Commit Graph

461 Commits

Author SHA1 Message Date
Tushar Behera
41ccf7f2d3 clk: samsung: Add MUX_FA macro to pass flag and alias
Cpufreq driver for some Samsung platforms have not yet been designed as
a platform driver, thereby they can only access clocks with an alias
name.

For EXYNOS4210, one such clock also requires a flag to be set, hence
there is a need to create another macro that can handle both flag and
alias.

Signed-off-by: Tushar Behera <tushar.behera@linaro.org>
Reviewed-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-06-22 10:50:41 -07:00
Heiko Stübner
646572c77d clk: add support for Rockchip gate clocks
This adds basic support for gate-clocks on Rockchip SoCs.
There are 16 gates in each register and use the HIWORD_MASK
mechanism for changing gate settings.

The gate registers form a continuos block which makes the dt node
structure a matter of taste, as either all 160 gates can be put into
one gate clock spanning all registers or they can be divided into
the 10 individual gates containing 16 clocks each.
The code supports both approaches.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-06-20 15:58:27 -07:00
Pawel Moll
c7f6e2d8ff clk: vexpress: Make the clock drivers directly available for arm64
The new arm64 architecture has no idea of platform or machine, so
it doesn't have to define ARCH_VEXPRESS configuration option at
all. To allow user to select the drivers at all, make it depend
on ARM64 as well.

Signed-off-by: Pawel Moll <pawel.moll@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-06-20 00:02:25 -07:00
Pawel Moll
e95a49b429 clk: vexpress: Use full node name to identify individual clocks
Previously all the clocks were reported as "osc". Now it will be
something like "/dcc/osc@0".

Signed-off-by: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-06-20 00:02:18 -07:00
Paul Walmsley
1c472d8e82 clk: tegra: T114: add DFLL DVCO reset control
Add DFLL DVCO reset line control functions to the CAR IP block driver.

The DVCO present in the DFLL IP block has a separate reset line,
exposed via the CAR IP block.  This reset line is asserted upon SoC
reset.  Unless something (such as the DFLL driver) deasserts this
line, the DVCO will not oscillate, although reads and writes to the
DFLL IP block will complete.

Thanks to Aleksandr Frid <afrid@nvidia.com> for identifying this and
saving hours of debugging time.

Signed-off-by: Paul Walmsley <pwalmsley@nvidia.com>
Cc: Aleksandr Frid <afrid@nvidia.com>
Cc: Peter De Schrijver <pdeschrijver@nvidia.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-06-18 11:28:51 -07:00
Paul Walmsley
9e60121fd1 clk: tegra: T114: add DFLL source clocks
Add the input clocks needed by the DFLL IP blocks.  Initialize them to
51MHz (as required by the DFLL GFD) and to use the PLL_P clock source.

This patch is a collaboration with Peter De Schrijver
<pdeschrijver@nvidia.com>.

Thanks to Laxman Dewangan <ldewangan@nvidia.com> for identifying the
requirement to keep the DFLL clocks enabled to resolve PWR_I2C timeout
issues.

Signed-off-by: Paul Walmsley <pwalmsley@nvidia.com>
Cc: Peter De Schrijver <pdeschrijver@nvidia.com>
Reviewed-by: Andrew Chew <achew@nvidia.com>
Cc: Matthew Longnecker <mlongnecker@nvidia.com>
Cc: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-06-18 11:28:48 -07:00
Paul Walmsley
25c9ded6ed clk: tegra: T114: add FCPU clock shaper programming, needed by the DFLL
Add clock functions to initialize, enable, and disable the FCPU clock
shapers, based on the FCPU voltage rail state.  These will be used by
the DFLL clocksource driver code.

This version of the patch contains a fix for a problem noticed by Andrew
Chew <achew@nvidia.com>, where some of the FINETRIM_R bitfields were
incorrectly defined.

Based on code originally written by Aleksandr Frid <afrid@nvidia.com>.

Signed-off-by: Paul Walmsley <pwalmsley@nvidia.com>
Cc: Andrew Chew <achew@nvidia.com>
Reviewed-by: Andrew Chew <achew@nvidia.com>
Cc: Matthew Longnecker <mlongnecker@nvidia.com>
Cc: Aleksandr Frid <afrid@nvidia.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-06-18 11:28:36 -07:00
Haojian Zhuang
045779942c clk: gate: add CLK_GATE_HIWORD_MASK
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>
2013-06-15 20:23:53 -07:00
Haojian Zhuang
d57dfe7508 clk: divider: add CLK_DIVIDER_HIWORD_MASK flag
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>
2013-06-15 20:23:49 -07:00
Haojian Zhuang
ba492e9007 clk: mux: add CLK_MUX_HIWORD_MASK
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>
2013-06-15 20:23:36 -07:00
Soren Brinkmann
f3aab5d614 clk: Always notify whole subtree when reparenting
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>
2013-06-15 14:34:41 -07:00
Peter De Schrijver
34e452a152 clk: honor CLK_GET_RATE_NOCACHE in clk_set_rate
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>
2013-06-11 18:04:08 -07:00
Peter De Schrijver
670decdd95 clk: use clk_get_rate() for debugfs
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>
2013-06-11 18:03:54 -07:00
Peter De Schrijver
408a24f822 clk: tegra: Use override bits when needed
PLLM has override bits in the PMC. Use those when PLLM_OVERRIDE_ENABLE
is set.

Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-06-11 18:00:32 -07:00
Peter De Schrijver
c09e32bb67 clk: tegra: override bits for Tegra30 PLLM
Define override bits for Tegra30 PLLM.

Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-06-11 18:00:23 -07:00
Peter De Schrijver
d53442e94d clk: tegra: override bits for Tegra114 PLLM
Define override bits for Tegra114 PLLM.

Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
[mturquette@linaro.org: fixed up trivial merge conflict]
2013-06-11 17:59:32 -07:00
Peter De Schrijver
7b781c72c9 clk: tegra: Add fields for override bits
PLLM can have override bits in the PMC. Describe those in the PLL parameters.

Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-06-11 17:59:17 -07:00
Peter De Schrijver
29b09447b6 clk: tegra: fix sclk_parents
Use the correct parents for sclk according to the TRM.

Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-06-11 17:50:05 -07:00
Peter De Schrijver
35d287a9f7 clk: tegra: fix pllre initilization
The PLLRE flags weren't set correctly. Fixed in this patch.

Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-06-11 17:43:51 -07:00
Peter De Schrijver
fd428ad87b clk: tegra: PLL m,n,p init for Tegra114
Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-06-11 17:39:24 -07:00
Peter De Schrijver
aa6fefde62 clk: tegra: allow PLL m,n,p init from SoC files
The m,n,p fields don't have the same bit offset and width across all PLLs.
This patch allows SoC specific files to indicate the offset and width.

Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-06-11 17:38:39 -07:00
Peter De Schrijver
c388eee21a clk: tegra: pllp_out2 divider is int only
The pllp_out2 should be integer only, the fractional bit should always be 0.

Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-06-11 17:07:39 -07:00
Peter De Schrijver
053b525f6f clk: tegra: pllc and pllxc should use pdiv_map
The pllc and pllxc code weren't always using the correct pdiv_map to
map between the post divider value and the hw p field. This could result
in illegal values being programmed in the hw.

Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-06-11 16:15:22 -07:00
Shawn Guo
081c9025f4 clk: divider: do not propagate rate change request when unnecessary
If the current rate of parent clock is sufficient to provide child a
requested rate with a proper divider setting, the rate change request
should not be propagated.  Instead, changing the divider setting is good
enough to get child clock run at the requested rate.

On an imx6q clock configuration illustrated below,

  ahb --> ipg --> ipg_per
  132M    66M     66M

calling clk_set_rate(ipg_per, 22M) with the current
clk_divider_bestdiv() implementation will result in the rate change up
to ahb level like the following, because of the unnecessary/incorrect
rate change propagation.

  ahb --> ipg --> ipg_per
  66M     22M     22M

Fix the problem by trying to see if the requested rate can be achieved
by simply changing the divider value, and in that case return the
divider immediately from function clk_divider_bestdiv() as the best
one, so that all those unnecessary rate change propagation can be saved.

Reported-by: Anson Huang <b20788@freescale.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-06-10 15:20:48 -07:00
Philippe Begnic
a6a3ec7b51 clk: ux500: Clocks definition for u8540
First clocks definition version of PRCMU and PRCC clocks for u8540 platform

Signed-off-by: Philippe Begnic <philippe.begnic@st.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-06-06 18:17:25 -07:00
Philippe Begnic
1237e598a9 clk: ux500: Pass clock base adresses in initcall for u8540 and u9540
Align on u8500 version, pass clock base address in clk_init functions
for u8540 and u9540.

Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Philippe Begnic <philippe.begnic@st.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-06-06 18:16:04 -07:00
Mikko Perttunen
88235988d7 clk: tegra114: Fix msenc clock register
The msenc clock's register was set to the usb3 clock's register.

Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Acked-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-06-04 23:52:53 -07:00
Prashant Gaikwad
061cec925f clk: tegra: Use common of_clk_init function
Use common of_clk_init() function for clocks initialization.

