In the hpet_ioctl_common() function, devp->hd_hpets is already cached in the
hpetp variable, so we can use just that.
Signed-off-by: NClemens Ladisch <clemens@ladisch.de>
Cc: Bob Picco <bob.picco@hp.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Fix two instances where a function would access the first HPET device instead
of the current one.
Signed-off-by: NClemens Ladisch <clemens@ladisch.de>
Cc: Bob Picco <bob.picco@hp.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Clear the ht_opaque field in the hpet_register() function before searching for
a free timer to prevent the function from incorrectly assuming that the search
succeeded afterwards.
Signed-off-by: NClemens Ladisch <clemens@ladisch.de>
Cc: Bob Picco <bob.picco@hp.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Fix a division by zero that happened when the HPET_INFO ioctl was called
before a timer frequency had been set.
Signed-off-by: NClemens Ladisch <clemens@ladisch.de>
Cc: Bob Picco <bob.picco@hp.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Fix a wrong memory access in hpet_ioctl_common().  It was not possible to use
the HPET_INFO ioctl from kernel space because it always called copy_to_user().
Signed-off-by: NClemens Ladisch <clemens@ladisch.de>
Cc: Bob Picco <bob.picco@hp.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch adds support for shared HPET interrupts.

The driver previously acknowledged interrupts for both edge and level
interrupts, but didn't actually allow a shared interrupt in the latter case.

We use a new per-timer flag to save whether the timer's interrupt might be
shared, and use it to do the processing required for level interrupts only if
necessary.
Signed-off-by: NClemens Ladisch <clemens@ladisch.de>
Acked-by: NBob Picco <bob.picco@hp.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

It was only the RTC hardware that restricted interrupt frequencies to a power
of two.  There is no reason to take over this restriction into the HPET
driver, so remove the offending check.
Signed-off-by: NClemens Ladisch <clemens@ladisch.de>
Acked-by: NBob Picco <bob.picco@hp.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch removes several reads of a timer's config register that serve no
purpose whatsoever.
Signed-off-by: NClemens Ladisch <clemens@ladisch.de>
Acked-by: NBob Picco <bob.picco@hp.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The variable hpet_ntimer is never read, so remove it.
Signed-off-by: NClemens Ladisch <clemens@ladisch.de>
Acked-by: NBob Picco <bob.picco@hp.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

On 32-bit architectures, the multiplication in the argument for
hpet_time_div() often overflows.  In the typical case of a 14.32 MHz timer,
this happens when the desired frequency exceeds 61 Hz.

To avoid this multiplication, we can precompute and store the hardware
timer frequency, instead of the period, in the device structure, which
leaves us with a simple division when computing the number of timer ticks.

As a side effect, this also removes a theoretical bug where the timer
interpolator's frequency would be computed as a 32-bit value even if the
HPET frequency is greater than 2^32 Hz (the HPET spec allows up to 10 GHz).
Signed-off-by: NClemens Ladisch <clemens@ladisch.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Disallow setting an interrupt frequency of zero (which would result in a
division by zero), and disallow enabling the interrupt when the frequency
hasn't yet been set (which would use an interrupt period of zero).
Signed-off-by: NClemens Ladisch <clemens@ladisch.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The address passed to io_remap_pfn_range() in hpet_mmap() does not need to
be converted using __pa(): it is already a physical address.  This bug was
found and the patch suggested by Clay Harris.

I introduced this particular bug when making io_remap_pfn_range changes a
few months ago.  In fact mmap()ing /dev/hpet has *never* previously worked:
before my changes __pa() was being executed on an ioremap()ed virtual
address, which is also invalid.
Signed-off-by: NKeir Fraser <keir@xensource.com>
Cc: Robert Picco <Robert.Picco@hp.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

With gcc -W:

drivers/char/hpet.c:102: warning: `inline' is not at beginning of declaration
drivers/char/hpet.c:109: warning: `inline' is not at beginning of declaration
Signed-off-by: NJesper Juhl <juhl-lkml@dif.dk>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The HPET driver is using a parts per second drift factor instead of the
standard parts per million drift the time interpolator code expects.  This
patch fixes that problem and updates the URL for the HPET spec.
Signed-off-by: NAlex Williamson <alex.williamson@hp.com>
Cc: "Robert W. Picco" <bob.picco@hp.com>
Acked-by: N"Pallipadi, Venkatesh" <venkatesh.pallipadi@intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NKenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLen Brown <len.brown@intel.com>

We don't need to use do_div() on a 32-bit quantity.
Signed-off-by: NJon Smirl <jonsmirl@gmail.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!