Commit 71472c0 (clk: add support for clock reparent on set_rate) added a
dereference of the new_parent pointer in clk_reparent(), but as detected
by smatch clk_reparent() later checks whether new_parent is NULL.
The dereference was in order to clear the new parent's new_child pointer
to avoid duplicate POST_RATE_CHANGE notifications, so clearly isn't
necessary if the new parent is NULL, so move it inside the "if
(new_parent)" block.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Currently of_clk_init() finds a matching device node while holding
the device tree spinlock. When a matching device node is found, the
lock is dropped and then re-acquired in order to get a reference
to the matching device id structure.
Acquiring the spinlock twice is unnecessary (and it opens a
vulnerable window that could conceivably lead to errors).
There already exists an interface for both finding and taking a
reference to a device id under lock, so use it.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Christian Daudt <csd@broadcom.com>
Reviewed-by: Markus Mayer <markus.mayer@linaro.org>
Reviewed-by: Matt Porter <matt.porter@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
At some point changes to clk_set_rate and clk_set_parent introduced a
bug whereby NULL struct clk pointers were treated as an error. This is
in violation of the API in include/linux/clk.h. Reintroduce graceful
handling of NULL clk's by bailing from clk_set_rate and clk_set_parent
with return codes of zero.
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Implement clk-mux remuxing if the CLK_SET_RATE_NO_REPARENT flag isn't
set. This implements determine_rate for clk-mux to propagate to each
parent and to choose the best one (like clk-divider this chooses the
parent which provides the fastest rate <= the requested rate).
The determine_rate op is implemented as a core helper function so that
it can be easily used by more complex clocks which incorporate muxes.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: Mike Turquette <mturquette@linaro.org>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Add core support to allow clock implementations to select the best
parent clock when rounding a rate, e.g. the one which can provide the
closest clock rate to that requested. This is by way of adding a new
clock op, determine_rate(), which is like round_rate() but has an extra
parameter to allow the clock implementation to optionally select a
different parent clock. The core then takes care of reparenting the
clock when setting the rate.
The parent change takes place with the help of some new private data
members. struct clk::new_parent specifies a clock's new parent (NULL
indicates no change), and struct clk::new_child specifies a clock's new
child (whose new_parent member points back to it). The purpose of these
are to allow correct walking of the future tree for notifications prior
to actually reparenting any clocks, specifically to skip child clocks
who are being reparented to another clock (they will be notified via the
new parent), and to include any new child clock. These pointers are set
by clk_calc_subtree(), and the new_child pointer gets cleared when a
child is actually reparented to avoid duplicate POST_RATE_CHANGE
notifications.
Each place where round_rate() is called, determine_rate() is checked
first and called in preference. This restructures a few of the call
sites to simplify the logic into if/else blocks.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: Mike Turquette <mturquette@linaro.org>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Move some parent related functions up in clk.c so they can be used by
the modifications in the following patch which enables clock reparenting
during set_rate. No other changes are made so this patch makes no
functional difference in isolation. This is separate from the following
patch primarily to ease readability of that patch.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: Mike Turquette <mturquette@linaro.org>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Mike Turquette <mturquette@linaro.org>
A clock's notifier count only reflects notifiers which are registered
directly for that clock. A reparent operation though affects the whole
subtree because of a potential rate change.
When issuing the pre rate change notifications only the notifier count
for the clock to be changed is considered and notifiers for subclocks
may never be called. Resulting in clocks in the subtree which have
registered notifiers, may receive a POST_- or ABORT_RATE_CHANGE
notification, without a PRE_RATE_CHANGE_NOTIFICATION.
Therefore always traverse the whole subtree when issueing pre rate
change notifications during a reparent operation.
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
clk_set_rate() uses clk->rate directly. This causes problems if the clock
is marked as CLK_GET_RATE_NOCACHE. Hence call clk_get_rate() to get the
current rate.
Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
debugfs uses the rate field directly. However this ignores the
CLK_GET_RATE_NOCACHE flag. Call clk_get_rate() instead.
Tested-by: Mark Zhang <markz@nvidia.com>
Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
With deferred probing, late_initcall() is too soon to declare a clock as
unused. Wait for deferred probing to finish before declaring a clock as
unused. Since deferred probing is done in late_initcall(), do the unused
check to late_initcall_sync.
Signed-off-by: Saravana Kannan <skannan@codeaurora.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Without this patch, the following race condition is possible.
* clk-A has two parents - clk-X and clk-Y.
* All three are disabled and clk-X is current parent.
* Thread A: clk_set_parent(clk-A, clk-Y).
* Thread A: <snip execution flow>
* Thread A: Grabs enable lock.
* Thread A: Sees enable count of clk-A is 0, so doesn't enable clk-Y.
* Thread A: Updates clk-A SW parent to clk-Y
* Thread A: Releases enable lock.
* Thread B: clk_enable(clk-A).
* Thread B: clk_enable() enables clk-Y, then enabled clk-A and returns.
clk-A is now enabled in software, but not clocking in hardware since the
hardware parent is still clk-X.
The only way to avoid race conditions between clk_set_parent() and
clk_enable/disable() is to ensure that clk_enable/disable() calls don't
require changes to hardware enable state between changes to software clock
topology and hardware clock topology.
