flash: stm32: distinguish read/write for flash range valid

L4 write access requires 64 bits alignment
while L4 read access does not require any alignment.
To support specific check according to read/write,erase
a parameter is added to stm32_valid_range.

Signed-off-by: Michel Jaouen <[email protected]>

Author: jamike

drivers/flash/flash_stm32.c

@@ -95,7 +95,7 @@ void flash_stm32_flush_caches(struct flash_stm32_priv *p)
 static int flash_stm32_read(struct device *dev, off_t offset, void *data,
 			    size_t len)
 {
-	if (!flash_stm32_valid_range(offset, len)) {
+	if (!flash_stm32_valid_range(offset, len, false)) {
 		return -EINVAL;
 	}
 
@@ -113,7 +113,7 @@ int flash_stm32_erase(struct device *dev, off_t offset, size_t len)
 	struct flash_stm32_priv *p = dev->driver_data;
 	int rc;
 
-	if (!flash_stm32_valid_range(offset, len)) {
+	if (!flash_stm32_valid_range(offset, len, true)) {
 		return -EINVAL;
 	}
 
@@ -138,7 +138,7 @@ int flash_stm32_write(struct device *dev, off_t offset,
 	struct flash_stm32_priv *p = dev->driver_data;
 	int rc;
 
-	if (!flash_stm32_valid_range(offset, len)) {
+	if (!flash_stm32_valid_range(offset, len, true)) {
 		return -EINVAL;
 	}
 

drivers/flash/flash_stm32.h

@@ -30,7 +30,7 @@ struct flash_stm32_priv {
 	struct k_sem sem;
 };
 
-bool flash_stm32_valid_range(off_t offset, u32_t len);
+bool flash_stm32_valid_range(off_t offset, u32_t len, bool write);
 
 int flash_stm32_write_range(unsigned int offset, const void *data,
 			    unsigned int len, struct flash_stm32_priv *p);

drivers/flash/flash_stm32f4x.c

@@ -13,8 +13,9 @@
 
 #include <flash_stm32.h>
 
-bool flash_stm32_valid_range(off_t offset, u32_t len)
+bool flash_stm32_valid_range(off_t offset, u32_t len, bool write)
 {
+	ARG_UNUSED(write);
 	return offset >= 0 && (offset + len - 1 <= STM32F4X_FLASH_END);
 }
 

drivers/flash/flash_stm32l4x.c

@@ -20,13 +20,13 @@
 #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)
+/* offset and len must be aligned on 8 for write
+ * , positive and not beyond end of flash */
+bool flash_stm32_valid_range(off_t offset, u32_t len, bool write)
 {
-	return offset % 8 == 0 &&
-	       len % 8 == 0 &&
-	       offset >= 0 &&
-	       (offset + len - 1 <= STM32L4X_FLASH_END);
+	return (!write || (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 */