From: Lukasz Luba <l.luba@partner.samsung.com>
To: linux-arm-kernel@lists.infradead.org,
linux-samsung-soc@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-pm@vger.kernel.org, devicetree@vger.kernel.org
Cc: tjakobi@math.uni-bielefeld.de, myungjoo.ham@samsung.com,
kyungmin.park@samsung.com, cw00.choi@samsung.com,
rjw@rjwysocki.net, len.brown@intel.com, pavel@ucw.cz,
gregkh@linuxfoundation.org, keescook@chromium.org,
anton@enomsg.org, ccross@android.com, tony.luck@intel.com,
robh+dt@kernel.org, mark.rutland@arm.com, kgene@kernel.org,
krzk@kernel.org, m.szyprowski@samsung.com,
b.zolnierkie@samsung.com,
Lukasz Luba <l.luba@partner.samsung.com>
Subject: [PATCH v3 2/5] devfreq: add support for suspend/resume of a devfreq device
Date: Wed, 5 Dec 2018 12:05:53 +0100 [thread overview]
Message-ID: <1544007956-28889-3-git-send-email-l.luba@partner.samsung.com> (raw)
In-Reply-To: <1544007956-28889-1-git-send-email-l.luba@partner.samsung.com>
The patch prepares devfreq device for handling suspend/resume
functionality. The new fields will store needed information during this
process. Devfreq framework handles opp-suspend DT entry and there is no
need of modyfications in the drivers code. It uses atomic variables to
make sure no race condition affects the process.
Suggested-by: Tobias Jakobi <tjakobi@math.uni-bielefeld.de>
Suggested-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Lukasz Luba <l.luba@partner.samsung.com>
---
drivers/devfreq/devfreq.c | 47 +++++++++++++++++++++++++++++++++++++++++------
include/linux/devfreq.h | 7 +++++++
2 files changed, 48 insertions(+), 6 deletions(-)
diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index a9fd61b..46517b6 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -316,6 +316,10 @@ static int devfreq_set_target(struct devfreq *devfreq, unsigned long new_freq,
"Couldn't update frequency transition information.\n");
devfreq->previous_freq = new_freq;
+
+ if (devfreq->suspend_freq)
+ devfreq->resume_freq = cur_freq;
+
return err;
}
@@ -667,6 +671,9 @@ struct devfreq *devfreq_add_device(struct device *dev,
}
devfreq->max_freq = devfreq->scaling_max_freq;
+ devfreq->suspend_freq = dev_pm_opp_get_suspend_opp_freq(dev);
+ atomic_set(&devfreq->suspend_count, 0);
+
dev_set_name(&devfreq->dev, "devfreq%d",
atomic_inc_return(&devfreq_no));
err = device_register(&devfreq->dev);
@@ -867,14 +874,28 @@ EXPORT_SYMBOL(devm_devfreq_remove_device);
*/
int devfreq_suspend_device(struct devfreq *devfreq)
{
+ int ret;
+
if (!devfreq)
return -EINVAL;
- if (!devfreq->governor)
+ if (atomic_inc_return(&devfreq->suspend_count) > 1)
return 0;
- return devfreq->governor->event_handler(devfreq,
- DEVFREQ_GOV_SUSPEND, NULL);
+ if (devfreq->governor) {
+ ret = devfreq->governor->event_handler(devfreq,
+ DEVFREQ_GOV_SUSPEND, NULL);
+ if (ret)
+ return ret;
+ }
+
+ if (devfreq->suspend_freq) {
+ ret = devfreq_set_target(devfreq, devfreq->suspend_freq, 0);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
}
EXPORT_SYMBOL(devfreq_suspend_device);
@@ -888,14 +909,28 @@ EXPORT_SYMBOL(devfreq_suspend_device);
*/
int devfreq_resume_device(struct devfreq *devfreq)
{
+ int ret;
+
if (!devfreq)
return -EINVAL;
- if (!devfreq->governor)
+ if (atomic_dec_return(&devfreq->suspend_count) >= 1)
return 0;
- return devfreq->governor->event_handler(devfreq,
- DEVFREQ_GOV_RESUME, NULL);
+ if (devfreq->resume_freq) {
+ ret = devfreq_set_target(devfreq, devfreq->resume_freq, 0);
+ if (ret)
+ return ret;
+ }
+
+ if (devfreq->governor) {
+ ret = devfreq->governor->event_handler(devfreq,
+ DEVFREQ_GOV_RESUME, NULL);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
}
EXPORT_SYMBOL(devfreq_resume_device);
diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h
index e4963b0..d985199 100644
--- a/include/linux/devfreq.h
+++ b/include/linux/devfreq.h
@@ -131,6 +131,9 @@ struct devfreq_dev_profile {
* @scaling_min_freq: Limit minimum frequency requested by OPP interface
* @scaling_max_freq: Limit maximum frequency requested by OPP interface
* @stop_polling: devfreq polling status of a device.
