digital IO write optimizations for 16bit parallel display types

- digitalWrite value increased to 16 bit width
- added IO device bit access functions
- removed PWM enable/disable from pinMode()

Author: stevstrong

STM32F4/cores/maple/io.h

@@ -121,7 +121,7 @@ void pinMode(uint8 pin, WiringPinMode mode);
  * @param value Either LOW (write a 0) or HIGH (write a 1).
  * @see pinMode()
  */
-void digitalWrite(uint8 pin, uint8 value);
+void digitalWrite(uint8 pin, uint16 value);
 
 /**
  * Read a digital value from a pin.  The pin must have its mode set to

STM32F4/cores/maple/libmaple/gpio.h

@@ -60,21 +60,31 @@ static inline afio_exti_port gpio_exti_port(const gpio_dev *dev) {
  * @param val If true, set the pin.  If false, reset the pin.
  */
 static inline void gpio_write_pin(uint8_t pin, uint16 val) {
+	uint16_t bit = BIT(pin&0x0F);
+	gpio_reg_map *regs = (PIN_MAP[pin].gpio_device)->regs;
     if (val) {
-        (PIN_MAP[pin].gpio_device)->regs->BSRRL = BIT(pin&0x0F);
+        regs->BSRRL = bit;
     } else {
-        (PIN_MAP[pin].gpio_device)->regs->BSRRH = BIT(pin&0x0F);
+        regs->BSRRH = bit;
     }
 }
 
 static inline void gpio_set_pin(uint8_t pin) {
 	(PIN_MAP[pin].gpio_device)->regs->BSRRL = BIT(pin&0x0F);
 }
 
+static inline void gpio_set_dev_bit(const gpio_dev * dev, uint8_t bit) {
+	dev->regs->BSRRL = BIT(bit);
+}
+
 static inline void gpio_clear_pin(uint8_t pin) {
 	(PIN_MAP[pin].gpio_device)->regs->BSRRH = BIT(pin&0x0F);
 }
 
+static inline void gpio_clear_dev_bit(const gpio_dev * dev, uint8_t bit) {
+	dev->regs->BSRRH = BIT(bit);
+}
+
 /**
  * Determine whether or not a GPIO pin is set.
  *

STM32F4/cores/maple/wirish_digital.cpp

@@ -73,14 +73,14 @@ void pinMode(uint8 pin, WiringPinMode mode) {
     }
 
     gpio_set_mode(pin, outputMode);
-
+/*
     if (PIN_MAP[pin].timer_device != NULL) {
-        /* Enable/disable timer channels if we're switching into or
-         * out of PWM. */
+        // Enable/disable timer channels if we're switching into or out of PWM.
         timer_set_mode(PIN_MAP[pin].timer_device,
                        PIN_MAP[pin].timer_channel,
                        pwm ? TIMER_PWM : TIMER_DISABLED);
     }
+*/
 }