[PATCH 2/3] iommu: add a connect op

[Caleb Connolly]

Add an optional iommu callback to be invoked before a device probes.
This can be used to configure the IOMMU in preparation for the device
(e.g. by allocating a context bank)

Signed-off-by: Caleb Connolly <caleb.connolly at linaro.org>
---
 drivers/iommu/iommu-uclass.c | 11 +++++++++++
 include/iommu.h              |  9 +++++++++
 2 files changed, 20 insertions(+)

diff --git a/drivers/iommu/iommu-uclass.c b/drivers/iommu/iommu-uclass.c
index 98731d5e2c44..6babc0e3a672 100644
--- a/drivers/iommu/iommu-uclass.c
+++ b/drivers/iommu/iommu-uclass.c
@@ -77,6 +77,7 @@ int dev_iommu_enable(struct udevice *dev)
 {
 	struct ofnode_phandle_args args;
 	struct udevice *dev_iommu;
+	const struct iommu_ops *ops;
 	int i, count, ret = 0;
 
 	count = dev_count_phandle_with_args(dev, "iommus",
@@ -98,6 +99,16 @@ int dev_iommu_enable(struct udevice *dev)
 			return ret;
 		}
 		dev->iommu = dev_iommu;
+
+		if (dev->parent && dev->parent->iommu == dev_iommu)
+			continue;
+
+		ops = device_get_ops(dev->iommu);
+		if (ops && ops->connect) {
+			ret = ops->connect(dev);
+			if (ret)
+				return ret;
+		}
 	}
 
 #if CONFIG_IS_ENABLED(PCI)
diff --git a/include/iommu.h b/include/iommu.h
index cf9719c5e91c..b8ba0b8e7077 100644
--- a/include/iommu.h
+++ b/include/iommu.h
@@ -4,6 +4,15 @@
 struct udevice;
 
 struct iommu_ops {
+	/**
+	 * init() - Connect a device to it's IOMMU, called before probe()
+	 * The iommu device can be fetched through dev->iommu
+	 *
+	 * @iommu_dev:	IOMMU device
+	 * @dev:	Device to connect
+	 * @return 0 if OK, -errno on error
+	 */
+	int (*connect)(struct udevice *dev);
 	/**
 	 * map() - map DMA memory
 	 *

-- 
2.42.1