[PATCH v3] cmd: Add command to dump drivers and compatible strings

[Sean Anderson]

This adds a subcommand to dm to dump out what drivers are installed, and their
compatible strings. I have found this useful in ensuring that I have the correct
drivers compiled, and that I have put in the correct compatible strings.

Signed-off-by: Sean Anderson <seanga2 at gmail.com>
Reviewed-by: Bin Meng <bmeng.cn at gmail.com>
Tested-by: Bin Meng <bmeng.cn at gmail.com>

---

Changes in v3:
- Add python test

Changes in v2:
- Check if entry->of_match is NULL before accessing it
- Remove trailing newline in help message

 cmd/dm.c                 | 12 +++++++++++-
 drivers/core/dump.c      | 20 ++++++++++++++++++++
 include/dm/util.h        |  3 +++
 test/py/tests/test_dm.py | 17 +++++++++++++++++
 4 files changed, 51 insertions(+), 1 deletion(-)
 create mode 100644 test/py/tests/test_dm.py

diff --git a/cmd/dm.c b/cmd/dm.c
index 7b271db0bb..7a90685f8b 100644
--- a/cmd/dm.c
+++ b/cmd/dm.c
@@ -40,10 +40,19 @@ static int do_dm_dump_devres(cmd_tbl_t *cmdtp, int flag, int argc,
 	return 0;
 }
 
+static int do_dm_dump_drivers(cmd_tbl_t *cmdtp, int flag, int argc,
+			      char * const argv[])
+{
+	dm_dump_drivers();
+
+	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, "", ""),
+	U_BOOT_CMD_MKENT(drivers, 1, 1, do_dm_dump_drivers, "", ""),
 };
 
 static __maybe_unused void dm_reloc(void)
@@ -84,5 +93,6 @@ U_BOOT_CMD(
 	"Driver model low level access",
 	"tree          Dump driver model tree ('*' = activated)\n"
 	"dm uclass        Dump list of instances for each uclass\n"
-	"dm devres        Dump list of device resources for each device"
+	"dm devres        Dump list of device resources for each device\n"
+	"dm drivers       Dump list of drivers and their compatible strings"
 );
diff --git a/drivers/core/dump.c b/drivers/core/dump.c
index 4704049aee..b5046398d4 100644
--- a/drivers/core/dump.c
+++ b/drivers/core/dump.c
@@ -96,3 +96,23 @@ void dm_dump_uclass(void)
 		puts("\n");
 	}
 }
+
+void dm_dump_drivers(void)
+{
+	struct driver *d = ll_entry_start(struct driver, driver);
+	const int n_ents = ll_entry_count(struct driver, driver);
+	struct driver *entry;
+	const struct udevice_id *match;
+
+	puts("Driver                Compatible\n");
+	puts("--------------------------------\n");
+	for (entry = d; entry < d + n_ents; entry++) {
+		for (match = entry->of_match;
+		     match && match->compatible; match++)
+			printf("%-20.20s  %s\n",
+			       match == entry->of_match ? entry->name : "",
+			       match->compatible);
+		if (match == entry->of_match)
+			printf("%-20.20s\n", entry->name);
+	}
+}
diff --git a/include/dm/util.h b/include/dm/util.h
index 348c2ace3c..0ccb3fbadf 100644
--- a/include/dm/util.h
+++ b/include/dm/util.h
@@ -39,6 +39,9 @@ static inline void dm_dump_devres(void)
 }
 #endif
 
+/* Dump out a list of drivers */
+void dm_dump_drivers(void);
+
 /**
  * Check if an of node should be or was bound before relocation.
  *
diff --git a/test/py/tests/test_dm.py b/test/py/tests/test_dm.py
new file mode 100644
index 0000000000..f6fbf8ba4c
--- /dev/null
+++ b/test/py/tests/test_dm.py
@@ -0,0 +1,17 @@
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (C) 2020 Sean Anderson
+
+import pytest
+
+ at pytest.mark.buildconfigspec('cmd_dm')
+def test_dm_drivers(u_boot_console):
+    """Test that each driver in `dm tree` is also listed in `dm drivers`."""
+    response = u_boot_console.run_command('dm tree')
+    driver_index = response.find('Driver')
+    assert driver_index != -1
+    drivers = (line[driver_index:].split()[0]
+               for line in response[:-1].split('\n')[2:])
+
+    response = u_boot_console.run_command('dm drivers')
+    for driver in drivers:
+        assert driver in response
-- 
2.25.0