| Message ID | 20230223132452.37958-3-hadess@hadess.net (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/5] HID: logitech-hidpp: Add support for ADC measurement feature | expand |
On Thu, Feb 23, 2023 at 02:24:50PM +0100, Bastien Nocera wrote: > Add a wireless_status sysfs attribute to USB devices to keep track of > whether a USB device that uses a receiver/emitter combo has its > emitter connected or disconnected. That's going to be very vague, and is starting to get very interface-specific as an attibute here. Why can't it just be an input device attribute? Why is "wireless" suddenly a special case for USB devices (we thought we got rid of the old wireless usb code...) > By default, the USB device will declare not to use a receiver/emitter. I do not understand this statement, what do you mean by this? > Signed-off-by: Bastien Nocera <hadess@hadess.net> > --- > Documentation/ABI/testing/sysfs-bus-usb | 12 ++++++ > drivers/usb/core/sysfs.c | 50 +++++++++++++++++++++++++ > drivers/usb/core/usb.h | 1 + > include/linux/usb.h | 10 +++++ > 4 files changed, 73 insertions(+) > > diff --git a/Documentation/ABI/testing/sysfs-bus-usb b/Documentation/ABI/testing/sysfs-bus-usb > index 545c2dd97ed0..0bd22ece05cd 100644 > --- a/Documentation/ABI/testing/sysfs-bus-usb > +++ b/Documentation/ABI/testing/sysfs-bus-usb > @@ -166,6 +166,18 @@ Description: > The file will be present for all speeds of USB devices, and will > always read "no" for USB 1.1 and USB 2.0 devices. > > +What: /sys/bus/usb/devices/<INTERFACE>/wireless_status > +Date: January 2023 January was last month :( > +Contact: Bastien Nocera <hadess@hadess.net> > +Description: > + Some USB devices use a small USB receiver coupled with a larger > + wireless device, usually communicating using proprietary > + wireless protocols. This attribute will read either "connected" > + or "disconnected" depending on whether the emitter is turned on, > + in range and connected, on the interface which is used to detect > + this state. If the device does not use a receiver/emitter combo, > + then this attribute will not exist. So would you declare a wireless network device such a thing? See, it gets tricky, I do not think this should be a generic USB attribute at all. > + > What: /sys/bus/usb/devices/.../<hub_interface>/port<X> > Date: August 2012 > Contact: Lan Tianyu <tianyu.lan@intel.com> > diff --git a/drivers/usb/core/sysfs.c b/drivers/usb/core/sysfs.c > index 8217032dfb85..da3c0f0dd633 100644 > --- a/drivers/usb/core/sysfs.c > +++ b/drivers/usb/core/sysfs.c > @@ -1232,9 +1232,59 @@ static const struct attribute_group intf_assoc_attr_grp = { > .is_visible = intf_assoc_attrs_are_visible, > }; > > +static ssize_t wireless_status_show(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + struct usb_interface *intf; > + > + intf = to_usb_interface(dev); > + if (intf->wireless_status == USB_WIRELESS_STATUS_DISCONNECTED) > + return sysfs_emit(buf, "%s\n", "disconnected"); > + return sysfs_emit(buf, "%s\n", "connected"); > +} > +static DEVICE_ATTR_RO(wireless_status); > + > +static struct attribute *intf_wireless_status_attrs[] = { > + &dev_attr_wireless_status.attr, > + NULL > +}; > + > +static umode_t intf_wireless_status_attr_is_visible(struct kobject *kobj, > + struct attribute *a, int n) > +{ > + struct device *dev = kobj_to_dev(kobj); > + struct usb_interface *intf = to_usb_interface(dev); > + > + if (a != &dev_attr_wireless_status.attr || > + intf->wireless_status != USB_WIRELESS_STATUS_NA) > + return a->mode; > + return 0; > +} > + > +static const struct attribute_group intf_wireless_status_attr_grp = { > + .attrs = intf_wireless_status_attrs, > + .is_visible = intf_wireless_status_attr_is_visible, > +}; > + > +int usb_update_wireless_status_attr(struct usb_interface *intf) > +{ > + struct device *dev = &intf->dev; > + int ret; > + > + ret = sysfs_update_group(&dev->kobj, &intf_wireless_status_attr_grp); > + if (ret < 0) > + return ret; > + > + sysfs_notify(&dev->kobj, NULL, "wireless_status"); > + kobject_uevent(&dev->kobj, KOBJ_CHANGE); That could be very noisy, why does that deserve a KOBJ_CHANGE event? thanks, greg k-h
