Low-level access to Kobo eink panel

[giorgio130]

I've started hacking on the screen level on the Kobo platform.
It seems all the code we need to drive the panel is in the kernel source, under linux-2.6.35.3/drivers/video/mxc; in particular the relevant files are attached to this post.
"epdfb_dc.c" is already compilable as a stand-alone program, provided you add a "main" function to it.
I'm trying to do something useful with those functions but I haven't figured out yet how to use them. I'm sharing the info in case someone else wants to work on this.

[iToast]

_fb_gray_8to4 seems to convert a 8 bit buffer data object into a 4 bit one for older 4 bit kobos.

_fb_Gray4toRGB565 seems to convert it to RGB (why?)

_fb_Gray8toRGB565 as well but for a 8 bit FB

_fb_RGB565toGray4 as well but for a 4 bit FB

_fb_gray_4to8 Convert a gray 4 bit buffer to a 8 bit one for a kobo with a 8 bit FB

epdfbdc_create_ex2 seems to create a FB from a data stream?

epdfbdc_create_ex Does the above?

epdfbdc_create Does the above?

epdfbdc_delete destroys frame buffer

epdfbdc_fbimg_normallize normalizes a FB

_pixel_value_convert converts a pixel value (used for converting FB?)

_epdfbdc_get_dcimg_ptr ??? May convert image to FB?

_epdfbdc_get_img_pixelvalue_from_ptr get pixel data from pointer

_epdfbdc_set_dcpixel_at_ptr Change pixel data with pointer

_epdfbdc_get_img_pixelvalue Gets pixel values of whole image and returns them for use to print to screen?

_epdfbdc_set_pixel sets pixel in provided FB?

epdfbdc_put_fbimg push's image to frame buffer

epdfbdc_get_rotate_active checks if rotating FB

epdfbdc_set_pixel set pixel in FB

epdfbdc_dcbuf_to_RGB565 ???

epdfbdc_get_dirty_region used for dirty region update method

epdfbdc_rotate rotates FB?

epdfbdc_set_host_dataswap Creates swap for FB?

epdfbdc_set_drive_dataswap repeated?

epdfbdc_set_skip_pixel sets pixel to skip?



All of them also seem to put a debug out possibly on the internal serial connector. Probably for debug during development

[auspex]

Originally Posted by iToast

_fb_Gray4toRGB565 seems to convert it to RGB (why?)

Is the question why you need to convert from Gray-scale, or why to RGB? As I understand it, images are actually in RGB.