The Nuvoton MA35D1 SoC integrates a Verisilicon DCU Lite display controller. While its register layout is broadly similar to the DC8200, several differences require dedicated hardware ops:
1. No CONFIG_EX commit path: framebuffer updates use enable (bit 0) and reset (bit 4) bits in FB_CONFIG instead of the DC8200 staging registers (FB_CONFIG_EX, FB_TOP_LEFT, FB_BOTTOM_RIGHT, FB_BLEND_CONFIG, PANEL_CONFIG_EX). 2. No PANEL_START register: panel output starts when PANEL_CONFIG.RUNNING is set; no multi-display sync start register is used. 3. Different IRQ registers: DCU Lite uses DISP_IRQ_STA (0x147C) / DISP_IRQ_EN (0x1480) versus DC8200's TOP_IRQ_ACK (0x0010) / TOP_IRQ_EN (0x0014). 4. Per-frame commit cycle: DCU Lite requires the VALID bit in FB_CONFIG to be set at the start of each atomic commit (crtc_begin) and cleared after (crtc_flush). 5. Simpler clock topology: only "core" (bus gate) and "pix0" (pixel divider) clocks; no axi or ahb clocks. Make axi_clk and ahb_clk optional (devm_clk_get_optional_enabled) so DCU Lite nodes without those clocks are handled gracefully. Add vs_dcu_lite.c implementing the vs_dc_funcs vtable for the above differences. After chip identity detection, vs_dc_probe() now selects vs_dcu_lite_funcs when the identified model is VSDC_MODEL_DCU_LITE (model register reads 0, revision 0x5560, customer_id 0x305). Extend Kconfig to allow building on ARCH_MA35 platforms. Signed-off-by: Joey Lu <[email protected]> --- drivers/gpu/drm/verisilicon/Kconfig | 2 +- drivers/gpu/drm/verisilicon/Makefile | 2 +- drivers/gpu/drm/verisilicon/vs_dc.c | 9 ++- drivers/gpu/drm/verisilicon/vs_dc.h | 1 + drivers/gpu/drm/verisilicon/vs_dcu_lite.c | 78 +++++++++++++++++++++++ 5 files changed, 87 insertions(+), 5 deletions(-) create mode 100644 drivers/gpu/drm/verisilicon/vs_dcu_lite.c diff --git a/drivers/gpu/drm/verisilicon/Kconfig b/drivers/gpu/drm/verisilicon/Kconfig index 7cce86ec8603..295d246eb4b4 100644 --- a/drivers/gpu/drm/verisilicon/Kconfig +++ b/drivers/gpu/drm/verisilicon/Kconfig @@ -2,7 +2,7 @@ config DRM_VERISILICON_DC tristate "DRM Support for Verisilicon DC-series display controllers" depends on DRM && COMMON_CLK - depends on RISCV || COMPILE_TEST + depends on RISCV || ARCH_MA35 || COMPILE_TEST select DRM_BRIDGE_CONNECTOR select DRM_CLIENT_SELECTION select DRM_DISPLAY_HELPER diff --git a/drivers/gpu/drm/verisilicon/Makefile b/drivers/gpu/drm/verisilicon/Makefile index f4fbd9f7d6a2..bf88f627e65c 100644 --- a/drivers/gpu/drm/verisilicon/Makefile +++ b/drivers/gpu/drm/verisilicon/Makefile @@ -1,5 +1,5 @@ # SPDX-License-Identifier: GPL-2.0-only -verisilicon-dc-objs := vs_bridge.o vs_crtc.o vs_dc.o vs_dc8200.o vs_drm.o vs_hwdb.o vs_plane.o vs_primary_plane.o +verisilicon-dc-objs := vs_bridge.o vs_crtc.o vs_dc.o vs_dc8200.o vs_dcu_lite.o vs_drm.o vs_hwdb.o vs_plane.o vs_primary_plane.o obj-$(CONFIG_DRM_VERISILICON_DC) += verisilicon-dc.o diff --git a/drivers/gpu/drm/verisilicon/vs_dc.c b/drivers/gpu/drm/verisilicon/vs_dc.c index c94957024189..77bc63c629f7 100644 --- a/drivers/gpu/drm/verisilicon/vs_dc.c +++ b/drivers/gpu/drm/verisilicon/vs_dc.c @@ -90,13 +90,13 @@ static int vs_dc_probe(struct platform_device *pdev) return PTR_ERR(dc->core_clk); } - dc->axi_clk = devm_clk_get_enabled(dev, "axi"); + dc->axi_clk = devm_clk_get_optional_enabled(dev, "axi"); if (IS_ERR(dc->axi_clk)) { dev_err(dev, "can't get axi clock\n"); return