drivers/flash: deprecation of flash_write_protection_set() API

doc/releases/release-notes-2.6.rst

@@ -80,6 +80,8 @@ Deprecated in this release
   Disk API header ``<include/disk/disk_access.h>`` is deprecated in favor of
   ``<include/storage/disk_access.h>``.
 
+* :c:func:`flash_write_protection_set()`.
+
 ==========================
 
 Removed APIs in this release
@@ -184,6 +186,18 @@ Drivers and Sensors
 
 * Flash
 
+  * flash_write_protection_set() has been deprecated and will be removed in
+    Zephyr 2.8. Responsibility for write/erase protection management has been
+    moved to the driver-specific implementation of the flash_write() and
+    flash_erase() API calls. All in-tree flash drivers have been updated,
+    and the protect implementation removed from their API tables.
+    During the deprecation period user code invoking
+    flash_write_protection_set() will have no effect, but the flash_write() and
+    flash_erase() driver shims will wrap their calls with calls to the protect
+    implementation if it is present in the API table.
+    Out-of-tree drivers must be updated before the wrapping in the shims is
+    removed when the deprecation period ends.
+
 * GPIO
 
 * Hardware Info

drivers/disk/flashdisk.c

@@ -159,8 +159,6 @@ static int update_flash_block(off_t start_addr, uint32_t size, const void *buff)
 	/* always align starting address for flash write operation */
 	fl_addr = ROUND_DOWN(start_addr, CONFIG_DISK_FLASH_ERASE_ALIGNMENT);
 
-	/* disable write-protection first before erase */
-	flash_write_protection_set(flash_dev, false);
 	if (flash_erase(flash_dev, fl_addr, CONFIG_DISK_ERASE_BLOCK_SIZE)
 			!= 0) {
 		return -EIO;
@@ -171,9 +169,6 @@ static int update_flash_block(off_t start_addr, uint32_t size, const void *buff)
 				  CONFIG_DISK_FLASH_MAX_RW_SIZE);
 
 	for (uint32_t i = 0; i < num_write; i++) {
-		/* flash_write reenabled write-protection so disable it again */
-		flash_write_protection_set(flash_dev, false);
-
 		if (flash_write(flash_dev, fl_addr, src,
 				CONFIG_DISK_FLASH_MAX_RW_SIZE) != 0) {
 			return -EIO;

drivers/eeprom/eeprom_emulator.c

@@ -127,13 +127,8 @@ static inline int eeprom_emu_flash_write(const struct device *dev, off_t offset,
 	const struct eeprom_emu_config *dev_config = DEV_CONFIG(dev);
 	int rc;
 
-	if (flash_write_protection_set(dev_config->flash_dev, false)) {
-		return -EIO;
-	}
-
 	rc = flash_write(dev_config->flash_dev, dev_config->flash_offset +
 			 offset, blk, len);
-	(void)flash_write_protection_set(dev_config->flash_dev, true);
 	return rc;
 }
 
@@ -147,13 +142,8 @@ static inline int eeprom_emu_flash_erase(const struct device *dev, off_t offset,
 	const struct eeprom_emu_config *dev_config = DEV_CONFIG(dev);
 	int rc;
 
-	if (flash_write_protection_set(dev_config->flash_dev, false)) {
-		return -EIO;
-	}
-
 	rc = flash_erase(dev_config->flash_dev, dev_config->flash_offset +
 			 offset, len);
-	(void)flash_write_protection_set(dev_config->flash_dev, true);
 	return rc;
 }
 

drivers/flash/Kconfig.simulator

@@ -28,12 +28,6 @@ config FLASH_SIMULATOR_DOUBLE_WRITES
 	 If selected, writing to a non-erased program unit will succeed, otherwise, it will return an error.
 	 Keep in mind that write operations can only pull bits to zero, regardless.
 
