From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gerhard Sittig Subject: =?UTF-8?q?=5BPATCH=20v1=202/2=5D=20mtd=3A=20nand=3A=20gpio=3A=20improve=20comments=20about=20GPIO=20assisted=20operation?= Date: Tue, 5 Aug 2014 10:37:26 +0200 Message-ID: <1407227846-3257-2-git-send-email-gsi@denx.de> References: <1407227846-3257-1-git-send-email-gsi@denx.de> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <1407227846-3257-1-git-send-email-gsi-ynQEQJNshbs@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Jamie Iles , linux-mtd-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, Mike Rapoport , Alexander Shiyan Cc: Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , David Woodhouse , Brian Norris , Gerhard Sittig List-Id: devicetree@vger.kernel.org The drivers/mtd/nand/gpio.c driver does not GPIO bitbang the complete NAND protocol, but instead is GPIO _assisted_ -- a memory mapped interf= ace communicates commands and data, and only few control signals are connec= ted 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 --- 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. =20 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. =20 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 @@ * * =C2=A9 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 si= gnals + * (the DT binding refers to this as "GPIO assisted NAND flash") * * This program is free software; you can redistribute it and/or modif= y * it under the terms of the GNU General Public License version 2 as --=20 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe devicetree" i= n the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html