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[PATCH 2/7] iio: backend: add support for data size set

Antoniu Miclaus posted 7 patches 2 months ago
There is a newer version of this series
[PATCH 2/7] iio: backend: add support for data size set
Posted by Antoniu Miclaus 2 months ago 
Add backend support for setting the data size used.

Signed-off-by: Antoniu Miclaus <antoniu.miclaus@analog.com>
---
 drivers/iio/industrialio-backend.c | 21 +++++++++++++++++++++
 include/linux/iio/backend.h        |  3 +++
 2 files changed, 24 insertions(+)

diff --git a/drivers/iio/industrialio-backend.c b/drivers/iio/industrialio-backend.c
index 53ab6bc86a50..a6a6bedce7f1 100644
--- a/drivers/iio/industrialio-backend.c
+++ b/drivers/iio/industrialio-backend.c
@@ -473,6 +473,27 @@ int iio_backend_interface_type_get(struct iio_backend *back,
 }
 EXPORT_SYMBOL_NS_GPL(iio_backend_interface_type_get, IIO_BACKEND);
 
+/**
+ * iio_backend_data_size_set - set the data width/size in the data bus.
+ * @back: Backend device
+ * @size: Size in bits
+ *
+ * Some frontend devices can dynamically control the word/data size on the
+ * interface/data bus. Hence, the backend device needs to be aware of it so
+ * data can be correctly transferred.
+ *
+ * RETURNS:
+ * 0 on success, negative error number on failure.
+ */
+ssize_t iio_backend_data_size_set(struct iio_backend *back, ssize_t size)
+{
+	if (!size)
+		return -EINVAL;
+
+	return iio_backend_op_call(back, data_size_set, size);
+}
+EXPORT_SYMBOL_NS_GPL(iio_backend_data_size_set, IIO_BACKEND);
+
 /**
  * iio_backend_extend_chan_spec - Extend an IIO channel
  * @indio_dev: IIO device
diff --git a/include/linux/iio/backend.h b/include/linux/iio/backend.h
index ba8ad30ac9ba..85b33ed69cc0 100644
--- a/include/linux/iio/backend.h
+++ b/include/linux/iio/backend.h
@@ -87,6 +87,7 @@ enum iio_backend_interface_type {
  * @ext_info_set: Extended info setter.
  * @ext_info_get: Extended info getter.
  * @interface_type_get: Interface type.
+ * @data_size_set: Data size.
  **/
 struct iio_backend_ops {
 	int (*enable)(struct iio_backend *back);
@@ -121,6 +122,7 @@ struct iio_backend_ops {
 			    const struct iio_chan_spec *chan, char *buf);
 	int (*interface_type_get)(struct iio_backend *back,
 				  enum iio_backend_interface_type *type);
+	int (*data_size_set)(struct iio_backend *back, ssize_t size);
 };
 
 int iio_backend_chan_enable(struct iio_backend *back, unsigned int chan);
@@ -152,6 +154,7 @@ ssize_t iio_backend_ext_info_get(struct iio_dev *indio_dev, uintptr_t private,
 
 int iio_backend_interface_type_get(struct iio_backend *back,
 				   enum iio_backend_interface_type *type);
+ssize_t iio_backend_data_size_set(struct iio_backend *back, ssize_t size);
 int iio_backend_extend_chan_spec(struct iio_dev *indio_dev,
 				 struct iio_backend *back,
 				 struct iio_chan_spec *chan);
-- 
2.46.0
Re: [PATCH 2/7] iio: backend: add support for data size set
Posted by Jonathan Cameron 2 months ago 
On Mon, 23 Sep 2024 13:10:19 +0300
Antoniu Miclaus <antoniu.miclaus@analog.com> wrote:

> Add backend support for setting the data size used.

Say 'why' a device might do this.  I assume in general
it's because you haven't wired all the pins, but is there a
reason it might be dynamic?

