From: Jingbao Qiu <qiujingbao.dlmu@gmail.com>
To: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: a.zummo@towertech.it, robh+dt@kernel.org,
krzysztof.kozlowski+dt@linaro.org, conor@kernel.org,
conor+dt@kernel.org, chao.wei@sophgo.com,
unicorn_wang@outlook.com, paul.walmsley@sifive.com,
palmer@dabbelt.com, aou@eecs.berkeley.edu,
linux-rtc@vger.kernel.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org, dlan@gentoo.org,
inochiama@outlook.com
Subject: Re: [PATCH v3 3/4] rtc: sophgo: add rtc support for Sophgo CV1800 SoC
Date: Thu, 28 Dec 2023 12:12:25 +0800 [thread overview]
Message-ID: <CAJRtX8Qehq-E+Z9T+fc6r36dtF8ZMNwyqxF3WGOQAmwHZHgLkw@mail.gmail.com> (raw)
In-Reply-To: <202312271350242a208426@mail.local>
On Wed, Dec 27, 2023 at 9:50 PM Alexandre Belloni
<alexandre.belloni@bootlin.com> wrote:
>
> On 27/12/2023 16:03:56+0800, Jingbao Qiu wrote:
> > On Tue, Dec 26, 2023 at 8:37 PM Alexandre Belloni
> > <alexandre.belloni@bootlin.com> wrote:
> > >
> > > Hello,
> > >
> > > please run checkpatch.pl --strict, there are a few issues.
> > >
> > > On 26/12/2023 18:04:30+0800, Jingbao Qiu wrote:
> > > > +struct cv1800_rtc_priv {
> > > > + struct rtc_device *rtc_dev;
> > > > + struct device *dev;
> > > > + struct regmap *rtc_map;
> > > > + struct clk *clk;
> > > > + spinlock_t rtc_lock;
> > >
> > > This lock seems unnecessary, please check
> > >
> >
> > you are right. I will fix it.
> >
> > > > + int irq;
> > > > +};
> > > > +
> > > > +static int cv1800_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
> > > > +{
> > > > + struct cv1800_rtc_priv *info = dev_get_drvdata(dev);
> > > > +
> > > > + if (enabled)
> > > > + regmap_write(info->rtc_map, ALARM_ENABLE, REG_ENABLE_FUN);
> > > > + else
> > > > + regmap_write(info->rtc_map, ALARM_ENABLE, REG_DISABLE_FUN);
> > > > +
> > >
> > > This could be:
> > > regmap_write(info->rtc_map, ALARM_ENABLE, enabled);
> >
> > you are right, i will fix it.
> >
> > >
> > > > + return 0;
> > > > +}
> > > > +
> > > > +static int cv1800_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
> > > > +{
> > > > + struct cv1800_rtc_priv *info = dev_get_drvdata(dev);
> > > > + unsigned long alarm_time;
> > > > +
> > > > + alarm_time = rtc_tm_to_time64(&alrm->time);
> > > > +
> > > > + if (alarm_time > SEC_MAX_VAL)
> > > > + return -EINVAL;
> > >
> > > The core is already checking fr this.
> >
> > Thanks, I will remove it.
> >
> > >
> > > > +
> > > > + regmap_write(info->rtc_map, ALARM_ENABLE, REG_DISABLE_FUN);
> > > > +
> > > > + udelay(DEALY_TIME_PREPARE);
> > >
> > > Why is this needed?
> >
> > This doesn't seem to require waiting, I will check it.
> >
> > >
> > > > +
> > > > + regmap_write(info->rtc_map, ALARM_TIME, alarm_time);
> > > > + regmap_write(info->rtc_map, ALARM_ENABLE, REG_ENABLE_FUN);
> > >
> > > You must follow alrm->enabled instead of unconditionally enabling the
> > > alarm.
> >
> > ok,i will fix it.
> >
> > >
> > > > +
> > > > + return 0;
> > > > +}
> > > > +
> > >
> > >
> > > > +static int cv1800_rtc_32k_coarse_val_calib(struct cv1800_rtc_priv *info)
> > >
> > > Please explain those two calibration functions. I don't think you can
> > > achieve what you want to do.
