linux-toradex.git/drivers/cpufreq/cpufreq-cpu0.c, branch v3.11 Linux kernel for Apalis and Colibri modules cpufreq: cpufreq-cpu0: use the exact frequency for clk_set_rate() 2013-06-05T11:51:29+00:00 Guennadi Liakhovetski g.liakhovetski@gmx.de 2013-02-25T17:22:37+00:00 0ca684365547cd5f214b5739568dae3df5d6cec9 clk_set_rate() isn't supposed to accept approximate frequencies, instead a supported frequency should be obtained from clk_round_rate() and then used to set the clock. Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de> Acked-by: Shawn Guo <shawn.guo@linaro.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
clk_set_rate() isn't supposed to accept approximate frequencies, instead
a supported frequency should be obtained from clk_round_rate() and then
used to set the clock.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpufreq: cpufreq-cpu0: Free parent node for error cases 2013-05-12T12:04:16+00:00 Viresh Kumar viresh.kumar@linaro.org 2013-05-03T04:44:25+00:00 5aaa9cc7ab589893efe8e66bf02f7fc2175a1f5b We are freeing parent node in success cases but not in failure cases. Let's do it. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
We are freeing parent node in success cases but not in failure cases.
Let's do it.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpufreq: cpufreq-cpu0: defer probe when regulator is not ready 2013-05-12T12:04:16+00:00 Nishanth Menon nm@ti.com 2013-05-01T13:38:12+00:00 fc31d6f55908759530462998d0464a9f124b1c32 With commit 1e4b545, regulator_get will now return -EPROBE_DEFER when the cpu0-supply node is present, but the regulator is not yet registered. It is possible for this to occur when the regulator registration by itself might be defered due to some dependent interface not yet instantiated. For example: an regulator which uses I2C and GPIO might need both systems available before proceeding, in this case, the regulator might defer it's registration. However, the cpufreq-cpu0 driver assumes that any un-successful return result is equivalent of failure. When the regulator_get returns failure other than -EPROBE_DEFER, it makes sense to assume that supply node is not present and proceed with the assumption that only clock control is necessary in the platform. With this change, we can now handle the following conditions: a) cpu0-supply binding is not present, regulator_get will return appropriate error result, resulting in cpufreq-cpu0 driver controlling just the clock. b) cpu0-supply binding is present, regulator_get returns -EPROBE_DEFER, we retry resulting in cpufreq-cpu0 driver registering later once the regulator is available. c) cpu0-supply binding is present, regulator_get returns -EPROBE_DEFER, however, regulator never registers, we retry until cpufreq-cpu0 driver fails to register pointing at device tree information bug. However, in this case, the fact that cpufreq-cpu0 operates with clock only when the DT binding clearly indicates need of a supply is a bug of it's own. d) cpu0-supply gets an regulator at probe - cpufreq-cpu0 driver controls both the clock and regulator Signed-off-by: Nishanth Menon <nm@ti.com> Acked-by: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
With commit 1e4b545, regulator_get will now return -EPROBE_DEFER
when the cpu0-supply node is present, but the regulator is not yet
registered.

It is possible for this to occur when the regulator registration
by itself might be defered due to some dependent interface not yet
instantiated. For example: an regulator which uses I2C and GPIO might
need both systems available before proceeding, in this case, the
regulator might defer it's registration.

However, the cpufreq-cpu0 driver assumes that any un-successful
return result is equivalent of failure.

When the regulator_get returns failure other than -EPROBE_DEFER, it
makes sense to assume that supply node is not present and proceed
with the assumption that only clock control is necessary in the
platform.

