Re: [PATCH v4 10/11] mtd: nand: stm_nand_bch: add support for ST's BCH NAND controller

[Brian Norris]

+ others

OK, let's take another crack at this...

I have a few smaller requests that I would otherwise patch on top of
this, but after looking a little closer, I'm still pretty sure there are
several things broken, particularly in your bank/chip-select handling.

So for a TL;DR, let's the get the following two agreed and fixed for a v5:

 1. multi chip-select / bank handling - either do it right, or check to make
 sure the DT only has a single bank (more comments below)

 2. bitflips in erased pages - I'm inclined to take your patch as long
 as we put in the word 'FIXME' or 'TODO' (I have some comments on your
 current wording below), and you agree to update to Boris's work once
 it's ready:

   http://lists.infradead.org/pipermail/linux-mtd/2014-December/056749.html

I think most of the rest is less important.

On Wed, Nov 05, 2014 at 04:59:52PM +0000, Lee Jones wrote:
> Reviewed-by: Pekon Gupta <pekon@xxxxxxxxxxx>
> Signed-off-by: Lee Jones <lee.jones@xxxxxxxxxx>
> ---
>  drivers/mtd/nand/Kconfig        |    7 +
>  drivers/mtd/nand/Makefile       |    1 +
>  drivers/mtd/nand/stm_nand_bch.c | 1645 +++++++++++++++++++++++++++++++++++++++
>  include/linux/mtd/stm_nand.h    |  131 ++++
>  4 files changed, 1784 insertions(+)
>  create mode 100644 drivers/mtd/nand/stm_nand_bch.c
>  create mode 100644 include/linux/mtd/stm_nand.h
> 
> diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
> index f1cf503..2738eec 100644
> --- a/drivers/mtd/nand/Kconfig
> +++ b/drivers/mtd/nand/Kconfig
> @@ -513,4 +513,11 @@ config MTD_NAND_XWAY
>  	  Enables support for NAND Flash chips on Lantiq XWAY SoCs. NAND is attached
>  	  to the External Bus Unit (EBU).
>  
> +config MTD_NAND_STM_BCH
> +	tristate "STMicroelectronics: NANDi BCH Controller"
> +	depends on ARCH_STI
> +	depends on OF
> +	help
> +	  Adds support for the STMicroelectronics NANDi BCH Controller.
> +
>  endif # MTD_NAND
> diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
> index a035e7c..6044e0a 100644
> --- a/drivers/mtd/nand/Makefile
> +++ b/drivers/mtd/nand/Makefile
> @@ -41,6 +41,7 @@ obj-$(CONFIG_MTD_NAND_MLC_LPC32XX)      += lpc32xx_mlc.o
>  obj-$(CONFIG_MTD_NAND_SH_FLCTL)		+= sh_flctl.o
>  obj-$(CONFIG_MTD_NAND_MXC)		+= mxc_nand.o
>  obj-$(CONFIG_MTD_NAND_SOCRATES)		+= socrates_nand.o
> +obj-$(CONFIG_MTD_NAND_STM_BCH)		+= stm_nand_bch.o
>  obj-$(CONFIG_MTD_NAND_TXX9NDFMC)	+= txx9ndfmc.o
>  obj-$(CONFIG_MTD_NAND_NUC900)		+= nuc900_nand.o
>  obj-$(CONFIG_MTD_NAND_MPC5121_NFC)	+= mpc5121_nfc.o
> diff --git a/drivers/mtd/nand/stm_nand_bch.c b/drivers/mtd/nand/stm_nand_bch.c
> new file mode 100644
> index 0000000..9778792
> --- /dev/null
> +++ b/drivers/mtd/nand/stm_nand_bch.c
> @@ -0,0 +1,1645 @@
> +/*
> + * Support for STMicroelectronics NANDi BCH Controller
> + *
> + * Copyright (c) 2014 STMicroelectronics Limited
> + *
> + * Authors: Angus Clark <Angus.Clark@xxxxxx>
> + *	    Lee Jones <lee.jones@xxxxxxxxxx>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/delay.h>
> +#include <linux/io.h>
> +#include <linux/of.h>
> +#include <linux/clk.h>
> +#include <linux/interrupt.h>
> +#include <linux/device.h>
> +#include <linux/platform_device.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/completion.h>
> +#include <linux/of_mtd.h>
> +#include <linux/mtd/nand.h>
> +#include <linux/mtd/stm_nand_bbt.h>
> +#include <linux/mtd/stm_nand.h>
> +#include <linux/mtd/partitions.h>
> +
> +#include "stm_nand_regs.h"
> +
> +/* NANDi BCH Controller properties */
> +#define NANDI_BCH_SECTOR_SIZE			1024
> +#define NANDI_BCH_DMA_ALIGNMENT			64
> +#define NANDI_BCH_MAX_BUF_LIST			8
> +#define NANDI_BCH_BUF_LIST_SIZE			(4 * NANDI_BCH_MAX_BUF_LIST)
> +
> +#define PICO_TO_MILI(pico)			(pico / 1000)

You need parentheses around pico, since this macro is used in contexts
like:

	PICO_TO_MILI(a + b)

Also, the spelling is typically 'MILLI' not 'MILI', while you're at it.

