kernel.git/include/drm/drm_mipi_dbi.h, branch linux-rolling-stable

drm/mipi-dbi: Add support for DRM_FORMAT_RGB888

2024-06-07T14:09:05Z

DRM_FORMAT_RGB888 is 24 bits per pixel and it would be natural to send it on the SPI bus using a 24 bits per word transfer. The problem with this is that not all SPI controllers support 24 bpw. Since DRM_FORMAT_RGB888 is stored in memory as little endian and the SPI bus is big endian we use 8 bpw to always get the same pixel format on the bus: b8g8r8. The MIPI DCS specification lists the standard commands that can be sent over the MIPI DBI interface. The set_address_mode (36h) command has one bit in the parameter that controls RGB/BGR order. This means that the controller can be configured to receive the pixel as BGR. RGB888 is rarely supported on these controllers but RGB666 is very common. All datasheets I have seen do at least support the pixel format option where each color is sent as one byte and the 6 MSB's are used. All this put together means that we can send each pixel as b8g8r8 and an RGB666 capable controller sees this as b6x2g6x2r6x2. v4: - s/emulation_format/pixel_format/ (Dmitry) Reviewed-by: Dmitry Baryshkov Link: https://patchwork.freedesktop.org/patch/msgid/20240604-panel-mipi-dbi-rgb666-v4-4-d7c2bcb9b78d@tronnes.org Signed-off-by: Noralf Trønnes

drm/mipi-dbi: Make bits per word configurable for pixel transfers

2024-06-07T14:09:05Z

MIPI DCS write/set commands have 8 bit parameters except for the write_memory commands where it depends on the pixel format. drm_mipi_dbi does currently only support RGB565 which is 16-bit and it has to make sure that the pixels enters the SPI bus in big endian format since the MIPI DBI spec doesn't have support for little endian. drm_mipi_dbi is optimized for DBI interface option 3 which means that the 16-bit bytes are swapped by the upper layer if the SPI bus does not support 16 bits per word, signified by the swap_bytes member. In order to support both 16-bit and 24-bit pixel transfers we need a way to tell the DBI command layer the format of the buffer. Add a write_memory_bpw member that the upper layer can use to tell how many bits per word to use for the SPI transfer. v4: - Expand the commit message (Dmitry) Reviewed-by: Dmitry Baryshkov Link: https://patchwork.freedesktop.org/patch/msgid/20240604-panel-mipi-dbi-rgb666-v4-3-d7c2bcb9b78d@tronnes.org Signed-off-by: Noralf Trønnes

drm/format-helper: Pass format-conversion state to helpers

2023-11-14T09:16:53Z

Pass an instance of struct drm_format_conv_state to DRM's format conversion helpers. Update all callers. Most drivers can use the format-conversion state from their shadow- plane state. The shadow plane's destroy function releases the allocated buffer. Drivers will later be able to allocate a buffer of appropriate size in their plane's atomic_check code. The gud driver uses a separate thread for committing updates. For now, the update worker contains its own format-conversion state. Images in the format-helper tests are small. The tests preallocate a static page for the temporary buffer. Unloading the module releases the memory. v6: * update patch for ssd132x support v5: * avoid using unusupported shadow-plane state in repaper (Noralf) * fix documentation (Noralf, kernel test robot) v3: * store buffer in shadow-plane state (Javier, Maxime) * replace ARRAY_SIZE() with sizeof() (Jani) Signed-off-by: Thomas Zimmermann Reviewed-by: Javier Martinez Canillas Tested-by: Javier Martinez Canillas # ssd130x Cc: Noralf Trønnes Cc: Javier Martinez Canillas Cc: Gerd Hoffmann Cc: David Lechner Link: https://patchwork.freedesktop.org/patch/msgid/20231009141018.11291-4-tzimmermann@suse.de

drm/mipi-dbi: Support separate I/O regulator

2022-12-14T13:57:09Z

The MIPI DBI specification defines separate vdd (panel power) and vddi (I/O voltage) supplies. Displays that require different voltages for the different supplies do exist, so the supplies cannot be combined into one as they are now. Add a new io_regulator property to the mipi_dbi_dev struct which can be set by the panel driver along with the regulator property. Signed-off-by: Otto Pflüger Reviewed-by: Noralf Trønnes Signed-off-by: Noralf Trønnes Link: https://patchwork.freedesktop.org/patch/msgid/20221201160245.2093816-2-otto.pflueger@abscue.de

