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: Russell King <rmk+kernel@arm.linux.org.uk>
linux-omap source commit 33d000c99e
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: Russell King <rmk+kernel@arm.linux.org.uk>
Clock rate change code executes inside a spinlock with hardirqs
disabled. The only code that should be messing around with the
hardirq state should be the plat-omap/clock.c code. In the
omap2_reprogram_dpllcore() case, this probably just wastes cycles, but
in the omap3_core_dpll_m2_set_rate() case, this is a nasty bug.
linux-omap source commit is b9b6208dad.
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Traditionally, we've tracked the parent/child relationships between
clk structures by setting the child's parent member to point at the
upstream clock. As a result, when decending the tree, we have had
to scan all clocks to find the children.
Avoid this wasteful scanning by keeping a list of the clock's children.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This implements the remainder of:
OMAP clock: move rate recalc, propagation code up to plat-omap/clock.c
from Paul Walmsley which is not covered by the previous:
[ARM] omap: move clock propagation into core omap clock code
[ARM] omap: remove unnecessary calls to propagate_rate()
[ARM] omap: move propagate_rate() calls into generic omap clock code
commits.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Use the standard clk_set_rate() function in omap2_clk_arch_init()
rather than omap2_select_table_rate() -- this will ensure that clock
rates are recalculated and propagated correctly after those operations
are consolidated into clk_set_rate().
linux-omap source commit is 03c0333001.
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Separate SDRC code common to OMAP2/3 from mach-omap2/sdrc2xxx.c to
mach-omap2/sdrc.c. Rename the OMAP2xxx-specific functions to use an
'omap2xxx' prefix rather than an 'omap2' prefix, and use "sdrc" in the
function names rather than "memory." Mark several functions
as static that should not be used outside the sdrc2xxx.c file.
linux-omap source commit is bf1612b9d8.
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Move the contents of the arch/arm/mach-omap2/memory.h file to the
existing mach/sdrc.h file, and remove memory.h. Modify files which
include memory.h to include asm/arch/sdrc.h instead.
linux-omap source commit is e7ae2d8992.
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch adds a CPUfreq frequency-table implementation for OMAP2 by
walking the PRCM rate-table for available entries and adding them to a
CPUfreq table.
CPUfreq can then be used to manage switching between all the available
entries in the PRCM rate table. Either use the CPUfreq sysfs
interface directly, (see Section 3 of Documentation/cpu-freq/user-guide.txt)
or use the cpufrequtils package:
http://www.kernel.org/pub/linux/utils/kernel/cpufreq/cpufrequtils.html
Signed-off-by: Kevin Hilman <khilman@mvista.com>
Updated to try to use cpufreq_table if it exists.
linux-omap source commit is 77ce544fa4.
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch adds a missing OMAP24xx clock, the SSI L4 interface clock,
as "ssi_l4_ick".
linux-omap source commit is ace129d39b.
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Fix sparse & checkpatch warnings in OMAP2/3 PRCM & PM code. This mostly
consists of:
- converting pointer comparisons to integers in form similar to
(ptr == 0) to the standard idiom (!ptr)
- labeling a few non-static private functions as static
- adding prototypes for *_init() functions in the appropriate header
files, and getting rid of the corresponding open-coded extern
prototypes in other C files
- renaming the variable 'sclk' in mach-omap2/clock.c:omap2_get_apll_clkin
to avoid shadowing an earlier declaration
Clean up checkpatch issues. This mostly involves:
- converting some asm/ includes to linux/ includes
- cleaning up some whitespace
- getting rid of braces for conditionals with single following statements
Also take care of a few odds and ends, including:
- getting rid of unlikely() and likely() - none of this code is particularly
fast-path code, so the performance impact seems slim; and some of those
likely() and unlikely() indicators are probably not as accurate as the
ARM's branch predictor
- removing some superfluous casts
linux-omap source commit is 347df59f5d.
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Rather than introducing a special 'mcbsp_clk' with code behind it in
mach-omap*/mcbsp.c to handle the SoC specifics, arrange for the mcbsp
driver to be like any other driver. mcbsp requests its fck and ick
clocks directly, and the SoC specific code deals with selecting the
correct clock.
There is one oddity to deal with - OMAP1 fiddles with the DSP clocks
and DSP reset, so we move this to the two callback functions.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Convert OMAP MMC driver to match clocks using the device ID and a
connection ID rather than a clock name. This allows us to eliminate
the OMAP1/OMAP2 differences for the function clock.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
propagate_rate() is recursive, so it makes sense to minimise the
amount of stack which is used for each recursion. So, rather than
recursing back into it from the ->recalc functions if RATE_PROPAGATES
is set, do that test at the higher level.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Collect up all the common enable/disable clock operation functions
into a separate operations structure.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
This patch changes 24xx to use shared clock code and new register
access.
Note that patch adds some temporary OLD_CK defines to keep patch
more readable. These temporary defines will be removed in the next
patch. Also not all clocks are changed in this patch to limit the
size.
Also, the patch fixes few incorrect clock defines in clock24xx.h.
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
This patch moves clock.h to clock24xx.c to make room for
adding common clock code for 24xx and 34xx.
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Russell King