This patch cleans up arch/arm/mach-omap2/clkt_clksel.c. It:
- makes several functions static that are not called outside the file;
- adds documentation;
- makes some code paths easier to read (hopefully), by breaking up
compound statements and removing redundant checks;
- converts some pr_err()s that indicate clock tree data problems into WARN()s,
so they are more likely to be noticed;
- and moves omap2_clk_round_rate() back into mach-omap2/clock.c, its proper
home, since it is not clksel-specific.
Signed-off-by: Paul Walmsley <paul@pwsan.com>
The DEFAULT_RATE clksel_rate flag is essentially useless. It was set
on some of the lowest divisors, which, when switching to a much
higher-rate parent, could have potentially resulted in rates that
exceeded the hardware specifications for downstream clocks in the
window between the clk_set_parent(), and a subsequent clk_set_rate().
It seems much safer to just remove the flag and always use the highest
available divisor (resulting in the lowest possible rate) after the
switch, and this patch does so.
Ideally, it would be best to first attempt to switch to a divisor that
matches the clock's rate with the previous parent, if at all possible.
But that is a project for some other day or some other person. The
parent changing code is rarely used.
Signed-off-by: Paul Walmsley <paul@pwsan.com>
The RATE_FIXED clock flag is pointless. In the OMAP1 clock code, it
simply causes the omap1_clk_round_rate() function to return the
current rate of the clock. omap1_clk_round_rate(), however, should
never be called for a fixed-rate clock, since none of these clocks
have a .round_rate function pointer set in their struct clk records.
Similarly, in the OMAP2+ clock code, the RATE_FIXED flag just causes
the clock code to emit a warning if the OMAP clock maintainer was
foolish enough to add a .round_rate function pointer to a fixed-rate
clock. "Doctor, it hurts when I pretend that a fixed-rate clock is
rate-changeable." "Then don't pretend that a fixed-rate clock is
rate-changeable." It has no functional value. This patch drops the
RATE_FIXED clock flag, removing it from all clocks that are so marked.
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Richard Woodruff <r-woodruff2@ti.com>
All of the clocks that are marked with DELAYED_APP are changed as part
of the virt_prcm_set OPP virtual clock. On 24xx, these clocks all
need to be changed as part of a group to keep the clock tree
functional - hence the need for the VALID_CONFIG bit, which is not
present on later OMAPs. These clocks should not be rate-changed
independently. So prevent these clocks from being changed
independently by dropping their .round_rate and .set_rate function
pointers. It then turns out that the DELAYED_APP clock flag is no
longer useful, so drop it and the associated code and renumber the
clock flags.
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Richard Woodruff <r-woodruff2@ti.com>
Move all clksel-related clock functions from mach-omap2/clock.c to
mach-omap2/clkt_clksel.c. This is intended to make the clock code
easier to understand, since all of the functions needed to manage
clksel clocks are now located in their own file, rather than being
mixed with other, unrelated functions.
Clock debugging is also now more finely-grained, since the DEBUG macro
can now be defined for clksel clocks alon. This should reduce
unnecessary console noise when debugging.
Also, if at some future point the mach-omap2/ directory is split
into OMAP2/3/4 variants, this clkt file can be moved to the plat-omap/
directory to be shared.
Thanks to Alexander Shishkin <virtuoso@slind.org> for his comments to
improve the patch description.
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Alexander Shishkin <virtuoso@slind.org>
Paul Walmsley