On Thu, 2023-02-23 at 14:51 +0100, Greg Kroah-Hartman wrote: > On Thu, Feb 23, 2023 at 02:24:50PM +0100, Bastien Nocera wrote: > > Add a wireless_status sysfs attribute to USB devices to keep track > > of > > whether a USB device that uses a receiver/emitter combo has its > > emitter connected or disconnected. > > That's going to be very vague, and is starting to get very > interface-specific as an attibute here. > > Why can't it just be an input device attribute? Why is "wireless" > suddenly a special case for USB devices (we thought we got rid of the > old wireless usb code...) We already had that discussion in December: https://patchwork.kernel.org/project/linux-usb/patch/d9f8b9413c10fcf067658979d16a4f5c7abe69e7.camel@hadess.net/ Do you want me to reference this discussion somewhere? It's not an input device attribute because, in the rest of this patchset, the fact that it uses HID is an implementation detail. > > By default, the USB device will declare not to use a > > receiver/emitter. > > I do not understand this statement, what do you mean by this? That the default is for the wireless_status sysfs attribute not to be present, which means that the device isn't a receiver/emitter. I can remove that if it's confusing. > > > Signed-off-by: Bastien Nocera <hadess@hadess.net> > > --- > > Documentation/ABI/testing/sysfs-bus-usb | 12 ++++++ > > drivers/usb/core/sysfs.c | 50 > > +++++++++++++++++++++++++ > > drivers/usb/core/usb.h | 1 + > > include/linux/usb.h | 10 +++++ > > 4 files changed, 73 insertions(+) > > > > diff --git a/Documentation/ABI/testing/sysfs-bus-usb > > b/Documentation/ABI/testing/sysfs-bus-usb > > index 545c2dd97ed0..0bd22ece05cd 100644 > > --- a/Documentation/ABI/testing/sysfs-bus-usb > > +++ b/Documentation/ABI/testing/sysfs-bus-usb > > @@ -166,6 +166,18 @@ Description: > > The file will be present for all speeds of USB > > devices, and will > > always read "no" for USB 1.1 and USB 2.0 devices. > > > > +What: /sys/bus/usb/devices/<INTERFACE>/wireless_status > > +Date: January 2023 > > January was last month :( Sure. > > +Contact: Bastien Nocera <hadess@hadess.net> > > +Description: > > + Some USB devices use a small USB receiver coupled > > with a larger > > + wireless device, usually communicating using > > proprietary > > + wireless protocols. This attribute will read either > > "connected" > > + or "disconnected" depending on whether the emitter > > is turned on, > > + in range and connected, on the interface which is > > used to detect > > + this state. If the device does not use a > > receiver/emitter combo, > > + then this attribute will not exist. > > So would you declare a wireless network device such a thing? No, because the emitter and receiver together aren't considered a single device. > See, it gets tricky, I do not think this should be a generic USB > attribute at all. See above, it was already discussed. > > + > > What: /sys/bus/usb/devices/.../<hub_interface>/port<X> > > Date: August 2012 > > Contact: Lan Tianyu <tianyu.lan@intel.com> > > diff --git a/drivers/usb/core/sysfs.c b/drivers/usb/core/sysfs.c > > index 8217032dfb85..da3c0f0dd633 100644 > > --- a/drivers/usb/core/sysfs.c > > +++ b/drivers/usb/core/sysfs.c > > @@ -1232,9 +1232,59 @@ static const struct attribute_group > > intf_assoc_attr_grp = { > > .is_visible = intf_assoc_attrs_are_visible, > > }; > > > > +static