Salve
Well Cybele or Kybele, is the Phrygian Mother Goddess equated with the Hellenic goddess Rhea. From what I know is that Attis was not her son, but her lover. The reason why Rhea is also called Kybele because after the Titanomachy, when she didn't get her dues of her son Zeus, she thaught she deserved, Rhea retreated to the mountain Kybele in Phrygia with her attendents; the Korybantes.
Kybele herself was a Mother Goddess who was already worshipped in Asia Minor since Neolithic times. She embodies the the fertile earth, a goddess of caverns and mountains, walls and fortresses, nature, wild animals (especially lions and bees). Her title 'Mistress of the Animals,' which is also borne by the Minoan Great Mother, reveals her ancient Paleolithic roots. The cult of Attis, her consort was introduced later. Kybele is said to have been born on Mount Ida in Asia Minor.
Cybele's most ecstatic followers were castrated males called Galli by the romans, who led the people in orgiastic ceremonies with wild music, drumming and dancing and drink. She was associated with the mystery religion concerning her son, Attis, who was castrated and resurrected. The Dactyls were part of her retinue. Other followers of Cybele, Phrygian kurbantes or Corybantes expressed her ecstatic and orgiastic cult in music especially drumming, clashing of shields and spears, dancing, singing, shouts, all at night. Atalanta and Hippomenes were turned into lions by Cybele after having sex in one of her temples.
Attis is also known as Agdistis, named after the mountain which he probably personified. He is the eunuch attendant of Kybele and drives the lion-driven chariot. He castrated himself after Kybele drove him mad.
for more information check these two pages:
http://en.wikipedia.org/wiki/Cybele
http://en.wikipedia.org/wiki/Attis
vale
Quintus