From: Shem Multinymous This patch disables accelerometer power and stops its polling by the embedded controller upon suspend and module unload. The power saving is negligible, but it's the right thing to do. Signed-off-by: Shem Multinymous Signed-off-by: Pavel Machek Acked-by: Robert Love Signed-off-by: Andrew Morton --- drivers/hwmon/hdaps.c | 26 ++++++++++++++++++++++++++ 1 files changed, 26 insertions(+) diff -puN drivers/hwmon/hdaps.c~hdaps-power-off-accelerometer-on-suspend-and-unload drivers/hwmon/hdaps.c --- a/drivers/hwmon/hdaps.c~hdaps-power-off-accelerometer-on-suspend-and-unload +++ a/drivers/hwmon/hdaps.c @@ -373,6 +373,23 @@ good: return ret; } +/** + * hdaps_device_shutdown - power off the accelerometer + * Returns nonzero on failure. Can sleep. + */ +static int hdaps_device_shutdown(void) +{ + int ret; + ret = hdaps_set_power(0); + if (ret) { + printk(KERN_WARNING "hdaps: cannot power off\n"); + return ret; + } + ret = hdaps_set_ec_config(0, 1); + if (ret) + printk(KERN_WARNING "hdaps: cannot stop EC sampling\n"); + return ret; +} /* Device model stuff */ @@ -388,6 +405,12 @@ static int hdaps_probe(struct platform_d return 0; } +static int hdaps_suspend(struct platform_device *dev, pm_message_t state) +{ + hdaps_device_shutdown(); /* ignore errors, effect is negligible */ + return 0; +} + static int hdaps_resume(struct platform_device *dev) { return hdaps_device_init(); @@ -395,6 +418,7 @@ static int hdaps_resume(struct platform_ static struct platform_driver hdaps_driver = { .probe = hdaps_probe, + .suspend = hdaps_suspend, .resume = hdaps_resume, .driver = { .name = "hdaps", @@ -780,6 +804,7 @@ out_device: platform_device_unregister(pdev); out_driver: platform_driver_unregister(&hdaps_driver); + hdaps_device_shutdown(); out: printk(KERN_WARNING "hdaps: driver init failed (ret=%d)!\n", ret); return ret; @@ -789,6 +814,7 @@ static void __exit hdaps_exit(void) { del_timer_sync(&hdaps_timer); input_unregister_device(hdaps_idev); + hdaps_device_shutdown(); /* ignore errors, effect is negligible */ sysfs_remove_group(&pdev->dev.kobj, &hdaps_attribute_group); platform_device_unregister(pdev); platform_driver_unregister(&hdaps_driver); _