[PATCH v7 0/3] spi: support the SpacemiT K1 SPI controller

[PATCH v7 0/3] spi: support the SpacemiT K1 SPI controller

[Alex Elder]

This series adds support for the SPI controller found in the SpacemiT
K1 SoC.  The driver currently supports only master mode.  The controller
has two 32-entry FIFOs and supports PIO and DMA for transfers.

Version 7 fixes two bugs, and now builds the driver as a kernel module
by default.

(Note, this is a distinct series from the QSPI driver, which was
merged recently.)

                                        -Alex

This series is available here:
  https://github.com/riscstar/linux/tree/outgoing/spi-v7

Between version 6 and version 7:
  - DIV_ROUND_UP_ULL() is now used when setting the speed, to address
    two errors reported by the Intel kernel test robot on 32-bit builds
  - Fixed a bug interpreting the resource pointer in k1_spi_dma_cleanup()
  - The driver is now built as a module by default, if ARCH_SPACEMIT
    is defined

Here is version 6 of this series:
  https://lore.kernel.org/lkml/20251027125504.297033-1-elder@riscstar.com/

Between version 5 and version 6:
  - Rebase only

Here is version 5 of this series:
  https://lore.kernel.org/lkml/20251013123309.2252042-1-elder@riscstar.com/

Between version 4 and version 5:
  - Added Yixun's Reviewed-by tag on patch 3

Here is version 4 of this series:
  https://lore.kernel.org/lkml/20250925121714.2514932-1-elder@riscstar.com/

Between version 3 and version 4 (all suggested by Yixun):
  - Fixed an underrun/overrun comment error
  - Renamed a pinctrl node
  - Formatted dmas and dma-names properties on one line

Here is version 3 of this series:
  https://lore.kernel.org/lkml/20250922161717.1590690-1-elder@riscstar.com/

Between version 2 and version 3:
  - Add Conor's Acked-by to patch 1
  - Add Rob's Reviewed-by to patch 1
  - Added imply_PDMA to the SPI_SPACEMIT_K1 Kconfig option
  - Fixed a bug pointed out by Vivian (and Troy) in word-sized reads
  - Added a comment stating we use 1, 2, or 4 bytes per word
  - Cleaned up DMA channels properly in case of failure setting up
  - No longer use devm_*() for allocating DMA channels or buffer
  - Moved the SPI controller into the dma-bus memory region

Here is version 2 of this series:
  https://lore.kernel.org/lkml/20250919155914.935608-1-elder@riscstar.com/

Between version 1 and version 2:
  - Use enum rather than const for the binding compatible string
  - Omit the label and status property in the binding example
  - The spi-spacemit-k1.o make target is now added in sorted order
  - The SPI_SPACEMIT_K1 config option is added in sorted order
  - The SPI_SPACEMIT_K1 config does *not* depend on MMP_PDMA,
    however MMP_PDMA is checked at runtime, and if not enabled,
    DMA will not be used
  - Read/modify/writes of registers no longer use an additional
    "virt" variable to hold the address accessed
  - The k1_spi_driver_data->ioaddr field has been renamed base
  - The DMA address for the base address is maintained, rather than
    saving the DMA address of the data register
  - The spi-max-frequency property value is now bounds checked
  - A local variable is now initialized to 0 in k1_spi_write_word()
  - The driver name is now "k1-spi"
  - DT aliases are used rather than spacemit,k1-ssp-id for bus number
  - The order of two pin control properties was changed as requested
  - Clock names and DMA names are now on one line in the "k1.dtsi"
  - The interrupts property is used rather than interrupts-extended
  - The order of two pin control properties was changed as requested
  - Clock names and DMA names are now on one line in the "k1.dtsi"
  - The interrupts property is used rather than interrupts-extended

Here is version 1 of this series:
  https://lore.kernel.org/lkml/20250917220724.288127-1-elder@riscstar.com/


Alex Elder (3):
  dt-bindings: spi: add SpacemiT K1 SPI support
  spi: spacemit: introduce SpacemiT K1 SPI controller driver
  riscv: dts: spacemit: define a SPI controller node

