Re: [U-Boot] [PATCH v3 3/4] mtd: nand: add Freescale vf610_nfc driver

Hi Stefan,

patch is landed on my desk as part of i.MX. I will have some minor points. Is thi

On 18/08/2014 18:26, Stefan Agner wrote:

This adds initial support for Freescale NFC (NAND Flash Controller) found in ARM Vybrid SoC's, Power Architecture MPC5125 and others. The driver is called vf610_nfc since this is the first supported and tested hardware platform supported by the driver.

Signed-off-by: Stefan Agner stefan@agner.ch

[snip]

+struct vf610_nfc {

• struct mtd_info *mtd;
• struct nand_chip chip;

+/* struct device *dev;*/

Do not add dead code. Check this globally.

• void __iomem *regs;
• uint column;
• int spareonly;
• int page;
• /* Status and ID are in alternate locations. */
• int alt_buf;

+#define ALT_BUF_ID 1 +#define ALT_BUF_STAT 2

• struct clk *clk;

+};

+#define mtd_to_nfc(_mtd) (struct vf610_nfc *)((struct nand_chip *)_mtd->priv)->priv;

+static u8 bbt_pattern[] = {'B', 'b', 't', '0' }; +static u8 mirror_pattern[] = {'1', 't', 'b', 'B' };

+static struct nand_bbt_descr bbt_main_descr = {

• .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE |

•    NAND_BBT_2BIT | NAND_BBT_VERSION,
  

• .offs = 11,
• .len = 4,
• .veroffs = 15,
• .maxblocks = 4,
• .pattern = bbt_pattern,

+};

+static struct nand_bbt_descr bbt_mirror_descr = {

• .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE |

•    NAND_BBT_2BIT | NAND_BBT_VERSION,
  

• .offs = 11,
• .len = 4,
• .veroffs = 15,
• .maxblocks = 4,
• .pattern = mirror_pattern,

+};

+static struct nand_ecclayout vf610_nfc_ecc45 = {

• .eccbytes = 45,
• .eccpos = {19, 20, 21, 22, 23,

•    24, 25, 26, 27, 28, 29, 30, 31,
  

•    32, 33, 34, 35, 36, 37, 38, 39,
  

•    40, 41, 42, 43, 44, 45, 46, 47,
  

•    48, 49, 50, 51, 52, 53, 54, 55,
  

•    56, 57, 58, 59, 60, 61, 62, 63},
  

• .oobfree = {

• {.offset = 8,
  

•  .length = 11} }
  

+};

+static inline u32 vf610_nfc_read(struct mtd_info *mtd, uint reg) +{

• struct vf610_nfc *nfc = mtd_to_nfc(mtd);
• return readl(nfc->regs + reg);

+}

+static inline void vf610_nfc_write(struct mtd_info *mtd, uint reg, u32 val) +{

• struct vf610_nfc *nfc = mtd_to_nfc(mtd);
• writel(val, nfc->regs + reg);

+}

+static inline void vf610_nfc_set(struct mtd_info *mtd, uint reg, u32 bits) +{

• vf610_nfc_write(mtd, reg, vf610_nfc_read(mtd, reg) | bits);

+}

+static inline void vf610_nfc_clear(struct mtd_info *mtd, uint reg, u32 bits) +{

• vf610_nfc_write(mtd, reg, vf610_nfc_read(mtd, reg) & ~bits);

+}

+static inline void vf610_nfc_set_field(struct mtd_info *mtd, u32 reg,

• 		       u32 mask, u32 shift, u32 val)
  

+{

• vf610_nfc_write(mtd, reg,

• 	(vf610_nfc_read(mtd, reg) & (~mask)) | val << shift);
  

+}

+/* Clear flags for upcoming command */ +static inline void vf610_nfc_clear_status(void __iomem *regbase) +{

• void __iomem *reg = regbase + NFC_IRQ_STATUS;
• u32 tmp = __raw_readl(reg);
• tmp |= CMD_DONE_CLEAR_BIT | IDLE_CLEAR_BIT;
• __raw_writel(tmp, reg);

+}

+/* Wait for complete operation */ +static inline void vf610_nfc_done(struct mtd_info *mtd) +{

• struct vf610_nfc *nfc = mtd_to_nfc(mtd);
• uint start;
• /*

• * Barrier is needed after this write. This write need
  

• * to be done before reading the next register the first
  

• * time.
  

• * vf610_nfc_set implicates such a barrier by using writel
  

• * to write to the register.
  