> +
> +static int bch_ecc_strength[] = {
> +	[BCH_18BIT_ECC] = 18,
> +	[BCH_30BIT_ECC] = 30,
> +	[BCH_NO_ECC] = 0,
> +};
> +
> +/* BCH 'program' structure */
> +struct bch_prog {
> +	u32	multi_cs_addr[3];
> +	u32	multi_cs_config;
> +	u8	seq[16];
> +	u32	addr;
> +	u32	extra;
> +	u8	cmd[4];
> +	u32	reserved1;
> +	u32	gen_cfg;
> +	u32	delay;
> +	u32	reserved2;
> +	u32	seq_cfg;
> +};
> +
> +/* BCH template programs (modified on-the-fly) */
> +static struct bch_prog bch_prog_read_page = {
> +	.cmd = {
> +		NAND_CMD_READ0,
> +		NAND_CMD_READSTART,
> +	},
> +	.seq = {
> +		BCH_ECC_SCORE(0),
> +		BCH_CMD_ADDR,
> +		BCH_CL_CMD_1,
> +		BCH_DATA_2_SECTOR,
> +		BCH_STOP,
> +	},
> +	.gen_cfg = (GEN_CFG_DATA_8_NOT_16 |
> +		    GEN_CFG_EXTRA_ADD_CYCLE |
> +		    GEN_CFG_LAST_SEQ_NODE),
> +	.seq_cfg = SEQ_CFG_GO_STOP,
> +};
> +
> +static struct bch_prog bch_prog_write_page = {
> +	.cmd = {
> +		NAND_CMD_SEQIN,
> +		NAND_CMD_PAGEPROG,
> +		NAND_CMD_STATUS,
> +	},
> +	.seq = {
> +		BCH_CMD_ADDR,
> +		BCH_DATA_4_SECTOR,
> +		BCH_CL_CMD_1,
> +		BCH_CL_CMD_2,
> +		BCH_OP_ERR,
> +		BCH_STOP,
> +	},
> +	.gen_cfg = (GEN_CFG_DATA_8_NOT_16 |
> +		    GEN_CFG_EXTRA_ADD_CYCLE |
> +		    GEN_CFG_LAST_SEQ_NODE),
> +	.seq_cfg = (SEQ_CFG_GO_STOP |
> +		    SEQ_CFG_DATA_WRITE),
> +};
> +
> +static struct bch_prog bch_prog_erase_block = {
> +	.seq = {
> +		BCH_CL_CMD_1,
> +		BCH_AL_EX_0,
> +		BCH_AL_EX_1,
> +		BCH_AL_EX_2,
> +		BCH_CL_CMD_2,
> +		BCH_CL_CMD_3,
> +		BCH_OP_ERR,
> +		BCH_STOP,
> +	},
> +	.cmd = {
> +		NAND_CMD_ERASE1,
> +		NAND_CMD_ERASE1,
> +		NAND_CMD_ERASE2,
> +		NAND_CMD_STATUS,
> +	},
> +	.gen_cfg = (GEN_CFG_DATA_8_NOT_16 |
> +		    GEN_CFG_EXTRA_ADD_CYCLE |
> +		    GEN_CFG_LAST_SEQ_NODE),
> +	.seq_cfg = (SEQ_CFG_GO_STOP |
> +		    SEQ_CFG_ERASE),
> +};
> +
> +/* Configure BCH read/write/erase programs */
> +static void bch_configure_progs(struct nandi_controller *nandi)
> +{
> +	uint8_t data_opa = ffs(nandi->sectors_per_page) - 1;
> +	uint8_t data_instr = BCH_INSTR(BCH_OPC_DATA, data_opa);
> +	uint32_t gen_cfg_ecc = nandi->bch_ecc_mode << GEN_CFG_ECC_SHIFT;
> +
> +	/* Set 'DATA' instruction */
> +	bch_prog_read_page.seq[3] = data_instr;
> +	bch_prog_write_page.seq[1] = data_instr;
> +
> +	/* Set ECC mode */
> +	bch_prog_read_page.gen_cfg |= gen_cfg_ecc;
> +	bch_prog_write_page.gen_cfg |= gen_cfg_ecc;
> +	bch_prog_erase_block.gen_cfg |= gen_cfg_ecc;
> +
> +	/*
> +	 * Template sequences above are defined for devices that use 5 address
> +	 * cycles for page Read/Write operations (and 3 for Erase operations).
> +	 * Update sequences for devices that use 4 address cycles.
> +	 */
> +	if (!nandi->extra_addr) {
> +		/* Clear 'GEN_CFG_EXTRA_ADD_CYCLE' flag */
> +		bch_prog_read_page.gen_cfg &= ~GEN_CFG_EXTRA_ADD_CYCLE;
> +		bch_prog_write_page.gen_cfg &= ~GEN_CFG_EXTRA_ADD_CYCLE;
> +		bch_prog_erase_block.gen_cfg &= ~GEN_CFG_EXTRA_ADD_CYCLE;
> +
> +		/* Configure Erase sequence for 2 address cycles */
> +		/* (page address) */
> +		bch_prog_erase_block.seq[0] = BCH_CL_CMD_1;
> +		bch_prog_erase_block.seq[1] = BCH_AL_EX_0;
> +		bch_prog_erase_block.seq[2] = BCH_AL_EX_1;
> +		bch_prog_erase_block.seq[3] = BCH_CL_CMD_2;
> +		bch_prog_erase_block.seq[4] = BCH_CL_CMD_3;
> +		bch_prog_erase_block.seq[5] = BCH_OP_ERR;
> +		bch_prog_erase_block.seq[6] = BCH_STOP;
> +	}
> +}
> +
> +static inline bool bch_check_dma_alignment(const uint8_t *buf)
> +{
> +	if (((unsigned long)buf & (NANDI_BCH_DMA_ALIGNMENT - 1)) ||
> +	    !virt_addr_valid(buf)) /* vmalloc'd buffer! */
> +		return true;
> +
> +	return false;
> +}
> +
> +/*
> + * NANDi Interrupts (shared by Hamming and BCH controllers)
> + */
> +static irqreturn_t nandi_irq_handler(int irq, void *dev)
> +{
> +	struct nandi_controller *nandi = dev;
> +	unsigned int status;
> +
> +	status = readl(nandi->base + NANDBCH_INT_STA);
> +
> +	if (nandi->bch_ecc_mode && (status & NANDBCH_INT_SEQNODESOVER)) {
> +		/* BCH */
> +		writel(NANDBCH_INT_CLR_SEQNODESOVER,
> +		       nandi->base + NANDBCH_INT_CLR);
> +		complete(&nandi->seq_completed);
> +		return IRQ_HANDLED;
> +	}
> +	if (status & NAND_INT_RBN) {
> +		/* Hamming */
> +		writel(NAND_INT_CLR_RBN, nandi->base + NANDHAM_INT_CLR);
> +		complete(&nandi->rbn_completed);
> +		return IRQ_HANDLED;
> +	}
> +
> +	return IRQ_NONE;
> +}
> +
> +static void nandi_enable_interrupts(struct nandi_controller *nandi,
> +				    uint32_t irqs)
> +{
> +	uint32_t val;
> +
> +	val = readl(nandi->base + NANDBCH_INT_EN);
> +	val |= irqs;
> +	writel(val, nandi->base + NANDBCH_INT_EN);
> +}
> +
> +static void nandi_disable_interrupts(struct nandi_controller *nandi,
> +				     uint32_t irqs)
> +{
> +	uint32_t val;
> +
> +	val = readl(nandi->base + NANDBCH_INT_EN);
> +	val &= ~irqs;
> +	writel(val, nandi->base + NANDBCH_INT_EN);
> +}
> +
> +/*
> + * BCH Operations
> + */
> +static inline void bch_load_prog_cpu(struct nandi_controller *nandi,
> +				     struct bch_prog *prog)
> +{
> +	void __iomem *dst = nandi->base + NANDBCH_ADDRESS_REG_1;
> +	uint32_t *src = (uint32_t *)prog;
> +	int i;
> +
> +	for (i = 0; i < 16; i++) {
> +		/* Skip registers marked as "reserved" */
> +		if (i != 11 && i != 14)
> +			writel(*src, dst);
> +		src++;
> +		dst += sizeof(u32);
> +	}
> +}
> +
> +static void bch_wait_seq(struct nandi_controller *nandi)
> +{
> +	int err;
> +
> +	err = wait_for_completion_timeout(&nandi->seq_completed, HZ/2);
> +	if (!err)
> +		dev_err(nandi->dev, "BCH Seq timeout\n");
> +}
> +
> +static uint8_t bch_erase_block(struct nandi_controller *nandi,
> +			       loff_t offs)
> +{
> +	struct nand_chip *chip = &nandi->info.chip;
> +	struct bch_prog *prog = &bch_prog_erase_block;
> +	uint8_t status;
> +
> +	dev_dbg(nandi->dev, "%s: offs = 0x%012llx\n", __func__, offs);
> +
> +	prog->extra = (uint32_t)(offs >> chip->page_shift);
> +
> +	emiss_nandi_select(nandi, STM_NANDI_BCH);
> +
> +	nandi_enable_interrupts(nandi, NANDBCH_INT_SEQNODESOVER);
> +	reinit_completion(&nandi->seq_completed);
> +
> +	bch_load_prog_cpu(nandi, prog);
> +
> +	bch_wait_seq(nandi);
> +
> +	nandi_disable_interrupts(nandi, NANDBCH_INT_SEQNODESOVER);
> +
> +	status = (uint8_t)(readl(nandi->base +
> +				 NANDBCH_CHECK_STATUS_REG_A) & 0xff);
> +
> +	return status;
> +}
> +
> +static int bch_erase(struct mtd_info *mtd, int page)
> +{
> +	struct nand_chip *chip = mtd->priv;
> +	struct nandi_controller *nandi = chip->priv;
> +	uint32_t page_size = mtd->writesize;
> +	loff_t offs = (loff_t)page * page_size;
> +
> +	return bch_erase_block(nandi, offs);
> +}
> +
> +/*
> + * Detect an erased page, tolerating and correcting up to a specified number of
> + * bits at '0'.  (For many devices, it is now deemed within spec for an erased
> + * page to include a number of bits at '0', either as a result of read-disturb
> + * behaviour or 'stuck-at-zero' failures.)  Returns the number of corrected
> + * bits, or a '-1' if we have exceeded the maximum number of bits at '0' (likely
> + * to be a genuine uncorrectable ECC error).  In the latter case, the data must
> + * be returned unmodified, in accordance with the MTD API.
> + *
> + * The most robust approach would be to use Hamming-FLEX to re-read the entire
> + * raw page+OOB data.  However, it is assumed that just checking the returned
> + * 'raw' page data offers an acceptable compromise with minimal impact on
> + * performance.  (Is is possible to get a genuine uncorrectable ECC error where
> + * the page data is all 0xff?)

I'll answer the last question: yes. Reference: my last comments:

  http://lists.infradead.org/pipermail/linux-mtd/2014-October/055851.html

Please include a FIXME to clearly mark this paragraph as saying "this
approach is wrong, but I'm doing it anyway." I really shouldn't even
take this and have half a mind to just delete this function before
merging, since I've encouraged Boris in working on a correct solution
that can live in nand_base.c. (I see that you implemented OOB reads now,
so that should enable such an approach.)

> + */
> +static int check_erased_page(uint8_t *data, uint32_t page_size, int max_zeros)
> +{
> +	uint8_t *b = data;
> +	int zeros = 0;
> +	int i;
> +
> +	for (i = 0; i < page_size; i++) {
> +		zeros += hweight8(~*b++);
> +		if (zeros > max_zeros)
> +			return -1;
> +	}
> +
> +	if (zeros)
> +		memset(data, 0xff, page_size);
> +
> +	return zeros;
> +}
> +
> +/* Returns the number of ECC errors, or '-1' for uncorrectable error */
> +static int bch_read_page(struct nandi_controller *nandi,
> +			 loff_t offs,
> +			 uint8_t *buf)
> +{
> +	struct nand_chip *chip = &nandi->info.chip;
> +	struct bch_prog *prog = &bch_prog_read_page;
> +	uint32_t page_size = nandi->info.mtd.writesize;
> +	dma_addr_t list_phys;
> +	dma_addr_t buf_phys;
> +	uint32_t ecc_err;
> +	int err = 0;
> +
> +	dev_dbg(nandi->dev, "%s: offs = 0x%012llx\n", __func__, offs);
> +
> +	BUG_ON(offs & (NANDI_BCH_DMA_ALIGNMENT - 1));
> +
> +	emiss_nandi_select(nandi, STM_NANDI_BCH);
> +
> +	nandi_enable_interrupts(nandi, NANDBCH_INT_SEQNODESOVER);
> +	reinit_completion(&nandi->seq_completed);
> +
> +	/* Reset ECC stats */
> +	writel(CFG_RESET_ECC_ALL | CFG_ENABLE_AFM,
> +	       nandi->base + NANDBCH_CONTROLLER_CFG);
> +	writel(CFG_ENABLE_AFM, nandi->base + NANDBCH_CONTROLLER_CFG);
> +
> +	prog->addr = (uint32_t)((offs >> (chip->page_shift - 8)) & 0xffffff00);
> +
> +	buf_phys = dma_map_single(NULL, buf, page_size, DMA_FROM_DEVICE);
> +	if (dma_mapping_error(NULL, buf_phys))
> +		return -ENOMEM;
> +
> +	memset(nandi->buf_list, 0x00, NANDI_BCH_BUF_LIST_SIZE);
> +	nandi->buf_list[0] = buf_phys | (nandi->sectors_per_page - 1);
> +
> +	list_phys = dma_map_single(NULL, nandi->buf_list,
> +				   NANDI_BCH_BUF_LIST_SIZE, DMA_TO_DEVICE);
> +	if (dma_mapping_error(NULL, list_phys))
> +		return -ENOMEM;
> +
> +	writel(list_phys, nandi->base + NANDBCH_BUFFER_LIST_PTR);
> +
> +	bch_load_prog_cpu(nandi, prog);
> +
> +	bch_wait_seq(nandi);
> +
> +	nandi_disable_interrupts(nandi, NANDBCH_INT_SEQNODESOVER);
> +
> +	dma_unmap_single(NULL, list_phys, NANDI_BCH_BUF_LIST_SIZE,
> +			 DMA_TO_DEVICE);
> +	dma_unmap_single(NULL, buf_phys, page_size, DMA_FROM_DEVICE);
> +
> +	/* Use the maximum per-sector ECC count! */
> +	ecc_err = readl(nandi->base + NANDBCH_ECC_SCORE_REG_A) & 0xff;
> +	if (ecc_err == 0xff) {
> +		/*
> +		 * Downgrade uncorrectable ECC error for an erased page,
> +		 * tolerating 'bch_ecc_strength / 2' bits at zero.
> +		 */
> +		err = check_erased_page(buf, page_size, chip->ecc.strength / 2);
> +		if (err >= 0)
> +			dev_dbg(nandi->dev,
> +				"%s: erased page detected:\n"
> +				"  downgrading uncorrectable ECC error.\n",
> +				__func__);
> +	} else {
> +		err = (int)ecc_err;
> +	}
> +
> +	return err;
> +}
> +
> +static int bch_read(struct mtd_info *mtd, struct nand_chip *chip,
> +		    uint8_t *buf, int oob_required, int page)
> +{
> +	struct nandi_controller *nandi = chip->priv;
> +	uint32_t page_size = mtd->writesize;
> +	loff_t offs = (loff_t)page * page_size;
> +	bool bounce;
> +	uint8_t *p;
> +	int err;
> +
> +	bounce = bch_check_dma_alignment((const uint8_t *)buf);

What's the point of the 'const' cast?

