[1/2] dt-bindings: Create DT bindings for [PS]ATA controllers

Message ID 20191231172458.25984-1-linus.walleij@linaro.org
State New
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  • [1/2] dt-bindings: Create DT bindings for [PS]ATA controllers
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Commit Message

Linus Walleij Dec. 31, 2019, 5:24 p.m.
I need to create subnodes for drives connected to PATA
or SATA host controllers, and this needs to be supported
generally, so create a common YAML binding for
"pata-controller" or "sata-controller" that will support
subnodes with drives.

Cc: Rob Herring <robh+dt@kernel.org>
Cc: devicetree@vger.kernel.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

---
 .../bindings/ata/pata-sata-common.yaml        | 47 +++++++++++++++++++
 1 file changed, 47 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/ata/pata-sata-common.yaml

-- 
2.21.0

Comments

Sergei Shtylyov Dec. 31, 2019, 5:46 p.m. | #1
Hello!

On 12/31/2019 08:24 PM, Linus Walleij wrote:

> I need to create subnodes for drives connected to PATA

> or SATA host controllers, and this needs to be supported

> generally, so create a common YAML binding for

> "pata-controller" or "sata-controller" that will support

> subnodes with drives.

> 

> Cc: Rob Herring <robh+dt@kernel.org>

> Cc: devicetree@vger.kernel.org

> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

> ---

>  .../bindings/ata/pata-sata-common.yaml        | 47 +++++++++++++++++++

>  1 file changed, 47 insertions(+)

>  create mode 100644 Documentation/devicetree/bindings/ata/pata-sata-common.yaml

> 

> diff --git a/Documentation/devicetree/bindings/ata/pata-sata-common.yaml b/Documentation/devicetree/bindings/ata/pata-sata-common.yaml

> new file mode 100644

> index 000000000000..d94aa20a29e3

> --- /dev/null

> +++ b/Documentation/devicetree/bindings/ata/pata-sata-common.yaml

> @@ -0,0 +1,47 @@

> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)

> +%YAML 1.2

> +---

> +$id: http://devicetree.org/schemas/ata/pata-sata-common.yaml#

> +$schema: http://devicetree.org/meta-schemas/core.yaml#

> +

> +title: Common Properties for Parallel and Serial AT attachment controllers

> +

> +maintainers:

> +  - Linus Walleij <linus.walleij@linaro.org>

> +

> +description: |

> +  This document defines device tree properties common to most Parallel

> +  (PATA) and Serial (SATA) AT attachment storage devices. It doesn't

> +  constitue a device tree binding specification by itself but is meant to

> +  be referenced by device tree bindings.

> +

> +  The PATA/SATA controller device tree bindings are responsible for

> +  defining whether each property is required or optional.

> +

> +properties:

> +  $nodename:

> +    pattern: "^[ps]ata-controller(@.*)?$"


   I thought the DT spec has long ago standardized the node name as "ide" and "sata"?

> +    description:

> +      Specifies the host controller node.

> +

> +  "#address-cells":

> +    const: 1

> +

> +  "#size-cells":

> +    const: 0

[...]

MBR, Sergei
Linus Walleij Dec. 31, 2019, 5:56 p.m. | #2
On Tue, Dec 31, 2019 at 6:46 PM Sergei Shtylyov
<sergei.shtylyov@cogentembedded.com> wrote:
> On 12/31/2019 08:24 PM, Linus Walleij wrote:


> > +properties:

> > +  $nodename:

> > +    pattern: "^[ps]ata-controller(@.*)?$"

>

>    I thought the DT spec has long ago standardized the node name as "ide" and "sata"?


I'm not 100% sure (Rob can answer) but I have *half-guessed* that the process
so far has been that when we define a schema for some generic node name
we also invent some new generic node name like this, or else all the old DTS
files people have will generate (lots of) errors.

The DTS files can then opt in to the schema by simply renaming its nodes
in accordance: "ide" -> "pata-controller", "sata" -> "sata-controller"
(I have such a patch for the Gemini that I made this for.)

If I'm wrong I'll switch to to ide@ and sata@.

Rob?

Yours,
Linus Walleij
Rob Herring Dec. 31, 2019, 6:30 p.m. | #3
On Tue, Dec 31, 2019 at 10:56 AM Linus Walleij <linus.walleij@linaro.org> wrote:
>

> On Tue, Dec 31, 2019 at 6:46 PM Sergei Shtylyov

> <sergei.shtylyov@cogentembedded.com> wrote:

> > On 12/31/2019 08:24 PM, Linus Walleij wrote:

>

> > > +properties:

> > > +  $nodename:

> > > +    pattern: "^[ps]ata-controller(@.*)?$"

> >

> >    I thought the DT spec has long ago standardized the node name as "ide" and "sata"?


Correct.

> I'm not 100% sure (Rob can answer) but I have *half-guessed* that the process

> so far has been that when we define a schema for some generic node name

> we also invent some new generic node name like this, or else all the old DTS

> files people have will generate (lots of) errors.


The list of generic node names is a lot longer than what we have
schema for currently.

