RT5514_SPI_BUF_LEN
if (offset + RT5514_SPI_BUF_LEN <= len)
end = RT5514_SPI_BUF_LEN;
end = len % RT5514_SPI_BUF_LEN;
offset += RT5514_SPI_BUF_LEN;
write_buf = kmalloc(RT5514_SPI_BUF_LEN + 6, GFP_KERNEL);
if (offset + RT5514_SPI_BUF_LEN <= len)
end = RT5514_SPI_BUF_LEN;
end = len % RT5514_SPI_BUF_LEN;
offset += RT5514_SPI_BUF_LEN;