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>

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.
 

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
  */

include/dm/util.h

@@ -39,4 +39,13 @@ void dm_dump_all(void);
 /* Dump out a list of uclasses and their devices */
 void dm_dump_uclass(void);
 
+#ifdef CONFIG_DEBUG_DEVRES
+/* Dump out a list of device resources */
+void dm_dump_devres(void);
+#else
+static inline void dm_dump_devres(void)
+{
+}
+#endif
+
 #endif

test/dm/cmd_dm.c

@@ -32,9 +32,18 @@ static int do_dm_dump_uclass(cmd_tbl_t *cmdtp, int flag, int argc,
 	return 0;
 }
 
+static int do_dm_dump_devres(cmd_tbl_t *cmdtp, int flag, int argc,
+			     char * const argv[])
+{
+	dm_dump_devres();
+
+	return 0;
+}
+
 static cmd_tbl_t test_commands[] = {
 	U_BOOT_CMD_MKENT(tree, 0, 1, do_dm_dump_all, "", ""),
 	U_BOOT_CMD_MKENT(uclass, 1, 1, do_dm_dump_uclass, "", ""),
+	U_BOOT_CMD_MKENT(devres, 1, 1, do_dm_dump_devres, "", ""),
 };
 
 static int do_dm(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
@@ -60,5 +69,6 @@ U_BOOT_CMD(
 	dm,	3,	1,	do_dm,
 	"Driver model low level access",
 	"tree         Dump driver model tree ('*' = activated)\n"
-	"dm uclass        Dump list of instances for each uclass"
+	"dm uclass        Dump list of instances for each uclass\n"
+	"dm devres        Dump list of device resources for each device"
 );