cpu/esp32: GPIO macro cleanup in periph_cpu.h

The default macros GPIO_PIN and GPIO_UNDEF do not have to be overridden. The GPIO_PIN macro definition was even wrong for 40 GPIOs without splitting into ports, even if that did not lead to erroneous behavior.

cpu/esp32/esp-eth/esp_eth_netdev.c

@@ -109,11 +109,14 @@ static esp_err_t IRAM_ATTR _eth_input_callback(void *buffer, uint16_t len, void
     return ESP_OK;
 }
 
-#if EMAC_PHY_POWER_PIN != GPIO_UNDEF
 static void _esp_eth_phy_power_enable_gpio(bool enable)
 {
     assert(EMAC_ETHERNET_PHY_CONFIG.phy_power_enable);
 
+    if (EMAC_PHY_POWER_PIN == GPIO_UNDEF) {
+        return;
+    }
+
     if (!enable) {
         EMAC_ETHERNET_PHY_CONFIG.phy_power_enable(false);
     }
@@ -127,7 +130,6 @@ static void _esp_eth_phy_power_enable_gpio(bool enable)
         EMAC_ETHERNET_PHY_CONFIG.phy_power_enable(true);
     }
 }
-#endif
 
 static int _esp_eth_init(netdev_t *netdev)
 {
@@ -146,13 +148,13 @@ static int _esp_eth_init(netdev_t *netdev)
     config.gpio_config = _eth_gpio_config_rmii;
     config.tcpip_input = _eth_input_callback;
 
-    #if EMAC_PHY_POWER_PIN != GPIO_UNDEF
     /*
      * Replace the default 'power enable' function with an example-specific
      * one that toggles a power GPIO.
      */
-    config.phy_power_enable = phy_device_power_enable_via_gpio;
-    #endif
+    if (EMAC_PHY_POWER_PIN != GPIO_UNDEF) {
+        config.phy_power_enable = _esp_eth_phy_power_enable_gpio;
+    }
 
     /* initialize EMAC with config */
     if (ret == ESP_OK && (ret = esp_eth_init(&config)) != ESP_OK) {

cpu/esp32/include/periph_cpu.h

@@ -46,16 +46,6 @@ extern "C" {
 #define PORT_GPIO 0       /**< port GPIO */
 /** @} */
 
-/**
- * @brief   Definition of a fitting UNDEF value
- */
-#define GPIO_UNDEF (0xff)
-
-/**
- * @brief   Define CPU specific GPIO pin generator macro
- */
-#define GPIO_PIN(x, y)  ((x << 4) | y)
-
 /**
  * @brief   Define CPU specific number of GPIO pins
  * @{