With the removal of the chrdev_lock atomic flag, the counter-sysfs.c and
counter-chrdev.c no longer needs to include the atomic.h header file.
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Link: https://lore.kernel.org/r/20211021103514.955622-1-vilhelm.gray@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This removes the chrdev_lock from the counter subsystem. This was
intended to prevent opening the chrdev more than once. However, this
doesn't work in practice since userspace can duplicate file descriptors
and pass file descriptors to other processes. Since this protection
can't be relied on, it is best to just remove it.
Suggested-by: Greg KH <gregkh@linuxfoundation.org>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: David Lechner <david@lechnology.com>
Link: https://lore.kernel.org/r/20211017185521.3468640-1-david@lechnology.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch introduces a character device interface for the Counter
subsystem. Device data is exposed through standard character device read
operations. Device data is gathered when a Counter event is pushed by
the respective Counter device driver. Configuration is handled via ioctl
operations on the respective Counter character device node.
Cc: David Lechner <david@lechnology.com>
Cc: Gwendal Grignou <gwendal@chromium.org>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Link: https://lore.kernel.org/r/b8b8c64b4065aedff43699ad1f0e2f8d1419c15b.1632884256.git.vilhelm.gray@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
