cmd: eeprom: add support for layout aware commands

Introduce the (optional) eeprom print and eeprom update commands.

These commands are eeprom layout aware:
* The eeprom print command prints the contents of the eeprom in a human
  readable way (eeprom layout fields, and data formatted to be fit for human
  consumption).
* The eeprom update command allows user to update eeprom fields by specifying
  the field name, and providing the new data in a human readable format (same
  format as displayed by the eeprom print command).
* Both commands can either auto detect the layout, or be told which layout to
  use.

New CONFIG options:
CONFIG_CMD_EEPROM_LAYOUT - enables commands.
CONFIG_EEPROM_LAYOUT_HELP_STRING - tells user what layout names are supported

Feature API:
__weak int parse_layout_version(char *str)
	- override to provide your own layout name parsing
__weak void __eeprom_layout_assign(struct eeprom_layout *layout, int layout_version);
	- override to setup the layout metadata based on the version
__weak int eeprom_layout_detect(unsigned char *data)
	- override to provide your own algorithm for detecting layout version
eeprom_field.c
	- contains various printing and updating functions for common types of
	  eeprom fields. Can be used for defining custom layouts.

Cc: Heiko Schocher <hs@denx.de>
Cc: Marek Vasut <marex@denx.de>
Cc: Simon Glass <sjg@chromium.org>
Cc: Igor Grinberg <grinberg@compulab.co.il>
Cc: Tom Rini <trini@konsulko.com>
Signed-off-by: Nikita Kiryanov <nikita@compulab.co.il>

7 files changed, 598 insertions, 1 deletions

diff --git a/README b/README
index 94e9943b04..6f4c09a3a1 100644
--- a/README
+++ b/README
@@ -1003,6 +1003,7 @@ The following options need to be configured:
 		CONFIG_CMD_ECHO		  echo arguments
 		CONFIG_CMD_EDITENV	  edit env variable
 		CONFIG_CMD_EEPROM	* EEPROM read/write support
+		CONFIG_CMD_EEPROM_LAYOUT* EEPROM layout aware commands
 		CONFIG_CMD_ELF		* bootelf, bootvx
 		CONFIG_CMD_ENV_CALLBACK	* display details about env callbacks
 		CONFIG_CMD_ENV_FLAGS	* display details about env flags
diff --git a/cmd/eeprom.c b/cmd/eeprom.c
index 208b4138c1..39ebee8dd9 100644
--- a/cmd/eeprom.c
+++ b/cmd/eeprom.c
@@ -207,6 +207,131 @@ int eeprom_write(unsigned dev_addr, unsigned offset,
 	return ret;
 }
 