ssize_t wireless_status_show(struct device *dev, > > + struct device_attribute *attr, > > char *buf) > > +{ > > + struct usb_interface *intf; > > + > > + intf = to_usb_interface(dev); > > + if (intf->wireless_status == > > USB_WIRELESS_STATUS_DISCONNECTED) > > + return sysfs_emit(buf, "%s\n", "disconnected"); > > + return sysfs_emit(buf, "%s\n", "connected"); > > +} > > +static DEVICE_ATTR_RO(wireless_status); > > + > > +static struct attribute *intf_wireless_status_attrs[] = { > > + &dev_attr_wireless_status.attr, > > + NULL > > +}; > > + > > +static umode_t intf_wireless_status_attr_is_visible(struct kobject > > *kobj, > > + struct attribute *a, int n) > > +{ > > + struct device *dev = kobj_to_dev(kobj); > > + struct usb_interface *intf = to_usb_interface(dev); > > + > > + if (a != &dev_attr_wireless_status.attr || > > + intf->wireless_status != USB_WIRELESS_STATUS_NA) > > + return a->mode; > > + return 0; > > +} > > + > > +static const struct attribute_group intf_wireless_status_attr_grp > > = { > > + .attrs = intf_wireless_status_attrs, > > + .is_visible = intf_wireless_status_attr_is_visible, > > +}; > > + > > +int usb_update_wireless_status_attr(struct usb_interface *intf) > > +{ > > + struct device *dev = &intf->dev; > > + int ret; > > + > > + ret = sysfs_update_group(&dev->kobj, > > &intf_wireless_status_attr_grp); > > + if (ret < 0) > > + return ret; > > + > > + sysfs_notify(&dev->kobj, NULL, "wireless_status"); > > + kobject_uevent(&dev->kobj, KOBJ_CHANGE); > > That could be very noisy, why does that deserve a KOBJ_CHANGE event? Because otherwise user-space can't know that the property either appeared or changed. This change only happens when the device is powered on or off while the receiver is plugged in, so this shouldn't happen at any excessive rate.
diff --git a/Documentation/ABI/testing/sysfs-bus-usb b/Documentation/ABI/testing/sysfs-bus-usb index 545c2dd97ed0..0bd22ece05cd 100644 --- a/Documentation/ABI/testing/sysfs-bus-usb +++ b/Documentation/ABI/testing/sysfs-bus-usb @@ -166,6 +166,18 @@ Description: The file will be present for all speeds of USB devices, and will always read "no" for USB 1.1 and USB 2.0 devices. +What: /sys/bus/usb/devices/<INTERFACE>/wireless_status +Date: January 2023 +Contact: Bastien Nocera <hadess@hadess.net> +Description: + Some USB devices use a small USB receiver coupled with a larger + wireless device, usually communicating using proprietary + wireless protocols. This attribute will read either "connected" + or "disconnected" depending on whether the emitter is turned on, + in range and connected, on the interface which is used to detect + this state. If the device does not use a receiver/emitter combo, + then this attribute will not exist. + What: /sys/bus/usb/devices/.../<hub_interface>/port<X> Date: August 2012 Contact: Lan Tianyu <tianyu.lan@intel.com> diff --git a/drivers/usb/core/sysfs.c b/drivers/usb/core/sysfs.c index 8217032dfb85..da3c0f0dd633 100644 --- a/drivers/usb/core/sysfs.c +++ b/drivers/usb/core/sysfs.c @@ -1232,9 +1232,59 @@ static const struct attribute_group intf_assoc_attr_grp = { .is_visible = intf_assoc_attrs_are_visible, }; +static ssize_t wireless_status_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct usb_interface *intf; + + intf = to_usb_interface(dev); + if (intf->wireless_status == USB_WIRELESS_STATUS_DISCONNECTED) + return sysfs_emit(buf, "%s\n", "disconnected"); + return sysfs_emit(buf, "%s\n", "connected"); +} +static DEVICE_ATTR_RO(wireless_status); + +static struct attribute *intf_wireless_status_attrs[] = { + &dev_attr_wireless_status.attr, + NULL +}; + +static umode_t intf_wireless_status_attr_is_visible(struct kobject *kobj, + struct attribute *a, int n) +{ + struct device *dev = kobj_to_dev(kobj); + struct