> >
> > The goal of these two calibration functions is to achieve calibration
> > of RTC time.
> > The code is written according to the data manual.
> >
> > The calibration circuit uses 25MHz crystal clock to sample 32KHz
> > clock. In coarse
> > tune mode, the 25MHz crystal clock samples one 32KHz clock cycle period and
> > report the counting results.
> >
> > the datasheet link:
> > Link: https://github.com/milkv-duo/duo-files/blob/main/duo/datasheet/CV1800B-CV1801B-Preliminary-Datasheet-full-en.pdf
> > page:195
>
>
> I'm really curious as to why this is calibrated using a 25MHz crystal as
> it may be as imprecise as the 32kHz one. I'm asking because we have an
> interface to get calibration done properly so you can use a precise clock
> like GPS, NTP or PTP. This is what you should probably implement
> instead or on top of it.
>
Thanks, I will communicate with the IC designers later.
> > >
> > > > +}
> > > > +
> > > > +static int cv1800_rtc_read_time(struct device *dev, struct rtc_time *tm)
> > > > +{
> > > > + struct cv1800_rtc_priv *info = dev_get_drvdata(dev);
> > > > + unsigned int sec;
> > > > + unsigned int sec_ro_t;
> > > > + unsigned long flag;
> > > > +
> > > > + spin_lock_irqsave(&info->rtc_lock, flag);
> > > > +
> > > > + regmap_read(info->rtc_map, SEC_CNTR_VAL, &sec);
> > > > + regmap_read(info->rtc_map, MACRO_RO_T, &sec_ro_t);
> > > > +
> > > > + if (sec_ro_t > (SET_SEC_CNTR_VAL_UPDATE)) {
> > > > + sec = sec_ro_t;
> > > > + regmap_write(info->rtc_map, SET_SEC_CNTR_VAL, sec);
> > > > + regmap_write(info->rtc_map, SET_SEC_CNTR_TRIG, REG_ENABLE_FUN);
> > >
> > > What does this do?
> >
> > the sec_ro_t be considered to have high accuracy after calibration.
> > So every time read the time, update the RTC time.
>
> So why don't you always use sec_ro_t instead of sec?
> Also, why is this done conditionally on a arbitrary value? As it stands,
> it will happen if the date is after 1995-07-09T16:12:48 for no good
> reason.
> This is awful because the alarm is matching SEC_CNTR_VAL with ALARM_TIME
> so if this means the calibration doesn't affect SEC_CNTR_VAL (which I
> seriously doubt), the alarm will end up being imprecise anyway
>
Thanks, I will communicate with the IC designers later.
> > > > +static int cv1800_rtc_probe(struct platform_device *pdev)
> > > > +{
> > > > + struct cv1800_rtc_priv *rtc;
> > > > + uint32_t ctrl_val;
> > > > + int ret;
> > > > +
> > > > + rtc = devm_kzalloc(&pdev->dev, sizeof(struct cv1800_rtc_priv),
> > > > + GFP_KERNEL);
> > > > + if (!rtc)
> > > > + return -ENOMEM;
> > > > +
> > > > + rtc->dev = &pdev->dev;
> > > > +
> > > > + rtc->rtc_map = syscon_node_to_regmap(rtc->dev->of_node->parent);
> > > > + if (IS_ERR(rtc->rtc_map))
> > > > + return PTR_ERR(rtc->rtc_map);
> > > > +
> > > > + rtc->irq = platform_get_irq(pdev, 0);
> > > > + if (rtc->irq < 0)
> > > > + return rtc->irq;
> > > > +
> > > > + ret = devm_request_irq(&pdev->dev, rtc->irq, cv1800_rtc_irq_handler,
> > > > + IRQF_TRIGGER_HIGH, "alarm", &pdev->dev);
> > > > + if (ret)
> > > > + return dev_err_probe(&pdev->dev, ret,
> > > > + "cannot register interrupt handler\n");
> > > > +
> > > > + rtc->clk = devm_clk_get(rtc->dev, NULL);
> > > > + if (IS_ERR(rtc->clk))
> > > > + return PTR_ERR(rtc->clk);
> > > > +
> > >
> > > You are going to leak rtc->clk after the next call.
