diff mbox

[v9,1/9] mtd: nand: omap: combine different flavours of 1-bit hamming ecc schemes

Message ID 1381816197-20477-2-git-send-email-pekon@ti.com (mailing list archive)
State New, archived
Headers show

Commit Message

pekon gupta Oct. 15, 2013, 5:49 a.m. UTC
OMAP NAND driver currently supports multiple flavours of 1-bit Hamming
ecc-scheme, like:
- OMAP_ECC_HAMMING_CODE_DEFAULT
	1-bit hamming ecc code using software library
- OMAP_ECC_HAMMING_CODE_HW
	1-bit hamming ecc-code using GPMC h/w engine
- OMAP_ECC_HAMMING_CODE_HW_ROMCODE
	1-bit hamming ecc-code using GPMC h/w engin with ecc-layout compatible
	to ROM code.

This patch combines above multiple ecc-schemes into single implementation:
- OMAP_ECC_HAM1_CODE_HW
	1-bit hamming ecc-code using GPMC h/w engine with ROM-code compatible
	ecc-layout.

Signed-off-by: Pekon Gupta <pekon@ti.com>
Reviewed-by: Felipe Balbi <balbi@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
---
 Documentation/devicetree/bindings/mtd/gpmc-nand.txt | 8 ++++----
 arch/arm/mach-omap2/board-flash.c                   | 2 +-
 arch/arm/mach-omap2/gpmc.c                          | 4 +---
 drivers/mtd/nand/omap2.c                            | 9 +++------
 include/linux/platform_data/mtd-nand-omap2.h        | 6 +-----
 5 files changed, 10 insertions(+), 19 deletions(-)

Comments

Mark Rutland Oct. 18, 2013, 10:59 a.m. UTC | #1
Hi Pekon,

On Tue, Oct 15, 2013 at 06:49:49AM +0100, Pekon Gupta wrote:
> OMAP NAND driver currently supports multiple flavours of 1-bit Hamming
> ecc-scheme, like:
> - OMAP_ECC_HAMMING_CODE_DEFAULT
> 	1-bit hamming ecc code using software library
> - OMAP_ECC_HAMMING_CODE_HW
> 	1-bit hamming ecc-code using GPMC h/w engine
> - OMAP_ECC_HAMMING_CODE_HW_ROMCODE
> 	1-bit hamming ecc-code using GPMC h/w engin with ecc-layout compatible
> 	to ROM code.
> 
> This patch combines above multiple ecc-schemes into single implementation:
> - OMAP_ECC_HAM1_CODE_HW
> 	1-bit hamming ecc-code using GPMC h/w engine with ROM-code compatible
> 	ecc-layout.
> 
> Signed-off-by: Pekon Gupta <pekon@ti.com>
> Reviewed-by: Felipe Balbi <balbi@ti.com>
> Acked-by: Tony Lindgren <tony@atomide.com>
> ---
>  Documentation/devicetree/bindings/mtd/gpmc-nand.txt | 8 ++++----
>  arch/arm/mach-omap2/board-flash.c                   | 2 +-
>  arch/arm/mach-omap2/gpmc.c                          | 4 +---
>  drivers/mtd/nand/omap2.c                            | 9 +++------
>  include/linux/platform_data/mtd-nand-omap2.h        | 6 +-----
>  5 files changed, 10 insertions(+), 19 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/mtd/gpmc-nand.txt b/Documentation/devicetree/bindings/mtd/gpmc-nand.txt
> index df338cb..25ee232 100644
> --- a/Documentation/devicetree/bindings/mtd/gpmc-nand.txt
> +++ b/Documentation/devicetree/bindings/mtd/gpmc-nand.txt
> @@ -22,10 +22,10 @@ Optional properties:
>  				width of 8 is assumed.
>  
>   - ti,nand-ecc-opt:		A string setting the ECC layout to use. One of:
> -
> -		"sw"		Software method (default)
> -		"hw"		Hardware method
> -		"hw-romcode"	gpmc hamming mode method & romcode layout
> +		"sw"		<deprecated> use "ham1" instead
> +		"hw"		<deprecated> use "ham1" instead
> +		"hw-romcode"	<deprecated> use "ham1" instead
> +		"ham1"		1-bit Hamming ecc code
>  		"bch4"		4-bit BCH ecc code
>  		"bch8"		8-bit BCH ecc code

[...]

