Allow users to disable i2c bus and use simple buttons.

More info: https://github.com/BlueSCSI/BlueSCSI-v2/wiki/Buttons

lib/BlueSCSI_platform_RP2MCU/BlueSCSI_platform.cpp

@@ -1103,6 +1103,15 @@ void platform_reset_mcu()
 {
     watchdog_reboot(0, 0, 2000);
 }
+bool platform_has_i2c() {
+    return is2023a;
+}
+bool disable_i2c = false;
+void platform_disable_i2c() {
+    gpio_conf(GPIO_I2C_SCL, GPIO_FUNC_SIO, true, false, false, false, false);
+    gpio_conf(GPIO_I2C_SDA, GPIO_FUNC_SIO, true, false, false, false, false);
+    disable_i2c = true;
+}
 
 uint8_t platform_get_buttons()
 {
@@ -1117,9 +1126,13 @@ uint8_t platform_get_buttons()
     // if (!gpio_get(GPIO_I2C_SCL)) buttons |= 2;
 #endif // defined(ENABLE_AUDIO_OUTPUT_SPDIF)
 
-    if (!is2023a) {
+    if (!is2023a) { // Pre-2023a boards have buttons on GPIO pins labeled SW1 and SW2
         if (!gpio_get(BUTTON_SW1_PRE202309a)) buttons |= 1;
         if (!gpio_get(BUTTON_SW2_PRE202309a)) buttons |= 2;
+    } else if (disable_i2c) // User wants simple buttons instead of an i2c panel
+    {
+        if (!gpio_get(GPIO_I2C_SCL)) buttons |= 1;
+        if (!gpio_get(GPIO_I2C_SDA)) buttons |= 2;
     }
 
     static uint8_t debounced_state = 0;
@@ -1141,7 +1154,7 @@ uint8_t platform_get_buttons()
 bool platform_has_phy_eject_button()
 {
     // 2023a and later boards have i2c buttons
-    return !is2023a;
+    return !is2023a || (is2023a && disable_i2c);
 }
 
 /************************************/

lib/BlueSCSI_platform_RP2MCU/BlueSCSI_platform.h

@@ -181,7 +181,7 @@ extern const uint16_t g_scsi_parity_check_lookup[512];
 
 // Returns true if the board has a physical eject button 
 bool platform_has_phy_eject_button();
-
+void platform_disable_i2c();
 #ifdef __cplusplus
 }
 

src/BlueSCSI.cpp

@@ -1178,6 +1178,10 @@ static void bluescsi_setup_sd_card(bool wait_for_card = true)
   if (!platform_is_initiator_mode_enabled())
 #endif
   {
+    if (platform_supports_initiator_mode() && ini_getbool("SCSI", "DisableI2C", false, CONFIGFILE)) {
+      logmsg("Disabling I2C bus for simple buttons instead.");
+      platform_disable_i2c();
+    }
     init_eject_button();
   }