mtd: nand: davinci: add opportunity to write keystone U-boot image

The Keystone SoCs use the same NAND driver as Davinci.
This patch adds opportunity to write Keystone U-boot image to NAND
device using appropriate RBL ECC layout. This is needed only if RBL
boots U-boot from NAND device and that's supposed that raw u-boot
partition is used only for writing image.

The main problem is that default Davinci ECC layout is different from
Keystone RBL layout. To read U-boot image the RBL needs that image was
written using RBL ECC layout.

The BBT table is written using default Davinci layout and has to
be updated using one. The BBT can be updated only while erasing
chip or by forced bad block assigning, so erase function has to
use native ecc layout in order to be able to write BBT correctly.
So if we're writing to NAND U-boot address we use RBL layout for
others we use default ECC layout.

Also remove definition for CONFIG_CMD_NAND_ECCLAYOUT as there is no
reasons to use ECC layout commands. It was added by mistake.

Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@ti.com>

2 files changed, 199 insertions, 1 deletions

diff --git a/drivers/mtd/nand/davinci_nand.c b/drivers/mtd/nand/davinci_nand.c
index 5d42509..a079b1e 100644
--- a/drivers/mtd/nand/davinci_nand.c
+++ b/drivers/mtd/nand/davinci_nand.c
@@ -305,6 +305,189 @@ static struct nand_ecclayout nand_davinci_4bit_layout_oobfirst = {
 #endif
 };
 
+#if defined CONFIG_KEYSTONE_RBL_NAND
+#if defined(CONFIG_SYS_NAND_PAGE_2K)
+static struct nand_ecclayout nand_keystone_rbl_4bit_layout_oobfirst = {
+	.eccbytes = 40,
+	.eccpos = {
+		6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
+		22, 23, 24, 25, 26, 27, 28, 29, 30, 31,
+		38, 39, 40, 41, 42, 43, 44, 45, 46, 47,
+		54, 55, 56, 57, 58, 59, 60, 61, 62, 63,
+	},
+	.oobfree = {
+		{.offset = 2, .length = 4, },
+		{.offset = 16, .length = 6, },
+		{.offset = 32, .length = 6, },
+		{.offset = 48, .length = 6, },
+	},
+#elif defined(CONFIG_SYS_NAND_PAGE_4K)
+	.eccbytes = 80,
+	.eccpos = {
+		6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
+		22, 23, 24, 25, 26, 27, 28, 29, 30, 31,
+		38, 39, 40, 41, 42, 43, 44, 45, 46, 47,
+		54, 55, 56, 57, 58, 59, 60, 61, 62, 63,
+		70, 71, 72, 73, 74, 75, 76, 77, 78, 79,
+		86, 87, 88, 89, 90, 91, 92, 93, 94, 95,
+		102, 103, 104, 105, 106, 107, 108, 109, 110, 111,
+		118, 119, 120, 121, 122, 123, 124, 125, 126, 127,
+	},
+	.oobfree = {
+		{.offset = 2, .length = 4, },
+		{.offset = 16, .length = 6, },
+		{.offset = 32, .length = 6, },
+		{.offset = 48, .length = 6, },
+		{.offset = 64, .length = 6, },
+		{.offset = 80, .length = 6, },
+		{.offset = 96, .length = 6, },
+		{.offset = 112, .length = 6, },
+	},
+#endif
+};
+
+#ifdef CONFIG_SYS_NAND_PAGE_2K
+#define CONFIG_KEYSTONE_NAND_MAX_RBL_PAGE	CONFIG_KEYSTONE_NAND_MAX_RBL_SIZE >> 11
+#elif defined(CONFIG_SYS_NAND_PAGE_4K)
+#define CONFIG_KEYSTONE_NAND_MAX_RBL_PAGE	CONFIG_KEYSTONE_NAND_MAX_RBL_SIZE >> 12
+#endif
+
+/**
+ * nand_davinci_write_page - write one page
+ * @mtd: MTD device structure
+ * @chip: NAND chip descriptor
+ * @buf: the data to write
+ * @oob_required: must write chip->oob_poi to OOB
+ * @page: page number to write
+ * @cached: cached programming
+ * @raw: use _raw version of write_page
+ */
+static int nand_davinci_write_page(struct mtd_info *mtd, struct nand_chip *chip,
+				   const uint8_t *buf, int oob_required,
+				   int page, int cached, int raw)
+{
+	int status;
+	int ret = 0;
+	struct nand_ecclayout *saved_ecc_layout;
+
+	/* save current ECC layout and assign Keystone RBL ECC layout */
+	if (page < CONFIG_KEYSTONE_NAND_MAX_RBL_PAGE) {
+		saved_ecc_layout = chip->ecc.layout;
+		chip->ecc.layout = &nand_keystone_rbl_4bit_layout_oobfirst;
+		mtd->oobavail = chip->ecc.layout->oobavail;
+	}
+
+	chip->cmdfunc(mtd, NAND_CMD_SEQIN, 0x00, page);
+
+	if (unlikely(raw))
+		status = chip->ecc.write_page_raw(mtd, chip, buf, oob_required);
+	else
+		status = chip->ecc.write_page(mtd, chip, buf, oob_required);
+
+	if (status < 0) {
+		ret = status;
+		goto err;
+	}
+
+	chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
+	status = chip->waitfunc(mtd, chip);
+
+	/*
+	 * See if operation failed and additional status checks are
+	 * available.
+	 */
+	if ((status & NAND_STATUS_FAIL) && (chip->errstat))
+		status = chip->errstat(mtd, chip, FL_WRITING, status, page);
+
+	if (status & NAND_STATUS_FAIL) {
+		ret = -EIO;
+		goto err;
+	}
+
+#ifdef CONFIG_MTD_NAND_VERIFY_WRITE
+	/* Send command to read back the data */
+	chip->cmdfunc(mtd, NAND_CMD_READ0, 0, page);
+
+	if (chip->verify_buf(mtd, buf, mtd->writesize)) {
+		ret = -EIO;
+		goto err;
+	}
+
+	/* Make sure the next page prog is preceded by a status read */
+	chip->cmdfunc(mtd, NAND_CMD_STATUS, -1, -1);
+#endif
+err:
+	/* restore ECC layout */
+	if (page < CONFIG_KEYSTONE_NAND_MAX_RBL_PAGE) {
+		chip->ecc.layout = saved_ecc_layout;
+		mtd->oobavail = saved_ecc_layout->oobavail;
+	}
+
+	return ret;
+}
+
+/**
+ * nand_davinci_read_page_hwecc - hardware ECC based page read function
+ * @mtd: mtd info structure
+ * @chip: nand chip info structure
+ * @buf: buffer to store read data
+ * @oob_required: caller requires OOB data read to chip->oob_poi
+ * @page: page number to read
+ *
+ * Not for syndrome calculating ECC controllers which need a special oob layout.
+ */
+static int nand_davinci_read_page_hwecc(struct mtd_info *mtd, struct nand_chip *chip,
+				uint8_t *buf, int oob_required, int page)
+{
+	int i, eccsize = chip->ecc.size;
+	int eccbytes = chip->ecc.bytes;
+	int eccsteps = chip->ecc.steps;
+	uint32_t *eccpos;
+	uint8_t *p = buf;
+	uint8_t *ecc_code = chip->buffers->ecccode;
+	uint8_t *ecc_calc = chip->buffers->ecccalc;
+	struct nand_ecclayout *saved_ecc_layout = chip->ecc.layout;
+
+	/* save current ECC layout and assign Keystone RBL ECC layout */
+	if (page < CONFIG_KEYSTONE_NAND_MAX_RBL_PAGE) {
+		chip->ecc.layout = &nand_keystone_rbl_4bit_layout_oobfirst;
+		mtd->oobavail = chip->ecc.layout->oobavail;
+	}
+
+	eccpos = chip->ecc.layout->eccpos;
+
+	/* Read the OOB area first */
+	chip->cmdfunc(mtd, NAND_CMD_READOOB, 0, page);
+	chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
+	chip->cmdfunc(mtd, NAND_CMD_READ0, 0, page);
+
+	for (i = 0; i < chip->ecc.total; i++)
+		ecc_code[i] = chip->oob_poi[eccpos[i]];
+
+	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
+		int stat;
+
+		chip->ecc.hwctl(mtd, NAND_ECC_READ);
+		chip->read_buf(mtd, p, eccsize);
+		chip->ecc.calculate(mtd, p, &ecc_calc[i]);
+
+		stat = chip->ecc.correct(mtd, p, &ecc_code[i], NULL);
+		if (stat < 0)
+			mtd->ecc_stats.failed++;
+		else
+			mtd->ecc_stats.corrected += stat;
+	}
+
+	/* restore ECC layout */
+	if (page < CONFIG_KEYSTONE_NAND_MAX_RBL_PAGE) {
+		chip->ecc.layout = saved_ecc_layout;
+		mtd->oobavail = saved_ecc_layout->oobavail;
+	}
+
+	return 0;
+}
+#endif /* CONFIG_KEYSTONE_RBL_NAND */
+
 static void nand_davinci_4bit_enable_hwecc(struct mtd_info *mtd, int mode)
 {
 	u32 val;
@@ -604,6 +787,19 @@ static void nand_flash_init(void)
 
