drivers: dma: silabs: modify LDMA driver to handle large dma_block_config

drivers/dma/Kconfig.silabs

@@ -14,7 +14,7 @@ if DMA_SILABS_LDMA
 
 config DMA_MAX_DESCRIPTOR
 	int "Max Number of block_config (LDMA_Descriptor)"
-	default 8
+	default 16
 	help
 	  Max Number of block_config (LDMA_Descriptor)
 

drivers/dma/dma_silabs_ldma.c

@@ -89,9 +89,12 @@ static int dma_silabs_get_blocksize(uint32_t src_blen, uint32_t dst_blen, uint32
 
 static int dma_silabs_block_to_descriptor(struct dma_config *config,
 					  struct dma_silabs_channel *chan_conf,
-					  struct dma_block_config *block, LDMA_Descriptor_t *desc)
+					  struct dma_block_config *block, LDMA_Descriptor_t *desc,
+					  int *offset)
 {
-	int ret, src_size, xfer_count;
+	int ret, src_size, xfer_count, loc_offset, mod, rem_bsize;
+
+	loc_offset = *offset;
 
 	if (block->dest_scatter_count || block->source_gather_count ||
 	    block->source_gather_interval || block->dest_scatter_interval ||
@@ -123,17 +126,27 @@ static int dma_silabs_block_to_descriptor(struct dma_config *config,
 	src_size = config->source_data_size;
 	desc->xfer.size = LOG2(src_size);
 
-	if (block->block_size % config->source_data_size) {
-		xfer_count = block->block_size / config->source_data_size;
+	if (loc_offset) {
+		rem_bsize = block->block_size - loc_offset * config->source_data_size;
 	} else {
-		xfer_count = block->block_size / config->source_data_size - 1;
+		rem_bsize = block->block_size;
 	}
 
+	xfer_count = rem_bsize / config->source_data_size;
+	mod = rem_bsize % config->source_data_size;
+
 	if (xfer_count > LDMA_DESCRIPTOR_MAX_XFER_SIZE) {
-		return -ENOTSUP;
-	}
+		desc->xfer.xferCnt = LDMA_DESCRIPTOR_MAX_XFER_SIZE - 1;
+		*offset = loc_offset + LDMA_DESCRIPTOR_MAX_XFER_SIZE;
 
-	desc->xfer.xferCnt = xfer_count;
+	} else {
+		if (!mod || xfer_count == LDMA_DESCRIPTOR_MAX_XFER_SIZE) {
+			xfer_count--;
+		}
+
+		desc->xfer.xferCnt = xfer_count;
+		*offset = 0;
+	}
 
 	/* Warning : High LDMA blockSize (high burst) mean a large transfer
 	 *           without LDMA controller re-arbitration.
@@ -195,8 +208,8 @@ static int dma_silabs_block_to_descriptor(struct dma_config *config,
 		LOG_WRN("dest_buffer address is null.");
 	}
 
-	desc->xfer.srcAddr = block->source_address;
-	desc->xfer.dstAddr = block->dest_address;
+	desc->xfer.srcAddr = block->source_address + loc_offset * config->source_data_size;
+	desc->xfer.dstAddr = block->dest_address + loc_offset * config->dest_data_size;
 
 	return 0;
 }
@@ -229,21 +242,22 @@ static int dma_silabs_configure_descriptor(struct dma_config *config, struct dma
 	struct dma_block_config *head_block = config->head_block;
 	struct dma_block_config *block = config->head_block;
 	LDMA_Descriptor_t *desc, *prev_desc;
-	int ret;
+	int ret, offset;
 
 	/* Descriptors configuration
 	 * block refers to user configured block (dma_block_config structure from dma.h)
 	 * desc refers to driver configured block (LDMA_Descriptor_t structure from silabs
 	 * hal)
 	 */
 	prev_desc = NULL;
+	offset = 0;
 	while (block) {
 		ret = sys_mem_blocks_alloc(data->dma_desc_pool, 1, (void **)&desc);
 		if (ret) {
 			goto err;
 		}
 
-		ret = dma_silabs_block_to_descriptor(config, chan_conf, block, desc);
+		ret = dma_silabs_block_to_descriptor(config, chan_conf, block, desc, &offset);
 		if (ret) {
 			goto err;
 		}
@@ -257,13 +271,15 @@ static int dma_silabs_configure_descriptor(struct dma_config *config, struct dma
 		}
 
 		prev_desc = desc;
-		block = block->next_block;
-		if (block == head_block) {
-			block = NULL;
-			prev_desc->xfer.linkAddr =
-				LDMA_DESCRIPTOR_LINKABS_ADDR_TO_LINKADDR(chan_conf->desc);
-			prev_desc->xfer.linkMode = ldmaLinkModeAbs;
-			prev_desc->xfer.link = 1;
+		if (!offset) {
+			block = block->next_block;
+			if (block == head_block) {
+				block = NULL;
+				prev_desc->xfer.linkAddr =
+					LDMA_DESCRIPTOR_LINKABS_ADDR_TO_LINKADDR(chan_conf->desc);
+				prev_desc->xfer.linkMode = ldmaLinkModeAbs;
+				prev_desc->xfer.link = 1;
+			}
 		}
 	}
 
@@ -525,7 +541,9 @@ int silabs_ldma_append_block(const struct device *dev, uint32_t channel, struct
 	struct dma_block_config *block_config = config->head_block;
 	LDMA_Descriptor_t *desc = data->dma_chan_table[channel].desc;
 	unsigned int key;
-	int ret;
+	int ret, offset;
+
+	offset = 0;
 
 	__ASSERT(!((uintptr_t)desc & ~_LDMA_CH_LINK_LINKADDR_MASK),
 		 "DMA Descriptor is not 32 bits aligned");
@@ -552,9 +570,15 @@ int silabs_ldma_append_block(const struct device *dev, uint32_t channel, struct
 		return -EINVAL;
 	}
 
-	ret = dma_silabs_block_to_descriptor(config, chan_conf, block_config, desc);
+	ret = dma_silabs_block_to_descriptor(config, chan_conf, block_config, desc, &offset);
 	if (ret) {
 		return ret;
+	} else if (offset) {
+		/* If the offset is not 0, it means that the block size is larger than the transfer
+		 * capacity of a single hardware LDMA descriptor. It is not supported with the
+		 * append function.
+		 */
+		return -EINVAL;
 	}
 
 	key = irq_lock();

tests/drivers/dma/loop_transfer/boards/sltb010a.conf

@@ -1,5 +1,4 @@
 # Copyright (c) 2024 Silicon Laboratories, Inc.
 # SPDX-License-Identifier: Apache-2.0
 
-CONFIG_DMA_LOOP_TRANSFER_CHANNEL_NR=0
 CONFIG_DMA_LOOP_TRANSFER_SIZE=2048

tests/drivers/dma/scatter_gather/boards/sltb010a.conf

@@ -1,5 +1,4 @@
 # Copyright (c) 2024 Silicon Laboratories, Inc.
 # SPDX-License-Identifier: Apache-2.0
 
-CONFIG_DMA_SG_CHANNEL_NR=0
 CONFIG_DMA_SG_XFER_SIZE=4096