Signed-off-by: Prashant Gaikwad <pgaikwad@nvidia.com>
Reviewed-by: Thierry Reding <thierry.reding@gmail.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-05-31 12:57:25 -07:00
Alexandre Courbot
9139227d4c clk: tegra114: correctly output clk_32k
Tegra has a blink timer register that allows to modulate the
clk_32k clock before outputting it. Since clk_32k is presented to the
kernel as a fixed clock, make sure this register does not tamper with
the clock frequency and that clk_32k is outputted as-is, similarly to
what is done on t20 and t30.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-05-31 12:24:36 -07:00
Prashant Gaikwad
995968e40e clk: tegra: fix clk_out parents list
Number of parents for clk_out_2 and clk_out_3 was incorrectly set
to clk_out1_parents. Even though it did not break anything since the
size was same better to fix.

Signed-off-by: Prashant Gaikwad <pgaikwad@nvidia.com>
Reviewed-by: Thierry Reding <thierry.reding@gmail.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-05-31 12:22:00 -07:00
Daniel Tang
7d1818fa66 clk: Add TI-Nspire clock drivers
This patch adds a basic clock driver for the TI-Nspire calculator
series.

Changes from v1:
* Removed filename in header comment
* Removed unnecessary #undef EXTRACT statement

Signed-off-by: Daniel Tang <dt.tangr@gmail.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
[mturquette@linaro.org: fixed $SUBJECT and changelog max width]
2013-05-31 12:07:45 -07:00
Jingoo Han
c0431037b4 clk: use platform_{get,set}_drvdata()
Use the wrapper functions for getting and setting the driver data using
platform_device instead of using dev_{get,set}_drvdata() with &pdev->dev,
so we can directly pass a struct platform_device.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-05-30 18:19:34 -07:00
Tang Yuantian
4bcccf193d clk: mpc85xx: Update the compatible string
The compatible string of clock is changed from *-2 to *-2.0
on chassis 2. So updated it accordingly.

Signed-off-by: Tang Yuantian <Yuantian.Tang@freescale.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
[mturquette@linaro.org: improved $SUBJECT line]
2013-05-30 11:55:35 -07:00
Giacomo A. Catenazzi
61fd58dc57 clk: sunxi: "cpu_data" is defined in header files of some architectures
In some architectures, the #define cpu_data is not a "macro-function",
so the compiler will substitute the identifier with probably something
wrong.

Signed-off-by: Giacomo A. Catenazzi <cate@cateee.net>
Signed-off-by: Emilio López <emilio@elopez.com.ar>
[emilio@elopez.com.ar: use cpu_mux_data instead of this_cpu_data]
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-05-29 15:48:23 -07:00
Tushar Behera
0e56523fd7 clk: exynos5250: Add sclk_mpll to the parent list of mout_cpu clock
'mout_mpll' is added the list of parent clocks for 'mout_cpu'.
'mout_mpll' is an alias to the clock 'sclk_mpll'. Hence 'sclk_mpll'
should be added to the list of parent clocks.

This results in an error when cpufreq driver for EXYNOS5250 tries to
set 'mout_mpll' as a parent for 'mout_cpu'.

clk_set_parent: clk sclk_mpll can not be parent of clk mout_cpu

Signed-off-by: Tushar Behera <tushar.behera@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-05-29 15:39:28 -07:00
Tushar Behera
37351fd562 clk: exynos5250: Update cpufreq related clocks for EXYNOS5250
cpufreq driver for EXYNOS5250 is not a platform driver, hence we cannot
currently pass the clock names through a device tree node. Instead, we
need to make them available through a global alias.

cpufreq driver for EXYNOS5250 requires four clocks - 'armclk',
'mout_cpu', 'mout_mpll' and 'mout_apll'.

'armclk' has already been defined with an alias, 'mout_cpu', 'mout_mpll'
and 'mout_apll' are now defined with an alias.

Signed-off-by: Tushar Behera <tushar.behera@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-05-29 15:39:17 -07:00
Tony Prisk
65f2c58f0f clk: vt8500: Remove unnecessary divisor adjustment in vtwm_dclk_set_rate()
The divisor adjustment code to ensure that a divisor is not rounded down,
thereby giving a rate higher than requested, is unnecessary and in some
instances results in the actual rate being much lower than requested due to
rounding errors.

The test is already performed in vtwm_dclk_round_rate(), which is always
called when clk_set_rate is called. Due to rounding errors in the line:
divisor = parent_rate / rate (clk-vt8500.c:160) we will sometimes end up
adjusting the divisor twice - first in round_rate and then again in set_rate.

This patch removes the test/adjustment in vtwm_dclk_set_rate.

Signed-off-by: Tony Prisk <linux@prisktech.co.nz>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-05-29 14:47:17 -07:00
Tony Prisk
518d4709f1 clk: vt8500: Add support for clocks on the WM8850 SoCs
The WM8850 has a different PLL clock to the previous versions. This
patch adds support for the WM8850-style PLL clocks.