The options to achieve the above are:
1. Grab the enable lock before changing software/hardware topology and
release it afterwards.
2. Keep the clock enabled for the duration of software/hardware topology
change so that any additional enable/disable calls don't try to change
the hardware state. Once the topology change is complete, the clock can
be put back in its original enable state.
Option (1) is not an acceptable solution since the set_parent() ops might
need to sleep.
Therefore, this patch implements option (2).
This patch doesn't violate any API semantics. clk_disable() doesn't
guarantee that the clock is actually disabled. So, no clients of a clock
can assume that a clock is disabled after their last call to clk_disable().
So, enabling the clock during a parent change is not a violation of any API
semantics.
This also has the nice side effect of simplifying the error handling code.
Signed-off-by: Saravana Kannan <skannan@codeaurora.org>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
[mturquette@linaro.org: fixed up whitespace issue]
There's no need to duplicate essentially the same functions. Let's
introduce static int pinctrl_pm_select_state() and make the other
related functions call that.
This allows us to add support later on for multiple active states,
and more optimized dynamic remuxing.
Note that we still need to export the various pinctrl_pm_select
functions as we want to keep struct pinctrl_state private to the
pinctrl code, and cannot replace those with inline functions.
Cc: Felipe Balbi <balbi@ti.com>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
The three functions pinctrl_pm_select_default_state,
pinctrl_pm_select_sleep_state, and pinctrl_pm_select_idle_state
are used in drivers that can be loadable modules, and should
be exported.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
If a device have sleep and idle states in addition to the
default state, look up these in the core and stash them in
the pinctrl state container.
Add accessor functions for pinctrl consumers to put the pins
into "default", "sleep" and "idle" states passing nothing but
the struct device * affected.
Solution suggested by Kevin Hilman, Mark Brown and Dmitry
Torokhov in response to a patch series from Hebbar
Gururaja.
Cc: Hebbar Gururaja <gururaja.hebbar@ti.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
In Rockchip Cortex-A9 based chips, they don't use paradigm of
reading-changing-writing the register contents. Instead they
use a hiword mask to indicate the changed bits.
When b1 should be set as gate, it also needs to indicate the change
by setting hiword mask (b1 << 16).
The patch adds gate flag for this usage.
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
In both Hisilicon & Rockchip Cortex-A9 based chips, they don't use the
paradigm of reading-changing-writing the register contents.
Instead they use a hiword mask to indicate the changed bits.
When b01 should be set as setting divider, it also needs to indicate
the change by setting hiword mask (b11 << 16).
The patch adds divider flag for this usage.
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
In both Hisilicon & Rockchip Cortex-A9 based chips, they don't use the
paradigm of reading-changing-writing the register contents.
Instead they use a hiword mask to indicate the changed bits.
When b01 should be set as switching mux, it also needs to indicate
the change by setting hiword mask (b11 << 16).
The patch adds mux flag for this usage.
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
The current implementation of desc_to_gpio() relies on the chip pointer
to be set to a valid value in order to compute the GPIO number. This
was done in the hope that we can get rid of the gpio_desc global array,
but this is not happening anytime soon.
This patch reimplements desc_to_gpio() in a fashion similar to that of
gpio_to_desc(). As a result, desc_to_gpio(gpio_to_desc(gpio)) == gpio is
now always true. This allows to call desc_to_gpio() on non-initialized
descriptors as some error-handling code currently does.
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Reported-by: Dr. H. Nikolaus Schaller <hns@goldelico.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Add #include <linux/device.h> to fix the following warning seen
with gcc 4.7.3:
In file included from drivers/staging/android/ion/ion_heap.c:26:0:
drivers/staging/android/ion/ion_priv.h:358:21: warning: ‘struct device’ declared inside parameter list [enabled by default]
drivers/staging/android/ion/ion_priv.h:358:21: warning: its scope is only this definition or declaration, which is probably not what you want [enabled by default]
Change-Id: Icc249b32d877a5b76b1669c99bef2b05d9e322da
Signed-off-by: John Stultz <john.stultz@linaro.org>
ion_test.h should not define ion_user_handle_t, and defining it
causes a warning:
In file included from drivers/staging/android/ion/ion_test.c:31:
drivers/staging/android/ion/../uapi/ion_test.h:23: error: redefinition of typedef 'ion_user_handle_t'
drivers/staging/android/ion/../uapi/ion.h:23: note: previous declaration of 'ion_user_handle_t' was here
Change-Id: I541897745a5ff128790a7e51b23f3034f5d3d6d9
Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Colin Cross <ccross@android.com>
ION doesn't export the proper symbols for it to be a module. This
causes build issues when ION is configured as a module.
Since Andorid kernels rarely use modules (I think recent policy
requires no modules?), go ahead and set the ION config to a bool
from the tristate option.
If folks decide ION as a module is important, we will have to go
through and export the various needed symbols.
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
TCPMSS is required for the Android Vpn service to correctly
handle the MTU on tun/ppp devices. Bug: 11579326
We don't really need SCHED_TRACER and the TIMER_STATS.
Change-Id: I10c5767a6324a496713752d4fe9eff361dc8e06a
(cherry picked from commit 23f01e8e81f3c53985958fa291b39c84293ad047)