 .../bindings/spi/spacemit,k1-spi.yaml         |  84 ++
 .../boot/dts/spacemit/k1-bananapi-f3.dts      |   7 +
 arch/riscv/boot/dts/spacemit/k1-pinctrl.dtsi  |  20 +
 arch/riscv/boot/dts/spacemit/k1.dtsi          |  15 +
 drivers/spi/Kconfig                           |   9 +
 drivers/spi/Makefile                          |   1 +
 drivers/spi/spi-spacemit-k1.c                 | 966 ++++++++++++++++++
 7 files changed, 1102 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/spi/spacemit,k1-spi.yaml
 create mode 100644 drivers/spi/spi-spacemit-k1.c


base-commit: 0f2995693867bfb26197b117cd55624ddc57582f
-- 
2.48.1

[PATCH v7 1/3] dt-bindings: spi: add SpacemiT K1 SPI support

[Alex Elder]

Add support for the SPI controller implemented by the SpacemiT K1 SoC.

Acked-by: Conor Dooley <conor.dooley@microchip.com>
Acked-by: Troy Mitchell <troy.mitchell@linux.spacemit.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Alex Elder <elder@riscstar.com>
---
 .../bindings/spi/spacemit,k1-spi.yaml         | 84 +++++++++++++++++++
 1 file changed, 84 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/spi/spacemit,k1-spi.yaml

diff --git a/Documentation/devicetree/bindings/spi/spacemit,k1-spi.yaml b/Documentation/devicetree/bindings/spi/spacemit,k1-spi.yaml
new file mode 100644
index 0000000000000..e82c7f8d0b981
--- /dev/null
+++ b/Documentation/devicetree/bindings/spi/spacemit,k1-spi.yaml
@@ -0,0 +1,84 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/spi/spacemit,k1-spi.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: SpacemiT K1 SoC Serial Peripheral Interface (SPI)
+
+maintainers:
+  - Alex Elder <elder@kernel.org>
+
+description:
+  The SpacemiT K1 SoC implements a SPI controller that has two 32-entry
+  FIFOs, for transmit and receive.  Details are currently available in
+  section 18.2.1 of the K1 User Manual, found in the SpacemiT Keystone
+  K1 Documentation[1].  The controller transfers words using PIO.  DMA
+  transfers are supported as well, if both TX and RX DMA channels are
+  specified,
+
+  [1] https://developer.spacemit.com/documentation
+
+allOf:
+  - $ref: /schemas/spi/spi-controller.yaml#
+
+properties:
+  compatible:
+    const: spacemit,k1-spi
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    items:
+      - description: Core clock
+      - description: Bus clock
+
+  clock-names:
+    items:
+      - const: core
+      - const: bus
+
+  resets:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  dmas:
+    items:
+      - description: RX DMA channel
+      - description: TX DMA channel
+
+  dma-names:
+    items:
+      - const: rx
+      - const: tx
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - clock-names
+  - resets
+  - interrupts
+
+unevaluatedProperties: false
+
+examples:
+  - |
+
+    #include <dt-bindings/clock/spacemit,k1-syscon.h>
+    spi@d401c000 {
+        compatible = "spacemit,k1-spi";
+        reg = <0xd401c000 0x30>;
+        #address-cells = <1>;
+        #size-cells = <0>;
+        clocks = <&syscon_apbc CLK_SSP3>,
+                 <&syscon_apbc CLK_SSP3_BUS>;
+        clock-names = "core", "bus";
+        resets = <&syscon_apbc RESET_SSP3>;
+        interrupts = <55>;
+        dmas = <&pdma 20>, <&pdma 19>;
+        dma-names = "rx", "tx";
+    };
-- 
2.48.1

[PATCH v7 3/3] riscv: dts: spacemit: define a SPI controller node

[Alex Elder]

Define a node for the fourth SoC SPI controller (number 3) on the
SpacemiT K1 SoC.

