Add console command to access io space registers

Provide u-boot console functions to access IO space registers. A no
thrills implementation, accessing one register at a time.

For example:
    boot > iod 80
    0080: 00000094
    boot > iod.w 80
    0080: 0094
    boot > iod.b 80
    0080: 94
    boot > iow.b 0x80 12
    boot > iod 0x80
    0080: 00000012

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

common/Makefile

@@ -120,6 +120,7 @@ COBJS-$(CONFIG_LOGBUFFER) += cmd_log.o
 COBJS-$(CONFIG_ID_EEPROM) += cmd_mac.o
 COBJS-$(CONFIG_CMD_MD5SUM) += cmd_md5sum.o
 COBJS-$(CONFIG_CMD_MEMORY) += cmd_mem.o
+COBJS-$(CONFIG_CMD_IO) += cmd_io.o
 COBJS-$(CONFIG_CMD_MFSL) += cmd_mfsl.o
 COBJS-$(CONFIG_MII) += miiphyutil.o
 COBJS-$(CONFIG_CMD_MII) += miiphyutil.o

common/cmd_io.c

@@ -0,0 +1,93 @@
+/*
+ * Copyright (c) 2012 The Chromium OS Authors.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+/*
+ * IO space access commands.
+ */
+
+#include <common.h>
+#include <command.h>
+#include <asm/io.h>
+
+/*
+ * IO Display
+ *
+ * Syntax:
+ *	iod{.b, .w, .l} {addr}
+ */
+int do_io_iod(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[])
+{
+	ulong addr;
+	int size;
+
+	if (argc != 2)
+		return CMD_RET_USAGE;
+
+	size = cmd_get_data_size(argv[0], 4);
+	if (size < 0)
+		return 1;
+
+	addr = simple_strtoul(argv[1], NULL, 16);
+
+	printf("%04x: ", (u16) addr);
+
+	if (size == 4)
+		printf("%08x\n", inl(addr));
+	else if (size == 2)
+		printf("%04x\n", inw(addr));
+	else
+		printf("%02x\n", inb(addr));
+
+	return 0;
+}
+
+int do_io_iow(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[])
+{
+	ulong addr, size, val;
+
+	if (argc != 3)
+		return CMD_RET_USAGE;
+
+	size = cmd_get_data_size(argv[0], 4);
+	if (size < 0)
+		return 1;
+
+	addr = simple_strtoul(argv[1], NULL, 16);
+	val = simple_strtoul(argv[2], NULL, 16);
+
+	if (size == 4)
+		outl((u32) val, addr);
+	else if (size == 2)
+		outw((u16) val, addr);
+	else
+		outb((u8) val, addr);
+
+	return 0;
+}
+
+/**************************************************/
+U_BOOT_CMD(iod, 2, 0, do_io_iod,
+	   "IO space display", "[.b, .w, .l] address [# of objects]");
+
+U_BOOT_CMD(iow, 3, 0, do_io_iow,
+	   "IO space modify (auto-incrementing address)",
+	   "[.b, .w, .l] address");

include/config_cmd_all.h

@@ -48,6 +48,7 @@
 #define CONFIG_CMD_IMI		/* iminfo			*/
 #define CONFIG_CMD_IMLS		/* List all found images	*/
 #define CONFIG_CMD_IMMAP	/* IMMR dump support		*/
+#define CONFIG_CMD_IO		/* Access to X86 IO space	*/
 #define CONFIG_CMD_IRQ		/* irqinfo			*/
 #define CONFIG_CMD_ITEST	/* Integer (and string) test	*/
 #define CONFIG_CMD_JFFS2	/* JFFS2 Support		*/