[v2,4/4] mtd: rawnand: brcmnand: exec_op implementation

exec_op implementation for Broadcom STB, Broadband and iProc SoC
This adds exec_op and removes the legacy interface. Based on changes
proposed by Boris Brezillon.

https://github.com/bbrezillon/linux/commit/4ec6f8d8d83f5aaca5d1877f02d48da96d41fcba
https://github.com/bbrezillon/linux/commit/11b4acffd761c4928652d7028d19fcd6f45e4696

Signed-off-by: David Regan <dregan@mail.com>

---

Changes in v2: moved status and reset command detect out of loop
---
 drivers/mtd/nand/raw/brcmnand/brcmnand.c | 374 +++++++++--------------
 1 file changed, 151 insertions(+), 223 deletions(-)

--
2.37.3

Hello,

dregan@mail.com wrote on Thu, 12 Oct 2023 02:42:37 +0200:

> exec_op implementation for Broadcom STB, Broadband and iProc SoC
> This adds exec_op and removes the legacy interface. Based on changes
> proposed by Boris Brezillon.
> 
> https://github.com/bbrezillon/linux/commit/4ec6f8d8d83f5aaca5d1877f02d48da96d41fcba
> https://github.com/bbrezillon/linux/commit/11b4acffd761c4928652d7028d19fcd6f45e4696
> 
> Signed-off-by: David Regan <dregan@mail.com>
> 
> ---
> 
> Changes in v2: moved status and reset command detect out of loop
> ---
>  drivers/mtd/nand/raw/brcmnand/brcmnand.c | 374 +++++++++--------------
>  1 file changed, 151 insertions(+), 223 deletions(-)
> 
> diff --git a/drivers/mtd/nand/raw/brcmnand/brcmnand.c b/drivers/mtd/nand/raw/brcmnand/brcmnand.c
> index 8d429eb3b72a..f1b0ca3ebc9c 100644
> --- a/drivers/mtd/nand/raw/brcmnand/brcmnand.c
> +++ b/drivers/mtd/nand/raw/brcmnand/brcmnand.c
> @@ -625,6 +625,8 @@ enum {
>  /* Only for v7.2 */
>  #define	ACC_CONTROL_ECC_EXT_SHIFT		13
> 
> +static u8 brcmnand_status(struct brcmnand_host *host);
> +
>  static inline bool brcmnand_non_mmio_ops(struct brcmnand_controller *ctrl)
>  {
>  #if IS_ENABLED(CONFIG_MTD_NAND_BRCMNAND_BCMA)
> @@ -1022,19 +1024,6 @@ static inline int brcmnand_sector_1k_shift(struct brcmnand_controller *ctrl)
>  		return -1;
>  }
> 
> -static int brcmnand_get_sector_size_1k(struct brcmnand_host *host)
> -{
> -	struct brcmnand_controller *ctrl = host->ctrl;
> -	int shift = brcmnand_sector_1k_shift(ctrl);
> -	u16 acc_control_offs = brcmnand_cs_offset(ctrl, host->cs,
> -						  BRCMNAND_CS_ACC_CONTROL);
> -
> -	if (shift < 0)
> -		return 0;
> -
> -	return (nand_readreg(ctrl, acc_control_offs) >> shift) & 0x1;
> -}
> -
>  static void brcmnand_set_sector_size_1k(struct brcmnand_host *host, int val)
>  {
>  	struct brcmnand_controller *ctrl = host->ctrl;
> @@ -1074,6 +1063,9 @@ static int bcmnand_ctrl_poll_status(struct brcmnand_host *host,
> 
>  	limit = jiffies + msecs_to_jiffies(timeout_ms);
>  	do {
> +		if (mask & INTFC_FLASH_STATUS)
> +			brcmnand_status(host);
> +
>  		val = brcmnand_read_reg(ctrl, BRCMNAND_INTFC_STATUS);
>  		if ((val & mask) == expected_val)
>  			return 0;
> @@ -1388,7 +1380,8 @@ static void brcmnand_wp(struct mtd_info *mtd, int wp)
>  			return;
> 
>  		brcmnand_set_wp(ctrl, wp);
> -		nand_status_op(chip, NULL);
> +		/* force controller operation to update internal copy of NAND chip status */
> +		brcmnand_status(host);
>  		/* NAND_STATUS_WP 0x00 = protected, 0x80 = not protected */
>  		ret = bcmnand_ctrl_poll_status(host,
>  					       NAND_CTRL_RDY |
> @@ -1644,16 +1637,6 @@ static void brcmnand_send_cmd(struct brcmnand_host *host, int cmd)
>  			   cmd << brcmnand_cmd_shift(ctrl));
>  }
> 
> -/***********************************************************************
> - * NAND MTD API: read/program/erase
> - ***********************************************************************/
> -