+#ifdef CONFIG_CMD_EEPROM_LAYOUT
+#include <eeprom_layout.h>
+
+__weak int eeprom_parse_layout_version(char *str)
+{
+	return LAYOUT_VERSION_UNRECOGNIZED;
+}
+
+static unsigned char eeprom_buf[CONFIG_SYS_EEPROM_SIZE];
+
+#ifndef CONFIG_EEPROM_LAYOUT_HELP_STRING
+#define CONFIG_EEPROM_LAYOUT_HELP_STRING "<not defined>"
+#endif
+
+enum eeprom_action {
+	EEPROM_PRINT,
+	EEPROM_UPDATE,
+	EEPROM_ACTION_INVALID,
+};
+
+static enum eeprom_action parse_action(char *cmd)
+{
+	if (!strncmp(cmd, "print", 5))
+		return EEPROM_PRINT;
+	if (!strncmp(cmd, "update", 6))
+		return EEPROM_UPDATE;
+
+	return EEPROM_ACTION_INVALID;
+}
+
+static int parse_numeric_param(char *str)
+{
+	char *endptr;
+	int value = simple_strtol(str, &endptr, 16);
+
+	return (*endptr != '\0') ? -1 : value;
+}
+
+static int eeprom_execute_command(enum eeprom_action action, int i2c_bus,
+				  int i2c_addr, int layout_ver, char *key,
+				  char *value)
+{
+	int rcode;
+	struct eeprom_layout layout;
+
+	if (action == EEPROM_ACTION_INVALID)
+		return CMD_RET_USAGE;
+
+	eeprom_init(i2c_bus);
+	rcode = eeprom_read(i2c_addr, 0, eeprom_buf, CONFIG_SYS_EEPROM_SIZE);
+	if (rcode < 0)
+		return rcode;
+
+	eeprom_layout_setup(&layout, eeprom_buf, CONFIG_SYS_EEPROM_SIZE,
+			    layout_ver);
+
+	if (action == EEPROM_PRINT) {
+		layout.print(&layout);
+		return 0;
+	}
+
+	layout.update(&layout, key, value);
+
+	rcode = eeprom_write(i2c_addr, 0, layout.data, CONFIG_SYS_EEPROM_SIZE);
+
+	return rcode;
+}
+
+#define NEXT_PARAM(argc, index)	{ (argc)--; (index)++; }
+static int do_eeprom_layout(cmd_tbl_t *cmdtp, int flag, int argc,
+			    char * const argv[])
+{
+	int layout_ver = LAYOUT_VERSION_AUTODETECT;
+	enum eeprom_action action = EEPROM_ACTION_INVALID;
+	int i2c_bus = -1, i2c_addr = -1, index = 0;
+	char *field_name = "";
+	char *field_value = "";
+
+	if (argc <= 1)
+		return CMD_RET_USAGE;
+
+	NEXT_PARAM(argc, index); /* Skip program name */
+
+	action = parse_action(argv[index]);
+	NEXT_PARAM(argc, index);
+
+	if (argc <= 1)
+		return CMD_RET_USAGE;
+
+	if (!strcmp(argv[index], "-l")) {
+		NEXT_PARAM(argc, index);
+
+		layout_ver = eeprom_parse_layout_version(argv[index]);
+		NEXT_PARAM(argc, index);
+	}
+
+	if (argc <= 1)
+		return CMD_RET_USAGE;
+
+	i2c_bus = parse_numeric_param(argv[index]);
+	NEXT_PARAM(argc, index);
+
+	i2c_addr = parse_numeric_param(argv[index]);
+	NEXT_PARAM(argc, index);
+
+	if (action == EEPROM_PRINT)
+		goto done;
+
+	if (argc) {
+		field_name = argv[index];
+		NEXT_PARAM(argc, index);
+	}
+
+	if (argc) {
+		field_value = argv[index];
+		NEXT_PARAM(argc, index);
+	}
+
+done:
+	return eeprom_execute_command(action, i2c_bus, i2c_addr, layout_ver,
+			       field_name, field_value);
+}
+
+#endif
+
 static int do_eeprom(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 {
 	const char *const fmt =
@@ -216,6 +341,13 @@ static int do_eeprom(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 	ulong dev_addr, addr, off, cnt;
 	int bus_addr;
 
+#ifdef CONFIG_CMD_EEPROM_LAYOUT
+	if (argc >= 2) {
+		if (!strcmp(argv[1], "update") || !strcmp(argv[1], "print"))
+			return do_eeprom_layout(cmdtp, flag, argc, argv);
+	}
+#endif
+
 	switch (argc) {
 #ifdef CONFIG_SYS_DEF_EEPROM_ADDR
 	case 5:
@@ -261,9 +393,23 @@ static int do_eeprom(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 }
 
 U_BOOT_CMD(
-	eeprom,	7,	1,	do_eeprom,
+	eeprom,	8,	1,	do_eeprom,
 	"EEPROM sub-system",
 	"read  <bus> <devaddr> addr off cnt\n"
 	"eeprom write <bus> <devaddr> addr off cnt\n"
 	"       - read/write `cnt' bytes from `devaddr` EEPROM at offset `off'"
+#ifdef CONFIG_CMD_EEPROM_LAYOUT
+	"\n"
+	"eeprom print [-l <layout_version>] bus devaddr\n"
+	"       - Print layout fields and their data in human readable format\n"
+	"eeprom update [-l <layout_version>] bus devaddr <field_name> <field_value>\n"
+	"       - Update a specific eeprom field with new data.\n"
+	"         The new data must be written in the same human readable format as shown by the print command.\n"
+	"\n"
+	"LAYOUT VERSIONS\n"
+	"The -l option can be used to force the command to interpret the EEPROM data using the chosen layout.\n"
+	"If the -l option is omitted, the command will auto detect the layout based on the data in the EEPROM.\n"
+	"The values which can be provided with the -l option are:\n"
+	CONFIG_EEPROM_LAYOUT_HELP_STRING"\n"
+#endif
 )
diff --git a/common/Makefile b/common/Makefile
index f9b26b7bbe..0562d5cea4 100644
--- a/common/Makefile
+++ b/common/Makefile
@@ -156,6 +156,9 @@ obj-y += fb_nand.o
 endif
 endif
 