> +	p = bounce ? nandi->page_buf : buf;
> +
> +	err = bch_read_page(nandi, offs, p);
> +	if (err < 0)
> +		mtd->ecc_stats.failed++;
> +	else
> +		mtd->ecc_stats.corrected += err;
> +
> +	if (bounce)
> +		memcpy(buf, p, page_size);
> +
> +	return err;
> +}
> +
> +/* Returns the status of the NAND device following the write operation */
> +static uint8_t bch_write_page(struct nandi_controller *nandi,
> +		       loff_t offs, const uint8_t *buf)
> +{
> +	struct nand_chip *chip = &nandi->info.chip;
> +	struct bch_prog *prog = &bch_prog_write_page;
> +	uint32_t page_size = nandi->info.mtd.writesize;
> +	uint8_t *p = (uint8_t *)buf;
> +	unsigned long list_phys;
> +	unsigned long buf_phys;
> +	uint8_t status;
> +	bool bounce;
> +
> +	dev_dbg(nandi->dev, "%s: offs = 0x%012llx\n", __func__, offs);
> +
> +	BUG_ON(offs & (page_size - 1));
> +
> +	bounce = bch_check_dma_alignment(buf);
> +	if (bounce) {
> +		memcpy(nandi->page_buf, buf, page_size);
> +		p = nandi->page_buf;
> +	}
> +
> +	emiss_nandi_select(nandi, STM_NANDI_BCH);
> +
> +	nandi_enable_interrupts(nandi, NANDBCH_INT_SEQNODESOVER);
> +	reinit_completion(&nandi->seq_completed);
> +
> +	prog->addr = (uint32_t)((offs >> (chip->page_shift - 8)) & 0xffffff00);
> +
> +	buf_phys = dma_map_single(NULL, p, page_size, DMA_TO_DEVICE);
> +	if (dma_mapping_error(NULL, buf_phys))
> +		return -ENOMEM;
> +
> +	memset(nandi->buf_list, 0x00, NANDI_BCH_BUF_LIST_SIZE);
> +	nandi->buf_list[0] = buf_phys | (nandi->sectors_per_page - 1);
> +
> +	list_phys = dma_map_single(NULL, nandi->buf_list,
> +				   NANDI_BCH_BUF_LIST_SIZE, DMA_TO_DEVICE);
> +	if (dma_mapping_error(NULL, list_phys))
> +		return -ENOMEM;
> +
> +	writel(list_phys, nandi->base + NANDBCH_BUFFER_LIST_PTR);
> +
> +	bch_load_prog_cpu(nandi, prog);
> +
> +	bch_wait_seq(nandi);
> +
> +	nandi_disable_interrupts(nandi, NANDBCH_INT_SEQNODESOVER);
> +
> +	dma_unmap_single(NULL, list_phys, NANDI_BCH_BUF_LIST_SIZE,
> +			 DMA_TO_DEVICE);
> +	dma_unmap_single(NULL, buf_phys, page_size, DMA_FROM_DEVICE);
> +
> +	status = (uint8_t)(readl(nandi->base +
> +				 NANDBCH_CHECK_STATUS_REG_A) & 0xff);
> +
> +	return status;
> +}
> +
> +static int bch_write(struct mtd_info *mtd, struct nand_chip *chip,
> +		     uint32_t offset, int data_len, const uint8_t *buf,
> +		     int oob_required, int page, int cached, int raw)
> +{
> +	struct nandi_controller *nandi = chip->priv;
> +	uint32_t page_size = mtd->writesize;
> +	loff_t offs = (loff_t)page * page_size;
> +	int err;
> +
> +	err = bch_write_page(nandi, offs, buf);
> +	if (err & NAND_STATUS_FAIL)
> +		return -EIO;
> +
> +	return 0;
> +}
> +
> +/*
> + * Hamming-FLEX operations
> + */
> +static int flex_wait_rbn(struct nandi_controller *nandi)
> +{
> +	int err;
> +
> +	err = wait_for_completion_timeout(&nandi->rbn_completed, HZ/2);
> +	if (!err)
> +		dev_err(nandi->dev, "FLEX RBn timeout\n");
> +
> +	return err;
> +}
> +
> +static void flex_cmd(struct nandi_controller *nandi, uint8_t cmd)
> +{
> +	uint32_t val;
> +
> +	val = (FLEX_CMD_CSN | FLEX_CMD_BEATS_1 | cmd);
> +	writel(val, nandi->base + NANDHAM_FLEX_CMD);
> +}
> +
> +static void flex_addr(struct nandi_controller *nandi,
> +		      uint32_t addr, int cycles)
> +{
> +	addr &= 0x00ffffff;
> +
> +	BUG_ON(cycles < 1);
> +	BUG_ON(cycles > 3);
> +
> +	addr |= (FLEX_ADDR_CSN | FLEX_ADDR_ADD8_VALID);
> +	addr |= (cycles & 0x3) << 28;
> +
> +	writel(addr, nandi->base + NANDHAM_FLEX_ADD);
> +}
> +
> +/*
> + * Partial implementation of MTD/NAND Interface, based on Hamming-FLEX
> + * operation.
> + *
> + * Allows us to make use of nand_base.c functions where possible
> + * (e.g. nand_scan_ident() and friends).
> + */
> +static void flex_command_lp(struct mtd_info *mtd, unsigned int command,
> +			    int column, int page)
> +{
> +	struct nand_chip *chip = mtd->priv;
> +	struct nandi_controller *nandi = chip->priv;
> +
> +	emiss_nandi_select(nandi, STM_NANDI_HAMMING);
> +
> +	switch (command) {
> +	case NAND_CMD_READOOB:
> +		/* Emulate NAND_CMD_READOOB */
> +		column += mtd->writesize;
> +		command = NAND_CMD_READ0;
> +		break;
> +	case NAND_CMD_READ0:
> +	case NAND_CMD_ERASE1:
> +	case NAND_CMD_SEQIN:
> +	case NAND_CMD_RESET:
> +	case NAND_CMD_PARAM:
> +		/* Prime RBn wait */
> +		nandi_enable_interrupts(nandi, NAND_INT_RBN);
> +		reinit_completion(&nandi->rbn_completed);
> +		break;
> +	case NAND_CMD_READID:
> +	case NAND_CMD_STATUS:
> +	case NAND_CMD_ERASE2:
> +		break;
> +	default:
> +		/* Catch unexpected commands */
> +		BUG();
> +	}
> +
> +	/*
> +	 * Command Cycle
> +	 */
> +	flex_cmd(nandi, command);
> +
> +	/*
> +	 * Address Cycles
> +	 */
> +	if (column != -1)
> +		flex_addr(nandi, column,
> +			  (command == NAND_CMD_READID) ? 1 : 2);
> +
> +	if (page != -1)
> +		flex_addr(nandi, page, nandi->extra_addr ? 3 : 2);
> +
> +	/* Complete 'READ0' command */
> +	if (command == NAND_CMD_READ0)
> +		flex_cmd(nandi, NAND_CMD_READSTART);
> +
> +	/* Wait for RBn, if required                        */
> +	/* (Note, other commands may handle wait elsewhere) */
> +	if (command == NAND_CMD_RESET ||
> +	    command == NAND_CMD_READ0 ||
> +	    command == NAND_CMD_PARAM) {
> +		flex_wait_rbn(nandi);
> +		nandi_disable_interrupts(nandi, NAND_INT_RBN);
> +	}
> +}
> +
> +static uint8_t flex_read_byte(struct mtd_info *mtd)
> +{
> +	struct nand_chip *chip = mtd->priv;
> +	struct nandi_controller *nandi = chip->priv;
> +
> +	emiss_nandi_select(nandi, STM_NANDI_HAMMING);
> +
> +	return (uint8_t)(readl(nandi->base + NANDHAM_FLEX_DATA) & 0xff);
> +}
> +
> +static int flex_wait_func(struct mtd_info *mtd, struct nand_chip *chip)
> +{
> +	struct nandi_controller *nandi = chip->priv;
> +
> +	emiss_nandi_select(nandi, STM_NANDI_HAMMING);
> +
> +	flex_wait_rbn(nandi);
> +
> +	flex_cmd(nandi, NAND_CMD_STATUS);
> +
> +	return (int)(readl(nandi->base + NANDHAM_FLEX_DATA) & 0xff);
> +}
> +
> +/* Multi-CS devices not supported */
> +static void flex_select_chip(struct mtd_info *mtd, int chipnr)
> +{
> +
> +}
> +
> +static void flex_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
> +{
> +	struct nand_chip *chip = mtd->priv;
> +	struct nandi_controller *nandi = chip->priv;
> +	int aligned;
> +
> +	emiss_nandi_select(nandi, STM_NANDI_HAMMING);
> +
> +	/* Read bytes until buf is 4-byte aligned */
> +	while (len && ((unsigned int)buf & 0x3)) {
> +		*buf++ = (uint8_t)(readl(nandi->base + NANDHAM_FLEX_DATA)
> +				   & 0xff);
> +		len--;
> +	};
> +
> +	/* Use 'BEATS_4'/readsl */
> +	if (len > 8) {
> +		aligned = len & ~0x3;
> +		writel(FLEX_DATA_CFG_BEATS_4 | FLEX_DATA_CFG_CSN,
> +		       nandi->base + NANDHAM_FLEX_DATAREAD_CONFIG);
> +
> +		readsl(nandi->base + NANDHAM_FLEX_DATA, buf, aligned >> 2);
> +
> +		buf += aligned;
> +		len -= aligned;
> +
> +		writel(FLEX_DATA_CFG_BEATS_1 | FLEX_DATA_CFG_CSN,
> +		       nandi->base + NANDHAM_FLEX_DATAREAD_CONFIG);
> +	}
> +
> +	/* Mop up remaining bytes */
> +	while (len > 0) {
> +		*buf++ = (uint8_t)(readl(nandi->base + NANDHAM_FLEX_DATA)
> +				   & 0xff);
> +		len--;
> +	}
> +}
> +
> +static void flex_write_buf(struct mtd_info *mtd, const uint8_t *buf, int len)
> +{
> +	struct nand_chip *chip = mtd->priv;
> +	struct nandi_controller *nandi = chip->priv;
> +	int aligned;
> +
> +	/* Write bytes until buf is 4-byte aligned */
> +	while (len && ((unsigned int)buf & 0x3)) {