> -static void brcmnand_cmd_ctrl(struct nand_chip *chip, int dat,
> -			      unsigned int ctrl)
> -{
> -	/* intentionally left blank */
> -}
> -
>  static bool brcmstb_nand_wait_for_completion(struct nand_chip *chip)
>  {
>  	struct brcmnand_host *host = nand_get_controller_data(chip);
> @@ -1704,6 +1687,17 @@ static int brcmnand_waitfunc(struct nand_chip *chip)
>  				 INTFC_FLASH_STATUS;
>  }
> 
> +static u8 brcmnand_status(struct brcmnand_host *host)
> +{
> +	struct nand_chip *chip = &host->chip;
> +	struct mtd_info *mtd = nand_to_mtd(chip);
> +
> +	brcmnand_set_cmd_addr(mtd, 0);
> +	brcmnand_send_cmd(host, CMD_STATUS_READ);
> +
> +	return brcmnand_waitfunc(chip);
> +}
> +
>  enum {
>  	LLOP_RE				= BIT(16),
>  	LLOP_WE				= BIT(17),
> @@ -1753,190 +1747,6 @@ static int brcmnand_low_level_op(struct brcmnand_host *host,
>  	return brcmnand_waitfunc(chip);
>  }
> 
> -static void brcmnand_cmdfunc(struct nand_chip *chip, unsigned command,
> -			     int column, int page_addr)
> -{
> -	struct mtd_info *mtd = nand_to_mtd(chip);
> -	struct brcmnand_host *host = nand_get_controller_data(chip);
> -	struct brcmnand_controller *ctrl = host->ctrl;
> -	u64 addr = (u64)page_addr << chip->page_shift;
> -	int native_cmd = 0;
> -
> -	if (command == NAND_CMD_READID || command == NAND_CMD_PARAM ||
> -			command == NAND_CMD_RNDOUT)
> -		addr = (u64)column;
> -	/* Avoid propagating a negative, don't-care address */
> -	else if (page_addr < 0)
> -		addr = 0;
> -
> -	dev_dbg(ctrl->dev, "cmd 0x%x addr 0x%llx\n", command,
> -		(unsigned long long)addr);
> -
> -	host->last_cmd = command;
> -	host->last_byte = 0;
> -	host->last_addr = addr;
> -
> -	switch (command) {
> -	case NAND_CMD_RESET:
> -		native_cmd = CMD_FLASH_RESET;
> -		break;
> -	case NAND_CMD_STATUS:
> -		native_cmd = CMD_STATUS_READ;
> -		break;
> -	case NAND_CMD_READID:
> -		native_cmd = CMD_DEVICE_ID_READ;
> -		break;
> -	case NAND_CMD_READOOB:
> -		native_cmd = CMD_SPARE_AREA_READ;
> -		break;
> -	case NAND_CMD_ERASE1:
> -		native_cmd = CMD_BLOCK_ERASE;
> -		brcmnand_wp(mtd, 0);
> -		break;
> -	case NAND_CMD_PARAM:
> -		native_cmd = CMD_PARAMETER_READ;
> -		break;
> -	case NAND_CMD_SET_FEATURES:
> -	case NAND_CMD_GET_FEATURES:
> -		brcmnand_low_level_op(host, LL_OP_CMD, command, false);
> -		brcmnand_low_level_op(host, LL_OP_ADDR, column, false);
> -		break;
> -	case NAND_CMD_RNDOUT:
> -		native_cmd = CMD_PARAMETER_CHANGE_COL;
> -		addr &= ~((u64)(FC_BYTES - 1));
> -		/*
> -		 * HW quirk: PARAMETER_CHANGE_COL requires SECTOR_SIZE_1K=0
> -		 * NB: hwcfg.sector_size_1k may not be initialized yet
> -		 */
> -		if (brcmnand_get_sector_size_1k(host)) {
> -			host->hwcfg.sector_size_1k =
> -				brcmnand_get_sector_size_1k(host);
> -			brcmnand_set_sector_size_1k(host, 0);
> -		}
> -		break;
> -	}
> -
> -	if (!native_cmd)
> -		return;
> -
> -	brcmnand_set_cmd_addr(mtd, addr);
> -	brcmnand_send_cmd(host, native_cmd);
> -	brcmnand_waitfunc(chip);
> -
> -	if (native_cmd == CMD_PARAMETER_READ ||
> -			native_cmd == CMD_PARAMETER_CHANGE_COL) {
> -		/* Copy flash cache word-wise */
> -		u32 *flash_cache = (u32 *)ctrl->flash_cache;
> -		int i;
> -
> -		brcmnand_soc_data_bus_prepare(ctrl->soc, true);
> -
> -		/*
> -		 * Must cache the FLASH_CACHE now, since changes in
> -		 * SECTOR_SIZE_1K may invalidate it
> -		 */
> -		for (i = 0; i < FC_WORDS; i++)
> -			/*
> -			 * Flash cache is big endian for parameter pages, at
> -			 * least on STB SoCs
> -			 */
> -			flash_cache[i] = be32_to_cpu(brcmnand_read_fc(ctrl, i));
> -
> -		brcmnand_soc_data_bus_unprepare(ctrl->soc, true);
> -
