This is very inconvenient, is also not good integration, which is used to code in the upper, a project recently, need to use spi, so I think can't add a standard spi driver, like a serial port, by opening the device node to spi operation, but the driver debugging itself difficulty big,
Also nothing important good idea at the beginning, after consult the Goodman, a great god gave me some ideas, and try to make the things, a lot of problems among them, the appearance of about four or five days, finally get out, share with you, this time to write out a column may write not over ah, this thing is more, think points several times to write all the detail, I hope you to help you see that??
First provided a train of thought, pure hand, add do not represent themselves to write one, and the difficulty is too large, also need to spend too much time, (of course if there is a great god he could fix it when I didn't say, estimates that the great god will not see the posts that I wrote it, ha ha ha ha.) we don't need their pure hand, 20 dv200 board has no standard spi driver, but there are other boards, 16 a, 20 dv400 some, there are 31 d,
We can refer to other driver code in the SDK, own to add, this is the most critical thinking,??
According to the idea of the first step is to compare the difference of register, find dv200 20, 20 dv400 and 16 a document, open, as follows: 20 dv200:
16 a
Comparison, only 20 dv200 0 x024 DMA registers are not, other are all the same, never felt this things, even if does not support DMA communication can be done at least, he opens the SDK code, began to compare, adding in the 20 d standard SPI driver, rounding - (2) and (3) give you tell me the code in detail how to compare and modify,
https://www.ebaina.com/articles/140000003972