> +		writel(*buf++, nandi->base + NANDHAM_FLEX_DATA);
> +		len--;
> +	};
> +
> +	/* USE 'BEATS_4/writesl */
> +	if (len > 8) {
> +		aligned = len & ~0x3;
> +		writel(FLEX_DATA_CFG_BEATS_4 | FLEX_DATA_CFG_CSN,
> +		       nandi->base + NANDHAM_FLEX_DATAWRITE_CONFIG);
> +		writesl(nandi->base + NANDHAM_FLEX_DATA, buf, aligned >> 2);
> +		buf += aligned;
> +		len -= aligned;
> +		writel(FLEX_DATA_CFG_BEATS_1 | FLEX_DATA_CFG_CSN,
> +		       nandi->base + NANDHAM_FLEX_DATAWRITE_CONFIG);
> +	}
> +
> +	/* Mop up remaining bytes */
> +	while (len > 0) {
> +		writel(*buf++, nandi->base + NANDHAM_FLEX_DATA);
> +		len--;
> +	}
> +}
> +
> +static int flex_read_raw(struct nandi_controller *nandi,
> +			 uint32_t page_addr,
> +			 uint32_t col_addr,
> +			 uint8_t *buf, uint32_t len)
> +{
> +	dev_dbg(nandi->dev, "%s %u bytes at [0x%06x,0x%04x]\n",
> +		__func__, len, page_addr, col_addr);
> +
> +	BUG_ON(len & 0x3);
> +	BUG_ON((unsigned long)buf & 0x3);
> +
> +	emiss_nandi_select(nandi, STM_NANDI_HAMMING);
> +	nandi_enable_interrupts(nandi, NAND_INT_RBN);
> +	reinit_completion(&nandi->rbn_completed);
> +
> +	writel(FLEX_DATA_CFG_BEATS_4 | FLEX_DATA_CFG_CSN,
> +	       nandi->base + NANDHAM_FLEX_DATAREAD_CONFIG);
> +
> +	flex_cmd(nandi, NAND_CMD_READ0);
> +	flex_addr(nandi, col_addr, 2);
> +	flex_addr(nandi, page_addr, nandi->extra_addr ? 3 : 2);
> +	flex_cmd(nandi, NAND_CMD_READSTART);
> +
> +	flex_wait_rbn(nandi);
> +
> +	readsl(nandi->base + NANDHAM_FLEX_DATA, buf, len / 4);
> +
> +	nandi_disable_interrupts(nandi, NAND_INT_RBN);
> +
> +	writel(FLEX_DATA_CFG_BEATS_1 | FLEX_DATA_CFG_CSN,
> +	       nandi->base + NANDHAM_FLEX_DATAREAD_CONFIG);
> +
> +	return 0;
> +}
> +
> +static int bch_mtd_read_oob(struct mtd_info *mtd,
> +			    struct nand_chip *chip, int page)
> +{
> +	struct nandi_controller *nandi = chip->priv;
> +
> +	return flex_read_raw(nandi, page, mtd->writesize,
> +			     chip->oob_poi, mtd->oobsize);
> +}
> +
> +static int bch_mtd_write_oob(struct mtd_info *mtd,
> +			     struct nand_chip *chip, int page)
> +{
> +	BUG();
> +	return 0;
> +}
> +
> +static int bch_read_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
> +			     uint8_t *buf, int oob_required, int page)
> +{
> +	BUG();
> +	return 0;
> +}
> +
> +static int bch_write_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
> +			      const uint8_t *buf, int oob_required)
> +{
> +	BUG();
> +	return 0;
> +}
> +
> +static void bch_hwctl(struct mtd_info *mtd, int mode)
> +{
> +	BUG();
> +}
> +
> +static int bch_calculate(struct mtd_info *mtd, const uint8_t *dat,
> +			 uint8_t *ecc_code)
> +{
> +	BUG();
> +	return 0;
> +}
> +
> +static int bch_correct(struct mtd_info *mtd, uint8_t *dat, uint8_t *read_ecc,
> +		       uint8_t *calc_ecc)
> +{
> +	BUG();
> +	return 0;
> +}
> +
> +/*
> + * Initialisation
> + */
> +static int bch_check_compatibility(struct nandi_controller *nandi,
> +				   struct mtd_info *mtd,
> +				   struct nand_chip *chip)
> +{
> +	if (chip->bits_per_cell > 1)
> +		dev_warn(nandi->dev, "MLC NAND not fully supported\n");
> +
> +	if (chip->options & NAND_BUSWIDTH_16) {
> +		dev_err(nandi->dev, "x16 NAND not supported\n");
> +		return false;
> +	}
> +
> +	if (nandi->blocks_per_device / 4 > mtd->writesize) {
> +		/* Need to implement multi-page BBT support... */
> +		dev_err(nandi->dev, "BBT too big to fit in single page\n");
> +		return false;
> +	}
> +
> +	if (bch_ecc_sizes[nandi->bch_ecc_mode] * nandi->sectors_per_page >
> +	    mtd->oobsize) {
> +		dev_err(nandi->dev, "insufficient OOB for selected ECC\n");
> +		return false;
> +	}
> +
> +	return true;
> +}
> +
> +/* Select strongest ECC scheme compatible with OOB size */
> +static int bch_set_ecc_auto(struct nandi_controller *nandi,
> +			    struct mtd_info *mtd)
> +{
> +	int oob_bytes_per_sector = mtd->oobsize / nandi->sectors_per_page;
> +	int try_ecc_modes[] = { BCH_30BIT_ECC, BCH_18BIT_ECC, -1 };
> +	int m, ecc_mode;
> +
> +	for (m = 0; try_ecc_modes[m] >= 0; m++) {
> +		ecc_mode = try_ecc_modes[m];
> +		if (oob_bytes_per_sector >= bch_ecc_sizes[ecc_mode]) {
> +			nandi->bch_ecc_mode = ecc_mode;
> +			return 0;
> +		}
> +	}
> +
> +	return -EINVAL;
> +}
> +
> +static void nandi_set_mtd_defaults(struct nandi_controller *nandi,
> +				   struct mtd_info *mtd, struct nand_chip *chip)
> +{
> +	struct nandi_info *info = &nandi->info;
> +	int i;
> +
> +	/* ecclayout */
> +	info->ecclayout.eccbytes = mtd->oobsize;
> +	for (i = 0; i < 64; i++)
> +		info->ecclayout.eccpos[i] = i;
> +	info->ecclayout.oobfree[0].offset = 0;
> +	info->ecclayout.oobfree[0].length = 0;
> +	chip->ecc.mode = NAND_ECC_HW;
> +
> +	/* nand_chip */
> +	chip->controller = &chip->hwcontrol;
> +	spin_lock_init(&chip->controller->lock);
> +	init_waitqueue_head(&chip->controller->wq);
> +	chip->state = FL_READY;
> +	chip->priv = nandi;
> +	chip->ecc.layout = &info->ecclayout;
> +	chip->options |= NAND_NO_SUBPAGE_WRITE;
> +
> +	chip->cmdfunc = flex_command_lp;
> +	chip->read_byte = flex_read_byte;
> +	chip->select_chip = flex_select_chip;
> +	chip->waitfunc = flex_wait_func;
> +	chip->read_buf = flex_read_buf;
> +	chip->write_buf = flex_write_buf;
> +
> +	chip->bbt_options |= NAND_BBT_USE_FLASH;
> +
> +	/* mtd_info */
> +	mtd->owner = THIS_MODULE;
> +	mtd->type = MTD_NANDFLASH;
> +	mtd->flags = MTD_CAP_NANDFLASH;
> +	mtd->ecclayout = &info->ecclayout;
> +
> +	chip->ecc.hwctl = bch_hwctl;
> +	chip->ecc.calculate = bch_calculate;
> +	chip->ecc.correct = bch_correct;
> +
> +	chip->ecc.read_oob = bch_mtd_read_oob;
> +	chip->ecc.write_oob = bch_mtd_write_oob;
> +
> +	chip->ecc.read_page = bch_read;
> +	chip->ecc.read_page_raw = bch_read_page_raw;
> +	chip->ecc.write_page_raw = bch_write_page_raw;
> +	chip->write_page = bch_write;
> +	chip->erase = bch_erase;
> +
> +#ifdef CONFIG_MTD_NAND_STM_BCH_BBT
> +	chip->scan_bbt = bch_scan_bbt;
> +	chip->block_bad = bch_block_isbad;
> +	chip->block_markbad = bch_block_markbad;
> +#endif
> +}
> +
> +/*
> + * Timing and Clocks
> + */
> +
> +static void nandi_clk_enable(struct nandi_controller *nandi)
> +{
> +	clk_prepare_enable(nandi->emi_clk);
> +	clk_prepare_enable(nandi->bch_clk);
> +}
> +
> +static void nandi_clk_disable(struct nandi_controller *nandi)
> +{
> +	clk_disable_unprepare(nandi->emi_clk);
> +	clk_disable_unprepare(nandi->bch_clk);
> +}
> +
> +static struct clk *nandi_clk_setup(struct nandi_controller *nandi,
> +				   char *clkname)
> +{
> +	struct clk *clk;
> +	int err;
> +
> +	clk = devm_clk_get(nandi->dev, clkname);
> +	if (IS_ERR_OR_NULL(clk)) {
> +		dev_warn(nandi->dev, "Failed to get %s clock\n", clkname);
> +		return NULL;
> +	}
> +
> +	err = clk_prepare_enable(clk);
> +	if (err) {
> +		dev_warn(nandi->dev, "Failed to enable %s clock\n", clkname);
> +		return NULL;
> +	}
> +
> +	return clk;
> +}
> +
> +/* Derive Hamming-FLEX timing register values from 'nand_sdr_timings' data */
> +static void flex_calc_timing_registers(const struct nand_sdr_timings *spec,
> +				       int tCLK, int relax,
> +				       uint32_t *ctl_timing,
> +				       uint32_t *wen_timing,
> +				       uint32_t *ren_timing)
> +{
> +	int tMAX_HOLD;
> +	int n_ctl_setup;
> +	int n_ctl_hold;
> +	int n_ctl_wb;
> +
> +	int tMAX_WEN_OFF;
> +	int n_wen_on;
> +	int n_wen_off;
> +
> +	int tMAX_REN_OFF;
> +	int n_ren_on;
> +	int n_ren_off;
> +
> +	/*
