mtd: nand: omap: combine different flavours of 1-bit hamming ecc schemes

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>
Tested-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

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
 

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 */

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;
@@ -2025,15 +2022,15 @@ 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;
  else {
  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;
 

include/linux/platform_data/mtd-nand-omap2.h

@@ -23,13 +23,8 @@ 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 */
  /* 1-bit ECC calculation by GPMC, Error detection by Software */
- OMAP_ECC_HAM1_CODE_HW,
+ OMAP_ECC_HAM1_CODE_HW = 0,
  /* 4-bit ECC calculation by GPMC, Error detection by Software */
  OMAP_ECC_BCH4_CODE_HW_DETECTION_SW,
  /* 4-bit ECC calculation by GPMC, Error detection by ELM */