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-rw-r--r--include/linux/dma/sprd-dma.h190
1 files changed, 190 insertions, 0 deletions
diff --git a/include/linux/dma/sprd-dma.h b/include/linux/dma/sprd-dma.h
new file mode 100644
index 000000000..d09c6f6f6
--- /dev/null
+++ b/include/linux/dma/sprd-dma.h
@@ -0,0 +1,190 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef _SPRD_DMA_H_
+#define _SPRD_DMA_H_
+
+#define SPRD_DMA_REQ_SHIFT 8
+#define SPRD_DMA_TRG_MODE_SHIFT 16
+#define SPRD_DMA_CHN_MODE_SHIFT 24
+#define SPRD_DMA_FLAGS(chn_mode, trg_mode, req_mode, int_type) \
+ ((chn_mode) << SPRD_DMA_CHN_MODE_SHIFT | \
+ (trg_mode) << SPRD_DMA_TRG_MODE_SHIFT | \
+ (req_mode) << SPRD_DMA_REQ_SHIFT | (int_type))
+
+/*
+ * The Spreadtrum DMA controller supports channel 2-stage tansfer, that means
+ * we can request 2 dma channels, one for source channel, and another one for
+ * destination channel. Each channel is independent, and has its own
+ * configurations. Once the source channel's transaction is done, it will
+ * trigger the destination channel's transaction automatically by hardware
+ * signal.
+ *
+ * To support 2-stage tansfer, we must configure the channel mode and trigger
+ * mode as below definition.
+ */
+
+/*
+ * enum sprd_dma_chn_mode: define the DMA channel mode for 2-stage transfer
+ * @SPRD_DMA_CHN_MODE_NONE: No channel mode setting which means channel doesn't
+ * support the 2-stage transfer.
+ * @SPRD_DMA_SRC_CHN0: Channel used as source channel 0.
+ * @SPRD_DMA_SRC_CHN1: Channel used as source channel 1.
+ * @SPRD_DMA_DST_CHN0: Channel used as destination channel 0.
+ * @SPRD_DMA_DST_CHN1: Channel used as destination channel 1.
+ *
+ * Now the DMA controller can supports 2 groups 2-stage transfer.
+ */
+enum sprd_dma_chn_mode {
+ SPRD_DMA_CHN_MODE_NONE,
+ SPRD_DMA_SRC_CHN0,
+ SPRD_DMA_SRC_CHN1,
+ SPRD_DMA_DST_CHN0,
+ SPRD_DMA_DST_CHN1,
+};
+
+/*
+ * enum sprd_dma_trg_mode: define the DMA channel trigger mode for 2-stage
+ * transfer
+ * @SPRD_DMA_NO_TRG: No trigger setting.
+ * @SPRD_DMA_FRAG_DONE_TRG: Trigger the transaction of destination channel
+ * automatically once the source channel's fragment request is done.
+ * @SPRD_DMA_BLOCK_DONE_TRG: Trigger the transaction of destination channel
+ * automatically once the source channel's block request is done.
+ * @SPRD_DMA_TRANS_DONE_TRG: Trigger the transaction of destination channel
+ * automatically once the source channel's transfer request is done.
+ * @SPRD_DMA_LIST_DONE_TRG: Trigger the transaction of destination channel
+ * automatically once the source channel's link-list request is done.
+ */
+enum sprd_dma_trg_mode {
+ SPRD_DMA_NO_TRG,
+ SPRD_DMA_FRAG_DONE_TRG,
+ SPRD_DMA_BLOCK_DONE_TRG,
+ SPRD_DMA_TRANS_DONE_TRG,
+ SPRD_DMA_LIST_DONE_TRG,
+};
+
+/*
+ * enum sprd_dma_req_mode: define the DMA request mode
+ * @SPRD_DMA_FRAG_REQ: fragment request mode
+ * @SPRD_DMA_BLK_REQ: block request mode
+ * @SPRD_DMA_TRANS_REQ: transaction request mode
+ * @SPRD_DMA_LIST_REQ: link-list request mode
+ *
+ * We have 4 types request mode: fragment mode, block mode, transaction mode
+ * and linklist mode. One transaction can contain several blocks, one block can
+ * contain several fragments. Link-list mode means we can save several DMA
+ * configuration into one reserved memory, then DMA can fetch each DMA
+ * configuration automatically to start transfer.
