[U-Boot] [PATCH v4 09/11] S3C24XX: Add NAND Flash driver

José Miguel Gonçalves
2012-09-19T11:25:25Z

NAND Flash driver with HW ECC for the S3C24XX SoCs.
Currently it only supports SLC NAND chips.

Signed-off-by: Jos? Miguel Gon?alves <jose.goncalves@inov.pt>
---
Changes for v2:
- Coding style cleanup
- Use of clrsetbits_le32()
- Use of register bit macros instead of magic numbers

Changes for v3:
- Removed magic numbers
- Removed a macro to declare a void printf()
- Replaced one printf() with a puts()

Changes for v4:
- Coding style cleanup
- Use of a struct to store chip private data
- Replaced u_long by u32
- Replaced u_char by uint8_t
- Added error message in s3c_nand_select_chip()
- Optimization of s3c_nand_hwcontrol()
---
drivers/mtd/nand/Makefile | 1 +
drivers/mtd/nand/s3c24xx_nand.c | 255 +++++++++++++++++++++++++++++++++++++++
2 files changed, 256 insertions(+)
create mode 100644 drivers/mtd/nand/s3c24xx_nand.c

diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
index 29dc20e..791ec44 100644
--- a/drivers/mtd/nand/Makefile
+++ b/drivers/mtd/nand/Makefile
@@ -60,6 +60,7 @@ COBJS-$(CONFIG_NAND_MXS) += mxs_nand.o
COBJS-$(CONFIG_NAND_NDFC) += ndfc.o
COBJS-$(CONFIG_NAND_NOMADIK) += nomadik.o
COBJS-$(CONFIG_NAND_S3C2410) += s3c2410_nand.o
+COBJS-$(CONFIG_NAND_S3C24XX) += s3c24xx_nand.o
COBJS-$(CONFIG_NAND_S3C64XX) += s3c64xx.o
COBJS-$(CONFIG_NAND_SPEAR) += spr_nand.o
COBJS-$(CONFIG_NAND_OMAP_GPMC) += omap_gpmc.o
diff --git a/drivers/mtd/nand/s3c24xx_nand.c b/drivers/mtd/nand/s3c24xx_nand.c
new file mode 100644
index 0000000..384ffbf
--- /dev/null
+++ b/drivers/mtd/nand/s3c24xx_nand.c
@@ -0,0 +1,255 @@
+/*
+ * (C) Copyright 2012 INOV - INESC Inovacao
+ * Jose Goncalves <jose.goncalves@inov.pt>
+ *
+ * Based on drivers/mtd/nand/s3c64xx.c and U-Boot 1.3.4 from Samsung.
+ * Supports only SLC NAND Flash chips.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <nand.h>
+#include <asm/io.h>
+#include <asm/errno.h>
+#include <asm/arch/s3c24xx_cpu.h>
+
+#define TACLS_VAL 7 /* CLE & ALE duration setting (0~7) */
+#define TWRPH0_VAL 7 /* TWRPH0 duration setting (0~7) */
+#define TWRPH1_VAL 7 /* TWRPH1 duration setting (0~7) */
+
+#define MAX_CHIPS 2
+
+/* Struct to store NAND chip private data */
+struct s3c_chip_info {
+ int cs;
+};
+
+static void s3c_nand_select_chip(struct mtd_info *mtd, int chip)
+{
+ struct s3c24xx_nand *const nand = s3c24xx_get_base_nand();
+ u32 nfcont;
+
+ nfcont = readl(&nand->nfcont);
+
+ switch (chip) {
+ case -1:
+ nfcont |= NFCONT_NCE1 | NFCONT_NCE0;
+ break;
+ case 0:
+ nfcont &= ~NFCONT_NCE0;
+ break;
+ case 1:
