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Diffstat (limited to 'drivers/eeprom/eeprom_stm32_L0_L1.c')
-rw-r--r--drivers/eeprom/eeprom_stm32_L0_L1.c96
1 files changed, 96 insertions, 0 deletions
diff --git a/drivers/eeprom/eeprom_stm32_L0_L1.c b/drivers/eeprom/eeprom_stm32_L0_L1.c
new file mode 100644
index 000000000..b62e6ffd7
--- /dev/null
+++ b/drivers/eeprom/eeprom_stm32_L0_L1.c
@@ -0,0 +1,96 @@
+/* Copyright 2020 Nick Brassel (tzarc)
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdint.h>
+#include <string.h>
+
+#include "hal.h"
+#include "eeprom_driver.h"
+#include "eeprom_stm32_L0_L1.h"
+
+#define EEPROM_BASE_ADDR 0x08080000
+#define EEPROM_ADDR(offset) (EEPROM_BASE_ADDR + (offset))
+#define EEPROM_PTR(offset) ((__IO uint8_t *)EEPROM_ADDR(offset))
+#define EEPROM_BYTE(location, offset) (*(EEPROM_PTR(((uint32_t)location) + ((uint32_t)offset))))
+
+#define BUFFER_BYTE(buffer, offset) (*(((uint8_t *)buffer) + offset))
+
+#define FLASH_PEKEY1 0x89ABCDEF
+#define FLASH_PEKEY2 0x02030405
+
+static inline void STM32_L0_L1_EEPROM_WaitNotBusy(void) {
+ while (FLASH->SR & FLASH_SR_BSY) {
+ __WFI();
+ }
+}
+
+static inline void STM32_L0_L1_EEPROM_Unlock(void) {
+ STM32_L0_L1_EEPROM_WaitNotBusy();
+ if (FLASH->PECR & FLASH_PECR_PELOCK) {
+ FLASH->PEKEYR = FLASH_PEKEY1;
+ FLASH->PEKEYR = FLASH_PEKEY2;
+ }
+}
+
+static inline void STM32_L0_L1_EEPROM_Lock(void) {
+ STM32_L0_L1_EEPROM_WaitNotBusy();
+ FLASH->PECR |= FLASH_PECR_PELOCK;
+}
+
+void eeprom_driver_init(void) {}
+
+void eeprom_driver_erase(void) {
+ STM32_L0_L1_EEPROM_Unlock();
+
+ for (size_t offset = 0; offset < STM32_ONBOARD_EEPROM_SIZE; offset += sizeof(uint32_t)) {
+ FLASH->PECR |= FLASH_PECR_ERASE | FLASH_PECR_DATA;
+
+ *(__IO uint32_t *)EEPROM_ADDR(offset) = (uint32_t)0;
+
+ STM32_L0_L1_EEPROM_WaitNotBusy();
+ FLASH->PECR &= ~(FLASH_PECR_ERASE | FLASH_PECR_DATA);
+ }
+
+ STM32_L0_L1_EEPROM_Lock();
+}
+
+void eeprom_read_block(void *buf, const void *addr, size_t len) {
+ for (size_t offset = 0; offset < len; ++offset) {
+ // Drop out if we've hit the limit of the EEPROM
+ if ((((uint32_t)addr) + offset) >= STM32_ONBOARD_EEPROM_SIZE) {
+ break;
+ }
+
+ STM32_L0_L1_EEPROM_WaitNotBusy();
+ BUFFER_BYTE(buf, offset) = EEPROM_BYTE(addr, offset);
+ }
+}
+
+void eeprom_write_block(const void *buf, void *addr, size_t len) {
+ STM32_L0_L1_EEPROM_Unlock();
+
+ for (size_t offset = 0; offset < len; ++offset) {
+ // Drop out if we've hit the limit of the EEPROM
+ if ((((uint32_t)addr) + offset) >= STM32_ONBOARD_EEPROM_SIZE) {
+ break;
+ }
+
+ STM32_L0_L1_EEPROM_WaitNotBusy();
+ EEPROM_BYTE(addr, offset) = BUFFER_BYTE(buf, offset);
+ }
+
+ STM32_L0_L1_EEPROM_Lock();
+}