[PATCH 5/8] drivers: platform: Configure dma operations at probe time

[Sricharan R <sricharan-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>]

Configuring DMA ops at probe time will allow deferring device probe when
the IOMMU isn't available yet.

Signed-off-by: Sricharan R <sricharan-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
---
 drivers/base/dd.c           | 11 +++++++++++
 drivers/base/dma-mapping.c  | 11 +++++++++++
 include/linux/dma-mapping.h |  3 +++
 3 files changed, 25 insertions(+)

diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index 16688f5..b9978af 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -19,6 +19,7 @@
 
 #include <linux/device.h>
 #include <linux/delay.h>
+#include <linux/dma-mapping.h>
 #include <linux/module.h>
 #include <linux/kthread.h>
 #include <linux/wait.h>
@@ -353,6 +354,10 @@ static int really_probe(struct device *dev, struct device_driver *drv)
 	if (ret)
 		goto pinctrl_bind_failed;
 
+	ret = dma_configure_ops(dev);
+	if (ret)
+		goto dma_failed;
+
 	if (driver_sysfs_add(dev)) {
 		printk(KERN_ERR "%s: driver_sysfs_add(%s) failed\n",
 			__func__, dev_name(dev));
@@ -394,7 +399,10 @@ static int really_probe(struct device *dev, struct device_driver *drv)
 		 drv->bus->name, __func__, dev_name(dev), drv->name);
 	goto done;
 
+
 probe_failed:
+	dma_deconfigure(dev);
+dma_failed:
 	if (dev->bus)
 		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
 					     BUS_NOTIFY_DRIVER_NOT_BOUND, dev);
@@ -780,6 +788,9 @@ static void __device_release_driver(struct device *dev)
 			dev->bus->remove(dev);
 		else if (drv->remove)
 			drv->remove(dev);
+
+		dma_deconfigure(dev);
+
 		devres_release_all(dev);
 		dev->driver = NULL;
 		dev_set_drvdata(dev, NULL);
diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
index d799662..ccc1c6e 100644
--- a/drivers/base/dma-mapping.c
+++ b/drivers/base/dma-mapping.c
@@ -10,6 +10,7 @@
 #include <linux/dma-mapping.h>
 #include <linux/export.h>
 #include <linux/gfp.h>
+#include <linux/of_device.h>
 #include <linux/slab.h>
 #include <linux/vmalloc.h>
 
@@ -166,6 +167,16 @@ void dmam_free_noncoherent(struct device *dev, size_t size, void *vaddr,
 }
 EXPORT_SYMBOL(dmam_free_noncoherent);
 
+int dma_configure_ops(struct device *dev)
+{
+	return of_dma_configure_ops(dev, dev->of_node);
+}
+
+void dma_deconfigure(struct device *dev)
+{
+	of_dma_deconfigure(dev);
+}
+
 #ifdef CONFIG_HAVE_GENERIC_DMA_COHERENT
 
 static void dmam_coherent_decl_release(struct device *dev, void *res)
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index 71c1b21..a49aac9 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -613,6 +613,9 @@ dma_mark_declared_memory_occupied(struct device *dev,
 }
 #endif /* CONFIG_HAVE_GENERIC_DMA_COHERENT */
 
+int dma_configure_ops(struct device *dev);
+void dma_deconfigure(struct device *dev);
+
 /*
  * Managed DMA API
  */
-- 
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