> diff --git a/arch/arm/mach-omap2/gpmc.c b/arch/arm/mach-omap2/gpmc.c
> index 579697a..c9fb353 100644
> --- a/arch/arm/mach-omap2/gpmc.c
> +++ b/arch/arm/mach-omap2/gpmc.c
> @@ -1342,9 +1342,7 @@ static void __maybe_unused gpmc_read_timings_dt(struct device_node *np,
>  #ifdef CONFIG_MTD_NAND
>  
>  static const char * const nand_ecc_opts[] = {
> -	[OMAP_ECC_HAMMING_CODE_DEFAULT]		= "sw",
> -	[OMAP_ECC_HAMMING_CODE_HW]		= "hw",
> -	[OMAP_ECC_HAMMING_CODE_HW_ROMCODE]	= "hw-romcode",
> +	[OMAP_ECC_HAM1_CODE_HW]			= "ham1",
>  	[OMAP_ECC_BCH4_CODE_HW]			= "bch4",
>  	[OMAP_ECC_BCH8_CODE_HW]			= "bch8",
>  };

As the parsing isn't updated until the next patch, doesn't this
temporarily break DTBs with the deprecated ti,nand-ecc-opt values?

Thanks,
Mark.
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pekon gupta Oct. 18, 2013, 11:48 a.m. UTC | #2
Hi Mark,

> From: Mark Rutland
> [...]
> 
> > diff --git a/arch/arm/mach-omap2/gpmc.c b/arch/arm/mach-
> omap2/gpmc.c
> > index 579697a..c9fb353 100644
> > --- a/arch/arm/mach-omap2/gpmc.c
> > +++ b/arch/arm/mach-omap2/gpmc.c
> > @@ -1342,9 +1342,7 @@ static void __maybe_unused
> gpmc_read_timings_dt(struct device_node *np,
> >  #ifdef CONFIG_MTD_NAND
> >
> >  static const char * const nand_ecc_opts[] = {
> > -	[OMAP_ECC_HAMMING_CODE_DEFAULT]		= "sw",
> > -	[OMAP_ECC_HAMMING_CODE_HW]		= "hw",
> > -	[OMAP_ECC_HAMMING_CODE_HW_ROMCODE]	= "hw-
> romcode",
> > +	[OMAP_ECC_HAM1_CODE_HW]			= "ham1",
> >  	[OMAP_ECC_BCH4_CODE_HW]			= "bch4",
> >  	[OMAP_ECC_BCH8_CODE_HW]			= "bch8",
> >  };
> 
> As the parsing isn't updated until the next patch, doesn't this
> temporarily break DTBs with the deprecated ti,nand-ecc-opt values?
> 
Ok then I'll swap the [Patch 1/9] and [Patch 2/9] so that DT parsing updates
(with backward compatibility) happen before the deprecation of DT values.
This way old DT binding would work all through.

And as DT parsing is kept backward compatible, so .dts changes would not
break the DTBs even if updated in separate patch.

with regards, pekon
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diff mbox

Patch

diff --git a/Documentation/devicetree/bindings/mtd/gpmc-nand.txt b/Documentation/devicetree/bindings/mtd/gpmc-nand.txt
index df338cb..25ee232 100644
--- a/Documentation/devicetree/bindings/mtd/gpmc-nand.txt
+++ b/Documentation/devicetree/bindings/mtd/gpmc-nand.txt
@@ -22,10 +22,10 @@  Optional properties:
 				width of 8 is assumed.
 
  - ti,nand-ecc-opt:		A string setting the ECC layout to use. One of:
-
-		"sw"		Software method (default)
-		"hw"		Hardware method
-		"hw-romcode"	gpmc hamming mode method & romcode layout
+		"sw"		<deprecated> use "ham1" instead
+		"hw"		<deprecated> use "ham1" instead
+		"hw-romcode"	<deprecated> use "ham1" instead
+		"ham1"		1-bit Hamming ecc code
 		"bch4"		4-bit BCH ecc code
 		"bch8"		8-bit BCH ecc code
 
diff --git a/arch/arm/mach-omap2/board-flash.c b/arch/arm/mach-omap2/board-flash.c
index fc20a61..ac82512 100644
--- a/arch/arm/mach-omap2/board-flash.c
+++ b/arch/arm/mach-omap2/board-flash.c
@@ -142,7 +142,7 @@  __init board_nand_init(struct mtd_partition *nand_parts, u8 nr_parts, u8 cs,
 	board_nand_data.nr_parts	= nr_parts;
 	board_nand_data.devsize		= nand_type;
 
