echo 1 > sys/class/graphics/fb0/rotate ,will rotate 180 degrees.
and see the define in ipu.h
IPU_ROTATE_NONE = 0,
IPU_ROTATE_VERT_FLIP = 1,
IPU_ROTATE_HORIZ_FLIP = 2,
IPU_ROTATE_180 = 3,
IPU_ROTATE_90_RIGHT = 4,
IPU_ROTATE_90_RIGHT_VFLIP = 5,
IPU_ROTATE_90_RIGHT_HFLIP = 6,
IPU_ROTATE_90_LEFT = 7,
write any value of 2 to 7 can't rotate the screen.
how to rotate 90 degrees for fb0.
board imx6q kernel 3.10.53
android is linux-2.6-imx.git - Freescale i.MX Linux Tree
the screen size is 1024*600
and try to rotate the kernel logo with boot args fbcon=rotate:3 will case kernel reset and can't get any debug message.
you can refer to the link as below, hope helpful for you:
About rotation of the display and touch function on MX6DL-SABER-SDP
https://community.nxp.com/message/619464?commentID=619464#comment-619464