[PATCH v5 0/4] cpufreq-dt: add suspend frequency support

[PATCH v5 0/4] cpufreq-dt: add suspend frequency support

[Bartlomiej Zolnierkiewicz]

Hi,

This patch series adds suspend frequency support (using opp-v2
bindings and suspend-opp functionality) to cpufreq-dt driver and
then adds suspend opp for Exynos4412 based boards.

This patch series fixes suspend/resume support on Exynos4412
based Trats2 board and reboot hang on Exynos4412 based Odroid
U3 board.

Changes since v4:
- removed superfluous CONFIG_PM ifdefs
- added Acked-by tag from Krzysztof to patch #4
- added Acked-by tag from Viresh to patches #1-3

Changes since v3:
- fixed dev_pm_opp_get_suspend_opp() locking
- shortened variable name in dev_pm_opp_get_suspend_opp()
- adjusted cpufreq_generic_suspend() to work with cpufreq-dt
- removed no longer needed cpufreq_dt_suspend()
- added Acked-by tag from Viresh to patch #4

Changes since v2:
- rewrote to use suspend-opp functionality

Changes since v1:
- removed superfluous ";"

Depends on:
- next-20150902 branch of linux-next kernel tree

Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics


Bartlomiej Zolnierkiewicz (4):
  PM / OPP: add dev_pm_opp_get_suspend_opp() helper
  cpufreq: allow cpufreq_generic_suspend() to work without suspend
    frequency
  cpufreq-dt: add suspend frequency support
  ARM: dts: add suspend opp to exynos4412

 arch/arm/boot/dts/exynos4412.dtsi |  1 +
 drivers/base/power/opp.c          | 30 ++++++++++++++++++++++++++++++
 drivers/cpufreq/cpufreq-dt.c      |  9 +++++++++
 drivers/cpufreq/cpufreq.c         |  4 ++--
 include/linux/pm_opp.h            |  6 ++++++
 5 files changed, 48 insertions(+), 2 deletions(-)

-- 
1.9.1

[PATCH v5 1/4] PM / OPP: add dev_pm_opp_get_suspend_opp() helper

[Bartlomiej Zolnierkiewicz]

Add dev_pm_opp_get_suspend_opp() helper to obtain suspend opp.

Cc: Thomas Abraham <thomas.ab@samsung.com>
Cc: Javier Martinez Canillas <javier@osg.samsung.com>
Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Tobias Jakobi <tjakobi@math.uni-bielefeld.de>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
---
 drivers/base/power/opp.c | 30 ++++++++++++++++++++++++++++++
 include/linux/pm_opp.h   |  6 ++++++
 2 files changed, 36 insertions(+)

diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c
index eb25449..3d948ea 100644
--- a/drivers/base/power/opp.c
+++ b/drivers/base/power/opp.c
@@ -341,6 +341,36 @@ unsigned long dev_pm_opp_get_max_clock_latency(struct device *dev)
 EXPORT_SYMBOL_GPL(dev_pm_opp_get_max_clock_latency);
 
 /**
+ * dev_pm_opp_get_suspend_opp() - Get suspend opp
+ * @dev:	device for which we do this operation
+ *
+ * Return: This function returns pointer to the suspend opp if it is
+ * defined, otherwise it returns NULL.
+ *
+ * Locking: This function must be called under rcu_read_lock(). opp is a rcu
+ * protected pointer. The reason for the same is that the opp pointer which is
+ * returned will remain valid for use with opp_get_{voltage, freq} only while
+ * under the locked area. The pointer returned must be used prior to unlocking
+ * with rcu_read_unlock() to maintain the integrity of the pointer.
+ */
+struct dev_pm_opp *dev_pm_opp_get_suspend_opp(struct device *dev)
+{
+	struct device_opp *dev_opp;
+	struct dev_pm_opp *opp;
+
+	opp_rcu_lockdep_assert();
+
+	dev_opp = _find_device_opp(dev);
+	if (IS_ERR(dev_opp))
+		opp = NULL;
+	else
+		opp = dev_opp->suspend_opp;
+
+	return opp;
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_get_suspend_opp);
+
+/**
  * dev_pm_opp_get_opp_count() - Get number of opps available in the opp list
  * @dev:	device for which we do this operation
  *
diff --git a/include/linux/pm_opp.h b/include/linux/pm_opp.h
index cab7ba5..e817722 100644
--- a/include/linux/pm_opp.h
+++ b/include/linux/pm_opp.h
@@ -34,6 +34,7 @@ bool dev_pm_opp_is_turbo(struct dev_pm_opp *opp);
 
 int dev_pm_opp_get_opp_count(struct device *dev);
 unsigned long dev_pm_opp_get_max_clock_latency(struct device *dev);
+struct dev_pm_opp *dev_pm_opp_get_suspend_opp(struct device *dev);
 
 struct dev_pm_opp *dev_pm_opp_find_freq_exact(struct device *dev,
 					      unsigned long freq,
@@ -80,6 +81,11 @@ static inline unsigned long dev_pm_opp_get_max_clock_latency(struct device *dev)
 	return 0;
 }
 
+static inline struct dev_pm_opp *dev_pm_opp_get_suspend_opp(struct device *dev)
+{
+	return NULL;
+}
+
 static inline struct dev_pm_opp *dev_pm_opp_find_freq_exact(struct device *dev,
 					unsigned long freq, bool available)
 {
-- 
1.9.1

[PATCH v5 2/4] cpufreq: allow cpufreq_generic_suspend() to work without suspend frequency

[Bartlomiej Zolnierkiewicz]

Some cpufreq drivers may set suspend frequency only for
selected setups but still would like to use the generic
suspend handler.  Thus don't treat !policy->suspend_freq
condition as an incorrect one.