Jonathan

> 
> Signed-off-by: Antoniu Miclaus <antoniu.miclaus@analog.com>
> ---
>  drivers/iio/industrialio-backend.c | 21 +++++++++++++++++++++
>  include/linux/iio/backend.h        |  3 +++
>  2 files changed, 24 insertions(+)
> 
> diff --git a/drivers/iio/industrialio-backend.c b/drivers/iio/industrialio-backend.c
> index 53ab6bc86a50..a6a6bedce7f1 100644
> --- a/drivers/iio/industrialio-backend.c
> +++ b/drivers/iio/industrialio-backend.c
> @@ -473,6 +473,27 @@ int iio_backend_interface_type_get(struct iio_backend *back,
>  }
>  EXPORT_SYMBOL_NS_GPL(iio_backend_interface_type_get, IIO_BACKEND);
>  
> +/**
> + * iio_backend_data_size_set - set the data width/size in the data bus.
> + * @back: Backend device
> + * @size: Size in bits
> + *
> + * Some frontend devices can dynamically control the word/data size on the
> + * interface/data bus. Hence, the backend device needs to be aware of it so
> + * data can be correctly transferred.
> + *
> + * RETURNS:
> + * 0 on success, negative error number on failure.
> + */
> +ssize_t iio_backend_data_size_set(struct iio_backend *back, ssize_t size)
> +{
> +	if (!size)
> +		return -EINVAL;
> +
> +	return iio_backend_op_call(back, data_size_set, size);
> +}
> +EXPORT_SYMBOL_NS_GPL(iio_backend_data_size_set, IIO_BACKEND);
> +
>  /**
>   * iio_backend_extend_chan_spec - Extend an IIO channel
>   * @indio_dev: IIO device
> diff --git a/include/linux/iio/backend.h b/include/linux/iio/backend.h
> index ba8ad30ac9ba..85b33ed69cc0 100644
> --- a/include/linux/iio/backend.h
> +++ b/include/linux/iio/backend.h
> @@ -87,6 +87,7 @@ enum iio_backend_interface_type {
>   * @ext_info_set: Extended info setter.
>   * @ext_info_get: Extended info getter.
>   * @interface_type_get: Interface type.
> + * @data_size_set: Data size.
>   **/
>  struct iio_backend_ops {
>  	int (*enable)(struct iio_backend *back);
> @@ -121,6 +122,7 @@ struct iio_backend_ops {
>  			    const struct iio_chan_spec *chan, char *buf);
>  	int (*interface_type_get)(struct iio_backend *back,
>  				  enum iio_backend_interface_type *type);
> +	int (*data_size_set)(struct iio_backend *back, ssize_t size);
>  };
>  
>  int iio_backend_chan_enable(struct iio_backend *back, unsigned int chan);
> @@ -152,6 +154,7 @@ ssize_t iio_backend_ext_info_get(struct iio_dev *indio_dev, uintptr_t private,
>  
>  int iio_backend_interface_type_get(struct iio_backend *back,
>  				   enum iio_backend_interface_type *type);
> +ssize_t iio_backend_data_size_set(struct iio_backend *back, ssize_t size);
>  int iio_backend_extend_chan_spec(struct iio_dev *indio_dev,
>  				 struct iio_backend *back,
>  				 struct iio_chan_spec *chan);
Re: [PATCH 2/7] iio: backend: add support for data size set
Posted by David Lechner 2 months ago 
On Mon, Sep 23, 2024 at 12:16 PM Antoniu Miclaus
<antoniu.miclaus@analog.com> wrote:
>
> Add backend support for setting the data size used.
>
> Signed-off-by: Antoniu Miclaus <antoniu.miclaus@analog.com>
> ---
>  drivers/iio/industrialio-backend.c | 21 +++++++++++++++++++++
>  include/linux/iio/backend.h        |  3 +++
>  2 files changed, 24 insertions(+)
>
> diff --git a/drivers/iio/industrialio-backend.c b/drivers/iio/industrialio-backend.c
> index 53ab6bc86a50..a6a6bedce7f1 100644
> --- a/drivers/iio/industrialio-backend.c
> +++ b/drivers/iio/industrialio-backend.c
> @@ -473,6 +473,27 @@ int iio_backend_interface_type_get(struct iio_backend *back,
>  }
>  EXPORT_SYMBOL_NS_GPL(iio_backend_interface_type_get, IIO_BACKEND);
>
> +/**
> + * iio_backend_data_size_set - set the data width/size in the data bus.
> + * @back: Backend device
> + * @size: Size in bits
> + *
> + * Some frontend devices can dynamically control the word/data size on the
> + * interface/data bus. Hence, the backend device needs to be aware of it so
> + * data can be correctly transferred.
> + *
> + * RETURNS:
> + * 0 on success, negative error number on failure.
> + */
> +ssize_t iio_backend_data_size_set(struct iio_backend *back, ssize_t size)

Why signed size? When will it be < 0?

> +{
> +       if (!size)
> +               return -EINVAL;
> +
> +       return iio_backend_op_call(back, data_size_set, size);
> +}
> +EXPORT_SYMBOL_NS_GPL(iio_backend_data_size_set, IIO_BACKEND);
> +
Re: [PATCH 2/7] iio: backend: add support for data size set
Posted by Andy Shevchenko 2 months ago 
On Mon, Sep 23, 2024 at 01:10:19PM +0300, Antoniu Miclaus wrote:
> Add backend support for setting the data size used.

...

> + * RETURNS:

It's main in this file, please add a patch that converts all 'RETURN' and
'RETURNS' to 'Return:'. Or at bare minimum use "Return:" here.

> + */

...

> +	if (!size)
> +		return -EINVAL;

Why 0 can be set? Is it default?

-- 
With Best Regards,
Andy Shevchenko

Patchew 2.1-devel-b67e4c2

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