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Add open-drain GPIO support. #15282

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Dec 27, 2021
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Merged

Add open-drain GPIO support. #15282

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0c6a4c8
Add open-drain GPIO support.
tzarc Nov 23, 2021
8defc7b
`qmk format-c`
tzarc Nov 23, 2021
2aa121b
Wording.
tzarc Nov 23, 2021
bc81f52
Merge remote-tracking branch 'upstream/develop' into open-drain-outputs
tzarc Nov 28, 2021
cb6e057
Merge remote-tracking branch 'upstream/develop' into open-drain-outputs
tzarc Dec 9, 2021
d33a2d1
Remove port GPIO implementations as the only board that uses it has i…
tzarc Dec 9, 2021
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24 changes: 13 additions & 11 deletions docs/internals_gpio_control.md
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Expand Up @@ -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

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12 changes: 8 additions & 4 deletions platforms/arm_atsam/gpio.h
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Expand Up @@ -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 { \
Expand All @@ -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); \
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8 changes: 6 additions & 2 deletions platforms/avr/gpio.h
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Expand Up @@ -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")
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Technically it is possible to implement an open-drain output on AVR — set the PORTx bit to 0, then write the inverted output value to the DDRx bit. The problem is that it requires either some conditional code in the writePin() implementation, or a separate set of macros like writeOpenDrainPin(), writeOpenDrainPinHigh(), writeOpenDrainPinLow() (with bad consequences if you use a wrong kind of macro for the chosen pin mode).

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Yep, but nobody has asked for it, and nobody's using it. Figured it'd be a problem for another day.

#define setPinOutput(pin) setPinOutputPushPull(pin)

#define writePinHigh(pin) (PORTx_ADDRESS(pin) |= _BV((pin)&0xF))
#define writePinLow(pin) (PORTx_ADDRESS(pin) &= ~_BV((pin)&0xF))
Expand All @@ -43,7 +45,9 @@ typedef uint8_t port_data_t;

#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 setPortBitOutputPushPull(port, bit) (DDRx_ADDRESS(port) |= _BV((bit)&0xF))
#define setPortBitOutputOpenDrain(port, bit) _Static_assert(0, "AVR platform does not implement an open-drain output")
#define setPortBitOutput(port, bit) setPortBitOutputPushPull((port), (bit))

#define writePortBitLow(port, bit) (PORTx_ADDRESS(port) &= ~_BV((bit)&0xF))
#define writePortBitHigh(port, bit) (PORTx_ADDRESS(port) |= _BV((bit)&0xF))
22 changes: 12 additions & 10 deletions platforms/chibios/gpio.h
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Expand Up @@ -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)
Expand All @@ -41,10 +43,10 @@ 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 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)
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Hmm, looks like the implementation of setPortBitOutputPushPull() and setPortBitOutputOpenDrain() is missing here?

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As discussed on Discord, given that it's not in use anywhere but one keyboard, and it has its own implementation of the port-based GPIO functions, the port-related operations have been removed for the time being until we work out a proper solution for them.


#define writePortBitLow(pin, bit) palClearLine(PAL_LINE(PAL_PORT(pin), bit))
#define writePortBitHigh(pin, bit) palSetLine(PAL_LINE(PAL_PORT(pin), bit))
#define writePortBitLow(pin, bit) palClearLine(PAL_LINE(PAL_PORT(pin), (bit)))
#define writePortBitHigh(pin, bit) palSetLine(PAL_LINE(PAL_PORT(pin), (bit)))