With this change, we can now handle the following conditions:
 a) cpu0-supply binding is not present, regulator_get will return
    appropriate error result, resulting in cpufreq-cpu0 driver
    controlling just the clock.
 b) cpu0-supply binding is present, regulator_get returns
    -EPROBE_DEFER, we retry resulting in cpufreq-cpu0 driver
    registering later once the regulator is available.
 c) cpu0-supply binding is present, regulator_get returns
    -EPROBE_DEFER, however, regulator never registers, we retry until
    cpufreq-cpu0 driver fails to register pointing at device tree
    information bug. However, in this case, the fact that
    cpufreq-cpu0 operates with clock only when the DT binding clearly
    indicates need of a supply is a bug of it's own.
 d) cpu0-supply gets an regulator at probe - cpufreq-cpu0 driver
    controls both the clock and regulator

Signed-off-by: Nishanth Menon <nm@ti.com>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Merge branch 'pm-cpufreq' 2013-04-28T00:10:46+00:00 Rafael J. Wysocki rafael.j.wysocki@intel.com 2013-04-28T00:10:46+00:00 885f925eef411f549f17bc64dd054a3269cf66cd * pm-cpufreq: (57 commits) cpufreq: MAINTAINERS: Add co-maintainer cpufreq: pxa2xx: initialize variables ARM: S5pv210: compiling issue, ARM_S5PV210_CPUFREQ needs CONFIG_CPU_FREQ_TABLE=y cpufreq: cpu0: Put cpu parent node after using it cpufreq: ARM big LITTLE: Adapt to latest cpufreq updates cpufreq: ARM big LITTLE: put DT nodes after using them cpufreq: Don't call __cpufreq_governor() for drivers without target() cpufreq: exynos5440: Protect OPP search calls with RCU lock cpufreq: dbx500: Round to closest available freq cpufreq: Call __cpufreq_governor() with correct policy->cpus mask cpufreq / intel_pstate: Optimize intel_pstate_set_policy cpufreq: OMAP: instantiate omap-cpufreq as a platform_driver arm: exynos: Enable OPP library support for exynos5440 cpufreq: exynos: Remove error return even if no soc is found cpufreq: exynos: Add cpufreq driver for exynos5440 cpufreq: AMD "frequency sensitivity feedback" powersave bias for ondemand governor cpufreq: ondemand: allow custom powersave_bias_target handler to be registered cpufreq: convert cpufreq_driver to using RCU cpufreq: powerpc/platforms/cell: move cpufreq driver to drivers/cpufreq cpufreq: sparc: move cpufreq driver to drivers/cpufreq ... Conflicts: MAINTAINERS (with commit a8e39c3 from pm-cpuidle) drivers/cpufreq/cpufreq_governor.h (with commit beb0ff3) 
* pm-cpufreq: (57 commits)
  cpufreq: MAINTAINERS: Add co-maintainer
  cpufreq: pxa2xx: initialize variables
  ARM: S5pv210: compiling issue, ARM_S5PV210_CPUFREQ needs CONFIG_CPU_FREQ_TABLE=y
  cpufreq: cpu0: Put cpu parent node after using it
  cpufreq: ARM big LITTLE: Adapt to latest cpufreq updates
  cpufreq: ARM big LITTLE: put DT nodes after using them
  cpufreq: Don't call __cpufreq_governor() for drivers without target()
  cpufreq: exynos5440: Protect OPP search calls with RCU lock
  cpufreq: dbx500: Round to closest available freq
  cpufreq: Call __cpufreq_governor() with correct policy->cpus mask
  cpufreq / intel_pstate: Optimize intel_pstate_set_policy
  cpufreq: OMAP: instantiate omap-cpufreq as a platform_driver
  arm: exynos: Enable OPP library support for exynos5440
  cpufreq: exynos: Remove error return even if no soc is found
  cpufreq: exynos: Add cpufreq driver for exynos5440
  cpufreq: AMD "frequency sensitivity feedback" powersave bias for ondemand governor
  cpufreq: ondemand: allow custom powersave_bias_target handler to be registered
  cpufreq: convert cpufreq_driver to using RCU
  cpufreq: powerpc/platforms/cell: move cpufreq driver to drivers/cpufreq
  cpufreq: sparc: move cpufreq driver to drivers/cpufreq
  ...