> +	 * CTL_TIMING
> +	 */
> +
> +	/*	- SETUP */
> +	n_ctl_setup = (PICO_TO_MILI(spec->tCLS_min - spec->tWP_min)
> +		       + tCLK - 1) / tCLK;
> +	if (n_ctl_setup < 1)
> +		n_ctl_setup = 1;
> +	n_ctl_setup += relax;
> +
> +	/*	- HOLD */
> +	tMAX_HOLD = spec->tCLH_min;
> +	if (spec->tCH_min > tMAX_HOLD)
> +		tMAX_HOLD = spec->tCH_min;
> +	if (spec->tALH_min > tMAX_HOLD)
> +		tMAX_HOLD = spec->tALH_min;
> +	if (spec->tDH_min > tMAX_HOLD)
> +		tMAX_HOLD = spec->tDH_min;
> +	n_ctl_hold = (PICO_TO_MILI(tMAX_HOLD) + tCLK - 1) / tCLK + relax;
> +
> +	/*	- CE_deassert_hold = 0 */
> +
> +	/*	- WE_high_to_RBn_low */
> +	n_ctl_wb = (PICO_TO_MILI(spec->tWB_max) + tCLK - 1) / tCLK;
> +
> +	*ctl_timing = ((n_ctl_setup & 0xff) |
> +		       (n_ctl_hold & 0xff) << 8 |
> +		       (n_ctl_wb & 0xff) << 24);
> +
> +	/*
> +	 * WEN_TIMING
> +	 */
> +
> +	/*	- ON */
> +	n_wen_on = (PICO_TO_MILI(spec->tWH_min) + tCLK - 1) / tCLK + relax;
> +
> +	/*	- OFF */
> +	tMAX_WEN_OFF = spec->tWC_min - spec->tWH_min;
> +	if (spec->tWP_min > tMAX_WEN_OFF)
> +		tMAX_WEN_OFF = spec->tWP_min;
> +	n_wen_off = (PICO_TO_MILI(tMAX_WEN_OFF) + tCLK - 1) / tCLK + relax;
> +
> +	*wen_timing = ((n_wen_on & 0xff) |
> +		       (n_wen_off & 0xff) << 8);
> +
> +	/*
> +	 * REN_TIMING
> +	 */
> +
> +	/*	- ON */
> +	n_ren_on = (PICO_TO_MILI(spec->tREH_min) + tCLK - 1) / tCLK + relax;
> +
> +	/*	- OFF */
> +	tMAX_REN_OFF = spec->tRC_min - spec->tREH_min;
> +	if (spec->tRP_min > tMAX_REN_OFF)
> +		tMAX_REN_OFF = spec->tRP_min;
> +	if (spec->tREA_max > tMAX_REN_OFF)
> +		tMAX_REN_OFF = spec->tREA_max;
> +	n_ren_off = (PICO_TO_MILI(tMAX_REN_OFF) + tCLK - 1) / tCLK + 1 + relax;
> +
> +	*ren_timing = ((n_ren_on & 0xff) |
> +		       (n_ren_off & 0xff) << 8);
> +}
> +
> +/* Derive BCH timing register values from 'nand_sdr_timings' data */
> +static void bch_calc_timing_registers(const struct nand_sdr_timings *spec,
> +				      int tCLK, int relax,
> +				      uint32_t *ctl_timing,
> +				      uint32_t *wen_timing,
> +				      uint32_t *ren_timing)
> +{
> +	int tMAX_HOLD;
> +	int n_ctl_setup;
> +	int n_ctl_hold;
> +	int n_ctl_wb;
> +
> +	int n_wen_on;
> +	int n_wen_off;
> +	int wen_half_on;
> +	int wen_half_off;
> +
> +	int tMAX_REN_ON;
> +	int tMAX_CS_DEASSERT;
> +	int n_d_latch;
> +	int n_telqv;
> +	int n_ren_on;
> +	int n_ren_off;
> +
> +	/*
> +	 * CTL_TIMING
> +	 */
> +
> +	/*	- SETUP */
> +	if (spec->tCLS_min > spec->tWP_min)
> +		n_ctl_setup = (PICO_TO_MILI(spec->tCLS_min - spec->tWP_min)
> +			       + tCLK - 1) / tCLK;
> +	else
> +		n_ctl_setup = 0;
> +	n_ctl_setup += relax;
> +
> +	/*	- HOLD */
> +	tMAX_HOLD = spec->tCLH_min;
> +	if (spec->tCH_min > tMAX_HOLD)
> +		tMAX_HOLD = spec->tCH_min;
> +	if (spec->tALH_min > tMAX_HOLD)
> +		tMAX_HOLD = spec->tALH_min;
> +	if (spec->tDH_min > tMAX_HOLD)
> +		tMAX_HOLD = spec->tDH_min;
> +	n_ctl_hold = (PICO_TO_MILI(tMAX_HOLD) + tCLK - 1) / tCLK + relax;
> +	/*	- CE_deassert_hold = 0 */
> +
> +	/*	- WE_high_to_RBn_low */
> +	n_ctl_wb = (PICO_TO_MILI(spec->tWB_max) + tCLK - 1) / tCLK;
> +
> +	*ctl_timing = ((n_ctl_setup & 0xff) |
> +		       (n_ctl_hold & 0xff) << 8 |
> +		       (n_ctl_wb & 0xff) << 24);
> +
> +	/*
> +	 * WEN_TIMING
> +	 */
> +
> +	/*	- ON */
> +	n_wen_on = (2 * PICO_TO_MILI(spec->tWH_min) + tCLK - 1) / tCLK;
> +	wen_half_on = n_wen_on % 2;
> +	n_wen_on /= 2;
> +	n_wen_on += relax;
> +
> +	/*	- OFF */
> +	n_wen_off = (2 * PICO_TO_MILI(spec->tWP_min) + tCLK - 1) / tCLK;
> +	wen_half_off = n_wen_off % 2;
> +	n_wen_off /= 2;
> +	n_wen_off += relax;
> +
> +	*wen_timing = ((n_wen_on & 0xff) |
> +		       (n_wen_off & 0xff) << 8 |
> +		       (wen_half_on << 16) |
> +		       (wen_half_off << 17));
> +
> +	/*
> +	 * REN_TIMING
> +	 */
> +
> +	/*	- ON */
> +	tMAX_REN_ON = spec->tRC_min - spec->tRP_min;
> +	if (spec->tREH_min > tMAX_REN_ON)
> +		tMAX_REN_ON = spec->tREH_min;
> +
> +	n_ren_on = (2 * PICO_TO_MILI(tMAX_REN_ON) + tCLK - 1) / tCLK;
> +	n_ren_on /= 2;
> +	n_ren_on += relax;
> +
> +	/*	- OFF */
> +	n_ren_off = (2 * PICO_TO_MILI(spec->tREA_max) + tCLK - 1) / tCLK;
> +	n_ren_off /= 2;
> +	n_ren_off += relax;
> +
> +	/*	- DATA_LATCH */
> +	if (PICO_TO_MILI(spec->tREA_max) <=
> +	    (PICO_TO_MILI(spec->tRP_min) - (2 * tCLK)))
> +		n_d_latch = 0;
> +	else if (PICO_TO_MILI(spec->tREA_max) <=
> +		 (PICO_TO_MILI(spec->tRP_min) - tCLK))
> +		n_d_latch = 1;
> +	else if ((spec->tREA_max <= spec->tRP_min) &&
> +		 (PICO_TO_MILI(spec->tRHOH_min) >= 2 * tCLK))
> +		n_d_latch = 2;
> +	else
> +		n_d_latch = 3;
> +
> +	/*	- TELQV */
> +	tMAX_CS_DEASSERT = spec->tCOH_min;
> +	if (spec->tCHZ_max > tMAX_CS_DEASSERT)
> +		tMAX_CS_DEASSERT = spec->tCHZ_max;
> +
> +	n_telqv = (PICO_TO_MILI(tMAX_CS_DEASSERT) + tCLK - 1) / tCLK;
> +
> +	*ren_timing = ((n_ren_on & 0xff) |
> +		       (n_ren_off & 0xff) << 8 |
> +		       (n_d_latch & 0x3) << 16 |
> +		       (wen_half_on << 18) |
> +		       (wen_half_off << 19) |
> +		       (n_telqv & 0xff) << 24);
> +}
> +
> +static void flex_configure_timing_registers(struct nandi_controller *nandi,
> +					    const struct nand_sdr_timings *spec,
> +					    int relax)
> +{
> +	uint32_t ctl_timing;
> +	uint32_t wen_timing;
> +	uint32_t ren_timing;
> +	int emi_t_ns;
> +
> +	/* Select Hamming Controller */
> +	emiss_nandi_select(nandi, STM_NANDI_HAMMING);
> +
> +	/* Get EMI clock (default 100MHz) */
> +	if (nandi->emi_clk)
> +		emi_t_ns = 1000000000UL / clk_get_rate(nandi->emi_clk);
> +	else {
> +		dev_warn(nandi->dev,
> +			 "No EMI clock available; assuming default 100MHz\n");
> +		emi_t_ns = 10;
> +	}
> +
> +	/* Derive timing register values from specification */
> +	flex_calc_timing_registers(spec, emi_t_ns, relax,
> +				   &ctl_timing, &wen_timing, &ren_timing);
> +
> +	dev_dbg(nandi->dev,
> +		"updating FLEX timing configuration [0x%08x, 0x%08x, 0x%08x]\n",
> +		ctl_timing, wen_timing, ren_timing);
> +
> +	/* Program timing registers */
> +	writel(ctl_timing, nandi->base + NANDHAM_CTL_TIMING);
> +	writel(wen_timing, nandi->base + NANDHAM_WEN_TIMING);
> +	writel(ren_timing, nandi->base + NANDHAM_REN_TIMING);
> +}
> +
> +static void bch_configure_timing_registers(struct nandi_controller *nandi,
> +					   const struct nand_sdr_timings *spec,
> +					   int relax)
> +{
> +	uint32_t ctl_timing;
> +	uint32_t wen_timing;
> +	uint32_t ren_timing;
> +	int bch_t_ns;
> +
> +	/* Select BCH Controller */
> +	emiss_nandi_select(nandi, STM_NANDI_BCH);
> +
> +	/* Get BCH clock (default 200MHz) */
> +	if (nandi->bch_clk)
> +		bch_t_ns = 1000000000UL / clk_get_rate(nandi->bch_clk);
> +	else {
> +		dev_warn(nandi->dev,
> +			 "No BCH clock available; assuming default 200MHz\n");
> +		bch_t_ns = 5;
> +	}
> +
> +	/* Derive timing register values from specification */
> +	bch_calc_timing_registers(spec, bch_t_ns, relax,
> +				  &ctl_timing, &wen_timing, &ren_timing);
> +
> +	dev_dbg(nandi->dev,
> +		"updating BCH timing configuration [0x%08x, 0x%08x, 0x%08x]\n",
> +		ctl_timing, wen_timing, ren_timing);
> +
> +	/* Program timing registers */
> +	writel(ctl_timing, nandi->base + NANDBCH_CTL_TIMING);
> +	writel(wen_timing, nandi->base + NANDBCH_WEN_TIMING);
> +	writel(ren_timing, nandi->base + NANDBCH_REN_TIMING);
> +}
> +
> +static void nandi_configure_timing_registers(struct nandi_controller *nandi,
> +					const struct nand_sdr_timings *spec,
> +					int relax)
