linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Alexandre Belloni <alexandre.belloni@bootlin.com>
To: "Jonathan Neuschäfer" <j.neuschaefer@gmx.net>
Cc: linux-kernel@vger.kernel.org, "Lee Jones" <lee.jones@linaro.org>,
	"Rob Herring" <robh+dt@kernel.org>,
	"Thierry Reding" <thierry.reding@gmail.com>,
	"Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>,
	"Alessandro Zummo" <a.zummo@towertech.it>,
	"Shawn Guo" <shawnguo@kernel.org>,
	"Sascha Hauer" <s.hauer@pengutronix.de>,
	"Pengutronix Kernel Team" <kernel@pengutronix.de>,
	"Fabio Estevam" <festevam@gmail.com>,
	"NXP Linux Team" <linux-imx@nxp.com>,
	"Sam Ravnborg" <sam@ravnborg.org>,
	"Linus Walleij" <linus.walleij@linaro.org>,
	"Heiko Stuebner" <heiko.stuebner@theobroma-systems.com>,
	"Stephan Gerhold" <stephan@gerhold.net>,
	"Lubomir Rintel" <lkundrak@v3.sk>,
	"Mark Brown" <broonie@kernel.org>, allen <allen.chen@ite.com.tw>,
	"Mauro Carvalho Chehab" <mchehab+huawei@kernel.org>,
	"David S. Miller" <davem@davemloft.net>,
	devicetree@vger.kernel.org, linux-pwm@vger.kernel.org,
	linux-rtc@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	"Heiko Stuebner" <heiko@sntech.de>,
	"Josua Mayer" <josua.mayer@jm0.eu>,
	"Andreas Kemnade" <andreas@kemnade.info>,
	"Arnd Bergmann" <arnd@arndb.de>,
	"Daniel Palmer" <daniel@0x0f.com>,
	"Andy Shevchenko" <andy.shevchenko@gmail.com>
Subject: Re: [PATCH v4 5/7] rtc: New driver for RTC in Netronix embedded controller
Date: Mon, 23 Nov 2020 00:10:54 +0100	[thread overview]
Message-ID: <20201122231054.GH348979@piout.net> (raw)
In-Reply-To: <20201122222739.1455132-6-j.neuschaefer@gmx.net>

Hi,

On 22/11/2020 23:27:37+0100, Jonathan Neuschäfer wrote:
> With this driver, mainline Linux can keep its time and date in sync with
> the vendor kernel.
> 
> Advanced functionality like alarm and automatic power-on is not yet
> supported.
> 
> Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

However, two comments below:

> +static int ntxec_set_time(struct device *dev, struct rtc_time *tm)
> +{
> +	struct ntxec_rtc *rtc = dev_get_drvdata(dev);
> +	int res = 0;
> +
> +	/*
> +	 * To avoid time overflows while we're writing the full date/time,
> +	 * set the seconds field to zero before doing anything else. For the
> +	 * next 59 seconds (plus however long it takes until the RTC's next
> +	 * update of the second field), the seconds field will not overflow
> +	 * into the other fields.
> +	 */
> +	res = regmap_write(rtc->ec->regmap, NTXEC_REG_WRITE_SECOND, ntxec_reg8(0));
> +	if (res)
> +		return res;
> +
> +	res = regmap_write(rtc->ec->regmap, NTXEC_REG_WRITE_YEAR, ntxec_reg8(tm->tm_year - 100));
> +	if (res)
> +		return res;
> +
> +	res = regmap_write(rtc->ec->regmap, NTXEC_REG_WRITE_MONTH, ntxec_reg8(tm->tm_mon + 1));
> +	if (res)
> +		return res;
> +
> +	res = regmap_write(rtc->ec->regmap, NTXEC_REG_WRITE_DAY, ntxec_reg8(tm->tm_mday));
> +	if (res)
> +		return res;
> +
> +	res = regmap_write(rtc->ec->regmap, NTXEC_REG_WRITE_HOUR, ntxec_reg8(tm->tm_hour));
> +	if (res)
> +		return res;
> +
> +	res = regmap_write(rtc->ec->regmap, NTXEC_REG_WRITE_MINUTE, ntxec_reg8(tm->tm_min));
> +	if (res)
> +		return res;
> +
> +	return regmap_write(rtc->ec->regmap, NTXEC_REG_WRITE_SECOND, ntxec_reg8(tm->tm_sec));

Couldn't you do a regmap_block_write or a regmap_multi_reg_write which
would be more efficient as they would be locking the regmap only once.

