/* write field of ipu registers, without affecting other bits. */
uint32_t ipu_read(int32_t ipu_index, uint32_t ID_addr)
/* write field of ipu registers, without affecting other bits. */
uint32_t ipu_read(int32_t ipu_index, uint32_t ID_addr)
{
    uint32_t rdata;
    ID_addr += REGS_IPU_BASE(ipu_index);
    rdata = readl(ID_addr);
    return rdata;
}