Add more support functions for flash handling.

Thanks to Mark Butler <mbutler@physics.otago.ac.nz>.

include/libopenstm32/flash.h

@@ -2,6 +2,7 @@
  * This file is part of the libopenstm32 project.
  *
  * Copyright (C) 2010 Thomas Otto <tommi@viadmin.org>
+ * Copyright (C) 2010 Mark Butler <mbutler@physics.otago.ac.nz>
  *
  * 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
@@ -80,6 +81,12 @@
 #define FLASH_RDPRT				(1 << 1)
 #define FLASH_OPTERR				(1 << 0)
 
+/* --- FLASH Keys -----------------------------------------------------------*/
+
+#define RDP_KEY					((u16)0x00a5)
+#define FLASH_KEY1				((u32)0x45670123)
+#define FLASH_KEY2				((u32)0xcdef89ab)
+
 /* --- Function prototypes ------------------------------------------------- */
 
 void flash_prefetch_buffer_enable(void);
@@ -87,5 +94,20 @@ void flash_prefetch_buffer_disable(void);
 void flash_halfcycle_enable(void);
 void flash_halfcycle_disable(void);
 void flash_set_ws(u32 ws);
+void flash_unlock(void);
+void flash_lock(void);
+void flash_clear_pgerr_flag(void);
+void flash_clear_eop_flag(void);
+void flash_clear_wrprterr_flag(void);
+void flash_clear_bsy_flag(void);
+void flash_clear_status_flags(void);
+void flash_unlock_option_bytes(void);
+void flash_erase_all_pages(void);
+void flash_erase_page(u32 page_address);
+void flash_program_word(u32 address, u32 data);
+void flash_program_half_word(u32 address, u16 data);
+void flash_wait_for_last_operation(void);
+void flash_erase_option_bytes(void);
+void flash_program_option_bytes(u32 address, u16 data);
 
 #endif

lib/flash.c

@@ -2,6 +2,7 @@
  * This file is part of the libopenstm32 project.
  *
  * Copyright (C) 2010 Thomas Otto <tommi@viadmin.org>
+ * Copyright (C) 2010 Mark Butler <mbutler@physics.otago.ac.nz>
  *
  * 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
@@ -48,3 +49,141 @@ void flash_set_ws(u32 ws)
 	reg32 |= ws;
 	FLASH_ACR = reg32;
 }
+
+void flash_unlock(void)
+{
+	/* Authorize the FPEC access. */
+	FLASH_KEYR = FLASH_KEY1;
+	FLASH_KEYR = FLASH_KEY2;
+}
+
+void flash_lock(void)
+{
+	FLASH_CR |= FLASH_LOCK;
+}
+
+void flash_clear_pgerr_flag(void)
+{
+	FLASH_SR |= FLASH_PGERR;
+}
+
+void flash_clear_eop_flag(void)
+{
+	FLASH_SR |= FLASH_EOP;
+}
+
+void flash_clear_wrprterr_flag(void)
+{
+	FLASH_SR |= FLASH_WRPRTERR;
+}
+
+void flash_clear_bsy_flag(void)
+{
+	FLASH_SR &= ~FLASH_BSY;
+}
+
+void flash_clear_status_flags(void)
+{
+	flash_clear_pgerr_flag();
+	flash_clear_eop_flag();
+	flash_clear_wrprterr_flag();
+	flash_clear_bsy_flag();
+}
+
+void flash_unlock_option_bytes(void)
+{
+	FLASH_OPTKEYR = FLASH_KEY1;
+	FLASH_OPTKEYR = FLASH_KEY2;
+}
+
+void flash_wait_for_last_operation(void)
+{
+	while ((FLASH_SR & FLASH_BSY) == FLASH_BSY)
+		;
+}
+
+void flash_program_word(u32 address, u32 data)
+{
+	/* Ensure that all flash operations are complete. */
+	flash_wait_for_last_operation();
+
+	/* Enable writes to flash. */
+	FLASH_CR |= FLASH_PG;
+
+	/* Program the first half of the word. */
+	(*(volatile u16 *)address) = (u16)data;
+
+	/* Wait for the write to complete. */
+	flash_wait_for_last_operation();
+
+	/* Program the second half of the word. */
+	(*(volatile u16 *)(address + 2)) = data >> 16;
+
+	/* Wait for the write to complete. */
+	flash_wait_for_last_operation();
+
+	/* Disable writes to flash. */
+	FLASH_CR &= ~FLASH_PG;
+}
+
+void flash_program_half_word(u32 address, u16 data)
+{
+	flash_wait_for_last_operation();
+
+	FLASH_CR |= FLASH_PG;
+
+	(*(volatile u16 *)address) = data;
+
+	flash_wait_for_last_operation();
+
+	FLASH_CR &= ~FLASH_PG;		/* Disable the PG bit. */
+}
+
+void flash_erase_page(u32 page_address)
+{
+	flash_wait_for_last_operation();
+
+	FLASH_CR |= FLASH_PER;
+	FLASH_AR = page_address;
+	FLASH_CR |= FLASH_STRT;
+
+	flash_wait_for_last_operation();
+	FLASH_CR &= ~FLASH_PER;
+}
+
+void flash_erase_all_pages(void)
+{
+	flash_wait_for_last_operation();
+
+	FLASH_CR |= FLASH_MER;		/* Enable mass erase. */
+	FLASH_CR |= FLASH_STRT;		/* Trigger the erase. */
+
+	flash_wait_for_last_operation();
+	FLASH_CR &= ~FLASH_MER;		/* Disable mass erase. */
+}
+
+void flash_erase_option_bytes(void)
+{
+	flash_wait_for_last_operation();
+
+	if ((FLASH_CR & FLASH_OPTWRE) == 0)
+		flash_unlock_option_bytes();
+
+	FLASH_CR |= FLASH_OPTER;	/* Enable option byte erase. */
+	FLASH_CR |= FLASH_STRT;
+	flash_wait_for_last_operation();
+	FLASH_CR &= ~FLASH_OPTER;	/* Disable option byte erase. */
+}
+
+void flash_program_option_bytes(u32 address, u16 data)
+{
+	flash_wait_for_last_operation();
+
+	if ((FLASH_CR & FLASH_OPTWRE) == 0)
+		flash_unlock_option_bytes();
+
+	FLASH_CR |= FLASH_OPTPG;	/* Enable option byte programming. */
+	(*(volatile u16 *)address) = data;
+	flash_wait_for_last_operation();
+	FLASH_CR &= ~FLASH_OPTPG;	/* Disable option byte programming. */
+}