RE: SSD1306 OLED driver

Hi Noralf,

quoted

quoted

I am now concerned if the driver was tested in first place ?

No. I just submitted some good looking code that never ever got
tested.

More seriously, There's a few thing that comes to my mind:
- Your controller doesn't behave the same way than the ones already
supported.
- You haven't posted your changes yet, so maybe you're not doing the
transfers right
- Your SPI controller is doing something weird

What happens if you plug a logical analyzer on the bus?

Maxime

Hi,

The major difference between the SSD1306 SPI and I2C interfaces, is that 
SPI uses a D/C pin to signal whether it's data or command coming in.
Looking at ssd1307fb, this Data/Command info is embedded as the first 
byte in the i2c package/message.
Without looking up the datasheet, I would guess that this is the only 
difference, the way the D/C bit is handled.
The rest of the package payload should be the same.
So:
dc=0, spi write command
dc=1, spi write data (optional)

I was working on ssd1306 itself.

Apart from that, I have SSD1306 SPI support in a project of mine:

This is the part writing the framebuffer: 
https://github.com/notro/fbtft/blob/master/fb_ssd1306.c#L173
This writes commands (for many controllers): 
https://github.com/notro/fbtft/blob/master/fbtft-bus.c#L10
This is the SPI specific part: 
https://github.com/notro/fbtft/blob/master/fbtft-io.c#L10
Project wiki: https://github.com/notro/fbtft/wiki

Thanks for the pointers that was really helpful.

just a quick help the dc pin should be a gpio and be set as output pin
to control D/C ?
in my case for ssd1306 needs to be added as slave device in
board file since I dont have DT.

The code isn't particularly pretty, it was my first venture into the kernel.
It has recently been submitted for the staging tree: 
https://github.com/notro/fbtft/issues/161#issuecomment-68431405

hope it gets accepted soon.

Thanks,
--Sagar