zephyr/drivers/flash/flash_stm32l4x.c

153 lines
3.2 KiB
C

/*
* Copyright (c) 2017 Linaro Limited
* Copyright (c) 2017 BayLibre, SAS
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <kernel.h>
#include <device.h>
#include <string.h>
#include <flash.h>
#include <init.h>
#include <soc.h>
#include <flash_stm32.h>
#define STM32L4X_BANK_SIZE_MAX 512
#define STM32L4X_PAGE_SHIFT 11
#define STM32L4X_FLASH_END \
((u32_t)(STM32L4X_BANK_SIZE_MAX << STM32L4X_PAGE_SHIFT) - 1)
/* offset and len must be aligned on 8, positive and not beyond end of flash */
bool flash_stm32_valid_range(off_t offset, u32_t len)
{
return offset % 8 == 0 &&
len % 8 == 0 &&
offset >= 0 &&
(offset + len - 1 <= STM32L4X_FLASH_END);
}
/* STM32L4xx devices can have up to 512 2K pages on two 256x2K pages banks */
static unsigned int get_page(off_t offset)
{
return offset >> STM32L4X_PAGE_SHIFT;
}
static int write_dword(off_t offset, u64_t val, struct flash_stm32_priv *p)
{
volatile u32_t *flash = (u32_t *)(offset + CONFIG_FLASH_BASE_ADDRESS);
struct stm32l4x_flash *regs = p->regs;
u32_t tmp;
int rc;
/* if the control register is locked, do not fail silently */
if (regs->cr & FLASH_CR_LOCK) {
return -EIO;
}
/* Check that no Flash main memory operation is ongoing */
rc = flash_stm32_wait_flash_idle(p);
if (rc < 0) {
return rc;
}
/* Check if this double word is erased */
if (flash[0] != 0xFFFFFFFFUL ||
flash[1] != 0xFFFFFFFFUL) {
return -EIO;
}
/* Set the PG bit */
regs->cr |= FLASH_CR_PG;
/* Flush the register write */
tmp = regs->cr;
/* Perform the data write operation at the desired memory address */
flash[0] = (uint32_t)val;
flash[1] = (uint32_t)(val >> 32);
/* Wait until the BSY bit is cleared */
rc = flash_stm32_wait_flash_idle(p);
/* Clear the PG bit */
regs->cr &= (~FLASH_CR_PG);
return rc;
}
static int erase_page(unsigned int page, struct flash_stm32_priv *p)
{
struct stm32l4x_flash *regs = p->regs;
u32_t tmp;
int rc;
/* if the control register is locked, do not fail silently */
if (regs->cr & FLASH_CR_LOCK) {
return -EIO;
}
/* Check that no Flash memory operation is ongoing */
rc = flash_stm32_wait_flash_idle(p);
if (rc < 0) {
return rc;
}
/* Set the PER bit and select the page you wish to erase */
regs->cr |= FLASH_CR_PER;
#ifdef FLASH_CR_BKER
regs->cr &= ~FLASH_CR_BKER_Msk;
/* Select bank, only for DUALBANK devices */
if (page >= 256)
regs->cr |= FLASH_CR_BKER;
#endif
regs->cr &= ~FLASH_CR_PNB_Msk;
regs->cr |= ((page % 256) << 3);
/* Set the STRT bit */
regs->cr |= FLASH_CR_STRT;
/* flush the register write */
tmp = regs->cr;
/* Wait for the BSY bit */
rc = flash_stm32_wait_flash_idle(p);
regs->cr &= ~FLASH_CR_PER;
return rc;
}
int flash_stm32_block_erase_loop(unsigned int offset, unsigned int len,
struct flash_stm32_priv *p)
{
int i, rc = 0;
i = get_page(offset);
for (; i <= get_page(offset + len - 1) ; ++i) {
rc = erase_page(i, p);
if (rc < 0) {
break;
}
}
return rc;
}
int flash_stm32_write_range(unsigned int offset, const void *data,
unsigned int len, struct flash_stm32_priv *p)
{
int i, rc = 0;
for (i = 0; i < len; i += 8, offset += 8) {
rc = write_dword(offset, ((const u64_t *) data)[i], p);
if (rc < 0) {
return rc;
}
}
return rc;
}