drivers: flash_mspi_nor: Omit quad_enable_set() when QER is set to NONE

When the quad-enable-requirements property is set to "NONE" or is not
present, no Quad Enable operation should be performed.
This fixes an issue with the mx25uw6345g flash chip that is present
on the nRF54h20 DK and supports the Single I/O mode, but cannot be
used in that mode.

Signed-off-by: Andrzej Głąbek <[email protected]>

Author: anangl

drivers/flash/flash_mspi_nor.c

@@ -567,15 +567,20 @@ static int default_io_mode(const struct device *dev)
 	enum mspi_io_mode io_mode = dev_config->mspi_nor_cfg.io_mode;
 	int rc = 0;
 
-	/* For Quad 1-1-4 and 1-4-4, entering or leaving mode is defined in JEDEC216 BFP DW15 QER */
-	if (io_mode == MSPI_IO_MODE_SINGLE) {
-		rc = quad_enable_set(dev, false);
-	} else if ((io_mode == MSPI_IO_MODE_QUAD_1_1_4) || (io_mode == MSPI_IO_MODE_QUAD_1_4_4)) {
-		rc = quad_enable_set(dev, true);
-	}
+	if (dev_config->dw15_qer != JESD216_DW15_QER_VAL_NONE) {
+		/* For Quad 1-1-4 and 1-4-4, entering or leaving mode is defined
+		 * in JEDEC216 BFP DW15 QER
+		 */
+		if (io_mode == MSPI_IO_MODE_SINGLE) {
+			rc = quad_enable_set(dev, false);
+		} else if (io_mode == MSPI_IO_MODE_QUAD_1_1_4 ||
+			   io_mode == MSPI_IO_MODE_QUAD_1_4_4) {
+			rc = quad_enable_set(dev, true);
+		}
 
-	if (rc < 0) {
-		LOG_ERR("Failed to modify Quad Enable bit: %d", rc);
+		if (rc < 0) {
+			LOG_ERR("Failed to modify Quad Enable bit: %d", rc);
+		}
 	}
 
 	if ((dev_config->quirks != NULL) && (dev_config->quirks->post_switch_mode != NULL)) {
@@ -646,8 +651,10 @@ static int flash_chip_init(const struct device *dev)
 	/* Some chips reuse RESET pin for data in Quad modes:
 	 * force single line mode before resetting.
 	 */
-	if ((io_mode == MSPI_IO_MODE_SINGLE) || (io_mode == MSPI_IO_MODE_QUAD_1_1_4) ||
-	    (io_mode == MSPI_IO_MODE_QUAD_1_4_4)) {
+	if (dev_config->dw15_qer != JESD216_DW15_QER_VAL_NONE &&
+	    (io_mode == MSPI_IO_MODE_SINGLE ||
+	     io_mode == MSPI_IO_MODE_QUAD_1_1_4 ||
+	     io_mode == MSPI_IO_MODE_QUAD_1_4_4)) {
 		rc = quad_enable_set(dev, false);
 
 		if (rc < 0) {