Thread (12 messages) 12 messages, 2 authors, 2020-06-19

Re: [PATCH v6 1/9] dt-bindings: dma: dw: Convert DW DMAC to DT binding

From: Andy Shevchenko <hidden>
Date: 2020-06-18 08:22:14
Also in: dmaengine, linux-mips, lkml

On Thu, Jun 18, 2020 at 2:43 AM Serge Semin
[off-list ref] wrote:
Modern device tree bindings are supposed to be created as YAML-files
in accordance with dt-schema. This commit replaces the Synopsis
Designware DMA controller legacy bare text bindings with YAML file.
The only required prorties are "compatible", "reg", "#dma-cells" and
"interrupts", which will be used by the driver to correctly find the
controller memory region and handle its events. The rest of the properties
are optional, since in case if either "dma-channels" or "dma-masters" isn't
specified, the driver will attempt to auto-detect the IP core
configuration.

Signed-off-by: Serge Semin <redacted>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Alexey Malahov <redacted>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: linux-mips@vger.kernel.org

Rob, here are questions to you.
+  dma-channels:
+    description: |
+      Number of DMA channels supported by the controller. In case if
+      not specified the driver will try to auto-detect this and
+      the rest of the optional parameters.
+    minimum: 1
+    maximum: 8
...
+  multi-block:
+      maxItems: 8
This maximum is defined by above dma-channels property. Is there any
way to put it in the schema?

...
+  snps,dma-protection-control:
+    $ref: /schemas/types.yaml#definitions/uint32
+    description: |
+      Bits one-to-one passed to the AHB HPROT[3:1] bus. Each bit setting
+      indicates the following features: bit 0 - privileged mode,
+      bit 1 - DMA is bufferable, bit 2 - DMA is cacheable.
+    default: 0
+    minimum: 0
+    maximum: 7
AFAIR this is defined by bit flags, does schema have a mechanism to
define flags-like entries?

-- 
With Best Regards,
Andy Shevchenko
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