-config FLASH_SIMULATOR_ERASE_PROTECT
-	bool "Enable erase protection on write protection"
-	default y
-	help
-	 If selected, turning on write protection will also prevent erasing.
-
 config FLASH_SIMULATOR_SIMULATE_TIMING
 	bool "Enable hardware timing simulation"
 

drivers/flash/flash_esp32.c

@@ -560,11 +560,6 @@ static int flash_esp32_erase(const struct device *dev, off_t start, size_t len)
 	return rc;
 }
 
-static int flash_esp32_write_protection(const struct device *dev, bool enable)
-{
-	return 0;
-}
-
 #if CONFIG_FLASH_PAGE_LAYOUT
 static const struct flash_pages_layout flash_esp32_pages_layout = {
 	.pages_count = DT_REG_SIZE(SOC_NV_FLASH_NODE) / FLASH_ERASE_BLK_SZ,
@@ -601,7 +596,6 @@ static const struct flash_driver_api flash_esp32_driver_api = {
 	.read = flash_esp32_read,
 	.write = flash_esp32_write,
 	.erase = flash_esp32_erase,
-	.write_protection = flash_esp32_write_protection,
 	.get_parameters = flash_esp32_get_parameters,
 #ifdef CONFIG_FLASH_PAGE_LAYOUT
 	.page_layout = flash_esp32_page_layout,

drivers/flash/flash_gecko.c

@@ -37,6 +37,7 @@ static const struct flash_parameters flash_gecko_parameters = {
 static bool write_range_is_valid(off_t offset, uint32_t size);
 static bool read_range_is_valid(off_t offset, uint32_t size);
 static int erase_flash_block(off_t offset, size_t size);
+static void flash_gecko_write_protection(bool enable);
 
 static int flash_gecko_read(const struct device *dev, off_t offset,
 			    void *data,
@@ -72,13 +73,15 @@ static int flash_gecko_write(const struct device *dev, off_t offset,
 	}
 
 	k_sem_take(&dev_data->mutex, K_FOREVER);
+	flash_gecko_write_protection(false);
 
 	address = (uint8_t *)CONFIG_FLASH_BASE_ADDRESS + offset;
 	msc_ret = MSC_WriteWord(address, data, size);
 	if (msc_ret < 0) {
 		ret = -EIO;
 	}
 
+	flash_gecko_write_protection(true);
 	k_sem_give(&dev_data->mutex);
 
 	return ret;
@@ -109,20 +112,18 @@ static int flash_gecko_erase(const struct device *dev, off_t offset,
 	}
 
 	k_sem_take(&dev_data->mutex, K_FOREVER);
+	flash_gecko_write_protection(false);
 
 	ret = erase_flash_block(offset, size);
 
+	flash_gecko_write_protection(true);
 	k_sem_give(&dev_data->mutex);
 
 	return ret;
 }
 
-static int flash_gecko_write_protection(const struct device *dev, bool enable)
+static void flash_gecko_write_protection(bool enable)
 {
-	struct flash_gecko_data *const dev_data = DEV_DATA(dev);
-
-	k_sem_take(&dev_data->mutex, K_FOREVER);
-
 	if (enable) {
 		/* Lock the MSC module. */
 		MSC->LOCK = 0;
@@ -134,10 +135,6 @@ static int flash_gecko_write_protection(const struct device *dev, bool enable)
 		MSC->LOCK = MSC_UNLOCK_CODE;
 	#endif
 	}
-
-	k_sem_give(&dev_data->mutex);
-
-	return 0;
 }
 
 /* Note:
@@ -218,7 +215,6 @@ static const struct flash_driver_api flash_gecko_driver_api = {
 	.read = flash_gecko_read,
 	.write = flash_gecko_write,
 	.erase = flash_gecko_erase,
-	.write_protection = flash_gecko_write_protection,
 	.get_parameters = flash_gecko_get_parameters,
 #ifdef CONFIG_FLASH_PAGE_LAYOUT
 	.page_layout = flash_gecko_page_layout,

drivers/flash/flash_mcux_flexspi_nor.c

@@ -366,12 +366,6 @@ static int flash_flexspi_nor_erase(const struct device *dev, off_t offset,
 	return 0;
 }
 