-	board_nand_data.ecc_opt = OMAP_ECC_HAMMING_CODE_DEFAULT;
+	board_nand_data.ecc_opt = OMAP_ECC_BCH8_CODE_HW;
 	gpmc_nand_init(&board_nand_data, gpmc_t);
 }
 #endif /* CONFIG_MTD_NAND_OMAP2 || CONFIG_MTD_NAND_OMAP2_MODULE */
diff --git a/arch/arm/mach-omap2/gpmc.c b/arch/arm/mach-omap2/gpmc.c
index 579697a..c9fb353 100644
--- a/arch/arm/mach-omap2/gpmc.c
+++ b/arch/arm/mach-omap2/gpmc.c
@@ -1342,9 +1342,7 @@  static void __maybe_unused gpmc_read_timings_dt(struct device_node *np,
 #ifdef CONFIG_MTD_NAND
 
 static const char * const nand_ecc_opts[] = {
-	[OMAP_ECC_HAMMING_CODE_DEFAULT]		= "sw",
-	[OMAP_ECC_HAMMING_CODE_HW]		= "hw",
-	[OMAP_ECC_HAMMING_CODE_HW_ROMCODE]	= "hw-romcode",
+	[OMAP_ECC_HAM1_CODE_HW]			= "ham1",
 	[OMAP_ECC_BCH4_CODE_HW]			= "bch4",
 	[OMAP_ECC_BCH8_CODE_HW]			= "bch8",
 };
diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c
index 4ecf0e5..8d521aa 100644
--- a/drivers/mtd/nand/omap2.c
+++ b/drivers/mtd/nand/omap2.c
@@ -1993,10 +1993,7 @@  static int omap_nand_probe(struct platform_device *pdev)
 	}
 
 	/* select the ecc type */
-	if (pdata->ecc_opt == OMAP_ECC_HAMMING_CODE_DEFAULT)
-		info->nand.ecc.mode = NAND_ECC_SOFT;
-	else if ((pdata->ecc_opt == OMAP_ECC_HAMMING_CODE_HW) ||
-		(pdata->ecc_opt == OMAP_ECC_HAMMING_CODE_HW_ROMCODE)) {
+	if (pdata->ecc_opt == OMAP_ECC_HAM1_CODE_HW) {
 		info->nand.ecc.bytes            = 3;
 		info->nand.ecc.size             = 512;
 		info->nand.ecc.strength         = 1;
@@ -2025,7 +2022,7 @@  static int omap_nand_probe(struct platform_device *pdev)
 	}
 
 	/* rom code layout */
-	if (pdata->ecc_opt == OMAP_ECC_HAMMING_CODE_HW_ROMCODE) {
+	if (pdata->ecc_opt == OMAP_ECC_HAM1_CODE_HW) {
 
 		if (info->nand.options & NAND_BUSWIDTH_16)
 			offset = 2;
@@ -2033,7 +2030,7 @@  static int omap_nand_probe(struct platform_device *pdev)
 			offset = 1;
 			info->nand.badblock_pattern = &bb_descrip_flashbased;
 		}
-		omap_oobinfo.eccbytes = 3 * (info->mtd.oobsize/16);
+		omap_oobinfo.eccbytes = 3 * (info->mtd.writesize / 512);
 		for (i = 0; i < omap_oobinfo.eccbytes; i++)
 			omap_oobinfo.eccpos[i] = i+offset;
 
diff --git a/include/linux/platform_data/mtd-nand-omap2.h b/include/linux/platform_data/mtd-nand-omap2.h
index 6bf9ef4..cb5a54a 100644
--- a/include/linux/platform_data/mtd-nand-omap2.h
+++ b/include/linux/platform_data/mtd-nand-omap2.h
@@ -23,11 +23,7 @@  enum nand_io {
 };
 
 enum omap_ecc {
-		/* 1-bit ecc: stored at end of spare area */
-	OMAP_ECC_HAMMING_CODE_DEFAULT = 0, /* Default, s/w method */
-	OMAP_ECC_HAMMING_CODE_HW, /* gpmc to detect the error */
-		/* 1-bit ecc: stored at beginning of spare area as romcode */
-	OMAP_ECC_HAMMING_CODE_HW_ROMCODE, /* gpmc method & romcode layout */
+	OMAP_ECC_HAM1_CODE_HW = 0, /* 1-bit Hamming ecc code */
 	OMAP_ECC_BCH4_CODE_HW, /* 4-bit BCH ecc code */
 	OMAP_ECC_BCH8_CODE_HW, /* 8-bit BCH ecc code */
 };