[U-Boot] [PATCH v3 02/35] dm: core: Add dev_read_resource() to read device resources

[Simon Glass]

Add a function which reads resources from a device, such as the device
hardware address. This uses the "reg" property in the device.

Unlike other functions there is little sense in inlining this when
livetree is not being used because it has some logic in it and this would
just bloat the code size.

Signed-off-by: Simon Glass <sjg at chromium.org>
---

Changes in v3:
- Add new patch to add dev_read_resource()

Changes in v2: None

 drivers/core/Makefile     |  2 +-
 drivers/core/read_extra.c | 37 +++++++++++++++++++++++++++++++++++++
 include/dm/read.h         | 12 ++++++++++++
 3 files changed, 50 insertions(+), 1 deletion(-)
 create mode 100644 drivers/core/read_extra.c

diff --git a/drivers/core/Makefile b/drivers/core/Makefile
index 435cf98ae1..fd2d4de0c8 100644
--- a/drivers/core/Makefile
+++ b/drivers/core/Makefile
@@ -15,4 +15,4 @@ obj-$(CONFIG_OF_LIVE) += of_access.o of_addr.o
 ifndef CONFIG_DM_DEV_READ_INLINE
 obj-$(CONFIG_OF_CONTROL) += read.o
 endif
-obj-$(CONFIG_OF_CONTROL) += of_extra.o ofnode.o
+obj-$(CONFIG_OF_CONTROL) += of_extra.o ofnode.o read_extra.o
diff --git a/drivers/core/read_extra.c b/drivers/core/read_extra.c
new file mode 100644
index 0000000000..a6d2f342d9
--- /dev/null
+++ b/drivers/core/read_extra.c
@@ -0,0 +1,37 @@
+/*
+ * Copyright (c) 2017 Google, Inc
+ * Written by Simon Glass <sjg at chromium.org>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <dm/of_addr.h>
+#include <dm/read.h>
+#include <linux/ioport.h>
+
+int dev_read_resource(struct udevice *dev, uint index, struct resource *res)
+{
+	ofnode node = dev_ofnode(dev);
+
+#ifdef CONFIG_OF_LIVE
+	if (ofnode_is_np(node)) {
+		return of_address_to_resource(ofnode_to_np(node), index, res);
+	} else
+#endif
+		{
+		struct fdt_resource fres;
+		int ret;
+
+		ret = fdt_get_resource(gd->fdt_blob, ofnode_to_offset(node),
+				       "reg", index, &fres);
+		if (ret < 0)
+			return -EINVAL;
+		memset(res, '\0', sizeof(*res));
+		res->start = fres.start;
+		res->end = fres.end;
+
+		return 0;
+	}
+}
diff --git a/include/dm/read.h b/include/dm/read.h
index 8c9846eaf2..65d5d1f357 100644
--- a/include/dm/read.h
+++ b/include/dm/read.h
@@ -14,6 +14,8 @@
 #include <dm/ofnode.h>
 #include <dm/uclass.h>
 
+struct resource;
+
 #if CONFIG_IS_ENABLED(OF_LIVE)
 static inline const struct device_node *dev_np(struct udevice *dev)
 {
@@ -42,6 +44,16 @@ static inline bool dev_of_valid(struct udevice *dev)
 	return ofnode_valid(dev_ofnode(dev));
 }
 
+/**
+ * dev_read_resource() - obtain an indexed resource from a device.
+ *
+ * @dev: devuce to examine
+ * @index index of the resource to retrieve (0 = first)
+ * @res returns the resource
+ * @return 0 if ok, negative on error
+ */
+int dev_read_resource(struct udevice *dev, uint index, struct resource *res);
+
 #ifndef CONFIG_DM_DEV_READ_INLINE
 /**
  * dev_read_u32_default() - read a 32-bit integer from a device's DT property
-- 
2.13.1.508.gb3defc5cc-goog