Created PWM object linking pin name, channel and function (alt0, alt1, ...)

Author: nponcetaexp

Gpio.cpp

@@ -61,7 +61,7 @@ void Gpio::setup_pin(GpioPinIO pin) {
 	std::uint8_t fun_static = static_cast<std::uint8_t>(pin.function);
 
 	bcm2835_gpio_fsel(pin_static, fun_static);
-	LOG("setup pin:%d function:%d", pin_static, fun_static);
+	LOG("setup io pin:%d function:%d", pin_static, fun_static);
 
 	// if specified set PullUp resistor
 	if (pin.pullUp != GpioPullUp::none) {
@@ -72,38 +72,24 @@ void Gpio::setup_pin(GpioPinIO pin) {
 	}
 }
 
-void Gpio::setup_pin(GpioPwm pin) {
-	std::uint8_t channel = get_pwm_channel(pin);
+void Gpio::setup_pin(GpioPwm pwm) {
+	GpioPwmItem *item = pwm.item;
+	if (item != NULL) {
+		std::uint8_t pin = item->name;
+		std::uint8_t channel = item->channel;
+		std::uint8_t function = item->function;
 
-	if (channel >= 0 && pin.mode != GpioPwmMode::unknown) {
-		bcm2835_pwm_set_mode(channel, static_cast<std::uint8_t>(pin.mode), 1 /* 1=enable */);
-	}
-
-	if (channel >= 0 && pin.range > 0) {
-		bcm2835_pwm_set_range(channel, pin.range);
-	}
-}
+		bcm2835_gpio_fsel(pin, function);
+		LOG("setup pwm pin:%d function:%d", pin, function);
 
-std::uint8_t Gpio::get_pwm_channel(GpioPwm pin) {
-	std::uint8_t channel = -1;
-
-	switch(pin.name) {
-		case GpioPwmName::pwm1_gpio19:
-		case GpioPwmName::pwm1_gpio13:
-			channel = 1;
-			break;
-
-		case GpioPwmName::pwm0_gpio18:
-		case GpioPwmName::pwm0_gpio12:
-			channel = 0;
-			break;
+		if (channel >= 0 && pwm.mode != GpioPwmMode::unknown) {
+			bcm2835_pwm_set_mode(channel, static_cast<std::uint8_t>(pwm.mode), 1 /* 1=enable */);
+		}
 
-		default:
-			channel = -1;
-			break;
+		if (channel >= 0 && pwm.range > 0) {
+			bcm2835_pwm_set_range(channel, pwm.range);
+		}
 	}
-
-	return channel;
 }
 
 void Gpio::read(std::list<GpioPinIO*> pin_list) {
@@ -117,10 +103,13 @@ void Gpio::read(std::list<GpioPinIO*> pin_list) {
 
 void Gpio::read(std::list<GpioPwm*> pin_list) {
 	for (GpioPwm *pin : pin_list) {
-		std::uint8_t pin_static = static_cast<std::uint8_t>(pin->name);
-
-		pin->value = bcm2835_gpio_lev(pin_static);
-		LOG("read PWM pin:%d value:%d", pin_static, pin->value);
+		GpioPwmItem *item = pin->item;
+		if (item != NULL) {
+			pin->value = bcm2835_gpio_lev(item->name);
+			LOG("read PWM pin:%d value:%d", item->name, pin->value);
+		} else {
+			LOG("read PWM error: pin not initialized");
+		}
 	}
 }
 
@@ -151,11 +140,10 @@ void Gpio::write(GpioPinIO* pin, bool val) {
 }
 
 void Gpio::write(GpioPwm* pin, std::uint32_t val) {
-	std::uint8_t channel = get_pwm_channel(*pin);
-
-	if (channel >= 0) {
-		bcm2835_pwm_set_data(channel, val);
-		LOG("write PWM channel:%d value:%d", channel, val);
+	GpioPwmItem *item = pin->item;
+	if (item != NULL) {
+		bcm2835_pwm_set_data(item->channel, val);
+		LOG("write PWM channel:%d value:%d", item->channel, val);
 	} else {
 		std::cerr << "write PWM channel not found" << std::endl;
 	}

Gpio.h

@@ -32,7 +32,7 @@ using namespace std;
 #define BCM2835_INIT_SPI_ERROR  -2
 #define BCM2835_CLOSE_ERROR     -3
 
-// Pin names
+// GPIO pin names
 enum class GpioPinName: std::uint8_t {
   unknown = 0xff,
   gpio27 = RPI_V2_GPIO_P1_13,
@@ -45,26 +45,59 @@ enum class GpioPinName: std::uint8_t {
   gpio4 = RPI_V2_GPIO_P1_07
 };
 
