[PATCH v4] riscv: dts: spacemit: Use symbolic PDMA request numbers on K1

The PDMA request numbers (DRQ) are fixed values specific to the SoC from
a hardware perspective. The detailed definition can be found in K1 User
Manual [1], Chapter 9.4.3 DMA Connectivity & Assignments. Add a DTS
header file to define the symbolic names for the DRQs of non-secure DMA
peripherals.

Convert the K1 SPI3 node to these macros.

Link: https://www.spacemit.com/community/document/info?lang=en&nodepath=hardware/key_stone/k1/k1_docs/k1_usermanual/9.Top_System.md [1]
Signed-off-by: Guodong Xu <[email protected]>
---
Changes in v4:
- Rework the commit message (Yixun Lan).
- Trim the k1-pdma.h file comment (Yixun Lan).
- Link to v3: https://patch.msgid.link/[email protected]

Changes in v3:
- Move the request-number macros from include/dt-bindings/dma/ to a local
  DTS header arch/riscv/boot/dts/spacemit/k1-pdma.h (Conor).
- Squash the header and its user into a single patch.
- Link to v2: https://patch.msgid.link/[email protected]

Changes in v2:
- Drop the #dma-cells description change in spacemit,k1-pdma.yaml; the request
  numbers are hardware-fixed and unused by the driver (Conor)
- Link to v1: https://patch.msgid.link/[email protected]
---
 arch/riscv/boot/dts/spacemit/k1-pdma.h | 56 ++++++++++++++++++++++++++++++++++
 arch/riscv/boot/dts/spacemit/k1.dtsi   |  4 ++-
 2 files changed, 59 insertions(+), 1 deletion(-)

diff --git a/arch/riscv/boot/dts/spacemit/k1-pdma.h b/arch/riscv/boot/dts/spacemit/k1-pdma.h
new file mode 100644
index 0000000000000..7e5ad3d7111d4
--- /dev/null
+++ b/arch/riscv/boot/dts/spacemit/k1-pdma.h
@@ -0,0 +1,56 @@
+/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */
+/*
+ * DMA request number (DRQ) definitions for non-secure peripherals of
+ * the SpacemiT K1 PDMA.
+ *
+ * Copyright (c) 2026 Guodong Xu <[email protected]>
+ */
+
+#ifndef _DTS_SPACEMIT_K1_PDMA_H
+#define _DTS_SPACEMIT_K1_PDMA_H
+
+#define K1_PDMA_UART0_TX	3
+#define K1_PDMA_UART0_RX	4
+#define K1_PDMA_UART2_TX	5
+#define K1_PDMA_UART2_RX	6
+#define K1_PDMA_UART3_TX	7
+#define K1_PDMA_UART3_RX	8
+#define K1_PDMA_UART4_TX	9
+#define K1_PDMA_UART4_RX	10
+#define K1_PDMA_I2C0_TX		11
+#define K1_PDMA_I2C0_RX		12
+#define K1_PDMA_I2C1_TX		13
+#define K1_PDMA_I2C1_RX		14
+#define K1_PDMA_I2C2_TX		15
+#define K1_PDMA_I2C2_RX		16
+#define K1_PDMA_I2C4_TX		17
+#define K1_PDMA_I2C4_RX		18
+#define K1_PDMA_SPI3_TX		19
+#define K1_PDMA_SPI3_RX		20
+#define K1_PDMA_I2S0_TX		21
+#define K1_PDMA_I2S0_RX		22
+#define K1_PDMA_I2S1_TX		23
+#define K1_PDMA_I2S1_RX		24
+#define K1_PDMA_UART5_TX	25
+#define K1_PDMA_UART5_RX	26
+#define K1_PDMA_UART6_TX	27
+#define K1_PDMA_UART6_RX	28
+#define K1_PDMA_UART7_TX	29
+#define K1_PDMA_UART7_RX	30
+#define K1_PDMA_UART8_TX	31
+#define K1_PDMA_UART8_RX	32
+#define K1_PDMA_UART9_TX	33
+#define K1_PDMA_UART9_RX	34
+#define K1_PDMA_I2C5_TX		35
+#define K1_PDMA_I2C5_RX		36
+#define K1_PDMA_I2C6_TX		37
+#define K1_PDMA_I2C6_RX		38
+#define K1_PDMA_I2C7_TX		39
+#define K1_PDMA_I2C7_RX		40
+#define K1_PDMA_I2C8_TX		41
+#define K1_PDMA_I2C8_RX		42
+#define K1_PDMA_CAN0_RX		43
+#define K1_PDMA_QSPI_RX		44
+#define K1_PDMA_QSPI_TX		45
+
+#endif /* _DTS_SPACEMIT_K1_PDMA_H */
diff --git a/arch/riscv/boot/dts/spacemit/k1.dtsi b/arch/riscv/boot/dts/spacemit/k1.dtsi
index 08a0f28d011fe..7d414e15d2cc2 100644
--- a/arch/riscv/boot/dts/spacemit/k1.dtsi
+++ b/arch/riscv/boot/dts/spacemit/k1.dtsi
@@ -6,6 +6,8 @@
 #include <dt-bindings/clock/spacemit,k1-syscon.h>
 #include <dt-bindings/phy/phy.h>
 
+#include "k1-pdma.h"
+
 /dts-v1/;
 / {
 	#address-cells = <2>;
@@ -1094,7 +1096,7 @@ spi3: spi@d401c000 {
 				clock-names = "core", "bus";
 				resets = <&syscon_apbc RESET_SSP3>;
 				interrupts = <55>;
-				dmas = <&pdma 20>, <&pdma 19>;
+				dmas = <&pdma K1_PDMA_SPI3_RX>, <&pdma K1_PDMA_SPI3_TX>;
 				dma-names = "rx", "tx";
 				status = "disabled";
 			};

---
base-commit: 793cc54475b49b5b558902b5c13e4bfe66530a50
change-id: 20260607-b4-k1-pdma-req-macros-8d276d0126df

Best regards,
--  
Guodong Xu <[email protected]>