spi: dw: Add Baikal-T1 SPI Controller bindings
These controllers are based on the DW APB SSI IP-core and embedded into
the SoC, so two of them are equipped with IRQ, DMA, 64 words FIFOs and 4
native CS, while another one as being utilized by the Baikal-T1 System
Boot Controller has got a very limited resources: no IRQ, no DMA, only a
single native chip-select and just 8 bytes Tx/Rx FIFOs available. That's
why we have to mark the IRQ to be optional for the later interface.
The SPI controller embedded into the Baikal-T1 System Boot Controller can
be also used to directly access an external SPI flash by means of a
dedicated FSM. The corresponding MMIO region availability is switchable by
the embedded multiplexor, which phandle can be specified in the dts node.
* We added a new example to test out the non-standard Baikal-T1 System
Boot SPI Controller DT binding.
Co-developed-by: Ramil Zaripov <Ramil.Zaripov@baikalelectronics.ru>
Signed-off-by: Ramil Zaripov <Ramil.Zaripov@baikalelectronics.ru>
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20201007235511.4935-21-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml b/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml
index c79c8a1..99ed9b4 100644
--- a/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml
+++ b/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml
@@ -22,6 +22,21 @@
properties:
reg:
minItems: 2
+ - if:
+ properties:
+ compatible:
+ contains:
+ enum:
+ - baikal,bt1-sys-ssi
+ then:
+ properties:
+ mux-controls:
+ maxItems: 1
+ required:
+ - mux-controls
+ else:
+ required:
+ - interrupts
properties:
compatible:
@@ -46,12 +61,16 @@
- const: snps,dw-apb-ssi
- description: Intel Keem Bay SPI Controller
const: intel,keembay-ssi
+ - description: Baikal-T1 SPI Controller
+ const: baikal,bt1-ssi
+ - description: Baikal-T1 System Boot SPI Controller
+ const: baikal,bt1-sys-ssi
reg:
minItems: 1
items:
- description: DW APB SSI controller memory mapped registers
- - description: SPI MST region map
+ - description: SPI MST region map or directly mapped SPI ROM
interrupts:
maxItems: 1
@@ -129,7 +148,6 @@
- reg
- "#address-cells"
- "#size-cells"
- - interrupts
- clocks
examples:
@@ -151,4 +169,15 @@
rx-sample-delay-ns = <7>;
};
};
+ - |
+ spi@1f040100 {
+ compatible = "baikal,bt1-sys-ssi";
+ reg = <0x1f040100 0x900>,
+ <0x1c000000 0x1000000>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+ mux-controls = <&boot_mux>;
+ clocks = <&ccu_sys>;
+ clock-names = "ssi_clk";
+ };
...