+ifdef CONFIG_CMD_EEPROM_LAYOUT
+obj-y += eeprom/eeprom_field.o eeprom/eeprom_layout.o
+endif
 # We always have this since drivers/ddr/fs/interactive.c needs it
 obj-$(CONFIG_CMDLINE) += cli_simple.o
 
diff --git a/common/eeprom/eeprom_field.c b/common/eeprom/eeprom_field.c
new file mode 100644
index 0000000000..7f095a64a2
--- /dev/null
+++ b/common/eeprom/eeprom_field.c
@@ -0,0 +1,250 @@
+/*
+ * (C) Copyright 2009-2016 CompuLab, Ltd.
+ *
+ * Authors: Nikita Kiryanov <nikita@compulab.co.il>
+ *	    Igor Grinberg <grinberg@compulab.co.il>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <linux/string.h>
+#include <eeprom_field.h>
+
+static void __eeprom_field_print_bin(const struct eeprom_field *field,
+				     char *delimiter, bool reverse)
+{
+	int i;
+	int from = reverse ? field->size - 1 : 0;
+	int to = reverse ? 0 : field->size - 1;
+
+	printf(PRINT_FIELD_SEGMENT, field->name);
+	for (i = from; i != to; reverse ? i-- : i++)
+		printf("%02x%s", field->buf[i], delimiter);
+
+	printf("%02x\n", field->buf[i]);
+}
+
+static int __eeprom_field_update_bin(struct eeprom_field *field,
+				     const char *value, bool reverse)
+{
+	int len = strlen(value);
+	int k, j, i = reverse ? len - 1 : 0;
+	unsigned char byte;
+	char *endptr;
+
+	/* each two characters in the string fit in one byte */
+	if (len > field->size * 2)
+		return -1;
+
+	memset(field->buf, 0, field->size);
+
+	/* i - string iterator, j - buf iterator */
+	for (j = 0; j < field->size; j++) {
+		byte = 0;
+		char tmp[3] = { 0, 0, 0 };
+
+		if ((reverse && i < 0) || (!reverse && i >= len))
+			break;
+
+		for (k = 0; k < 2; k++) {
+			if (reverse && i == 0) {
+				tmp[k] = value[i];
+				break;
+			}
+
+			tmp[k] = value[reverse ? i - 1 + k : i + k];
+		}
+
+		byte = simple_strtoul(tmp, &endptr, 0);
+		if (*endptr != '\0' || byte < 0)
+			return -1;
+
+		field->buf[j] = byte;
+		i = reverse ? i - 2 : i + 2;
+	}
+
+	return 0;
+}
+
+static int __eeprom_field_update_bin_delim(struct eeprom_field *field,
+					   char *value, char *delimiter)
+{
+	int count = 0;
+	int i, val;
+	const char *tmp = value;
+	char *tok;
+	char *endptr;
+
+	tmp = strstr(tmp, delimiter);
+	while (tmp != NULL) {
+		count++;
+		tmp++;
+		tmp = strstr(tmp, delimiter);
+	}
+
+	if (count > field->size)
+		return -1;
+
+	tok = strtok(value, delimiter);
+	for (i = 0; tok && i < field->size; i++) {
+		val = simple_strtoul(tok, &endptr, 0);
+		if (*endptr != '\0')
+			return -1;
+
+		/* here we assume that each tok is no more than byte long */
+		field->buf[i] = (unsigned char)val;
+		tok = strtok(NULL, delimiter);
+	}
+
+	return 0;
+}
+
+/**
+ * eeprom_field_print_bin() - print a field which contains binary data
+ *
+ * Treat the field data as simple binary data, and print it as two digit
+ * hexadecimal values.
+ * Sample output:
+ *      Field Name       0102030405060708090a
+ *
+ * @field:	an initialized field to print
+ */
+void eeprom_field_print_bin(const struct eeprom_field *field)
+{
+	__eeprom_field_print_bin(field, "", false);
+}
+
+/**
+ * eeprom_field_update_bin() - Update field with new data in binary form
+ *
+ * @field:	an initialized field
+ * @value:	a string of values (i.e. "10b234a")
+ */
+int eeprom_field_update_bin(struct eeprom_field *field, char *value)