-// Pin names
-enum class GpioPwmName: std::uint8_t {
-  unknown = 0xff,
-  pwm1_gpio19 = RPI_V2_GPIO_P1_35,   /*!< Can be PWM channel 1 in ALT FUN 5 */
-  pwm0_gpio18 = RPI_V2_GPIO_P1_12,   /*!< Can be PWM channel 0 in ALT FUN 5 */
-  pwm1_gpio13 = RPI_V2_GPIO_P1_33,   /*!< Can be PWM channel 1 in ALT FUN 0 */
-  pwm0_gpio12 = RPI_V2_GPIO_P1_32,   /*!< Can be PWM channel 0 in ALT FUN 0 */
+// PWM pin names
+enum class GpioPwmName {
+  pwm1_gpio19,
+  pwm0_gpio18,
+  pwm1_gpio13,
+  pwm0_gpio12
+};
+
+class GpioPwmItem {
+  private:
+    GpioPwmItem (
+      std::uint8_t name,
+      std::uint8_t function,
+      std::uint8_t channel
+    ) {
+      this->name = name;
+      this->function = function;
+      this->channel = channel;
+    }
+
+  public:
+    std::uint8_t name;
+    std::uint8_t function;
+    std::uint8_t channel;
+
+    static GpioPwmItem* create(GpioPwmName pwm_name) {
+      GpioPwmItem *item = NULL;
+      switch(pwm_name) {
+        case GpioPwmName::pwm1_gpio19:
+          item = new GpioPwmItem(RPI_V2_GPIO_P1_35, BCM2835_GPIO_FSEL_ALT5, 1);
+        break;
+
+        case GpioPwmName::pwm0_gpio18:
+        item = new GpioPwmItem(RPI_V2_GPIO_P1_12, BCM2835_GPIO_FSEL_ALT5, 0);
+        break;
+
+        case GpioPwmName::pwm1_gpio13:
+        item = new GpioPwmItem(RPI_V2_GPIO_P1_33, BCM2835_GPIO_FSEL_ALT0, 1);
+        break;
+
+        case GpioPwmName::pwm0_gpio12:
+        item = new GpioPwmItem(RPI_V2_GPIO_P1_32, BCM2835_GPIO_FSEL_ALT0, 0);
+        break;
+      }
+      return item;
+    }
 };
 
 // Functions
 enum class GpioFunction: std::uint8_t {
   unknown = 0xff,
   input = BCM2835_GPIO_FSEL_INPT,
-  output = BCM2835_GPIO_FSEL_OUTP,
-  alt0 = BCM2835_GPIO_FSEL_ALT0,
-  alt1 = BCM2835_GPIO_FSEL_ALT1,
-  alt2 = BCM2835_GPIO_FSEL_ALT2,
-  alt3 = BCM2835_GPIO_FSEL_ALT3,
-  alt4 = BCM2835_GPIO_FSEL_ALT4,
-  alt5 = BCM2835_GPIO_FSEL_ALT5
+  output = BCM2835_GPIO_FSEL_OUTP
 };
 
 // Pull up resistor
@@ -112,16 +145,36 @@ class GpioPinIO : GpioPinConfigCommon
     bool value            = false;
     GpioFunction function = GpioFunction::unknown;
     GpioPullUp pullUp     = GpioPullUp::none;
+
+    GpioPinIO (
+      GpioPinName name,
+      GpioFunction function = GpioFunction::unknown,
+      GpioPullUp pullUp     = GpioPullUp::none
+    ) {
+      this->name = name;
+      this->function = function;
+      this->pullUp = pullUp;
+    }
 };
 
 // PWM
 class GpioPwm : GpioPinConfigCommon
 {
   public:
-    GpioPwmName name    = GpioPwmName::unknown;
+    GpioPwmItem *item   = NULL;
     std::uint32_t value = 0;
     GpioPwmMode mode    = GpioPwmMode::unknown;
     std::uint32_t range = 0xff;
+
+    GpioPwm (
+      GpioPwmItem *item,
+      std::uint32_t range = 0xff,
+      GpioPwmMode mode    = GpioPwmMode::unknown
+    ) {
+      this->item = item;
+      this->range = range;
+      this->mode = mode;
+    }
 };
 
 class Gpio {
@@ -145,7 +198,6 @@ class Gpio {
     int init_gpio();
     int init_spi();
     int close_gpio();
-    std::uint8_t get_pwm_channel(GpioPwm pin);
 };
 
 #endif