drivers: i2s: add sai support for stm32h7xx

Define SAI1 node for STM32H7xx series.
Add STM32H7xx related DMA configs.
Enable samples/drivers/i2s/output for nucleo_h745zi_q/m7

Signed-off-by: Mario Paja <mariopaja@hotmail.com>

Author: mariopaja

drivers/i2s/i2s_stm32_sai.c

@@ -276,15 +276,42 @@ static int i2s_stm32_sai_dma_init(const struct device *dev)
 	/* HACK: This field is used to inform driver that it is overridden */
 	dma_cfg.linked_channel = STM32_DMA_HAL_OVERRIDE;
 
-	/* Because of the STREAM OFFSET, the DMA channel given here is from 1 -  */
-	ret = dma_config(stream->dma_dev, stream->dma_channel, &dma_cfg);
+	/* Because of the STREAM OFFSET, the DMA channel given here is from 1 - 8 */
+	ret = dma_config(stream->dma_dev, stream->dma_channel + STM32_DMA_STREAM_OFFSET, &dma_cfg);
 
 	if (ret != 0) {
 		LOG_ERR("Failed to configure DMA channel %d",
 			stream->dma_channel + STM32_DMA_STREAM_OFFSET);
 		return ret;
 	}
 
+#if defined(CONFIG_SOC_SERIES_STM32H7X)
+
+	hdma->Instance = __LL_DMA_GET_STREAM_INSTANCE(stream->reg, stream->dma_channel);
+	hdma->Init.Request = dma_cfg.dma_slot;
+	hdma->Init.PeriphDataAlignment = DMA_PDATAALIGN_HALFWORD;
+	hdma->Init.MemDataAlignment = DMA_PDATAALIGN_HALFWORD;
+	hdma->Init.Mode = DMA_NORMAL;
+	hdma->Init.Priority = DMA_PRIORITY_HIGH;
+	hdma->Init.FIFOMode = DMA_FIFOMODE_DISABLE;
+
+	if (stream->dma_cfg.channel_direction == (enum dma_channel_direction)MEMORY_TO_PERIPHERAL) {
+		hdma->Init.Direction = DMA_MEMORY_TO_PERIPH;
+		hdma->Init.PeriphInc = DMA_PINC_DISABLE;
+		hdma->Init.MemInc = DMA_MINC_ENABLE;
+		__HAL_LINKDMA(hsai, hdmatx, dev_data->hdma);
+	} else {
+		hdma->Init.Direction = DMA_PERIPH_TO_MEMORY;
+		hdma->Init.PeriphInc = DMA_PINC_ENABLE;
+		hdma->Init.MemInc = DMA_MINC_DISABLE;
+		__HAL_LINKDMA(hsai, hdmarx, dev_data->hdma);
+	}
+
+	if (HAL_DMA_Init(&dev_data->hdma) != HAL_OK) {
+		LOG_ERR("HAL_DMA_Init: <FAILED>");
+		return -EIO;
+	}
+#else
 	hdma->Instance = LL_DMA_GET_CHANNEL_INSTANCE(stream->reg, stream->dma_channel);
 	hdma->Init.Request = dma_cfg.dma_slot;
 	hdma->Init.BlkHWRequest = DMA_BREQ_SINGLE_BURST;
@@ -318,6 +345,7 @@ static int i2s_stm32_sai_dma_init(const struct device *dev)
 		LOG_ERR("HAL_DMA_ConfigChannelAttributes: <Failed>");
 		return -EIO;
 	}
+#endif
 
 	return 0;
 }

dts/arm/st/h7/stm32h7.dtsi

@@ -3,6 +3,7 @@
  * Copyright (c) 2019 Centaur Analytics, Inc
  * Copyright (c) 2020 Teslabs Engineering S.L.
  * Copyright (c) 2024 STMicroelectronics
+ * Copyright (c) 2025 ZAL Zentrum für Angewandte Luftfahrtforschung GmbH
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -1091,6 +1092,28 @@
 				STM32_DMA_PRIORITY_HIGH) STM32_DMA_FIFO_1_4>;
 			status = "disabled";
 		};
+
+		sai1_a: sai1@40015804 {
+			compatible = "st,stm32-sai";
+			#address-cells = <1>;
+			#size-cells = <0>;
+			reg = <0x40015804 0x20>;
+			clocks = <&rcc STM32_CLOCK(APB2, 22)>,
+				 <&rcc STM32_SRC_PLL2_P SAI1_SEL(1)>;
+			dmas = <&dma1 1 87 0 0>;
+			status = "disabled";
+		};
+
+		sai1_b: sai1@40015824 {
+			compatible = "st,stm32-sai";
+			#address-cells = <1>;
+			#size-cells = <0>;
+			reg = <0x40015824 0x20>;
+			clocks = <&rcc STM32_CLOCK(APB2, 22)>,
+				 <&rcc STM32_SRC_PLL2_P SAI1_SEL(1)>;
+			dmas = <&dma1 0 88 0 0>;
+			status = "disabled";
+		};
 	};
 
 	die_temp: dietemp {

samples/drivers/i2s/output/boards/nucleo_h745zi_q_stm32h745xx_m7.conf

@@ -0,0 +1 @@
+CONFIG_HEAP_MEM_POOL_SIZE=4192

samples/drivers/i2s/output/boards/nucleo_h745zi_q_stm32h745xx_m7.overlay

@@ -0,0 +1,41 @@
+/*
+* Copyright (c) 2025 ZAL Zentrum für Angewandte Luftfahrtforschung GmbH
+* Copyright (c) 2025 Mario Paja
+*
+* SPDX-License-Identifier: Apache-2.0
+*/
+
+/ {
+	aliases {
+		i2s-tx = &sai1_b;
+	};
+};
+
+&pll2 {
+	/* 44.1KHz (0.03% Error) */
+	div-m = <8>;
+	mul-n = <192>;
+	div-q = <2>;
+	div-r = <2>;
+	div-p = <17>;
+	clocks = <&clk_hse>;
+	status = "okay";
+};
+
+&sai1_b {
+	pinctrl-0 = <&sai1_mclk_b_pf7 &sai1_sd_b_pe3
+		 &sai1_fs_b_pf9 &sai1_sck_b_pf8>;
+	pinctrl-names = "default";
+	status = "okay";
+	mclk-enable;
+	mclk-divider = "div-256";
+	dma-names = "tx";
+};
+
+&dmamux1{
+	status = "okay";
+};
+
+&dma1{
+	status = "okay";
+};