drivers: of: add automated assignment of reserved regions to client devices

This patch adds code for automated assignment of reserved memory regions
to struct device. reserved_mem->ops->device_init()/device_cleanup()
callbacks are called to perform reserved memory driver specific
initialization and cleanup

Based on previous code provided by Josh Cartwright <joshc@codeaurora.org>

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Grant Likely <grant.likely@linaro.org>

2 files changed, 77 insertions, 0 deletions

diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c
index 632aae861375..59fb12e84e6b 100644
--- a/drivers/of/of_reserved_mem.c
+++ b/drivers/of/of_reserved_mem.c
@@ -206,8 +206,16 @@ void __init fdt_init_reserved_mem(void)
         for (i = 0; i < reserved_mem_count; i++) {
                 struct reserved_mem *rmem = &reserved_mem[i];
                 unsigned long node = rmem->fdt_node;
+                int len;
+                const __be32 *prop;
                 int err = 0;
 
+                prop = of_get_flat_dt_prop(node, "phandle", &len);
+                if (!prop)
+                        prop = of_get_flat_dt_prop(node, "linux,phandle", &len);
+                if (prop)
+                        rmem->phandle = of_read_number(prop, len/4);
+
                 if (rmem->size == 0)
                         err = __reserved_mem_alloc_size(node, rmem->name,
                                                  &rmem->base, &rmem->size);
@@ -215,3 +223,65 @@ void __init fdt_init_reserved_mem(void)
                         __reserved_mem_init_node(rmem);
         }
 }
+
+static inline struct reserved_mem *__find_rmem(struct device_node *node)
+{
+        unsigned int i;
+
+        if (!node->phandle)
+                return NULL;
+
+        for (i = 0; i < reserved_mem_count; i++)
+                if (reserved_mem[i].phandle == node->phandle)
+                        return &reserved_mem[i];
+        return NULL;
+}
+
+/**
+ * of_reserved_mem_device_init() - assign reserved memory region to given device
+ *
+ * This function assign memory region pointed by "memory-region" device tree
+ * property to the given device.
+ */
+void of_reserved_mem_device_init(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);
+
+        if (!rmem || !rmem->ops || !rmem->ops->device_init)
+                return;
+
+        rmem->ops->device_init(rmem, dev);
+        dev_info(dev, "assigned reserved memory node %s\n", rmem->name);
+}
+
+/**
+ * of_reserved_mem_device_release() - release reserved memory device structures
+ *
+ * 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);
+
+        if (!rmem || !rmem->ops || !rmem->ops->device_release)
+                return;
+
+        rmem->ops->device_release(rmem, dev);
+}
diff --git a/include/linux/of_reserved_mem.h b/include/linux/of_reserved_mem.h
index 4669ddfdd5af..5b5efae09135 100644
--- a/include/linux/of_reserved_mem.h
+++ b/include/linux/of_reserved_mem.h
@@ -8,6 +8,7 @@ struct reserved_mem_ops;
 struct reserved_mem {
         const char                      *name;
         unsigned long                   fdt_node;
+        unsigned long                   phandle;
         const struct reserved_mem_ops   *ops;
         phys_addr_t                     base;
         phys_addr_t                     size;
@@ -27,10 +28,16 @@ typedef int (*reservedmem_of_init_fn)(struct reserved_mem *rmem);
         _OF_DECLARE(reservedmem, name, compat, init, reservedmem_of_init_fn)
 
 #ifdef CONFIG_OF_RESERVED_MEM
+void of_reserved_mem_device_init(struct device *dev);
+void of_reserved_mem_device_release(struct device *dev);
+
 void fdt_init_reserved_mem(void);
 void fdt_reserved_mem_save_node(unsigned long node, const char *uname,
                                phys_addr_t base, phys_addr_t size);
 #else
+static inline void of_reserved_mem_device_init(struct device *dev) { }
+static inline void of_reserved_mem_device_release(struct device *pdev) { }
+
 static inline void fdt_init_reserved_mem(void) { }
 static inline void fdt_reserved_mem_save_node(unsigned long node,
                 const char *uname, phys_addr_t base, phys_addr_t size) { }