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

[Stefano Babic <sbabic@denx.de>]

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

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