Cc: Thomas Abraham <thomas.ab@samsung.com>
Cc: Javier Martinez Canillas <javier@osg.samsung.com>
Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Tobias Jakobi <tjakobi@math.uni-bielefeld.de>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
---
 drivers/cpufreq/cpufreq.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index b3d9368..a634fcb 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1626,8 +1626,8 @@ int cpufreq_generic_suspend(struct cpufreq_policy *policy)
 	int ret;
 
 	if (!policy->suspend_freq) {
-		pr_err("%s: suspend_freq can't be zero\n", __func__);
-		return -EINVAL;
+		pr_debug("%s: suspend_freq not defined\n", __func__);
+		return 0;
 	}
 
 	pr_debug("%s: Setting suspend-freq: %u\n", __func__,
-- 
1.9.1

[PATCH v5 3/4] cpufreq-dt: add suspend frequency support

[Bartlomiej Zolnierkiewicz]

Add suspend frequency support and if needed set it to
the frequency obtained from the suspend opp (can be defined
using opp-v2 bindings and is optional).

Cc: Thomas Abraham <thomas.ab@samsung.com>
Cc: Javier Martinez Canillas <javier@osg.samsung.com>
Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Tobias Jakobi <tjakobi@math.uni-bielefeld.de>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
---
 drivers/cpufreq/cpufreq-dt.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/cpufreq/cpufreq-dt.c b/drivers/cpufreq/cpufreq-dt.c
index c3583cd..9b5e7c9 100644
--- a/drivers/cpufreq/cpufreq-dt.c
+++ b/drivers/cpufreq/cpufreq-dt.c
@@ -196,6 +196,7 @@ static int cpufreq_init(struct cpufreq_policy *policy)
 	struct device *cpu_dev;
 	struct regulator *cpu_reg;
 	struct clk *cpu_clk;
+	struct dev_pm_opp *suspend_opp;
 	unsigned long min_uV = ~0, max_uV = 0;
 	unsigned int transition_latency;
 	bool need_update = false;
@@ -329,6 +330,13 @@ static int cpufreq_init(struct cpufreq_policy *policy)
 	policy->driver_data = priv;
 
 	policy->clk = cpu_clk;
+
+	rcu_read_lock();
+	suspend_opp = dev_pm_opp_get_suspend_opp(cpu_dev);
+	if (suspend_opp)
+		policy->suspend_freq = dev_pm_opp_get_freq(suspend_opp) / 1000;
+	rcu_read_unlock();
+
 	ret = cpufreq_table_validate_and_show(policy, freq_table);
 	if (ret) {
 		dev_err(cpu_dev, "%s: invalid frequency table: %d\n", __func__,
@@ -419,6 +427,7 @@ static struct cpufreq_driver dt_cpufreq_driver = {
 	.ready = cpufreq_ready,
 	.name = "cpufreq-dt",
 	.attr = cpufreq_dt_attr,
+	.suspend = cpufreq_generic_suspend,
 };
 
 static int dt_cpufreq_probe(struct platform_device *pdev)
-- 
1.9.1

[PATCH v5 4/4] ARM: dts: add suspend opp to exynos4412

[Bartlomiej Zolnierkiewicz]

Mark 800MHz OPP as a suspend opp for Exynos4412 based
boards so effectively cpufreq-dt driver behavior w.r.t.
suspend frequency matches what the old exynos-cpufreq
driver has been doing.

This patch fixes suspend/resume support on Exynos4412 based
Trats2 board and reboot hang on Exynos4412 based Odroid U3
board.

Cc: Thomas Abraham <thomas.ab@samsung.com>
Cc: Javier Martinez Canillas <javier@osg.samsung.com>
Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Tobias Jakobi <tjakobi@math.uni-bielefeld.de>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
---
 arch/arm/boot/dts/exynos4412.dtsi | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/boot/dts/exynos4412.dtsi b/arch/arm/boot/dts/exynos4412.dtsi
index ca0e3c1..294cfe4 100644
--- a/arch/arm/boot/dts/exynos4412.dtsi
+++ b/arch/arm/boot/dts/exynos4412.dtsi
@@ -98,6 +98,7 @@
 			opp-hz = /bits/ 64 <800000000>;
 			opp-microvolt = <1000000>;
 			clock-latency-ns = <200000>;
+			opp-suspend;
 		};
 		opp07 {
 			opp-hz = /bits/ 64 <900000000>;
-- 
1.9.1