-static int flash_flexspi_nor_write_protection(const struct device *dev,
-		bool enable)
-{
-	return 0;
-}
-
 static const struct flash_parameters *flash_flexspi_nor_get_parameters(
 		const struct device *dev)
 {
@@ -433,7 +427,6 @@ static int flash_flexspi_nor_init(const struct device *dev)
 }
 
 static const struct flash_driver_api flash_flexspi_nor_api = {
-	.write_protection = flash_flexspi_nor_write_protection,
 	.erase = flash_flexspi_nor_erase,
 	.write = flash_flexspi_nor_write,
 	.read = flash_flexspi_nor_read,

drivers/flash/flash_sam.c

@@ -57,6 +57,7 @@ static const struct flash_parameters flash_sam_parameters = {
 #define DEV_DATA(dev) \
 	((struct flash_sam_dev_data *const)(dev)->data)
 
+static int flash_sam_write_protection(const struct device *dev, bool enable);
 
 static inline void flash_sam_sem_take(const struct device *dev)
 {
@@ -187,29 +188,36 @@ static int flash_sam_write(const struct device *dev, off_t offset,
 
 	flash_sam_sem_take(dev);
 
-	rc = flash_sam_wait_ready(dev);
-	if (rc < 0) {
-		return rc;
+	rc = flash_sam_write_protection(dev, false);
+	if (rc >= 0) {
+		rc = flash_sam_wait_ready(dev);
 	}
 
-	while (len > 0) {
-		size_t eop_len, write_len;
+	if (rc >= 0) {
+		while (len > 0) {
+			size_t eop_len, write_len;
 
-		/* Maximum size without crossing a page */
-		eop_len = -(offset | ~(IFLASH_PAGE_SIZE - 1));
-		write_len = MIN(len, eop_len);
+			/* Maximum size without crossing a page */
+			eop_len = -(offset | ~(IFLASH_PAGE_SIZE - 1));
+			write_len = MIN(len, eop_len);
 
-		rc = flash_sam_write_page(dev, offset, data8, write_len);
-		if (rc < 0) {
-			goto done;
+			rc = flash_sam_write_page(dev, offset, data8, write_len);
+			if (rc < 0) {
+				break;
+			}
+
+			offset += write_len;
+			data8 += write_len;
+			len -= write_len;
 		}
+	}
+
+	int rc2 = flash_sam_write_protection(dev, true);
 
-		offset += write_len;
-		data8 += write_len;
-		len -= write_len;
+	if (!rc) {
+		rc = rc2;
 	}
 
-done:
 	flash_sam_sem_give(dev);
 
 	return rc;
@@ -274,15 +282,23 @@ static int flash_sam_erase(const struct device *dev, off_t offset, size_t len)
 
 	flash_sam_sem_take(dev);
 
-	/* Loop through the pages to erase */
-	for (i = offset; i < offset + len; i += FLASH_ERASE_BLK_SZ) {
-		rc = flash_sam_erase_block(dev, i);
-		if (rc < 0) {
-			goto done;
+	rc = flash_sam_write_protection(dev, false);
+	if (rc >= 0) {
+		/* Loop through the pages to erase */
+		for (i = offset; i < offset + len; i += FLASH_ERASE_BLK_SZ) {
+			rc = flash_sam_erase_block(dev, i);
+			if (rc < 0) {
+				break;
+			}
 		}
 	}
 
-done:
+	int rc2 = flash_sam_write_protection(dev, true);
+
+	if (!rc) {
+		rc = rc2;
+	}
+
 	flash_sam_sem_give(dev);
 
 	/*
@@ -300,8 +316,6 @@ static int flash_sam_write_protection(const struct device *dev, bool enable)
 	Efc *const efc = DEV_CFG(dev)->regs;
 	int rc = 0;
 
-	flash_sam_sem_take(dev);
-
 	if (enable) {
 		rc = flash_sam_wait_ready(dev);
 		if (rc < 0) {
@@ -313,7 +327,6 @@ static int flash_sam_write_protection(const struct device *dev, bool enable)
 	}
 
 done:
-	flash_sam_sem_give(dev);
 	return rc;
 }
 
@@ -354,7 +367,6 @@ static int flash_sam_init(const struct device *dev)
 }
 
 static const struct flash_driver_api flash_sam_api = {
-	.write_protection = flash_sam_write_protection,
 	.erase = flash_sam_erase,
 	.write = flash_sam_write,
 	.read = flash_sam_read,