Re: [PATCH v3 04/10] dt-bindings: iio: dac: ad3552r: add io-backend support

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hi Krzysztof,

On 22/09/24 23:02, Krzysztof Kozlowski wrote:
On Thu, Sep 19, 2024 at 11:20:00AM +0200, Angelo Dureghello wrote:
From: Angelo Dureghello <adureghello@xxxxxxxxxxxx>

There is a version AXI DAC IP block (for FPGAs) that provides
a physical bus for AD3552R and similar chips, and acts as
an SPI controller.

For this case, the binding is modified to include some
additional properties.

Signed-off-by: Angelo Dureghello <adureghello@xxxxxxxxxxxx>
---
  .../devicetree/bindings/iio/dac/adi,ad3552r.yaml   | 42 ++++++++++++++++++++++
  1 file changed, 42 insertions(+)

diff --git a/Documentation/devicetree/bindings/iio/dac/adi,ad3552r.yaml b/Documentation/devicetree/bindings/iio/dac/adi,ad3552r.yaml
index 41fe00034742..aca4a41c2633 100644
--- a/Documentation/devicetree/bindings/iio/dac/adi,ad3552r.yaml
+++ b/Documentation/devicetree/bindings/iio/dac/adi,ad3552r.yaml
@@ -60,6 +60,18 @@ properties:
      $ref: /schemas/types.yaml#/definitions/uint32
      enum: [0, 1, 2, 3]
+ io-backends:
+    description: The iio backend reference.
+      An example backend can be found at
+        https://analogdevicesinc.github.io/hdl/library/axi_ad3552r/index.html
+    maxItems: 1
+
+  adi,synchronous-mode:
+    description: Enable waiting for external synchronization signal.
+      Some AXI IP configuration can implement a dual-IP layout, with internal
+      wirings for streaming synchronization.
+    type: boolean
+
    '#address-cells':
      const: 1
@@ -128,6 +140,7 @@ patternProperties:
            - custom-output-range-config
allOf:
+  - $ref: /schemas/spi/spi-peripheral-props.yaml#
    - if:
        properties:
          compatible:
@@ -238,4 +251,33 @@ examples:
              };
          };
      };
+
+  - |
+    axi_dac: spi@44a70000 {
+        compatible = "adi,axi-ad3552r";
That is either redundant or entire example should go to the parent node,
if this device is fixed child of complex device (IOW, adi,ad3552r cannot
be used outside of adi,axi-ad3552r).

ad3552r can still be used by a generic "classic" spi
controller (SCLK/CS/MISO) but at a slower samplerate, fpga
controller only (axi-ad3552r) can reach 33MUPS.


+        reg = <0x44a70000 0x1000>;
+        dmas = <&dac_tx_dma 0>;
+        dma-names = "tx";
+        #io-backend-cells = <0>;
+        clocks = <&ref_clk>;
+
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        dac@0 {
+            compatible = "adi,ad3552r";
+            reg = <0>;
+            reset-gpios = <&gpio0 92 0>;
Use standard defines for GPIO flags.

fixed, thanks

+            io-backends = <&axi_dac>;
Why do you need to point to the parent? How much coupled are these
devices? Child pointing to parent is not usually expected, because
that's obvious.


"io-backends" is actually the way to refer to the backend module,
(used already for i.e. ad9739a),
it is needed because the backend is not only acting as spi-controller,
but is also providing some APIs for synchronization and bus setup support.

Best regards,
Krzysztof

Thanks,
Regards,
Angelo






[Index of Archives]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Input]     [Linux Kernel]     [Linux SCSI]     [X.org]

  Powered by Linux