Conflicts:
	MAINTAINERS (with commit a8e39c3 from pm-cpuidle)
	drivers/cpufreq/cpufreq_governor.h (with commit beb0ff3)
cpufreq: cpu0: Put cpu parent node after using it 2013-04-21T22:53:40+00:00 Viresh Kumar viresh.kumar@linaro.org 2013-04-15T07:09:37+00:00 141b467810b78f2d7a85f4b752b42b92f014629b Parent node must be put after using it to balance its usage count. This was missing in cpufreq-cpu0 driver. Fix it. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
Parent node must be put after using it to balance its usage count. This was
missing in cpufreq-cpu0 driver. Fix it.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpufreq: Notify all policy->cpus in cpufreq_notify_transition() 2013-04-02T13:24:00+00:00 Viresh Kumar viresh.kumar@linaro.org 2013-03-24T06:26:43+00:00 b43a7ffbf33be7e4d3b10b7714ee663ea2c52fe2 policy->cpus contains all online cpus that have single shared clock line. And their frequencies are always updated together. Many SMP system's cpufreq drivers take care of this in individual drivers but the best place for this code is in cpufreq core. This patch modifies cpufreq_notify_transition() to notify frequency change for all cpus in policy->cpus and hence updates all users of this API. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
policy->cpus contains all online cpus that have single shared clock line. And
their frequencies are always updated together.

Many SMP system's cpufreq drivers take care of this in individual drivers but
the best place for this code is in cpufreq core.

This patch modifies cpufreq_notify_transition() to notify frequency change for
all cpus in policy->cpus and hence updates all users of this API.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpufreq: cpufreq-cpu0: Call CPUFREQ_POSTCHANGE notifier for failure cases too 2013-04-02T13:10:48+00:00 Viresh Kumar viresh.kumar@linaro.org 2013-04-01T12:57:44+00:00 fd143b4d6fb763183ef6e46d1ab84a42c59079af Currently we are simply returning from target() if we encounter some error after broadcasting CPUFREQ_PRECHANGE notifier. Which looks to be wrong as others might depend on POSTCHANGE notifier for their functioning. So, better broadcast CPUFREQ_POSTCHANGE notifier for these failure cases too, but with old frequency. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
Currently we are simply returning from target() if we encounter some error after
broadcasting CPUFREQ_PRECHANGE notifier. Which looks to be wrong as others might
depend on POSTCHANGE notifier for their functioning.

So, better broadcast CPUFREQ_POSTCHANGE notifier for these failure cases too,
but with old frequency.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpufreq: cpufreq-cpu0: No need to check cpu number in init() 2013-04-02T13:10:48+00:00 Viresh Kumar viresh.kumar@linaro.org 2013-04-01T12:57:43+00:00 746b3df98b2edc0e0844537a247e820ac6503031 It is not possible for init() to be called for any cpu other than cpu0. During bootup whatever cpu is used to boot system will be assigned as cpu0. And later on policy->cpu can only change if we hotunplug all cpus first and then hotplug them back in different order, which isn't possible (system requires atleast one cpu to be up always :)). Though I can see one situation where policy->cpu can be different then zero. - Hot-unplug cpu 0. - rmmod cpufreq-cpu0 module - insmod it back - hotplug cpu 0 again. Here, policy->cpu would be different. But the driver doesn't have any dependency on cpu0 as such. We don't mind which cpu of a system is policy->cpu and so this check is just not required. Remove it. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
It is not possible for init() to be called for any cpu other than cpu0. During
bootup whatever cpu is used to boot system will be assigned as cpu0. And later
on policy->cpu can only change if we hotunplug all cpus first and then hotplug
them back in different order, which isn't possible (system requires atleast one
cpu to be up always :)).

Though I can see one situation where policy->cpu can be different then zero.
- Hot-unplug cpu 0.
- rmmod cpufreq-cpu0 module
- insmod it back
- hotplug cpu 0 again.

Here, policy->cpu would be different. But the driver doesn't have any dependency
on cpu0 as such. We don't mind which cpu of a system is policy->cpu and so this
check is just not required.