drm/mipi-dbi: Support shadow-plane state

2022-12-05T13:20:43Z

Implement MIPI DBI planes with struct drm_shadow_plane_state, so that the respective drivers can use the vmap'ed GEM-buffer memory. Implement state helpers, the {begin,end}_fb_access helpers and wire up everything. With this commit, MIPI DBI drivers can access the GEM object's memory that is provided by shadow-plane state. The actual changes to drivers are implemented separately. v2: * use shadow-plane state directly (Noralf) Signed-off-by: Thomas Zimmermann Reviewed-by: Noralf Trønnes Tested-by: Javier Martinez Canillas Tested-by: Noralf Trønnes # drm/tiny/mi0283qt Link: https://patchwork.freedesktop.org/patch/msgid/20221202125644.7917-7-tzimmermann@suse.de

drm/mipi-dbi: Prepare framebuffer copy operation in pipe-update helpers

2022-12-05T12:36:33Z

Move the vmap/vunmap blocks from the inner fb_dirty helpers into the MIPI DBI update helpers. The function calls can result in waiting and/or processing overhead. Reduce the penalties by executing the functions once in the outer-most function of the pipe update. This change also prepares for MIPI DBI for shadow-plane helpers. With shadow-plane helpers, transfer source buffers are mapped into kernel address space automatically. v2: * keep each driver's existing buffer-mapping patter (Noralf) * zero-initialize iosys_map arrays (Noralf) Signed-off-by: Thomas Zimmermann Reviewed-by: Noralf Trønnes Tested-by: Javier Martinez Canillas Tested-by: Noralf Trønnes # drm/tiny/mi0283qt Link: https://patchwork.freedesktop.org/patch/msgid/20221202125644.7917-6-tzimmermann@suse.de

drm/mipi-dbi: Initialize default driver functions with macro

2022-12-05T12:36:16Z

Introduce DRM_MIPI_DBI_SIMPLE_DISPLAY_PIPE_FUNCS to initialize MIPI-DBI helpers to default values and convert drivers. The prepare_fb function set by some drivers is called implicitly by simple-kms helpers, so leave it out. Signed-off-by: Thomas Zimmermann Reviewed-by: Noralf Trønnes Tested-by: Javier Martinez Canillas Tested-by: Noralf Trønnes # drm/tiny/mi0283qt Link: https://patchwork.freedesktop.org/patch/msgid/20221202125644.7917-5-tzimmermann@suse.de

drm/probe-helper: Add drm_crtc_helper_mode_valid_fixed()

2022-09-12T07:14:26Z

Add drm_crtc_helper_mode_valid_fixed(), which validates a given mode against a display hardware's mode. Convert simpledrm and use it in a few other drivers with static modes. v4: * remove empty line after opening brace v2: * rename 'static' and 'hw' to 'fixed' everywhere Signed-off-by: Thomas Zimmermann Reviewed-by: Sam Ravnborg Link: https://patchwork.freedesktop.org/patch/msgid/20220905141648.22013-3-tzimmermann@suse.de

drm/mipi-dbi: Add driver_private member to struct mipi_dbi_dev

2022-02-28T09:29:33Z

devm_drm_dev_alloc() can't allocate structures that embed a structure which then again embeds drm_device. Workaround this by adding a driver_private pointer to struct mipi_dbi_dev which the driver can use for its additional state. v3: - Add documentation Acked-by: Maxime Ripard Acked-by: Sam Ravnborg Signed-off-by: Noralf Trønnes Signed-off-by: Maxime Ripard Link: https://patchwork.freedesktop.org/patch/msgid/20220227124713.39766-5-noralf@tronnes.org

drm/dbi: Use a static inline stub for mipi_dbi_debugfs_init()

2021-12-22T20:41:01Z

Replace the slightly odd "#define NULL" thing with a standard static inline stub. Cc: Noralf Trønnes Cc: Sam Ravnborg Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20211221193754.12287-2-ville.syrjala@linux.intel.com Reviewed-by: Jani Nikula