• */
  

• vf610_nfc_set(mtd, NFC_FLASH_CMD2, START_BIT);
• start = get_timer(0);
• while (!(vf610_nfc_read(mtd, NFC_IRQ_STATUS) & IDLE_IRQ_BIT)) {

• if (get_timer(start) > NFC_TIMEOUT) {
  

• 	printf("Timeout while waiting for !BUSY.\n");
  

• 	return;
  

• }
  

• }
• vf610_nfc_clear_status(nfc->regs);

+}

+static u8 vf610_nfc_get_id(struct mtd_info *mtd, int col) +{

• u32 flash_id;
• if (col < 4) {

• flash_id = vf610_nfc_read(mtd, NFC_FLASH_STATUS1);
  

• return (flash_id >> (3-col)*8) & 0xff;
  

• } else {

• flash_id = vf610_nfc_read(mtd, NFC_FLASH_STATUS2);
  

• return flash_id >> 24;
  

• }

+}

+static u8 vf610_nfc_get_status(struct mtd_info *mtd) +{

• return vf610_nfc_read(mtd, NFC_FLASH_STATUS2) & STATUS_BYTE1_MASK;

+}

+/* Single command */ +static void vf610_nfc_send_command(void __iomem *regbase, u32 cmd_byte1,

• 		   u32 cmd_code)
  

+{

• void __iomem *reg = regbase + NFC_FLASH_CMD2;
• u32 tmp;
• vf610_nfc_clear_status(regbase);
• tmp = __raw_readl(reg);
• tmp &= ~(CMD_BYTE1_MASK | CMD_CODE_MASK | BUFNO_MASK);
• tmp |= cmd_byte1 << CMD_BYTE1_SHIFT;
• tmp |= cmd_code << CMD_CODE_SHIFT;
• __raw_writel(tmp, reg);

+}

+/* Two commands */ +static void vf610_nfc_send_commands(void __iomem *regbase, u32 cmd_byte1,

• 	      u32 cmd_byte2, u32 cmd_code)
  

+{

• void __iomem *reg = regbase + NFC_FLASH_CMD1;
• u32 tmp;
• vf610_nfc_send_command(regbase, cmd_byte1, cmd_code);
• tmp = __raw_readl(reg);
• tmp &= ~CMD_BYTE2_MASK;
• tmp |= cmd_byte2 << CMD_BYTE2_SHIFT;
• __raw_writel(tmp, reg);

+}

+static void vf610_nfc_addr_cycle(struct mtd_info *mtd, int column, int page) +{

• if (column != -1) {

• struct vf610_nfc *nfc = mtd_to_nfc(mtd);
  

• if (nfc->chip.options | NAND_BUSWIDTH_16)
  

• 	column = column/2;
  

• vf610_nfc_set_field(mtd, NFC_COL_ADDR, COL_ADDR_MASK,
  

• 	      COL_ADDR_SHIFT, column);
  

• }
• if (page != -1)

• vf610_nfc_set_field(mtd, NFC_ROW_ADDR, ROW_ADDR_MASK,
  

• 		ROW_ADDR_SHIFT, page);
  

+}

+/* Send command to NAND chip */ +static void vf610_nfc_command(struct mtd_info *mtd, unsigned command,

• 	      int column, int page)
  

+{

• struct vf610_nfc *nfc = mtd_to_nfc(mtd);
• nfc->column = max(column, 0);
• nfc->spareonly = 0;
• nfc->alt_buf = 0;
• switch (command) {
• case NAND_CMD_PAGEPROG:

• nfc->page = -1;
  

• vf610_nfc_send_commands(nfc->regs, NAND_CMD_SEQIN,
  

• 	     command, PROGRAM_PAGE_CMD_CODE);
  

• vf610_nfc_addr_cycle(mtd, column, page);
  

• break;
  

• case NAND_CMD_RESET:

• vf610_nfc_send_command(nfc->regs, command, RESET_CMD_CODE);
  

• break;
  

• /*

• * NFC does not support sub-page reads and writes,
  

• * so emulate them using full page transfers.
  

