The PXA "CKEN" clock implements a mux with a set_parent hook, but
doesn't provide a determine_rate implementation.
This is a bit odd, since set_parent() is there to, as its name implies,
change the parent of a clock. However, the most likely candidates to
trigger that parent change are either the assigned-clock-parents device
tree property or a call to clk_set_rate(), with determine_rate()
figuring out which parent is the best suited for a given rate.
The other trigger would be a call to clk_set_parent(), but it's far less
used, and it doesn't look like there's any obvious user for that clock.
Similarly, it doesn't look like the device tree using that clock driver
uses any of the assigned-clock properties on that clock.
So, the set_parent hook is effectively unused, possibly because of an
oversight. However, it could also be an explicit decision by the
original author to avoid any reparenting but through an explicit call to
clk_set_parent().
The latter case would be equivalent to setting the determine_rate
implementation to clk_hw_determine_rate_no_reparent(). Indeed, if no
determine_rate implementation is provided, clk_round_rate() (through
clk_core_round_rate_nolock()) will call itself on the parent if
CLK_SET_RATE_PARENT is set, and will not change the clock rate
otherwise.
And if it was an oversight, then we are at least explicit about our
behavior now and it can be further refined down the line.
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20221018-clk-range-checks-fixes-v4-30-971d5077e7d2@cerno.tech
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
kzalloc() is a memory allocation function which can return NULL when
some internal memory errors happen. So it is better to check it to
prevent potential wrong memory access.
Signed-off-by: Xiaoke Wang <xkernel.wang@foxmail.com>
Link: https://lore.kernel.org/r/tencent_2B9817738F38B02844C245946EFF3B407E09@qq.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
The clock register definitions are now used (almost) exclusively in the
clk driver, and that relies on no other mach/*.h header files any more.
Remove the dependency on mach/pxa*-regs.h by addressing the registers
as offsets from a void __iomem * pointer, which is either passed from
a board file, or (for the moment) ioremapped at boot time from a hardcoded
address in case of DT (this should be moved into the DT of course).
Cc: linux-clk@vger.kernel.org
Acked-by: Stephen Boyd <sboyd@kernel.org>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
The get_sdram_rows() and get_memclkdiv() helpers need smemc
register that are separate from the clk registers, move
them out of the clk driver, and use an extern declaration
instead.
Cc: Michael Turquette <mturquette@baylibre.com>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: linux-clk@vger.kernel.org
Link: https://lore.kernel.org/lkml/87pnielzo4.fsf@belgarion.home/
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation version 2 of the license
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 315 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Armijn Hemel <armijn@tjaldur.nl>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531190115.503150771@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
These clk_ops structures are only passed to a call to
clk_register_composite where the corresponding parameters
are const, so the clk_ops structure can be const as well.
Identified and transformed using Coccinelle.
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
gcc-4.4 got confused by the inline assembler statement:
drivers/clk/pxa/clk-pxa.c: In function 'pxa2xx_core_turbo_switch':
drivers/clk/pxa/clk-pxa.c:152: error: expected string literal before ')' token
This removes the extraneous ':' to let all compilers parse the
driver correctly.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
This function is passed an __iomem pointer but we use a u32
pointer instead which makes checkers like spare complain.
Furthermore, "lock" is a pretty poor variable name for a string
that will go into lockdep reports and the symbol isn't marked
static. Cleanup all this.
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
The new pxa2xx_determine_rate() function seems lacking in a few
regards:
- For an exact match or no match at all, the rate is uninitialized
as reported by gcc -Wmaybe-unintialized:
drivers/clk/pxa/clk-pxa.c: In function 'pxa2xx_determine_rate':
drivers/clk/pxa/clk-pxa.c:243:5: error: 'rate' may be used uninitialized in this function
- If we get a non-exact match, the req->rate output is never set
to the actual rate but remains at the requested rate.
- We should not attempt to print a rate if none could be found
This rewrites the logic accordingly.
Fixes: 9fe6942950 ("clk: pxa: transfer CPU clock setting from pxa2xx-cpufreq")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
This is the initial stage to transfer the pxa25x and pxa27x CPU clocks
handling from cpufreq to the clock API. More precisely, the clocks
transferred are :
- cpll : core pll, known also as the CPU core turbo frequency
- core : core, known also as the CPU actual frequency, being either the
CPU core turbo frequency or the CPU core run frequency
This transfer is a prequel to shrink the code in pxa2xx-cpufreq.c, so
that it can become, at least in devicetree builds, the casual cpufreq-dt
driver.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Have each pxa variant (pxa25x, pxa27x, pxa3xx) have its own device-tree
clock initializing function, to be able to register its own specific
core clocks.
Apply that change specifically to pxa27x.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
As the clock descriptions are constant and only usefull at init time,
mark them as such by :
- spliting clock description (desc) and clock private data (dynamic)
- mark __initdata clock descriptions
This makes all the register and descriptions of the clocks to go after
kernel init phase.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
Add a the common code used by all PXA variants.
This is the first step in the transition from architecture defined
clocks (in arch/arm/mach-pxa) towards clock framework. The goal is to
have the same features (and not all the features) of the existing
clocks, and enable the transition of PXA to device-tree.
All PXA rely on a "CKEN" type clock, which :
- has a gate (bit in CKEN register)
- is generated from a PLL, generally divided
- has an alternate low power clock
Each variant will specialize the CKEN clock :
- pxa25x have no low power clock
- pxa27x in low power use always the 13 MHz ring oscillator
- pxa3xx in low power have specific dividers for each clock
The device-tree provides a list of CLK_* (ex: CLK_USB or CLK_I2C) to get
a handle on the clock. While pxa-clock.h will describe all the clocks of
all the variants, each variant will only use a subset of it.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
