dt-bindings: spi: Add bcm63xx-hsspi controller support

Bring the device tree binding document from Linux to u-boot

Port from linux patches:
Link: https://lore.kernel.org/r/20230207065826.285013-2-william.zhang@broadcom.com
Link: https://lore.kernel.org/r/20230207065826.285013-3-william.zhang@broadcom.com
Signed-off-by: William Zhang <william.zhang@broadcom.com>
Reviewed-by: Jagan Teki <jagan@amarulasolutions.com>

diff --git a/doc/device-tree-bindings/spi/brcm,bcm63xx-hsspi.yaml b/doc/device-tree-bindings/spi/brcm,bcm63xx-hsspi.yaml
new file mode 100644 (file)
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+# SPDX-License-Identifier: GPL-2.0 OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/spi/brcm,bcm63xx-hsspi.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Broadcom Broadband SoC High Speed SPI controller
+
+maintainers:
+  - William Zhang <william.zhang@broadcom.com>
+  - Kursad Oney <kursad.oney@broadcom.com>
+  - Jonas Gorski <jonas.gorski@gmail.com>
+
+description: |
+  Broadcom Broadband SoC supports High Speed SPI master controller since the
+  early MIPS based chips such as BCM6328 and BCM63268.  This initial rev 1.0
+  controller was carried over to recent ARM based chips, such as BCM63138,
+  BCM4908 and BCM6858. The old MIPS based chip should continue to use the
+  brcm,bcm6328-hsspi compatible string. The recent ARM based chip is required to
+  use the brcm,bcmbca-hsspi-v1.0 as part of its compatible string list as
+  defined below to match the specific chip along with ip revision info.
+
+  This rev 1.0 controller has a limitation that can not keep the chip select line
+  active between the SPI transfers within the same SPI message. This can
+  terminate the transaction to some SPI devices prematurely. The issue can be
+  worked around by either the controller's prepend mode or using the dummy chip
+  select workaround. Driver automatically picks the suitable mode based on
+  transfer type so it is transparent to the user.
+
+  The newer SoCs such as BCM6756, BCM4912 and BCM6855 include an updated SPI
+  controller rev 1.1 that add the capability to allow the driver to control chip
+  select explicitly. This solves the issue in the old controller.
+
+properties:
+  compatible:
+    oneOf:
+      - const: brcm,bcm6328-hsspi
+      - items:
+          - enum:
+              - brcm,bcm47622-hsspi
+              - brcm,bcm4908-hsspi
+              - brcm,bcm63138-hsspi
+              - brcm,bcm63146-hsspi
+              - brcm,bcm63148-hsspi
+              - brcm,bcm63158-hsspi
+              - brcm,bcm63178-hsspi
+              - brcm,bcm6846-hsspi
+              - brcm,bcm6856-hsspi
+              - brcm,bcm6858-hsspi
+              - brcm,bcm6878-hsspi
+          - const: brcm,bcmbca-hsspi-v1.0
+      - items:
+          - enum:
+              - brcm,bcm4912-hsspi
+              - brcm,bcm6756-hsspi
+              - brcm,bcm6813-hsspi
+              - brcm,bcm6855-hsspi
+          - const: brcm,bcmbca-hsspi-v1.1
+
+  reg:
+    items:
+      - description: main registers
+      - description: miscellaneous control registers
+    minItems: 1
+
+  reg-names:
+    items:
+      - const: hsspi
+      - const: spim-ctrl
+    minItems: 1
+
+  clocks:
+    items:
+      - description: SPI master reference clock
+      - description: SPI master pll clock
+
+  clock-names:
+    items:
+      - const: hsspi
+      - const: pll
+
+  interrupts:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - clock-names
+  - interrupts
+
+allOf:
+  - $ref: spi-controller.yaml#
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - brcm,bcm6328-hsspi
+              - brcm,bcmbca-hsspi-v1.0
+    then:
+      properties:
+        reg:
+          maxItems: 1
+        reg-names:
+          maxItems: 1
+    else:
+      properties:
+        reg:
+          minItems: 2
+          maxItems: 2
+        reg-names:
+          minItems: 2
+          maxItems: 2
+      required:
+        - reg-names
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    spi@ff801000 {
+        compatible = "brcm,bcm6756-hsspi", "brcm,bcmbca-hsspi-v1.1";
+        reg = <0xff801000 0x1000>,
+              <0xff802610 0x4>;
+        reg-names = "hsspi", "spim-ctrl";
+        interrupts = <GIC_SPI 36 IRQ_TYPE_LEVEL_HIGH>;
+        clocks = <&hsspi>, <&hsspi_pll>;
+        clock-names = "hsspi", "pll";
+        num-cs = <8>;
+        #address-cells = <1>;
+        #size-cells = <0>;
+    };