From e649ca006e7013bccffc64cc11524692038174dd Mon Sep 17 00:00:00 2001
From: Jianqun Xu <jay.xu@rock-chips.com>
Date: Mon, 23 Aug 2021 14:22:03 +0800
Subject: [PATCH] rknpu: add fake platform device to rknpu device

The device 'fake_dev' under rknpu_dev is registered by rknpu_drv, which
is a virtual platform device.

The rknpu partial sync should use a platform device without iommu, so to
use rknpu_dev->fake_dev.

Change-Id: I33f1b05d308063f235d31044f8e562755c1217f4
Signed-off-by: Jianqun Xu <jay.xu@rock-chips.com>
Signed-off-by: Felix Zeng <felix.zeng@rock-chips.com>
---
 drivers/rknpu/include/rknpu_drv.h |  2 ++
 drivers/rknpu/rknpu_drv.c         | 42 +++++++++++++++++++++++++++++++
 drivers/rknpu/rknpu_gem.c         | 16 +++++++-----
 3 files changed, 54 insertions(+), 6 deletions(-)

diff --git a/drivers/rknpu/include/rknpu_drv.h b/drivers/rknpu/include/rknpu_drv.h
index 84623a271a56..9683aa65f868 100644
--- a/drivers/rknpu/include/rknpu_drv.h
+++ b/drivers/rknpu/include/rknpu_drv.h
@@ -40,6 +40,7 @@
 struct rknpu_config {
 	__u32 bw_priority_base;
 	__u32 bw_priority_length;
+	__u64 dma_mask;
 };
 
 /**
@@ -52,6 +53,7 @@ struct rknpu_config {
 struct rknpu_device {
 	void __iomem *base;
 	struct device *dev;
+	struct device *fake_dev;
 	struct drm_device *drm_dev;
 	atomic_t sequence;
 	spinlock_t lock;
diff --git a/drivers/rknpu/rknpu_drv.c b/drivers/rknpu/rknpu_drv.c
index c1e1134422f2..c6d3fb9b3e8f 100644
--- a/drivers/rknpu/rknpu_drv.c
+++ b/drivers/rknpu/rknpu_drv.c
@@ -49,6 +49,7 @@ MODULE_PARM_DESC(bypass_irq_handler,
 static const struct rknpu_config rk356x_rknpu_config = {
 	.bw_priority_base = 0xfe180008,
 	.bw_priority_length = 0x10,
+	.dma_mask = DMA_BIT_MASK(32),
 };
 
 /* driver probe and init */
@@ -247,6 +248,42 @@ static bool rknpu_is_iommu_enable(struct device *dev)
 	return true;
 }
 
+static int drm_fake_dev_register(struct rknpu_device *rknpu_dev)
+{
+	const struct platform_device_info rknpu_dev_info = {
+		.name = "rknpu_dev",
+		.id = PLATFORM_DEVID_AUTO,
+		.dma_mask = rknpu_dev->config->dma_mask,
+	};
+	struct platform_device *pdev = NULL;
+	int ret = -EINVAL;
+
+	pdev = platform_device_register_full(&rknpu_dev_info);
+	if (pdev) {
+		ret = of_dma_configure(&pdev->dev, NULL, true);
+		if (ret) {
+			platform_device_unregister(pdev);
+			pdev = NULL;
+		}
+	}
+
+	rknpu_dev->fake_dev = pdev ? &pdev->dev : NULL;
+
+	return ret;
+}
+
+static void drm_fake_dev_unregister(struct rknpu_device *rknpu_dev)
+{
+	struct platform_device *pdev = NULL;
+
+	if (!rknpu_dev->fake_dev)
+		return;
+
+	pdev = to_platform_device(rknpu_dev->fake_dev);
+
+	platform_device_unregister(pdev);
+}
+
 static int rknpu_drm_probe(struct rknpu_device *rknpu_dev)
 {
 	struct device *dev = rknpu_dev->dev;
@@ -265,6 +302,8 @@ static int rknpu_drm_probe(struct rknpu_device *rknpu_dev)
 	drm_dev->dev_private = rknpu_dev;
 	rknpu_dev->drm_dev = drm_dev;
 
+	drm_fake_dev_register(rknpu_dev);
+
 	return 0;
 
 err_free_drm:
@@ -281,7 +320,10 @@ static void rknpu_drm_remove(struct rknpu_device *rknpu_dev)
 {
 	struct drm_device *drm_dev = rknpu_dev->drm_dev;
 
+	drm_fake_dev_unregister(rknpu_dev);
+
 	drm_dev_unregister(drm_dev);
+
 #if KERNEL_VERSION(4, 15, 0) <= LINUX_VERSION_CODE
 	drm_dev_put(drm_dev);
 #else
diff --git a/drivers/rknpu/rknpu_gem.c b/drivers/rknpu/rknpu_gem.c
index 5f4d6ff99472..45045723eb22 100644
--- a/drivers/rknpu/rknpu_gem.c
+++ b/drivers/rknpu/rknpu_gem.c
@@ -935,6 +935,11 @@ int rknpu_gem_sync_ioctl(struct drm_device *dev, void *data,
 						      DMA_FROM_DEVICE);
 		}
 	} else {
+		struct drm_device *drm = rknpu_obj->base.dev;
+		struct rknpu_device *rknpu_dev = drm->dev_private;
+
+		WARN_ON(!rknpu_dev->fake_dev);
+
 		length = args->size;
 		offset = args->offset;
 
@@ -951,15 +956,14 @@ int rknpu_gem_sync_ioctl(struct drm_device *dev, void *data,
 
 			if (args->flags & RKNPU_MEM_SYNC_TO_DEVICE) {
 				dma_sync_single_range_for_device(
-					dev->dev, sg_dma_addr, sg_offset, size,
-					DMA_TO_DEVICE);
+					rknpu_dev->fake_dev, sg_dma_addr,
+					sg_offset, size, DMA_TO_DEVICE);
 			}
 
 			if (args->flags & RKNPU_MEM_SYNC_FROM_DEVICE) {
-				dma_sync_single_range_for_cpu(dev->dev,
-							      sg_dma_addr,
-							      sg_offset, size,
-							      DMA_FROM_DEVICE);
+				dma_sync_single_range_for_cpu(
+					rknpu_dev->fake_dev, sg_dma_addr,
+					sg_offset, size, DMA_FROM_DEVICE);
 			}
 
 			offset += size;