On Mon, 17 Nov 2014, Javier Martinez Canillas wrote: > From: Bill Richardson <[email protected]> > > This adds some sysfs entries to provide userspace control of the > four-element LED "lightbar" on the Chromebook Pixel. This only instantiates > the lightbar controls if the device actually exists. > > To prevent DoS attacks, this interface is limited to 20 accesses/second, > although that rate can be adjusted by a privileged user. > > On Chromebooks without a lightbar, this should have no effect. On the > Chromebook Pixel, you should be able to do things like this: > > $ cd /sys/devices/virtual/chromeos/cros_ec/lightbar > $ echo 0x80 > brightness > $ echo 255 > brightness > $ > $ cat sequence > S0 > $ echo konami > sequence > $ cat sequence > KONAMI > $ > $ cat sequence > S0 > > And > > $ cd /sys/devices/virtual/chromeos/cros_ec/lightbar > $ echo stop > sequence > $ echo "4 255 255 255" > led_rgb > $ echo "0 255 0 0 1 0 255 0 2 0 0 255 3 255 255 0" > led_rgb > $ echo run > sequence > > Test the DoS prevention with this: > > $ cd /sys/devices/virtual/chromeos/cros_ec/lightbar > $ echo 500 > interval_msec > $ time (cat version version version version version version version) > > Signed-off-by: Bill Richardson <[email protected]> > Reviewed-by: Olof Johansson <[email protected]> > Tested-by: Doug Anderson <[email protected]> > Reviewed-by: Benson Leung <[email protected]> > Signed-off-by: Javier Martinez Canillas <[email protected]> > --- > drivers/mfd/Makefile | 2 +- > drivers/mfd/cros_ec_dev.c | 2 + > drivers/mfd/cros_ec_dev.h | 3 + > drivers/mfd/cros_ec_lightbar.c | 347 > +++++++++++++++++++++++++++++++++++++++++
By the sounds of the description, it doesn't seem as though this driver lives in MFD. I suggest another home, such as drivers/led. -- Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
