linux-toradex.git/drivers/cpufreq/pmac64-cpufreq.c, branch v4.4.14

of: Migrate of_find_node_by_name() users to for_each_node_by_name()

2014-06-26T16:12:24+00:00

There are a bunch of users open coding the for_each_node_by_name() by
calling of_find_node_by_name() directly instead of using the macro. This
is getting in the way of some cleanups, and the possibility of removing
of_find_node_by_name() entirely. Clean it up so that all the users are
consistent.

Signed-off-by: Grant Likely 
Cc: Rob Herring 
Cc: Benjamin Herrenschmidt 
Cc: "Rafael J. Wysocki" 
Cc: Greg Kroah-Hartman 
Cc: Takashi Iwai

cpufreq: create another field .flags in cpufreq_frequency_table

2014-04-07T12:43:50+00:00

Currently cpufreq frequency table has two fields: frequency and driver_data.
driver_data is only for drivers' internal use and cpufreq core shouldn't use
it at all. But with the introduction of BOOST frequencies, this assumption
was broken and we started using it as a flag instead.

There are two problems due to this:
- It is against the description of this field, as driver's data is used by
  the core now.
- if drivers fill it with -3 for any frequency, then those frequencies are
  never considered by cpufreq core as it is exactly same as value of
  CPUFREQ_BOOST_FREQ, i.e. ~2.

The best way to get this fixed is by creating another field flags which
will be used for such flags. This patch does that. Along with that various
drivers need modifications due to the change of struct cpufreq_frequency_table.

Reviewed-by: Gautham R Shenoy 
Signed-off-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki

cpufreq: move freq change notifications to cpufreq core

2013-10-30T23:11:08+00:00

Most of the drivers do following in their ->target_index() routines:

	struct cpufreq_freqs freqs;
	freqs.old = old freq...
	freqs.new = new freq...

	cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);

	/* Change rate here */

	cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);

This is replicated over all cpufreq drivers today and there doesn't exists a
good enough reason why this shouldn't be moved to cpufreq core instead.

There are few special cases though, like exynos5440, which doesn't do everything
on the call to ->target_index() routine and call some kind of bottom halves for
doing this work, work/tasklet/etc..

They may continue doing notification from their own code as flag:
CPUFREQ_ASYNC_NOTIFICATION is already set for them.

All drivers are also modified in this patch to avoid breaking 'git bisect', as
double notification would happen otherwise.

Acked-by: Hans-Christian Egtvedt 
Acked-by: Jesper Nilsson 
Acked-by: Linus Walleij 
Acked-by: Russell King 
Acked-by: Stephen Warren 
Tested-by: Andrew Lunn 
Tested-by: Nicolas Pitre 
Reviewed-by: Lan Tianyu 
Signed-off-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki

cpufreq: Implement light weight ->target_index() routine

2013-10-25T20:42:24+00:00

Currently, the prototype of cpufreq_drivers target routines is:

int target(struct cpufreq_policy *policy, unsigned int target_freq,
		unsigned int relation);

And most of the drivers call cpufreq_frequency_table_target() to get a valid
index of their frequency table which is closest to the target_freq. And they
don't use target_freq and relation after that.

So, it makes sense to just do this work in cpufreq core before calling
cpufreq_frequency_table_target() and simply pass index instead. But this can be
done only with drivers which expose their frequency table with cpufreq core. For
others we need to stick with the old prototype of target() until those drivers
are converted to expose frequency tables.

This patch implements the new light weight prototype for target_index() routine.
It looks like this:

int target_index(struct cpufreq_policy *policy, unsigned int index);

CPUFreq core will call cpufreq_frequency_table_target() before calling this
routine and pass index to it. Because CPUFreq core now requires to call routines
present in freq_table.c CONFIG_CPU_FREQ_TABLE must be enabled all the time.

This also marks target() interface as deprecated. So, that new drivers avoid
using it. And Documentation is updated accordingly.

It also converts existing .target() to newly defined light weight
.target_index() routine for many driver.

Acked-by: Hans-Christian Egtvedt 
Acked-by: Jesper Nilsson 
Acked-by: Linus Walleij 
Acked-by: Russell King 
Acked-by: David S. Miller 
Tested-by: Andrew Lunn 
Signed-off-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki

cpufreq: pmac64: enable cpufreq on iMac G5 (iSight) model

2013-10-16T22:56:56+00:00

Enable cpufreq on iMac G5 (iSight) model. Tested with the 2.1 GHz version.

Signed-off-by: Aaro Koskinen 
Acked-by: Viresh Kumar 
Acked-by: Benjamin Herrenschmidt 
Signed-off-by: Rafael J. Wysocki

cpufreq: pmac64: provide cpufreq transition latency for older G5 models

2013-10-16T22:56:56+00:00

Currently cpufreq ondemand governor cannot used on older G5 models,
because the transition latency is set to CPUFREQ_ETERNAL. Provide a
value based on a measurement on Xserve G5, which happens to be also the
highest allowed latency.

Signed-off-by: Aaro Koskinen 
Acked-by: Benjamin Herrenschmidt 
Signed-off-by: Rafael J. Wysocki

cpufreq: pmac64: speed up frequency switch

2013-10-16T22:56:56+00:00

Some functions on switch path use msleep() which is inaccurate, and
depends on HZ. With HZ=100 msleep(1) takes actually over ten times longer.
Using usleep_range() we get more accurate sleeps.

I measured the "pfunc_slewing_done" polling to take 300us at max (on
2.3GHz dual-processor Xserve G5), so using 500us sleep there should
be fine.

With the patch, g5_switch_freq() duration drops from ~50ms to ~10ms on
Xserve with HZ=100.

Signed-off-by: Aaro Koskinen 
Acked-by: Viresh Kumar 
Acked-by: Benjamin Herrenschmidt 
Signed-off-by: Rafael J. Wysocki

cpufreq: pmac64: use cpufreq_generic_init()

2013-10-15T22:50:34+00:00

Use generic cpufreq_generic_init() routine instead of replicating the same code
here.

Signed-off-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki

cpufreq: pmac: don't initialize part of policy set by core

2013-10-15T22:50:31+00:00

Many common initializations of struct policy are moved to core now and hence
this driver doesn't need to do it. This patch removes such code.

Most recent of those changes is to call ->get() in the core after calling
->init().

Signed-off-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki

cpufreq: pmac: Use generic cpufreq routines

2013-10-15T22:50:26+00:00

Most of the CPUFreq drivers do similar things in .exit() and .verify() routines
and .attr. So its better if we have generic routines for them which can be used
by cpufreq drivers then.

This patch uses these generic routines in the pmac driver.

Signed-off-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki