stm32g4: Implement FLASH

lib/stm32/g4/Makefile

@@ -35,6 +35,7 @@ TGT_CFLAGS      += $(DEBUG_FLAGS)
 TGT_CFLAGS	+= $(STANDARD_FLAGS)
 ARFLAGS		= rcs
 
+OBJS += flash.o flash_common_all.o flash_common_f.o flash_common_idcache.o
 OBJS += gpio_common_all.o gpio_common_f0234.o
 OBJS += pwr.o
 OBJS += rcc_common_all.o

lib/stm32/g4/flash.c

@@ -0,0 +1,209 @@
+/** @defgroup flash_file FLASH peripheral API
+ *
+ * @ingroup peripheral_apis
+ *
+ * @brief <b>libopencm3 STM32G4xx FLASH</b>
+ *
+ * @version 1.0.0
+ *
+ * Benjamin Levine <benjamin@jesco.karoo.co.uk>
+ * Ben Brewer <ben.brewer@codethink.co.uk>
+ *
+ * @date 30 July 2020
+ *
+ * This library supports the FLASH memory controller in the STM32G4
+ * series of ARM Cortex Microcontrollers by ST Microelectronics.
+ *
+ * For the STM32G4xx, accessing FLASH memory is described briefly in
+ * section 3 of the STM32G4 Reference Manual.
+ *
+ * LGPL License Terms @ref lgpl_license
+ */
+
+/*
+ * This file is part of the libopencm3 project.
+ *
+ * Copyright (C) 2016 Benjamin Levine <benjamin@jesco.karoo.co.uk>
+ * Copyright (C) 2020 Ben Brewer <ben.brewer@codethink.co.uk>
+ *
+ * This library is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This library 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 Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this library.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/**@{*/
+
+#include <libopencm3/stm32/flash.h>
+
+/** @brief Wait until Last Operation has Ended
+ * This loops indefinitely until an operation (write or erase) has completed
+ * by testing the busy flag.
+ */
+void flash_wait_for_last_operation(void)
+{
+	while ((FLASH_SR & FLASH_SR_BSY) == FLASH_SR_BSY);
+}
+
+/** @brief Clear the Programming Sequence Error Flag
+ * This flag is set when incorrect programming configuration has been made.
+ */
+void flash_clear_pgserr_flag(void)
+{
+	FLASH_SR |= FLASH_SR_PGSERR;
+}
+
+/** Clear programming size error flag */
+void flash_clear_size_flag(void)
+{
+	FLASH_SR |= FLASH_SR_SIZERR;
+}
+
+/** @brief Clear the Programming Alignment Error Flag
+ */
+void flash_clear_pgaerr_flag(void)
+{
+	FLASH_SR |= FLASH_SR_PGAERR;
+}
+
+/** @brief Clear the Write Protect Error Flag
+ */
+void flash_clear_wrperr_flag(void)
+{
+	FLASH_SR |= FLASH_SR_WRPERR;
+}
+
+/** @brief Clear the Programming Error Status Flag
+ */
+void flash_clear_progerr_flag(void)
+{
+	FLASH_SR |= FLASH_SR_PROGERR;
+}
+
+/** @brief Clear All Status Flags
+ * Program error, end of operation, write protect error, busy.
+ */
+void flash_clear_status_flags(void)
+{
+	flash_clear_pgserr_flag();
+	flash_clear_size_flag();
+	flash_clear_pgaerr_flag();
+	flash_clear_wrperr_flag();
+	flash_clear_progerr_flag();
+	flash_clear_eop_flag();
+}
+
+/** @brief Lock the Option Byte Access
+ * This disables write access to the option bytes. It is locked by default on
+ * reset.
+ */
+void flash_lock_option_bytes(void)
+{
+	FLASH_CR |= FLASH_CR_OPTLOCK;
+}
+
+/** @brief Program a 64 bit word to FLASH
+ *
+ * This performs all operations necessary to program a 64 bit word to FLASH memory.
+ * The program error flag should be checked separately for the event that memory
+ * was not properly erased.
+ *
+ * @param[in] address Starting address in Flash.
+ * @param[in] data Double word to write
+ */
+void flash_program_double_word(uint32_t address, uint64_t data)
+{
+	/* Ensure that all flash operations are complete. */
+	flash_wait_for_last_operation();
+
+	/* Enable writes to flash. */
+	FLASH_CR |= FLASH_CR_PG;
+
+	/* Program the each word separately. */
+	MMIO32(address) = (uint32_t)data;
+	MMIO32(address+4) = (uint32_t)(data >> 32);
+
+	/* Wait for the write to complete. */
+	flash_wait_for_last_operation();
+
+	/* Disable writes to flash. */
+	FLASH_CR &= ~FLASH_CR_PG;
+}
+
+/** @brief Program a Data Block to FLASH
+ * This programs an arbitrary length data block to FLASH memory.
+ * The program error flag should be checked separately for the event that
+ * memory was not properly erased.
+ * @param[in] address Starting address in Flash.
+ * @param[in] data Pointer to start of data block.
+ * @param[in] len Length of data block in bytes (multiple of 8).
+ */
+void flash_program(uint32_t address, uint8_t *data, uint32_t len)
+{
+	for (uint32_t i = 0; i < len; i += 8) {
+		flash_program_double_word(address+i, *(uint64_t*)(data + i));
+	}
+}
+
+/** @brief Erase a page of FLASH
+ * @param[in] page (0 - 255 for bank 1, 256-511 for bank 2)
+ */
+void flash_erase_page(uint32_t page)
+{
+	flash_wait_for_last_operation();
+
+	/* page and bank are contiguous bits */
+	FLASH_CR &= ~((FLASH_CR_PNB_MASK << FLASH_CR_PNB_SHIFT) | FLASH_CR_BKER);
+	if (page > 255)	{
+		FLASH_CR |= FLASH_CR_BKER;
+	}
+	FLASH_CR |= page << FLASH_CR_PNB_SHIFT;
+	FLASH_CR |= FLASH_CR_PER;
+	FLASH_CR |= FLASH_CR_START;
+
+	flash_wait_for_last_operation();
+	FLASH_CR &= ~FLASH_CR_PER;
+}
+
+/** @brief Erase All FLASH
+ * This performs all operations necessary to erase all sectors in the FLASH
+ * memory.
+ */
+void flash_erase_all_pages(void)
+{
+	flash_wait_for_last_operation();
+
+	FLASH_CR |= FLASH_CR_MER1 | FLASH_CR_MER2;
+	FLASH_CR |= FLASH_CR_START;
+
+	flash_wait_for_last_operation();
+	FLASH_CR &= ~FLASH_CR_MER1 & ~FLASH_CR_MER2;
+}
+
+/** @brief Program the Option Bytes
+ * This performs all operations necessary to program the option bytes.
+ * The option bytes do not need to be erased first.
+ * @param[in] data value to be programmed.
+ */
+void flash_program_option_bytes(uint32_t data)
+{
+	flash_wait_for_last_operation();
+
+	if (FLASH_CR & FLASH_CR_OPTLOCK) {
+		flash_unlock_option_bytes();
+	}
+
+	FLASH_OPTR = data;
+	FLASH_CR |= FLASH_CR_OPTSTRT;
+	flash_wait_for_last_operation();
+}
+/**@}*/
+