From: Nishanth Menon <nm@ti.com> To: "H. Nikolaus Schaller" <hns@goldelico.com>, Tony Lindgren <tony@atomide.com> Cc: "Grygorii Strashko" <grygorii.strashko@ti.com>, "Laxman Dewangan" <ldewangan@nvidia.com>, "Benoît Cousson" <bcousson@baylibre.com>, "Rob Herring" <robh+dt@kernel.org>, "Pawel Moll" <pawel.moll@arm.com>, "Mark Rutland" <mark.rutland@arm.com>, "Ian Campbell" <ijc+devicetree@hellion.org.uk>, "Kumar Gala" <galak@codeaurora.org>, "Russell King" <linux@arm.linux.org.uk>, linux-omap <linux-omap@vger.kernel.org>, devicetree@vger.kernel.org, LKML <linux-kernel@vger.kernel.org>, "Marek Belisko" <marek@goldelico.com>, "Gražvydas Ignotas" <notasas@gmail.com>, Keerthy <j-keerthy@ti.com> Subject: Re: [PATCH 1/3] ARM: dts: omap5-board-common: enable rtc and charging of backup battery Date: Wed, 13 Jan 2016 12:31:28 -0600 [thread overview] Message-ID: <56969800.5010206@ti.com> (raw) In-Reply-To: <2B99611A-5D2E-4D17-A17D-0150516109FD@goldelico.com> On 01/13/2016 12:08 PM, H. Nikolaus Schaller wrote: [...] >> OK. So are we sure the TWL driver will never have to toggle this pin? > > After studying the Palmas TRM it appears that this pin just should be "high" > to be able to write to RTC and some scratchpad register. If the Palmas OTP > is programmed to use gpio7 as msecure input. Thanks for digging it up. we dont use the scratchpad, but in some cases where SoC cold reset is involved, those registers may store additional information. > > Since the scratchpad is not used we can permanently enable msecure. Which > means that we must somehow get the driving output to be "1". > > This can be either done by > * a gpio with pull-up - switched to input mode as I proposed, or I think you intended to suggest to do a mux to gpio with just pinmux pull? The internal pull on padconf is very weak - for typical needs like these, it is rather suggested to stick with real GPIO drive to prevent conditions like noise interference(for example). -- Regards, Nishanth Menon
WARNING: multiple messages have this Message-ID (diff)
From: Nishanth Menon <nm-l0cyMroinI0@public.gmane.org> To: "H. Nikolaus Schaller" <hns-xXXSsgcRVICgSpxsJD1C4w@public.gmane.org>, Tony Lindgren <tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org> Cc: "Grygorii Strashko" <grygorii.strashko-l0cyMroinI0@public.gmane.org>, "Laxman Dewangan" <ldewangan-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>, "Benoît Cousson" <bcousson-rdvid1DuHRBWk0Htik3J/w@public.gmane.org>, "Rob Herring" <robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>, "Pawel Moll" <pawel.moll-5wv7dgnIgG8@public.gmane.org>, "Mark Rutland" <mark.rutland-5wv7dgnIgG8@public.gmane.org>, "Ian Campbell" <ijc+devicetree-KcIKpvwj1kUDXYZnReoRVg@public.gmane.org>, "Kumar Gala" <galak-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>, "Russell King" <linux-lFZ/pmaqli7XmaaqVzeoHQ@public.gmane.org>, linux-omap <linux-omap-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, LKML <linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>, "Marek Belisko" <marek-xXXSsgcRVICgSpxsJD1C4w@public.gmane.org>, "Gražvydas Ignotas" <notasas-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>, Keerthy <j-keerthy-l0cyMroinI0@public.gmane.org> Subject: Re: [PATCH 1/3] ARM: dts: omap5-board-common: enable rtc and charging of backup battery Date: Wed, 13 Jan 2016 12:31:28 -0600 [thread overview] Message-ID: <56969800.5010206@ti.com> (raw) In-Reply-To: <2B99611A-5D2E-4D17-A17D-0150516109FD-xXXSsgcRVICgSpxsJD1C4w@public.gmane.org> On 01/13/2016 12:08 PM, H. Nikolaus Schaller wrote: [...] >> OK. So are we sure the TWL driver will never have to toggle this pin? > > After studying the Palmas TRM it appears that this pin just should be "high" > to be able to write to RTC and some scratchpad register. If the Palmas OTP > is programmed to use gpio7 as msecure input. Thanks for digging it up. we dont use the scratchpad, but in some cases where SoC cold reset is involved, those registers may store additional information. > > Since the scratchpad is not used we can permanently enable msecure. Which > means that we must somehow get the driving output to be "1". > > This can be either done by > * a gpio with pull-up - switched to input mode as I proposed, or I think you intended to suggest to do a mux to gpio with just pinmux pull? The internal pull on padconf is very weak - for typical needs like these, it is rather suggested to stick with real GPIO drive to prevent conditions like noise interference(for example). -- Regards, Nishanth Menon -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html
