Re: [PATCH v3] iio: Use octal permissions and DEVICE_ATTR_{RO,RW}.

From: Andy Shevchenko
Date: Wed Jun 01 2022 - 17:13:29 EST


On Wed, Jun 1, 2022 at 8:54 PM Joe Simmons-Talbott <joetalbott@xxxxxxxxx> wrote:
>
> As reported by checkpatch.pl. Where possible use DEVICE_ATTR_RO(),
> DEVICE_ATTR_RW(), and __ATTR_RO(). Change function names to be
> <var>_show() for read and <var>_store() for write.

Thank you for an update!
I have a few nit-picks, but no need to resend, I believe Jonathan may
(or may not :) modify when applying.
Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>

> Suggested-by: Joe Perches <joe@xxxxxxxxxxx>
> Suggested-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
> Signed-off-by: Joe Simmons-Talbott <joetalbott@xxxxxxxxx>
> ---
>
> Changes in v3:
> - Use __ATTR_RO() and add parens to DEVICE_ATTR_{RW,RO} in description
> as suggested by Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
>
> Changes in v2:
> - Use DEVICE_ATTR_RO() and DEVICE_ATTR_RW() rather than octal permissions
> where applicable. Rename functions to <var>-show() and
> <var>-store(). Based on review by Joe Perches <joe@xxxxxxxxxxx>
>
> drivers/iio/industrialio-buffer.c | 64 ++++++++++++++----------------
> drivers/iio/industrialio-core.c | 35 ++++++++--------
> drivers/iio/industrialio-trigger.c | 32 +++++++--------
> 3 files changed, 61 insertions(+), 70 deletions(-)
>
> diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c
> index b078eb2f3c9d..80121b1ac554 100644
> --- a/drivers/iio/industrialio-buffer.c
> +++ b/drivers/iio/industrialio-buffer.c
> @@ -630,18 +630,18 @@ static int iio_buffer_add_channel_sysfs(struct iio_dev *indio_dev,
> return ret;
> }
>
> -static ssize_t iio_buffer_read_length(struct device *dev,
> - struct device_attribute *attr,
> - char *buf)
> +static ssize_t length_show(struct device *dev,
> + struct device_attribute *attr,

I think we have enough space to move the attr parameter to the previous line.

> + char *buf)
> {
> struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer;
>
> return sysfs_emit(buf, "%d\n", buffer->length);
> }
>
> -static ssize_t iio_buffer_write_length(struct device *dev,
> - struct device_attribute *attr,
> - const char *buf, size_t len)
> +static ssize_t length_store(struct device *dev,
> + struct device_attribute *attr,

Ditto.

> + const char *buf, size_t len)
> {
> struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer;
> @@ -672,9 +672,9 @@ static ssize_t iio_buffer_write_length(struct device *dev,
> return ret ? ret : len;
> }
>
> -static ssize_t iio_buffer_show_enable(struct device *dev,
> - struct device_attribute *attr,
> - char *buf)
> +static ssize_t enable_show(struct device *dev,
> + struct device_attribute *attr,

Ditto.

> + char *buf)
> {
> struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer;
>
> @@ -1289,10 +1289,10 @@ void iio_disable_all_buffers(struct iio_dev *indio_dev)
> iio_buffer_deactivate_all(indio_dev);
> }
>
> -static ssize_t iio_buffer_store_enable(struct device *dev,
> - struct device_attribute *attr,
> - const char *buf,
> - size_t len)
> +static ssize_t enable_store(struct device *dev,
> + struct device_attribute *attr,

Ditto.

> + const char *buf,
> + size_t len)

And these two may be on one line.

> {
> int ret;
> bool requested_state;
> @@ -1322,19 +1322,19 @@ static ssize_t iio_buffer_store_enable(struct device *dev,
> return (ret < 0) ? ret : len;
> }
>
> -static ssize_t iio_buffer_show_watermark(struct device *dev,
> - struct device_attribute *attr,
> - char *buf)
> +static ssize_t watermark_show(struct device *dev,
> + struct device_attribute *attr,

Ditto.

> + char *buf)
> {
> struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer;
>
> return sysfs_emit(buf, "%u\n", buffer->watermark);
> }
>
> -static ssize_t iio_buffer_store_watermark(struct device *dev,
> - struct device_attribute *attr,
> - const char *buf,
> - size_t len)
> +static ssize_t watermark_store(struct device *dev,
> + struct device_attribute *attr,

Ditto.

> + const char *buf,
> + size_t len)

Ditto.

