Commit 923d4a45 authored by Lv Zheng's avatar Lv Zheng Committed by Rafael J. Wysocki
Browse files

ACPI: Add user space interface for identification objects 



ACPI devices are glued with physical devices through _ADR object, ACPI
enumerated devices are identified with _UID object.  Currently we can
observe _HID/_CID through sysfs interfaces (hid/modalias), but there's
no way for us to check _ADR/_UID from user space.  This patch closes
this gap for ACPI developers and users.

[rjw: Modified the subject and changelog slightly.]
Signed-off-by: default avatarLv Zheng <lv.zheng@intel.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent ccf78040

drivers/acpi/scan.c

+28 −0
Original line number Diff line number Diff line
@@ -220,6 +220,25 @@ acpi_device_hid_show(struct device *dev, struct device_attribute *attr, char *bu 
}

static DEVICE_ATTR(hid, 0444, acpi_device_hid_show, NULL);



static ssize_t acpi_device_uid_show(struct device *dev,

				    struct device_attribute *attr, char *buf)

{

	struct acpi_device *acpi_dev = to_acpi_device(dev);



	return sprintf(buf, "%s\n", acpi_dev->pnp.unique_id);

}

static DEVICE_ATTR(uid, 0444, acpi_device_uid_show, NULL);



static ssize_t acpi_device_adr_show(struct device *dev,

				    struct device_attribute *attr, char *buf)

{

	struct acpi_device *acpi_dev = to_acpi_device(dev);



	return sprintf(buf, "0x%08x\n",

		       (unsigned int)(acpi_dev->pnp.bus_address));

}

static DEVICE_ATTR(adr, 0444, acpi_device_adr_show, NULL);



static ssize_t

acpi_device_path_show(struct device *dev, struct device_attribute *attr, char *buf) {

	struct acpi_device *acpi_dev = to_acpi_device(dev);
@@ -304,6 +323,11 @@ static int acpi_device_setup_files(struct acpi_device *dev) 
			goto end;

	}



	if (dev->flags.bus_address)

		result = device_create_file(&dev->dev, &dev_attr_adr);

	if (dev->pnp.unique_id)

		result = device_create_file(&dev->dev, &dev_attr_uid);



        /*

         * If device has _EJ0, 'eject' file is created that is used to trigger

         * hot-removal function from userland.
@@ -335,6 +359,10 @@ static void acpi_device_remove_files(struct acpi_device *dev) 
	if (ACPI_SUCCESS(status))

		device_remove_file(&dev->dev, &dev_attr_eject);



	if (dev->pnp.unique_id)

		device_remove_file(&dev->dev, &dev_attr_uid);

	if (dev->flags.bus_address)

		device_remove_file(&dev->dev, &dev_attr_adr);

	device_remove_file(&dev->dev, &dev_attr_modalias);

	device_remove_file(&dev->dev, &dev_attr_hid);

	if (dev->handle)

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