blob: fc46c5d2b093c7fdd17df9972152b2b0d289c9af [file] [log] [blame]
/*
* Copyright (c) 2019 Aurelien Jarno
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <device.h>
#include <drivers/hwinfo.h>
#include <init.h>
#include <soc.h>
#include <string.h>
static uint8_t sam_uid[16];
ssize_t z_impl_hwinfo_get_device_id(uint8_t *buffer, size_t length)
{
if (length > sizeof(sam_uid)) {
length = sizeof(sam_uid);
}
memcpy(buffer, sam_uid, length);
return length;
}
/* On the Atmel SAM SoC series, the device id is located in the flash
* controller. The controller can either present the flash area containing
* the code, the unique identifier or the user signature area at the flash
* location. Therefore the function reading the device id must be executed
* from RAM with the interrupts disabled. To avoid executing this complex
* code each time the device id is requested, we do this at boot time at save
* the 128-bit value into RAM.
*/
__ramfunc static void hwinfo_sam_read_device_id(void)
{
Efc *efc = (Efc *)DT_REG_ADDR(DT_INST(0, atmel_sam_flash_controller));
uint8_t *flash = (uint8_t *)CONFIG_FLASH_BASE_ADDRESS;
int i;
/* Switch the flash controller to the unique identifier area. The flash
* is not available anymore, hence we have to wait for it to be *NOT*
* ready.
*/
efc->EEFC_FCR = EEFC_FCR_FKEY_PASSWD | EEFC_FCR_FCMD_STUI;
while ((efc->EEFC_FSR & EEFC_FSR_FRDY) == EEFC_FSR_FRDY) {
/* Wait */
}
/* Copy the 128-bit unique ID. We cannot use memcpy as it would
* execute code from flash.
*/
for (i = 0; i < sizeof(sam_uid); i++) {
sam_uid[i] = flash[i];
}
/* Switch back the controller to the flash area and wait for it to
* be ready.
*/
efc->EEFC_FCR = EEFC_FCR_FKEY_PASSWD | EEFC_FCR_FCMD_SPUI;
while ((efc->EEFC_FSR & EEFC_FSR_FRDY) != EEFC_FSR_FRDY) {
/* Wait */
}
}
static int hwinfo_sam_init(const struct device *arg)
{
Efc *efc = (Efc *)DT_REG_ADDR(DT_INST(0, atmel_sam_flash_controller));
uint32_t fmr;
int key;
/* Disable interrupts. */
key = irq_lock();
/* Disable code loop optimization and sequential code optimization. */
fmr = efc->EEFC_FMR;
#ifndef CONFIG_SOC_SERIES_SAM3X
efc->EEFC_FMR = (fmr & (~EEFC_FMR_CLOE)) | EEFC_FMR_SCOD;
#else
/* SAM3x does not have loop optimization (EEFC_FMR_CLOE) */
efc->EEFC_FMR |= EEFC_FMR_SCOD;
#endif
/* Read the device ID using code in RAM */
hwinfo_sam_read_device_id();
/* Restore code optimization settings. */
efc->EEFC_FMR = fmr;
/* Re-enable interrupts */
irq_unlock(key);
return 0;
}
SYS_INIT(hwinfo_sam_init, POST_KERNEL, CONFIG_KERNEL_INIT_PRIORITY_DEVICE);