10  * The MLC NAND flash controller provides hardware Reed-Solomon ECC
12  * of-band data must be written together in order to have a valid ECC.
15  * blank (all-ones) out-of-band data and a valid ECC, and any later
16  * out-of-band data write will void the ECC.
19  * should not rely on the ECC validity.
92  * OOB data in each small page are 6 'free' then 10 ECC bytes.
95  * while the the four ECC bytes are groupe in its last 40 bytes.
97  * The struct below represents how free vs ecc oob bytes are stored
109 	} ecc[4];  member
183  * @mode:	mode to set the ECC HW to.
194  * ECC layout -- this is needed whatever ECC mode we are using.
197  * front and R/S ECC at the back.
217  * lpc32xx_read_page_hwecc - read in- and out-of-band data with ECC
229  * ECC will be false if out-of-band data has been updated since in-band
264 		/* copy last 10 bytes (R/S ECC) at back of OOB buffer */  in lpc32xx_read_page_hwecc()
265 		memcpy(&oob->ecc[i], lpc32xx_nand_mlc_registers->buff, 10);  in lpc32xx_read_page_hwecc()
271  * lpc32xx_read_page_raw - read raw (in-band, out-of-band and ECC) data
278  * Read NAND directly; can read pages with invalid ECC.
306 		/* copy last 10 bytes (R/S ECC) at back of OOB buffer */  in lpc32xx_read_page_raw()
307 		memcpy(&oob->ecc[i], lpc32xx_nand_mlc_registers->data, 10);  in lpc32xx_read_page_raw()
323  * ECC covers in- and out-of-band data and was written when out-of-band
325  * blank, then the ECC will be false and the read will return bitflips,
326  * even in case of ECC failure where we will return 5 bitflips. The
364 		/* copy next 10 bytes (R/S ECC) at back of OOB buffer */  in lpc32xx_read_oob()
365 		memcpy(&oob->ecc[i], lpc32xx_nand_mlc_registers->buff, 10);  in lpc32xx_read_oob()
371  * lpc32xx_write_page_hwecc - write in- and out-of-band data with ECC
396 		/* copy next 6 bytes from OOB buffer -- excluding ECC */  in lpc32xx_write_page_hwecc()
398 		/* wait for ECC to return to ready state */  in lpc32xx_write_page_hwecc()
405 		/* if ECC stalled, return failure */  in lpc32xx_write_page_hwecc()
425  * lpc32xx_write_page_raw - write raw (in-band, out-of-band and ECC) data
438  * ECC area. Therefore, it can write pages with valid *or* invalid ECC.
452 		/* copy next 6 bytes into OOB buffer -- excluding ECC */  in lpc32xx_write_page_raw()
454 		/* copy next 10 bytes into OOB buffer -- that is 'ECC' */  in lpc32xx_write_page_raw()
455 		memcpy(lpc32xx_nand_mlc_registers->buff, &oob->ecc[i], 10);  in lpc32xx_write_page_raw()
466  * Since ECC covers in- and out-of-band data, writing out-of-band data
467  * with ECC will render the page ECC wrong -- or, if the page was blank,
468  * then it will produce a good ECC but a later in-band data write will
471  * Therefore, do not compute or write any ECC, and always return success.
473  * This implies that we do four writes, since non-ECC out-of-band data
487 		/* copy 6 non-ECC out-of-band bytes directly into NAND */  in lpc32xx_write_oob()
561 	/* Set needed ECC fields */  in board_nand_init()
563 	lpc32xx_chip.ecc.mode = NAND_ECC_HW;  in board_nand_init()
564 	lpc32xx_chip.ecc.layout = &lpc32xx_largepage_ecclayout;  in board_nand_init()
565 	lpc32xx_chip.ecc.size = 512;  in board_nand_init()
566 	lpc32xx_chip.ecc.bytes = 10;  in board_nand_init()
567 	lpc32xx_chip.ecc.strength = 4;  in board_nand_init()
568 	lpc32xx_chip.ecc.read_page = lpc32xx_read_page_hwecc;  in board_nand_init()
569 	lpc32xx_chip.ecc.read_page_raw = lpc32xx_read_page_raw;  in board_nand_init()
570 	lpc32xx_chip.ecc.write_page = lpc32xx_write_page_hwecc;  in board_nand_init()
571 	lpc32xx_chip.ecc.write_page_raw = lpc32xx_write_page_raw;  in board_nand_init()
572 	lpc32xx_chip.ecc.read_oob = lpc32xx_read_oob;  in board_nand_init()
573 	lpc32xx_chip.ecc.write_oob = lpc32xx_write_oob;  in board_nand_init()