> +}
> +
> +static const struct rtc_class_ops ntxec_rtc_ops = {
> +	.read_time = ntxec_read_time,
> +	.set_time = ntxec_set_time,
> +};
> +
> +static int ntxec_rtc_probe(struct platform_device *pdev)
> +{
> +	struct rtc_device *dev;
> +	struct ntxec_rtc *rtc;
> +
> +	rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
> +	if (!rtc)
> +		return -ENOMEM;
> +
> +	rtc->dev = &pdev->dev;
> +	rtc->ec = dev_get_drvdata(pdev->dev.parent);
> +	platform_set_drvdata(pdev, rtc);
> +
> +	dev = devm_rtc_allocate_device(&pdev->dev);
> +	if (IS_ERR(dev))
> +		return PTR_ERR(dev);
> +
> +	dev->ops = &ntxec_rtc_ops;
> +	dev->range_min = RTC_TIMESTAMP_BEGIN_2000;
> +	dev->range_max = 9025257599LL; /* 2255-12-31 23:59:59 */
> +
> +	return rtc_register_device(dev);

Note that this won't compile after
https://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux.git/commit/?id=fdcfd854333be5b30377dc5daa9cd0fa1643a979

We can solve that with immutable branches though.

-- 
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com

  reply	other threads:[~2020-11-22 23:11 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-22 22:27 [PATCH v4 0/7] Netronix embedded controller driver for Kobo and Tolino ebook readers Jonathan Neuschäfer
2020-11-22 22:27 ` [PATCH v4 1/7] dt-bindings: Add vendor prefix for Netronix, Inc Jonathan Neuschäfer
2020-11-22 22:27 ` [PATCH v4 2/7] dt-bindings: mfd: Add binding for Netronix embedded controller Jonathan Neuschäfer
2020-11-22 22:27 ` [PATCH v4 3/7] mfd: Add base driver " Jonathan Neuschäfer
2020-12-02 13:05   ` Lee Jones
2020-12-02 13:06     ` Lee Jones
2020-12-02 14:00     ` Jonathan Neuschäfer
2020-12-02 15:09       ` Lee Jones
2020-12-02 17:11         ` Jonathan Neuschäfer
2020-11-22 22:27 ` [PATCH v4 4/7] pwm: ntxec: Add driver for PWM function in Netronix EC Jonathan Neuschäfer
2020-11-24  8:20   ` Uwe Kleine-König
2020-11-26 23:19     ` Jonathan Neuschäfer
2020-11-27  7:11       ` Uwe Kleine-König
2020-11-27 11:08         ` Thierry Reding
2020-11-27 14:23           ` Uwe Kleine-König
2020-11-29 17:59             ` Jonathan Neuschäfer
2020-11-29 17:48         ` Jonathan Neuschäfer
2020-11-22 22:27 ` [PATCH v4 5/7] rtc: New driver for RTC in Netronix embedded controller Jonathan Neuschäfer
2020-11-22 23:10   ` Alexandre Belloni [this message]
2020-11-23 21:31     ` Jonathan Neuschäfer
2020-11-23 21:34       ` Mark Brown
2020-11-23 21:38       ` Alexandre Belloni
2020-11-22 22:27 ` [PATCH v4 6/7] MAINTAINERS: Add entry for " Jonathan Neuschäfer
2020-11-23  0:09 ` [PATCH v4 7/7] ARM: dts: imx50-kobo-aura: Add " Jonathan Neuschäfer

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=20201122231054.GH348979@piout.net \
    --to=alexandre.belloni@bootlin.com \
    --cc=a.zummo@towertech.it \
    --cc=allen.chen@ite.com.tw \
    --cc=andreas@kemnade.info \
    --cc=andy.shevchenko@gmail.com \
    --cc=arnd@arndb.de \
    --cc=broonie@kernel.org \
    --cc=daniel@0x0f.com \
    --cc=davem@davemloft.net \
    --cc=devicetree@vger.kernel.org \
    --cc=festevam@gmail.com \
    --cc=heiko.stuebner@theobroma-systems.com \
    --cc=heiko@sntech.de \
    --cc=j.neuschaefer@gmx.net \
    --cc=josua.mayer@jm0.eu \
    --cc=kernel@pengutronix.de \
    --cc=lee.jones@linaro.org \
    --cc=linus.walleij@linaro.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-imx@nxp.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-pwm@vger.kernel.org \
    --cc=linux-rtc@vger.kernel.org \
    --cc=lkundrak@v3.sk \
    --cc=mchehab+huawei@kernel.org \
    --cc=robh+dt@kernel.org \
    --cc=s.hauer@pengutronix.de \
    --cc=sam@ravnborg.org \
    --cc=shawnguo@kernel.org \
    --cc=stephan@gerhold.net \
    --cc=thierry.reding@gmail.com \
    --cc=u.kleine-koenig@pengutronix.de \
    /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).