From: Leonard Crestez <leonard.crestez@nxp.com>
To: Chanwoo Choi <chanwoo@kernel.org>,
Georgi Djakov <georgi.djakov@linaro.org>
Cc: Chanwoo Choi <cw00.choi@samsung.com>,
Rob Herring <robh+dt@kernel.org>,
Alexandre Bailon <abailon@baylibre.com>,
"Rafael J. Wysocki" <rafael@kernel.org>,
Jacky Bai <ping.bai@nxp.com>, Anson Huang <anson.huang@nxp.com>,
Abel Vesa <abel.vesa@nxp.com>,
Krzysztof Kozlowski <krzk@kernel.org>,
MyungJoo Ham <myungjoo.ham@samsung.com>,
Kyungmin Park <kyungmin.park@samsung.com>,
Saravana Kannan <saravanak@google.com>,
Mark Rutland <mark.rutland@arm.com>,
Viresh Kumar <viresh.kumar@linaro.org>,
Shawn Guo <shawnguo@kernel.org>,
Aisheng Dong <aisheng.dong@nxp.com>,
Fabio Estevam <fabio.estevam@nxp.com>,
Stephen Boyd <sboyd@kernel.org>,
Michael Turquette <mturquette@baylibre.com>,
Matthias Kaehlcke <mka@chromium.org>,
Angus Ainslie <angus@akkea.ca>,
Martin Kepplinger <martink@posteo.de>,
Silvano Di Ninno <silvano.dininno@nxp.com>,
"linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org>,
"kernel@pengutronix.de" <kernel@pengutronix.de>,
dl-linux-imx <linux-imx@nxp.com>,
"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH RFC v6 3/9] PM / devfreq: imx: Register interconnect device
Date: Wed, 18 Dec 2019 17:13:24 +0000 [thread overview]
Message-ID: <VI1PR04MB7023B782510853FE0FDDEFEEEE530@VI1PR04MB7023.eurprd04.prod.outlook.com> (raw)
In-Reply-To: CAGTfZH1omr9jqRv9JX+X253YardFx_B26Hm-cT8UNF2J7eC_og@mail.gmail.com
On 18.12.2019 13:06, Chanwoo Choi wrote:
> 2019년 12월 18일 (수) 오후 7:14, Leonard Crestez <leonard.crestez@nxp.com>님이 작성:
>> On 17.12.2019 02:55, Chanwoo Choi wrote:
>>> On 12/17/19 12:00 AM, Leonard Crestez wrote:
>>>> On 13.12.2019 06:22, Chanwoo Choi wrote:
>>>>> On 11/15/19 5:09 AM, Leonard Crestez wrote:
>>>>>> There is no single device which can represent the imx interconnect.
>>>>>> Instead of adding a virtual one just make the main &noc act as the
>>>>>> global interconnect provider.
>>>>>>
>>>>>> The imx interconnect provider driver will scale the NOC and DDRC based
>>>>>> on bandwidth request. More scalable nodes can be added in the future,
>>>>>> for example for audio/display/vpu/gpu NICs.
>>>>>>
>>>>>> Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
>>>>>> ---
>>>>>> drivers/devfreq/imx-devfreq.c | 37 +++++++++++++++++++++++++++++++++++
>>>>>> 1 file changed, 37 insertions(+)
>>>>>>
>>>>>> diff --git a/drivers/devfreq/imx-devfreq.c b/drivers/devfreq/imx-devfreq.c
>>>>>> index 620b344e87aa..585d340c0f6e 100644
>>>>>> --- a/drivers/devfreq/imx-devfreq.c
>>>>>> +++ b/drivers/devfreq/imx-devfreq.c
>>>>>> @@ -15,10 +15,11 @@
>>>>>> struct imx_devfreq {
>>>>>> struct devfreq_dev_profile profile;
>>>>>> struct devfreq *devfreq;
>>>>>> struct clk *clk;
>>>>>> struct devfreq_passive_data passive_data;
>>>>>> + struct platform_device *icc_pdev;
>>>>>> };
>>>>>>
>>>>>> static int imx_devfreq_target(struct device *dev,
>>>>>> unsigned long *freq, u32 flags)
>>>>>> {
>>>>>> @@ -60,11 +61,40 @@ static int imx_devfreq_get_dev_status(struct device *dev,
>>>>>> return 0;
>>>>>> }
>>>>>>
>>>>>> static void imx_devfreq_exit(struct device *dev)
>>>>>> {
>>>>>> + struct imx_devfreq *priv = dev_get_drvdata(dev);
>>>>>> +
>>>>>> dev_pm_opp_of_remove_table(dev);
>>>>>> + platform_device_unregister(priv->icc_pdev);
>>>>>> +}
>>>>>> +
>>>>>> +/* imx_devfreq_init_icc() - register matching icc provider if required */
>>>>>> +static int imx_devfreq_init_icc(struct device *dev)
>>>>>> +{
>>>>>> + struct imx_devfreq *priv = dev_get_drvdata(dev);
>>>>>> + const char *icc_driver_name;
>>>>>> +
>>>>>> + if (!IS_ENABLED(CONFIG_INTERCONNECT_IMX))
>>>>>> + return 0;
>>>>>
>>>>> It is not proper to check the enable state of CONFIG_INTERCONNECT_IMX configuration
>>>>> on device driver. Why don't you add the 'select CONFIG_INTERCONNECT_IMX' on Kconfig?