usb_interface *intf = to_usb_interface(dev); + + if (a != &dev_attr_wireless_status.attr || + intf->wireless_status != USB_WIRELESS_STATUS_NA) + return a->mode; + return 0; +} + +static const struct attribute_group intf_wireless_status_attr_grp = { + .attrs = intf_wireless_status_attrs, + .is_visible = intf_wireless_status_attr_is_visible, +}; + +int usb_update_wireless_status_attr(struct usb_interface *intf) +{ + struct device *dev = &intf->dev; + int ret; + + ret = sysfs_update_group(&dev->kobj, &intf_wireless_status_attr_grp); + if (ret < 0) + return ret; + + sysfs_notify(&dev->kobj, NULL, "wireless_status"); + kobject_uevent(&dev->kobj, KOBJ_CHANGE); + + return 0; +} + const struct attribute_group *usb_interface_groups[] = { &intf_attr_grp, &intf_assoc_attr_grp, + &intf_wireless_status_attr_grp, NULL }; diff --git a/drivers/usb/core/usb.h b/drivers/usb/core/usb.h index 0eac7d4285d1..3f14e15f07f6 100644 --- a/drivers/usb/core/usb.h +++ b/drivers/usb/core/usb.h @@ -15,6 +15,7 @@ extern int usb_create_sysfs_dev_files(struct usb_device *dev); extern void usb_remove_sysfs_dev_files(struct usb_device *dev); extern void usb_create_sysfs_intf_files(struct usb_interface *intf); extern void usb_remove_sysfs_intf_files(struct usb_interface *intf); +extern int usb_update_wireless_status_attr(struct usb_interface *intf); extern int usb_create_ep_devs(struct device *parent, struct usb_host_endpoint *endpoint, struct usb_device *udev); diff --git a/include/linux/usb.h b/include/linux/usb.h index 86d1c8e79566..517ae4b4e333 100644 --- a/include/linux/usb.h +++ b/include/linux/usb.h @@ -170,6 +170,12 @@ usb_find_last_int_out_endpoint(struct usb_host_interface *alt, return usb_find_common_endpoints_reverse(alt, NULL, NULL, NULL, int_out); } +enum usb_wireless_status { + USB_WIRELESS_STATUS_NA = 0, + USB_WIRELESS_STATUS_DISCONNECTED, + USB_WIRELESS_STATUS_CONNECTED, +}; + /** * struct usb_interface - what usb device drivers talk to * @altsetting: array of interface structures, one for each alternate @@ -203,6 +209,8 @@ usb_find_last_int_out_endpoint(struct usb_host_interface *alt, * @reset_ws: Used for scheduling resets from atomic context. * @resetting_device: USB core reset the device, so use alt setting 0 as * current; needs bandwidth alloc after reset. + * @wireless_status: if the USB device uses a receiver/emitter combo, whether + * the emitter is connected. * * USB device drivers attach to interfaces on a physical device. Each * interface encapsulates a single high level function, such as feeding @@ -253,6 +261,7 @@ struct usb_interface { unsigned needs_binding:1; /* needs delayed unbind/rebind */ unsigned resetting_device:1; /* true: bandwidth alloc after reset */ unsigned authorized:1; /* used for interface authorization */ + enum usb_wireless_status wireless_status; struct device dev; /* interface specific device info */ struct device *usb_dev; @@ -887,6 +896,7 @@ static inline int usb_interface_claimed(struct usb_interface *iface) extern void usb_driver_release_interface(struct usb_driver *driver, struct usb_interface *iface); + const struct usb_device_id *usb_match_id(struct usb_interface *interface, const struct usb_device_id *id); extern int usb_match_one_id(struct usb_interface *interface,
Add a wireless_status sysfs attribute to USB devices to keep track of whether a USB device that uses a receiver/emitter combo has its emitter connected or disconnected. By default, the USB device will declare not to use a receiver/emitter. Signed-off-by: Bastien Nocera <hadess@hadess.net> --- Documentation/ABI/testing/sysfs-bus-usb | 12 ++++++ drivers/usb/core/sysfs.c | 50 +++++++++++++++++++++++++ drivers/usb/core/usb.h | 1 + include/linux/usb.h | 10 +++++ 4 files changed, 73 insertions(+)