+ */
+enum sprd_dma_req_mode {
+ SPRD_DMA_FRAG_REQ,
+ SPRD_DMA_BLK_REQ,
+ SPRD_DMA_TRANS_REQ,
+ SPRD_DMA_LIST_REQ,
+};
+
+/*
+ * enum sprd_dma_int_type: define the DMA interrupt type
+ * @SPRD_DMA_NO_INT: do not need generate DMA interrupts.
+ * @SPRD_DMA_FRAG_INT: fragment done interrupt when one fragment request
+ * is done.
+ * @SPRD_DMA_BLK_INT: block done interrupt when one block request is done.
+ * @SPRD_DMA_BLK_FRAG_INT: block and fragment interrupt when one fragment
+ * or one block request is done.
+ * @SPRD_DMA_TRANS_INT: tansaction done interrupt when one transaction
+ * request is done.
+ * @SPRD_DMA_TRANS_FRAG_INT: transaction and fragment interrupt when one
+ * transaction request or fragment request is done.
+ * @SPRD_DMA_TRANS_BLK_INT: transaction and block interrupt when one
+ * transaction request or block request is done.
+ * @SPRD_DMA_LIST_INT: link-list done interrupt when one link-list request
+ * is done.
+ * @SPRD_DMA_CFGERR_INT: configure error interrupt when configuration is
+ * incorrect.
+ */
+enum sprd_dma_int_type {
+ SPRD_DMA_NO_INT,
+ SPRD_DMA_FRAG_INT,
+ SPRD_DMA_BLK_INT,
+ SPRD_DMA_BLK_FRAG_INT,
+ SPRD_DMA_TRANS_INT,
+ SPRD_DMA_TRANS_FRAG_INT,
+ SPRD_DMA_TRANS_BLK_INT,
+ SPRD_DMA_LIST_INT,
+ SPRD_DMA_CFGERR_INT,
+};
+
+/*
+ * struct sprd_dma_linklist - DMA link-list address structure
+ * @virt_addr: link-list virtual address to configure link-list node
+ * @phy_addr: link-list physical address to link DMA transfer
+ * @wrap_addr: the wrap address for link-list mode, which means once the
+ * transfer address reaches the wrap address, the next transfer address
+ * will jump to the address specified by wrap_to register.
+ *
+ * The Spreadtrum DMA controller supports the link-list mode, that means slaves
+ * can supply several groups configurations (each configuration represents one
+ * DMA transfer) saved in memory, and DMA controller will link these groups
+ * configurations by writing the physical address of each configuration into the
+ * link-list register.
+ *
+ * Just as shown below, the link-list pointer register will be pointed to the
+ * physical address of 'configuration 1', and the 'configuration 1' link-list
+ * pointer will be pointed to 'configuration 2', and so on.
+ * Once trigger the DMA transfer, the DMA controller will load 'configuration
+ * 1' to its registers automatically, after 'configuration 1' transaction is
+ * done, DMA controller will load 'configuration 2' automatically, until all
+ * DMA transactions are done.
+ *
+ * Note: The last link-list pointer should point to the physical address
+ * of 'configuration 1', which can avoid DMA controller loads incorrect
+ * configuration when the last configuration transaction is done.
+ *
+ * DMA controller linklist memory
+ * ====================== -----------------------
+ *| | | configuration 1 |<---
+ *| DMA controller | ------->| | |
+ *| | | | | |
+ *| | | | | |
+ *| | | | | |
+ *| linklist pointer reg |---- ----| linklist pointer | |
+ * ====================== | ----------------------- |
+ * | |
+ * | ----------------------- |
+ * | | configuration 2 | |
+ * --->| | |
+ * | | |
+ * | | |
+ * | | |
+ * ----| linklist pointer | |
+ * | ----------------------- |
+ * | |
+ * | ----------------------- |
+ * | | configuration 3 | |
+ * --->| | |
+ * | | |
+ * | . | |
+ * . |
+ * . |
+ * . |
+ * | . |
+ * | ----------------------- |
+ * | | configuration n | |
+ * --->| | |
+ * | | |
+ * | | |
+ * | | |
+ * | linklist pointer |----
+ * -----------------------
+ *
+ * To support the link-list mode, DMA slaves should allocate one segment memory
+ * from always-on IRAM or dma coherent memory to store these groups of DMA
+ * configuration, and pass the virtual and physical address to DMA controller.
+ */
+struct sprd_dma_linklist {
+ unsigned long virt_addr;
+ phys_addr_t phy_addr;
+ phys_addr_t wrap_addr;
+};
+
+#endif