From: Wolfgang Denk <wd@denx.de>
To: u-boot@lists.denx.de
Subject: [U-Boot-Users] [patch] add support for "eeprom info"
Date: Thu, 24 Jan 2008 12:31:36 +0100 [thread overview]
Message-ID: <20080124113136.8DADF24788@gemini.denx.de> (raw)
In-Reply-To: Your message of "Thu, 24 Jan 2008 04:13:03 EST." <200801240413.04318.vapier@gentoo.org>
In message <200801240413.04318.vapier@gentoo.org> you wrote:
>
> > I think you are doing something wrong when you try to use "eeprom" to
> > access "SPI flash" - these are differnt entities...
>
> let's make sure we're talking about the same thing. SPI flashes are eeproms
> that have a SPI interface. so Spansion's S25FLxxxx, ST's m25pxtmels
> AT45DBxxxx, Winbond's W25Xxx/W25Pxx, and such. they need to be erased before
> writing, are split up into some unit size, etc... all SPI flashes nowadays
> conform to the JEDEC standard (JEP106) which allows for querying of
> manufacturer/device ids so that they can be dynamically detected. sounds to
> me like "eeprom" is the correct interface for utilizing these devices.
Sounds to me as if you were talking about flash devices with a SPI bus
interface.
The original SPI eeprom support was implemented som 7+ years ago for
the Siemens CCM board; this is where the "CONFIG_SPI" stuff in
common/cmd_eeprom.c comes from, and this was supported by the
cpu/mpc8xx/spi.c SPI driver. Note that this was a real EEPROM device,
i. e. we just needed spi_read() and spi_write() functions to access
it. No erase, no sectors or any such stuff.
That was an EEPROM - what you have looks like a flash device to me.
Best regards,
Wolfgang Denk
--
DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
In the pitiful, multipage, connection-boxed form to which the flow-
chart has today been elaborated, it has proved to be useless as a
design tool -- programmers draw flowcharts after, not before, writing
the programs they describe. - Fred Brooks, Jr.
next prev parent reply other threads:[~2008-01-24 11:31 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-01-23 16:13 [U-Boot-Users] [patch] add support for "eeprom info" Mike Frysinger
2008-01-23 21:06 ` Wolfgang Denk
2008-01-23 21:15 ` Mike Frysinger
2008-01-23 21:23 ` Wolfgang Denk
2008-01-23 22:29 ` Mike Frysinger
2008-01-24 0:44 ` Wolfgang Denk
2008-01-24 3:39 ` Mike Frysinger
2008-01-24 4:24 ` Ben Warren
2008-01-24 5:17 ` Mike Frysinger
2008-01-24 11:13 ` Wolfgang Denk
2008-01-25 13:31 ` Mike Frysinger
2008-01-24 9:13 ` Mike Frysinger
2008-01-24 11:31 ` Wolfgang Denk [this message]
2008-01-25 13:33 ` Mike Frysinger
2008-01-25 15:09 ` Wolfgang Denk
2008-01-25 16:02 ` Mike Frysinger
2008-01-25 16:54 ` J. William Campbell
2008-01-25 17:21 ` Mike Frysinger
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=20080124113136.8DADF24788@gemini.denx.de \
--to=wd@denx.de \
--cc=u-boot@lists.denx.de \
/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