ili9341: mipi-dbi-mode setable through DT

[ts4ling]

Currently ili9xxx only supports SPI, but there is also a 8 and 16-bit interface with different modes, see MIPI-DBI driver APIs. STM calls it flexible memory controller, other vendors will have a similar interface.

My PR allows to set different modes that must be supported by the parent device. Regarding STM it's mipi_dbi_stm32_fmc.c, that checks for MIPI_DBI_MODE_8080_BUS_16_BIT. My fix allows to set the mode accordingly and the configuration check passes.

To not break any existing DTs I made the mode setting optional.

	ili9341: lcd-panel@0 {
		compatible = "ilitek,ili9341";
		reg = <0>;
		pixel-format = <ILI9XXX_PIXEL_FORMAT_RGB565>;
		mipi-mode = <MIPI_DBI_MODE_8080_BUS_16_BIT>;
		mipi-max-frequency = <DT_FREQ_M(20)>;
// (..)
	};

[ts4ling]

I'd solve this, but those error texts don't help.

[danieldegrasse]

I'd solve this, but those error texts don't help.

Indeed, those don't look so helpful. Not sure why you can't see it but this looks like the issue:

 Devicetree Bindings:'required: false' is redundant, please remove
File:dts/bindings/display/ilitek,ili9xxx-common.yaml
Line:40

[danieldegrasse]

You don't need to add this- the property already exists in mipi-dbi-device.yaml:

zephyr/dts/bindings/mipi-dbi/mipi-dbi-device.yaml

Line 15 in 86af9c4

mipi-mode:

[danieldegrasse]

If you want to reformat the #define block (either for personal preference or to get clang-format to stop complaining), that is ok, but please make one commit that performs the reformat and another performing the functional change. Mixing formatting changes with functional ones in a single commit makes the git blame much harder to follow.

[ts4ling]

I wanted to reformat the file, but it also affected the look-up-table in the beginning

const uint8_t ili9xxx_rgb_lut[] = {
	0, 2, 4, 6,
	8, 10, 12, 14,
	16, 18, 20, 22,
	24, 26, 28, 30,

which is more readable this way. git add file.c -p joined the LUT with the next function and turned it into too much work to make "right". So I undid the clang-format and pushed my initial change again.

[ts4ling]

Since my intended changes were also included in PR-78453, this PR is obsolete.