[PATCH 0/2] docs: driver-model: device: Add helper macro examples

[PATCH 0/2] docs: driver-model: device: Add helper macro examples

[Geert Uytterhoeven]

	Hi Jon, Greg, Rafael,

The DEVICE_ATTR_* and ATTRIBUTE_GROUPS() helper macros have existed for
more than a decade, but are still not mentioned in the driver-model
device documentation.  Hence this patch series adds them, including
examples, to the documentation.

Thanks for your comments!

Geert Uytterhoeven (2):
  docs: driver-model: device: Add DEVICE_ATTR_{RO,RW} examples
  docs: driver-model: device: Add ATTRIBUTE_GROUPS() example

 .../driver-api/driver-model/device.rst        | 23 ++++++++++++++-----
 1 file changed, 17 insertions(+), 6 deletions(-)

-- 
2.25.1

Gr{oetje,eeting}s,

						Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
							    -- Linus Torvalds

[PATCH 1/2] docs: driver-model: device: Add DEVICE_ATTR_{RO,RW} examples

[Geert Uytterhoeven]

bus.rst, driver.rst, and hwmon-kernel-api.rst refer to the
DEVICE_ATTR_* macros for devices, but device.rst does not mention them.

Add a paragraph about these helper macros, and use them in the examples.
Retain the old description, as it is still useful for less common values
of mode.  Change the names of the example "show" and "store" methods, to
match the expectations of the DEVICE_ATTR_* macros.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
 Documentation/driver-api/driver-model/device.rst | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/Documentation/driver-api/driver-model/device.rst b/Documentation/driver-api/driver-model/device.rst
index b9b022371e856e83..41c819fafd9c1aee 100644
--- a/Documentation/driver-api/driver-model/device.rst
+++ b/Documentation/driver-api/driver-model/device.rst
@@ -63,8 +63,14 @@ Attributes are declared using a macro called DEVICE_ATTR::
 
 Example:::
 
-  static DEVICE_ATTR(type, 0444, show_type, NULL);
-  static DEVICE_ATTR(power, 0644, show_power, store_power);
+  static DEVICE_ATTR(type, 0444, type_show, NULL);
+  static DEVICE_ATTR(power, 0644, power_show, power_store);
+
+Helper macros are available for common values of mode, so the above examples
+can be simplified to:::
+
+  static DEVICE_ATTR_RO(type);
+  static DEVICE_ATTR_RW(power);
 
 This declares two structures of type struct device_attribute with respective
 names 'dev_attr_type' and 'dev_attr_power'. These two attributes can be
-- 
2.25.1

[PATCH 2/2] docs: driver-model: device: Add ATTRIBUTE_GROUPS() example

[Geert Uytterhoeven]

Add a paragraph about the ATTRIBUTE_GROUPS() helper macro, and use it in
the example.  Retain the old description, as it is still useful in case
of multiple groups.  Change the names of the group(s) structures, to
match the ATTRIBUTE_GROUPS() macro.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
 Documentation/driver-api/driver-model/device.rst | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/Documentation/driver-api/driver-model/device.rst b/Documentation/driver-api/driver-model/device.rst
index 41c819fafd9c1aee..0833be568b06cace 100644
--- a/Documentation/driver-api/driver-model/device.rst
+++ b/Documentation/driver-api/driver-model/device.rst
@@ -82,19 +82,24 @@ organized as follows into a group::
 	NULL,
   };
 
-  static struct attribute_group dev_attr_group = {
+  static struct attribute_group dev_group = {
 	.attrs = dev_attrs,
   };
 
-  static const struct attribute_group *dev_attr_groups[] = {
-	&dev_attr_group,
+  static const struct attribute_group *dev_groups[] = {
+	&dev_group,
 	NULL,
   };
 
+A helper macro is available for the common case of a single group, so the
+above two structures can be declared using:::
+
+  ATTRIBUTE_GROUPS(dev);
+
 This array of groups can then be associated with a device by setting the
 group pointer in struct device before device_register() is invoked::
 
-        dev->groups = dev_attr_groups;
+        dev->groups = dev_groups;
         device_register(dev);
 
 The device_register() function will use the 'groups' pointer to create the
-- 
2.25.1

Re: [PATCH 0/2] docs: driver-model: device: Add helper macro examples

[Greg Kroah-Hartman]

On Wed, Mar 03, 2021 at 02:38:43PM +0100, Geert Uytterhoeven wrote:
> 	Hi Jon, Greg, Rafael,
> 
> The DEVICE_ATTR_* and ATTRIBUTE_GROUPS() helper macros have existed for
> more than a decade, but are still not mentioned in the driver-model
> device documentation.  Hence this patch series adds them, including
> examples, to the documentation.
> 
> Thanks for your comments!
> 
> Geert Uytterhoeven (2):
>   docs: driver-model: device: Add DEVICE_ATTR_{RO,RW} examples
>   docs: driver-model: device: Add ATTRIBUTE_GROUPS() example

Thanks for adding these:

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Re: [PATCH 0/2] docs: driver-model: device: Add helper macro examples

[Jonathan Corbet]

Geert Uytterhoeven <geert+renesas@glider.be> writes:

> 	Hi Jon, Greg, Rafael,
>
> The DEVICE_ATTR_* and ATTRIBUTE_GROUPS() helper macros have existed for
> more than a decade, but are still not mentioned in the driver-model
> device documentation.  Hence this patch series adds them, including
> examples, to the documentation.
>
> Thanks for your comments!
>
> Geert Uytterhoeven (2):
>   docs: driver-model: device: Add DEVICE_ATTR_{RO,RW} examples
>   docs: driver-model: device: Add ATTRIBUTE_GROUPS() example
>
>  .../driver-api/driver-model/device.rst        | 23 ++++++++++++++-----
>  1 file changed, 17 insertions(+), 6 deletions(-)

Set applied, thanks.

jon