add 'togglePin' convenience function (#8734)

* add 'togglePin' conveniance function

for AVR and chibios

* drop outmost parantheses

Co-Authored-By: Konstantin Đorđević <vomindoraan@gmail.com>

* toggle pin on avrs

toggle a pin configured as output by writing the corresponding bit to the PIN register

Co-Authored-By: Takeshi ISHII <2170248+mtei@users.noreply.github.com>

* togglepin: add documentation for newly added function

* Update docs/internals_gpio_control.md

Co-Authored-By: Konstantin Đorđević <vomindoraan@gmail.com>

* on AVR: use PORTD to toggle the output

... since not all MCUs support toggling through writing to PIN

Co-Authored-By: Ryan <fauxpark@gmail.com>

Co-authored-by: Johannes <you@example.com>
Co-authored-by: Konstantin Đorđević <vomindoraan@gmail.com>
Co-authored-by: Takeshi ISHII <2170248+mtei@users.noreply.github.com>
Co-authored-by: Ryan <fauxpark@gmail.com>

docs/internals_gpio_control.md

@@ -16,6 +16,7 @@ The following functions can provide basic control of GPIOs and are found in `qua
 | `writePinLow(pin)`     | Set pin level as low, assuming it is an output   | `PORTB &= ~(1<<2)`                              | `palClearLine(pin)`                             |
 | `writePin(pin, level)` | Set pin level, assuming it is an output          | `(level) ? PORTB \|= (1<<2) : PORTB &= ~(1<<2)` | `(level) ? palSetLine(pin) : palClearLine(pin)` |
 | `readPin(pin)`         | Returns the level of the pin                     | `_SFR_IO8(pin >> 4) & _BV(pin & 0xF)`           | `palReadLine(pin)`                              |
+| `togglePin(pin)`       | Invert pin level, assuming it is an output       | `PORTB ^= (1<<2)`                               | `palToggleLine(pin)`                            |
 
 ## Advanced Settings :id=advanced-settings
 

quantum/quantum.h

@@ -197,6 +197,8 @@ typedef uint8_t pin_t;
 
 #    define readPin(pin) ((bool)(PINx_ADDRESS(pin) & _BV((pin)&0xF)))
 
+#    define togglePin(pin)  (PORTx_ADDRESS(pin) ^= _BV((pin)&0xF))
+
 #elif defined(PROTOCOL_CHIBIOS)
 typedef ioline_t pin_t;
 
@@ -210,6 +212,8 @@ typedef ioline_t pin_t;
 #    define writePin(pin, level) ((level) ? writePinHigh(pin) : writePinLow(pin))
 
 #    define readPin(pin) palReadLine(pin)
+
+#    define togglePin(pin) palToggleLine(pin)
 #endif
 
 #define SEND_STRING(string) send_string_P(PSTR(string))