From: Linus Walleij <linus.walleij@linaro.org>
To: christophe.kerello@st.com
Cc: "Boris Brezillon" <boris.brezillon@bootlin.com>,
"Miquèl Raynal" <miquel.raynal@bootlin.com>,
"Richard Weinberger" <richard@nod.at>,
"David Woodhouse" <dwmw2@infradead.org>,
"Brian Norris" <computersforpeace@gmail.com>,
"Mark Vasut" <marek.vasut@gmail.com>,
"Rob Herring" <robh+dt@kernel.org>,
"Mark Rutland" <mark.rutland@arm.com>,
linux-mtd@lists.infradead.org,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS"
<devicetree@vger.kernel.org>,
linux-stm32@st-md-mailman.stormreply.com
Subject: Re: [ v3 2/3] mtd: rawnand: stm32_fmc2: add STM32 FMC2 NAND flash controller driver
Date: Fri, 7 Dec 2018 10:06:03 +0100 [thread overview]
Message-ID: <CACRpkdb83-kEwrip+t8g2VVFiREXspfWKQa2=Zd1ah1sSLNHjQ@mail.gmail.com> (raw)
In-Reply-To: <1543509663-26128-3-git-send-email-christophe.kerello@st.com>
Hi Christophe,
On Thu, Nov 29, 2018 at 5:42 PM Christophe Kerello
<christophe.kerello@st.com> wrote:
> +/* FMC2 Controller Registers */
> +#define FMC2_BCR1 0x0
> +#define FMC2_PCR 0x80
(...)
> +/* Register: FMC2_BCR1 */
> +#define FMC2_BCR1_FMC2EN BIT(31)
Well this looks like an especially clever register map and a specific choice
of bit 31 in the fist register to activate FMC2. Registers 0x04 thru
0x7c are completely unused save for one bit.
It's almost like this is the good old FSMC integrated in parallel with FMC2,
so that if you don't set bit 31, this becomes something that can be used
with drivers/mtd/nand/raw/fsmc_nand.c, and FMC2 mode is activated
by setting this bit, activating all the new registers.
It wouldn't surprise me given how HW designers like to work.
Is this the case?
If that is the case I think it should at least be mentioned in commit
logs and DT bindings and possibly in a comment on the driver
itself.
Yours,
Linus Walleij
next prev parent reply other threads:[~2018-12-07 9:06 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-29 16:41 [ v3 0/3] mtd: rawnand: add STM32 FMC2 NAND flash controller driver Christophe Kerello
2018-11-29 16:41 ` [ v3 1/3] dt-bindings: mtd: stm32_fmc2: add STM32 FMC2 NAND controller documentation Christophe Kerello
2018-12-07 23:42 ` Rob Herring
2018-11-29 16:41 ` [ v3 2/3] mtd: rawnand: stm32_fmc2: add STM32 FMC2 NAND flash controller driver Christophe Kerello
2018-12-07 9:06 ` Linus Walleij [this message]
2018-12-07 10:21 ` [Linux-stm32] " Benjamin GAIGNARD
2018-12-07 12:47 ` Linus Walleij
2018-12-07 16:53 ` Christophe Kerello
2018-12-13 10:45 ` Linus Walleij
2018-12-07 10:18 ` Miquel Raynal
2018-12-07 10:53 ` Christophe Kerello
2018-11-29 16:41 ` [ v3 3/3] mtd: rawnand: stm32_fmc2: add manual mode Christophe Kerello
2018-12-07 9:16 ` Linus Walleij
2018-12-07 10:56 ` Christophe Kerello
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='CACRpkdb83-kEwrip+t8g2VVFiREXspfWKQa2=Zd1ah1sSLNHjQ@mail.gmail.com' \
--to=linus.walleij@linaro.org \
--cc=boris.brezillon@bootlin.com \
--cc=christophe.kerello@st.com \
--cc=computersforpeace@gmail.com \
--cc=devicetree@vger.kernel.org \
--cc=dwmw2@infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mtd@lists.infradead.org \
--cc=linux-stm32@st-md-mailman.stormreply.com \
--cc=marek.vasut@gmail.com \
--cc=mark.rutland@arm.com \
--cc=miquel.raynal@bootlin.com \
--cc=richard@nod.at \
--cc=robh+dt@kernel.org \
/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: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).