"""Find a VALID SwI2cRequest that the SMU accepts, before testing NumCmds bounds.
Driver builds: port=1, speed=I2C_SPEED_FAST_400K(2), cmds[0]|=RESTART, cmds[n-1]|=STOP.
READ commands only (READWRITE bit clear) -> nothing is written to any device.
"""
import time, struct
from tinygrad import Device
import tinygrad.runtime.autogen.am.smu_13_0_0 as smu
d=Device["AMD"]; adev=d.iface.dev_impl
TP=adev.smu.driver_table_paddr; SIZE=116
MSG=adev.mmMP1_SMN_C2PMSG_66; ARG=adev.mmMP1_SMN_C2PMSG_82; RESP=adev.mmMP1_SMN_C2PMSG_90
N={0:'BUSY',1:'OK',0xFF:'FAILED',0xFE:'UNKNOWN',0xFD:'BAD_PREREQ',0xFC:'REJ_BUSY',0xFB:'REJ_PREREQ'}
def send(msg,param=0,tmo=2.0):
    RESP.write(0); ARG.write(param&0xffffffff); MSG.write(msg)
    t0=time.monotonic()
    while time.monotonic()-t0<tmo:
        r=RESP.read()
        if r!=0: return N.get(r,hex(r)),(time.monotonic()-t0)*1000
    return 'TIMEOUT',(time.monotonic()-t0)*1000
def wr(b):
    v=adev.vram.view(TP,len(b),'I')
    for i in range(len(b)//4): v[i]=struct.unpack_from('<I',b,4*i)[0]
def rd():
    v=adev.vram.view(TP,SIZE,'I')
    return b''.join(struct.pack('<I',v[i]) for i in range(SIZE//4))
STOP=smu.CMDCONFIG_STOP_MASK; RESTART=smu.CMDCONFIG_RESTART_MASK; RW=smu.CMDCONFIG_READWRITE_MASK
def build(n, port, speed, slave, write=False):
    b=bytearray(SIZE)
    b[0]=port; b[1]=speed; b[2]=slave; b[3]=n&0xFF
    eff=min(n,24)
    for i in range(24):
        b[4+2*i]=0x00
        b[5+2*i]=(RW if write else 0)
    if eff>0:
        b[5]|=RESTART
        b[5+2*(eff-1)]|=STOP
    for off in range(52,SIZE): b[off]=0xCC
    return bytes(b)
print("=== find an accepted SwI2cRequest (READ cmds, no device writes) ===")
for port in (0,1):
    for speed in (1,2):
        for slave in (0x50,0xA0,0x18):
            wr(build(2,port,speed,slave))
            r,ms=send(smu.PPSMC_MSG_TransferTableDram2Smu,9)
            print("  port=%d speed=%d slave=%#04x n=2 -> %-8s %5.1fms"%(port,speed,slave,r,ms))
print()
print("MEMSIZE:",hex(adev.rreg(0xde3)))