• */
  

• case NAND_CMD_READOOB:

• nfc->spareonly = 1;
  

• case NAND_CMD_SEQIN: /* Pre-read for partial writes. */
• case NAND_CMD_READ0:

• column = 0;
  

• /* Already read? */
  

• if (nfc->page == page)
  

• 	return;
  

• nfc->page = page;
  

• vf610_nfc_send_commands(nfc->regs, NAND_CMD_READ0,
  

• 		  NAND_CMD_READSTART, READ_PAGE_CMD_CODE);
  

• vf610_nfc_addr_cycle(mtd, column, page);
  

• break;
  

• case NAND_CMD_ERASE1:

• if (nfc->page == page)
  

• 	nfc->page = -1;
  

• vf610_nfc_send_commands(nfc->regs, command,
  

• 		  NAND_CMD_ERASE2, ERASE_CMD_CODE);
  

• vf610_nfc_addr_cycle(mtd, column, page);
  

• break;
  

• case NAND_CMD_READID:

• nfc->alt_buf = ALT_BUF_ID;
  

• vf610_nfc_send_command(nfc->regs, command, READ_ID_CMD_CODE);
  

• break;
  

• case NAND_CMD_STATUS:

• nfc->alt_buf = ALT_BUF_STAT;
  

• vf610_nfc_send_command(nfc->regs, command, STATUS_READ_CMD_CODE);
  

• break;
  

• default:

• return;
  

• }
• vf610_nfc_done(mtd);

+}

+static inline void vf610_nfc_read_spare(struct mtd_info *mtd, void *buf,

• 			int len)
  

+{

• struct vf610_nfc *nfc = mtd_to_nfc(mtd);
• len = min(mtd->oobsize, (uint)len);
• if (len > 0)

• memcpy(buf, nfc->regs + mtd->writesize, len);
  

+}

+/* Read data from NFC buffers */ +static void vf610_nfc_read_buf(struct mtd_info *mtd, u_char *buf, int len) +{

• struct vf610_nfc *nfc = mtd_to_nfc(mtd);
• uint c = nfc->column;
• uint l;
• /* Handle main area */
• if (!nfc->spareonly) {

• l = min((uint)len, mtd->writesize - c);
  

• nfc->column += l;
  

• if (!nfc->alt_buf)
  

• 	memcpy(buf, nfc->regs + NFC_MAIN_AREA(0) + c, l);
  

• else
  

• 	if (nfc->alt_buf & ALT_BUF_ID)
  

• 		*buf = vf610_nfc_get_id(mtd, c);
  

• 	else
  

• 		*buf = vf610_nfc_get_status(mtd);
  

• buf += l;
  

• len -= l;
  

• }
• /* Handle spare area access */
• if (len) {

• nfc->column += len;
  

• vf610_nfc_read_spare(mtd, buf, len);
  

• }

+}

+/* Write data to NFC buffers */ +static void vf610_nfc_write_buf(struct mtd_info *mtd, const u_char *buf,

• 		int len)
  

+{

• struct vf610_nfc *nfc = mtd_to_nfc(mtd);
• uint c = nfc->column;
• uint l;
• l = min((uint)len, mtd->writesize + mtd->oobsize - c);
• nfc->column += l;
• memcpy(nfc->regs + NFC_MAIN_AREA(0) + c, buf, l);

+}

+/* Read byte from NFC buffers */ +static u8 vf610_nfc_read_byte(struct mtd_info *mtd) +{

• u8 tmp;
• vf610_nfc_read_buf(mtd, &tmp, sizeof(tmp));
• return tmp;

+}

+/* Read word from NFC buffers */ +static u16 vf610_nfc_read_word(struct mtd_info *mtd) +{

• u16 tmp;
• vf610_nfc_read_buf(mtd, (u_char *)&tmp, sizeof(tmp));
• return tmp;

+}

+/* If not provided, upper layers apply a fixed delay. */ +static int vf610_nfc_dev_ready(struct mtd_info *mtd) +{

• /* NFC handles R/B internally; always ready. */
• return 1;

+}

+/*

• • This function supports Vybrid only (MPC5125 would have full RB and four CS)
• */

+static void vf610_nfc_select_chip(struct mtd_info *mtd, int chip) +{ +#ifdef CONFIG_VF610

• u32 tmp = vf610_nfc_read(mtd, NFC_ROW_ADDR);
• tmp &= ~(ROW_ADDR_CHIP_SEL_RB_MASK | ROW_ADDR_CHIP_SEL_MASK);
• tmp |= 1 << ROW_ADDR_CHIP_SEL_RB_SHIFT;
• if (chip == 0)

• tmp |= 1 << ROW_ADDR_CHIP_SEL_SHIFT;
  

• else if (chip == 1)

• tmp |= 2 << ROW_ADDR_CHIP_SEL_SHIFT;
  

• vf610_nfc_write(mtd, NFC_ROW_ADDR, tmp);

+#endif +}

+/* Count the number of 0's in buff upto max_bits */ +static inline int count_written_bits(uint8_t *buff, int size, int max_bits) +{

