tests: drivers: flash: Add test with buffer size over the bus packet limit

Applicable to flash devices with MSPI controller

Signed-off-by: Bartosz Miller <[email protected]>

Author: nordic-bami

tests/drivers/flash/common/src/main.c

@@ -77,6 +77,13 @@ static uint8_t __aligned(4) expected[EXPECTED_SIZE];
 static uint8_t erase_value;
 static bool ebw_required;
 
+#if DT_NODE_HAS_PROP(DT_BUS(TEST_AREA_DEV_NODE), packet_data_limit)
+#define BUFFER_SIZE_OVER_PACKET_LIMIT DT_PROP(DT_BUS(TEST_AREA_DEV_NODE), packet_data_limit) + 1
+static uint8_t large_data_buf[BUFFER_SIZE_OVER_PACKET_LIMIT];
+#else
+#define BUFFER_SIZE_OVER_PACKET_LIMIT 0
+#endif
+
 static void flash_driver_before(void *arg)
 {
 	int rc;
@@ -334,6 +341,41 @@ ZTEST(flash_driver, test_flash_erase)
 	zassert_not_equal(expected[0], erase_value, "These values shall be different");
 }
 
+ZTEST(flash_driver, test_flash_write_read_over_the_packet_limit)
+{
+	if (BUFFER_SIZE_OVER_PACKET_LIMIT == 0) {
+		ztest_test_skip();
+	}
+
+	TC_PRINT("SIZE: %u\n", BUFFER_SIZE_OVER_PACKET_LIMIT);
+
+	int rc;
+	const uint8_t pattern = 0xA1;
+
+	/* Set every byte in the buffer to the predefined pattern */
+	memset(large_data_buf, pattern, BUFFER_SIZE_OVER_PACKET_LIMIT);
+
+	/* Write flash area with buffer size over the configured packet limit */
+	rc = flash_write(flash_dev, page_info.start_offset, large_data_buf,
+			 BUFFER_SIZE_OVER_PACKET_LIMIT);
+	zassert_equal(rc, 0, "Cannot write flash");
+
+	/* Flush buffer */
+	memset(large_data_buf, 0xFF, BUFFER_SIZE_OVER_PACKET_LIMIT);
+
+	/* Read flash area with buffer size over the MSPI packet limit */
+	rc = flash_read(flash_dev, page_info.start_offset, large_data_buf,
+			BUFFER_SIZE_OVER_PACKET_LIMIT);
+	zassert_equal(rc, 0, "Cannot read flash");
+
+	/* Compare read data to the pre-defined pattern */
+	for (int i = 0; i < BUFFER_SIZE_OVER_PACKET_LIMIT; i++) {
+		zassert_equal(large_data_buf[i], pattern,
+			      "large_data_buf[%u]=%x read, does not match written pattern %x", i,
+			      large_data_buf[i], pattern);
+	}
+}
+
 ZTEST(flash_driver, test_supply_gpios_control)
 {
 	if (!DT_NODE_HAS_PROP(TEST_AREA_DEV_NODE, supply_gpios)) {