> >
> > I will release him at the appropriate time. And add the remove
> > function to release.
> >
> > >
> > > > + rtc->clk = devm_clk_get_enabled(&pdev->dev, NULL);
> > > > + if (IS_ERR(rtc->clk))
> > > > + return dev_err_probe(&pdev->dev, PTR_ERR(rtc->clk),
> > > > + "clk not found\n");
> > > > +
> > > > + platform_set_drvdata(pdev, rtc);
> > > > +
> > > > + spin_lock_init(&rtc->rtc_lock);
> > > > +
> > > > + rtc->rtc_dev = devm_rtc_device_register(&pdev->dev,
> > > > + dev_name(&pdev->dev),
> > > > + &cv800b_rtc_ops,
> > > > + THIS_MODULE);
> > > > + if (IS_ERR(rtc->rtc_dev))
> > > > + return dev_err_probe(&pdev->dev, PTR_ERR(rtc->rtc_dev),
> > > > + "can't register rtc device\n");
> > >
> > > Please use devm_rtc_allocate_device and devm_rtc_register_device
> >
> > ok,I will use it.
>
> Also you have to set the RTC range properly.
Thanks,I will fix it.
Best regards,
Jingbao Qiu
>
>
> --
> Alexandre Belloni, co-owner and COO, Bootlin
> Embedded Linux and Kernel engineering
> https://bootlin.com
next prev parent reply other threads:[~2023-12-28 4:12 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-12-26 10:04 [PATCH v3 0/4] riscv: rtc: sophgo: add mfd and rtc support for CV1800 Jingbao Qiu
2023-12-26 10:04 ` [PATCH v3 1/4] dt-bindings: mfd: sophgo: add MFD subsys support for Sophgo CV1800 series SoC Jingbao Qiu
2023-12-26 11:38 ` Rob Herring
2023-12-27 7:05 ` Jingbao Qiu
2023-12-26 12:18 ` Krzysztof Kozlowski
2023-12-27 7:35 ` Jingbao Qiu
2023-12-27 11:37 ` Krzysztof Kozlowski
2023-12-27 11:41 ` Jingbao Qiu
2023-12-26 12:21 ` Krzysztof Kozlowski
2023-12-27 7:37 ` Jingbao Qiu
2023-12-26 10:04 ` [PATCH v3 2/4] dt-bindings: rtc: sophgo: add RTC " Jingbao Qiu
2023-12-26 11:38 ` Rob Herring
2023-12-26 10:04 ` [PATCH v3 3/4] rtc: sophgo: add rtc support for Sophgo CV1800 SoC Jingbao Qiu
2023-12-26 12:37 ` Alexandre Belloni
2023-12-27 8:03 ` Jingbao Qiu
2023-12-27 13:50 ` Alexandre Belloni
2023-12-28 4:12 ` Jingbao Qiu [this message]
2023-12-26 10:04 ` [PATCH v3 4/4] riscv: dts: sophgo: add rtc dt node for CV1800 Jingbao Qiu
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=CAJRtX8Qehq-E+Z9T+fc6r36dtF8ZMNwyqxF3WGOQAmwHZHgLkw@mail.gmail.com \
--to=qiujingbao.dlmu@gmail.com \
--cc=a.zummo@towertech.it \
--cc=alexandre.belloni@bootlin.com \
--cc=aou@eecs.berkeley.edu \
--cc=chao.wei@sophgo.com \
--cc=conor+dt@kernel.org \
--cc=conor@kernel.org \
--cc=devicetree@vger.kernel.org \
--cc=dlan@gentoo.org \
--cc=inochiama@outlook.com \
--cc=krzysztof.kozlowski+dt@linaro.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-rtc@vger.kernel.org \
--cc=palmer@dabbelt.com \
--cc=paul.walmsley@sifive.com \
--cc=robh+dt@kernel.org \
--cc=unicorn_wang@outlook.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 read-only IMAP folder(s) and NNTP newsgroup(s).