dm: blk: Add a generic function for block device commands

Most block devices provide a command (e.g. 'sata', 'scsi', 'ide') and
these commands generally do the same thing. This makes it harder to
maintain this code and keep it consistent.

We now have a block device interface which is either implemented by driver
model (when CONFIG_BLK is enabled) or with a legacy interface. Therefore
it is possible to handle most of what these commands do with generic code.

Add a new generic function to process block-device commands using the
interface type and the current device number for that type.

Signed-off-by: Simon Glass <sjg@chromium.org>

cmd/Makefile

@@ -15,6 +15,7 @@ obj-y += version.o
 # command
 obj-$(CONFIG_CMD_AES) += aes.o
 obj-$(CONFIG_CMD_ARMFLASH) += armflash.o
+obj-y += blk_common.o
 obj-$(CONFIG_SOURCE) += source.o
 obj-$(CONFIG_CMD_SOURCE) += source.o
 obj-$(CONFIG_CMD_BDI) += bdinfo.o

cmd/blk_common.c

@@ -0,0 +1,104 @@
+/*
+ * Handling of common block commands
+ *
+ * Copyright (c) 2017 Google, Inc
+ *
+ * (C) Copyright 2000-2011
+ * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <blk.h>
+
+#ifdef HAVE_BLOCK_DEVICE
+int blk_common_cmd(int argc, char * const argv[], enum if_type if_type,
+		   int *cur_devnump)
+{
+	const char *if_name = blk_get_if_type_name(if_type);
+
+	switch (argc) {
+	case 0:
+	case 1:
+		return CMD_RET_USAGE;
+	case 2:
+		if (strncmp(argv[1], "inf", 3) == 0) {
+			blk_list_devices(if_type);
+			return 0;
+		} else if (strncmp(argv[1], "dev", 3) == 0) {
+			if (blk_print_device_num(if_type, *cur_devnump)) {
+				printf("\nno %s devices available\n", if_name);
+				return CMD_RET_FAILURE;
+			}
+			return 0;
+		} else if (strncmp(argv[1], "part", 4) == 0) {
+			if (blk_list_part(if_type))
+				printf("\nno %s devices available\n", if_name);
+			return 0;
+		}
+		return CMD_RET_USAGE;
+	case 3:
+		if (strncmp(argv[1], "dev", 3) == 0) {
+			int dev = (int)simple_strtoul(argv[2], NULL, 10);
+
+			if (!blk_show_device(if_type, dev)) {
+				*cur_devnump = dev;
+				printf("... is now current device\n");
+			} else {
+				return CMD_RET_FAILURE;
+			}
+			return 0;
+		} else if (strncmp(argv[1], "part", 4) == 0) {
+			int dev = (int)simple_strtoul(argv[2], NULL, 10);
+
+			if (blk_print_part_devnum(if_type, dev)) {
+				printf("\n%s device %d not available\n",
+				       if_name, dev);
+				return CMD_RET_FAILURE;
+			}
+			return 0;
+		}
+		return CMD_RET_USAGE;
+
+	default: /* at least 4 args */
+		if (strcmp(argv[1], "read") == 0) {
+			ulong addr = simple_strtoul(argv[2], NULL, 16);
+			lbaint_t blk = simple_strtoul(argv[3], NULL, 16);
+			ulong cnt = simple_strtoul(argv[4], NULL, 16);
+			ulong n;
+
+			printf("\n%s read: device %d block # %lld, count %ld ... ",
+			       if_name, *cur_devnump, (unsigned long long)blk,
+			       cnt);
+
+			n = blk_read_devnum(if_type, *cur_devnump, blk, cnt,
+					    (ulong *)addr);
+
+			printf("%ld blocks read: %s\n", n,
+			       n == cnt ? "OK" : "ERROR");
+			return n == cnt ? 0 : 1;
+		} else if (strcmp(argv[1], "write") == 0) {
+			ulong addr = simple_strtoul(argv[2], NULL, 16);
+			lbaint_t blk = simple_strtoul(argv[3], NULL, 16);
+			ulong cnt = simple_strtoul(argv[4], NULL, 16);
+			ulong n;
+
+			printf("\n%s write: device %d block # %lld, count %ld ... ",
+			       if_name, *cur_devnump, (unsigned long long)blk,
+			       cnt);
+
+			n = blk_write_devnum(if_type, *cur_devnump, blk, cnt,
+					     (ulong *)addr);
+
+			printf("%ld blocks written: %s\n", n,
+			       n == cnt ? "OK" : "ERROR");
+			return n == cnt ? 0 : 1;
+		} else {
+			return CMD_RET_USAGE;
+		}
+
+		return 0;
+	}
+}
+#endif

include/blk.h

@@ -632,4 +632,16 @@ int blk_select_hwpart_devnum(enum if_type if_type, int devnum, int hwpart);
  */
 const char *blk_get_if_type_name(enum if_type if_type);
 
+/**
+ * blk_common_cmd() - handle common commands with block devices
+ *
+ * @args: Number of arguments to the command (argv[0] is the command itself)
+ * @argv: Command arguments
+ * @if_type: Interface type
+ * @cur_devnump: Current device number for this interface type
+ * @return 0 if OK, CMD_RET_ERROR on error
+ */
+int blk_common_cmd(int argc, char * const argv[], enum if_type if_type,
+		   int *cur_devnump);
+
 #endif