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>

3 files changed, 378 insertions, 0 deletions

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;
+}