devres: add debug command to dump device resources

This new command can dump all device resources associated to
each device.  The fields in every line shows:
  - The address of the resource
  - The size of the resource
  - The name of the release function
  - The stage in which the resource has been acquired (BIND/PROBE)

Currently, there is no driver using devres, but if such drivers are
implemented, the output of this command should look like this:

=> dm devres
- root_driver
- soc
- extbus
- serial@54006800
    bfb541e8 (8 byte) devm_kmalloc_release  BIND
    bfb54440 (4 byte) devm_kmalloc_release  PROBE
    bfb54460 (4 byte) devm_kmalloc_release  PROBE
- serial@54006900
    bfb54270 (8 byte) devm_kmalloc_release  BIND
- gpio@55000000
- i2c@58780000
    bfb5bce8 (12 byte) devm_kmalloc_release  PROBE
    bfb5bd10 (4 byte) devm_kmalloc_release  PROBE
- eeprom
    bfb54418 (12 byte) devm_kmalloc_release  BIND

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Simon Glass <sjg@chromium.org>

2 files changed, 31 insertions, 1 deletions

diff --git a/drivers/core/Kconfig b/drivers/core/Kconfig
index 8ae0072aa9..c82b5645cd 100644
--- a/drivers/core/Kconfig
+++ b/drivers/core/Kconfig
@@ -93,10 +93,11 @@ config DEVRES
 	  devm_kmalloc() to kmalloc(), etc.
 
 config DEBUG_DEVRES
-	bool "Managed device resources verbose debug messages"
+	bool "Managed device resources debugging functions"
 	depends on DEVRES
 	help
 	  If this option is enabled, devres debug messages are printed.
+	  Also, a function is available to dump a list of device resources.
 	  Select this if you are having a problem with devres or want to
 	  debug resource management for a managed device.
 
diff --git a/drivers/core/devres.c b/drivers/core/devres.c
index f235c1bcfd..605295bd14 100644
--- a/drivers/core/devres.c
+++ b/drivers/core/devres.c
@@ -13,6 +13,8 @@
 #include <linux/kernel.h>
 #include <linux/list.h>
 #include <dm/device.h>
+#include <dm/root.h>
+#include <dm/util.h>
 
 /**
  * struct devres - Bookkeeping info for managed device resource
@@ -195,6 +197,33 @@ void devres_release_all(struct udevice *dev)
 	release_nodes(dev, &dev->devres_head, false);
 }
 
+#ifdef CONFIG_DEBUG_DEVRES
+static void dump_resources(struct udevice *dev, int depth)
+{
+	struct devres *dr;
+	struct udevice *child;
+
+	printf("- %s\n", dev->name);
+
+	list_for_each_entry(dr, &dev->devres_head, entry)
+		printf("    %p (%lu byte) %s  %s\n", dr,
+		       (unsigned long)dr->size, dr->name,
+		       dr->probe ? "PROBE" : "BIND");
+
+	list_for_each_entry(child, &dev->child_head, sibling_node)
+		dump_resources(child, depth + 1);
+}
+
+void dm_dump_devres(void)
+{
+	struct udevice *root;
+
+	root = dm_root();
+	if (root)
+		dump_resources(root, 0);
+}
+#endif
+
 /*
  * Managed kmalloc/kfree
  */