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 77ce544fa48deb7a2003f454624e3ca10d37ab87.
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 ace129d39b3107d330d4cf6934385d13521f2fec.
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 347df59f5d20fdf905afbc26b1328b0e28a8a01b.
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>