• uint32_t *buff32 = (uint32_t *)buff;
• int k, written_bits = 0;
• for (k = 0; k < (size / 4); k++) {

• written_bits += hweight32(~buff32[k]);
  

• if (written_bits > max_bits)
  

• 	break;
  

• }
• return written_bits;

+}

+static inline int vf610_nfc_correct_data(struct mtd_info *mtd, u_char *dat) +{

• struct vf610_nfc *nfc = mtd_to_nfc(mtd);
• u8 ecc_status;
• u8 ecc_count;
• int flip;
• ecc_status = __raw_readb(nfc->regs + ECC_SRAM_ADDR * 8 + ECC_OFFSET);
• ecc_count = ecc_status & ECC_ERR_COUNT;
• if (!(ecc_status & ECC_STATUS_MASK))

• return ecc_count;
  

• /* If 'ecc_count' zero or less then buffer is all 0xff or erased. */
• flip = count_written_bits(dat, nfc->chip.ecc.size, ecc_count);
• /* ECC failed. */
• if (flip > ecc_count) {

• nfc->page = -1;
  

• return -1;
  

• }
• /* Erased page. */
• memset(dat, 0xff, nfc->chip.ecc.size);
• return 0;

+}

+static int vf610_nfc_read_page(struct mtd_info *mtd, struct nand_chip *chip,

• 		uint8_t *buf, int oob_required, int page)
  

+{

• int eccsize = chip->ecc.size;
• int stat;
• uint8_t *p = buf;
• vf610_nfc_read_buf(mtd, p, eccsize);
• if (oob_required)

• vf610_nfc_read_buf(mtd, chip->oob_poi, mtd->oobsize);
  

• stat = vf610_nfc_correct_data(mtd, p);
• if (stat < 0)

• mtd->ecc_stats.failed++;
  

• else

• mtd->ecc_stats.corrected += stat;
  

• return 0;

+}

+/*

• • ECC will be calculated automatically
• */

+static int vf610_nfc_write_page(struct mtd_info *mtd, struct nand_chip *chip,

• 	       const uint8_t *buf, int oob_required)
  

+{

• vf610_nfc_write_buf(mtd, buf, mtd->writesize);
• if (oob_required)

• vf610_nfc_write_buf(mtd, chip->oob_poi, mtd->oobsize);
  

• return 0;

+}

+struct vf610_nfc_config {

• int hardware_ecc;
• int width;
• int flash_bbt;

+};

+static int vf610_nfc_nand_init(int devnum, void __iomem *addr) +{

• struct mtd_info *mtd = &nand_info[devnum];
• struct nand_chip *chip;
• struct vf610_nfc *nfc;
• int err = 0;
• int page_sz;
• struct vf610_nfc_config cfg = {

• .hardware_ecc = 1,
  

+#ifdef CONFIG_SYS_NAND_BUSWIDTH_16BIT

• .width = 16,
  

+#else

• .width = 8,
  

+#endif

• .flash_bbt = 1,
  

• };
• nfc = malloc(sizeof(*nfc));
• if (!nfc) {

• printf(KERN_ERR "%s: Memory exhausted!\n", __func__);
  

• return -ENOMEM;
  

• }
• chip = &nfc->chip;
• nfc->regs = addr;
• mtd->priv = chip;
• chip->priv = nfc;
• if (cfg.width == 16) {

• chip->options |= NAND_BUSWIDTH_16;
  

• vf610_nfc_set(mtd, NFC_FLASH_CONFIG, CONFIG_16BIT);
  

• } else {

• chip->options &= ~NAND_BUSWIDTH_16;
  

• vf610_nfc_clear(mtd, NFC_FLASH_CONFIG, CONFIG_16BIT);
  

• }
• chip->dev_ready = vf610_nfc_dev_ready;
• chip->cmdfunc = vf610_nfc_command;
• chip->read_byte = vf610_nfc_read_byte;
• chip->read_word = vf610_nfc_read_word;
• chip->read_buf = vf610_nfc_read_buf;
• chip->write_buf = vf610_nfc_write_buf;
• chip->select_chip = vf610_nfc_select_chip;
• /* Bad block options. */
• if (cfg.flash_bbt)

• chip->bbt_options = NAND_BBT_USE_FLASH | NAND_BBT_CREATE;
  

• /* Default to software ECC until flash ID. */
• vf610_nfc_set_field(mtd, NFC_FLASH_CONFIG,

