Add EEPROM file

Python/components/eepromat24c_comp.py

+"""
+Management of AT24C0XC EEPROMs
+
+17/01/2018:EEPROM AT24C0XC
+This code is running on board V2
+"""
+# -*- coding: iso-8859-1 -*-
+
+import time
+from lli import i2c
+
+class EepromAT24C(object):
+    """ Class to manage the AT24C0XC EEPROM.
+    """
+
+    MAX_CHARS = 1000/8 # 1K
+
+    def __init__(self, dev, bus, add=0):
+        self.dev = dev
+        self.bus = bus
+        self.add = add
+
+    def init_mem(self, car='\0'):
+        """Init the full memory bytes with the NULL value
+        """
+        for pos in range(self.MAX_CHARS):
+            self.write_single(pos, ord(car))
+        for pos in range(self.MAX_CHARS):
+            if self.read_single(pos) != ord(car):
+                print ("ERROR init : pos ", pos, " cur ", self.read_single(pos), " is not ", ord(car))
+        print ("init mem done")
+
+    def read_single(self, reg):
+        """ Read at the position reg [] in byte in the eeprom
+        """
+        res = None
+        res = i2c.read(self.dev, self.bus, self.add, reg)
+        time.sleep(0.01)
+        return res[1]
+
+    def write_single(self, reg, val):
+        """ Write value val at the position reg in byte in the eeprom
+        """
+        res = None
+        res = i2c.write(self.dev, self.bus, self.add, reg, val)
+        time.sleep(0.01)
+        return res[1]
+
+    def read_string(self, reg, car='\0'):
+        """ Read a string terminated by the car "car" starting at position reg
+            returns a the string with the ending car
+        """
+        pos = reg
+        strg = ""
+        while True:
+            cur = self.read_single(pos)
+            strg = chr(cur) if strg is None else strg + chr(cur)
+            if (cur == ord(car)) or (len(strg) >= (self.MAX_CHARS - reg)):
+                break
+            pos = pos + 1
+         # necessary when several read in sequence are done to prevent loss!
+        time.sleep(0.01)
+        return strg
+
+    def write_string(self, reg, txt):
+        """Write the string txt in the eeprom starting at position reg
+        """
+        pos = reg
+        for cur in txt:
+            self.write_single(pos, ord(cur))
+            if self.read_single(pos) != ord(cur):
+                print ("Error write at pos ", pos)
+            if pos >= (self.MAX_CHARS):
+                break
+            pos = pos + 1
+            time.sleep(0.01)
+
+    def store_identification(self, id_string):
+        """Write the passed string as the identification code into the eeprom
+        """
+        self.write_string(0, id_string+'\0')
+
+    def read_identification(self):
+        """Read the identification string from the eeprom
+        """
+        val = self.read_string(0, car='}')
+
+        # protection against \xff\xff\....
+        if len(val) > 0 and val[0] == "\xff":
+            val = "?"*len(val)
+
+        return val
+
+
+def do_test(dev, bus, add):
+    """Test accesses to the mezzanine and board eeproms
+    """
+    dum_code = "OPQRSTU9876543210"
+
+    mezz = EepromAT24C(dev, bus, add)
+
+    #mezz.init_mem()
+    print (mezz.read_string(0)) # check meme is full of NULL chars
+
+    #mezz.write_string(0, dum_code)
+    print (mezz.read_string(0, car="U"))
+    print (mezz.read_string(0))
+    print (mezz.read_string(7, car="2"))
+
+    board_id = "p40_fv21prXXX"
+
+    mezz.store_identification(board_id)
+    print (mezz.read_identification())
+
+    print ("test done")
+
+def do_debug(dev):
+    import addresses_comp as const
+    mezz = EepromAT24C(dev, const.EEPROM_FPGA_BUS, const.EEPROM_U64_ADD)
+    print (mezz.read_identification())
+
+def main():
+    """Main test script
+    """
+    import addresses_comp as const
+
+    # do_test(0, const.EEPROM_FPGA_BUS, const.EEPROM_U64_ADD) # main board
+    # do_test(0, const.LTC2990_PWR_BUS, const.EEPROM_U19_ADD) # main board
+
+    for dev in (0, 2, 4, 6, 8, 10, 12, 14):
+        print "Board in logical slot ", dev
+        board = EepromAT24C(dev, const.EEPROM_FPGA_BUS, const.EEPROM_U64_ADD)
+        print board.read_identification()
+        mezz = EepromAT24C(dev, const.LTC2990_PWR_BUS, const.EEPROM_U19_ADD)
+        print mezz.read_identification()
+        print
+
+if __name__ == "__main__":
+    main()
+    print("board 0")
+    do_debug(0)
+    print("board 2")
+    do_debug(2)