+ nfcont &= ~NFCONT_NCE1;
+ break;
+ default:
+ printf("S3C24XX NAND: Invalid chip select (%d).\n", chip);
+ return;
+ }
+
+ writel(nfcont, &nand->nfcont);
+}
+
+/*
+ * Hardware specific access to control-lines function
+ */
+static void s3c_nand_hwcontrol(struct mtd_info *mtd, int cmd, unsigned int ctrl)
+{
+ struct s3c24xx_nand *const nand = s3c24xx_get_base_nand();
+ struct nand_chip *this;
+ const struct s3c_chip_info *info;
+
+ if (ctrl & NAND_CTRL_CHANGE) {
+ if (ctrl & NAND_NCE) {
+ this = mtd->priv;
+ info = this->priv;
+ s3c_nand_select_chip(mtd, info->cs);
+ } else {
+ s3c_nand_select_chip(mtd, -1);
+ }
+ }
+
+ if (cmd == NAND_CMD_NONE)
+ return;
+
+ if (ctrl & NAND_CLE)
+ writeb(cmd, &nand->nfcmmd);
+ else
+ writeb(cmd, &nand->nfaddr);
+}
+
+/*
+ * Function for checking device ready pin
+ */
+static int s3c_nand_device_ready(struct mtd_info *mtdinfo)
+{
+ struct s3c24xx_nand *const nand = s3c24xx_get_base_nand();
+
+ return readl(&nand->nfstat) & NFSTAT_RNB;
+}
+
+#ifdef CONFIG_S3C24XX_NAND_HWECC
+/*
+ * This function is called before encoding ECC codes to ready ECC engine.
+ */
+static void s3c_nand_enable_hwecc(struct mtd_info *mtd, int mode)
+{
+ struct s3c24xx_nand *const nand = s3c24xx_get_base_nand();
+
+ /* Set 1-bit ECC */
+ clrsetbits_le32(&nand->nfconf, NFCONF_ECCTYPE_MASK,
+ NFCONF_ECCTYPE_1BIT);
+
+ /* Initialize & unlock ECC */
+ clrsetbits_le32(&nand->nfcont, NFCONT_MECCLOCK, NFCONT_INITMECC);
+}
+
+/*
+ * This function is called immediately after encoding ECC codes.
+ * This function returns encoded ECC codes.
+ */
+static int s3c_nand_calculate_ecc(struct mtd_info *mtd, const uint8_t *dat,
+ uint8_t *ecc_code)
+{
+ struct s3c24xx_nand *const nand = s3c24xx_get_base_nand();
+ u32 nfmecc0;
+
+ /* Lock ECC */
+ setbits_le32(&nand->nfcont, NFCONT_MECCLOCK);
+
+ /* Return 1-bit ECC */
+ nfmecc0 = readl(&nand->nfmecc[0]);
+
+ ecc_code[0] = nfmecc0 & 0xff;
+ ecc_code[1] = (nfmecc0 >> 8) & 0xff;
+ ecc_code[2] = (nfmecc0 >> 16) & 0xff;
+ ecc_code[3] = (nfmecc0 >> 24) & 0xff;
+
+ return 0;
+}
+
+/*
+ * This function determines whether read data is good or not.
+ * On SLC, must write ECC codes to controller before reading status bit.
+ * If status bit is good, return 0.
+ * If a correctable error occured, correct it and return 1.
+ * If an uncorrectable error occured, return -1.
+ */
+static int s3c_nand_correct_data(struct mtd_info *mtd, uint8_t *dat,
+ uint8_t *read_ecc, uint8_t *calc_ecc)
+{
+ struct s3c24xx_nand *const nand = s3c24xx_get_base_nand();
+ int ret;
+ u32 nfeccerr0, nfmeccdata0, nfmeccdata1, err_byte_addr;
