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

Use information provided in the dts node for the MSPI controller
regarding maximum amount of data that can be transferred in one
packet and split the requested transfers if necessary.

Signed-off-by: Andrzej Głąbek <[email protected]>
(cherry picked from commit c3469a6)

Author: anangl

drivers/flash/flash_mspi_nor.c

@@ -336,6 +336,7 @@ static uint8_t get_rx_dummy(const struct device *dev)
 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 @@ static int api_read(const struct device *dev, off_t addr, void *dest,
 		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 @@ BUILD_ASSERT((FLASH_SIZE(inst) % CONFIG_FLASH_MSPI_NOR_LAYOUT_PAGE_SIZE) == 0, \
 #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),			\

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;