Signed-off-by: Tony Prisk <linux@prisktech.co.nz>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-05-29 14:47:05 -07:00
Saravana Kannan
d41d580587 clk: Disable unused clocks after deferred probing is done
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>
2013-05-29 00:52:20 -07:00
Axel Lin
bcc7fd20e2 clk: wm831x: Fix wm831x_clkout_get_parent
Current code looks strange because calling wm831x_clkout_set_parent() with 0 as
parent parameter, wm831x_clkout_get_parent() will return 1.

According to the datasheet:
R16528 (4090h) Clock Control1
        BIT 0: CLKOUT output source select
                0 = FLL output
                1 = 32.768kHz oscillator

Thus fix the entry order in wm831x_clkout_parents[] to make it has
the same meaning as the datasheet and make the return value
of wm831x_clkout_get_parent() consistent with the parent pass to
wm831x_clkout_set_parent().

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-05-28 23:50:52 -07:00
Axel Lin
6f8b314583 clk: wm831x: Fix update wrong register for enable/disable FLL
According to the datasheet, FLL Enable is controlled by
R16530 (4092h) FLL Control1
        BIT 0: FLL Enable
                0 = Disable
                1 = Enable

Thus the code should update WM831X_FLL_CONTROL_1 register rather than
WM831X_FLL_CONTROL_2 register.

Also fixes a trivial typo in dev_crit message.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-05-28 23:50:31 -07:00
Sebastian Hesselbarth
4564dbdadc clk: si5351: Allow to build without CONFIG_OF
With of_clk_provider stubs for CONFIG_OF not set, we can now also enable
clk-si5351 on those architectures.

Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-05-28 22:53:22 -07:00
Saravana Kannan
f8aa0bd5c9 clk: Fix race condition between clk_set_parent and clk_enable()
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]
2013-05-28 22:50:32 -07:00
Jean-Francois Moine
9807362bfe clk: si5351: declare all device IDs for module loading
When the si5351 driver is a kernel module, it is loaded into memory
from its i2c device IDs, but not from its DT compatible properties.

This patch declares the i2c device IDs of all chip variants.

Signed-off-by: Jean-Francois Moine <moinejf@free.fr>
Acked-by: Jason Cooper <jason@lakedaemon.net>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-05-28 22:50:32 -07:00
Maxime Ripard
4f985b4c80 clk: sun5i: Add compatibles for Allwinner A13
The A13 has a lot less clocks than the one found in the Allwinner A10.
Add these stripped down clocks to the clock driver and in the
documentation.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Emilio López <emilio@elopez.com.ar>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-05-28 22:50:31 -07:00
Fabio Baltieri
20faa59e0f clk: ux500: abx500-clk: rename ux500 audio codec aliases
Change soc-audio related clk_register_clkdev() device names to reflect
the ones actually used in current snd-soc-mop500 and ab8500-codec
drivers.

Cc: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Fabio Baltieri <fabio.baltieri@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-05-28 22:50:31 -07:00
Sebastian Hesselbarth
1a0483d2a4 clk: si5351: Allow user to define disabled state for every clock output
This patch adds platform data and DT bindings to allow to overwrite
the stored disabled state for each clock output.

Signed-off-by: Marek Belisko <marek.belisko@streamunlimited.com>
Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-05-28 22:50:31 -07:00
Tang Yuantian
555eae9735 clk: add PowerPC corenet clock driver support
This adds the clock driver for Freescale PowerPC corenet
series SoCs using common clock infrastructure.

Signed-off-by: Tang Yuantian <Yuantian.Tang@freescale.com>
Signed-off-by: Li Yang <leoli@freescale.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-05-28 22:50:31 -07:00
Linus Torvalds
27a24cfa04 Merge branch 'fixes' of git://git.infradead.org/users/vkoul/slave-dma
Pull slave-dma fixes from Vinod Koul:
 "We have two patches from Andy & Rafael fixing the Lynxpoint dma"

* 'fixes' of git://git.infradead.org/users/vkoul/slave-dma:
  ACPI / LPSS: register clock device for Lynxpoint DMA properly
  dma: acpi-dma: parse CSRT to extract additional resources
2013-05-25 20:30:31 -07:00
Lucas Stach
6ec3240047 clk: tegra: add ac97 controller clock
AC97 controller clock is hardwired to pll_a_out0.

Signed-off-by: Lucas Stach <dev@lynxeye.de>
Acked-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Reviewed-by: Prashant Gaikwad <pgaikwad@nvidia.com>
Acked-by: Mike Turquette <mturquette@linaro.org>
Tested-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Olof Johansson <olof@lixom.net>
2013-05-20 23:24:34 -07:00