On Mon, Nov 09, 2020 at 10:15:34PM -0800, Prashant Malani wrote: > Add a user-visible attribute for the number of alternate modes available > in a partner. This allows userspace to determine whether there are any > remaining alternate modes left to be registered by the kernel driver. It > can begin executing any policy state machine after all available > alternate modes have been registered with the connector class framework. > > This value is set to "-1" initially, signifying that a valid number of > alternate modes haven't been set for the partner. > > Also add a sysfs file which exposes this attribute. The file remains > hidden as long as the attribute value is -1. > > Cc: Benson Leung <bleung@xxxxxxxxxxxx> > Cc: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx> > Signed-off-by: Prashant Malani <pmalani@xxxxxxxxxxxx> Reviewed-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx> > --- > > Changes in v2: > - Added ABI/testing documentation entry for added sysfs file. > - Changed name of the sysfs file to "number_of_alternate_modes" based on > review comments. > - Added is_visible() logic suggested by Heikki in the comments of v1. > - Updated commit message. > > v1: > https://lore.kernel.org/lkml/20200701003149.3101219-1-pmalani@xxxxxxxxxxxx/ > > Documentation/ABI/testing/sysfs-class-typec | 8 +++ > drivers/usb/typec/class.c | 66 ++++++++++++++++++++- > include/linux/usb/typec.h | 1 + > 3 files changed, 74 insertions(+), 1 deletion(-) > > diff --git a/Documentation/ABI/testing/sysfs-class-typec b/Documentation/ABI/testing/sysfs-class-typec > index b834671522d6..73ac7b461ae5 100644 > --- a/Documentation/ABI/testing/sysfs-class-typec > +++ b/Documentation/ABI/testing/sysfs-class-typec > @@ -134,6 +134,14 @@ Description: > Shows if the partner supports USB Power Delivery communication: > Valid values: yes, no > > +What: /sys/class/typec/<port>-partner/number_of_alternate_modes > +Date: November 2020 > +Contact: Prashant Malani <pmalani@xxxxxxxxxxxx> > +Description: > + Shows the number of alternate modes which are advertised by the partner > + during Power Delivery discovery. This file remains hidden until a value > + greater than or equal to 0 is set by Type C port driver. > + > What: /sys/class/typec/<port>-partner>/identity/ > Date: April 2017 > Contact: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx> > diff --git a/drivers/usb/typec/class.c b/drivers/usb/typec/class.c > index 35eec707cb51..c7412ddbd311 100644 > --- a/drivers/usb/typec/class.c > +++ b/drivers/usb/typec/class.c > @@ -33,6 +33,7 @@ struct typec_partner { > struct usb_pd_identity *identity; > enum typec_accessory accessory; > struct ida mode_ids; > + int num_altmodes; > }; > > struct typec_port { > @@ -532,12 +533,43 @@ static ssize_t supports_usb_power_delivery_show(struct device *dev, > } > static DEVICE_ATTR_RO(supports_usb_power_delivery); > > +static ssize_t number_of_alternate_modes_show(struct device *dev, struct device_attribute *attr, > + char *buf) > +{ > + struct typec_partner *p = to_typec_partner(dev); > + > + return sysfs_emit(buf, "%d\n", p->num_altmodes); > +} > +static DEVICE_ATTR_RO(number_of_alternate_modes); > + > static struct attribute *typec_partner_attrs[] = { > &dev_attr_accessory_mode.attr, > &dev_attr_supports_usb_power_delivery.attr, > + &dev_attr_number_of_alternate_modes.attr, > + NULL > +}; > + > +static umode_t typec_partner_attr_is_visible(struct kobject *kobj, struct attribute *attr, int n) > +{ > + struct typec_partner *partner = to_typec_partner(kobj_to_dev(kobj)); > + > + if (attr == &dev_attr_number_of_alternate_modes.attr) { > + if (partner->num_altmodes < 0) > + return 0; > + } > + > + return attr->mode; > +} > + > +static struct attribute_group typec_partner_group = { > + .is_visible = typec_partner_attr_is_visible, > + .attrs = typec_partner_attrs > +}; > + > +static const struct attribute_group *typec_partner_groups[] = { > + &typec_partner_group, > NULL > }; > -ATTRIBUTE_GROUPS(typec_partner); > > static void typec_partner_release(struct device *dev) > { > @@ -570,6 +602,37 @@ int typec_partner_set_identity(struct typec_partner *partner) > } > EXPORT_SYMBOL_GPL(typec_partner_set_identity); > > +/** > + * typec_partner_set_num_altmodes - Set the number of available partner altmodes > + * @partner: The partner to be updated. > + * @num_alt_modes: The number of altmodes we want to specify as available. > + * > + * This routine is used to report the number of alternate modes supported by the > + * partner. This value is *not* enforced in alternate mode registration routines. > + * > + * @partner.num_altmodes is set to -1 on partner registration, denoting that > + * a valid value has not been set for it yet. > + * > + * Returns 0 on success or negative error number on failure. > + */ > +int typec_partner_set_num_altmodes(struct typec_partner *partner, int num_altmodes) > +{ > + int ret; > + > + if (num_altmodes < 0) > + return -EINVAL; > + > + partner->num_altmodes = num_altmodes; > + ret = sysfs_update_group(&partner->dev.kobj, &typec_partner_group); > + if (ret < 0) > + return ret; > + > + sysfs_notify(&partner->dev.kobj, NULL, "number_of_alternate_modes"); > + > + return 0; > +} > +EXPORT_SYMBOL_GPL(typec_partner_set_num_altmodes); > + > /** > * typec_partner_register_altmode - Register USB Type-C Partner Alternate Mode > * @partner: USB Type-C Partner that supports the alternate mode > @@ -612,6 +675,7 @@ struct typec_partner *typec_register_partner(struct typec_port *port, > ida_init(&partner->mode_ids); > partner->usb_pd = desc->usb_pd; > partner->accessory = desc->accessory; > + partner->num_altmodes = -1; > > if (desc->identity) { > /* > diff --git a/include/linux/usb/typec.h b/include/linux/usb/typec.h > index 6be558045942..bc6b1a71cb8a 100644 > --- a/include/linux/usb/typec.h > +++ b/include/linux/usb/typec.h > @@ -126,6 +126,7 @@ struct typec_altmode_desc { > enum typec_port_data roles; > }; > > +int typec_partner_set_num_altmodes(struct typec_partner *partner, int num_altmodes); > struct typec_altmode > *typec_partner_register_altmode(struct typec_partner *partner, > const struct typec_altmode_desc *desc); > -- > 2.29.2.222.g5d2a92d10f8-goog thanks, -- heikki