Enable it on the Banana Pi BPI-F3 board, which exposes this feature
via its GPIO block:
  GPIO PIN 19:  MOSI
  GPIO PIN 21:  MISO
  GPIO PIN 23:  SCLK
  GPIO PIN 24:  SS (inverted)

Define pincontrol configurations for the pins as used on that board.

(This was tested using a GigaDevice GD25Q64E SPI NOR chip.)

Reviewed-by: Yixun Lan <dlan@gentoo.org>
Signed-off-by: Alex Elder <elder@riscstar.com>
---
 .../boot/dts/spacemit/k1-bananapi-f3.dts      |  7 +++++++
 arch/riscv/boot/dts/spacemit/k1-pinctrl.dtsi  | 20 +++++++++++++++++++
 arch/riscv/boot/dts/spacemit/k1.dtsi          | 15 ++++++++++++++
 3 files changed, 42 insertions(+)

diff --git a/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts b/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
index 02f218a16318e..bdbfd04f21853 100644
--- a/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
+++ b/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
@@ -16,6 +16,7 @@ aliases {
 		serial0 = &uart0;
 		i2c2 = &i2c2;
 		i2c8 = &i2c8;
+		spi3 = &spi3;
 	};
 
 	chosen {
@@ -264,6 +265,12 @@ dldo7 {
 	};
 };
 
+&spi3 {
+	pinctrl-0 = <&ssp3_0_cfg>;
+	pinctrl-names = "default";
+	status = "okay";
+};
+
 &uart0 {
 	pinctrl-names = "default";
 	pinctrl-0 = <&uart0_2_cfg>;
diff --git a/arch/riscv/boot/dts/spacemit/k1-pinctrl.dtsi b/arch/riscv/boot/dts/spacemit/k1-pinctrl.dtsi
index e922e05ff856d..9b4f4949412f3 100644
--- a/arch/riscv/boot/dts/spacemit/k1-pinctrl.dtsi
+++ b/arch/riscv/boot/dts/spacemit/k1-pinctrl.dtsi
@@ -537,4 +537,24 @@ pwm14-1-pins {
 			drive-strength = <32>;
 		};
 	};
+
+	ssp3_0_cfg: ssp3-0-cfg {
+		ssp3-0-pins {
+			pinmux = <K1_PADCONF(75, 2)>,	/* SCLK */
+				 <K1_PADCONF(77, 2)>,	/* MOSI  */
+				 <K1_PADCONF(78, 2)>;	/* MISO */
+
+			bias-disable;
+			drive-strength = <19>;
+			power-source = <3300>;
+		};
+
+		ssp3-0-frm-pins {
+			pinmux = <K1_PADCONF(76, 2)>;	/* FRM (frame) */
+
+			bias-pull-up = <0>;
+			drive-strength = <19>;
+			power-source = <3300>;
+		};
+	};
 };
diff --git a/arch/riscv/boot/dts/spacemit/k1.dtsi b/arch/riscv/boot/dts/spacemit/k1.dtsi
index 7818ca4979b6a..cb4016886861e 100644
--- a/arch/riscv/boot/dts/spacemit/k1.dtsi
+++ b/arch/riscv/boot/dts/spacemit/k1.dtsi
@@ -919,6 +919,21 @@ qspi: spi@d420c000 {
 				status = "disabled";
 			};
 
+			spi3: spi@d401c000 {
+				compatible = "spacemit,k1-spi";
+				reg = <0x0 0xd401c000 0x0 0x30>;
+				#address-cells = <1>;
+				#size-cells = <0>;
+				clocks = <&syscon_apbc CLK_SSP3>,
+					 <&syscon_apbc CLK_SSP3_BUS>;
+				clock-names = "core", "bus";
+				resets = <&syscon_apbc RESET_SSP3>;
+				interrupts = <55>;
+				dmas = <&pdma 20>, <&pdma 19>;
+				dma-names = "rx", "tx";
+				status = "disabled";
+			};
+
 			/* sec_uart1: 0xf0612000, not available from Linux */
 		};
 
-- 
2.48.1