From: Miquel Raynal <miquel.raynal@bootlin.com>
To: masonccyang@mxic.com.tw
Cc: mark.rutland@arm.com, devicetree@vger.kernel.org,
christophe.kerello@st.com, bbrezillon@kernel.org,
juliensu@mxic.com.tw, lee.jones@linaro.org,
linux-kernel@vger.kernel.org, robh+dt@kernel.org,
linux-spi@vger.kernel.org, marcel.ziswiler@toradex.com,
paul.burton@mips.com, broonie@kernel.org, geert@linux-m68k.org,
stefan@agner.ch, linux-mtd@lists.infradead.org, richard@nod.at,
liang.yang@amlogic.com, computersforpeace@gmail.com,
dwmw2@infradead.org, marek.vasut@gmail.com,
zhengxunli@mxic.com.tw
Subject: Re: [PATCH v3 2/4] mtd: rawnand: Add Macronix MX25F0A NAND controller
Date: Mon, 17 Jun 2019 14:35:10 +0200 [thread overview]
Message-ID: <20190617143510.4ded5728@xps13> (raw)
In-Reply-To: <OFE923A8E5.50375C30-ON48258409.0009AE1B-48258409.00119767@mxic.com.tw>
Hi Mason,
masonccyang@mxic.com.tw wrote on Wed, 29 May 2019 11:12:08 +0800:
> Hi Miquel,
>
> > > > > > > +static void mxic_nand_select_chip(struct nand_chip *chip, int
>
> > > chipnr)
> > > > > >
> > > > > > _select_target() is preferred now
> > > > >
> > > > > Do you mean I implement mxic_nand_select_target() to control #CS ?
> > > > >
> > > > > If so, I need to call mxic_nand_select_target( ) to control #CS ON
> > > > > and then #CS OFF in _exec_op() due to nand_select_target()<in
> > > nand_base,c>
> > > > > is still calling chip->legacy.select_chip ?
> > > >
> > > > You must forget about the ->select_chip() callback. Now it should be
> > > > handled directly from the controller driver. Please have a look at
> the
> > > > commit pointed against the marvell_nand.c driver.
> > >
> > > I have no Marvell NFC datasheet and have one question.
> > >
> > > In marvell_nand.c, there is no xxx_deselect_target() or
> > > something like that doing #CS OFF.
> > > marvell_nfc_select_target() seems always to make one of chip or die
> > > #CS keep low.
> > >
> > > Is it right ?
> >
> > Yes, AFAIR there is no "de-assert" mechanism in this controller.
> >
> > >
> > > How to make all #CS keep high for NAND to enter
> > > low-power standby mode if driver don't use "legacy.select_chip()" ?
> >
> > See commit 02b4a52604a4 ("mtd: rawnand: Make ->select_chip() optional
> > when ->exec_op() is implemented") which states:
> >
> > "When [->select_chip() is] not implemented, the core is assuming
> > the CS line is automatically asserted/deasserted by the driver
> > ->exec_op() implementation."
> >
> > Of course, the above is right only when the controller driver supports
> > the ->exec_op() interface.
>
> Currently, it seems that we will get the incorrect data and error
> operation due to CS in error toggling if CS line is controlled in
> ->exec_op().
Most of the chips today are CS-don't-care, which chip are you using?
Is this behavior publicly documented?
Is this LPM mode always activated?
> i.e,.
>
> 1) In nand_onfi_detect() to call nand_exec_op() twice by
> nand_read_param_page_op() and annd_read_data_op()
>
> 2) In nand_write_page_xxx to call nand_exec_op() many times by
> nand_prog_page_begin_op(), nand_write_data_op() and
> nand_prog_page_end_op().
>
>
> Should we consider to add a CS line controller in struct nand_controller
> i.e,.
>
> struct nand_controller {
> struct mutex lock;
> const struct nand_controller_ops *ops;
> + void (*select_chip)(struct nand_chip *chip, int cs);
> };
>
> to replace legacy.select_chip() ?
