Add a common iMX MU driver in misc uclass to communicate with M4.
The MU message format is defined to use 4 words as below, the driver
will use all 4 TR/RR in MU to pass one message
|WORD 0 | WORD 1 | WORD 2 | WORD 3 |
|SEQ | TYPE | PAYLOAD ADDRESS | PAYLOAD LENGTH |
- SEQ:
A sequence id starts from 0 and increases for each request message
- TYPE:
0x1: Request. Message sent from AP will set to this value.
0x2: Response. Message responded from M4 set to this value.
0x3: MU A side is ready.
0x4: MU B side is ready.
- PAYLOAD ADDRESS:
A pointer to the memory address where the uplayer message is stored
- PAYLOAD LENGTH:
The uplayer message length
Signed-off-by: Ye Li <ye.li@nxp.com>
(cherry picked from commit aba0e51cc397e1d98be950f9c15619de06ebf782)
Ye Li