STM32MP1 pixel format RGB666

[mishuk]

Hello,

according to drivers/gpu/drm/stm/ltdc.c stm hardware supports these pixel formats:

enum ltdc_pix_fmt {
PF_NONE,
/* RGB formats */
PF_ARGB8888, /* ARGB [32 bits] */
PF_RGBA8888, /* RGBA [32 bits] */
PF_RGB888, /* RGB [24 bits] */
PF_RGB565, /* RGB [16 bits] */
PF_ARGB1555, /* ARGB A:1 bit RGB:15 bits [16 bits] */
PF_ARGB4444, /* ARGB A:4 bits R/G/B: 4 bits each [16 bits] */
/* Indexed formats */
PF_L8, /* Indexed 8 bits [8 bits] */
PF_AL44, /* Alpha:4 bits + indexed 4 bits [8 bits] */
PF_AL88 /* Alpha:8 bits + indexed 8 bits [16 bits] */
};

which corresponds to list of pixel format that I get from modetest -M stm | grep format:

formats: AR24 XR24 RG24 RG16 AR15 XR15 AR12 XR12 C8

My question is : does STM hardware support RGB666 pixel format ?  If yes, how should I patch stm driver to handle this pixel format ?

[Olivier GALLIEN]

Hi @mishuk ,

may this 2 related post help ? 

Solved: question about stm32mp1 LTDC PIN configuration - STMicroelectronics Community

STM32MP157 LTDC RGB666 - STMicroelectronics Community

Olivier

[mishuk]

No, these posts won`t help.  I asked not about Device Tree Configuration, but about RGB control inside hardware and corresponding driver. Current STM driver implementation (drivers/gpu/drm/stm/ltdc.c) lacks pixel format RGB666.  I ask, how can I add this pixel format, if it is supported by STM hardware. If it is not supported, I suppose, it makes no sense for adding pixel format inside driver.