cmd: blkls: Add blkls command

Add a command to print a list of available block device drivers,
and for each, the list of known block devices.

Signed-off-by: Niel Fourie <lusus@denx.de>
Cc: Simon Glass <sjg@chromium.org>
Cc: Stefan Roese <sr@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Stefan Roese <sr@denx.de>

cmd/Kconfig

@@ -1088,6 +1088,13 @@ config CMD_LOADS
 	help
 	  Load an S-Record file over serial line
 
+config CMD_LSBLK
+	depends on BLK
+	bool "lsblk - list block drivers and devices"
+	help
+	  Print list of available block device drivers, and for each, the list
+	  of known block devices.
+
 config CMD_MMC
 	bool "mmc"
 	help

cmd/Makefile

@@ -84,6 +84,7 @@ obj-$(CONFIG_CMD_LED) += led.o
 obj-$(CONFIG_CMD_LICENSE) += license.o
 obj-y += load.o
 obj-$(CONFIG_CMD_LOG) += log.o
+obj-$(CONFIG_CMD_LSBLK) += lsblk.o
 obj-$(CONFIG_ID_EEPROM) += mac.o
 obj-$(CONFIG_CMD_MD5SUM) += md5sum.o
 obj-$(CONFIG_CMD_MEMORY) += mem.o

cmd/lsblk.c

@@ -0,0 +1,51 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2020
+ * Niel Fourie, DENX Software Engineering, lusus@denx.de.
+ */
+
+#include <common.h>
+#include <dm.h>
+
+static int do_lsblk(struct cmd_tbl *cmdtp, int flag, int argc, char * const argv[])
+{
+	struct driver *d = ll_entry_start(struct driver, driver);
+	const int n_ents = ll_entry_count(struct driver, driver);
+	struct driver *entry;
+	struct udevice *udev;
+	struct uclass *uc;
+	struct blk_desc *desc;
+	int ret, i;
+
+	ret = uclass_get(UCLASS_BLK, &uc);
+	if (ret) {
+		puts("Could not get BLK uclass.\n");
+		return CMD_RET_FAILURE;
+	}
+	puts("Block Driver          Devices\n");
+	puts("-----------------------------\n");
+	for (entry = d; entry < d + n_ents; entry++) {
+		if (entry->id != UCLASS_BLK)
+			continue;
+		i = 0;
+		printf("%-20.20s", entry->name);
+		uclass_foreach_dev(udev, uc) {
+			if (udev->driver != entry)
+				continue;
+			desc = dev_get_uclass_platdata(udev);
+			printf("%c %s %u", i ? ',' : ':',
+			       blk_get_if_type_name(desc->if_type),
+			       desc->devnum);
+			i++;
+		}
+		if (!i)
+			puts(": <none>");
+		puts("\n");
+	}
+
+	return CMD_RET_SUCCESS;
+}
+
+U_BOOT_CMD(lsblk, 1, 0, do_lsblk, "list block drivers and devices",
+	   "- display list of block device drivers and attached block devices"
+);

test/py/tests/test_lsblk.py

@@ -0,0 +1,13 @@
+# SPDX-License-Identifier: GPL-2.0+
+# Copyright (C) 2020
+# Niel Fourie, DENX Software Engineering, lusus@denx.de
+
+import pytest
+
+@pytest.mark.buildconfigspec('blk')
+@pytest.mark.buildconfigspec('cmd_lsblk')
+def test_lsblk(u_boot_console):
+    """Test that `lsblk` prints a result which includes `host`."""
+    output = u_boot_console.run_command('lsblk')
+    assert "Block Driver" in output
+    assert "sandbox_host_blk" in output