 void davinci_nand_init(struct nand_chip *nand)
 {
+#if defined CONFIG_KEYSTONE_RBL_NAND
+	int i;
+	struct nand_ecclayout *layout;
+
+	layout = &nand_keystone_rbl_4bit_layout_oobfirst;
+	layout->oobavail = 0;
+	for (i = 0; layout->oobfree[i].length &&
+	     i < ARRAY_SIZE(layout->oobfree); i++)
+		layout->oobavail += layout->oobfree[i].length;
+
+	nand->write_page = nand_davinci_write_page;
+	nand->ecc.read_page = nand_davinci_read_page_hwecc;
+#endif
 	nand->chip_delay  = 0;
 #ifdef CONFIG_SYS_NAND_USE_FLASH_BBT
 	nand->bbt_options	  |= NAND_BBT_USE_FLASH;
diff --git a/include/configs/k2hk_evm.h b/include/configs/k2hk_evm.h
index 858329f..3f87741 100644
--- a/include/configs/k2hk_evm.h
+++ b/include/configs/k2hk_evm.h
@@ -135,7 +135,8 @@
 
 /* NAND Configuration */
 #define CONFIG_NAND_DAVINCI
-#define CONFIG_CMD_NAND_ECCLAYOUT
+#define CONFIG_KEYSTONE_RBL_NAND
+#define CONFIG_KEYSTONE_NAND_MAX_RBL_SIZE	CONFIG_ENV_OFFSET
 #define CONFIG_SYS_NAND_CS                     2
 #define CONFIG_SYS_NAND_USE_FLASH_BBT
 #define CONFIG_SYS_NAND_4BIT_HW_ECC_OOBFIRST
@@ -155,6 +156,7 @@
 #define CONFIG_MTD_DEVICE
 #define CONFIG_RBTREE
 #define CONFIG_LZO
+#define MTDIDS_DEFAULT			"nand0=davinci_nand.0"
 #define MTDPARTS_DEFAULT                "mtdparts=davinci_nand.0:" \
 					"1024k(bootloader)ro,512k(params)ro," \
 					"-(ubifs)"