linux-mtd.lists.infradead.org archive mirror
 help / color / mirror / Atom feed
From: <Tudor.Ambarus@microchip.com>
To: <s.hauer@pengutronix.de>
Cc: richard@nod.at, linux-mtd@lists.infradead.org, vigneshr@ti.com,
	kernel@pengutronix.de, miquel.raynal@bootlin.com
Subject: Re: [PATCH v3] mtd: spi-nor: Add support for Cypress cy15x104q
Date: Thu, 28 May 2020 08:12:14 +0000	[thread overview]
Message-ID: <13199742.Uhtxi0mpr9@192.168.0.120> (raw)
In-Reply-To: <20200424065626.8196-1-s.hauer@pengutronix.de>

On Friday, April 24, 2020 9:56:26 AM EEST Sascha Hauer wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the
> content is safe
> 
> The Cypress cy15b104q and cy15v104q are 4Mbit serial SPI F-RAM devices.
> Add support for them to the spi-nor driver.
> 
> The actual Device ID of this chip is 7f 7f 7f 7f 7f 7f c2 2c 04. That is
> six times the continuation code 7f followed by c2 for Ramtron.
> Unfortunately the chip sends the Device ID in reversed order, so the
> continuation code is not at the beginning, but instead at the end. Even
> more unfortunate is that when reading further the chip sends more 7f
> codes which means we are not even able to count the continuation codes.
> We can only hope that this reversed Device ID will never match any other
> devices ID.
> 
> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Collisions are improbable as of now, the solution from above is good
enough. In case of future collisions one can introduce an INFO9 macro,
with the downsize that struct flash_info would grow and we have lots of
flashes. A more elegant solution would be to introduce dedicated
flash ID tables for each bank in JESP106BA.

Amended commit description with the above text and applied. Thanks.


______________________________________________________
Linux MTD discussion mailing list
http://lists.infradead.org/mailman/listinfo/linux-mtd/

  parent reply	other threads:[~2020-05-28  8:12 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-04-24  6:56 [PATCH v3] mtd: spi-nor: Add support for Cypress cy15x104q Sascha Hauer
2020-05-12  9:47 ` Sascha Hauer
2020-05-28  8:12 ` Tudor.Ambarus [this message]
2020-11-05 18:54   ` Tim Harvey
2020-11-09 15:01     ` Vignesh Raghavendra

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=13199742.Uhtxi0mpr9@192.168.0.120 \
    --to=tudor.ambarus@microchip.com \
    --cc=kernel@pengutronix.de \
    --cc=linux-mtd@lists.infradead.org \
    --cc=miquel.raynal@bootlin.com \
    --cc=richard@nod.at \
    --cc=s.hauer@pengutronix.de \
    --cc=vigneshr@ti.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: 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).