Add fuse API and commands

This can be useful for fuse-like hardware, OTP SoC options, etc.

Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>

common/Makefile

@@ -111,6 +111,7 @@ ifdef CONFIG_FPGA
 COBJS-$(CONFIG_CMD_FPGA) += cmd_fpga.o
 endif
 COBJS-$(CONFIG_CMD_FS_GENERIC) += cmd_fs.o
+COBJS-$(CONFIG_CMD_FUSE) += cmd_fuse.o
 COBJS-$(CONFIG_CMD_GETTIME) += cmd_gettime.o
 COBJS-$(CONFIG_CMD_GPIO) += cmd_gpio.o
 COBJS-$(CONFIG_CMD_I2C) += cmd_i2c.o

common/cmd_fuse.c

@@ -0,0 +1,168 @@
+/*
+ * (C) Copyright 2009-2013 ADVANSEE
+ * Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
+ *
+ * Based on the mpc512x iim code:
+ * Copyright 2008 Silicon Turnkey Express, Inc.
+ * Martha Marx <mmarx@silicontkx.com>
+ *
+ * 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
+ */
+
+#include <common.h>
+#include <command.h>
+#include <fuse.h>
+#include <asm/errno.h>
+
+static int strtou32(const char *str, unsigned int base, u32 *result)
+{
+	char *ep;
+
+	*result = simple_strtoul(str, &ep, base);
+	if (ep == str || *ep != '\0')
+		return -EINVAL;
+
+	return 0;
+}
+
+static int confirm_prog(void)
+{
+	puts("Warning: Programming fuses is an irreversible operation!\n"
+			"         This may brick your system.\n"
+			"         Use this command only if you are sure of "
+					"what you are doing!\n"
+			"\nReally perform this fuse programming? <y/N>\n");
+
+	if (getc() == 'y') {
+		int c;
+
+		putc('y');
+		c = getc();
+		putc('\n');
+		if (c == '\r')
+			return 1;
+	}
+
+	puts("Fuse programming aborted\n");
+	return 0;
+}
+
+static int do_fuse(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[])
+{
+	const char *op = argc >= 2 ? argv[1] : NULL;
+	int confirmed = argc >= 3 && !strcmp(argv[2], "-y");
+	u32 bank, word, cnt, val;
+	int ret, i;
+
+	argc -= 2 + confirmed;
+	argv += 2 + confirmed;
+
+	if (argc < 2 || strtou32(argv[0], 0, &bank) ||
+			strtou32(argv[1], 0, &word))
+		return CMD_RET_USAGE;
+
+	if (!strcmp(op, "read")) {
+		if (argc == 2)
+			cnt = 1;
+		else if (argc != 3 || strtou32(argv[2], 0, &cnt))
+			return CMD_RET_USAGE;
+
+		printf("Reading bank %u:\n", bank);
+		for (i = 0; i < cnt; i++, word++) {
+			if (!(i % 4))
+				printf("\nWord 0x%.8x:", word);
+
+			ret = fuse_read(bank, word, &val);
+			if (ret)
+				goto err;
+
+			printf(" %.8x", val);
+		}
+		putc('\n');
+	} else if (!strcmp(op, "sense")) {
+		if (argc == 2)
+			cnt = 1;
+		else if (argc != 3 || strtou32(argv[2], 0, &cnt))
+			return CMD_RET_USAGE;
+
+		printf("Sensing bank %u:\n", bank);
+		for (i = 0; i < cnt; i++, word++) {
+			if (!(i % 4))
+				printf("\nWord 0x%.8x:", word);
+
+			ret = fuse_sense(bank, word, &val);
+			if (ret)
+				goto err;
+
+			printf(" %.8x", val);
+		}
+		putc('\n');
+	} else if (!strcmp(op, "prog")) {
+		if (argc < 3)
+			return CMD_RET_USAGE;
+
+		for (i = 2; i < argc; i++, word++) {
+			if (strtou32(argv[i], 16, &val))
+				return CMD_RET_USAGE;
+
+			printf("Programming bank %u word 0x%.8x to 0x%.8x...\n",
+					bank, word, val);
+			if (!confirmed && !confirm_prog())
+				return CMD_RET_FAILURE;
+			ret = fuse_prog(bank, word, val);
+			if (ret)
+				goto err;
+		}
+	} else if (!strcmp(op, "override")) {
+		if (argc < 3)
+			return CMD_RET_USAGE;
+
+		for (i = 2; i < argc; i++, word++) {
+			if (strtou32(argv[i], 16, &val))
+				return CMD_RET_USAGE;
+
+			printf("Overriding bank %u word 0x%.8x with "
+					"0x%.8x...\n", bank, word, val);
+			ret = fuse_override(bank, word, val);
+			if (ret)
+				goto err;
+		}
+	} else {
+		return CMD_RET_USAGE;
+	}
+
+	return 0;
+
+err:
+	puts("ERROR\n");
+	return ret;
+}
+
+U_BOOT_CMD(
+	fuse, CONFIG_SYS_MAXARGS, 0, do_fuse,
+	"Fuse sub-system",
+	     "read <bank> <word> [<cnt>] - read 1 or 'cnt' fuse words,\n"
+	"    starting at 'word'\n"
+	"fuse sense <bank> <word> [<cnt>] - sense 1 or 'cnt' fuse words,\n"
+	"    starting at 'word'\n"
+	"fuse prog [-y] <bank> <word> <hexval> [<hexval>...] - program 1 or\n"
+	"    several fuse words, starting at 'word' (PERMANENT)\n"
+	"fuse override <bank> <word> <hexval> [<hexval>...] - override 1 or\n"
+	"    several fuse words, starting at 'word'"
+);