u-boot/board/ti/common/cape_detect.c
Kory Maincent 8c1d443206 ti/common: add support for extension_scan_board function
The BeagleBone platforms all use a common mechanism to discover and
identify extension boards (called "capes"): each extension board has an
I2C-connected EEPROM describing itself.

This patch implements a generic extension_scan_board() feature that can
be used by all BeagleBone platforms to read those I2C EEPROMs and fill
in the list of "extension" structures.

Following commits will enable this common logic on two BeagleBone
platforms.

Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
2021-05-13 13:09:09 -04:00

96 lines
2.6 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* (C) Copyright 2021
* Köry Maincent, Bootlin, <kory.maincent@bootlin.com>
*/
#include <common.h>
#include <malloc.h>
#include <i2c.h>
#include <extension_board.h>
#include "cape_detect.h"
static void sanitize_field(char *text, size_t size)
{
char *c = NULL;
for (c = text; c < text + (int)size; c++) {
if (*c == 0xFF)
*c = 0;
}
}
int extension_board_scan(struct list_head *extension_list)
{
struct extension *cape;
struct am335x_cape_eeprom_id eeprom_header;
int num_capes = 0;
int ret, i;
struct udevice *dev;
unsigned char addr;
char process_cape_part_number[17] = {'0'};
char process_cape_version[5] = {'0'};
uint8_t cursor = 0;
for (addr = CAPE_EEPROM_FIRST_ADDR; addr <= CAPE_EEPROM_LAST_ADDR; addr++) {
ret = i2c_get_chip_for_busnum(CONFIG_CAPE_EEPROM_BUS_NUM, addr, 1, &dev);
if (ret)
continue;
/* Move the read cursor to the beginning of the EEPROM */
dm_i2c_write(dev, 0, &cursor, 1);
ret = dm_i2c_read(dev, 0, (uint8_t *)&eeprom_header,
sizeof(struct am335x_cape_eeprom_id));
if (ret) {
printf("Cannot read i2c EEPROM\n");
continue;
}
if (eeprom_header.header != CAPE_MAGIC)
continue;
sanitize_field(eeprom_header.board_name, sizeof(eeprom_header.board_name));
sanitize_field(eeprom_header.version, sizeof(eeprom_header.version));
sanitize_field(eeprom_header.manufacturer, sizeof(eeprom_header.manufacturer));
sanitize_field(eeprom_header.part_number, sizeof(eeprom_header.part_number));
/* Process cape part_number */
memset(process_cape_part_number, 0, sizeof(process_cape_part_number));
strncpy(process_cape_part_number, eeprom_header.part_number, 16);
/* Some capes end with '.' */
for (i = 15; i >= 0; i--) {
if (process_cape_part_number[i] == '.')
process_cape_part_number[i] = '\0';
else
break;
}
/* Process cape version */
memset(process_cape_version, 0, sizeof(process_cape_version));
strncpy(process_cape_version, eeprom_header.version, 4);
for (i = 0; i < 4; i++) {
if (process_cape_version[i] == 0)
process_cape_version[i] = '0';
}
printf("BeagleBone Cape: %s (0x%x)\n", eeprom_header.board_name, addr);
cape = calloc(1, sizeof(struct extension));
if (!cape) {
printf("Error in memory allocation\n");
return num_capes;
}
snprintf(cape->overlay, sizeof(cape->overlay), "%s-%s.dtbo",
process_cape_part_number, process_cape_version);
strncpy(cape->name, eeprom_header.board_name, 32);
strncpy(cape->version, process_cape_version, 4);
strncpy(cape->owner, eeprom_header.manufacturer, 16);
list_add_tail(&cape->list, extension_list);
num_capes++;
}
return num_capes;
}