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      1 // SPDX-License-Identifier: GPL-2.0+
      2 /*
      3  * (C) Copyright 2009-2016 CompuLab, Ltd.
      4  *
      5  * Authors: Nikita Kiryanov <nikita (at) compulab.co.il>
      6  *	    Igor Grinberg <grinberg (at) compulab.co.il>
      7  */
      8 
      9 #include <common.h>
     10 #include <linux/kernel.h>
     11 #include <eeprom_layout.h>
     12 #include <eeprom_field.h>
     13 
     14 #define NO_LAYOUT_FIELDS	"Unknown layout. Dumping raw data\n"
     15 
     16 struct eeprom_field layout_unknown[1] = {
     17 	{ NO_LAYOUT_FIELDS, 256, NULL, eeprom_field_print_bin,
     18 				       eeprom_field_update_bin },
     19 };
     20 
     21 /*
     22  * eeprom_layout_detect() - detect layout based on the contents of the data.
     23  * @data: Pointer to the data to be analyzed.
     24  *
     25  * Returns: the detected layout version.
     26  */
     27 __weak int eeprom_layout_detect(unsigned char *data)
     28 {
     29 	return LAYOUT_VERSION_UNRECOGNIZED;
     30 }
     31 
     32 /*
     33  * __eeprom_layout_assign() - set the layout fields
     34  * @layout:		A pointer to an existing struct layout.
     35  * @layout_version:	The version number of the desired layout
     36  */
     37 __weak void __eeprom_layout_assign(struct eeprom_layout *layout,
     38 				   int layout_version)
     39 {
     40 	layout->fields = layout_unknown;
     41 	layout->num_of_fields = ARRAY_SIZE(layout_unknown);
     42 }
     43 void eeprom_layout_assign(struct eeprom_layout *layout, int layout_version) \
     44 		__attribute__((weak, alias("__eeprom_layout_assign")));
     45 
     46 /*
     47  * eeprom_layout_print() - print the layout and the data which is assigned to it
     48  * @layout: A pointer to an existing struct layout.
     49  */
     50 static void eeprom_layout_print(const struct eeprom_layout *layout)
     51 {
     52 	int i;
     53 	struct eeprom_field *fields = layout->fields;
     54 
     55 	for (i = 0; i < layout->num_of_fields; i++)
     56 		fields[i].print(&fields[i]);
     57 }
     58 
     59 /*
     60  * eeprom_layout_update_field() - update a single field in the layout data.
     61  * @layout:	A pointer to an existing struct layout.
     62  * @field_name:	The name of the field to update.
     63  * @new_data:	The new field data (a string. Format depends on the field)
     64  *
     65  * Returns: 0 on success, negative error value on failure.
     66  */
     67 static int eeprom_layout_update_field(struct eeprom_layout *layout,
     68 				      char *field_name, char *new_data)
     69 {
     70 	int i, err;
     71 	struct eeprom_field *fields = layout->fields;
     72 
     73 	if (new_data == NULL)
     74 		return 0;
     75 
     76 	if (field_name == NULL)
     77 		return -1;
     78 
     79 	for (i = 0; i < layout->num_of_fields; i++) {
     80 		if (fields[i].name == RESERVED_FIELDS ||
     81 		    strcmp(fields[i].name, field_name))
     82 			continue;
     83 
     84 		err = fields[i].update(&fields[i], new_data);
     85 		if (err)
     86 			printf("Invalid data for field %s\n", field_name);
     87 
     88 		return err;
     89 	}
     90 
     91 	printf("No such field '%s'\n", field_name);
     92 
     93 	return -1;
     94 }
     95 
     96 /*
     97  * eeprom_layout_setup() - setup layout struct with the layout data and
     98  *			   metadata as dictated by layout_version
     99  * @layout:	A pointer to an existing struct layout.
    100  * @buf:	A buffer initialized with the eeprom data.
    101  * @buf_size:	Size of buf in bytes.
    102  * @layout version: The version number of the layout.
    103  */
    104 void eeprom_layout_setup(struct eeprom_layout *layout, unsigned char *buf,
    105 			 unsigned int buf_size, int layout_version)
    106 {
    107 	int i;
    108 
    109 	if (layout_version == LAYOUT_VERSION_AUTODETECT)
    110 		layout->layout_version = eeprom_layout_detect(buf);
    111 	else
    112 		layout->layout_version = layout_version;
    113 
    114 	eeprom_layout_assign(layout, layout_version);
    115 	layout->data = buf;
    116 	for (i = 0; i < layout->num_of_fields; i++) {
    117 		layout->fields[i].buf = buf;
    118 		buf += layout->fields[i].size;
    119 	}
    120 
    121 	layout->data_size = buf_size;
    122 	layout->print = eeprom_layout_print;
    123 	layout->update = eeprom_layout_update_field;
    124 }
    125