> +{
> +	bch_configure_timing_registers(nandi, spec, relax);
> +	flex_configure_timing_registers(nandi, spec, relax);
> +}
> +
> +static void nandi_init_hamming(struct nandi_controller *nandi, int emi_bank)
> +{
> +	dev_dbg(nandi->dev, "%s\n", __func__);
> +
> +	emiss_nandi_select(nandi, STM_NANDI_HAMMING);
> +
> +	/* Reset and disable boot-mode controller */
> +	writel(BOOT_CFG_RESET, nandi->base + NANDHAM_BOOTBANK_CFG);
> +	udelay(1);
> +	writel(0x00000000, nandi->base + NANDHAM_BOOTBANK_CFG);
> +
> +	/* Reset controller */
> +	writel(CFG_RESET, nandi->base + NANDHAM_FLEXMODE_CFG);
> +	udelay(1);
> +	writel(0x00000000, nandi->base + NANDHAM_FLEXMODE_CFG);
> +
> +	/* Set EMI Bank */
> +	writel(0x1 << emi_bank, nandi->base + NANDHAM_FLEX_MUXCTRL);
> +
> +	/* Enable FLEX mode */
> +	writel(CFG_ENABLE_FLEX, nandi->base + NANDHAM_FLEXMODE_CFG);
> +
> +	/* Configure FLEX_DATA_READ/WRITE for 1-byte access */
> +	writel(FLEX_DATA_CFG_BEATS_1 | FLEX_DATA_CFG_CSN,
> +	       nandi->base + NANDHAM_FLEX_DATAREAD_CONFIG);
> +	writel(FLEX_DATA_CFG_BEATS_1 | FLEX_DATA_CFG_CSN,
> +	       nandi->base + NANDHAM_FLEX_DATAREAD_CONFIG);
> +
> +	/* RBn interrupt on rising edge */
> +	writel(NAND_EDGE_CFG_RBN_RISING, nandi->base + NANDHAM_INT_EDGE_CFG);
> +
> +	/* Enable interrupts */
> +	nandi_enable_interrupts(nandi, NAND_INT_ENABLE);
> +}
> +
> +static void nandi_init_bch(struct nandi_controller *nandi, int emi_bank)
> +{
> +	dev_dbg(nandi->dev, "%s\n", __func__);
> +
> +	/* Initialise BCH Controller */
> +	emiss_nandi_select(nandi, STM_NANDI_BCH);
> +
> +	/* Reset and disable boot-mode controller */
> +	writel(BOOT_CFG_RESET, nandi->base + NANDBCH_BOOTBANK_CFG);
> +	udelay(1);
> +	writel(0x00000000, nandi->base + NANDBCH_BOOTBANK_CFG);
> +
> +	/* Reset AFM controller */
> +	writel(CFG_RESET, nandi->base + NANDBCH_CONTROLLER_CFG);
> +	udelay(1);
> +	writel(0x00000000, nandi->base + NANDBCH_CONTROLLER_CFG);
> +
> +	/* Set EMI Bank */
> +	writel(0x1 << emi_bank, nandi->base + NANDBCH_FLEX_MUXCTRL);
> +
> +	/* Reset ECC stats */
> +	writel(CFG_RESET_ECC_ALL, nandi->base + NANDBCH_CONTROLLER_CFG);
> +	udelay(1);
> +
> +	/* Enable AFM */
> +	writel(CFG_ENABLE_AFM, nandi->base + NANDBCH_CONTROLLER_CFG);
> +
> +	/* Configure Read DMA Plugs (values supplied by Validation) */
> +	writel(0x00000005, nandi->dma + EMISS_NAND_RD_DMA_PAGE_SIZE);
> +	writel(0x00000005, nandi->dma + EMISS_NAND_RD_DMA_MAX_OPCODE_SIZE);
> +	writel(0x00000002, nandi->dma + EMISS_NAND_RD_DMA_MIN_OPCODE_SIZE);
> +	writel(0x00000001, nandi->dma + EMISS_NAND_RD_DMA_MAX_CHUNK_SIZE);
> +	writel(0x00000000, nandi->dma + EMISS_NAND_RD_DMA_MAX_MESSAGE_SIZE);
> +
> +	/* Configure Write DMA Plugs (values supplied by Validation) */
> +	writel(0x00000005, nandi->dma + EMISS_NAND_WR_DMA_PAGE_SIZE);
> +	writel(0x00000005, nandi->dma + EMISS_NAND_WR_DMA_MAX_OPCODE_SIZE);
> +	writel(0x00000002, nandi->dma + EMISS_NAND_WR_DMA_MIN_OPCODE_SIZE);
> +	writel(0x00000001, nandi->dma + EMISS_NAND_WR_DMA_MAX_CHUNK_SIZE);
> +	writel(0x00000000, nandi->dma + EMISS_NAND_WR_DMA_MAX_MESSAGE_SIZE);
> +
> +	nandi_enable_interrupts(nandi, NAND_INT_ENABLE);
> +}
> +
> +static void nandi_init_controller(struct nandi_controller *nandi,
> +				  int emi_bank)
> +{
> +	nandi_init_bch(nandi, emi_bank);
> +	nandi_init_hamming(nandi, emi_bank);
> +}
> +
> +/* Initialise working buffers, accomodating DMA alignment constraints */
> +static int nandi_init_working_buffers(struct nandi_controller *nandi,
> +				      struct nandi_bbt_info *bbt_info,
> +				      struct mtd_info *mtd)
> +{
> +	uint32_t bbt_buf_size;
> +	uint32_t buf_size;
> +
> +	/*	- Page and OOB */
> +	buf_size = mtd->writesize + mtd->oobsize + NANDI_BCH_DMA_ALIGNMENT;
> +
> +	/*	- BBT data (page-size aligned) */
> +	bbt_info->bbt_size = nandi->blocks_per_device >> 2; /* 2 bits/block */
> +	bbt_buf_size = ALIGN(bbt_info->bbt_size, mtd->writesize);
> +	buf_size += bbt_buf_size + NANDI_BCH_DMA_ALIGNMENT;
> +
> +	/*	- BCH BUF list */
> +	buf_size += NANDI_BCH_BUF_LIST_SIZE + NANDI_BCH_DMA_ALIGNMENT;
> +
> +	/* Allocate bufffer */
> +	nandi->buf = devm_kzalloc(nandi->dev, buf_size, GFP_KERNEL);
> +	if (!nandi->buf)
> +		return -ENOMEM;
> +
> +	/* Set/Align buffer pointers */
> +	nandi->page_buf = PTR_ALIGN(nandi->buf, NANDI_BCH_DMA_ALIGNMENT);
> +	nandi->oob_buf  = nandi->page_buf + mtd->writesize;
> +	bbt_info->bbt   = PTR_ALIGN(nandi->oob_buf + mtd->oobsize,
> +				    NANDI_BCH_DMA_ALIGNMENT);
> +	nandi->buf_list = (uint32_t *)PTR_ALIGN(bbt_info->bbt + bbt_buf_size,
> +						NANDI_BCH_DMA_ALIGNMENT);
> +
> +	return 0;
> +}
> +
> +static struct nandi_controller *
> +nandi_init_resources(struct platform_device *pdev)
> +{
> +	struct stm_nand_bch_ddata *ddata = platform_get_drvdata(pdev);
> +	struct nandi_controller *nandi;
> +	struct resource *res;
> +	int irq;
> +	int err;
> +
> +	nandi = devm_kzalloc(&pdev->dev, sizeof(*nandi), GFP_KERNEL);
> +	if (!nandi)
> +		return ERR_PTR(-ENOMEM);
> +
> +	nandi->dev = &pdev->dev;
> +
> +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "emi_nand");
> +	nandi->base = devm_ioremap_resource(&pdev->dev, res);
> +	if (IS_ERR(nandi->base))
> +		return nandi->base;
> +
> +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "emiss");
> +	nandi->emiss = devm_ioremap_resource(&pdev->dev, res);
> +	if (IS_ERR(nandi->emiss))
> +		return nandi->emiss;
> +
> +	nandi->dma = nandi->emiss + EMISS_NAND_DMA;
> +	nandi->emisscfg = nandi->emiss + EMISS_CFG;
> +
> +	irq = platform_get_irq_byname(pdev, "nand_irq");
> +	if (irq < 0) {
> +		dev_err(&pdev->dev, "failed to find IRQ resource\n");
> +		return ERR_PTR(irq);
> +	}
> +
> +	err = devm_request_irq(&pdev->dev, irq, nandi_irq_handler,
> +			       IRQF_DISABLED, dev_name(&pdev->dev), nandi);
> +	if (err) {
> +		dev_err(&pdev->dev, "irq request failed\n");
> +		return ERR_PTR(err);
> +	}
> +
> +	nandi->emi_clk = nandi_clk_setup(nandi, "emi");
> +	nandi->bch_clk = nandi_clk_setup(nandi, "bch");
> +
> +	ddata->nandi = nandi;
> +
> +	return nandi;
> +}
> +
> +/**
> + * stm_of_get_nand_banks - Get nand banks info from a given device node.
> + *
> + * @dev			device pointer to use for devm allocations.
> + * @np			device node of the driver.
> + * @banksptr		double pointer to banks which is allocated
> + *			and filled with bank data.
> + *
> + * Returns a count of banks found in the given device node.
> + *
> + */
> +int stm_of_get_nand_banks(struct device *dev, struct device_node *np,
> +			  struct stm_nand_bank_data **banksptr)
> +{
> +	struct stm_nand_bank_data *banks;
> +	struct device_node *banknp;
> +	int nr_banks = 0;
> +
> +	if (!np)
> +		return -ENODEV;
> +
> +	nr_banks = of_get_child_count(np);
> +	if (!nr_banks) {
> +		dev_err(dev, "No NAND banks specified in DT: %s\n",
> +		np->full_name);
> +		return -EINVAL;
> +	}
> +
> +	*banksptr = devm_kzalloc(dev, sizeof(*banks) * nr_banks, GFP_KERNEL);
> +	if (!*banksptr)
> +		return -ENOMEM;
> +
> +	banks = *banksptr;
> +
> +	for_each_available_child_of_node(np, banknp) {
> +		int bank = 0;
> +
> +		of_property_read_u32(banknp, "nand-chip-select",
> +				     &banks[bank].csn);
> +
> +		if (of_get_nand_bus_width(banknp) == 16)
> +			banks[bank].options |= NAND_BUSWIDTH_16;
> +		if (of_get_nand_on_flash_bbt(banknp))
> +			banks[bank].bbt_options |= NAND_BBT_USE_FLASH;

