devicetree.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Gerhard Sittig <gsi-ynQEQJNshbs@public.gmane.org>
To: devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	Jamie Iles <jamie-wmLquQDDieKakBO8gow8eQ@public.gmane.org>,
	linux-mtd-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org,
	Mike Rapoport <mike-UTxiZqZC01RS1MOuV/RT9w@public.gmane.org>,
	Alexander Shiyan <shc_work-JGs/UdohzUI@public.gmane.org>
Cc: Rob Herring <robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
	Pawel Moll <pawel.moll-5wv7dgnIgG8@public.gmane.org>,
	Mark Rutland <mark.rutland-5wv7dgnIgG8@public.gmane.org>,
	Ian Campbell
	<ijc+devicetree-KcIKpvwj1kUDXYZnReoRVg@public.gmane.org>,
	Kumar Gala <galak-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>,
	David Woodhouse <dwmw2-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>,
	Brian Norris
	<computersforpeace-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>,
	Gerhard Sittig <gsi-ynQEQJNshbs@public.gmane.org>
Subject: [PATCH v1 2/2] mtd: nand: gpio: improve comments about GPIO assisted operation
Date: Tue,  5 Aug 2014 10:37:26 +0200	[thread overview]
Message-ID: <1407227846-3257-2-git-send-email-gsi@denx.de> (raw)
In-Reply-To: <1407227846-3257-1-git-send-email-gsi-ynQEQJNshbs@public.gmane.org>

The drivers/mtd/nand/gpio.c driver does not GPIO bitbang the complete
NAND protocol, but instead is GPIO _assisted_ -- a memory mapped interface
communicates commands and data, and only few control signals are connected
to GPIO pins.

Expand comments in the driver source and in the Kconfig description to
better reflect the very nature of the driver.  The previous text could be
mistaken for complete GPIO bitbanging.

Signed-off-by: Gerhard Sittig <gsi-ynQEQJNshbs@public.gmane.org>
---
 drivers/mtd/nand/Kconfig |    6 ++++--
 drivers/mtd/nand/gpio.c  |    4 +++-
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
index f1cf503517fd..0ef8b35b459f 100644
--- a/drivers/mtd/nand/Kconfig
+++ b/drivers/mtd/nand/Kconfig
@@ -75,10 +75,12 @@ config MTD_NAND_DENALI_SCRATCH_REG_ADDR
           boards, the scratch register is at 0xFF108018.
 
 config MTD_NAND_GPIO
-	tristate "GPIO NAND Flash driver"
+	tristate "GPIO assisted NAND Flash driver"
 	depends on GPIOLIB
 	help
-	  This enables a GPIO based NAND flash driver.
+	  This enables a NAND flash driver where control signals are
+	  connected to GPIO pins, and commands and data are communicated
+	  via a memory mapped interface.
 
 config MTD_NAND_AMS_DELTA
 	tristate "NAND Flash device on Amstrad E3"
diff --git a/drivers/mtd/nand/gpio.c b/drivers/mtd/nand/gpio.c
index 117ce333fdd4..226eda6f2eee 100644
--- a/drivers/mtd/nand/gpio.c
+++ b/drivers/mtd/nand/gpio.c
@@ -8,7 +8,9 @@
  *
  * © 2004 Simtec Electronics
  *
- * Device driver for NAND connected via GPIO
+ * Device driver for NAND flash that uses a memory mapped interface to
+ * read/write the NAND commands and data, and GPIO pins for control signals
+ * (the DT binding refers to this as "GPIO assisted NAND flash")
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
-- 
1.7.10.4

--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

  parent reply	other threads:[~2014-08-05  8:37 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-08-05  8:37 [PATCH v1 1/2] devicetree: bindings: improve description for GPIO assisted NAND flash Gerhard Sittig
     [not found] ` <1407227846-3257-1-git-send-email-gsi-ynQEQJNshbs@public.gmane.org>
2014-08-05  8:37   ` Gerhard Sittig [this message]
2014-11-05  7:56   ` Brian Norris

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=1407227846-3257-2-git-send-email-gsi@denx.de \
    --to=gsi-ynqeqjnshbs@public.gmane.org \
    --cc=computersforpeace-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org \
    --cc=devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
    --cc=dwmw2-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org \
    --cc=galak-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org \
    --cc=ijc+devicetree-KcIKpvwj1kUDXYZnReoRVg@public.gmane.org \
    --cc=jamie-wmLquQDDieKakBO8gow8eQ@public.gmane.org \
    --cc=linux-mtd-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org \
    --cc=mark.rutland-5wv7dgnIgG8@public.gmane.org \
    --cc=mike-UTxiZqZC01RS1MOuV/RT9w@public.gmane.org \
    --cc=pawel.moll-5wv7dgnIgG8@public.gmane.org \
    --cc=robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org \
    --cc=shc_work-JGs/UdohzUI@public.gmane.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).