MPC_I2C_DR
readb(i2c->base + MPC_I2C_DR); /* init xfer */
readb(i2c->base + MPC_I2C_DR);
readb(i2c->base + MPC_I2C_DR);
val = readb(i2c->base + MPC_I2C_DR);
val = readb(i2c->base + MPC_I2C_DR);
writeb((msg->addr << 1) | dir, i2c->base + MPC_I2C_DR);
readb(i2c->base + MPC_I2C_DR);
byte = readb(i2c->base + MPC_I2C_DR);
writeb(msg->buf[i2c->byte_posn++], i2c->base + MPC_I2C_DR);