[PATCH] cmd: dm: allow for selecting uclass and device

[AKASHI Takahiro]

The output from "dm tree" or "dm uclass" is a bit annoying
if the number of devices available on the system is huge.
(This is especially true on sandbox when I debug some DM code.)

With this patch, we can specify the uclass or the device
that we are interested in in order to limit the output.

For instance,

=> dm uclass usb
uclass 121: usb
0     usb at 1 @ 0bd008b0, seq 1

=> dm tree usb:usb at 1
 Class     Index  Probed  Driver                Name
-----------------------------------------------------------
 usb           0  [   ]   usb_sandbox           usb at 1
 usb_hub       0  [   ]   usb_hub               `-- hub
 usb_emul      0  [   ]   usb_sandbox_hub           `-- hub-emul
 usb_emul      1  [   ]   usb_sandbox_flash             |-- flash-stick at 0
 usb_emul      2  [   ]   usb_sandbox_flash             |-- flash-stick at 1
 usb_emul      3  [   ]   usb_sandbox_flash             |-- flash-stick at 2
 usb_emul      4  [   ]   usb_sandbox_keyb              `-- keyb at 3

Please note that, at "dm tree", the uclass name (usb) as well as
the device name (usb at 1) is required.

Signed-off-by: AKASHI Takahiro <takahiro.akashi at linaro.org>
---
 cmd/dm.c            | 30 ++++++++++++++++++++--------
 drivers/core/dump.c | 48 +++++++++++++++++++++++++++++++++++++++------
 include/dm/util.h   | 13 ++++++++----
 3 files changed, 73 insertions(+), 18 deletions(-)

diff --git a/cmd/dm.c b/cmd/dm.c
index 3263547cbec6..99268df2f87a 100644
--- a/cmd/dm.c
+++ b/cmd/dm.c
@@ -59,11 +59,20 @@ static int do_dm_dump_static_driver_info(struct cmd_tbl *cmdtp, int flag,
 static int do_dm_dump_tree(struct cmd_tbl *cmdtp, int flag, int argc,
 			   char *const argv[])
 {
-	bool sort;
+	bool sort = false;
+	char *device = NULL;
 
-	sort = argc > 1 && !strcmp(argv[1], "-s");
+	if (argc > 1) {
+		if (!strcmp(argv[1], "-s")) {
+			sort = true;
+			argc--;
+			argv++;
+		}
+		if (argc > 1)
+			device = argv[1];
+	}
 
-	dm_dump_tree(sort);
+	dm_dump_tree(device, sort);
 
 	return 0;
 }
@@ -71,7 +80,12 @@ static int do_dm_dump_tree(struct cmd_tbl *cmdtp, int flag, int argc,
 static int do_dm_dump_uclass(struct cmd_tbl *cmdtp, int flag, int argc,
 			     char *const argv[])
 {
-	dm_dump_uclass();
+	char *uclass = NULL;
+
+	if (argc > 1)
+		uclass = argv[1];
+
+	dm_dump_uclass(uclass);
 
 	return 0;
 }
@@ -91,8 +105,8 @@ static char dm_help_text[] =
 	"dm drivers       Dump list of drivers with uclass and instances\n"
 	DM_MEM_HELP
 	"dm static        Dump list of drivers with static platform data\n"
-	"dm tree [-s]     Dump tree of driver model devices (-s=sort)\n"
-	"dm uclass        Dump list of instances for each uclass"
+	"dm tree [-s][name] Dump tree of driver model devices (-s=sort)\n"
+	"dm uclass [name] Dump list of instances for each uclass"
 	;
 #endif
 
@@ -102,5 +116,5 @@ U_BOOT_CMD_WITH_SUBCMDS(dm, "Driver model low level access", dm_help_text,
 	U_BOOT_SUBCMD_MKENT(drivers, 1, 1, do_dm_dump_drivers),
 	DM_MEM
 	U_BOOT_SUBCMD_MKENT(static, 1, 1, do_dm_dump_static_driver_info),
-	U_BOOT_SUBCMD_MKENT(tree, 2, 1, do_dm_dump_tree),
-	U_BOOT_SUBCMD_MKENT(uclass, 1, 1, do_dm_dump_uclass));
+	U_BOOT_SUBCMD_MKENT(tree, 3, 1, do_dm_dump_tree),
+	U_BOOT_SUBCMD_MKENT(uclass, 2, 1, do_dm_dump_uclass));
diff --git a/drivers/core/dump.c b/drivers/core/dump.c
index 3e77832a3a00..855d6ca002b7 100644
--- a/drivers/core/dump.c
+++ b/drivers/core/dump.c
@@ -85,11 +85,35 @@ static void show_devices(struct udevice *dev, int depth, int last_flag,
 	}
 }
 
-void dm_dump_tree(bool sort)
+void dm_dump_tree(char *uclass, bool sort)
 {
 	struct udevice *root;
 
-	root = dm_root();
+	if (uclass) {
+		char *device;
+		enum uclass_id id;
+
+		device = strchr(uclass, ':');
+		if (!device) {
+			printf("name %s: invalid format\n", uclass);
+			return;
+		}
+		*device = '\0';
+		device++;
+
+		id = uclass_get_by_name(uclass);
+		if (id == UCLASS_INVALID) {
+			printf("uclass %s: not found\n", uclass);
+			return;
+		}
+		if (uclass_find_device_by_name(id, device, &root)) {
+			printf("device %s:%s: not found\n", uclass, device);
+			return;
+		}
+	} else {
+		root = dm_root();
+	}
+
 	if (root) {
 		int dev_count, uclasses;
 		struct udevice **devs = NULL;
@@ -127,13 +151,25 @@ static void dm_display_line(struct udevice *dev, int index)
 	puts("\n");
 }
 
-void dm_dump_uclass(void)
+void dm_dump_uclass(char *uclass)
 {
 	struct uclass *uc;
-	int ret;
-	int id;
+	enum uclass_id id;
+	int count, ret;
+
+	if (uclass) {
+		id = uclass_get_by_name(uclass);
+		if (id == UCLASS_INVALID) {
+			printf("uclass %s: not found\n", uclass);
+			return;
+		}
+		count = 1;
+	} else {
+		id = 0;
+		count = UCLASS_COUNT;
+	}
 
-	for (id = 0; id < UCLASS_COUNT; id++) {
+	for ( ; count; id++, count--) {
 		struct udevice *dev;
 		int i = 0;
 
diff --git a/include/dm/util.h b/include/dm/util.h
index 4bb49e9e8c01..ee1b34c103e3 100644
--- a/include/dm/util.h
+++ b/include/dm/util.h
@@ -27,14 +27,19 @@ struct list_head;
 int list_count_items(struct list_head *head);
 
 /**
- * Dump out a tree of all devices
+ * Dump out a tree of all devices starting @uclass
  *
+ * @uclass: uclass+device name
  * @sort: Sort by uclass name
  */
-void dm_dump_tree(bool sort);
+void dm_dump_tree(char *uclass, bool sort);
 
-/* Dump out a list of uclasses and their devices */
-void dm_dump_uclass(void);
+/*
+ * Dump out a list of uclasses and their devices
+ *
+ * @uclass: uclass name
+ */
+void dm_dump_uclass(char *uclass);
 
 #ifdef CONFIG_DEBUG_DEVRES
 /* Dump out a list of device resources */
-- 
2.34.1