+{
+	return __eeprom_field_update_bin(field, value, false);
+}
+
+/**
+ * eeprom_field_update_reserved() - Update reserved field with new data in
+ *				    binary form
+ *
+ * @field:	an initialized field
+ * @value:	a space delimited string of byte values (i.e. "1 02 3 0x4")
+ */
+int eeprom_field_update_reserved(struct eeprom_field *field, char *value)
+{
+	return __eeprom_field_update_bin_delim(field, value, " ");
+}
+
+/**
+ * eeprom_field_print_bin_rev() - print a field which contains binary data in
+ *				  reverse order
+ *
+ * Treat the field data as simple binary data, and print it in reverse order
+ * as two digit hexadecimal values.
+ *
+ * Data in field:
+ *                      0102030405060708090a
+ * Sample output:
+ *      Field Name      0a090807060504030201
+ *
+ * @field:	an initialized field to print
+ */
+void eeprom_field_print_bin_rev(const struct eeprom_field *field)
+{
+	__eeprom_field_print_bin(field, "", true);
+}
+
+/**
+ * eeprom_field_update_bin_rev() - Update field with new data in binary form,
+ *				   storing it in reverse
+ *
+ * This function takes a string of byte values, and stores them
+ * in the field in the reverse order. i.e. if the input string was "1234",
+ * "3412" will be written to the field.
+ *
+ * @field:	an initialized field
+ * @value:	a string of byte values
+ */
+int eeprom_field_update_bin_rev(struct eeprom_field *field, char *value)
+{
+	return __eeprom_field_update_bin(field, value, true);
+}
+
+/**
+ * eeprom_field_print_mac_addr() - print a field which contains a mac address
+ *
+ * Treat the field data as simple binary data, and print it formatted as a MAC
+ * address.
+ * Sample output:
+ *      Field Name     01:02:03:04:05:06
+ *
+ * @field:	an initialized field to print
+ */
+void eeprom_field_print_mac(const struct eeprom_field *field)
+{
+	__eeprom_field_print_bin(field, ":", false);
+}
+
+/**
+ * eeprom_field_update_mac() - Update a mac address field which contains binary
+ *			       data
+ *
+ * @field:	an initialized field
+ * @value:	a colon delimited string of byte values (i.e. "1:02:3:ff")
+ */
+int eeprom_field_update_mac(struct eeprom_field *field, char *value)
+{
+	return __eeprom_field_update_bin_delim(field, value, ":");
+}
+
+/**
+ * eeprom_field_print_ascii() - print a field which contains ASCII data
+ * @field:	an initialized field to print
+ */
+void eeprom_field_print_ascii(const struct eeprom_field *field)
+{
+	char format[8];
+
+	sprintf(format, "%%.%ds\n", field->size);
+	printf(PRINT_FIELD_SEGMENT, field->name);
+	printf(format, field->buf);
+}
+
+/**
+ * eeprom_field_update_ascii() - Update field with new data in ASCII form
+ * @field:	an initialized field
+ * @value:	the new string data
+ *
+ * Returns 0 on success, -1 of failure (new string too long).
+ */
+int eeprom_field_update_ascii(struct eeprom_field *field, char *value)
+{
+	if (strlen(value) >= field->size) {
+		printf("%s: new data too long\n", field->name);
+		return -1;
+	}
+
+	strncpy((char *)field->buf, value, field->size - 1);
+	field->buf[field->size - 1] = '\0';
+
+	return 0;
+}
+
+/**
+ * eeprom_field_print_reserved() - print the "Reserved fields" field
+ *
