From 2aa1e462508d73e4fa2de26a3d50c867bb784830 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Mon, 29 Dec 2025 14:29:59 +0100 Subject: [PATCH] ACPI: sysfs: Add device cid attribute for exposing _CID lists Add a new sysfs attribute called "cid" under struct acpi_device for exposing the list of compatible device IDs returned by the device's _CID object, if present. The new attribute will be present only if the _CID object is present. Signed-off-by: Rafael J. Wysocki Reviewed-by: Andy Shevchenko Link: https://patch.msgid.link/5957407.DvuYhMxLoT@rafael.j.wysocki --- drivers/acpi/device_sysfs.c | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) diff --git a/drivers/acpi/device_sysfs.c b/drivers/acpi/device_sysfs.c index cd199fbe4dc90..8cc9507b3c6de 100644 --- a/drivers/acpi/device_sysfs.c +++ b/drivers/acpi/device_sysfs.c @@ -403,6 +403,33 @@ hid_show(struct device *dev, struct device_attribute *attr, char *buf) } static DEVICE_ATTR_RO(hid); +static ssize_t cid_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct acpi_device *acpi_dev = to_acpi_device(dev); + struct acpi_device_info *info = NULL; + ssize_t len = 0; + + acpi_get_object_info(acpi_dev->handle, &info); + if (!info) + return 0; + + if (info->valid & ACPI_VALID_CID) { + struct acpi_pnp_device_id_list *cid_list = &info->compatible_id_list; + int i; + + for (i = 0; i < cid_list->count - 1; i++) + len += sysfs_emit_at(buf, len, "%s,", cid_list->ids[i].string); + + len += sysfs_emit_at(buf, len, "%s\n", cid_list->ids[i].string); + } + + kfree(info); + + return len; +} +static DEVICE_ATTR_RO(cid); + static ssize_t uid_show(struct device *dev, struct device_attribute *attr, char *buf) { @@ -520,6 +547,7 @@ static DEVICE_ATTR_RO(status); static struct attribute *acpi_attrs[] = { &dev_attr_path.attr, &dev_attr_hid.attr, + &dev_attr_cid.attr, &dev_attr_modalias.attr, &dev_attr_description.attr, &dev_attr_adr.attr, @@ -562,6 +590,9 @@ static bool acpi_show_attr(struct acpi_device *dev, const struct device_attribut if (attr == &dev_attr_status) return acpi_has_method(dev->handle, "_STA"); + if (attr == &dev_attr_cid) + return acpi_has_method(dev->handle, "_CID"); + /* * If device has _EJ0, 'eject' file is created that is used to trigger * hot-removal function from userland. -- 2.47.3