[RFC/PATCH 1/3] NAND multiple plane feature

[RFC/PATCH 1/3] NAND multiple plane feature

[Alexey Korolev]

Hi,
This patch provides identification of planes number on NAND device.
According to NAND datasheets the 5th byte of id contains info about
number of planes.

Thanks,
Alexey


Signed-off-by: Vasiliy Leonenko <vasiliy.leonenko@mail.ru>
Signed-off-by: Alexey Korolev <akorolev@infradead.org>
--------
 drivers/mtd/nand/nand_base.c |    5 +++++
 include/linux/mtd/nand.h     |    2 ++
 2 files changed, 7 insertions(+)

diff -Nurp linux-2.6.24.3/drivers/mtd/nand/nand_base.c linux-2.6.24.3-dp/drivers/mtd/nand/nand_base.c
--- linux-2.6.24.3/drivers/mtd/nand/nand_base.c	2008-02-26 03:20:20.000000000 +0300
+++ linux-2.6.24.3-dp/drivers/mtd/nand/nand_base.c	2008-05-28 02:06:01.000000000 +0400
@@ -2259,10 +2367,15 @@ static struct nand_flash_dev *nand_get_f
 	/* Newer devices have all the information in additional id bytes */
 	if (!type->pagesize) {
 		int extid;
+		int planeid;
 		/* The 3rd id byte holds MLC / multichip data */
 		chip->cellinfo = chip->read_byte(mtd);
 		/* The 4th id byte is the important one */
 		extid = chip->read_byte(mtd);
+		/* The 5th id byte contains number of planes */
+		planeid = chip->read_byte(mtd);
+		/* Number of planes*/
+		chip->numplanes = 1 << ((planeid >> 2) & 0x03);
 		/* Calc pagesize */
 		mtd->writesize = 1024 << (extid & 0x3);
 		extid >>= 2;
diff -Nurp linux-2.6.24.3/include/linux/mtd/nand.h linux-2.6.24.3-dp/include/linux/mtd/nand.h
--- linux-2.6.24.3/include/linux/mtd/nand.h	2008-02-26 03:20:20.000000000 +0300
+++ linux-2.6.24.3-dp/include/linux/mtd/nand.h	2008-05-28 02:11:51.000000000 +0400
@@ -343,6 +344,7 @@ struct nand_buffers {
  * @options:		[BOARDSPECIFIC] various chip options. They can partly be set to inform nand_scan about
  *			special functionality. See the defines for further explanation
  * @badblockpos:	[INTERN] position of the bad block marker in the oob area
+ * @numplanes:		[INTERN] number of ident planes on NAND device
  * @cellinfo:		[INTERN] MLC/multichip data from chip ident
  * @numchips:		[INTERN] number of physical chips
  * @chipsize:		[INTERN] the size of one chip for multichip arrays
@@ -399,6 +400,7 @@ struct nand_chip {
 	int		subpagesize;
 	uint8_t		cellinfo;
 	int		badblockpos;
+	int		numplanes;
 
 	nand_state_t	state;
 

Re: [RFC/PATCH 1/3] NAND multiple plane feature

[Jörn Engel]

On Wed, 28 May 2008 13:41:46 +0100, Alexey Korolev wrote:
> diff -Nurp linux-2.6.24.3/drivers/mtd/nand/nand_base.c linux-2.6.24.3-dp/drivers/mtd/nand/nand_base.c
> --- linux-2.6.24.3/drivers/mtd/nand/nand_base.c	2008-02-26 03:20:20.000000000 +0300
> +++ linux-2.6.24.3-dp/drivers/mtd/nand/nand_base.c	2008-05-28 02:06:01.000000000 +0400
> @@ -2259,10 +2367,15 @@ static struct nand_flash_dev *nand_get_f
>  	/* Newer devices have all the information in additional id bytes */
>  	if (!type->pagesize) {
>  		int extid;
> +		int planeid;
>  		/* The 3rd id byte holds MLC / multichip data */
>  		chip->cellinfo = chip->read_byte(mtd);
>  		/* The 4th id byte is the important one */
>  		extid = chip->read_byte(mtd);
> +		/* The 5th id byte contains number of planes */
> +		planeid = chip->read_byte(mtd);
> +		/* Number of planes*/

This comment seems redundant.  And it fooled me for a few seconds.
Remove it?

> +		chip->numplanes = 1 << ((planeid >> 2) & 0x03);
>  		/* Calc pagesize */
>  		mtd->writesize = 1024 << (extid & 0x3);
>  		extid >>= 2;

Jörn

-- 
Fools ignore complexity.  Pragmatists suffer it.
Some can avoid it.  Geniuses remove it.
-- Perlis's Programming Proverb #58, SIGPLAN Notices, Sept.  1982

Re: [RFC/PATCH 1/3] NAND multiple plane feature

[Alexey Korolev]

[-- Attachment #1: Type: TEXT/PLAIN, Size: 250 bytes --]

Hi Jörn

Thank you very much for patches review. 

> > +		planeid = chip->read_byte(mtd);
> > +		/* Number of planes*/
> 
> This comment seems redundant.  And it fooled me for a few seconds.
> Remove it?

No problem. Will be removed.

Thanks,
Alexey