Linux-RTC Archive on lore.kernel.org
 help / color / Atom feed
From: "Jonathan Neuschäfer" <j.neuschaefer@gmx.net>
To: Andreas Kemnade <andreas@kemnade.info>
Cc: "Jonathan Neuschäfer" <j.neuschaefer@gmx.net>,
	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>,
	"Alexandre Belloni" <alexandre.belloni@bootlin.com>,
	"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>
Subject: Re: [RFC PATCH 04/10] mfd: Add base driver for Netronix embedded controller
Date: Sun, 28 Jun 2020 10:29:06 +0200
Message-ID: <20200628082906.GB2561@latitude> (raw)
In-Reply-To: <20200627101738.2fe4abc3@aktux>


[-- Attachment #1: Type: text/plain, Size: 1983 bytes --]

On Sat, Jun 27, 2020 at 10:17:38AM +0200, Andreas Kemnade wrote:
> On Sun, 21 Jun 2020 00:42:15 +0200
> Jonathan Neuschäfer <j.neuschaefer@gmx.net> wrote:
> 
> > Third-party hardware documentation is available at
> > https://github.com/neuschaefer/linux/wiki/Netronix-MSP430-embedded-controller
> > 
> > The EC supports interrupts, but the driver doesn't make use of them so
> > far.
> > 
> > Known problems:
> > - The reboot handler is installed in such a way that it directly calls
> >   into the i2c subsystem to send the reboot command to the EC. This
> >   means that the reboot handler may sleep, which is not allowed.
> > 
> see
> https://patchwork.ozlabs.org/project/linux-i2c/patch/20190415213432.8972-3-contact@stefanchrist.eu/
> 
> for a fix of such problems. 

So far, regmap isn't involved here, but I'll remember it when I switch
to regmap.

Between when I first wrote this driver and now, the I2C has added
support for transfers in atomic contexts very late in the system's life
(exactly what happens when you reset a system via PMIC/EC), so this
problem seems to be gone from my driver, for now.
(See commit 63b96983a5ddf ("i2c: core: introduce callbacks for atomic transfers"))


[...]
> > +int ntxec_write8(struct ntxec *ec, u8 addr, u8 value)
> > +{
> > +	return ntxec_write16(ec, addr, value << 8);
> > +}
> > +EXPORT_SYMBOL(ntxec_write8);
> > +
> 
> do we really need both 16bit and 8bit accessors?

No, the hardware/firmware doesn't care.

> If not, then simply use regmap_i2c_init and set val_bits accordingly.
> Maybe just doing the << 8 in the constants?

Thanks, I'll try this approach.

The values are not always constants, for example in the PWM driver:

	res |= ntxec_write8(pwm->ec, NTXEC_PERIOD_HIGH, period >> 8);
	res |= ntxec_write8(pwm->ec, NTXEC_PERIOD_LOW, period);
	res |= ntxec_write8(pwm->ec, NTXEC_DUTY_HIGH, duty >> 8);
	res |= ntxec_write8(pwm->ec, NTXEC_DUTY_LOW, duty);


Jonathan

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]

  reply index

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-20 22:42 [RFC PATCH 02/10] dt-bindings: Add vendor prefix for Netronix, Inc Jonathan Neuschäfer
2020-06-20 22:42 ` [RFC PATCH 03/10] dt-bindings: mfd: Add binding for Netronix's embedded controller Jonathan Neuschäfer
2020-06-20 22:42 ` [RFC PATCH 04/10] mfd: Add base driver for Netronix " Jonathan Neuschäfer
2020-06-22 10:55   ` Lee Jones
2020-06-28  8:11     ` Jonathan Neuschäfer
2020-06-27  8:17   ` Andreas Kemnade
2020-06-28  8:29     ` Jonathan Neuschäfer [this message]
2020-06-20 22:42 ` [RFC PATCH 05/10] dt-bindings: pwm: Add bindings for PWM function in Netronix EC Jonathan Neuschäfer
2020-06-21 18:41   ` Andreas Kemnade
2020-06-20 22:42 ` [RFC PATCH 06/10] pwm: ntxec: Add driver " Jonathan Neuschäfer
2020-06-22  8:18   ` Uwe Kleine-König
2020-07-03 16:15     ` Jonathan Neuschäfer
2020-06-20 22:42 ` [RFC PATCH 07/10] dt-bindings: rtc: Add bindings for Netronix embedded controller RTC Jonathan Neuschäfer
2020-06-21  0:02   ` Alexandre Belloni
2020-06-26 21:55     ` Andreas Kemnade
2020-07-03 17:04       ` Jonathan Neuschäfer
2020-06-20 22:42 ` [RFC PATCH 08/10] rtc: New driver for RTC in Netronix embedded controller Jonathan Neuschäfer
2020-06-21  0:11   ` Alexandre Belloni
2020-07-04 19:23     ` Jonathan Neuschäfer
2020-06-20 22:42 ` [RFC PATCH 09/10] MAINTAINERS: Add entry for " Jonathan Neuschäfer
2020-06-20 22:42 ` [RFC PATCH 10/10] ARM: dts: imx50-kobo-aura: Add " Jonathan Neuschäfer
2020-06-20 22:46 ` [RFC PATCH 02/10] dt-bindings: Add vendor prefix for Netronix, Inc 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=20200628082906.GB2561@latitude \
    --to=j.neuschaefer@gmx.net \
    --cc=a.zummo@towertech.it \
    --cc=alexandre.belloni@bootlin.com \
    --cc=allen.chen@ite.com.tw \
    --cc=andreas@kemnade.info \
    --cc=broonie@kernel.org \
    --cc=davem@davemloft.net \
    --cc=devicetree@vger.kernel.org \
    --cc=festevam@gmail.com \
    --cc=heiko.stuebner@theobroma-systems.com \
    --cc=heiko@sntech.de \
    --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

Linux-RTC Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-rtc/0 linux-rtc/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-rtc linux-rtc/ https://lore.kernel.org/linux-rtc \
		linux-rtc@vger.kernel.org
	public-inbox-index linux-rtc

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-rtc


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git