From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Brownell Subject: Re: [patch 2.6.17-rc4-omap-git] rtc-omap, rtc framework driver Date: Tue, 15 Aug 2006 15:01:27 -0700 Message-ID: <200608151501.28384.david-b@pacbell.net> References: <8C5B35906ACE4C48ACB3E1FAC65DB5B6231BA7@dlee08.ent.ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <8C5B35906ACE4C48ACB3E1FAC65DB5B6231BA7@dlee08.ent.ti.com> Content-Disposition: inline List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-omap-open-source-bounces@linux.omap.com Errors-To: linux-omap-open-source-bounces@linux.omap.com To: "Johnson, Steve-OMAP" Cc: linux-omap-open-source@linux.omap.com List-Id: linux-omap@vger.kernel.org On Tuesday 15 August 2006 10:25 am, Johnson, Steve-OMAP wrote: > Hi Dave, >=20 > For OMAP2 and OMAP3, the RTC is in the Power Management companion chip > (TWL92230 and TWL4030). >=20 > Where do you see an RTC on the web site for OMAP2420? The only picture > I see shows the RTC in the companion chip. =46rom www.omap.com, click the left hand option then the JavaScript omap2420 link to reach what I suspect is the same page you list (despite linewrap manglage) and includes this graphic: http://focus.ti.com/graphics/wtbu/blockdiagrams/l4_omap2420.gif which is a GIF that shows an RTC on the omap2420 chip, in the block labeled "Timers, Interrupt Controllers, RTC". The product overview link on that page gives a PDF document which agrees. (Agreed that the 2420 gif shows another RTC, on the PM chip ... but not for 2430/3430.) =2D Dave >=20 > http://focus.ti.com/general/docs/wtbu/wtbuproductcontent.tsp?templateId=3D > 6123&navigationId=3D11990&contentId=3D4671 >=20 > Regards, >=20 > Steve > =20 >=20 > > -----Original Message----- > > From: linux-omap-open-source-bounces@linux.omap.com=20 > > [mailto:linux-omap-open-source-bounces@linux.omap.com] On=20 > > Behalf Of David Brownell > > Sent: Tuesday, August 15, 2006 12:04 PM > > To: linux-omap-open-source@linux.omap.com > > Subject: [patch 2.6.17-rc4-omap-git] rtc-omap, rtc framework driver > >=20 > > Cleaning out my patch queue ... here's an "rtc class" driver.=20 > > Much more suitable for upstream merging than the previous=20 > > version, even though that code has gotten much cleaner over time. > >=20 > > Could someone confirm that this RTC can't actually do system=20 > > wakeups without external hardware support? My documentation=20 > > isn't at all clear on that issue. There's certainly an=20 > > external wakeup signal available, but text also says that the=20 > > alarm irq should work the normal way ... but I don't see that=20 > > happening. It could easily be just a bug in=20 > > enable_irq_wakeup(INT_RTC_ALARM) handling, which ISTR looked=20 > > like a big NOP last I checked (for almost all IRQs). > >=20 > > Also, someone with an OMAP2 setup should confirm that the=20 > > Kconfig is right, and this particular controller isn't=20 > > provided on OMAP2. That certainly matches the lack of RTC in=20 > > the .../mach-omap2 directory, but the TI website says 2420=20 > > (but not {2,3}430) has an RTC. Maybe the OMAP 2420 support=20 > > is just missing, and it's really the same RTC... > >=20 > > - Dave > >=20 > >=20 > > This creates a new RTC-framework driver for the RTC/calendar=20 > > module found in various OMAP chips, giving a more=20 > > correct/standard replacement for the older=20 > > drivers/char/omap-rtc.c driver. Differences include: > >=20 > > - much smaller/simpler, because it reuses shared infrastructure > > - the RTC name will normally be "rtc0" not "rtc" > > - the /dev node has a different major and minor numbers > > - RTC_ALM_SET handled as on PCs (alarm within 24 hours) > > - RTC_WKALM_SET handled as on PCs (alarm within this century) > > - epoch not changeable (why bother) > > - rtc alarm may optionally be a system wakeup event (board-specific) > > =20 > > If you use udev and statically link this, some init script=20 > > can just create a symbolic link (rtc -> rtc0) so tools like=20 > > "hwclock" will work as usual. > > Or, updates to hwclock (and busybox) are available which=20 > > teach it to use the /dev/rtc0 path as a backup, and to=20 > > support "hwclock --file=3D/dev/rtc0".=20 > >=20 > > Signed-off-by: David Brownell > >=20 > > ---- > > Presumably an upstream merge should remove the devices.c=20 > > support for the older non-framework driver. > >=20 > > arch/arm/mach-omap1/devices.c | 2=20 > > drivers/rtc/Kconfig | 8=20 > > drivers/rtc/Makefile | 1=20 > > drivers/rtc/rtc-omap.c | 573=20 > > ++++++++++++++++++++++++++++++++++++++++++ > > 4 files changed, 583 insertions(+), 1 deletion(-) > >=20 > > ... deletia ...