From 08ddabf7a5c5607626c467c70d63ee4bee4ebe0c Mon Sep 17 00:00:00 2001
From: Kristian Sloth Lauszus <lauszus@gmail.com>
Date: Thu, 19 Mar 2015 20:09:27 +0100
Subject: [PATCH] Use much faster GPIO pin 2 and 3 on Intel Galileo & Intel
 Galileo 2

---
 README.md |  5 +++--
 UsbCore.h |  4 +++-
 avrpins.h | 21 +++++++++++++++------
 3 files changed, 21 insertions(+), 9 deletions(-)

diff --git a/README.md b/README.md
index 4df40f13..53b55204 100644
--- a/README.md
+++ b/README.md
@@ -92,8 +92,9 @@ By default serial debugging is disabled. To turn it on simply change ```ENABLE_U
 Currently the following boards are supported by the library:
 
 * All official Arduino AVR boards (Uno, Duemilanove, Mega, Mega 2560, Mega ADK, Leonardo etc.)
-* Arduino Due and Arduino Galileo
-    * If you are using the Arduino Due or Galileo, then you must include the Arduino SPI library like so: ```#include <SPI.h>``` in your .ino file.
+* Arduino Due, Intel Galileo and Intel Galileo 2
+    * If you are using the Arduino Due, Intel Galileo or Intel Galileo 2, then you must include the Arduino SPI library like so: ```#include <SPI.h>``` in your .ino file.
+    * Note that both the Intel Galileo and Intel Galileo 2 use pin 2 and 3 as INT and SS pin respectively by default, so some modifications to the shield are needed. See the "Interface modifications" section in the [hardware manual](https://www.circuitsathome.com/usb-host-shield-hardware-manual) for more information.
 * Teensy (Teensy++ 1.0, Teensy 2.0, Teensy++ 2.0, and Teensy 3.x)
     * Note if you are using the Teensy 3.x you should download this SPI library as well: <https://github.com/xxxajk/spi4teensy3>. You should then add ```#include <spi4teensy3.h>``` to your .ino file.
 * Balanduino
diff --git a/UsbCore.h b/UsbCore.h
index d76f1858..d8356d04 100644
--- a/UsbCore.h
+++ b/UsbCore.h
@@ -37,8 +37,10 @@ typedef MAX3421e<P9, P8> MAX3421E; // Teensy++ 1.0 and 2.0
 typedef MAX3421e<P53, P54> MAX3421E; // Arduino Mega ADK
 #elif defined(ARDUINO_AVR_BALANDUINO)
 typedef MAX3421e<P20, P19> MAX3421E; // Balanduino
+#elif defined(__ARDUINO_X86__)
+typedef MAX3421e<P3, P2> MAX3421E; // The Intel Galileo and Intel Galileo 2 both support much faster read and write speed at pin 2 and 3
 #else
-typedef MAX3421e<P10, P9> MAX3421E; // Official Arduinos (UNO, Duemilanove, Mega, 2560, Leonardo, Due etc.), Intel Galileo or Teensy 2.0 and 3.0
+typedef MAX3421e<P10, P9> MAX3421E; // Official Arduinos (UNO, Duemilanove, Mega, 2560, Leonardo, Due etc.) or Teensy 2.0 and 3.0
 #endif
 
 /* Common setup data constant combinations  */
diff --git a/avrpins.h b/avrpins.h
index 7acf492a..3f02d5c4 100644
--- a/avrpins.h
+++ b/avrpins.h
@@ -1015,30 +1015,39 @@ MAKE_PIN(P24, Pin_nRF51822_to_Arduino(D24));
 
 #endif
 
-#elif defined(__ARDUINO_X86__) // Intel Galileo
+#elif defined(__ARDUINO_X86__) // Intel Galileo and Intel Galileo 2
 
 #include <avr/pgmspace.h>
 
 // Pointers are 32 bits on x86
 #define pgm_read_pointer(p) pgm_read_dword(p)
 
+// Pin 2 and 3 support a higher rate, so it is recommended to use one of these as the SS pin.
+// I know Intel Galileo 2 support higher rate at some other pins as well, but 2 and 3 are only
+// available on the original Intel Galileo.
 #define MAKE_PIN(className, pin) \
 class className { \
 public: \
   static void Set() { \
-    digitalWrite(pin, HIGH); \
+    fastDigitalWrite(pin, HIGH); \
   } \
   static void Clear() { \
-    digitalWrite(pin, LOW); \
+    fastDigitalWrite(pin, LOW); \
   } \
   static void SetDirRead() { \
-    pinMode(pin, INPUT); \
+    if (pinToFastPin(pin)) \
+      pinMode(pin, INPUT_FAST); \
+    else \
+      pinMode(pin, INPUT); \
   } \
   static void SetDirWrite() { \
-    pinMode(pin, OUTPUT); \
+    if (pinToFastPin(pin)) \
+      pinMode(pin, OUTPUT_FAST); \
+    else \
+      pinMode(pin, OUTPUT); \
   } \
   static uint8_t IsSet() { \
-    return digitalRead(pin); \
+    return fastDigitalRead(pin); \
   } \
 };