> The DTS files can then opt in to the schema by simply renaming its nodes

> in accordance: "ide" -> "pata-controller", "sata" -> "sata-controller"

> (I have such a patch for the Gemini that I made this for.)

>

> If I'm wrong I'll switch to to ide@ and sata@.

>

> Rob?

>

> Yours,

> Linus Walleij
Rob Herring Dec. 31, 2019, 6:44 p.m. | #4
On Tue, Dec 31, 2019 at 10:25 AM Linus Walleij <linus.walleij@linaro.org> wrote:
>

> I need to create subnodes for drives connected to PATA

> or SATA host controllers, and this needs to be supported

> generally, so create a common YAML binding for

> "pata-controller" or "sata-controller" that will support

> subnodes with drives.

>

> Cc: Rob Herring <robh+dt@kernel.org>

> Cc: devicetree@vger.kernel.org

> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

> ---

>  .../bindings/ata/pata-sata-common.yaml        | 47 +++++++++++++++++++

>  1 file changed, 47 insertions(+)

>  create mode 100644 Documentation/devicetree/bindings/ata/pata-sata-common.yaml

>

> diff --git a/Documentation/devicetree/bindings/ata/pata-sata-common.yaml b/Documentation/devicetree/bindings/ata/pata-sata-common.yaml

> new file mode 100644

> index 000000000000..d94aa20a29e3

> --- /dev/null

> +++ b/Documentation/devicetree/bindings/ata/pata-sata-common.yaml

> @@ -0,0 +1,47 @@

> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)

> +%YAML 1.2

> +---

> +$id: http://devicetree.org/schemas/ata/pata-sata-common.yaml#

> +$schema: http://devicetree.org/meta-schemas/core.yaml#

> +

> +title: Common Properties for Parallel and Serial AT attachment controllers

> +

> +maintainers:

> +  - Linus Walleij <linus.walleij@linaro.org>

> +

> +description: |

> +  This document defines device tree properties common to most Parallel

> +  (PATA) and Serial (SATA) AT attachment storage devices. It doesn't

> +  constitue a device tree binding specification by itself but is meant to

> +  be referenced by device tree bindings.

> +

> +  The PATA/SATA controller device tree bindings are responsible for

> +  defining whether each property is required or optional.

> +

> +properties:

> +  $nodename:

> +    pattern: "^[ps]ata-controller(@.*)?$"

> +    description:

> +      Specifies the host controller node.

> +

> +  "#address-cells":

> +    const: 1

> +

> +  "#size-cells":

> +    const: 0

> +

> +patternProperties:

> +  "^drive@[0-1]$":

> +    description: |

> +      DT nodes for drives connected on the PATA or SATA host. The master drive

> +      will have ID number 0 and the slave drive will have ID number 1.

> +    type: object


See ata/ahci-platform.txt. We already have child nodes defined as
ports which is essentially a drive (though IIRC SATA can have a mux).
Arguably, we could have both ports and then a drive child under that,
but I've never seen a case of a drive needing DT properties (that
would imply a non-standard connector). So either split this into
separate IDE/PATA and SATA schemas or extend this to work with SATA
ports.

Also, you might consider if you need a regulator property for IDE.

> +

> +    properties:

> +      reg:

> +        minimum: 0

> +        maximum: 1

> +        description:

> +          The ID number of the drive, 0 for the master and 1 for the slave.


Why do you need to describe the drives in DT for IDE? They are
discoverable, right? And unlike SATA, the power to master and slave is
shared.

Rob

Patch

diff --git a/Documentation/devicetree/bindings/ata/pata-sata-common.yaml b/Documentation/devicetree/bindings/ata/pata-sata-common.yaml
new file mode 100644
index 000000000000..d94aa20a29e3
--- /dev/null
+++ b/Documentation/devicetree/bindings/ata/pata-sata-common.yaml
@@ -0,0 +1,47 @@ 
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/ata/pata-sata-common.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Common Properties for Parallel and Serial AT attachment controllers
+
+maintainers:
+  - Linus Walleij <linus.walleij@linaro.org>
+
+description: |
+  This document defines device tree properties common to most Parallel
+  (PATA) and Serial (SATA) AT attachment storage devices. It doesn't
+  constitue a device tree binding specification by itself but is meant to
+  be referenced by device tree bindings.
+
+  The PATA/SATA controller device tree bindings are responsible for
+  defining whether each property is required or optional.
+
+properties:
+  $nodename:
+    pattern: "^[ps]ata-controller(@.*)?$"
+    description:
+      Specifies the host controller node.
+
+  "#address-cells":
+    const: 1
+
+  "#size-cells":
+    const: 0
+
+patternProperties:
+  "^drive@[0-1]$":
+    description: |
+      DT nodes for drives connected on the PATA or SATA host. The master drive
+      will have ID number 0 and the slave drive will have ID number 1.
+    type: object
+
+    properties:
+      reg:
+        minimum: 0
+        maximum: 1
+        description:
+          The ID number of the drive, 0 for the master and 1 for the slave.
+
+...