From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from metis.ext.pengutronix.de ([2001:6f8:1178:4:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1X5U2i-0006KT-7s for barebox@lists.infradead.org; Fri, 11 Jul 2014 06:10:49 +0000 Date: Fri, 11 Jul 2014 08:10:26 +0200 From: Sascha Hauer Message-ID: <20140711061026.GM23235@pengutronix.de> References: <1404981199-21293-1-git-send-email-antonynpavlov@gmail.com> <20140711053738.GJ23235@pengutronix.de> <20140711101236.5c332b13de1fe7c297237fc5@gmail.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20140711101236.5c332b13de1fe7c297237fc5@gmail.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: Re: [RFC 0/5] add rtc support To: Antony Pavlov Cc: barebox@lists.infradead.org On Fri, Jul 11, 2014 at 10:12:36AM +0400, Antony Pavlov wrote: > On Fri, 11 Jul 2014 07:37:38 +0200 > Sascha Hauer wrote: > > > On Thu, Jul 10, 2014 at 12:33:14PM +0400, Antony Pavlov wrote: > > > This patchseries imports RTC support from linux-3.15. > > > > > > User can use 'hwclock' command to see realtime clock readout. > > > > > > Tested with DS1307. > > > > > > TODOs: > > > > > > * rtc_set_time() is not realized; > > > * ds1307_set_time() is not tested; > > > * bcd lib is compiled in even if rtc support is disabled (as linux does); > > > we can make it optional; > > > > It's probably not worth it. The linker will throw it away anyway if > > unused. > > Hmm, I have missed this. > > In this case can we drop I2C_SMBUS Kconfig stuff > > +config I2C_SMBUS > + bool > + > > +obj-$(CONFIG_I2C_SMBUS) += i2c-smbus.o > > from 'add driver for PCA95[357]x, ...' series? > > Anyway CONFIG_I2C_SMBUS has another meaning in linux. > > > > > > * adjust include/linux/rtc.h and include/rtc.h; > > > * rtc_unregister() is not realized. > > > > Maybe an environment variable which holds the seconds since epoch would > > be useful. This way scripts could make use of the current RTC time. > > So you propose to add an option to hwclock command to store RTC readout into variable, > isn't it? Yes. This would allow scripts to compare times or to store the current time in some boot log. > > I have an idea to put epoch offset (number of years into AD to which a zero year value > in the Hardware Clock refers) into "global.epoch" variable and add corresponding > Kconfig option for default epoch value. Does Linux support such a mechanism aswell? How can we make sure Linux uses the same epoch offset? Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox