Add open-drain GPIO support. (#15282)

* Add open-drain GPIO support.

* `qmk format-c`

* Wording.

* Remove port GPIO implementations as the only board that uses it has its own internal defs anyway. Will wait for first-class handling of ports in core before reimplementing.

4 files changed, 30 insertions, 47 deletions

diff --git a/docs/internals_gpio_control.md b/docs/internals_gpio_control.md
index ccd3f8c74d..e1f1515b71 100644
--- a/docs/internals_gpio_control.md
+++ b/docs/internals_gpio_control.md
@@ -6,17 +6,19 @@ QMK has a GPIO control abstraction layer which is microcontroller agnostic. This
 
 The following functions provide basic control of GPIOs and are found in `platforms/<platform>/gpio.h`.
 
-|Function                |Description                                       | Old AVR Examples                                | Old ChibiOS/ARM Examples                        |
-|------------------------|--------------------------------------------------|-------------------------------------------------|-------------------------------------------------|
-| `setPinInput(pin)`     | Set pin as input with high impedance (High-Z)    | `DDRB &= ~(1<<2)`                               | `palSetLineMode(pin, PAL_MODE_INPUT)`           |
-| `setPinInputHigh(pin)` | Set pin as input with builtin pull-up resistor   | `DDRB &= ~(1<<2); PORTB \|= (1<<2)`             | `palSetLineMode(pin, PAL_MODE_INPUT_PULLUP)`    |
-| `setPinInputLow(pin)`  | Set pin as input with builtin pull-down resistor | N/A (Not supported on AVR)                      | `palSetLineMode(pin, PAL_MODE_INPUT_PULLDOWN)`  |
-| `setPinOutput(pin)`    | Set pin as output                                | `DDRB \|= (1<<2)`                               | `palSetLineMode(pin, PAL_MODE_OUTPUT_PUSHPULL)` |
-| `writePinHigh(pin)`    | Set pin level as high, assuming it is an output  | `PORTB \|= (1<<2)`                              | `palSetLine(pin)`                               |
-| `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)`                            |
+| Function                     | Description                                         | Old AVR Examples                                | Old ChibiOS/ARM Examples                         |
+|------------------------------|-----------------------------------------------------|-------------------------------------------------|--------------------------------------------------|
+| `setPinInput(pin)`           | Set pin as input with high impedance (High-Z)       | `DDRB &= ~(1<<2)`                               | `palSetLineMode(pin, PAL_MODE_INPUT)`            |
+| `setPinInputHigh(pin)`       | Set pin as input with builtin pull-up resistor      | `DDRB &= ~(1<<2); PORTB \|= (1<<2)`             | `palSetLineMode(pin, PAL_MODE_INPUT_PULLUP)`     |
+| `setPinInputLow(pin)`        | Set pin as input with builtin pull-down resistor    | N/A (Not supported on AVR)                      | `palSetLineMode(pin, PAL_MODE_INPUT_PULLDOWN)`   |
+| `setPinOutput(pin)`          | Set pin as output (alias of `setPinOutputPushPull`) | `DDRB \|= (1<<2)`                               | `palSetLineMode(pin, PAL_MODE_OUTPUT_PUSHPULL)`  |
+| `setPinOutputPushPull(pin)`  | Set pin as output, push/pull mode                   | `DDRB \|= (1<<2)`                               | `palSetLineMode(pin, PAL_MODE_OUTPUT_PUSHPULL)`  |
+| `setPinOutputOpenDrain(pin)` | Set pin as output, open-drain mode                  | N/A (Not implemented on AVR)                    | `palSetLineMode(pin, PAL_MODE_OUTPUT_OPENDRAIN)` |
+| `writePinHigh(pin)`          | Set pin level as high, assuming it is an output     | `PORTB \|= (1<<2)`                              | `palSetLine(pin)`                                |
+| `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
 
diff --git a/platforms/arm_atsam/gpio.h b/platforms/arm_atsam/gpio.h
index 915ed0ef4f..a42aaff54d 100644
--- a/platforms/arm_atsam/gpio.h
+++ b/platforms/arm_atsam/gpio.h
@@ -22,9 +22,9 @@
 
 typedef uint8_t pin_t;
 
-#define SAMD_PORT(pin) ((pin & 0x20) >> 5)
-#define SAMD_PIN(pin) (pin & 0x1f)
-#define SAMD_PIN_MASK(pin) (1 << (pin & 0x1f))
+#define SAMD_PORT(pin) (((pin)&0x20) >> 5)
+#define SAMD_PIN(pin) ((pin)&0x1f)
+#define SAMD_PIN_MASK(pin) (1 << ((pin)&0x1f))
 
 #define setPinInput(pin)                                                                 \
     do {                                                                                 \
@@ -48,12 +48,16 @@ typedef uint8_t pin_t;
         PORT->Group[SAMD_PORT(pin)].PINCFG[SAMD_PIN(pin)].bit.PULLEN = 1;                  \
     } while (0)
 
-#define setPinOutput(pin)                                            \
+#define setPinOutputPushPull(pin)                                    \
     do {                                                             \
         PORT->Group[SAMD_PORT(pin)].DIRSET.reg = SAMD_PIN_MASK(pin); \
         PORT->Group[SAMD_PORT(pin)].OUTCLR.reg = SAMD_PIN_MASK(pin); \
     } while (0)
 
+#define setPinOutputOpenDrain(pin) _Static_assert(0, "arm_atsam platform does not implement an open-drain output")
+
+#define setPinOutput(pin) setPinOutputPushPull(pin)
+
 #define writePinHigh(pin)                                            \
     do {                                                             \
         PORT->Group[SAMD_PORT(pin)].OUTSET.reg = SAMD_PIN_MASK(pin); \
diff --git a/platforms/avr/gpio.h b/platforms/avr/gpio.h
index e9be68491d..95f15c28dc 100644
--- a/platforms/avr/gpio.h
+++ b/platforms/avr/gpio.h
@@ -25,7 +25,9 @@ typedef uint8_t pin_t;
 #define setPinInput(pin) (DDRx_ADDRESS(pin) &= ~_BV((pin)&0xF), PORTx_ADDRESS(pin) &= ~_BV((pin)&0xF))
 #define setPinInputHigh(pin) (DDRx_ADDRESS(pin) &= ~_BV((pin)&0xF), PORTx_ADDRESS(pin) |= _BV((pin)&0xF))
 #define setPinInputLow(pin) _Static_assert(0, "AVR processors cannot implement an input as pull low")
-#define setPinOutput(pin) (DDRx_ADDRESS(pin) |= _BV((pin)&0xF))
+#define setPinOutputPushPull(pin) (DDRx_ADDRESS(pin) |= _BV((pin)&0xF))
+#define setPinOutputOpenDrain(pin) _Static_assert(0, "AVR platform does not implement an open-drain output")
+#define setPinOutput(pin) setPinOutputPushPull(pin)
 
 #define writePinHigh(pin) (PORTx_ADDRESS(pin) |= _BV((pin)&0xF))
 #define writePinLow(pin) (PORTx_ADDRESS(pin) &= ~_BV((pin)&0xF))
@@ -34,16 +36,3 @@ typedef uint8_t pin_t;
 #define readPin(pin) ((bool)(PINx_ADDRESS(pin) & _BV((pin)&0xF)))
 
 #define togglePin(pin) (PORTx_ADDRESS(pin) ^= _BV((pin)&0xF))
-
-/* Operation of GPIO by port. */
-
-typedef uint8_t port_data_t;
-
-#define readPort(port) PINx_ADDRESS(port)
-
-#define setPortBitInput(port, bit) (DDRx_ADDRESS(port) &= ~_BV((bit)&0xF), PORTx_ADDRESS(port) &= ~_BV((bit)&0xF))
-#define setPortBitInputHigh(port, bit) (DDRx_ADDRESS(port) &= ~_BV((bit)&0xF), PORTx_ADDRESS(port) |= _BV((bit)&0xF))
-#define setPortBitOutput(port, bit) (DDRx_ADDRESS(port) |= _BV((bit)&0xF))
-
-#define writePortBitLow(port, bit) (PORTx_ADDRESS(port) &= ~_BV((bit)&0xF))
-#define writePortBitHigh(port, bit) (PORTx_ADDRESS(port) |= _BV((bit)&0xF))
diff --git a/platforms/chibios/gpio.h b/platforms/chibios/gpio.h
index 4d057f1cab..eb44a18f9c 100644
--- a/platforms/chibios/gpio.h
+++ b/platforms/chibios/gpio.h
@@ -22,10 +22,12 @@ typedef ioline_t pin_t;
 
 /* Operation of GPIO by pin. */
 
-#define setPinInput(pin) palSetLineMode(pin, PAL_MODE_INPUT)
-#define setPinInputHigh(pin) palSetLineMode(pin, PAL_MODE_INPUT_PULLUP)
-#define setPinInputLow(pin) palSetLineMode(pin, PAL_MODE_INPUT_PULLDOWN)
-#define setPinOutput(pin) palSetLineMode(pin, PAL_MODE_OUTPUT_PUSHPULL)
+#define setPinInput(pin) palSetLineMode((pin), PAL_MODE_INPUT)
+#define setPinInputHigh(pin) palSetLineMode((pin), PAL_MODE_INPUT_PULLUP)
+#define setPinInputLow(pin) palSetLineMode((pin), PAL_MODE_INPUT_PULLDOWN)
+#define setPinOutputPushPull(pin) palSetLineMode((pin), PAL_MODE_OUTPUT_PUSHPULL)
+#define setPinOutputOpenDrain(pin) palSetLineMode((pin), PAL_MODE_OUTPUT_OPENDRAIN)
+#define setPinOutput(pin) setPinOutputPushPull(pin)
 
 #define writePinHigh(pin) palSetLine(pin)
 #define writePinLow(pin) palClearLine(pin)
@@ -34,17 +36,3 @@ typedef ioline_t pin_t;
 #define readPin(pin) palReadLine(pin)
 
 #define togglePin(pin) palToggleLine(pin)
-
-/* Operation of GPIO by port. */
-
-typedef uint16_t port_data_t;
-
-#define readPort(pin) palReadPort(PAL_PORT(pin))
-
-#define setPortBitInput(pin, bit) palSetPadMode(PAL_PORT(pin), bit, PAL_MODE_INPUT)
-#define setPortBitInputHigh(pin, bit) palSetPadMode(PAL_PORT(pin), bit, PAL_MODE_INPUT_PULLUP)
-#define setPortBitInputLow(pin, bit) palSetPadMode(PAL_PORT(pin), bit, PAL_MODE_INPUT_PULLDOWN)
-#define setPortBitOutput(pin, bit) palSetPadMode(PAL_PORT(pin), bit, PAL_MODE_OUTPUT_PUSHPULL)
-
-#define writePortBitLow(pin, bit) palClearLine(PAL_LINE(PAL_PORT(pin), bit))
-#define writePortBitHigh(pin, bit) palSetLine(PAL_LINE(PAL_PORT(pin), bit))