flashpage.c
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/*
* Copyright (C) 2016 Freie Universität Berlin
*
* This file is subject to the terms and conditions of the GNU Lesser
* General Public License v2.1. See the file LICENSE in the top level
* directory for more details.
*/
/**
* @ingroup cpu_sam0_common
* @ingroup drivers_periph_adc
* @{
*
* @file
* @brief Low-level flash page driver implementation
*
* The sam0 has its flash memory organized in pages and rows, where each row
* consists of 4 pages. While pages are writable one at a time, it is only
* possible to delete a complete row. This implementation abstracts this
* behavior by only writing complete rows at a time, so the FLASH_PAGE_SIZE we
* use in RIOT is actually the row size as specified in the datasheet.
*
* @author Hauke Petersen <hauke.petersen@fu-berlin.de>
*
* @}
*/
#include "cpu.h"
#include "assert.h"
#include "periph/flashpage.h"
#define NVMCTRL_PAC_BIT (0x00000002)
void flashpage_write(int page, void *data)
{
assert(page < FLASHPAGE_NUMOF);
uint32_t *page_addr = (uint32_t *)flashpage_addr(page);
/* remove peripheral access lock for the NVMCTRL peripheral */
#ifdef CPU_FAM_SAML21
PAC->WRCTRL.reg = (PAC_WRCTRL_KEY_CLR | ID_NVMCTRL);
#else
if (PAC1->WPSET.reg & NVMCTRL_PAC_BIT) {
PAC1->WPCLR.reg = NVMCTRL_PAC_BIT;
}
#endif
/* erase given page (the ADDR register uses 16-bit addresses) */
NVMCTRL->ADDR.reg = (((uint32_t)page_addr) >> 1);
NVMCTRL->CTRLA.reg = (NVMCTRL_CTRLA_CMDEX_KEY | NVMCTRL_CTRLA_CMD_ER);
while (!NVMCTRL->INTFLAG.bit.READY) {}
/* write data to page */
if (data != NULL) {
uint32_t *data_addr = (uint32_t *)data;
NVMCTRL->CTRLA.reg = (NVMCTRL_CTRLA_CMDEX_KEY | NVMCTRL_CTRLA_CMD_PBC);
for (unsigned i = 0; i < (FLASHPAGE_SIZE / 4); i++) {
*page_addr++ = data_addr[i];
}
NVMCTRL->CTRLA.reg = (NVMCTRL_CTRLA_CMDEX_KEY | NVMCTRL_CTRLA_CMD_WP);
}
}