PTR_ERR(dc->axi_clk); } - dc->ahb_clk = devm_clk_get_enabled(dev, "ahb"); + dc->ahb_clk = devm_clk_get_optional_enabled(dev, "ahb"); if (IS_ERR(dc->ahb_clk)) { dev_err(dev, "can't get ahb clock\n"); return PTR_ERR(dc->ahb_clk); @@ -134,7 +134,10 @@ static int vs_dc_probe(struct platform_device *pdev) dev_info(dev, "Found DC%x rev %x customer %x\n", dc->identity.model, dc->identity.revision, dc->identity.customer_id); - dc->funcs = &vs_dc8200_funcs; + if (dc->identity.model == VSDC_MODEL_DC8200) + dc->funcs = &vs_dc8200_funcs; + else + dc->funcs = &vs_dcu_lite_funcs; if (port_count > dc->identity.display_count) { dev_err(dev, "too many downstream ports than HW capability\n"); diff --git a/drivers/gpu/drm/verisilicon/vs_dc.h b/drivers/gpu/drm/verisilicon/vs_dc.h index 45172c1a525c..d77d4a1babdf 100644 --- a/drivers/gpu/drm/verisilicon/vs_dc.h +++ b/drivers/gpu/drm/verisilicon/vs_dc.h @@ -66,5 +66,6 @@ struct vs_dc { }; extern const struct vs_dc_funcs vs_dc8200_funcs; +extern const struct vs_dc_funcs vs_dcu_lite_funcs; #endif /* _VS_DC_H_ */ diff --git a/drivers/gpu/drm/verisilicon/vs_dcu_lite.c b/drivers/gpu/drm/verisilicon/vs_dcu_lite.c new file mode 100644 index 000000000000..11ef57d5ebaa --- /dev/null +++ b/drivers/gpu/drm/verisilicon/vs_dcu_lite.c @@ -0,0 +1,78 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2026 Joey Lu <[email protected]> + */ + +#include <linux/regmap.h> + +#include "vs_crtc_regs.h" +#include "vs_dc.h" +#include "vs_primary_plane_regs.h" + +static void vs_dcu_lite_bridge_enable(struct vs_dc *dc, unsigned int output) +{ + regmap_set_bits(dc->regs, VSDC_FB_CONFIG(output), + VSDC_FB_CONFIG_RESET); +} + +static void vs_dcu_lite_bridge_disable(struct vs_dc *dc, unsigned int output) +{ + regmap_clear_bits(dc->regs, VSDC_FB_CONFIG(output), + VSDC_FB_CONFIG_RESET); +} + +static void vs_dcu_lite_crtc_begin(struct vs_dc *dc, unsigned int output) +{ + regmap_set_bits(dc->regs, VSDC_FB_CONFIG(output), + VSDC_FB_CONFIG_VALID); +} + +static void vs_dcu_lite_crtc_flush(struct vs_dc *dc, unsigned int output) +{ + regmap_clear_bits(dc->regs, VSDC_FB_CONFIG(output), + VSDC_FB_CONFIG_VALID); +} + +static void vs_dcu_lite_crtc_enable(struct vs_dc *dc, unsigned int output) +{ + regmap_set_bits(dc->regs, VSDC_FB_CONFIG(output), + VSDC_FB_CONFIG_ENABLE); +} + +static void vs_dcu_lite_crtc_disable(struct vs_dc *dc, unsigned int output) +{ + regmap_clear_bits(dc->regs, VSDC_FB_CONFIG(output), + VSDC_FB_CONFIG_ENABLE); +} + +static void vs_dcu_lite_enable_vblank(struct vs_dc *dc, unsigned int output) +{ + regmap_set_bits(dc->regs, VSDC_DISP_IRQ_EN, + VSDC_DISP_IRQ_VSYNC(output)); +} + +static void vs_dcu_lite_disable_vblank(struct vs_dc *dc, unsigned int output) +{ + regmap_clear_bits(dc->regs, VSDC_DISP_IRQ_EN, + VSDC_DISP_IRQ_VSYNC(output)); +} + +static u32 vs_dcu_lite_irq_handler(struct vs_dc *dc) +{ + u32 irqs; + + regmap_read(dc->regs, VSDC_DISP_IRQ_STA, &irqs); + return irqs; +} + +const struct vs_dc_funcs vs_dcu_lite_funcs = { + .bridge_enable = vs_dcu_lite_bridge_enable, + .bridge_disable = vs_dcu_lite_bridge_disable, + .crtc_begin = vs_dcu_lite_crtc_begin, + .crtc_flush = vs_dcu_lite_crtc_flush, + .crtc_enable = vs_dcu_lite_crtc_enable, + .crtc_disable = vs_dcu_lite_crtc_disable, + .enable_vblank = vs_dcu_lite_enable_vblank, + .disable_vblank = vs_dcu_lite_disable_vblank, + .irq_handler = vs_dcu_lite_irq_handler, +}; -- 2.43.0
