[PATCH v2 3/8] spi: dt-bindings: Add support for selecting data transfer mode

Viken Dadhaniya
2025-01-24T10:53:29Z

Data transfer mode is fixed by TrustZone (TZ), which currently restricts
developers from modifying the transfer mode from the APPS side.

Document the 'qcom,xfer-mode' properties to select the data transfer mode,
either GPI DMA (Generic Packet Interface) or non-GPI mode (PIO/CPU DMA).

SPI controller can operate in one of two modes based on the
'qcom,xfer-mode' property, and the firmware is loaded accordingly.

Co-developed-by: Mukesh Kumar Savaliya <quic_msavaliy@quicinc.com>
Signed-off-by: Mukesh Kumar Savaliya <quic_msavaliy@quicinc.com>
Signed-off-by: Viken Dadhaniya <quic_vdadhani@quicinc.com>
---

v1 -> v2:

- Drop 'qcom,load-firmware' property and add 'firmware-name' property in
qup common driver.
- Update commit log.

v1 Link: https://lore.kernel.org/linux-kernel/20241204150326.1470749-3-quic_vdadhani@quicinc.com/
---
---
.../devicetree/bindings/spi/qcom,spi-geni-qcom.yaml | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/Documentation/devicetree/bindings/spi/qcom,spi-geni-qcom.yaml b/Documentation/devicetree/bindings/spi/qcom,spi-geni-qcom.yaml
index 2e20ca313ec1..d0dd960ee12f 100644
--- a/Documentation/devicetree/bindings/spi/qcom,spi-geni-qcom.yaml
+++ b/Documentation/devicetree/bindings/spi/qcom,spi-geni-qcom.yaml
@@ -66,6 +66,12 @@ properties:
reg:
maxItems: 1

+ qcom,xfer-mode:
+ description: Set the value to 1 for non-GPI (FIFO/CPU DMA) mode and 3 for GPI DMA mode.
+ The default mode is FIFO.
+ $ref: /schemas/types.yaml#/definitions/uint32
+ enum: [1, 3]
+
required:
- compatible
- clocks
@@ -97,6 +103,7 @@ examples:
interconnects = <&qup_virt MASTER_QUP_CORE_0 0 &qup_virt SLAVE_QUP_CORE_0 0>,
<&gem_noc MASTER_APPSS_PROC 0 &config_noc SLAVE_QUP_0 0>;
interconnect-names = "qup-core", "qup-config";
+ qcom,xfer-mode = <1>;
};

- |
--
2.34.1