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authorChris Bagwell <chris@cnpbagwell.com>2010-10-12 03:47:18 +0400
committerMatthew Garrett <mjg@redhat.com>2010-10-21 18:10:53 +0400
commit7f80d734b3b5d23b9851cc03cc20733bca2c724e (patch)
tree406b97e43f8e2db6ab7ca5cf3433e41532f9e699 /drivers/platform
parenteda1748418beb1b9a75d0cea3304edf922c66134 (diff)
downloadlinux-7f80d734b3b5d23b9851cc03cc20733bca2c724e.tar.xz
eeepc-wmi: Add cpufv sysfs interface
eeepc-laptop provides a sysfs interface to read and control what it calls cpufv. When WMI is enabled, the ACPI interface changes slightly and becames a write-only control with 3 valid values. Expose cpufv again to allow for user space utils that can extended battery life noticably and come a little closer to parity with eeepc-laptop. Write-only is OK for most user space apps because read status was mostly used to prevent unneeded mode changes. Since this same check to ignore changes to same mode also exists in the DSDT then it was wasted ACPI call. acpi_osi="!Windows 2009" can be used for get back eeepc-laptop's read support of cpufv for debugging things such as behaviour during resume. This patch was tested with EEE PC 1005PE by monitoring powertop output while writing values of "0", "1", and "2" and by reviewing the decompiled DSDT of an 1201NL and comparing it to 1005PE's DSDT. Signed-off-by: Chris Bagwell <chris@cnpbagwell.com> Signed-off-by: Matthew Garrett <mjg@redhat.com>
Diffstat (limited to 'drivers/platform')
-rw-r--r--drivers/platform/x86/eeepc-wmi.c51
1 files changed, 51 insertions, 0 deletions
diff --git a/drivers/platform/x86/eeepc-wmi.c b/drivers/platform/x86/eeepc-wmi.c
index 21df266c27ac..462ceab93f87 100644
--- a/drivers/platform/x86/eeepc-wmi.c
+++ b/drivers/platform/x86/eeepc-wmi.c
@@ -57,6 +57,7 @@ MODULE_ALIAS("wmi:"EEEPC_WMI_MGMT_GUID);
#define EEEPC_WMI_METHODID_DEVS 0x53564544
#define EEEPC_WMI_METHODID_DSTS 0x53544344
+#define EEEPC_WMI_METHODID_CFVS 0x53564643
#define EEEPC_WMI_DEVID_BACKLIGHT 0x00050012
@@ -297,6 +298,49 @@ static void eeepc_wmi_notify(u32 value, void *context)
kfree(obj);
}
+static int store_cpufv(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ int value;
+ struct acpi_buffer input = { (acpi_size)sizeof(value), &value };
+ acpi_status status;
+
+ if (!count || sscanf(buf, "%i", &value) != 1)
+ return -EINVAL;
+ if (value < 0 || value > 2)
+ return -EINVAL;
+
+ status = wmi_evaluate_method(EEEPC_WMI_MGMT_GUID,
+ 1, EEEPC_WMI_METHODID_CFVS, &input, NULL);
+
+ if (ACPI_FAILURE(status))
+ return -EIO;
+ else
+ return count;
+}
+
+static DEVICE_ATTR(cpufv, S_IRUGO | S_IWUSR, NULL, store_cpufv);
+
+static void eeepc_wmi_sysfs_exit(struct platform_device *device)
+{
+ device_remove_file(&device->dev, &dev_attr_cpufv);
+}
+
+static int eeepc_wmi_sysfs_init(struct platform_device *device)
+{
+ int retval = -ENOMEM;
+
+ retval = device_create_file(&device->dev, &dev_attr_cpufv);
+ if (retval)
+ goto error_sysfs;
+
+ return 0;
+
+error_sysfs:
+ eeepc_wmi_sysfs_exit(platform_device);
+ return retval;
+}
+
static int __devinit eeepc_wmi_platform_probe(struct platform_device *device)
{
struct eeepc_wmi *eeepc;
@@ -392,8 +436,14 @@ static int __init eeepc_wmi_init(void)
goto del_dev;
}
+ err = eeepc_wmi_sysfs_init(platform_device);
+ if (err)
+ goto del_sysfs;
+
return 0;
+del_sysfs:
+ eeepc_wmi_sysfs_exit(platform_device);
del_dev:
platform_device_del(platform_device);
put_dev:
@@ -408,6 +458,7 @@ static void __exit eeepc_wmi_exit(void)
{
struct eeepc_wmi *eeepc;
+ eeepc_wmi_sysfs_exit(platform_device);
eeepc = platform_get_drvdata(platform_device);
platform_driver_unregister(&platform_driver);
platform_device_unregister(platform_device);