[nrf fromtree] drivers: flash_mspi_nor: Take into account MSPI controller packet limit

drivers/flash/flash_mspi_nor.c

@@ -336,6 +336,7 @@
 static int api_read(const struct device *dev, off_t addr, void *dest,
 		    size_t size)
 {
+	const struct flash_mspi_nor_config *dev_config = dev->config;
 	struct flash_mspi_nor_data *dev_data = dev->data;
 	const uint32_t flash_size = dev_flash_size(dev);
 	int rc;
@@ -353,11 +354,26 @@
 		return rc;
 	}
 
-	set_up_xfer_with_addr(dev, MSPI_RX, addr);
-	dev_data->xfer.rx_dummy = get_rx_dummy(dev);
-	dev_data->packet.data_buf  = dest;
-	dev_data->packet.num_bytes = size;
-	rc = perform_xfer(dev, dev_data->cmd_info.read_cmd, true);
+	while (size > 0) {
+		uint32_t to_read;
+
+		if (dev_config->packet_data_limit &&
+		    dev_config->packet_data_limit < size) {
+			to_read = dev_config->packet_data_limit;
+		} else {
+			to_read = size;
+		}
+
+		set_up_xfer_with_addr(dev, MSPI_RX, addr);
+		dev_data->xfer.rx_dummy = get_rx_dummy(dev);
+		dev_data->packet.data_buf  = dest;
+		dev_data->packet.num_bytes = to_read;
+		rc = perform_xfer(dev, dev_data->cmd_info.read_cmd, true);
+
+		addr += to_read;
+		dest  = (uint8_t *)dest + to_read;
+		size -= to_read;
+	}
 
 	release(dev);
 
@@ -1294,13 +1310,22 @@
 #define INIT_PRIORITY UTIL_INC(CONFIG_MSPI_INIT_PRIORITY)
 #endif
 
+#define PACKET_DATA_LIMIT(inst) \
+	DT_PROP_OR(DT_INST_BUS(inst), packet_data_limit, 0)
+
 #define FLASH_MSPI_NOR_INST(inst)						\
+	BUILD_ASSERT(!PACKET_DATA_LIMIT(inst) ||				\
+		     FLASH_PAGE_SIZE(inst) <= PACKET_DATA_LIMIT(inst),		\
+		"Page size for " DT_NODE_FULL_NAME(DT_DRV_INST(inst))		\
+		" exceeds controller packet data limit");			\
 	SFDP_BUILD_ASSERTS(inst);						\
 	PM_DEVICE_DT_INST_DEFINE(inst, dev_pm_action_cb);			\
 	DEFAULT_ERASE_TYPES_DEFINE(inst);					\
 	static struct flash_mspi_nor_data dev##inst##_data;			\
 	static const struct flash_mspi_nor_config dev##inst##_config = {	\
 		.bus = DEVICE_DT_GET(DT_INST_BUS(inst)),			\
+		.packet_data_limit = DT_PROP_OR(DT_INST_BUS(inst),		\
+						packet_data_limit, 0),		\
 		.flash_size = FLASH_SIZE(inst),					\
 		.page_size = FLASH_PAGE_SIZE(inst),				\
 		.mspi_id = MSPI_DEVICE_ID_DT_INST(inst),			\
@@ -1336,5 +1361,5 @@
 		&dev##inst##_data, &dev##inst##_config,				\
 		POST_KERNEL, INIT_PRIORITY,					\
 		&drv_api);
 
 DT_INST_FOREACH_STATUS_OKAY(FLASH_MSPI_NOR_INST)

drivers/flash/flash_mspi_nor.h

@@ -70,6 +70,7 @@ struct flash_mspi_nor_switch_info {
 
 struct flash_mspi_nor_config {
 	const struct device *bus;
+	uint32_t packet_data_limit;
 	uint32_t flash_size;
 	uint16_t page_size;
 	struct mspi_dev_id mspi_id;

dts/bindings/mspi/mspi-controller.yaml

@@ -92,3 +92,11 @@ properties:
       Regardless of whether the CE pin may need software control or MSPI
       controller has dedicated CE pin, this field should be defined to
       help manage multiple devices on the same MSPI controller.
+
+  packet-data-limit:
+    type: int
+    description: |
+      Specifies the maximum length of data that the controller can transfer
+      in a single packet. Transceive requests made to the controller must be
+      split into multiple packets if a single one would exceed this value.
+      If not specified, no limit is imposed.

dts/bindings/mspi/snps,designware-ssi.yaml

@@ -14,6 +14,10 @@ properties:
   interrupts:
     required: true
 
+  packet-data-limit:
+    required: true
+    const: 65536
+
   aux-reg-enable:
     type: boolean
     description: |

dts/vendor/nordic/nrf54h20.dtsi

@@ -649,6 +649,7 @@
 				interrupts = <149 NRF_DEFAULT_IRQ_PRIORITY>;
 				power-domains = <&gdpwr_fast_active_0>;
 				clock-frequency = <DT_FREQ_M(400)>;
+				packet-data-limit = <65536>;
 				fifo-depth = <32>;
 				status = "disabled";
 			};

dts/vendor/nordic/nrf9280.dtsi

@@ -384,6 +384,7 @@
 				reg-names = "wrapper", "core";
 				interrupts = <149 NRF_DEFAULT_IRQ_PRIORITY>;
 				clock-frequency = <DT_FREQ_M(400)>;
+				packet-data-limit = <65536>;
 				fifo-depth = <32>;
 				status = "disabled";
 			};