[PATCH v3 14/16] drm: sprd: do not access IOMMU registers

From: Otto Pflüger
Date: Thu Jul 31 2025 - 11:53:38 EST


Changing the IOMMU registers results in conflicts with the sprd_iommu
driver. Remove all references to IOMMU registers in the graphics driver.

Signed-off-by: Otto Pflüger <otto.pflueger@xxxxxxxxx>
---
drivers/gpu/drm/sprd/sprd_dpu.c | 14 --------------
1 file changed, 14 deletions(-)

diff --git a/drivers/gpu/drm/sprd/sprd_dpu.c b/drivers/gpu/drm/sprd/sprd_dpu.c
index b946d015133db44d2d3d0b18803ed887b2b7ae2e..acf28de3fd08edaad03f01104f3e6cc7c243123c 100644
--- a/drivers/gpu/drm/sprd/sprd_dpu.c
+++ b/drivers/gpu/drm/sprd/sprd_dpu.c
@@ -55,14 +55,6 @@
#define REG_DPI_H_TIMING 0x1F4
#define REG_DPI_V_TIMING 0x1F8

-/* MMU control registers */
-#define REG_MMU_EN 0x800
-#define REG_MMU_VPN_RANGE 0x80C
-#define REG_MMU_PPN1 0x83C
-#define REG_MMU_RANGE1 0x840
-#define REG_MMU_PPN2 0x844
-#define REG_MMU_RANGE2 0x848
-
/* Global control bits */
#define BIT_DPU_RUN BIT(0)
#define BIT_DPU_STOP BIT(1)
@@ -410,12 +402,6 @@ static void sprd_dpu_init(struct sprd_dpu *dpu)
u32 dpu_version = readl(ctx->base + REG_DPU_VERSION);

writel(0x00, ctx->base + REG_BG_COLOR);
- writel(0x00, ctx->base + REG_MMU_EN);
- writel(0x00, ctx->base + REG_MMU_PPN1);
- writel(0xffff, ctx->base + REG_MMU_RANGE1);
- writel(0x00, ctx->base + REG_MMU_PPN2);
- writel(0xffff, ctx->base + REG_MMU_RANGE2);
- writel(0x1ffff, ctx->base + REG_MMU_VPN_RANGE);

if (ctx->if_type == SPRD_DPU_IF_DPI) {
/* use dpi as interface */

--
2.50.0