From 1b891f4c852817b3afd231712ab7e171932e1eb1 Mon Sep 17 00:00:00 2001 From: "Derek J. Clark" Date: Tue, 10 Mar 2026 07:29:19 +0000 Subject: include: device.h: Add named device attributes Adds DEVICE_ATTR_[RW|RO|WO]_NAMED macros for adding attributes that reuse the same sysfs name in a driver under separate subdirectories. When dealing with some devices it can be useful to be able to reuse the same name for similar attributes under a different subdirectory. For example, a single logical HID endpoint may provide a configuration interface for multiple physical devices. In such a case it is useful to provide symmetrical attribute names under different subdirectories on the configuration device. The Lenovo Legion Go is one such device, providing configuration to a detachable left controller, detachable right controller, the wireless transmission dongle, and the MCU. It is therefore beneficial to treat each of these as individual devices in the driver, providing a subdirectory for each physical device in the sysfs. As some attributes are reused by each physical device, it provides a much cleaner interface if the same driver can reuse the same attribute name in sysfs while uniquely distinguishing the store/show functions in the driver, rather than repeat string portions. Example new WO attrs: ATTRS{left_handle/reset}=="(not readable)" ATTRS{right_handle/reset}=="(not readable)" ATTRS{tx_dongle/reset}=="(not readable)" vs old WO attrs in a subdir: ATTRS{left_handle/left_handle_reset}=="(not readable)" ATTRS{right_handle/right_handle_reset}=="(not readable)" ATTRS{tx_dongle/tx_dongle_reset}=="(not readable)" or old WO attrs with no subdir: ATTRS{left_handle_reset}=="(not readable)" ATTRS{right_handle_reset}=="(not readable)" ATTRS{tx_dongle_reset}=="(not readable)" While the third option is usable, it doesn't logically break up the physical devices and creates a device directory with over 80 attributes once all attrs are defined. Reviewed-by: Mark Pearson Signed-off-by: Derek J. Clark Acked-by: Greg Kroah-Hartman Signed-off-by: Jiri Kosina --- include/linux/device.h | 46 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+) (limited to 'include') diff --git a/include/linux/device.h b/include/linux/device.h index 0be95294b6e6..381463baed6d 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -189,6 +189,22 @@ ssize_t device_show_string(struct device *dev, struct device_attribute *attr, #define DEVICE_ATTR_ADMIN_RW(_name) \ struct device_attribute dev_attr_##_name = __ATTR_RW_MODE(_name, 0600) +/** + * DEVICE_ATTR_RW_NAMED - Define a read-write device attribute with a sysfs name + * that differs from the function name. + * @_name: Attribute function preface + * @_attrname: Attribute name as it wil be exposed in the sysfs. + * + * Like DEVICE_ATTR_RW(), but allows for reusing names under separate paths in + * the same driver. + */ +#define DEVICE_ATTR_RW_NAMED(_name, _attrname) \ + struct device_attribute dev_attr_##_name = { \ + .attr = { .name = _attrname, .mode = 0644 }, \ + .show = _name##_show, \ + .store = _name##_store, \ + } + /** * DEVICE_ATTR_RO - Define a readable device attribute. * @_name: Attribute name. @@ -207,6 +223,21 @@ ssize_t device_show_string(struct device *dev, struct device_attribute *attr, #define DEVICE_ATTR_ADMIN_RO(_name) \ struct device_attribute dev_attr_##_name = __ATTR_RO_MODE(_name, 0400) +/** + * DEVICE_ATTR_RO_NAMED - Define a read-only device attribute with a sysfs name + * that differs from the function name. + * @_name: Attribute function preface + * @_attrname: Attribute name as it wil be exposed in the sysfs. + * + * Like DEVICE_ATTR_RO(), but allows for reusing names under separate paths in + * the same driver. + */ +#define DEVICE_ATTR_RO_NAMED(_name, _attrname) \ + struct device_attribute dev_attr_##_name = { \ + .attr = { .name = _attrname, .mode = 0444 }, \ + .show = _name##_show, \ + } + /** * DEVICE_ATTR_WO - Define an admin-only writable device attribute. * @_name: Attribute name. @@ -216,6 +247,21 @@ ssize_t device_show_string(struct device *dev, struct device_attribute *attr, #define DEVICE_ATTR_WO(_name) \ struct device_attribute dev_attr_##_name = __ATTR_WO(_name) +/** + * DEVICE_ATTR_WO_NAMED - Define a read-only device attribute with a sysfs name + * that differs from the function name. + * @_name: Attribute function preface + * @_attrname: Attribute name as it wil be exposed in the sysfs. + * + * Like DEVICE_ATTR_WO(), but allows for reusing names under separate paths in + * the same driver. + */ +#define DEVICE_ATTR_WO_NAMED(_name, _attrname) \ + struct device_attribute dev_attr_##_name = { \ + .attr = { .name = _attrname, .mode = 0200 }, \ + .store = _name##_store, \ + } + /** * DEVICE_ULONG_ATTR - Define a device attribute backed by an unsigned long. * @_name: Attribute name. -- cgit v1.2.3 From 6ca9029c823b7853e980585e757343e0e84227cd Mon Sep 17 00:00:00 2001 From: Mario Limonciello Date: Tue, 10 Mar 2026 07:29:27 +0000 Subject: HID: Include firmware version in the uevent Userspace software fwupd probes some HID devices when the daemon starts up to determine the current firmware version in order to be able to offer updated firmware if the manufacturer has made it available. In order to do this fwupd will detach the existing kernel driver if one is present, send a HID command and then reattach the kernel driver. This can be problematic if the user is using the HID device at the time that fwupd probes the hardware and can cause a few frames of input to be dropped. In some cases HID drivers already have a command to look up the firmware version, and so if that is exported to userspace fwupd can discover it and avoid needing to detach the kernel driver until it's time to update the device. Introduce a new member in the struct hid_device for the version and export a new uevent variable HID_FIRMWARE_VERSION that will display the version that HID drivers obtained. Reviewed-by: Derek J. Clark Reviewed-by: Mark Pearson Cc: Richard Hughes Signed-off-by: Mario Limonciello Signed-off-by: Jiri Kosina --- drivers/hid/hid-core.c | 5 +++++ include/linux/hid.h | 1 + 2 files changed, 6 insertions(+) (limited to 'include') diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c index 840a60113868..da57cbf0af26 100644 --- a/drivers/hid/hid-core.c +++ b/drivers/hid/hid-core.c @@ -2887,6 +2887,11 @@ static int hid_uevent(const struct device *dev, struct kobj_uevent_env *env) if (add_uevent_var(env, "MODALIAS=hid:b%04Xg%04Xv%08Xp%08X", hdev->bus, hdev->group, hdev->vendor, hdev->product)) return -ENOMEM; + if (hdev->firmware_version) { + if (add_uevent_var(env, "HID_FIRMWARE_VERSION=0x%04llX", + hdev->firmware_version)) + return -ENOMEM; + } return 0; } diff --git a/include/linux/hid.h b/include/linux/hid.h index 2990b9f94cb5..b0b70c05049d 100644 --- a/include/linux/hid.h +++ b/include/linux/hid.h @@ -698,6 +698,7 @@ struct hid_device { char name[128]; /* Device name */ char phys[64]; /* Device physical location */ char uniq[64]; /* Device unique identifier (serial #) */ + u64 firmware_version; /* Firmware version */ void *driver_data; -- cgit v1.2.3