Re: [PATCH v5 0/4] cpufreq-dt: add suspend frequency support

[Rafael J. Wysocki]

On Tuesday, September 08, 2015 06:41:00 PM Bartlomiej Zolnierkiewicz wrote:
> Hi,
> 
> This patch series adds suspend frequency support (using opp-v2
> bindings and suspend-opp functionality) to cpufreq-dt driver and
> then adds suspend opp for Exynos4412 based boards.
> 
> This patch series fixes suspend/resume support on Exynos4412
> based Trats2 board and reboot hang on Exynos4412 based Odroid
> U3 board.
> 
> Changes since v4:
> - removed superfluous CONFIG_PM ifdefs
> - added Acked-by tag from Krzysztof to patch #4
> - added Acked-by tag from Viresh to patches #1-3
> 
> Changes since v3:
> - fixed dev_pm_opp_get_suspend_opp() locking
> - shortened variable name in dev_pm_opp_get_suspend_opp()
> - adjusted cpufreq_generic_suspend() to work with cpufreq-dt
> - removed no longer needed cpufreq_dt_suspend()
> - added Acked-by tag from Viresh to patch #4
> 
> Changes since v2:
> - rewrote to use suspend-opp functionality
> 
> Changes since v1:
> - removed superfluous ";"
> 
> Depends on:
> - next-20150902 branch of linux-next kernel tree

I've queued up [1-3/4] for the next PM pull request.

The [4/4] has to go in separately through the platform tree.

Thanks,
Rafael

Re: [PATCH v5 0/4] cpufreq-dt: add suspend frequency support

[Krzysztof Kozlowski]

On 09.09.2015 10:16, Rafael J. Wysocki wrote:
> On Tuesday, September 08, 2015 06:41:00 PM Bartlomiej Zolnierkiewicz wrote:
>> Hi,
>>
>> This patch series adds suspend frequency support (using opp-v2
>> bindings and suspend-opp functionality) to cpufreq-dt driver and
>> then adds suspend opp for Exynos4412 based boards.
>>
>> This patch series fixes suspend/resume support on Exynos4412
>> based Trats2 board and reboot hang on Exynos4412 based Odroid
>> U3 board.
>>
>> Changes since v4:
>> - removed superfluous CONFIG_PM ifdefs
>> - added Acked-by tag from Krzysztof to patch #4
>> - added Acked-by tag from Viresh to patches #1-3
>>
>> Changes since v3:
>> - fixed dev_pm_opp_get_suspend_opp() locking
>> - shortened variable name in dev_pm_opp_get_suspend_opp()
>> - adjusted cpufreq_generic_suspend() to work with cpufreq-dt
>> - removed no longer needed cpufreq_dt_suspend()
>> - added Acked-by tag from Viresh to patch #4
>>
>> Changes since v2:
>> - rewrote to use suspend-opp functionality
>>
>> Changes since v1:
>> - removed superfluous ";"
>>
>> Depends on:
>> - next-20150902 branch of linux-next kernel tree
> 
> I've queued up [1-3/4] for the next PM pull request.
> 
> The [4/4] has to go in separately through the platform tree.

Dear Rafael,

If you want, the fourth patch can go now through your tree - the late
SoC changes were pulled by Linus. No difference... I can grab it as I
had other DT related fix in queue.

The only important thing is to get entire patchset to 4.3 because it is
a fix for regression introduced in cpufreq for exynos. Do you plan to
send your part in current 4.3 cycle?

Best regards,
Krzysztof

Re: [PATCH v5 0/4] cpufreq-dt: add suspend frequency support

[Viresh Kumar]

On 14-09-15, 16:08, Krzysztof Kozlowski wrote:
> If you want, the fourth patch can go now through your tree - the late
> SoC changes were pulled by Linus. No difference... I can grab it as I
> had other DT related fix in queue.
> 
> The only important thing is to get entire patchset to 4.3 because it is
> a fix for regression introduced in cpufreq for exynos. Do you plan to
> send your part in current 4.3 cycle?

The first 3 patches are already part for 4.3-rc1 and so you can keep
the DT update in your tree now. :)

-- 
viresh

Re: [PATCH v5 0/4] cpufreq-dt: add suspend frequency support

[Krzysztof Kozlowski]

On 14.09.2015 16:17, Viresh Kumar wrote:
> On 14-09-15, 16:08, Krzysztof Kozlowski wrote:
>> If you want, the fourth patch can go now through your tree - the late
>> SoC changes were pulled by Linus. No difference... I can grab it as I
>> had other DT related fix in queue.
>>
>> The only important thing is to get entire patchset to 4.3 because it is
>> a fix for regression introduced in cpufreq for exynos. Do you plan to
>> send your part in current 4.3 cycle?
> 
> The first 3 patches are already part for 4.3-rc1 and so you can keep
> the DT update in your tree now. :)

Damn it, I missed it. It solves everything, the fourth patch will go
through platform tree.

Best regards,
Krzysztof