next prev parent reply other threads:[~2016-01-13 18:31 UTC|newest] Thread overview: 75+ messages / expand[flat|nested] mbox.gz Atom feed top 2016-01-05 12:01 [PATCH 0/3] Enable twl603x-GPADC for some OMAP4/OMAP5 boards and Palmas-RTC for OMAP5 H. Nikolaus Schaller 2016-01-05 12:01 ` [PATCH 1/3] ARM: dts: omap5-board-common: enable rtc and charging of backup battery H. Nikolaus Schaller 2016-01-05 12:01 ` H. Nikolaus Schaller 2016-01-05 23:40 ` Nishanth Menon 2016-01-05 23:40 ` Nishanth Menon 2016-01-06 1:00 ` Tony Lindgren 2016-01-06 1:00 ` Tony Lindgren 2016-01-06 8:11 ` H. Nikolaus Schaller 2016-01-06 16:41 ` Tony Lindgren 2016-01-06 16:41 ` Tony Lindgren 2016-01-06 16:47 ` H. Nikolaus Schaller 2016-01-06 17:09 ` Tony Lindgren 2016-01-06 17:09 ` Tony Lindgren 2016-01-08 17:49 ` H. Nikolaus Schaller 2016-01-08 18:15 ` Tony Lindgren 2016-01-08 18:32 ` H. Nikolaus Schaller 2016-01-08 18:32 ` H. Nikolaus Schaller 2016-01-08 19:04 ` Tony Lindgren 2016-01-08 19:31 ` H. Nikolaus Schaller 2016-01-11 20:24 ` Tony Lindgren 2016-01-12 0:09 ` Tony Lindgren 2016-01-12 0:09 ` Tony Lindgren 2016-01-12 13:30 ` H. Nikolaus Schaller 2016-01-12 13:30 ` H. Nikolaus Schaller 2016-01-12 21:27 ` H. Nikolaus Schaller 2016-01-12 21:37 ` Nishanth Menon 2016-01-12 21:37 ` Nishanth Menon 2016-01-12 22:13 ` Tony Lindgren 2016-01-12 22:13 ` Tony Lindgren 2016-01-13 10:25 ` H. Nikolaus Schaller 2016-01-13 14:55 ` Nishanth Menon 2016-01-13 15:14 ` Grygorii Strashko 2016-01-13 15:14 ` Grygorii Strashko 2016-01-13 16:48 ` Tony Lindgren 2016-01-13 17:12 ` Grygorii Strashko 2016-01-13 17:38 ` Nishanth Menon 2016-01-13 18:00 ` H. Nikolaus Schaller 2016-01-13 18:23 ` Nishanth Menon 2016-01-13 17:29 ` Nishanth Menon 2016-01-13 18:00 ` Tony Lindgren 2016-01-13 18:08 ` H. Nikolaus Schaller 2016-01-13 18:08 ` H. Nikolaus Schaller 2016-01-13 18:31 ` Nishanth Menon [this message] 2016-01-13 18:31 ` Nishanth Menon 2016-01-13 18:44 ` H. Nikolaus Schaller 2016-01-13 18:44 ` H. Nikolaus Schaller 2016-01-13 19:05 ` Nishanth Menon 2016-01-13 19:22 ` Grygorii Strashko 2016-01-13 19:40 ` Tony Lindgren 2016-01-13 22:32 ` Nishanth Menon 2016-01-14 10:01 ` Keerthy 2016-01-14 17:39 ` Nishanth Menon 2016-01-14 17:39 ` Nishanth Menon 2016-01-14 18:35 ` Tony Lindgren 2016-01-14 18:35 ` Tony Lindgren 2016-01-15 14:33 ` H. Nikolaus Schaller 2016-01-15 15:47 ` Tony Lindgren 2016-01-15 17:10 ` Tony Lindgren 2016-01-15 17:10 ` Tony Lindgren 2016-01-15 18:11 ` H. Nikolaus Schaller 2016-08-25 2:43 ` Matthijs van Duin 2016-01-13 18:18 ` Nishanth Menon 2016-01-06 7:42 ` H. Nikolaus Schaller 2016-01-06 8:13 ` Laxman Dewangan 2016-01-06 8:13 ` Laxman Dewangan 2016-01-06 14:36 ` Nishanth Menon 2016-01-06 19:34 ` Rob Herring 2016-01-06 19:34 ` Rob Herring 2016-01-06 19:53 ` Nishanth Menon 2016-01-06 19:53 ` Nishanth Menon 2016-01-08 19:33 ` Rob Herring 2016-01-05 12:01 ` [PATCH 2/3] ARM: dts: omap5-board-common: enable iio gpadc for Palmas H. Nikolaus Schaller 2016-01-05 12:01 ` H. Nikolaus Schaller 2016-01-05 12:01 ` [PATCH 3/3] ARM: dts: twl6030: add gpadc H. Nikolaus Schaller 2016-01-05 12:01 ` H. Nikolaus Schaller
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=56969800.5010206@ti.com \ --to=nm@ti.com \ --cc=bcousson@baylibre.com \ --cc=devicetree@vger.kernel.org \ --cc=galak@codeaurora.org \ --cc=grygorii.strashko@ti.com \ --cc=hns@goldelico.com \ --cc=ijc+devicetree@hellion.org.uk \ --cc=j-keerthy@ti.com \ --cc=ldewangan@nvidia.com \ --cc=linux-kernel@vger.kernel.org \ --cc=linux-omap@vger.kernel.org \ --cc=linux@arm.linux.org.uk \ --cc=marek@goldelico.com \ --cc=mark.rutland@arm.com \ --cc=notasas@gmail.com \ --cc=pawel.moll@arm.com \ --cc=robh+dt@kernel.org \ --cc=tony@atomide.com \ /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: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.