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From: marex@denx.de (Marek Vasut)
To: linux-arm-kernel@lists.infradead.org
Subject: [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	[thread overview]
Message-ID: <201507201015.07075.marex@denx.de> (raw)
In-Reply-To: <55AC9901.1040402@i2se.com>

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 <stefan.wahren@i2se.com>
> > 
> > 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

WARNING: multiple messages have this Message-ID (diff)
From: Marek Vasut <marex-ynQEQJNshbs@public.gmane.org>
To: Stefan Wahren <stefan.wahren-eS4NqCHxEME@public.gmane.org>
Cc: Mark Rutland <mark.rutland-5wv7dgnIgG8@public.gmane.org>,
	Fabio Estevam
	<fabio.estevam-KZfg59tc24xl57MIdRCFDg@public.gmane.org>,
	Pawel Moll <pawel.moll-5wv7dgnIgG8@public.gmane.org>,
	Ian Campbell
	<ijc+devicetree-KcIKpvwj1kUDXYZnReoRVg@public.gmane.org>,
	Sanchayan Maity
	<maitysanchayan-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>,
	devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	Rob Herring <robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
	Srinivas Kandagatla
	<srinivas.kandagatla-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>,
	Sascha Hauer <kernel-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>,
	Kumar Gala <galak-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>,
	Maxime Ripard
	<maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>,
	Shawn Guo <shawn.guo-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>,
	linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org
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	[thread overview]
Message-ID: <201507201015.07075.marex@denx.de> (raw)
In-Reply-To: <55AC9901.1040402-eS4NqCHxEME@public.gmane.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 <stefan.wahren-eS4NqCHxEME@public.gmane.org>
> > 
> > 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
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  reply	other threads:[~2015-07-20  8:15 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-07-19 22:04 [PATCH V4 RFC 0/3] nvmem: add ocotp support for i.MX23 and i.MX28 Stefan Wahren
2015-07-19 22:04 ` Stefan Wahren
2015-07-19 22:04 ` [PATCH V4 RFC 1/3] DT: nvmem: add binding for mxs-ocotp Stefan Wahren
2015-07-19 22:04   ` Stefan Wahren
2015-07-19 22:04 ` [PATCH V4 RFC 2/3] nvmem: add driver for ocotp in i.MX23 and i.MX28 Stefan Wahren
2015-07-19 22:04   ` Stefan Wahren
2015-07-19 22:12   ` Marek Vasut
2015-07-19 22:12     ` Marek Vasut
2015-07-20  6:45     ` Stefan Wahren
2015-07-20  6:45       ` Stefan Wahren
2015-07-20  8:15       ` Marek Vasut [this message]
2015-07-20  8:15         ` Marek Vasut
2015-07-19 22:04 ` [PATCH V4 RFC 3/3] mxs: enable ocotp for " Stefan Wahren
2015-07-19 22:04   ` Stefan Wahren
2015-07-19 22:07 ` [PATCH V4 RFC 0/3] nvmem: add ocotp support " Marek Vasut
2015-07-19 22:07   ` Marek Vasut
2015-07-20  6:37   ` Stefan Wahren
2015-07-20  6:37     ` Stefan Wahren
2015-07-20  8:16     ` Marek Vasut
2015-07-20  8:16       ` Marek Vasut

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