Commit Graph

7 Commits

Author SHA1 Message Date
Anas Nashif 3ae52624ff license: cleanup: add SPDX Apache-2.0 license identifier
Update the files which contain no license information with the
'Apache-2.0' SPDX license identifier.  Many source files in the tree are
missing licensing information, which makes it harder for compliance
tools to determine the correct license.

By default all files without license information are under the default
license of Zephyr, which is Apache version 2.

Signed-off-by: Anas Nashif <anas.nashif@intel.com>
2019-04-07 08:45:22 -04:00
Patrik Flykt 97b3bd11a7 drivers: Rename reserved function names
Rename reserved function names in drivers/ subdirectory. Update
function macros concatenatenating function names with '##'. As
there is a conflict between the existing gpio_sch_manage_callback()
and _gpio_sch_manage_callback() names, leave the latter unmodified.

Signed-off-by: Patrik Flykt <patrik.flykt@intel.com>
2019-04-03 17:31:00 -04:00
Andy Ross 987c0e5fc1 kernel: New timeout implementation
Now that the API has been fixed up, replace the existing timeout queue
with a much smaller version.  The basic algorithm is unchanged:
timeouts are stored in a sorted dlist with each node nolding a delta
time from the previous node in the list; the announce call just walks
this list pulling off the heads as needed.  Advantages:

* Properly spinlocked and SMP-aware.  The earlier timer implementation
  relied on only CPU 0 doing timeout work, and on an irq_lock() being
  taken before entry (something that was violated in a few spots).
  Now any CPU can wake up for an event (or all of them) and everything
  works correctly.

* The *_thread_timeout() API is now expressible as a clean wrapping
  (just one liners) around the lower-level interface based on function
  pointer callbacks.  As a result the timeout objects no longer need
  to store backpointers to the thread and wait_q and have shrunk by
  33%.

* MUCH smaller, to the tune of hundreds of lines of code removed.

* Future proof, in that all operations on the queue are now fronted by
  just two entry points (_add_timeout() and z_clock_announce()) which
  can easily be augmented with fancier data structures.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
2018-10-16 15:03:10 -04:00
Andy Ross 96013b0375 system_timer.h: Change "now" uptime API to be simpler for drivers
The current z_clock_uptime() call (recently renamed from
_get_elapsed_program_time) requires the driver to track a full 64 bit
uptime value in ticks, which is entirely separate from the one the
kernel is already keeping.

Don't do that.  Just ask the drivers to track uptime since the last
call to z_clock_announce(), since that is going to map better to
built-in hardware capability.

Obviously existing drivers already have this feature, so they're
actually getting slightly larger in order to implement the new API in
terms of the old one.  But future drivers will thank us.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
2018-10-16 15:03:10 -04:00
Andy Ross 722a888ef7 timer: Clean up hairy tickless APIs
The tickless driver had a bunch of "hairy" APIs which forced the timer
drivers to do needless low-level accounting for the benefit of the
kernel, all of which then proceeded to implement them via cut and
paste.  Specifically the "program_time" calls forced the driver to
expose to the kernel exactly when the next interrupt was due and how
much time had elapsed, in a parallel API to the existing "what time is
it" and "announce a tick" interrupts that carry the same information.

Remove these from the kernel, replacing them with synthesized logic
written in terms of the simpler APIs.

In some cases there will be a performance impact due to the use of the
64 bit uptime call, but that will go away soon.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
2018-10-16 15:03:10 -04:00
Andy Ross 1a1a9539ea include/system_timer.h: Timer API cleanup
Rename timer driver API functions to be consistent.  ADD DOCS TO THE
HEADER so implementations understand what the requirements are.
Remove some unused functions that don't need declarations here.

Also removes the per-platform #if's around the power control callback
in favor of a weak-linked noop function in the driver initialization
(adds a few bytes of code to default platforms -- we'll live, I
think).

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
2018-10-16 15:03:10 -04:00
Andy Ross ab488277bc drivers/timer: Unify timeout setting APIs
The existing API had two almost identical functions: _set_time() and
_timer_idle_enter().  Both simply instruct the timer driver to set the
next timer interrupt expiration appropriately so that the call to
z_clock_announce() will be made at the requested number of ticks.  On
most/all hardware, these should be implementable identically.

Unfortunately because they are specified differently, existing drivers
have implemented them in parallel.

Specify a new, unified, z_clock_set_timeout().  Document it clearly
for implementors.  And provide a shim layer for legacy drivers that
will continue to use the old functions.

Note that this patch fixes an existing bug found by inspection: the
old call to _set_time() out of z_clock_announce() failed to test for
the "wait forever" case in the situation where clock_always_on is
true, meaning that a system that reached this point and then never set
another timeout would freeze its uptime clock incorrectly.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
2018-10-16 15:03:10 -04:00