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  1. 13 5月, 2009 1 次提交
  3. 24 4月, 2009 2 次提交
    • P
      OMAP2/3 GPTIMER: allow system tick GPTIMER to be changed in board-*.c files · f248076c
      由 Paul Walmsley 提交于 
      Add a function omap2_gp_clockevent_set_gptimer() for board-*.c files
to use in .init_irq functions to configure the system tick GPTIMER.
Practical choices at this point are GPTIMER1 or GPTIMER12.  Both of
these timers are in the WKUP powerdomain, and so are unaffected by
chip power management.  GPTIMER1 can use sys_clk as a source, for
applications where a high-resolution timer is more important than
power management.  GPTIMER12 has the special property that it has the
secure 32kHz oscillator as its source clock, which may be less prone
to glitches than the off-chip 32kHz oscillator.  But on HS devices, it
may not be available for Linux use.

It appears that most boards are fine with GPTIMER1, but BeagleBoard
should use GPTIMER12 when using a 32KiHz timer source, due to hardware bugs
in revisions B4 and below.  Modify board-omap3beagle.c to use GPTIMER12.

This patch originally used a Kbuild config option to select the GPTIMER,
but was changed to allow this to be specified in board-*.c files, per
Tony's request.

Kalle Vallo <kalle.valo@nokia.com> found a bug in an earlier version of
this patch - thanks Kalle.

Tested on Beagle rev B4 ES2.1, with and without CONFIG_OMAP_32K_TIMER, and
3430SDP.
Signed-off-by: NPaul Walmsley <paul@pwsan.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>
Cc: Kalle Valo <kalle.valo@nokia.com>
      f248076c
    • P
      OMAP2xxx clock: fix broken cpu_mask code · 15ca78f7
      由 Paul Walmsley 提交于 
      Commit 8ad8ff65 breaks the OMAP2xxx
cpu_mask code, which causes OMAP2xxx to panic on boot.  Fix by
removing the cpu_mask auto variable and by changing CK_242X
and CK_243X to use RATE_IN_242X/RATE_IN_243X.

Resolves

<1>Unable to handle kernel NULL pointer dereference at virtual address 0000000c
<1>pgd = c0004000
<1>[0000000c] *pgd=00000000
Internal error: Oops: 5 [#1]
Modules linked in:
CPU: 0    Not tainted  (2.6.29-omap1 #32)
PC is at omap2_clk_set_parent+0x104/0x120
LR is at omap2_clk_set_parent+0x28/0x120
Signed-off-by: NPaul Walmsley <paul@pwsan.com>
Tested-by: NJarkko Nikula <jarkko.nikula@nokia.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
      15ca78f7
  5. 23 4月, 2009 1 次提交
    • P
      OMAP2xxx clock: pre-initialize struct clks early · c8088112
      由 Paul Walmsley 提交于 
      Commit 3f0a820c breaks OMAP2xxx boot
during initial propagate_rate() on osc_ck and sys_ck.  Fix by
pre-initializing all struct clks before running any other clock init
code.  Incorporates review comments from Russell King
<rmk+kernel@arm.linux.org.uk>.

Resolves

<1>Unable to handle kernel NULL pointer dereference at virtual address 00000000
<1>pgd = c0004000
<1>[00000000] *pgd=00000000
Internal error: Oops: 5 [#1]
Modules linked in:
CPU: 0    Not tainted  (2.6.29-omap1 #37)
PC is at propagate_rate+0x10/0x60
LR is at omap2_clk_init+0x30/0x218
...
Signed-off-by: NPaul Walmsley <paul@pwsan.com>
Tested-by: NJarkko Nikula <jarkko.nikula@nokia.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
      c8088112
  7. 20 2月, 2009 1 次提交
    • R
      [ARM] omap: add support for bypassing DPLLs · c0bf3132
      由 Russell King 提交于 
      This roughly corresponds with OMAP commits: 7d06c48, 3241b19,
88b5d9b, 18a5500, 9c909ac, 5c6497b, 8b1f0bd, 2ac1da8.

