From mboxrd@z Thu Jan 1 00:00:00 1970 From: marex@denx.de (Marek Vasut) Date: Mon, 20 Jul 2015 10:15:06 +0200 Subject: [PATCH V4 RFC 2/3] nvmem: add driver for ocotp in i.MX23 and i.MX28 In-Reply-To: <55AC9901.1040402@i2se.com> References: <1437343499-16422-1-git-send-email-stefan.wahren@i2se.com> <201507200012.13608.marex@denx.de> <55AC9901.1040402@i2se.com> Message-ID: <201507201015.07075.marex@denx.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Monday, July 20, 2015 at 08:45:21 AM, Stefan Wahren wrote: > Hi Marek, Hi! > Am 20.07.2015 um 00:12 schrieb Marek Vasut: > > On Monday, July 20, 2015 at 12:04:58 AM, Stefan Wahren wrote: > >> This patch brings read-only support for the On-Chip OTP cells > >> in the i.MX23 and i.MX28 processor. The driver implements the > >> new NVMEM provider API. > >> > >> Signed-off-by: Stefan Wahren > > > > How come this driver isn't doing any manipulation with the VDDIO > > voltage -- or did I miss that? I seem to remember that the VDDIO > > had to be lowered to 2.8V before the fuses could be programmed > > and restored to 3.3V afterward. See for example recent mainline > > u-boot, drivers/misc/mxs_ocotp.c . > > Why should the driver implement VDDIO manipulation when there is only > read-only support for the OTP bits? There is no ambition to implement > write support. Maybe i should clarify that in the comments. Urm, sorry, I missed that read-only part. I apologize. > Btw i'm on your side that because programming the OTP from userspace is > to dangerous. :) Best regards, Marek Vasut From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marek Vasut Subject: Re: [PATCH V4 RFC 2/3] nvmem: add driver for ocotp in i.MX23 and i.MX28 Date: Mon, 20 Jul 2015 10:15:06 +0200 Message-ID: <201507201015.07075.marex@denx.de> References: <1437343499-16422-1-git-send-email-stefan.wahren@i2se.com> <201507200012.13608.marex@denx.de> <55AC9901.1040402@i2se.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <55AC9901.1040402-eS4NqCHxEME@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Stefan Wahren Cc: Mark Rutland , Fabio Estevam , Pawel Moll , Ian Campbell , Sanchayan Maity , devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Rob Herring , Srinivas Kandagatla , Sascha Hauer , Kumar Gala , Maxime Ripard , Shawn Guo , linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: devicetree@vger.kernel.org On Monday, July 20, 2015 at 08:45:21 AM, Stefan Wahren wrote: > Hi Marek, Hi! > Am 20.07.2015 um 00:12 schrieb Marek Vasut: > > On Monday, July 20, 2015 at 12:04:58 AM, Stefan Wahren wrote: > >> This patch brings read-only support for the On-Chip OTP cells > >> in the i.MX23 and i.MX28 processor. The driver implements the > >> new NVMEM provider API. > >> > >> Signed-off-by: Stefan Wahren > > > > How come this driver isn't doing any manipulation with the VDDIO > > voltage -- or did I miss that? I seem to remember that the VDDIO > > had to be lowered to 2.8V before the fuses could be programmed > > and restored to 3.3V afterward. See for example recent mainline > > u-boot, drivers/misc/mxs_ocotp.c . > > Why should the driver implement VDDIO manipulation when there is only > read-only support for the OTP bits? There is no ambition to implement > write support. Maybe i should clarify that in the comments. Urm, sorry, I missed that read-only part. I apologize. > Btw i'm on your side that because programming the OTP from userspace is > to dangerous. :) Best regards, Marek Vasut -- 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