Fix IPod 3G USB Recognition Problem

Allow IPod 3rd generation to recognize when USB is connected and reboot into disk mode.
This problem is listed at the bottom of the Ipod status page https://www.rockbox.org/wiki/IpodStatus

Change-Id: I8f32afd065d3a91cddc56fe63454bd082bfa29b9

2 files changed, 12 insertions, 5 deletions

diff --git a/docs/CREDITS b/docs/CREDITS
index 012b31c72b..a1041f4952 100644
--- a/docs/CREDITS
+++ b/docs/CREDITS
@@ -696,6 +696,7 @@ Adrián Tinoco
 Boris Kovačević
 Stéphane Moutard-Martin
 Rune Pade
+Michael Rey
 
 The libmad team
 The wavpack team
diff --git a/firmware/target/arm/pp/usb-fw-pp5002.c b/firmware/target/arm/pp/usb-fw-pp5002.c
index d296b05b2f..d0fbbd6e48 100644
--- a/firmware/target/arm/pp/usb-fw-pp5002.c
+++ b/firmware/target/arm/pp/usb-fw-pp5002.c
@@ -28,12 +28,14 @@
 
 void usb_pin_init(void)
 {
-    /* TODO: add USB init for iPod 3rd gen */
-
-#if defined(IPOD_1G2G) || defined(IPOD_3G)
+#if defined(IPOD_1G2G)
     /* GPIO C bit 7 is firewire detect */
     GPIOC_ENABLE    |=  0x80;
     GPIOC_OUTPUT_EN &= ~0x80;
+#elif defined(IPOD_3G)
+    /* GPIO D bit 4 is USB detect */
+    GPIOD_ENABLE    |=  0x10;
+    GPIOD_OUTPUT_EN &= ~0x10;
 #endif
 }
 
@@ -62,13 +64,17 @@ void usb_enable(bool on)
 
 int usb_detect(void)
 {
-#if defined(IPOD_1G2G) || defined(IPOD_3G)
+#if defined(IPOD_1G2G)
     /* GPIO C bit 7 is firewire detect */
     if (!(GPIOC_INPUT_VAL & 0x80))
         return USB_INSERTED;
 #endif
 
-    /* TODO: add USB detection for iPod 3rd gen */
+#if defined(IPOD_3G)
+    /* GPIO D bit 4 is USB detect */
+    if (GPIOD_INPUT_VAL & 0x10)
+        return USB_INSERTED;
+#endif
 
     return USB_EXTRACTED;
 }