Hi Conor,
On 29/08/24 5:46 PM, Conor Dooley wrote:
On Thu, Aug 29, 2024 at 02:32:02PM +0200, Angelo Dureghello wrote:
From: Angelo Dureghello <adureghello@xxxxxxxxxxxx>
Add bus property.
RFC it may be, but you do need to explain what this bus-type actually
describes for commenting on the suitability of the method to be
meaningful.
thanks for the feedbacks,
a "bus" is intended as a generic interface connected to the target,
may be used from a custom IP (fpga) to communicate with the target
device (by read/write(reg and value)) using a special custom interface.
The bus could also be physically the same of some well-known existing
interfaces (as parallel, lvds or other uncommon interfaces), but using
an uncommon/custom protocol over it.
In concrete, actually bus-type is added to the backend since the
ad3552r DAC chip can be connected (for maximum speed) by a 5 lanes DDR
parallel bus (interface that i named QSPI, but it's not exactly a QSPI
as a protocol), so it's a device-specific interface.
With additions in this patchset, other frontends, of course not only
DACs, will be able to add specific busses and read/wrtie to the bus
as needed.
Signed-off-by: Angelo Dureghello <adureghello@xxxxxxxxxxxx>
---
Documentation/devicetree/bindings/iio/dac/adi,axi-dac.yaml | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/Documentation/devicetree/bindings/iio/dac/adi,axi-dac.yaml b/Documentation/devicetree/bindings/iio/dac/adi,axi-dac.yaml
index a55e9bfc66d7..a7ce72e1cd81 100644
--- a/Documentation/devicetree/bindings/iio/dac/adi,axi-dac.yaml
+++ b/Documentation/devicetree/bindings/iio/dac/adi,axi-dac.yaml
@@ -38,6 +38,15 @@ properties:
clocks:
maxItems: 1
You mentioned about new compatible strings, does the one currently
listed in this binding support both bus types?
Making the bus type decision based on compatible only really makes sense
if they're different versions of the IP, but not if they're different
configuration options for a given version.
+ bus-type:
DAC IP on fpga actually respects same structure and register set, except
for a named "custom" register that may use specific bitfields depending
on the application of the IP.
If, as you mentioned, there are multiple bus types, a non-flag property
does make sense. However, I am really not keen on these "forced" numerical
properties at all, I'd much rather see strings used here.
ack, thanks.
Thanks,
Conor.
thanks a lot,
regards,
Angelo
+ maxItems: 1
+ description: |
+ Configure bus type:
+ - 0: none
+ - 1: qspi
+ enum: [0, 1]
+ default: 0
+
'#io-backend-cells':
const: 0
--
2.45.0.rc1
--
,,, Angelo Dureghello
:: :. BayLibre -runtime team- Developer
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