>>>>
>>>> Because it's optional.
>>>>
>>>> You can disable interconnect support and just tweak frequencies using
>>>> the devfreq sysfs API. But indeed would only really be useful for debugging.
>>>
>>> Even if it's optional, I don't prefer to use 'IS_ENABLED' macro.
>>>
>>> Generally, add or delete the property or value at DT file
>>> to either enable or disable the some feature provided by device driver
>>> instead of checking the configuration.
>>>
>>> If user adds the property/value related to interconnect
>>> and imx-bus.c configuration is enabled, the behavior
>>> related to interconnect on imx-bus.c doesn't work. It make some confusion.
>>
>> Maybe I could print a warning if #interconnect-cells is present but
>> CONFIG_INTERCONNECT_IMX is off?
>
> Actually, user might think that if imx-bus.c is enabled
> , CONFIG_INTERCONNECT_MIX is enabled.
> Because, the dt binding document of imx-bus.c will
> contain the property for interconnect.
>
> If device driver support the various feature,
> the device driver have to enable all configuration
> in order to support the features for user.
>> An explicit select in Kconfig seems like a pointless limitation but in
>> practice it would almost never be useful to build one without the other.
>
> This patch is for the some CONFIG_INTERCONNECT_IMX driver.
> I don't understand why is not meaningful to select CONFIG_INTERCONNECT_IMX
> in Kconfig?
One issue is that the interconnect graph is described per-soc and there
are per-soc config options while imx-bus applies to all. So the "if"
condition is not sufficient either; if the per-soc interconnect driver
is omitted then the platform device will be added but no driver will be
ever be found.
There are ways around this: for example all of imx interconnect could be
built as a single module. But I think it's reasonable for devices to be
partially functional if some config options are missing and heavy config
customization sometimes requires a bit of debugging.
There are various issues when building the current series as "m" but I
can solve them and post a final patch which sets all the relevant
options on "m" in arm64 defconfig. The it will all "just work" out of
the box.
>>> The imx-bus.c have to add the 'select CONFIG_INTERCONNECT_IMX'
>>> and hand over the right which use the interconnect feature or not, to user.
>>>
>>> If there are any requirement to add the additional property
>>> to check whether interconnect feature will be used or not,
>>> you can add the extra property. But, I think that it is enough
>>> to check the '#interconnect-cells'.
>>>
>>> In result, I think that it is right to decide the usage of feature
>>> of device driver by user on Devicetree.
>>>
>>>>
>>>>>> + if (!of_get_property(dev->of_node, "#interconnect-cells", 0))
>>>>>> + return 0;
>>>>>> +
>>>>>> + icc_driver_name = of_device_get_match_data(dev);
>>>>>> + if (!icc_driver_name)
>>>>>> + return 0;
>>>>>> +
>>>>>> + priv->icc_pdev = platform_device_register_data(
>>>>>> + dev, icc_driver_name, 0, NULL, 0);
>>>>>> + if (IS_ERR(priv->icc_pdev)) {
>>>>>> + dev_err(dev, "failed to register icc provider %s: %ld\n",
>>>>>> + icc_driver_name, PTR_ERR(priv->devfreq));
>>>>>> + return PTR_ERR(priv->devfreq);
>>>>>> + }
>>>>>> +
>>>>>> + return 0;
>>>>>> }
>>>>>>
>>>>>> static int imx_devfreq_probe(struct platform_device *pdev)
>>>>>> {
>>>>>> struct device *dev = &pdev->dev;
>>>>>> @@ -120,18 +150,25 @@ static int imx_devfreq_probe(struct platform_device *pdev)
>>>>>> ret = PTR_ERR(priv->devfreq);
>>>>>> dev_err(dev, "failed to add devfreq device: %d\n", ret);
>>>>>> goto err;
>>>>>> }
>>>>>>
>>>>>> + ret = imx_devfreq_init_icc(dev);
>>>>>> + if (ret)
>>>>>> + goto err;
>>>>>> +
>>>>>> return 0;
>>>>>>
>>>>>> err:
>>>>>> dev_pm_opp_of_remove_table(dev);
>>>>>> return ret;
>>>>>> }
>>>>>>
>>>>>> static const struct of_device_id imx_devfreq_of_match[] = {