+ * Print a notice that the following field_size bytes are reserved.
+ *
+ * Sample output:
+ *      Reserved fields              (64 bytes)
+ *
+ * @field:	an initialized field to print
+ */
+void eeprom_field_print_reserved(const struct eeprom_field *field)
+{
+	printf(PRINT_FIELD_SEGMENT, "Reserved fields\t");
+	printf("(%d bytes)\n", field->size);
+}
diff --git a/common/eeprom/eeprom_layout.c b/common/eeprom/eeprom_layout.c
new file mode 100644
index 0000000000..c05923328a
--- /dev/null
+++ b/common/eeprom/eeprom_layout.c
@@ -0,0 +1,125 @@
+/*
+ * (C) Copyright 2009-2016 CompuLab, Ltd.
+ *
+ * Authors: Nikita Kiryanov <nikita@compulab.co.il>
+ *	    Igor Grinberg <grinberg@compulab.co.il>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <linux/kernel.h>
+#include <eeprom_layout.h>
+#include <eeprom_field.h>
+
+#define NO_LAYOUT_FIELDS	"Unknown layout. Dumping raw data\n"
+
+struct eeprom_field layout_unknown[1] = {
+	{ NO_LAYOUT_FIELDS, 256, NULL, eeprom_field_print_bin,
+				       eeprom_field_update_bin },
+};
+
+/*
+ * eeprom_layout_detect() - detect layout based on the contents of the data.
+ * @data: Pointer to the data to be analyzed.
+ *
+ * Returns: the detected layout version.
+ */
+__weak int eeprom_layout_detect(unsigned char *data)
+{
+	return LAYOUT_VERSION_UNRECOGNIZED;
+}
+
+/*
+ * __eeprom_layout_assign() - set the layout fields
+ * @layout:		A pointer to an existing struct layout.
+ * @layout_version:	The version number of the desired layout
+ */
+__weak void __eeprom_layout_assign(struct eeprom_layout *layout,
+				   int layout_version)
+{
+	layout->fields = layout_unknown;
+	layout->num_of_fields = ARRAY_SIZE(layout_unknown);
+}
+void eeprom_layout_assign(struct eeprom_layout *layout, int layout_version) \
+		__attribute__((weak, alias("__eeprom_layout_assign")));
+
+/*
+ * eeprom_layout_print() - print the layout and the data which is assigned to it
+ * @layout: A pointer to an existing struct layout.
+ */
+static void eeprom_layout_print(const struct eeprom_layout *layout)
+{
+	int i;
+	struct eeprom_field *fields = layout->fields;
+
+	for (i = 0; i < layout->num_of_fields; i++)
+		fields[i].print(&fields[i]);
+}
+
+/*
+ * eeprom_layout_update_field() - update a single field in the layout data.
+ * @layout:	A pointer to an existing struct layout.
+ * @field_name:	The name of the field to update.
+ * @new_data:	The new field data (a string. Format depends on the field)
+ *
+ * Returns: 0 on success, negative error value on failure.
+ */
+static int eeprom_layout_update_field(struct eeprom_layout *layout,
+				      char *field_name, char *new_data)
+{
+	int i, err;
+	struct eeprom_field *fields = layout->fields;
+
+	if (new_data == NULL)
+		return 0;
+
+	if (field_name == NULL)
+		return -1;
+
+	for (i = 0; i < layout->num_of_fields; i++) {
+		if (fields[i].name == RESERVED_FIELDS ||
+		    strcmp(fields[i].name, field_name))
+			continue;
+
+		err = fields[i].update(&fields[i], new_data);
+		if (err)
+			printf("Invalid data for field %s\n", field_name);
+
+		return err;
+	}
+
+	printf("No such field '%s'\n", field_name);
+
+	return -1;
+}
+
+/*
+ * eeprom_layout_setup() - setup layout struct with the layout data and
+ *			   metadata as dictated by layout_version
