[PATCH 02/16] dt-bindings: spi: Add bcmbca-hsspi controller support

From: William Zhang
Date: Fri Jan 06 2023 - 15:19:44 EST


The new Broadcom Broadband BCMBCA SoCs includes a updated HSSPI
controller. Add a new compatible string and required fields for the new
driver. Also add myself and Kursad as the maintainers.

Signed-off-by: William Zhang <william.zhang@xxxxxxxxxxxx>
---

.../bindings/spi/brcm,bcm63xx-hsspi.yaml | 84 +++++++++++++++++--
1 file changed, 78 insertions(+), 6 deletions(-)

diff --git a/Documentation/devicetree/bindings/spi/brcm,bcm63xx-hsspi.yaml b/Documentation/devicetree/bindings/spi/brcm,bcm63xx-hsspi.yaml
index 45f1417b1213..56e69d4a1faf 100644
--- a/Documentation/devicetree/bindings/spi/brcm,bcm63xx-hsspi.yaml
+++ b/Documentation/devicetree/bindings/spi/brcm,bcm63xx-hsspi.yaml
@@ -4,22 +4,51 @@
$id: http://devicetree.org/schemas/spi/brcm,bcm63xx-hsspi.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#

-title: Broadcom BCM6328 High Speed SPI controller
+title: Broadcom Broadband SoC High Speed SPI controller

maintainers:
+
+ - William Zhang <william.zhang@xxxxxxxxxxxx>
+ - Kursad Oney <kursad.oney@xxxxxxxxxxxx>
- Jonas Gorski <jonas.gorski@xxxxxxxxx>

+description: |
+ Broadcom Broadband SoC supports High Speed SPI master controller since the
+ early MIPS based chips such as BCM6328 and BCM63268. This controller was
+ carried over to recent ARM based chips, such as BCM63138, BCM4908 and BCM6858.
+
+ It 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. This controller uses the compatible string brcm,bcm6328-hsspi.
+
+ The newer SoCs such as BCM6756, BCM4912 and BCM6855 include an updated SPI
+ controller that add the capability to allow the driver to control chip select
+ explicitly. This solves the issue in the old controller. This new controller
+ uses the compatible string brcm,bcmbca-hsspi.
+
properties:
compatible:
- const: brcm,bcm6328-hsspi
+ enum:
+ - brcm,bcm6328-hsspi
+ - brcm,bcmbca-hsspi

reg:
- maxItems: 1
+ items:
+ - description: main registers
+ - description: miscellaneous control registers
+ minItems: 1
+
+ reg-names:
+ items:
+ - const: hsspi
+ - const: spim-ctrl

clocks:
items:
- - description: spi master reference clock
- - description: spi master pll clock
+ - description: SPI master reference clock
+ - description: SPI master pll clock

clock-names:
items:
@@ -29,12 +58,43 @@ properties:
interrupts:
maxItems: 1

+ brcm,use-cs-workaround:
+ $ref: /schemas/types.yaml#/definitions/flag
+ description: |
+ Enable dummy chip select workaround for SPI transfers that can not be
+ supported by the default controller's prepend mode, i.e. delay or cs
+ change needed between SPI transfers.
+
required:
- compatible
- reg
- clocks
- clock-names
- - interrupts
+
+allOf:
+ - $ref: "spi-controller.yaml#"
+ - if:
+ properties:
+ compatible:
+ contains:
+ enum:
+ - brcm,bcm6328-hsspi
+ then:
+ properties:
+ reg:
+ minItems: 1
+ maxItems: 1
+ else:
+ properties:
+ reg:
+ minItems: 2
+ maxItems: 2
+ reg-names:
+ minItems: 2
+ maxItems: 2
+ brcm,use-cs-workaround: false
+ required:
+ - reg-names

unevaluatedProperties: false

@@ -50,3 +110,15 @@ examples:
#address-cells = <1>;
#size-cells = <0>;
};
+ - |
+ spi@ff801000 {
+ compatible = "brcm,bcmbca-hsspi";
+ reg = <0xff801000 0x1000>,
+ <0xff802610 0x4>;
+ reg-names = "hsspi", "spim-ctrl";
+ clocks = <&hsspi>, <&hsspi_pll>;
+ clock-names = "hsspi", "pll";
+ num-cs = <8>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+ };
--
2.37.3