>>>>>> + { .compatible = "fsl,imx8mq-noc", .data = "imx8mq-interconnect", },
>>>>>> + { .compatible = "fsl,imx8mm-noc", .data = "imx8mm-interconnect", },
>>>>>> + { .compatible = "fsl,imx8mn-noc", .data = "imx8mn-interconnect", },
>>>>>> { .compatible = "fsl,imx8m-noc", },
>>>>>> { .compatible = "fsl,imx8m-nic", },
>>>>>> { /* sentinel */ },
>>>>>> };
>>>>>> MODULE_DEVICE_TABLE(of, imx_devfreq_of_match);
next prev parent reply other threads:[~2019-12-18 17:13 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-14 20:09 [PATCH RFC v6 0/9] interconnect: Add imx support via devfreq Leonard Crestez
2019-11-14 20:09 ` [PATCH RFC v6 1/9] dt-bindings: interconnect: Add bindings for imx8m noc Leonard Crestez
2019-12-16 1:12 ` Chanwoo Choi
2019-12-16 3:25 ` Chanwoo Choi
2019-12-16 15:09 ` Leonard Crestez
2019-12-17 0:15 ` Chanwoo Choi
2019-12-19 14:31 ` Leonard Crestez
2019-12-19 15:55 ` Chanwoo Choi
2019-12-19 19:11 ` Leonard Crestez
2019-11-14 20:09 ` [PATCH RFC v6 2/9] PM / devfreq: Add generic imx bus scaling driver Leonard Crestez
2019-11-20 14:08 ` Angus Ainslie
2019-11-20 15:04 ` Leonard Crestez
2019-11-20 15:29 ` Marco Felsch
2019-11-20 15:41 ` Angus Ainslie
2019-11-20 16:30 ` Leonard Crestez
2019-11-20 16:38 ` Angus Ainslie
2019-11-20 18:02 ` Leonard Crestez
2020-02-04 9:45 ` Martin Kepplinger
2020-02-13 10:53 ` Martin Kepplinger
2019-12-13 1:30 ` Chanwoo Choi
2019-12-13 1:51 ` Chanwoo Choi
2019-12-16 1:06 ` Chanwoo Choi
2019-12-16 14:57 ` Leonard Crestez
2019-12-17 0:41 ` Chanwoo Choi
2019-12-17 21:05 ` Leonard Crestez
2019-12-18 3:15 ` Chanwoo Choi
2019-12-18 10:10 ` Leonard Crestez
2019-12-18 10:46 ` Chanwoo Choi
2019-12-18 17:06 ` Chanwoo Choi
2019-11-14 20:09 ` [PATCH RFC v6 3/9] PM / devfreq: imx: Register interconnect device Leonard Crestez
2019-12-13 4:28 ` Chanwoo Choi
2019-12-16 15:00 ` Leonard Crestez
2019-12-17 1:02 ` Chanwoo Choi
2019-12-18 10:13 ` Leonard Crestez
2019-12-18 11:05 ` Chanwoo Choi
2019-12-18 17:13 ` Leonard Crestez [this message]
2019-12-19 7:07 ` Chanwoo Choi
2019-11-14 20:09 ` [PATCH RFC v6 4/9] interconnect: Add imx core driver Leonard Crestez
2019-12-12 7:29 ` Georgi Djakov
2019-12-19 0:18 ` Leonard Crestez
2019-11-14 20:09 ` [PATCH RFC v6 5/9] interconnect: imx: Add platform driver for imx8mm Leonard Crestez
2019-12-12 7:35 ` Georgi Djakov
2019-12-16 14:35 ` Leonard Crestez
2019-11-14 20:09 ` [PATCH RFC v6 6/9] interconnect: imx: Add platform driver for imx8mq Leonard Crestez
2019-11-14 20:09 ` [PATCH RFC v6 7/9] interconnect: imx: Add platform driver for imx8mn Leonard Crestez
2019-11-14 20:09 ` [PATCH RFC v6 8/9] arm64: dts: imx8m: Add NOC nodes Leonard Crestez
2019-11-14 20:09 ` [PATCH RFC v6 9/9] arm64: dts: imx8m: Add interconnect provider properties Leonard Crestez
2019-12-11 9:53 ` [PATCH RFC v6 0/9] interconnect: Add imx support via devfreq Leonard Crestez
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=VI1PR04MB7023B782510853FE0FDDEFEEEE530@VI1PR04MB7023.eurprd04.prod.outlook.com \
--to=leonard.crestez@nxp.com \
--cc=abailon@baylibre.com \
--cc=abel.vesa@nxp.com \
--cc=aisheng.dong@nxp.com \
--cc=angus@akkea.ca \
--cc=anson.huang@nxp.com \
--cc=chanwoo@kernel.org \
--cc=cw00.choi@samsung.com \
--cc=devicetree@vger.kernel.org \
--cc=fabio.estevam@nxp.com \
--cc=georgi.djakov@linaro.org \
--cc=kernel@pengutronix.de \
--cc=krzk@kernel.org \
--cc=kyungmin.park@samsung.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-imx@nxp.com \
--cc=linux-pm@vger.kernel.org \
--cc=mark.rutland@arm.com \
--cc=martink@posteo.de \
--cc=mka@chromium.org \
--cc=mturquette@baylibre.com \
--cc=myungjoo.ham@samsung.com \
--cc=ping.bai@nxp.com \
--cc=rafael@kernel.org \
--cc=robh+dt@kernel.org \
--cc=saravanak@google.com \
--cc=sboyd@kernel.org \
--cc=shawnguo@kernel.org \
--cc=silvano.dininno@nxp.com \
--cc=viresh.kumar@linaro.org \
/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).