From mboxrd@z Thu Jan 1 00:00:00 1970 From: khali@linux-fr.org (Jean Delvare) Date: Thu, 16 Jun 2005 19:47:09 +0000 Subject: [lm-sensors] smbus RTC as misc device Message-Id: <20050616194558.402b7253.khali@linux-fr.org> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: lm-sensors@vger.kernel.org Hi Olav, Sorry for the delay. > I hope this is the right list for my question. If not, > please point me to a better list. > > Sometime at 2.6.8-2.6.9 kernel I needed a driver for the > m41t11 RTC smbus chip. As there was none in the kernel at > that time, I wrote it myself and made it available for user > space as a misc device /dev/rtc (character dev 10 135). This > way unmodified hwclock could access it. > > Now I noticed that latest kernels already contain the > m41t00.c, which may well be able to drive my m41t11 RTC > unmodified. However, it does not make the device available > through /dev/rtc. Neither do that other few i2c RTCs > currently in the kernel. They all seem to define their own > ioctls each. > > What about making i2c RTCs available through /dev/rtc > supporting its ioctls? If this would be OK then I can > propose a patch for m41t00.c. You are probably right. There have been quite a few discussions lately about how to standardize the kernel interface to RTC drivers, the same question may hold for the user-space interface. However, this is neither related to hardware monitoring, nor to i2c, so there's not much advice we can give to you - it's something we don't know anything about ourselves. Better try to contact the various authors of RTC drivers and/or the LKML, and see what they think about the idea. -- Jean Delvare