It is a long time 🙂 I am back to SPI & MicroSD.

PS: PCB is ready today, and the boards has send to SMT/PCBA factory. Now the factory is counting the parts, the PCBA and test will start right now. Nothing is as easy as it looks. (Haha, Murphy’s theorem 🙂 )
Paypal is working now, finally…

After some dirty and dark code, RT5350 SPI driver function is almost there. (still need some fix and clean up the code!! I hope that will be done tmr 🙂 ) This code might help if anybody already on such thing.

The code is dirty, due to I write to SPI/GPIO register directly.
(I have read all pinctrl source code, all spi driver code, all spi-gpio driver code and related code, not exists such api/interface)

Code can be find here.spi-rt2880

What I have done:
1. setsck, setmosi, getmisi, chip_select, all functions work.
2. The pins(clk, mosi, miso, cs0, cs1) work normal in GPIO mode.
3. low speed mode (< 937.5KHz) and high speed mode (>= 937.5KHz) is able to switch smoothly.

Exists bug:
1. tf card plugin but the driver can not detect.
2. weird result from spidev_test.

root@OpenWrt:/dev# spidev_test -D/dev/spidev32766.1 -s10000000
spi mode: 0
bits per word: 8
max speed: 10000000 Hz (10000 KHz)

50 3F E0 00 3F FF 
FF FF FF FF FF F0 
5F FF FF FF FF FF 
FF FC 17 FF FF FF 
FF FF FF FF 05 FF 
FF FF FF FF FF FF 
C1 7F 
root@OpenWrt:/dev# spidev_test -D/dev/spidev32766.1 -s300000
spi mode: 0
bits per word: 8
max speed: 300000 Hz (300 KHz)

FF 05 FF FF FF FF 
FF FF FF FF FF FF 
FF 01 FF FF FF FF 
FF FF FF FF FF FF 
FF FF FF FF FF FF 
FF FF FF FF FF FF 
FF C0 

Note:
1. Directly write to register might collide. Pin control has a lock for that, but my current code do not care about that.
2. I do not worry about high speed/low speed change, there is no conflict. SPI doing its work in its own worker thread, one thread for one master, data is safe here.
3. CPU consume is low 🙂 Looks like this is a right way if we fix the bugs.

Any idea is welcome and appreciate 🙂