Merge tag 'samsung-drivers-exynos-mfc-4.8-2' of git://git.kernel.org/pub/scm/linux...

[cascardo/linux.git] / drivers / of / of_reserved_mem.c

diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c
index 2166482..3cf129f 100644 (file)
--- a/drivers/of/of_reserved_mem.c
+++ b/drivers/of/of_reserved_mem.c
@@ -21,6 +21,7 @@
 #include <linux/sizes.h>
 #include <linux/of_reserved_mem.h>
 #include <linux/sort.h>
+#include <linux/slab.h>
 
 #define MAX_RESERVED_REGIONS   16
 static struct reserved_mem reserved_mem[MAX_RESERVED_REGIONS];
@@ -296,53 +297,95 @@ static inline struct reserved_mem *__find_rmem(struct device_node *node)
        return NULL;
 }
 
+struct rmem_assigned_device {
+       struct device *dev;
+       struct reserved_mem *rmem;
+       struct list_head list;
+};
+
+static LIST_HEAD(of_rmem_assigned_device_list);
+static DEFINE_MUTEX(of_rmem_assigned_device_mutex);
+
 /**
- * of_reserved_mem_device_init() - assign reserved memory region to given device
+ * of_reserved_mem_device_init_by_idx() - assign reserved memory region to
+ *                                       given device
+ * @dev:       Pointer to the device to configure
+ * @np:                Pointer to the device_node with 'reserved-memory' property
+ * @idx:       Index of selected region
  *
- * This function assign memory region pointed by "memory-region" device tree
- * property to the given device.
+ * This function assigns respective DMA-mapping operations based on reserved
+ * memory region specified by 'memory-region' property in @np node to the @dev
+ * device. When driver needs to use more than one reserved memory region, it
+ * should allocate child devices and initialize regions by name for each of
+ * child device.
+ *
+ * Returns error code or zero on success.
  */
-int of_reserved_mem_device_init(struct device *dev)
+int of_reserved_mem_device_init_by_idx(struct device *dev,
+                                      struct device_node *np, int idx)
 {
+       struct rmem_assigned_device *rd;
+       struct device_node *target;
        struct reserved_mem *rmem;
-       struct device_node *np;
        int ret;
 
-       np = of_parse_phandle(dev->of_node, "memory-region", 0);
-       if (!np)
-               return -ENODEV;
+       if (!np || !dev)
+               return -EINVAL;
+
+       target = of_parse_phandle(np, "memory-region", idx);
+       if (!target)
+               return -EINVAL;
 
-       rmem = __find_rmem(np);
-       of_node_put(np);
+       rmem = __find_rmem(target);
+       of_node_put(target);
 
        if (!rmem || !rmem->ops || !rmem->ops->device_init)
                return -EINVAL;
 
+       rd = kmalloc(sizeof(struct rmem_assigned_device), GFP_KERNEL);
+       if (!rd)
+               return -ENOMEM;
+
        ret = rmem->ops->device_init(rmem, dev);
-       if (ret == 0)
+       if (ret == 0) {
+               rd->dev = dev;
+               rd->rmem = rmem;
+
+               mutex_lock(&of_rmem_assigned_device_mutex);
+               list_add(&rd->list, &of_rmem_assigned_device_list);
+               mutex_unlock(&of_rmem_assigned_device_mutex);
+
                dev_info(dev, "assigned reserved memory node %s\n", rmem->name);
+       } else {
+               kfree(rd);
+       }
 
        return ret;
 }
-EXPORT_SYMBOL_GPL(of_reserved_mem_device_init);
+EXPORT_SYMBOL_GPL(of_reserved_mem_device_init_by_idx);
 
 /**
  * of_reserved_mem_device_release() - release reserved memory device structures
+ * @dev:       Pointer to the device to deconfigure
  *
  * This function releases structures allocated for memory region handling for
  * the given device.
  */
 void of_reserved_mem_device_release(struct device *dev)
 {
-       struct reserved_mem *rmem;
-       struct device_node *np;
-
-       np = of_parse_phandle(dev->of_node, "memory-region", 0);
-       if (!np)
-               return;
-
-       rmem = __find_rmem(np);
-       of_node_put(np);
+       struct rmem_assigned_device *rd;
+       struct reserved_mem *rmem = NULL;
+
+       mutex_lock(&of_rmem_assigned_device_mutex);
+       list_for_each_entry(rd, &of_rmem_assigned_device_list, list) {
+               if (rd->dev == dev) {
+                       rmem = rd->rmem;
+                       list_del(&rd->list);
+                       kfree(rd);
+                       break;
+               }
+       }
+       mutex_unlock(&of_rmem_assigned_device_mutex);
 
        if (!rmem || !rmem->ops || !rmem->ops->device_release)
                return;