H
 
 #include "src/rp2040/hardware_regs/include/hardware/platform_defs.h"
+#include "peripherals/pins.h"
 
-#define TOTAL_GPIO_COUNT NUM_BANK0_GPIOS
-
-extern const mp_rom_map_elem_t mcu_pin_global_dict_table[TOTAL_GPIO_COUNT];
+const mcu_pin_obj_t *mcu_get_pin_by_number(int);
 
 #endif // MICROPY_INCLUDED_RASPBERRYPI_COMMON_HAL_MICROCONTROLLER___INIT___H

ports/raspberrypi/common-hal/rp2pio/StateMachine.c

@@ -48,7 +48,7 @@
 #define NO_DMA_CHANNEL (-1)
 
 // Count how many state machines are using each pin.
-STATIC uint8_t _pin_reference_count[TOTAL_GPIO_COUNT];
+STATIC uint8_t _pin_reference_count[NUM_BANK0_GPIOS];
 STATIC uint32_t _current_program_id[NUM_PIOS][NUM_PIO_STATE_MACHINES];
 STATIC uint8_t _current_program_offset[NUM_PIOS][NUM_PIO_STATE_MACHINES];
 STATIC uint8_t _current_program_len[NUM_PIOS][NUM_PIO_STATE_MACHINES];
@@ -71,7 +71,7 @@ STATIC void *_interrupt_arg[NUM_PIOS][NUM_PIO_STATE_MACHINES];
 STATIC void rp2pio_statemachine_interrupt_handler(void);
 
 static void rp2pio_statemachine_set_pull(uint32_t pull_pin_up, uint32_t pull_pin_down, uint32_t pins_we_use) {
-    for (size_t i = 0; i < TOTAL_GPIO_COUNT; i++) {
+    for (size_t i = 0; i < NUM_BANK0_GPIOS; i++) {
         bool used = pins_we_use & (1 << i);
         if (used) {
             bool pull_up = pull_pin_up & (1 << i);
@@ -120,7 +120,7 @@ STATIC void _reset_statemachine(PIO pio, uint8_t sm, bool leave_pins) {
     }
 
     uint32_t pins = _current_sm_pins[pio_index][sm];
-    for (size_t pin_number = 0; pin_number < TOTAL_GPIO_COUNT; pin_number++) {
+    for (size_t pin_number = 0; pin_number < NUM_BANK0_GPIOS; pin_number++) {
         if ((pins & (1 << pin_number)) == 0) {
             continue;
         }
@@ -161,10 +161,14 @@ STATIC uint32_t _check_pins_free(const mcu_pin_obj_t *first_pin, uint8_t pin_cou
     if (first_pin != NULL) {
         for (size_t i = 0; i < pin_count; i++) {
             uint8_t pin_number = first_pin->number + i;
-            if (pin_number >= TOTAL_GPIO_COUNT) {
+            if (pin_number >= NUM_BANK0_GPIOS) {
                 mp_raise_ValueError(translate("Pin count too large"));
             }
-            const mcu_pin_obj_t *pin = mcu_pin_global_dict_table[pin_number].value;
+            const mcu_pin_obj_t *pin = mcu_get_pin_by_number(pin_number);
+            if (!pin) {
+                mp_raise_ValueError_varg(translate("%q in use"), MP_QSTR_Pin);
+            }
+
             if (exclusive_pin_use || _pin_reference_count[pin_number] == 0) {
                 assert_pin_free(pin);
             }
@@ -269,12 +273,15 @@ bool rp2pio_statemachine_construct(rp2pio_statemachine_obj_t *self,
     self->pull_pin_up = pull_pin_up;
     self->pull_pin_down = pull_pin_down;
 
-    for (size_t pin_number = 0; pin_number < TOTAL_GPIO_COUNT; pin_number++) {
+    for (size_t pin_number = 0; pin_number < NUM_BANK0_GPIOS; pin_number++) {
         if ((pins_we_use & (1 << pin_number)) == 0) {
             continue;
         }
+        const mcu_pin_obj_t *pin = mcu_get_pin_by_number(pin_number);
+        if (!pin) {
+            return false;
+        }
         _pin_reference_count[pin_number]++;
-        const mcu_pin_obj_t *pin = mcu_pin_global_dict_table[pin_number].value;
         // Also claim the pin at the top level when we're the first to grab it.
         if (_pin_reference_count[pin_number] == 1) {
             if (claim_pins) {