This series adds support for the Verisilicon DCUltraLite display controller as integrated in the Nuvoton MA35D1 SoC.
The Verisilicon DC driver and its DT binding were originally written by Icenowy Zheng <[email protected]> for the T-Head TH1520 SoC, which carries a DC8200 IP block. The present series builds on that foundation with gratitude to Icenowy for the original work. The DCUltraLite is a different variant in the DC IP family. While the two IPs share a broadly similar register layout, a number of differences prevent the existing driver from working on the MA35D1 without modification: - No CONFIG_EX commit path: the DC8200 staging registers (FB_CONFIG_EX, FB_TOP_LEFT, FB_BOTTOM_RIGHT, FB_BLEND_CONFIG, PANEL_CONFIG_EX) are absent. The DCUltraLite uses enable (bit 0) and reset (bit 4) bits in FB_CONFIG for direct framebuffer updates, and requires a per-frame VALID bit toggle (FB_CONFIG bit 3) to latch configuration changes. - No PANEL_START register: panel output begins when PANEL_CONFIG.RUNNING is set; the DC8200 multi-display sync start register at 0x1CCC does not exist. - Different IRQ registers: DISP_IRQ_STA at 0x147C / DISP_IRQ_EN at 0x1480, versus the DC8200's TOP_IRQ_ACK at 0x0010 / TOP_IRQ_EN at 0x0014. - Simpler clock topology: two clocks ("core" bus gate and "pix0" pixel divider); no axi or ahb clocks required. - Single display output: no per-output indexing beyond index 0 is needed. - Hardware-discoverable identity: the DCUltraLite exposes chip identity registers whose model field reads 0x0 (revision 0x5560, customer_id 0x305), allowing the existing vs_fill_chip_identity() path to identify the variant purely through register reads. Patch 1 generalises the verisilicon,dc DT binding to accommodate the Nuvoton MA35D1 SoC-specific compatible and the variant's two-clock, one-reset, single-port topology. Patch 2 adds the register-level macros needed by the DCUltraLite ops. Patches 3-5 introduce the driver changes in three logical steps: the vs_dc_funcs hardware ops vtable with DC8200 ops extracted into vs_dc8200.c; the DCUltraLite ops in vs_dcu_lite.c with the necessary Kconfig and clock-optionality changes; and finally the DCUltraLite HWDB entry that gates hardware recognition once all support is in place. All patches have been tested on Nuvoton MA35D1 hardware. Changes from v2: - [dt-bindings] Replaced standalone verisilicon,dc compatible with the SoC-specific nuvoton,ma35d1-dcu added to the existing enum list, paired with verisilicon,dc as the generic fallback; this matches the thead,th1520-dc8200 pattern and was explicitly requested by the reviewer. - [dt-bindings] Removed standalone 'port' property; kept 'ports' in the global required list; MA35D1 example now uses ports/port@0 structure, following reviewer feedback that a 'port' alias should not be added since DC8000 (single-port) also supports DP output. - [dt-bindings] Replaced additionalProperties with unevaluatedProperties to allow per-variant if/then clauses to add constraints cleanly. - [dt-bindings] Added separate allOf/if block for nuvoton,ma35d1-dcu constraining clock-names to [core, pix0] and reset-names to [core]; the if/else structure from v2 is replaced by two independent if blocks. - [dt-bindings] Removed all description strings from if/then branches per reviewer request; descriptions remain only in the top-level properties. - [hwdb] Removed VSDC_MODEL_DC8200 and VSDC_MODEL_DCU_LITE macros; HWDB entries use literal values (0x8200, 0x0) with inline comments. - [hwdb] Added enum vs_dc_generation (VSDC_GEN_DC8000 / VSDC_GEN_DC8200) and a generation field to vs_chip_identity; funcs dispatch now uses generation instead of the model register value, per reviewer suggestion (DC8000 has model 0x8000 yet behaves like DCUltraLite with model 0x0). - [hwdb] Moved the DCUltraLite HWDB entry to the final patch in the series per reviewer request, making it a gate that is opened only after all supporting code is in place. - [ops] Split v2 patch 2 into two patches: register macros first, then the per-variant ops table, per reviewer suggestion. - [ops] Extracted DC8200-specific ops into vs_dc8200.c; DCUltraLite ops are in vs_dcu_lite.c; dispatch in vs_dc_probe uses generation field. Joey Lu (5): dt-bindings: display: verisilicon,dc: generalize for single-output variants drm/verisilicon: add register-level macros for DCU Lite drm/verisilicon: introduce per-variant hardware ops table drm/verisilicon: add Nuvoton MA35D1 DCU Lite display controller support drm/verisilicon: add DCUltraLite chip identity to HWDB .../bindings/display/verisilicon,dc.yaml | 103 ++++++++++++++--- drivers/gpu/drm/verisilicon/Kconfig | 2 +- drivers/gpu/drm/verisilicon/Makefile | 2 +- drivers/gpu/drm/verisilicon/vs_bridge.c | 20 +--- drivers/gpu/drm/verisilicon/vs_crtc.c | 38 ++++++- drivers/gpu/drm/verisilicon/vs_crtc_regs.h | 1 + drivers/gpu/drm/verisilicon/vs_dc.c | 13 ++- drivers/gpu/drm/verisilicon/vs_dc.h | 33 ++++++ drivers/gpu/drm/verisilicon/vs_dc8200.c | 107 ++++++++++++++++++ drivers/gpu/drm/verisilicon/vs_dcu_lite.c | 78 +++++++++++++ drivers/gpu/drm/verisilicon/vs_hwdb.c | 14 +++ drivers/gpu/drm/verisilicon/vs_hwdb.h | 6 + .../gpu/drm/verisilicon/vs_primary_plane.c | 32 +----- .../drm/verisilicon/vs_primary_plane_regs.h | 3 + 14 files changed, 385 insertions(+), 67 deletions(-) create mode 100644 drivers/gpu/drm/verisilicon/vs_dc8200.c create mode 100644 drivers/gpu/drm/verisilicon/vs_dcu_lite.c -- 2.43.0