•       CONFIG_ECC_MODE_MASK,
  

•       CONFIG_ECC_MODE_SHIFT, ECC_BYPASS);
  

• chip->bbt_td = &bbt_main_descr;
• chip->bbt_md = &bbt_mirror_descr;
• page_sz = PAGE_2K + OOB_64;
• page_sz += cfg.width == 16 ? 1 : 0;
• vf610_nfc_write(mtd, NFC_SECTOR_SIZE, page_sz);
• /* Set configuration register. */
• vf610_nfc_clear(mtd, NFC_FLASH_CONFIG, CONFIG_ADDR_AUTO_INCR_BIT);
• vf610_nfc_clear(mtd, NFC_FLASH_CONFIG, CONFIG_BUFNO_AUTO_INCR_BIT);
• vf610_nfc_clear(mtd, NFC_FLASH_CONFIG, CONFIG_BOOT_MODE_BIT);
• vf610_nfc_clear(mtd, NFC_FLASH_CONFIG, CONFIG_DMA_REQ_BIT);
• vf610_nfc_set(mtd, NFC_FLASH_CONFIG, CONFIG_FAST_FLASH_BIT);
• /* Enable Idle IRQ */
• vf610_nfc_set(mtd, NFC_IRQ_STATUS, IDLE_EN_BIT);
• /* PAGE_CNT = 1 */
• vf610_nfc_set_field(mtd, NFC_FLASH_CONFIG, CONFIG_PAGE_CNT_MASK,

• 	CONFIG_PAGE_CNT_SHIFT, 1);
  

• /* Set ECC_STATUS offset */
• vf610_nfc_set_field(mtd, NFC_FLASH_CONFIG,

•       CONFIG_ECC_SRAM_ADDR_MASK,
  

•       CONFIG_ECC_SRAM_ADDR_SHIFT, ECC_SRAM_ADDR);
  

• /* first scan to find the device and get the page size */
• if (nand_scan_ident(mtd, CONFIG_SYS_MAX_NAND_DEVICE, NULL)) {

• err = -ENXIO;
  

• goto error;
  

• }
• chip->ecc.mode = NAND_ECC_SOFT; /* default */
• page_sz = mtd->writesize + mtd->oobsize;
• /* Single buffer only, max 256 OOB minus ECC status */
• if (page_sz > PAGE_2K + 256 - 8) {

• dev_err(nfc->dev, "Unsupported flash size\n");
  

• err = -ENXIO;
  

• goto error;
  

• }
• page_sz += cfg.width == 16 ? 1 : 0;
• vf610_nfc_write(mtd, NFC_SECTOR_SIZE, page_sz);
• if (cfg.hardware_ecc) {

• if (mtd->writesize != PAGE_2K && mtd->oobsize < 64) {
  

• 	dev_err(nfc->dev, "Unsupported flash with hwecc\n");
  

• 	err = -ENXIO;
  

• 	goto error;
  

• }
  

• chip->ecc.layout = &vf610_nfc_ecc45;
  

• /* propagate ecc.layout to mtd_info */
  

• mtd->ecclayout = chip->ecc.layout;
  

• chip->ecc.read_page = vf610_nfc_read_page;
  

• chip->ecc.write_page = vf610_nfc_write_page;
  

• chip->ecc.mode = NAND_ECC_HW;
  

• chip->ecc.bytes = 45;
  

• chip->ecc.size = PAGE_2K;
  

• chip->ecc.strength = 24;
  

• /* set ECC mode to 45 bytes OOB with 24 bits correction */
  

• vf610_nfc_set_field(mtd, NFC_FLASH_CONFIG,
  

• 		CONFIG_ECC_MODE_MASK,
  

• 		CONFIG_ECC_MODE_SHIFT, ECC_45_BYTE);
  

• /* Enable ECC_STATUS */
  

• vf610_nfc_set(mtd, NFC_FLASH_CONFIG, CONFIG_ECC_SRAM_REQ_BIT);
  

• }
• /* second phase scan */
• err = nand_scan_tail(mtd);
• if (err)

• return err;
  

• err = nand_register(devnum);
• if (err)

• return err;
  

• return 0;

+error:

• return err;

+}

+void board_nand_init(void) +{

• int err = vf610_nfc_nand_init(0, (void __iomem *)CONFIG_SYS_NAND_BASE);
• if (err)

• printf("VF610 NAND init failed (err %d)\n", err);
  

+}

I propose you add the accessors functions as suggested by Bill, and I will take care of this patch (and 4/4 as well) for merging in the release.

Thanks, Stefano