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

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Message-Id: <20250731-ums9230-drm-v3-14-06d4f57c4b08@abscue.de>
Date: Thu, 31 Jul 2025 17:51:27 +0200
From: Otto Pflüger <otto.pflueger@...cue.de>
To: David Airlie <airlied@...il.com>, Simona Vetter <simona@...ll.ch>, 
 Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>, 
 Maxime Ripard <mripard@...nel.org>, Thomas Zimmermann <tzimmermann@...e.de>, 
 Rob Herring <robh@...nel.org>, Krzysztof Kozlowski <krzk+dt@...nel.org>, 
 Conor Dooley <conor+dt@...nel.org>, Orson Zhai <orsonzhai@...il.com>, 
 Baolin Wang <baolin.wang@...ux.alibaba.com>, 
 Chunyan Zhang <zhang.lyra@...il.com>, Kevin Tang <kevin.tang@...soc.com>, 
 Liviu Dudau <Liviu.Dudau@....com>, 
 Russell King <rmk+kernel@....linux.org.uk>, Eric Anholt <eric@...olt.net>, 
 Kevin Tang <kevin3.tang@...il.com>
Cc: dri-devel@...ts.freedesktop.org, devicetree@...r.kernel.org, 
 linux-kernel@...r.kernel.org, 
 Otto Pflüger <otto.pflueger@...cue.de>
Subject: [PATCH v3 14/16] drm: sprd: do not access IOMMU registers

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@...cue.de>
---
 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