For both OMAP2 and OMAP3, we note the reference and bypass clocks in
the DPLL data structure.  Whenever we modify the DPLL rate, we first
ensure that both the reference and bypass clocks are enabled.  Then,
we decide whether to use the reference and DPLL, or the bypass clock
if the desired rate is identical to the bypass rate, and program the
DPLL appropriately.  Finally, we update the clock's parent, and then
disable the unused clocks.

This keeps the parents correctly balanced, and more importantly ensures
that the bypass clock is running whenever we reprogram the DPLL.  This
is especially important because the procedure for reprogramming the DPLL
involves switching to the bypass clock.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
      c0bf3132
  9. 14 2月, 2009 1 次提交
    • R
      [ARM] omap: arrange for clock recalc methods to return the rate · 8b9dbc16
      由 Russell King 提交于 
      linux-omap source commit 33d000c99ee393fe2042f93e8422f94976d276ce
introduces a way to "dry run" clock changes before they're committed.
However, this involves putting logic to handle this into each and
every recalc function, and unfortunately due to the caching, led to
some bugs.

Solve both of issues by making the recalc methods always return the
clock rate for the clock, which the caller decides what to do with.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
      8b9dbc16
  11. 09 2月, 2009 20 次提交
  13. 02 2月, 2009 1 次提交
  15. 06 9月, 2008 2 次提交
  17. 07 8月, 2008 1 次提交
  19. 03 7月, 2008 1 次提交
    • P
      ARM: OMAP2: Clock: New OMAP2/3 DPLL rate rounding algorithm · 88b8ba90
      由 Paul Walmsley 提交于 
      This patch adds a new rate rounding algorithm for DPLL clocks on the
OMAP2/3 architecture.

For a desired DPLL target rate, there may be several
multiplier/divider (M, N) values which will generate a sufficiently
close rate.  Lower N values result in greater power economy.  However,
lower N values can cause the difference between the rounded rate and
the target rate ("rate error") to be larger than it would be with a
higher N.  This can cause downstream devices to run more slowly than
they otherwise would.

This DPLL rate rounding algorithm:

- attempts to find the lowest possible N (DPLL divider) to reach the
  target_rate (since, according to Richard Woodruff <r-woodruff@ti.com>,
  lower N values save more power than higher N values).

- allows developers to set an upper bound on the error between the
  rounded rate and the desired target rate ("rate tolerance"), so an
  appropriate balance between rate fidelity and power savings can be
  set.  This maximum rate error tolerance is set via
  omap2_set_dpll_rate_tolerance().

- never returns a rounded rate higher than the target rate.

The rate rounding algorithm caches the last rounded M, N, and rate
computation to avoid rounding the rate twice for each clk_set_rate()
call.  (This patch does not yet implement set_rate for DPLLs; that
follows in a future patch.)

The algorithm trades execution speed for rate accuracy.  It will find
the (M, N) set that results in the least rate error, within a
specified rate tolerance.  It does this by evaluating each divider
setting - on OMAP3, this involves 128 steps.  Another approach to DPLL
rate rounding would be to bail out as soon as a valid rate is found
within the rate tolerance, which would trade rate accuracy for
execution speed.  Alternate implementations welcome.

This code is not yet used by the OMAP24XX DPLL clock, since it
is currently defined as a composite clock, fusing the DPLL M,N and the
M2 output divider.  This patch also renames the existing OMAP24xx DPLL
programming functions to highlight that they program both the DPLL and
the DPLL's output multiplier.
Signed-off-by: NPaul Walmsley <paul@pwsan.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>
      88b8ba90
  21. 15 4月, 2008 5 次提交
  23. 31 10月, 2007 1 次提交
  25. 22 8月, 2007 1 次提交
  27. 21 5月, 2007 1 次提交
  29. 07 3月, 2007 1 次提交