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Software/Python/grove_i2c_touch/Platform.py

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+# Copyright (c) 2014 Adafruit Industries
+# Author: Tony DiCola
+
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+
+# The above copyright notice and this permission notice shall be included in all
+# copies or substantial portions of the Software.
+
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+import platform
+import re
+
+# Platform identification constants.
+UNKNOWN          = 0
+RASPBERRY_PI     = 1
+BEAGLEBONE_BLACK = 2
+MINNOWBOARD      = 3
+
+def platform_detect():
+    """Detect if running on the Raspberry Pi or Beaglebone Black and return the
+    platform type.  Will return RASPBERRY_PI, BEAGLEBONE_BLACK, or UNKNOWN."""
+    # Handle Raspberry Pi
+    pi = pi_version()
+    if pi is not None:
+        return RASPBERRY_PI
+
+    # Handle Beaglebone Black
+    # TODO: Check the Beaglebone Black /proc/cpuinfo value instead of reading
+    # the platform.
+    plat = platform.platform()
+    if plat.lower().find('armv7l-with-debian') > -1:
+        return BEAGLEBONE_BLACK
+    elif plat.lower().find('armv7l-with-ubuntu') > -1:
+        return BEAGLEBONE_BLACK
+    elif plat.lower().find('armv7l-with-glibc2.4') > -1:
+        return BEAGLEBONE_BLACK
+        
+    # Handle Minnowboard
+    # Assumption is that mraa is installed
+    try: 
+        import mraa 
+        if mraa.getPlatformName()=='MinnowBoard MAX':
+            return MINNOWBOARD
+    except ImportError:
+        pass
+    
+    # Couldn't figure out the platform, just return unknown.
+    return UNKNOWN
+
+
+def pi_revision():
+    """Detect the revision number of a Raspberry Pi, useful for changing
+    functionality like default I2C bus based on revision."""
+    # Revision list available at: http://elinux.org/RPi_HardwareHistory#Board_Revision_History
+    with open('/proc/cpuinfo', 'r') as infile:
+        for line in infile:
+            # Match a line of the form "Revision : 0002" while ignoring extra
+            # info in front of the revsion (like 1000 when the Pi was over-volted).
+            match = re.match('Revision\s+:\s+.*(\w{4})$', line, flags=re.IGNORECASE)
+            if match and match.group(1) in ['0000', '0002', '0003']:
+                # Return revision 1 if revision ends with 0000, 0002 or 0003.
+                return 1
+            elif match:
+                # Assume revision 2 if revision ends with any other 4 chars.
+                return 2
+        # Couldn't find the revision, throw an exception.
+        raise RuntimeError('Could not determine Raspberry Pi revision.')
+
+
+def pi_version():
+    """Detect the version of the Raspberry Pi.  Returns either 1, 2 or
+    None depending on if it's a Raspberry Pi 1 (model A, B, A+, B+),
+    Raspberry Pi 2 (model B+), or not a Raspberry Pi.
+    """
+    # Check /proc/cpuinfo for the Hardware field value.
+    # 2708 is pi 1
+    # 2709 is pi 2
+    # Anything else is not a pi.
+    with open('/proc/cpuinfo', 'r') as infile:
+        cpuinfo = infile.read()
+    # Match a line like 'Hardware   : BCM2709'
+    match = re.search('^Hardware\s+:\s+(\w+)$', cpuinfo,
+                      flags=re.MULTILINE | re.IGNORECASE)
+    if not match:
+        # Couldn't find the hardware, assume it isn't a pi.
+        return None
+    if match.group(1) == 'BCM2708':
+        # Pi 1
+        return 1
+    elif match.group(1) == 'BCM2709':
+        # Pi 2
+        return 2
+    else:
+        # Something else, not a pi.
+        return None