> {
> struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer;
> @@ -1366,9 +1366,9 @@ static ssize_t iio_buffer_store_watermark(struct device *dev,
> return ret ? ret : len;
> }
>
> -static ssize_t iio_dma_show_data_available(struct device *dev,
> - struct device_attribute *attr,
> - char *buf)
> +static ssize_t data_available_show(struct device *dev,
> + struct device_attribute *attr,

Ditto.

> + char *buf)
> {
> struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer;
>
> @@ -1391,18 +1391,12 @@ static ssize_t direction_show(struct device *dev,
> }
> }
>
> -static DEVICE_ATTR(length, S_IRUGO | S_IWUSR, iio_buffer_read_length,
> - iio_buffer_write_length);
> -static struct device_attribute dev_attr_length_ro = __ATTR(length,
> - S_IRUGO, iio_buffer_read_length, NULL);
> -static DEVICE_ATTR(enable, S_IRUGO | S_IWUSR,
> - iio_buffer_show_enable, iio_buffer_store_enable);
> -static DEVICE_ATTR(watermark, S_IRUGO | S_IWUSR,
> - iio_buffer_show_watermark, iio_buffer_store_watermark);
> -static struct device_attribute dev_attr_watermark_ro = __ATTR(watermark,
> - S_IRUGO, iio_buffer_show_watermark, NULL);
> -static DEVICE_ATTR(data_available, S_IRUGO,
> - iio_dma_show_data_available, NULL);
> +static DEVICE_ATTR_RW(length);
> +static struct device_attribute dev_attr_length_ro = __ATTR_RO(length);
> +static DEVICE_ATTR_RW(enable);
> +static DEVICE_ATTR_RW(watermark);
> +static struct device_attribute dev_attr_watermark_ro = __ATTR_RO(watermark);
> +static DEVICE_ATTR_RO(data_available);
> static DEVICE_ATTR_RO(direction);
>
> /*
> diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
> index e1ed44dec2ab..bb1dd00b99ac 100644
> --- a/drivers/iio/industrialio-core.c
> +++ b/drivers/iio/industrialio-core.c
> @@ -1114,12 +1114,12 @@ int __iio_device_attr_init(struct device_attribute *dev_attr,
> dev_attr->attr.name = name;
>
> if (readfunc) {
> - dev_attr->attr.mode |= S_IRUGO;
> + dev_attr->attr.mode |= 0444;
> dev_attr->show = readfunc;
> }
>
> if (writefunc) {
> - dev_attr->attr.mode |= S_IWUSR;
> + dev_attr->attr.mode |= 0200;
> dev_attr->store = writefunc;
> }
>
> @@ -1393,29 +1393,29 @@ void iio_free_chan_devattr_list(struct list_head *attr_list)
> }
> }
>
> -static ssize_t iio_show_dev_name(struct device *dev,
> - struct device_attribute *attr,
> - char *buf)
> +static ssize_t name_show(struct device *dev,
> + struct device_attribute *attr,

Ditto.

> + char *buf)
> {
> struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> return sysfs_emit(buf, "%s\n", indio_dev->name);
> }
>
> -static DEVICE_ATTR(name, S_IRUGO, iio_show_dev_name, NULL);
> +static DEVICE_ATTR_RO(name);
>
> -static ssize_t iio_show_dev_label(struct device *dev,
> - struct device_attribute *attr,
> - char *buf)
> +static ssize_t label_show(struct device *dev,
> + struct device_attribute *attr,

Ditto.

