Commit Graph

6 Commits

Author SHA1 Message Date
Richard Cochran c3484c275d ptp: reduce stack usage when measuring the system time offset
This patch removes the large buffer from the stack of the system
offset ioctl and replaces it with a kmalloced buffer.

Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-11-26 17:22:14 -05:00
Richard Cochran c7ec0badcc ptp: reduce stack usage when reading external time stamps
This patch removes the large buffer from the stack of the read file
operation and replaces it with a kmalloced buffer.

Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-11-26 17:22:14 -05:00
Richard Cochran 215b13dd28 ptp: add an ioctl to compare PHC time with system time
This patch adds an ioctl for PTP Hardware Clock (PHC) devices that allows
user space to measure the time offset between the PHC and the system
clock. Rather than hard coding any kind of estimation algorithm into the
kernel, this patch takes the more flexible approach of just delivering
an array of raw clock readings. In that way, the user space clock servo
may be adapted to new and different hardware clocks.

Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Acked-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-11-01 11:41:34 -04:00
Dan Carpenter fb5a18cf7c ptp: Fix some locking bugs in ptp_read()
In ptp_read there is an unlock missing on an error path, and a double
unlock on another error path.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Acked-by: Richard Cochran <richard.cochran@omicron.at>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2011-06-01 19:29:10 -07:00
Dan Carpenter e23ef227d1 ptp: Return -EFAULT on copy_to_user() errors
copy_to_user() returns the number of bytes remaining, but we want a
negative error code in ptp_ioctl.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Acked-by: Richard Cochran <richard.cochran@omicron.at>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2011-06-01 19:29:08 -07:00
Richard Cochran d94ba80ebb ptp: Added a brand new class driver for ptp clocks.
This patch adds an infrastructure for hardware clocks that implement
IEEE 1588, the Precision Time Protocol (PTP). A class driver offers a
registration method to particular hardware clock drivers. Each clock is
presented as a standard POSIX clock.

The ancillary clock features are exposed in two different ways, via
the sysfs and by a character device.

Signed-off-by: Richard Cochran <richard.cochran@omicron.at>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2011-05-23 13:01:00 -07:00