From 836aedb1414d4724b2ec68dd19810960c593720c Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Thu, 24 Jan 2013 12:49:59 +0100 Subject: ACPI / PM: Expose power states of ACPI devices to user space Make it possible to retrieve the current power state of a device with ACPI power management from user space via sysfs by adding two new attributes, power_state and real_power_state, to the sysfs directory associated with the struct acpi_device object representing the device's ACPI node. Signed-off-by: Rafael J. Wysocki Acked-by: Greg Kroah-Hartman --- drivers/acpi/scan.c | 49 ++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 48 insertions(+), 1 deletion(-) (limited to 'drivers/acpi/scan.c') diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 8b3b18846c8c..9761d589f3f5 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -178,6 +178,32 @@ err_out: } EXPORT_SYMBOL(acpi_bus_hot_remove_device); +static ssize_t real_power_state_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct acpi_device *adev = to_acpi_device(dev); + int state; + int ret; + + ret = acpi_device_get_power(adev, &state); + if (ret) + return ret; + + return sprintf(buf, "%s\n", acpi_power_state_string(state)); +} + +static DEVICE_ATTR(real_power_state, 0444, real_power_state_show, NULL); + +static ssize_t power_state_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct acpi_device *adev = to_acpi_device(dev); + + return sprintf(buf, "%s\n", acpi_power_state_string(adev->power.state)); +} + +static DEVICE_ATTR(power_state, 0444, power_state_show, NULL); + static ssize_t acpi_eject_store(struct device *d, struct device_attribute *attr, const char *buf, size_t count) @@ -369,8 +395,22 @@ static int acpi_device_setup_files(struct acpi_device *dev) * hot-removal function from userland. */ status = acpi_get_handle(dev->handle, "_EJ0", &temp); - if (ACPI_SUCCESS(status)) + if (ACPI_SUCCESS(status)) { result = device_create_file(&dev->dev, &dev_attr_eject); + if (result) + return result; + } + + if (dev->flags.power_manageable) { + result = device_create_file(&dev->dev, &dev_attr_power_state); + if (result) + return result; + + if (dev->power.flags.power_resources) + result = device_create_file(&dev->dev, + &dev_attr_real_power_state); + } + end: return result; } @@ -380,6 +420,13 @@ static void acpi_device_remove_files(struct acpi_device *dev) acpi_status status; acpi_handle temp; + if (dev->flags.power_manageable) { + device_remove_file(&dev->dev, &dev_attr_power_state); + if (dev->power.flags.power_resources) + device_remove_file(&dev->dev, + &dev_attr_real_power_state); + } + /* * If device has _STR, remove 'description' file */ -- cgit