> + char *buf)
> {
> struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> return sysfs_emit(buf, "%s\n", indio_dev->label);
> }
>
> -static DEVICE_ATTR(label, S_IRUGO, iio_show_dev_label, NULL);
> +static DEVICE_ATTR_RO(label);
>
> -static ssize_t iio_show_timestamp_clock(struct device *dev,
> - struct device_attribute *attr,
> - char *buf)
> +static ssize_t current_timestamp_clock_show(struct device *dev,
> + struct device_attribute *attr,
> + char *buf)
> {
> const struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> const clockid_t clk = iio_device_get_clock(indio_dev);
> @@ -1459,9 +1459,9 @@ static ssize_t iio_show_timestamp_clock(struct device *dev,
> return sz;
> }
>
> -static ssize_t iio_store_timestamp_clock(struct device *dev,
> - struct device_attribute *attr,
> - const char *buf, size_t len)
> +static ssize_t current_timestamp_clock_store(struct device *dev,
> + struct device_attribute *attr,
> + const char *buf, size_t len)
> {
> clockid_t clk;
> int ret;
> @@ -1509,8 +1509,7 @@ int iio_device_register_sysfs_group(struct iio_dev *indio_dev,
> return 0;
> }
>
> -static DEVICE_ATTR(current_timestamp_clock, S_IRUGO | S_IWUSR,
> - iio_show_timestamp_clock, iio_store_timestamp_clock);
> +static DEVICE_ATTR_RW(current_timestamp_clock);
>
> static int iio_device_register_sysfs(struct iio_dev *indio_dev)
> {
> diff --git a/drivers/iio/industrialio-trigger.c b/drivers/iio/industrialio-trigger.c
> index f504ed351b3e..21f113c0ee96 100644
> --- a/drivers/iio/industrialio-trigger.c
> +++ b/drivers/iio/industrialio-trigger.c
> @@ -37,7 +37,7 @@ static LIST_HEAD(iio_trigger_list);
> static DEFINE_MUTEX(iio_trigger_list_lock);
>
> /**
> - * iio_trigger_read_name() - retrieve useful identifying name
> + * name_show() - retrieve useful identifying name
> * @dev: device associated with the iio_trigger
> * @attr: pointer to the device_attribute structure that is
> * being processed
> @@ -46,15 +46,15 @@ static DEFINE_MUTEX(iio_trigger_list_lock);
> * Return: a negative number on failure or the number of written
> * characters on success.
> */
> -static ssize_t iio_trigger_read_name(struct device *dev,
> - struct device_attribute *attr,
> - char *buf)
> +static ssize_t name_show(struct device *dev,
> + struct device_attribute *attr,

Ditto.

> + char *buf)
> {
> struct iio_trigger *trig = to_iio_trigger(dev);
> return sysfs_emit(buf, "%s\n", trig->name);
> }
>
> -static DEVICE_ATTR(name, S_IRUGO, iio_trigger_read_name, NULL);
> +static DEVICE_ATTR_RO(name);
>
> static struct attribute *iio_trig_dev_attrs[] = {
> &dev_attr_name.attr,
> @@ -395,7 +395,7 @@ void iio_dealloc_pollfunc(struct iio_poll_func *pf)
> EXPORT_SYMBOL_GPL(iio_dealloc_pollfunc);
>
> /**
> - * iio_trigger_read_current() - trigger consumer sysfs query current trigger
> + * current_trigger_show() - trigger consumer sysfs query current trigger
> * @dev: device associated with an industrial I/O device
> * @attr: pointer to the device_attribute structure that
> * is being processed
> @@ -407,9 +407,9 @@ EXPORT_SYMBOL_GPL(iio_dealloc_pollfunc);
> * Return: a negative number on failure, the number of characters written
> * on success or 0 if no trigger is available
> */
> -static ssize_t iio_trigger_read_current(struct device *dev,
> - struct device_attribute *attr,
> - char *buf)
> +static ssize_t current_trigger_show(struct device *dev,
> + struct device_attribute *attr,

Ditto.

> + char *buf)
> {
> struct iio_dev *indio_dev = dev_to_iio_dev(dev);
>
> @@ -419,7 +419,7 @@ static ssize_t iio_trigger_read_current(struct device *dev,
> }
>
> /**
> - * iio_trigger_write_current() - trigger consumer sysfs set current trigger
> + * current_trigger_store() - trigger consumer sysfs set current trigger
> * @dev: device associated with an industrial I/O device
> * @attr: device attribute that is being processed
> * @buf: string buffer that holds the name of the trigger
> @@ -432,10 +432,10 @@ static ssize_t iio_trigger_read_current(struct device *dev,
> * Return: negative error code on failure or length of the buffer
> * on success
> */
> -static ssize_t iio_trigger_write_current(struct device *dev,
> - struct device_attribute *attr,
> - const char *buf,
> - size_t len)
> +static ssize_t current_trigger_store(struct device *dev,
> + struct device_attribute *attr,

Ditto.

> + const char *buf,
> + size_t len)

Ditto.

> {
> struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
> @@ -494,9 +494,7 @@ static ssize_t iio_trigger_write_current(struct device *dev,
> return ret;
> }
>
> -static DEVICE_ATTR(current_trigger, S_IRUGO | S_IWUSR,
> - iio_trigger_read_current,
> - iio_trigger_write_current);
> +static DEVICE_ATTR_RW(current_trigger);
>
> static struct attribute *iio_trigger_consumer_attrs[] = {
> &dev_attr_current_trigger.attr,
> --
> 2.35.3
>


--
With Best Regards,
Andy Shevchenko