flash: implement functions to check if pages are all zero or one

include/flash.h

@@ -24,7 +24,8 @@ struct flash_dev {
 	uint8_t log2_block_size;
 };
 
-int default_flash_is_erased(struct flash_dev *dev, uint32_t addr);
+int default_flash_is_zero(struct flash_dev *dev, uint32_t addr);
+int default_flash_is_one(struct flash_dev *dev, uint32_t addr);
 size_t default_flash_copy(struct flash_dev *dev, uint32_t dst, uint32_t src,
 	size_t len);
 

source/core/flash.c

@@ -5,9 +5,9 @@
 #include <flash.h>
 #include <macros.h>
 
-int default_flash_is_erased(struct flash_dev *dev, uint32_t addr)
+static int default_flash_is_val(struct flash_dev *dev, uint32_t addr, char val)
 {
-	uint8_t data[32];
+	char data[32];
 	size_t i, nbytes, len = 1 << dev->log2_block_size;
 
 	addr <<= dev->log2_block_size;
@@ -19,7 +19,7 @@ int default_flash_is_erased(struct flash_dev *dev, uint32_t addr)
 			return 0;
 
 		for (i = 0; i < sizeof(data); ++i) {
-			if (data[i] != 0xff)
+			if (data[i] != val)
 				return 0;
 		}
 
@@ -30,6 +30,16 @@ int default_flash_is_erased(struct flash_dev *dev, uint32_t addr)
 	return 1;
 }
 
+int default_flash_is_zero(struct flash_dev *dev, uint32_t addr)
+{
+	return default_flash_is_val(dev, addr, 0);
+}
+
+int default_flash_is_one(struct flash_dev *dev, uint32_t addr)
+{
+	return default_flash_is_val(dev, addr, 0xff);
+}
+
 size_t default_flash_copy(struct flash_dev *dev, uint32_t dst, uint32_t src,
 	size_t len)
 {

source/drivers/spi_flash.c

@@ -24,7 +24,7 @@ static struct flash_ops spi_flash_ops = {
 	.read = spi_flash_read,
 	.write = spi_flash_write,
 	.copy = default_flash_copy,
-	.is_erased = default_flash_is_erased,
+	.is_erased = default_flash_is_one,
 	.erase = spi_flash_erase,
 };