[PATCH v10 03/14] media: iris: Add helper to create a context bank device

From: Vikash Garodia <[email protected]>

The subnode in the device tree is registered as a separate device so
that it gets its own IOMMU context. Pixel/non-pixel buffers are mapped
into these iommu domain, to ensure they are within the addressable range.

Co-developed-by: Vishnu Reddy <[email protected]>
Signed-off-by: Vishnu Reddy <[email protected]>
Signed-off-by: Vikash Garodia <[email protected]>
Tested-by: Daniel J Blueman <[email protected]>
---
 drivers/media/platform/qcom/iris/iris_resources.c | 28 +++++++++++++++++++++++
 drivers/media/platform/qcom/iris/iris_resources.h |  1 +
 2 files changed, 29 insertions(+)

diff --git a/drivers/media/platform/qcom/iris/iris_resources.c b/drivers/media/platform/qcom/iris/iris_resources.c
index 773f6548370a..a685915a19e9 100644
--- a/drivers/media/platform/qcom/iris/iris_resources.c
+++ b/drivers/media/platform/qcom/iris/iris_resources.c
@@ -5,6 +5,7 @@
 
 #include <linux/clk.h>
 #include <linux/devfreq.h>
+#include <linux/dma-mapping.h>
 #include <linux/interconnect.h>
 #include <linux/pm_domain.h>
 #include <linux/pm_opp.h>
@@ -141,3 +142,30 @@ int iris_disable_unprepare_clock(struct iris_core *core, enum platform_clk_type
 
 	return 0;
 }
+
+struct device *iris_create_cb_dev(struct iris_core *core, const char *name)
+{
+	struct platform_device_info plat_dev_info = {};
+	struct device_node *child_of_node;
+	struct platform_device *pdev;
+
+	child_of_node = of_get_child_by_name(core->dev->of_node, name);
+	if (!child_of_node)
+		return NULL;
+
+	plat_dev_info.dma_mask = core->iris_platform_data->dma_mask;
+	plat_dev_info.fwnode = &child_of_node->fwnode;
+	plat_dev_info.name = child_of_node->name;
+	plat_dev_info.id = PLATFORM_DEVID_AUTO;
+	plat_dev_info.parent = core->dev;
+
+	pdev = platform_device_register_full(&plat_dev_info);
+	of_node_put(child_of_node);
+	if (IS_ERR(pdev))
+		return ERR_CAST(pdev);
+
+	dma_set_max_seg_size(&pdev->dev, DMA_BIT_MASK(32));
+	dma_set_seg_boundary(&pdev->dev, DMA_BIT_MASK(32));
+
+	return &pdev->dev;
+}
diff --git a/drivers/media/platform/qcom/iris/iris_resources.h b/drivers/media/platform/qcom/iris/iris_resources.h
index 6bfbd2dc6db0..ca53c01f60ae 100644
--- a/drivers/media/platform/qcom/iris/iris_resources.h
+++ b/drivers/media/platform/qcom/iris/iris_resources.h
@@ -15,5 +15,6 @@ int iris_unset_icc_bw(struct iris_core *core);
 int iris_set_icc_bw(struct iris_core *core, unsigned long icc_bw);
 int iris_disable_unprepare_clock(struct iris_core *core, enum platform_clk_type clk_type);
 int iris_prepare_enable_clock(struct iris_core *core, enum platform_clk_type clk_type);
+struct device *iris_create_cb_dev(struct iris_core *core, const char *name);
 
 #endif

-- 
2.34.1