Hmm, these fields (options and bbt_optinos) are never used anywhere. You
need to rewrite this.

> +
> +		banks[bank].nr_partitions = 0;
> +		banks[bank].partitions = NULL;

You never assign these to non-zero. So why do you have the fields?

> +
> +		of_property_read_u32(banknp, "st,nand-timing-relax",
> +				     &banks[bank].timing_relax);
> +		bank++;
> +	}
> +
> +	return nr_banks;
> +}
> +
> +static void *stm_bch_dt_get_ddata(struct platform_device *pdev)
> +{
> +	struct device_node *np = pdev->dev.of_node;
> +	struct stm_nand_bch_ddata *ddata;
> +	int ecc_strength;
> +	int err;
> +
> +	ddata = devm_kzalloc(&pdev->dev, sizeof(*ddata), GFP_KERNEL);
> +	if (!ddata)
> +		return ERR_PTR(-ENOMEM);
> +
> +	ecc_strength = of_get_nand_ecc_strength(np);
> +	if (ecc_strength == 0)
> +		ddata->bch_ecc_cfg = BCH_NO_ECC;
> +	else if (ecc_strength == 18)
> +		ddata->bch_ecc_cfg = BCH_18BIT_ECC;
> +	else if (ecc_strength == 30)
> +		ddata->bch_ecc_cfg = BCH_30BIT_ECC;
> +	else
> +		ddata->bch_ecc_cfg = BCH_ECC_AUTO;
> +
> +	err = stm_of_get_nand_banks(&pdev->dev, np, &ddata->bank);
> +	if (err < 0)
> +		return ERR_PTR(err);
> +
> +	return ddata;
> +}
> +
> +static int stm_nand_bch_probe(struct platform_device *pdev)
> +{
> +	struct device_node *np = pdev->dev.of_node;
> +	struct mtd_part_parser_data ppdata;
> +	struct stm_nand_bch_ddata *ddata;
> +	struct stm_nand_bank_data *bank;
> +	struct nandi_bbt_info *bbt_info;
> +	struct nandi_controller *nandi;
> +	struct nandi_info *info;
> +	struct nand_chip *chip;
> +	struct mtd_info *mtd;
> +	int compatible, err;
> +
> +	if (!np) {
> +		dev_err(&pdev->dev, "DT node not found\n");
> +		return -EINVAL;
> +	}
> +
> +	ddata = stm_bch_dt_get_ddata(pdev);
> +	if (IS_ERR(ddata))
> +		return PTR_ERR(ddata);
> +
> +	platform_set_drvdata(pdev, ddata);
> +
> +	nandi = nandi_init_resources(pdev);
> +	if (IS_ERR(nandi)) {
> +		dev_err(&pdev->dev, "failed to initialise NANDi resources\n");
> +		return PTR_ERR(nandi);
> +	}
> +
> +	init_completion(&nandi->seq_completed);
> +	init_completion(&nandi->rbn_completed);
> +
> +	bank = ddata->bank;
> +	if (bank)
> +		nandi_init_controller(nandi, bank->csn);
> +
> +	info            = &nandi->info;
> +	chip            = &info->chip;
> +	bbt_info        = &info->bbt_info;
> +	mtd             = &info->mtd;
> +	mtd->priv       = chip;
> +	mtd->name       = dev_name(&pdev->dev);
> +	mtd->dev.parent = &pdev->dev;
> +
> +	nandi_set_mtd_defaults(nandi, mtd, chip);
> +
> +	err = nand_scan_ident(mtd, 1, NULL);
> +	if (err)
> +		return err;
> +
> +	/*
> +	 * Configure timing registers
> +	 */
> +	if (chip->onfi_version) {
> +		int mode = fls(onfi_get_async_timing_mode(chip) - 1);
> +		const struct nand_sdr_timings *spec =
> +			onfi_async_timing_mode_to_sdr_timings(mode);
> +
> +		/* Modes 4 and 5 (EDO) are not supported on our H/W */
> +		if (mode > 3)
> +			mode = 3;
> +
> +		dev_info(&pdev->dev, "Using ONFI Timing Mode %d\n", mode);
> +		nandi_configure_timing_registers(nandi,	spec,
> +					bank ? bank->timing_relax : 0);
> +	} else {
> +		dev_warn(&pdev->dev, "No timing data available\n");
> +	}
> +
> +	if (mtd->writesize < NANDI_BCH_SECTOR_SIZE) {
> +		dev_err(nandi->dev,
> +			"page size incompatible with BCH ECC sector\n");
> +		return -EINVAL;
> +	}
> +
> +	/* Derive some working variables */
> +	nandi->sectors_per_page = mtd->writesize / NANDI_BCH_SECTOR_SIZE;
> +	nandi->blocks_per_device = mtd->size >> chip->phys_erase_shift;
> +	nandi->extra_addr = ((chip->chipsize >> chip->page_shift) >
> +			     0x10000) ? true : false;

The ternary '?' isn't necessary. Thet first argument is already a
boolean expression.