+ * @layout:	A pointer to an existing struct layout.
+ * @buf:	A buffer initialized with the eeprom data.
+ * @buf_size:	Size of buf in bytes.
+ * @layout version: The version number of the layout.
+ */
+void eeprom_layout_setup(struct eeprom_layout *layout, unsigned char *buf,
+			 unsigned int buf_size, int layout_version)
+{
+	int i;
+
+	if (layout_version == LAYOUT_VERSION_AUTODETECT)
+		layout->layout_version = eeprom_layout_detect(buf);
+	else
+		layout->layout_version = layout_version;
+
+	eeprom_layout_assign(layout, layout_version);
+	layout->data = buf;
+	for (i = 0; i < layout->num_of_fields; i++) {
+		layout->fields[i].buf = buf;
+		buf += layout->fields[i].size;
+	}
+
+	layout->data_size = buf_size;
+	layout->print = eeprom_layout_print;
+	layout->update = eeprom_layout_update_field;
+}
diff --git a/include/eeprom_field.h b/include/eeprom_field.h
new file mode 100644
index 0000000000..94e259ff73
--- /dev/null
+++ b/include/eeprom_field.h
@@ -0,0 +1,39 @@
+/*
+ * (C) Copyright 2009-2016 CompuLab, Ltd.
+ *
+ * Authors: Nikita Kiryanov <nikita@compulab.co.il>
+ *	    Igor Grinberg <grinberg@compulab.co.il>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef _FIELD_
+#define _FIELD_
+
+#define PRINT_FIELD_SEGMENT	"%-30s"
+
+struct eeprom_field {
+	char *name;
+	int size;
+	unsigned char *buf;
+
+	void (*print)(const struct eeprom_field *eeprom_field);
+	int (*update)(struct eeprom_field *eeprom_field, char *value);
+};
+
+void eeprom_field_print_bin(const struct eeprom_field *field);
+int eeprom_field_update_bin(struct eeprom_field *field, char *value);
+
+void eeprom_field_print_bin_rev(const struct eeprom_field *field);
+int eeprom_field_update_bin_rev(struct eeprom_field *field, char *value);
+
+void eeprom_field_print_mac(const struct eeprom_field *field);
+int eeprom_field_update_mac(struct eeprom_field *field, char *value);
+
+void eeprom_field_print_ascii(const struct eeprom_field *field);
+int eeprom_field_update_ascii(struct eeprom_field *field, char *value);
+
+void eeprom_field_print_reserved(const struct eeprom_field *field);
+int eeprom_field_update_reserved(struct eeprom_field *field, char *value);
+
+#endif
diff --git a/include/eeprom_layout.h b/include/eeprom_layout.h
new file mode 100644
index 0000000000..459b99d861
--- /dev/null
+++ b/include/eeprom_layout.h
@@ -0,0 +1,33 @@
+/*
+ * (C) Copyright 2009-2016 CompuLab, Ltd.
+ *
+ * Authors: Nikita Kiryanov <nikita@compulab.co.il>
+ *	    Igor Grinberg <grinberg@compulab.co.il>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef _LAYOUT_
+#define _LAYOUT_
+
+#define RESERVED_FIELDS			NULL
+#define LAYOUT_VERSION_UNRECOGNIZED	-1
+#define LAYOUT_VERSION_AUTODETECT	-2
+
+struct eeprom_layout {
+	struct eeprom_field *fields;
+	int num_of_fields;
+	int layout_version;
+	unsigned char *data;
+	int data_size;
+	void (*print)(const struct eeprom_layout *eeprom_layout);
+	int (*update)(struct eeprom_layout *eeprom_layout, char *field_name,
+		      char *new_data);
+};
+
+void eeprom_layout_setup(struct eeprom_layout *layout, unsigned char *buf,
+			 unsigned int buf_size, int layout_version);
+__weak void __eeprom_layout_assign(struct eeprom_layout *layout,
+				   int layout_version);
+
+#endif