drivers/flash: flash_stm32_qspi: Set DMA as optional

In order to ease reuse on other series, set DMA as optional
and use IT if no DMA channel is specified in the qspi node.

Tested on disco_l475_iot1

Signed-off-by: Erwan Gouriou <erwan.gouriou@linaro.org>

drivers/flash/Kconfig.stm32_qspi

@@ -5,17 +5,18 @@
 # SPDX-License-Identifier: Apache-2.0
 
 DT_COMPAT_ST_STM32_QSPI_NOR := st,stm32-qspi-nor
+DT_STM32_QUADSPI_HAS_DMA := $(dt_node_has_prop,quadspi,dmas)
 
 config FLASH_STM32_QSPI
 	bool "STM32 Quad SPI Flash driver"
 	depends on SOC_FAMILY_STM32
 	default $(dt_compat_enabled,$(DT_COMPAT_ST_STM32_QSPI_NOR))
 	select USE_STM32_HAL_QSPI
-	select USE_STM32_HAL_DMA
-	select DMA
 	select FLASH_HAS_DRIVER_ENABLED
 	select FLASH_JESD216
 	select FLASH_PAGE_LAYOUT
 	select FLASH_HAS_PAGE_LAYOUT
+	select DMA if $(DT_STM32_QUADSPI_HAS_DMA)
+	select USE_STM32_HAL_DMA if $(DT_STM32_QUADSPI_HAS_DMA)
 	help
 	  Enable QSPI-NOR support on the STM32 family of processors.

drivers/flash/flash_stm32_qspi.c

@@ -32,6 +32,8 @@ LOG_MODULE_REGISTER(flash_stm32_qspi, CONFIG_FLASH_LOG_LEVEL);
 #define STM32_QSPI_FIFO_THRESHOLD         8
 #define STM32_QSPI_CLOCK_PRESCALER_MAX  255
 
+#define STM32_QSPI_USE_DMA DT_NODE_HAS_PROP(DT_PARENT(DT_DRV_INST(0)), dmas)
+
 #if DT_HAS_COMPAT_STATUS_OKAY(st_stm32_qspi_nor)
 
 uint32_t table_m_size[] = {
@@ -151,7 +153,11 @@ static int qspi_read_access(const struct device *dev, QSPI_CommandTypeDef *cmd,
 		return -EIO;
 	}
 
+#if STM32_QSPI_USE_DMA
 	hal_ret = HAL_QSPI_Receive_DMA(&dev_data->hqspi, data);
+#else
+	hal_ret = HAL_QSPI_Receive_IT(&dev_data->hqspi, data);
+#endif
 	if (hal_ret != HAL_OK) {
 		LOG_ERR("%d: Failed to read data", hal_ret);
 		return -EIO;
@@ -186,7 +192,11 @@ static int qspi_write_access(const struct device *dev, QSPI_CommandTypeDef *cmd,
 		return -EIO;
 	}
 
+#if STM32_QSPI_USE_DMA
 	hal_ret = HAL_QSPI_Transmit_DMA(&dev_data->hqspi, (uint8_t *)data);
+#else
+	hal_ret = HAL_QSPI_Transmit_IT(&dev_data->hqspi, (uint8_t *)data);
+#endif
 	if (hal_ret != HAL_OK) {
 		LOG_ERR("%d: Failed to read data", hal_ret);
 		return -EIO;
@@ -454,6 +464,7 @@ static void flash_stm32_qspi_isr(const struct device *dev)
 }
 
 /* This function is executed in the interrupt context */
+#if STM32_QSPI_USE_DMA
 static void qspi_dma_callback(const struct device *dev, void *arg,
 			 uint32_t channel, int status)
 {
@@ -466,6 +477,7 @@ static void qspi_dma_callback(const struct device *dev, void *arg,
 
 	HAL_DMA_IRQHandler(hdma);
 }
+#endif
 
 __weak HAL_StatusTypeDef HAL_DMA_Abort_IT(DMA_HandleTypeDef *hdma)
 {
@@ -658,8 +670,6 @@ static int flash_stm32_qspi_init(const struct device *dev)
 {
 	const struct flash_stm32_qspi_config *dev_cfg = DEV_CFG(dev);
 	struct flash_stm32_qspi_data *dev_data = DEV_DATA(dev);
-	struct dma_config dma_cfg = dev_data->dma.cfg;
-	static DMA_HandleTypeDef hdma;
 	uint32_t ahb_clock_freq;
 	uint32_t prescaler = 0;
 	int ret;
@@ -673,6 +683,7 @@ static int flash_stm32_qspi_init(const struct device *dev)
 		return ret;
 	}
 
+#if STM32_QSPI_USE_DMA
 	/*
 	 * DMA configuration
 	 * Due to use of QSPI HAL API in current driver,
@@ -681,7 +692,6 @@ static int flash_stm32_qspi_init(const struct device *dev)
 	 * the minimum information to inform the DMA slot will be in used and
 	 * how to route callbacks.
 	 */
-
 	struct dma_config dma_cfg = dev_data->dma.cfg;
 	static DMA_HandleTypeDef hdma;
 
@@ -691,6 +701,8 @@ static int flash_stm32_qspi_init(const struct device *dev)
 			LOG_ERR("%s device not found", dev_data->dma.name);
 			return -ENODEV;
 		}
+	} else {
+		return -EINVAL;
 	}
 
 	/* Proceed to the minimum Zephyr DMA driver init */
@@ -738,6 +750,8 @@ static int flash_stm32_qspi_init(const struct device *dev)
 	__HAL_LINKDMA(&dev_data->hqspi, hdma, hdma);
 	HAL_DMA_Init(&hdma);
 
+#endif /* STM32_QSPI_USE_DMA */
+
 	/* Clock configuration */
 	__ASSERT_NO_MSG(device_get_binding(STM32_CLOCK_CONTROL_NAME));
 
@@ -762,7 +776,6 @@ static int flash_stm32_qspi_init(const struct device *dev)
 		}
 	}
 	__ASSERT_NO_MSG(prescaler <= STM32_QSPI_CLOCK_PRESCALER_MAX);
-
 	/* Initialize QSPI HAL */
 	dev_data->hqspi.Init.ClockPrescaler = prescaler;
 	dev_data->hqspi.Init.FlashSize = find_lsb_set(dev_cfg->flash_size);

dts/bindings/qspi/st,stm32-qspi.yaml

@@ -30,19 +30,17 @@ properties:
       required: true
 
     dmas:
-      required: true
       description: |
-        DMA channel specifier. Specifier will have a phandle
+        Optional DMA channel specifier. If DMA should be used, specifier should
-        reference to the dma controller, the channel number, the slot number,
+        hold a phandle reference to the dma controller, the channel number,
-        channel configuration and finally features.
+        the slot number, channel configuration and finally features.
 
         For example dmas for TX/RX on QSPI
            dmas = <&dma1 5 5 0x0000 0x03>;
 
     dma-names:
-      required: true
       description: |
-        DMA channel name. Expected value "tx_rx".
+        DMA channel name. If DMA should be used, expected value is "tx_rx".
 
         For example
            dma-names = "tx_rx";