+ * @suspend_freq: frequency of a device set during suspend phase.
+ * @resume_freq: frequency of a device set in resume phase.
+ * @suspend_count: suspend requests counter for a device.
* @total_trans: Number of devfreq transitions
* @trans_table: Statistics of devfreq transitions
* @time_in_state: Statistics of devfreq states
@@ -167,6 +170,10 @@ struct devfreq {
unsigned long scaling_max_freq;
bool stop_polling;
+ unsigned long suspend_freq;
+ unsigned long resume_freq;
+ atomic_t suspend_count;
+
/* information for device frequency transition */
unsigned int total_trans;
unsigned int *trans_table;
--
2.7.4
next prev parent reply other threads:[~2018-12-05 11:06 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20181205110616eucas1p1e0e17b0c6a96c3b6d77516d4b02de8b1@eucas1p1.samsung.com>
2018-12-05 11:05 ` [PATCH v3 0/5] devfreq: handle suspend/resume Lukasz Luba
[not found] ` <CGME20181205110619eucas1p2eb8553c60b4e23b07c76f02b3867827c@eucas1p2.samsung.com>
2018-12-05 11:05 ` [PATCH v3 1/5] devfreq: refactor set_target frequency function Lukasz Luba
[not found] ` <CGME20181205110620eucas1p14de70dc092580b684a0304b5ce771605@eucas1p1.samsung.com>
2018-12-05 11:05 ` Lukasz Luba [this message]
2018-12-06 1:17 ` [PATCH v3 2/5] devfreq: add support for suspend/resume of a devfreq device Chanwoo Choi
2018-12-06 10:13 ` Lukasz Luba
[not found] ` <CGME20181205110620eucas1p14de70dc092580b684a0304b5ce771605@epcms1p1>
2018-12-11 1:43 ` MyungJoo Ham
2018-12-11 8:26 ` Lukasz Luba
[not found] ` <CGME20181205110622eucas1p23d788afd54ad34c0a2663efac8734648@eucas1p2.samsung.com>
2018-12-05 11:05 ` [PATCH v3 3/5] devfreq: add devfreq_suspend/resume() functions Lukasz Luba
2018-12-06 1:30 ` Chanwoo Choi
[not found] ` <CGME20181205110622eucas1p23d788afd54ad34c0a2663efac8734648@epcms1p3>
2018-12-11 2:45 ` MyungJoo Ham
[not found] ` <CGME20181205110623eucas1p120f9d8b38822bf856a5b7d427d00e49f@eucas1p1.samsung.com>
2018-12-05 11:05 ` [PATCH v3 4/5] drivers: power: suspend: call devfreq suspend/resume Lukasz Luba
2018-12-13 14:35 ` Lukasz Luba
[not found] ` <CGME20181205110623eucas1p120f9d8b38822bf856a5b7d427d00e49f@epcms1p7>
2018-12-21 0:33 ` MyungJoo Ham
2019-01-02 15:08 ` Lukasz Luba
2019-01-03 10:08 ` Rafael J. Wysocki
[not found] ` <CGME20181205110625eucas1p10c7b3137fb77ae51a211c4f040c4eb6f@eucas1p1.samsung.com>
2018-12-05 11:05 ` [PATCH v3 5/5] arm: dts: exynos4: opp-suspend in DMC and leftbus Lukasz Luba
2018-12-05 11:12 ` Krzysztof Kozlowski
2018-12-05 11:45 ` Lukasz Luba
[not found] ` <CGME20181205110619eucas1p2eb8553c60b4e23b07c76f02b3867827c@epcms1p7>
2018-12-11 2:08 ` [PATCH v3 1/5] devfreq: refactor set_target frequency function MyungJoo Ham
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1544007956-28889-3-git-send-email-l.luba@partner.samsung.com \
--to=l.luba@partner.samsung.com \
--cc=anton@enomsg.org \
--cc=b.zolnierkie@samsung.com \
--cc=ccross@android.com \
--cc=cw00.choi@samsung.com \
--cc=devicetree@vger.kernel.org \
--cc=gregkh@linuxfoundation.org \
--cc=keescook@chromium.org \
--cc=kgene@kernel.org \
--cc=krzk@kernel.org \
--cc=kyungmin.park@samsung.com \
--cc=len.brown@intel.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pm@vger.kernel.org \
--cc=linux-samsung-soc@vger.kernel.org \
--cc=m.szyprowski@samsung.com \
--cc=mark.rutland@arm.com \
--cc=myungjoo.ham@samsung.com \
--cc=pavel@ucw.cz \
--cc=rjw@rjwysocki.net \
--cc=robh+dt@kernel.org \
--cc=tjakobi@math.uni-bielefeld.de \
--cc=tony.luck@intel.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).