Remove it.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpufreq: check OF node /cpus presence before dereferencing it 2013-04-01T23:36:08+00:00 Paolo Pisati paolo.pisati@canonical.com 2013-03-28T09:24:29+00:00 f5c3ef21db149ba573a3f079df287f3d8b05ee13 Check for the presence of the '/cpus' OF node before dereferencing it blindly: [ 4.181793] Unable to handle kernel NULL pointer dereference at virtual address 0000001c [ 4.181793] pgd = c0004000 [ 4.181823] [0000001c] *pgd=00000000 [ 4.181823] Internal error: Oops: 5 [#1] SMP ARM [ 4.181823] Modules linked in: [ 4.181823] CPU: 1 Tainted: G W (3.8.0-15-generic #25~hbankD) [ 4.181854] PC is at of_get_next_child+0x64/0x70 [ 4.181854] LR is at of_get_next_child+0x24/0x70 [ 4.181854] pc : [<c04fda18>] lr : [<c04fd9d8>] psr: 60000113 [ 4.181854] sp : ed891ec0 ip : ed891ec0 fp : ed891ed4 [ 4.181884] r10: c04dafd0 r9 : c098690c r8 : c0936208 [ 4.181884] r7 : ed890000 r6 : c0a63d00 r5 : 00000000 r4 : 00000000 [ 4.181884] r3 : 00000000 r2 : 00000000 r1 : 00000000 r0 : c0b2acc8 [ 4.181884] Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment kernel [ 4.181884] Control: 10c5387d Table: adcb804a DAC: 00000015 [ 4.181915] Process swapper/0 (pid: 1, stack limit = 0xed890238) [ 4.181915] Stack: (0xed891ec0 to 0xed892000) [ 4.181915] 1ec0: c09b7b70 00000007 ed891efc ed891ed8 c04daff4 c04fd9c0 00000000 c09b7b70 [ 4.181915] 1ee0: 00000007 c0a63d00 ed890000 c0936208 ed891f54 ed891f00 c00088e0 c04dafdc [ 4.181945] 1f00: ed891f54 ed891f10 c006e940 00000000 00000000 00000007 00000007 c08a4914 [ 4.181945] 1f20: 00000000 c07dbd30 c0a63d00 c09b7b70 00000007 c0a63d00 000000bc c0936208 [ 4.181945] 1f40: c098690c c0986914 ed891f94 ed891f58 c0936a40 c00087bc 00000007 00000007 [ 4.181976] 1f60: c0936208 be8bda20 b6eea010 c0a63d00 c064547c 00000000 00000000 00000000 [ 4.181976] 1f80: 00000000 00000000 ed891fac ed891f98 c0645498 c09368c8 00000000 00000000 [ 4.181976] 1fa0: 00000000 ed891fb0 c0014658 c0645488 00000000 00000000 00000000 00000000 [ 4.182006] 1fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 [ 4.182006] 1fe0: 00000000 00000000 00000000 00000000 00000013 00000000 00000000 00000000 [ 4.182037] [<c04fda18>] (of_get_next_child+0x64/0x70) from [<c04daff4>] (cpu0_cpufreq_driver_init+0x24/0x284) [ 4.182067] [<c04daff4>] (cpu0_cpufreq_driver_init+0x24/0x284) from [<c00088e0>] (do_one_initcall+0x130/0x1b0) [ 4.182067] [<c00088e0>] (do_one_initcall+0x130/0x1b0) from [<c0936a40>] (kernel_init_freeable+0x184/0x24c) [ 4.182098] [<c0936a40>] (kernel_init_freeable+0x184/0x24c) from [<c0645498>] (kernel_init+0x1c/0xf4) [ 4.182128] [<c0645498>] (kernel_init+0x1c/0xf4) from [<c0014658>] (ret_from_fork+0x14/0x20) [ 4.182128] Code: f57ff04f e320f004 e89da830 e89da830 (e595001c) [ 4.182128] ---[ end trace 634903a22e8609cb ]--- [ 4.182189] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b [ 4.182189] [ 4.642395] CPU0: stopping [rjw: Changelog] Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
Check for the presence of the '/cpus' OF node before dereferencing it
blindly:

[    4.181793] Unable to handle kernel NULL pointer dereference at virtual address 0000001c
[    4.181793] pgd = c0004000
[    4.181823] [0000001c] *pgd=00000000
[    4.181823] Internal error: Oops: 5 [#1] SMP ARM
[    4.181823] Modules linked in:
[    4.181823] CPU: 1    Tainted: G        W     (3.8.0-15-generic #25~hbankD)
[    4.181854] PC is at of_get_next_child+0x64/0x70
[    4.181854] LR is at of_get_next_child+0x24/0x70
[    4.181854] pc : [<c04fda18>]    lr : [<c04fd9d8>]    psr: 60000113
[    4.181854] sp : ed891ec0  ip : ed891ec0  fp : ed891ed4
[    4.181884] r10: c04dafd0  r9 : c098690c  r8 : c0936208
[    4.181884] r7 : ed890000  r6 : c0a63d00  r5 : 00000000  r4 : 00000000
[    4.181884] r3 : 00000000  r2 : 00000000  r1 : 00000000  r0 : c0b2acc8
[    4.181884] Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment kernel
[    4.181884] Control: 10c5387d  Table: adcb804a  DAC: 00000015
[    4.181915] Process swapper/0 (pid: 1, stack limit = 0xed890238)
[    4.181915] Stack: (0xed891ec0 to 0xed892000)
[    4.181915] 1ec0: c09b7b70 00000007 ed891efc ed891ed8 c04daff4 c04fd9c0 00000000 c09b7b70
[    4.181915] 1ee0: 00000007 c0a63d00 ed890000 c0936208 ed891f54 ed891f00 c00088e0 c04dafdc
[    4.181945] 1f00: ed891f54 ed891f10 c006e940 00000000 00000000 00000007 00000007 c08a4914
[    4.181945] 1f20: 00000000 c07dbd30 c0a63d00 c09b7b70 00000007 c0a63d00 000000bc c0936208
[    4.181945] 1f40: c098690c c0986914 ed891f94 ed891f58 c0936a40 c00087bc 00000007 00000007
[    4.181976] 1f60: c0936208 be8bda20 b6eea010 c0a63d00 c064547c 00000000 00000000 00000000
[    4.181976] 1f80: 00000000 00000000 ed891fac ed891f98 c0645498 c09368c8 00000000 00000000
[    4.181976] 1fa0: 00000000 ed891fb0 c0014658 c0645488 00000000 00000000 00000000 00000000
[    4.182006] 1fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[    4.182006] 1fe0: 00000000 00000000 00000000 00000000 00000013 00000000 00000000 00000000
[    4.182037] [<c04fda18>] (of_get_next_child+0x64/0x70) from [<c04daff4>] (cpu0_cpufreq_driver_init+0x24/0x284)
[    4.182067] [<c04daff4>] (cpu0_cpufreq_driver_init+0x24/0x284) from [<c00088e0>] (do_one_initcall+0x130/0x1b0)
[    4.182067] [<c00088e0>] (do_one_initcall+0x130/0x1b0) from [<c0936a40>] (kernel_init_freeable+0x184/0x24c)
[    4.182098] [<c0936a40>] (kernel_init_freeable+0x184/0x24c) from [<c0645498>] (kernel_init+0x1c/0xf4)
[    4.182128] [<c0645498>] (kernel_init+0x1c/0xf4) from [<c0014658>] (ret_from_fork+0x14/0x20)
[    4.182128] Code: f57ff04f e320f004 e89da830 e89da830 (e595001c)
[    4.182128] ---[ end trace 634903a22e8609cb ]---
[    4.182189] Kernel panic - not syncing: Attempted to kill init!  exitcode=0x0000000b
[    4.182189]
[    4.642395] CPU0: stopping

[rjw: Changelog]
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpufreq: Fix unsigned variable being checked for negative value 2013-03-31T23:11:35+00:00 jhbird.choi@samsung.com jhbird.choi@samsung.com 2013-03-18T08:09:42+00:00 5df6055939f295d723871d9781e73495b131b3d6 clk_round_rate() returns singed value which was assigned to an unsigned variable. So it can't be checked for negative. Signed-off-by: Jonghwan Choi <jhbird.choi@samsung.com> Acked-by: Shawn Guo <shawn.guo@linaro.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
clk_round_rate() returns singed value which was assigned to an unsigned
variable.
So it can't be checked for negative.

Signed-off-by: Jonghwan Choi <jhbird.choi@samsung.com>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>