> +
> +	/* Set ECC mode */
> +	if (ddata->bch_ecc_cfg == BCH_ECC_AUTO) {
> +		err = bch_set_ecc_auto(nandi, mtd);
> +		if (err) {
> +			dev_err(nandi->dev, "insufficient OOB for BCH ECC\n");
> +			return err;
> +		}
> +	} else {
> +		nandi->bch_ecc_mode = ddata->bch_ecc_cfg;
> +	}
> +
> +	chip->ecc.size = NANDI_BCH_SECTOR_SIZE;
> +	chip->ecc.bytes = mtd->oobsize / (mtd->writesize / chip->ecc.size);
> +	chip->ecc.strength = bch_ecc_strength[nandi->bch_ecc_mode];
> +
> +	info->ecclayout.eccbytes =
> +		nandi->sectors_per_page * bch_ecc_sizes[nandi->bch_ecc_mode];
> +
> +	compatible = bch_check_compatibility(nandi, mtd, chip);
> +	if (!compatible) {
> +		dev_err(nandi->dev,
> +			"NAND device incompatible with NANDi/BCH Controller\n");
> +		return -EINVAL;
> +	}
> +
> +	/* Tune BCH programs according to device found and ECC mode */
> +	bch_configure_progs(nandi);
> +
> +	err = nandi_init_working_buffers(nandi, bbt_info, mtd);
> +	if (err)
> +		return err;
> +
> +	err = nand_scan_tail(mtd);
> +	if (err)
> +		return err;
> +
> +#ifdef CONFIG_MTD_NAND_STM_BCH_BBT
> +	nandi_dump_bad_blocks(nandi);
> +#endif
> +	/* Add partitions */
> +	ppdata.of_node = of_get_next_available_child(np, NULL);

OK, so you're registering only a single MTD with partitions determined
by the first bank's subnodes. You've essentially ignored all other
banks. I think you need to take a good hard look at your whole bank DT
structure as well as your use of stm_bch_dt_get_ddata() and
stm_of_get_nand_banks(). I think you should answer these questions,
mostly for your own sake:

1. Do you intend to support multiple banks (chip selects)?

2. How many MTDs should be created for each bank?

3. What properties belong to each bank? e.g., I see that you have ECC
   strength defined gloablly (not per-bank), and I see that some
   properties which are defined in your DT are not actually handled
   appropriately (I commented above)

I think after answering these questions, the conclusion is probably that
you need to really comb through this driver to straighten this out.

For reference, I think the pxa3xx_nand driver has a better handle on
these questions, and it requires a for loop over all chip-selects to
register each one.

> +	return mtd_device_parse_register(mtd, NULL, &ppdata,
> +					 bank ? bank->partitions : NULL,
> +					 bank ? bank->nr_partitions : 0);
> +}
> +
> +static int stm_nand_bch_remove(struct platform_device *pdev)
> +{
> +	struct stm_nand_bch_ddata *ddata = platform_get_drvdata(pdev);
> +	struct nandi_controller *nandi = ddata->nandi;
> +
> +	nand_release(&nandi->info.mtd);
> +
> +	nandi_clk_disable(nandi);
> +
> +	return 0;
> +}
> +
> +static int stm_nand_bch_suspend(struct device *dev)
> +{
> +	struct stm_nand_bch_ddata *ddata = dev_get_drvdata(dev);
> +	struct nandi_controller *nandi = ddata->nandi;
> +
> +	nandi_clk_disable(nandi);
> +
> +	return 0;
> +}
> +static int stm_nand_bch_resume(struct device *dev)
> +{
> +	struct stm_nand_bch_ddata *ddata = dev_get_drvdata(dev);
> +	struct nandi_controller *nandi = ddata->nandi;
> +
> +	nandi_clk_enable(nandi);
> +
> +	return 0;
> +}

You need to wrap the above two functions in #ifdef CONFIG_PM_SLEEP,
otherwise you get 'unused' warnings with !CONFIG_PM_SLEEP.

> +
> +static SIMPLE_DEV_PM_OPS(stm_nand_bch_pm_ops,
> +			 stm_nand_bch_suspend,
> +			 stm_nand_bch_resume);
> +
> +static struct of_device_id nand_bch_match[] = {
> +	{ .compatible = "st,nand-bch", },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, nand_bch_match);
> +
> +static struct platform_driver stm_nand_bch_driver = {
> +	.probe	= stm_nand_bch_probe ,
> +	.remove	= stm_nand_bch_remove,
> +	.driver	= {
> +		.name	= "stm-nand-bch",
> +		.owner	= THIS_MODULE,

This assignment isn't necessary. module_platform_driver takes care of
it.

> +		.of_match_table = of_match_ptr(nand_bch_match),
> +		.pm	= &stm_nand_bch_pm_ops,
> +	},
> +};
> +module_platform_driver(stm_nand_bch_driver);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_AUTHOR("Angus Clark");
> +MODULE_DESCRIPTION("STM NAND BCH driver");
> diff --git a/include/linux/mtd/stm_nand.h b/include/linux/mtd/stm_nand.h
> new file mode 100644
> index 0000000..231f598
> --- /dev/null
> +++ b/include/linux/mtd/stm_nand.h
> @@ -0,0 +1,131 @@
> +/*
> + * include/linux/mtd/stm_mtd.h
> + *
> + * Support for STMicroelectronics NAND Controllers
> + *
> + * Copyright (c) 2014 STMicroelectronics Limited
> + * Author: Angus Clark <Angus.Clark@xxxxxx>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + */
> +
> +#ifndef __LINUX_STM_NAND_H
> +#define __LINUX_STM_NAND_H
> +
> +#include <linux/io.h>
> +#include <linux/mtd/nand.h>
> +
> +/* ECC Modes */
> +enum stm_nand_bch_ecc_config {
> +	BCH_18BIT_ECC = 0,
> +	BCH_30BIT_ECC,
> +	BCH_NO_ECC,
> +	BCH_ECC_RSRV,
> +	BCH_ECC_AUTO,
> +};
> +
> +/* Bad Block Table (BBT) */
> +struct nandi_bbt_info {
> +	uint32_t	bbt_size;		/* Size of bad-block table */
> +	uint32_t	bbt_vers[2];		/* Version (Primary/Mirror) */
> +	uint32_t	bbt_block[2];		/* Block No. (Primary/Mirror) */
> +	uint8_t		*bbt;			/* Table data */
> +};
> +
> +/* Collection of MTD/NAND device information */
> +struct nandi_info {
> +	struct mtd_info		mtd;		/* MTD info */
> +	struct nand_chip	chip;		/* NAND chip info */
> +
> +	struct nand_ecclayout	ecclayout;	/* MTD ECC layout */
> +	struct nandi_bbt_info	bbt_info;	/* Bad Block Table */
> +	int			nr_parts;	/* Number of MTD partitions */
> +	struct	mtd_partition	*parts;		/* MTD partitions */
> +};
> +
> +/* NANDi Controller (Hamming/BCH) */
> +struct nandi_controller {
> +	void __iomem		*base;		/* Controller base*/
> +	void __iomem		*emiss;		/* EMISS control base */
> +	void __iomem		*emisscfg;	/* EMISS config base */
> +	void __iomem		*dma;		/* DMA control base */
> +
> +	struct clk		*bch_clk;
> +	struct clk		*emi_clk;
> +						/* IRQ-triggered Completions: */
> +	struct completion	seq_completed;	/*   SEQ Over */
> +	struct completion	rbn_completed;	/*   RBn */
> +
> +	struct device		*dev;
> +
> +	int			bch_ecc_mode;	/* ECC mode */
> +	bool			extra_addr;	/* Extra address cycle */
> +
> +	uint32_t		blocks_per_device;
> +	uint32_t		sectors_per_page;
> +
> +	uint8_t			*buf;		/* Some buffers to use */
> +	uint8_t			*page_buf;
> +	uint8_t			*oob_buf;
> +	uint32_t		*buf_list;
> +
> +	struct nandi_info	info;		/* NAND device info */
> +};
> +
> +/*
> + * Board-level specification relating to a 'bank' of NAND Flash
> + */
> +struct stm_nand_bank_data {
> +	int			csn;
> +	int			nr_partitions;
> +	struct mtd_partition	*partitions;
> +	unsigned int		options;
> +	unsigned int		bbt_options;
> +
> +	/*
> +	 * No. of IP clk cycles by which to 'relax' the timing configuration.
> +	 * Required on some boards to to accommodate board-level limitations.
> +	 * Used in conjunction with 'nand_sdr_timings' and ONFI configuration.
> +	 */
> +	int			timing_relax;
> +};
> +
> +struct stm_nand_bch_ddata {
> +	struct nandi_controller *nandi;
> +	struct stm_nand_bank_data *bank;
> +	enum stm_nand_bch_ecc_config bch_ecc_cfg;
> +};
> +
> +enum nandi_controllers {
> +	STM_NANDI_UNCONFIGURED,
> +	STM_NANDI_HAMMING,
> +	STM_NANDI_BCH
> +};
> +
> +#define EMISS_NAND_CONFIG_HAMMING_NOT_BCH	(0x1 << 6)
> +
> +static inline void emiss_nandi_select(struct nandi_controller *nandi,
> +				      enum nandi_controllers controller)
> +{
> +	unsigned v;
> +
> +	v = readl(nandi->emisscfg);
> +
> +	if (controller == STM_NANDI_HAMMING) {
> +		if (v & EMISS_NAND_CONFIG_HAMMING_NOT_BCH)
> +			return;
> +		v |= EMISS_NAND_CONFIG_HAMMING_NOT_BCH;
> +	} else {
> +		if (!(v & EMISS_NAND_CONFIG_HAMMING_NOT_BCH))
> +			return;
> +		v &= ~EMISS_NAND_CONFIG_HAMMING_NOT_BCH;
> +	}
> +
> +	writel(v, nandi->emisscfg);
> +	readl(nandi->emisscfg);
> +}
> +
> +#endif /* __LINUX_STM_NAND_H */

Brian
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