[PATCH 1/2] spi: Add dt-bindings schema for Cadence XSPI controller driver

Konrad Kociolek
2020-01-20T12:54:31Z

Add dt-bindings documentation for Cadence XSPI controller to support
SPI based flash memories.

Signed-off-by: Konrad Kociolek <konrad@cadence.com>
---
.../devicetree/bindings/spi/cdns,xspi.yaml | 164 +++++++++++++++++++++
1 file changed, 164 insertions(+)
create mode 100644 Documentation/devicetree/bindings/spi/cdns,xspi.yaml

diff --git a/Documentation/devicetree/bindings/spi/cdns,xspi.yaml b/Documentation/devicetree/bindings/spi/cdns,xspi.yaml
new file mode 100644
index 0000000..2d6a362
--- /dev/null
+++ b/Documentation/devicetree/bindings/spi/cdns,xspi.yaml
@@ -0,0 +1,164 @@
+# SPDX-License-Identifier: (GPL-2.0)
+# Copyright 2020 Cadence
+%YAML 1.2
+---
+$id: "http://devicetree.org/schemas/spi/cadence,xspi.yaml#"
+$schema: "http://devicetree.org/meta-schemas/core.yaml#"
+
+title: Cadence XSPI Controller
+
+maintainers:
+ - Konrad Kociolek <konrad@cadence.com>
+
+description: |
+ The XSPI controller allows SPI protocol communication in
+ single, dual, quad or octal wire transmission modes for
+ read/write access to slaves such as SPI-NOR flash.
+
+properties:
+ compatible:
+ const: cdns,xspi-nor-fpga
+
+ reg:
+ maxItems: 3
+ description: |
+ Contains three entries, each of which is a tuple consisting of a
+ physical address and length. The first entry is the address and
+ length of the controller register set. The second entry is the
+ address and length of the Slave DMA data port. The third entry is
+ the address and length of auxiliary registers.
+
+ interrupts:
+ maxItems: 1
+
+ cdns,dqs-last-data-drop:
+ type: boolean
+ description: |
+ This parameter should be set when the Flash Device being used
+ issues data on negative edge of Flash clock and returns them with
+ DQS and the PHY is configured to sample data in DQS mode.
+ If this param is set the controller internally requests this redundant
+ data at the end of the transfer cleaning up the PHY FIFO.
+
+ cdns,phy-data-select-oe-start:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: |
+ Adjusts the starting point of the DQ pad output enable window.
+ Lower numbers pull the rising edge earlier in time and larger
+ numbers cause the rising edge to be delayed. Each bit changes
+ the output enable time by a 1/2 cycle resolution.
+
+ cdns,phy-data-select-oe-end:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: |
+ Adjusts the ending point of the DQ pad output enable window.
+ Lower numbers pull the falling edge earlier in time and larger
+ numbers cause the falling edge to be delayed. Each bit changes
+ the output enable time by a 1/2 cycle resolution.
+
+ cdns,phy-dqs-select-oe-start:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: |
+ Adjusts the starting point of the DQS pad output enable window.
+ Lower numbers pull the rising edge earlier in time and larger
+ numbers cause the rising edge to be delayed. Each bit changes
+ the output enable time by a 1/2 cycle resolution.
+
+ cdns,phy-dqs-select-oe-end:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: |
+ Adjusts the ending point of the DQS pad output enable window.
+ Lower numbers pull the falling edge earlier in time and larger
+ numbers cause the falling edge to be delayed. Each bit changes
+ the output enable time by a 1/2 cycle resolution.
+
+ cdns,phy-gate-cfg-close:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: |
+ Normally the gate is closing then all bits of dfi_cebar are high
+ or when dfi_rd_pre_post_amble and rebar_dfi are high. This parameter
+ allows to extend the closing of the DQS gate. Recommended zero.
+
+ cdns,phy-gate-cfg:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: |
+ Coarse adjust of gate open time. This value is the number of cycles
+ to delay the dfi_rddata_en signal prior to opening the gate in
+ full cycle increments. Decreasing this value pulls the gate earlier
+ in time. This field should be programmed such that the gate signal
+ lands in the valid DQS gate window.
+
+ cdns,phy-rd-del-select:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: |
+ Defines the read data delay. Holds the number of cycles to delay
+ the dfi_rddata_en signal prior to enabling the read FIFO.
+ After this delay, the read pointers begin incrementing the read FIFO.
+
+ cdns,phy-clk-wr-delay:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: |
+ Controls the clk_wr delay line which adjusts the write DQ bit
+ timing in 1/256th steps of the clock period in normal DLL
+ locked mode. In bypass mode this field directly programs
+ the number of delay elements.
+
+ cdns,phy-use-lpbk-dqs:
+ type: boolean
+ description: |
+ This parameter chooses lpbk_dqs to capture data for reads.
+ Instead memory DQS will be used.
+
+ cdns,phy-use-ext-lpbk-dqs:
+ type: boolean
+ description: |
+ This parameter chooses external lpbk_dqs for data capture
+ (lpbk_dqs connected to the lpbk_dqs_IO pad). When not used
+ mem_rebar_pad is used for data read capture.
+
+required:
+ - compatible
+ - reg
+ - interrupts
+ - cdns,phy-data-select-oe-start
+ - cdns,phy-data-select-oe-end
+ - cdns,phy-dqs-select-oe-start
+ - cdns,phy-dqs-select-oe-end
+ - cdns,phy-gate-cfg-close
+ - cdns,phy-gate-cfg
+ - cdns,phy-rd-del-select
+ - cdns,phy-clk-wr-delay
+
+examples:
+ - |
+ xspi: spi@a0010000 {
+ #address-cells = <1>;
+ #size-cells = <0>;
+ compatible = "cdns,xspi-nor-fpga";
+ reg = <0x0 0xa0010000 0x0 0x10000>,
+ <0x0 0xb0000000 0x0 0x10000>,
+ <0x0 0xa0020000 0x0 0x10000>;
+ interrupts = <0 90 IRQ_TYPE_LEVEL_HIGH>;
+ interrupt-parent = <&gic>;
+ cdns,dqs-last-data-drop;
+ cdns,phy-data-select-oe-start = <0>;
+ cdns,phy-data-select-oe-end = <4>;
+ cdns,phy-dqs-select-oe-start = <0>;
+ cdns,phy-dqs-select-oe-end = <1>;
+ cdns,phy-gate-cfg-close = <3>;
+ cdns,phy-gate-cfg = <0>;
+ cdns,phy-rd-del-select = <5>;
+ cdns,phy-clk-wr-delay = <64>;
+ cdns,phy-use-lpbk-dqs;
+ cdns,phy-use-ext-lpbk-dqs;
+ mt35xu512@0 {
+ compatible = "spi-nor", "micron,mt35xu512";
+ spi-max-frequency = <75000000>;
+ reg = <0>;
+ };
+ mt35xu512@1 {
+ compatible = "spi-nor", "micron,mt35xu512";
+ spi-max-frequency = <75000000>;
+ reg = <1>;
+ };
+ };
--
2.7.4