+ uint8_t err_type, repaired;
+
+ /* SLC: Write ECC to compare */
+ nfmeccdata0 = (((u32) read_ecc[1]) << 16) | read_ecc[0];
+ nfmeccdata1 = (((u32) read_ecc[3]) << 16) | read_ecc[2];
+ writel(nfmeccdata0, &nand->nfmeccd[0]);
+ writel(nfmeccdata1, &nand->nfmeccd[1]);
+
+ /* Read ECC status */
+ nfeccerr0 = readl(&nand->nfeccerr[0]);
+ err_type = nfeccerr0 & 0x3;
+
+ switch (err_type) {
+ case 0: /* No error */
+ ret = 0;
+ break;
+
+ case 1:
+ /*
+ * 1 bit error (Correctable)
+ * (nfeccerr0 >> 7) & 0x7ff :error byte number
+ * (nfeccerr0 >> 4) & 0x7 :error bit number
+ */
+ err_byte_addr = (nfeccerr0 >> 7) & 0x7ff;
+ repaired = dat[err_byte_addr] ^ (1 << ((nfeccerr0 >> 4) & 0x7));
+
+ printf("S3C24XX NAND: 1 bit error detected at byte %u. "
+ "Correcting from 0x%02x to 0x%02x\n",
+ err_byte_addr, dat[err_byte_addr], repaired);
+
+ dat[err_byte_addr] = repaired;
+
+ ret = 1;
+ break;
+
+ case 2: /* Multiple error */
+ case 3: /* ECC area error */
+ puts("S3C24XX NAND: ECC uncorrectable error detected.\n");
+ ret = -1;
+ break;
+ }
+
+ return ret;
+}
+#endif /* CONFIG_S3C24XX_NAND_HWECC */
+
+/*
+ * Board-specific NAND initialization.
+ */
+int board_nand_init(struct nand_chip *nand)
+{
+ static const struct s3c_chip_info chip_info[MAX_CHIPS] = { {0}, {1} };
+ static int chip_n;
+ struct s3c24xx_nand *const nand_reg = s3c24xx_get_base_nand();
+
+ if (chip_n == 0) {
+ /* Extend NAND timings to the maximum */
+ clrsetbits_le32(&nand_reg->nfconf,
+ NFCONF_TACLS_MASK | NFCONF_TWRPH0_MASK |
+ NFCONF_TWRPH1_MASK,
+ NFCONF_TACLS(TACLS_VAL) |
+ NFCONF_TWRPH0(TWRPH0_VAL) |
+ NFCONF_TWRPH1(TWRPH1_VAL));
+
+ /* Disable chip selects and soft lock, enable controller */
+ clrsetbits_le32(&nand_reg->nfcont, NFCONT_WP,
+ NFCONT_NCE1 | NFCONT_NCE0 | NFCONT_ENABLE);
+ } else if (chip_n >= MAX_CHIPS) {
+ return -ENODEV;
+ }
+
+ nand->IO_ADDR_R = &nand_reg->nfdata;
+ nand->IO_ADDR_W = &nand_reg->nfdata;
+ nand->cmd_ctrl = s3c_nand_hwcontrol;
+ nand->dev_ready = s3c_nand_device_ready;
+ nand->select_chip = s3c_nand_select_chip;
+ nand->options = 0;
+#ifdef CONFIG_SPL_BUILD
+ nand->read_buf = nand_read_buf;
+#endif
+
+#ifdef CONFIG_S3C24XX_NAND_HWECC
+ nand->ecc.hwctl = s3c_nand_enable_hwecc;
+ nand->ecc.calculate = s3c_nand_calculate_ecc;
+ nand->ecc.correct = s3c_nand_correct_data;
+ nand->ecc.mode = NAND_ECC_HW_OOB_FIRST;
+ nand->ecc.size = CONFIG_SYS_NAND_ECCSIZE;
+ nand->ecc.bytes = CONFIG_SYS_NAND_ECCBYTES;
+#else
+ nand->ecc.mode = NAND_ECC_SOFT;
+#endif /* ! CONFIG_S3C24XX_NAND_HWECC */
+
+ nand->priv = (void *)&chip_info[chip_n++];
+
+ return 0;
+}
--
1.7.9.5