Re: [PATCH v3 2/2] usb: typec: pd: Add higher capability sysfs for sink PDO

[Heikki Krogerus <heikki.krogerus@linux.intel.com>]

On Tue, Feb 14, 2023 at 05:15:43PM +0530, Saranya Gopal wrote:
> 28th bit of fixed supply sink PDO represents higher capability.
> When this bit is set, the sink device needs more than vsafe5V
> (eg: 12 V) to provide full functionality. This patch adds
> this higher capability sysfs interface for sink PDO.
> 28th bit of fixed supply source PDO represents usb_suspend_supported
> attribute. This usb_suspend_supported sysfs is already exposed for
> source PDOs. This patch adds 'source-capabilities' in
> usb_suspend_supported sysfs documentation for additional clarity.
> 
> Signed-off-by: Saranya Gopal <saranya.gopal@intel.com>

Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>

> ---
> Changes from v2:
>  - Patch was split into 2 and this one adds new sysfs for sink PDO
> Changes from v1:
>  - Wrapped the description within 80 characters
>  - Added valid values for the new sysfs
> 
>  .../ABI/testing/sysfs-class-usb_power_delivery        | 11 ++++++++++-
>  drivers/usb/typec/pd.c                                |  8 ++++++++
>  2 files changed, 18 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/ABI/testing/sysfs-class-usb_power_delivery b/Documentation/ABI/testing/sysfs-class-usb_power_delivery
> index ce2b1b563cb3..1bf9d1d7902c 100644
> --- a/Documentation/ABI/testing/sysfs-class-usb_power_delivery
> +++ b/Documentation/ABI/testing/sysfs-class-usb_power_delivery
> @@ -69,7 +69,7 @@ Description:
>  		This file contains boolean value that tells does the device
>  		support both source and sink power roles.
>  
> -What:		/sys/class/usb_power_delivery/.../<capability>/1:fixed_supply/usb_suspend_supported
> +What:		/sys/class/usb_power_delivery/.../source-capabilities/1:fixed_supply/usb_suspend_supported
>  Date:		May 2022
>  Contact:	Heikki Krogerus <heikki.krogerus@linux.intel.com>
>  Description:
> @@ -78,6 +78,15 @@ Description:
>  		will follow the USB 2.0 and USB 3.2 rules for suspend and
>  		resume.
>  
> +What:		/sys/class/usb_power_delivery/.../sink-capabilities/1:fixed_supply/higher_capability
> +Date:		February 2023
> +Contact:	Saranya Gopal <saranya.gopal@linux.intel.com>
> +Description:
> +		This file shows the value of the Higher capability bit in
> +		vsafe5V Fixed Supply Object. If the bit is set, then the sink
> +		needs more than vsafe5V(eg. 12 V) to provide full functionality.
> +		Valid values: 0, 1
> +
>  What:		/sys/class/usb_power_delivery/.../<capability>/1:fixed_supply/unconstrained_power
>  Date:		May 2022
>  Contact:	Heikki Krogerus <heikki.krogerus@linux.intel.com>
> diff --git a/drivers/usb/typec/pd.c b/drivers/usb/typec/pd.c
> index b5ab26422c34..59c537a5e600 100644
> --- a/drivers/usb/typec/pd.c
> +++ b/drivers/usb/typec/pd.c
> @@ -48,6 +48,13 @@ usb_suspend_supported_show(struct device *dev, struct device_attribute *attr, ch
>  }
>  static DEVICE_ATTR_RO(usb_suspend_supported);
>  
> +static ssize_t
> +higher_capability_show(struct device *dev, struct device_attribute *attr, char *buf)
> +{
> +	return sysfs_emit(buf, "%u\n", !!(to_pdo(dev)->pdo & PDO_FIXED_HIGHER_CAP));
> +}
> +static DEVICE_ATTR_RO(higher_capability);
> +
>  static ssize_t
>  unconstrained_power_show(struct device *dev, struct device_attribute *attr, char *buf)
>  {
> @@ -161,6 +168,7 @@ static struct device_type source_fixed_supply_type = {
>  
>  static struct attribute *sink_fixed_supply_attrs[] = {
>  	&dev_attr_dual_role_power.attr,
> +	&dev_attr_higher_capability.attr,
>  	&dev_attr_unconstrained_power.attr,
>  	&dev_attr_usb_communication_capable.attr,
>  	&dev_attr_dual_role_data.attr,
> -- 
> 2.25.1

-- 
heikki