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// SPDX-License-Identifier: GPL-2.0-or-later
// SPDX-FileCopyrightText: 2023 John Watts <contact@jookia.org>
#include <common.h>
#include <deep-probe.h>
#include <fs.h>
#include <libfile.h>
#include <net.h>
struct novena_eeprom {
uint8_t signature[6]; /* 'Novena' */
uint8_t version; /* 1 or 2, not checked */
uint8_t page_size; /* v2 only: EEPROM read/write page */
uint32_t serial; /* 32-bit serial number */
uint8_t mac[6]; /* Gigabit MAC address */
uint16_t features; /* features */
/* ... extra fields omitted ... */
} __packed;
static void power_on_audio_codec(void)
{
int rc = of_devices_ensure_probed_by_name("regulator-audio-codec");
if (rc < 0)
pr_err("Unable to power on audio codec: %s\n", strerror(-rc));
}
static struct novena_eeprom *novena_read_eeprom(void)
{
size_t read;
loff_t max = sizeof(struct novena_eeprom);
void *eeprom;
int rc;
/*
* When powered off the audio codec pulls down the EEPROM's I2C line.
* Power it on so we can actually read data.
*/
power_on_audio_codec();
rc = of_device_ensure_probed_by_alias("eeprom0");
if (rc < 0) {
pr_err("Unable to probe eeprom0: %s\n", strerror(-rc));
return NULL;
}
rc = read_file_2("/dev/eeprom0", &read, &eeprom, max);
if (rc < 0 && rc != -EFBIG) {
pr_err("Unable to read Novena EEPROM: %s\n", strerror(-rc));
return NULL;
} else if (read != max) {
pr_err("Short read from Novena EEPROM?\n");
free(eeprom);
return NULL;
}
return eeprom;
}
static bool novena_check_eeprom(struct novena_eeprom *eeprom)
{
char *sig = eeprom->signature;
size_t size = sizeof(eeprom->signature);
if (memcmp("Novena", sig, size) != 0) {
pr_err("Unknown Novena EEPROM signature\n");
return false;
}
return true;
}
static void novena_set_mac(struct novena_eeprom *eeprom)
{
struct device_node *dnode;
dnode = of_find_node_by_alias(of_get_root_node(), "ethernet0");
if (dnode)
of_eth_register_ethaddr(dnode, eeprom->mac);
else
pr_err("Unable to find ethernet node\n");
}
static int novena_probe(struct device *dev)
{
struct novena_eeprom *eeprom = novena_read_eeprom();
if (eeprom && novena_check_eeprom(eeprom))
novena_set_mac(eeprom);
free(eeprom);
return 0;
}
static const struct of_device_id novena_of_match[] = {
{ .compatible = "kosagi,imx6q-novena", },
{ /* sentinel */ }
};
static struct driver novena_board_driver = {
.name = "board-novena",
.probe = novena_probe,
.of_compatible = novena_of_match,
};
coredevice_platform_driver(novena_board_driver);
BAREBOX_DEEP_PROBE_ENABLE(novena_of_match);
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