>
No, if really needed, we could add a "macro op done" flag in the nand
operation structure.
Thanks,
Miquèl
______________________________________________________
Linux MTD discussion mailing list
http://lists.infradead.org/mailman/listinfo/linux-mtd/
next prev parent reply other threads:[~2019-06-17 12:35 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-15 9:23 [PATCH v3 0/4] Add Macronix MX25F0A MFD driver for raw nand and spi Mason Yang
2019-04-15 9:23 ` [PATCH v3 1/4] mfd: Add Macronix MX25F0A MFD controller driver Mason Yang
2019-05-12 13:08 ` Miquel Raynal
2019-05-15 6:46 ` masonccyang
2019-04-15 9:23 ` [PATCH v3 2/4] mtd: rawnand: Add Macronix MX25F0A NAND controller Mason Yang
2019-05-12 13:18 ` Miquel Raynal
2019-05-15 8:48 ` masonccyang
2019-05-15 12:08 ` Miquel Raynal
[not found] ` <OF8A566F14.A2F0F576-ON482583FB.002E7E32-482583FB.003068B1@LocalDomain>
2019-05-15 9:18 ` masonccyang
2019-05-17 9:30 ` masonccyang
2019-05-20 12:23 ` Miquel Raynal
2019-05-23 8:58 ` masonccyang
2019-05-27 12:42 ` Miquel Raynal
2019-05-29 3:12 ` masonccyang
2019-06-17 12:35 ` Miquel Raynal [this message]
2019-06-18 1:24 ` masonccyang
2019-06-18 6:14 ` Boris Brezillon
2019-06-18 7:29 ` Boris Brezillon
2019-06-19 8:04 ` masonccyang
2019-06-19 8:09 ` Miquel Raynal
2019-06-19 8:48 ` masonccyang
2019-06-24 9:05 ` masonccyang
2019-06-19 8:15 ` Boris Brezillon
2019-06-19 8:55 ` masonccyang
2019-06-19 9:06 ` Boris Brezillon
2019-06-24 8:55 ` masonccyang
2019-04-15 9:23 ` [PATCH v3 3/4] spi: Patch Macronix SPI controller driver according to MX25F0A MFD driver Mason Yang
2019-04-19 14:51 ` Mark Brown
[not found] ` <OF7742B4A9.445066F6-ON482583EC.0037E377-482583EC.0039125B@mxic.com.tw>
2019-05-02 2:41 ` Mark Brown
2019-04-15 9:23 ` [PATCH v3 4/4] dt-bindings: mfd: Document Macronix MX25F0A controller bindings Mason Yang
2019-04-26 22:41 ` Rob Herring
2019-05-12 13:23 ` Miquel Raynal
2019-05-15 7:36 ` masonccyang
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=20190617143510.4ded5728@xps13 \
--to=miquel.raynal@bootlin.com \
--cc=bbrezillon@kernel.org \
--cc=broonie@kernel.org \
--cc=christophe.kerello@st.com \
--cc=computersforpeace@gmail.com \
--cc=devicetree@vger.kernel.org \
--cc=dwmw2@infradead.org \
--cc=geert@linux-m68k.org \
--cc=juliensu@mxic.com.tw \
--cc=lee.jones@linaro.org \
--cc=liang.yang@amlogic.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mtd@lists.infradead.org \
--cc=linux-spi@vger.kernel.org \
--cc=marcel.ziswiler@toradex.com \
--cc=marek.vasut@gmail.com \
--cc=mark.rutland@arm.com \
--cc=masonccyang@mxic.com.tw \
--cc=paul.burton@mips.com \
--cc=richard@nod.at \
--cc=robh+dt@kernel.org \
--cc=stefan@agner.ch \
--cc=zhengxunli@mxic.com.tw \
/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).