can not get adafruit_green display to run correctly on 5.x kernel

[rudiratlos]

I've figuered out, that adafruit_green is nearly compatible with sainsmart18 (st7735r driver). But adafruit_green buffer will start 2 colums further, compared to sainsmart18. That's why we will see pixel artefacts in top row and most left column of the adafruit display.

In the old module fbtft_device.c (not available in new kernel) there is a specific "adafruit18_green_tab_set_addr_win" function, which will cope with this 2 column offset. But unfortunatly fbtft_device.c will not be used anymore in new kernel. So there is no specfic setup for the adafruit display and we will see these ugly pixel artefacts.

How can I feed "set_addr_win" function with specifc adafruit display code??

code snippets, which will show the problem:

`In MIPI_DCS_SET_COLUMN_ADDRESS = 0x2A, MIPI_DCS_SET_PAGE_ADDRESS = 0x2B,

im linux staging code in st7735r.c als default static void set_addr_win(struct fbtft_par *par, int xs, int ys, int xe, int ye) { write_reg(par, MIPI_DCS_SET_COLUMN_ADDRESS, xs >> 8, xs & 0xFF, xe >> 8, xe & 0xFF);

write_reg(par, MIPI_DCS_SET_PAGE_ADDRESS,
      ys >> 8, ys & 0xFF, ye >> 8, ye & 0xFF);

write_reg(par, MIPI_DCS_WRITE_MEMORY_START);

}

adafruit_green specific code (fbtft_device.c is not available in new kernel): static void adafruit18_green_tab_set_addr_win(struct fbtft_par *par, int xs, int ys, int xe, int ye) { fbtft_par_dbg(DEBUG_SET_ADDR_WIN, par, "%s(xs=%d, ys=%d, xe=%d, ye=%d)\n", func, xs, ys, xe, ye); write_reg(par, 0x2A, 0, xs + 2, 0, xe + 2); write_reg(par, 0x2B, 0, ys + 1, 0, ye + 1); write_reg(par, 0x2C);

.bgr = true,

}`

[notro]

Ref: https://www.raspberrypi.org/forums/viewtopic.php?f=107&t=281204

[notro]

There are 2 solutions to this:

1. Add support to drivers/staging/fbtft/fb_st7735r.c
   This can be done by adding a struct fbtft_display and open coding FBTFT_REGISTER_DRIVER in order to add support for a second DT compatible string.

2. Add support to drivers/gpu/drm/tiny/st7735r.c
   See drm: Add support for Okaya RH128128T for how a similar display with pixel offsets was supported. Long term all fbtft drivers have to move to drm.

Restoring fbtft_device will not bring back support because it was already broken due to a gpio refactoring that broke things left and right.

fbtft doesn't have a maintainer that looks after it, and unfortunately I can't help you with this.

[inkyusa]

I guess this issue already resolved in https://github.com/raspberrypi/linux/commit/10de25851e6850e734f7655df9deea1eaedf0019. Haven't tested yet..

[rudiratlos]

my display works now. but still have problems with bgr. red color appears blue and blue appears red. the parameter bgr is not working

[rudiratlos]

pls. see: https://www.raspberrypi.org/forums/viewtopic.php?f=107&t=281204&start=25#p1730283

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