This series adds a DRM driver for the Solomon Systech SSD16xx family of
e-paper display controllers (SSD1673, SSD1680, SSD1681, SSD1683), starting
with support for the Gooddisplay GDEY042T81, a 4.2" 400×300 black-and-white
e-paper panel driven by the SSD1683 controller.
The driver is designed and architected keeping the bi-stable nature
and low-power requirements of epaper display based systems in mind
along with having adequate flexibility to support varying use-case
requirements for the e-paper display use-cases.
The driver integrates with the DRM atomic modesetting framework and
supports:
- SPI communication in both 4-wire mode (separate D/C GPIO) and
3-wire mode (9-bit SPI with embedded D/C# bit)
- Full 4-way rotation via the Data Entry Mode register, with no GPU
or memory-copy overhead
- Three independently selectable refresh waveforms: partial (~300–500 ms),
full (~1.5–2 s), and fast (~1.0–1.5 s)
- 3-colour BWR pixel classification for panels with a red RAM plane
- Pixel format support: XRGB8888 (color path) and R1 (native 1bpp,
zero-copy path)
- Runtime PM with configurable autosuspend: the controller enters
Mode 1 deep sleep (RAM retained) after an idle timeout, waking
transparently on the next frame update
- System suspend/resume: switches to Mode 2 deep sleep (maximum
power savings) on system suspend and rebuilds the pipeline on resume
- Runtime-configurable DRM plane properties for refresh mode, colour
mode, and session control (clear-on-init/close/disable, init-refresh
waveform); rotation is set at probe time from a device tree property,
and border waveform uses a fixed per-panel default
Changes from v1[0]:
- Restructured into 14 modular patches covering bindings, driver core,
features, and platform integration (was 6 patches in v1)
- Added comprehensive device-tree bindings support for vendor prefixes
and SSD16xx controller configurations
- Refactored driver architecture from drm/tiny panel driver to drm/solomon
bridge driver
- Switch to using GEM_SHMEM helpers
- Refactored data entry mode implementation
- Removed runtime-configurable rotation/border-waveform DRM properties and
their module params; rotation is now set via device tree, and border
waveform now uses an enhanced fixed per-panel default
- Added support for Solomon SSD1677 controller variant
- Improved session management with plane properties
- Added comprehensive power management support
- Support for panels with reversed RAM X order
- Dropped RGB888, RGB565, R8, NV12, NV16, YUYV, and UYVY format support;
driver now only exposes XRGB8888 and R1
This has been tested against my development branch [1] using attached
test suite [2] and logs[3], individual results[4] and result summary[5]
uploaded.
[0]: [V1 patch series]
https://lore.kernel.org/all/[email protected]/
[1]: [Development Branch]
https://github.com/devarsht/linux-next/tree/epaper_drm_misc_next_staging_27_09_26
[2]: [Test Suite]
https://github.com/devarsht/linux-next/tree/epaper_drm_misc_next_staging_27_09_26/tests_27sept_new
[3]: [Test Logs]
https://github.com/devarsht/linux-next/tree/epaper_drm_misc_next_staging_27_09_26/tests_27sept_new/logs
[4]: [Test Results]
https://github.com/devarsht/linux-next/tree/epaper_drm_misc_next_staging_27_09_26/tests_27sept_new/results
[5]: [Result Summary]
https://github.com/devarsht/linux-next/blob/epaper_drm_misc_next_staging_27_09_26/tests_27sept_new/results/run_all_20250529_190854.summary
Devarsh Thakkar (13):
dt-bindings: vendor-prefixes: Add Dalian Good Display Co., Ltd.
dt-bindings: display: Add Solomon SSD16xx e-paper controller binding
dt-bindings: display: solomon,ssd16xx: Add Solomon SSD1677 controller
drm/solomon: Add DRM driver for Solomon SSD16xx e-paper display
controllers
drm/solomon: ssd16xx: Add clear_on_init/close/disable session
management
drm/solomon: ssd16xx: Add support for Solomon SSD1677 controller
drm/solomon: ssd16xx: Add power management support
drm/solomon: ssd16xx: Expose refresh mode as plane property
drm/solomon: ssd16xx: Expose color mode as plane property
drm/solomon: ssd16xx: Expose session management as plane properties
MAINTAINERS: Add entry for Solomon SSD16xx DRM driver
arm64: defconfig: Enable DRM_SSD16XX for AM62L3 EVM
arm64: dts: ti: Add AM62L3 EVM overlay for GDEY042T81 e-paper display
LiangCheng Wang (1):
drm/solomon: ssd16xx: support panels whose RAM X order is reversed
.../bindings/display/solomon,ssd16xx.yaml | 88 +
.../devicetree/bindings/vendor-prefixes.yaml | 2 +
MAINTAINERS | 8 +
arch/arm64/boot/dts/ti/Makefile | 6 +
.../ti/k3-am62l3-evm-epaper-gdey042t81.dtso | 96 +
arch/arm64/configs/defconfig | 1 +
drivers/gpu/drm/solomon/Kconfig | 13 +
drivers/gpu/drm/solomon/Makefile | 1 +
drivers/gpu/drm/solomon/ssd16xx.c | 2607 +++++++++++++++++
9 files changed, 2822 insertions(+)
create mode 100644
Documentation/devicetree/bindings/display/solomon,ssd16xx.yaml
create mode 100644 arch/arm64/boot/dts/ti/k3-am62l3-evm-epaper-gdey042t81.dtso
create mode 100644 drivers/gpu/drm/solomon/ssd16xx.c
--
2.39.1
