From c713cd7f2d799c50a0721bf51d178ea9567215dd Mon Sep 17 00:00:00 2001 From: Srinivas Pandruvada Date: Fri, 10 Jan 2014 16:00:05 -0800 Subject: [PATCH] ACPI / scan: ACPI device object sysfs attribute for _STA evaluation This patch adds a "status" attribute for an ACPI device. This status attribute shows the value of the _STA object. The _STA object returns current status of an ACPI device: enabled, disabled, functioning, present. Signed-off-by: Srinivas Pandruvada [rjw: Subject and changelog] Signed-off-by: Rafael J. Wysocki --- drivers/acpi/scan.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 32b3401..c0f57ff 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -602,6 +602,20 @@ acpi_device_sun_show(struct device *dev, struct device_attribute *attr, } static DEVICE_ATTR(sun, 0444, acpi_device_sun_show, NULL); +static ssize_t status_show(struct device *dev, struct device_attribute *attr, + char *buf) { + struct acpi_device *acpi_dev = to_acpi_device(dev); + acpi_status status; + unsigned long long sta; + + status = acpi_evaluate_integer(acpi_dev->handle, "_STA", NULL, &sta); + if (ACPI_FAILURE(status)) + return -ENODEV; + + return sprintf(buf, "%llu\n", sta); +} +static DEVICE_ATTR_RO(status); + static int acpi_device_setup_files(struct acpi_device *dev) { struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL}; @@ -657,6 +671,12 @@ static int acpi_device_setup_files(struct acpi_device *dev) dev->pnp.sun = (unsigned long)-1; } + if (acpi_has_method(dev->handle, "_STA")) { + result = device_create_file(&dev->dev, &dev_attr_status); + if (result) + goto end; + } + /* * If device has _EJ0, 'eject' file is created that is used to trigger * hot-removal function from userland. @@ -712,6 +732,8 @@ static void acpi_device_remove_files(struct acpi_device *dev) 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 (acpi_has_method(dev->handle, "_STA")) + device_remove_file(&dev->dev, &dev_attr_status); if (dev->handle) device_remove_file(&dev->dev, &dev_attr_path); } -- 2.7.4