Re: [PATCH] usb: pd: Exposing the Peak Current value of Fixed Supplies to user space

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Wed, Sep 27, 2023 at 02:10:31PM +0300, Heikki Krogerus wrote:
> Exposing the value of the field as is.
> 
> The Peak Current value has to be interpreted as described
> in Table 6-10 (Fixed Power Source Peak Current Capability)
> of the USB Power Delivery Specification, but that
> interpretation will be done in user space, not in kernel.
> 
> Suggested-by: Douglas Gilbert <dgilbert@interlog.com>
> Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> ---
>  drivers/usb/typec/pd.c | 10 ++++------
>  include/linux/usb/pd.h |  1 +
>  2 files changed, 5 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/usb/typec/pd.c b/drivers/usb/typec/pd.c
> index 8cc66e4467c4..85d015cdbe1f 100644
> --- a/drivers/usb/typec/pd.c
> +++ b/drivers/usb/typec/pd.c
> @@ -83,14 +83,12 @@ unchunked_extended_messages_supported_show(struct device *dev,
>  }
>  static DEVICE_ATTR_RO(unchunked_extended_messages_supported);
>  
> -/*
> - * REVISIT: Peak Current requires access also to the RDO.
>  static ssize_t
>  peak_current_show(struct device *dev, struct device_attribute *attr, char *buf)
>  {
> -	...
> +	return sysfs_emit(buf, "%u\n", (to_pdo(dev)->pdo >> PDO_FIXED_PEAK_CURR_SHIFT) & 3);
>  }
> -*/
> +static DEVICE_ATTR_RO(peak_current);

Don't you need to add a Documentation/ABI/ entry for this new field?

thanks,

greg k-h