> -		/* Cleanup from HW quirk: restore SECTOR_SIZE_1K */
> -		if (host->hwcfg.sector_size_1k)
> -			brcmnand_set_sector_size_1k(host,
> -						    host->hwcfg.sector_size_1k);
> -	}
> -
> -	/* Re-enable protection is necessary only after erase */
> -	if (command == NAND_CMD_ERASE1)
> -		brcmnand_wp(mtd, 1);
> -}
> -
> -static uint8_t brcmnand_read_byte(struct nand_chip *chip)
> -{
> -	struct brcmnand_host *host = nand_get_controller_data(chip);
> -	struct brcmnand_controller *ctrl = host->ctrl;
> -	uint8_t ret = 0;
> -	int addr, offs;
> -
> -	switch (host->last_cmd) {
> -	case NAND_CMD_READID:
> -		if (host->last_byte < 4)
> -			ret = brcmnand_read_reg(ctrl, BRCMNAND_ID) >>
> -				(24 - (host->last_byte << 3));
> -		else if (host->last_byte < 8)
> -			ret = brcmnand_read_reg(ctrl, BRCMNAND_ID_EXT) >>
> -				(56 - (host->last_byte << 3));
> -		break;
> -
> -	case NAND_CMD_READOOB:
> -		ret = oob_reg_read(ctrl, host->last_byte);
> -		break;
> -
> -	case NAND_CMD_STATUS:
> -		ret = brcmnand_read_reg(ctrl, BRCMNAND_INTFC_STATUS) &
> -					INTFC_FLASH_STATUS;
> -		if (wp_on) /* hide WP status */
> -			ret |= NAND_STATUS_WP;
> -		break;
> -
> -	case NAND_CMD_PARAM:
> -	case NAND_CMD_RNDOUT:
> -		addr = host->last_addr + host->last_byte;
> -		offs = addr & (FC_BYTES - 1);
> -
> -		/* At FC_BYTES boundary, switch to next column */
> -		if (host->last_byte > 0 && offs == 0)
> -			nand_change_read_column_op(chip, addr, NULL, 0, false);
> -
> -		ret = ctrl->flash_cache[offs];
> -		break;
> -	case NAND_CMD_GET_FEATURES:
> -		if (host->last_byte >= ONFI_SUBFEATURE_PARAM_LEN) {
> -			ret = 0;
> -		} else {
> -			bool last = host->last_byte ==
> -				ONFI_SUBFEATURE_PARAM_LEN - 1;
> -			brcmnand_low_level_op(host, LL_OP_RD, 0, last);
> -			ret = brcmnand_read_reg(ctrl, BRCMNAND_LL_RDATA) & 0xff;
> -		}
> -	}
> -
> -	dev_dbg(ctrl->dev, "read byte = 0x%02x\n", ret);
> -	host->last_byte++;
> -
> -	return ret;
> -}
> -
> -static void brcmnand_read_buf(struct nand_chip *chip, uint8_t *buf, int len)
> -{
> -	int i;
> -
> -	for (i = 0; i < len; i++, buf++)
> -		*buf = brcmnand_read_byte(chip);
> -}
> -
> -static void brcmnand_write_buf(struct nand_chip *chip, const uint8_t *buf,
> -			       int len)
> -{
> -	int i;
> -	struct brcmnand_host *host = nand_get_controller_data(chip);
> -
> -	switch (host->last_cmd) {
> -	case NAND_CMD_SET_FEATURES:
> -		for (i = 0; i < len; i++)
> -			brcmnand_low_level_op(host, LL_OP_WR, buf[i],
> -						  (i + 1) == len);
> -		break;
> -	default:
> -		BUG();
> -		break;
> -	}
> -}
> -
>  /*
>   *  Kick EDU engine
>   */
> @@ -2346,8 +2156,9 @@ static int brcmnand_read_page(struct nand_chip *chip, uint8_t *buf,
>  	struct mtd_info *mtd = nand_to_mtd(chip);
>  	struct brcmnand_host *host = nand_get_controller_data(chip);
>  	u8 *oob = oob_required ? (u8 *)chip->oob_poi : NULL;
> +	u64 addr = (u64)page << chip->page_shift;
> 
> -	nand_read_page_op(chip, page, 0, NULL, 0);
> +	host->last_addr = addr;
> 
>  	return brcmnand_read(mtd, chip, host->last_addr,
>  			mtd->writesize >> FC_SHIFT, (u32 *)buf, oob);
> @@ -2360,8 +2171,9 @@ static int brcmnand_read_page_raw(struct nand_chip *chip, uint8_t *buf,
>  	struct mtd_info *mtd = nand_to_mtd(chip);
>  	u8 *oob = oob_required ? (u8 *)chip->oob_poi : NULL;
>  	int ret;
> +	u64 addr = (u64)page << chip->page_shift;
> 
> -	nand_read_page_op(chip, page, 0, NULL, 0);
> +	host->last_addr = addr;
> 
>  	brcmnand_set_ecc_enabled(host, 0);
>  	ret = brcmnand_read(mtd, chip, host->last_addr,
> @@ -2469,11 +2281,11 @@ static int brcmnand_write_page(struct nand_chip *chip, const uint8_t *buf,
>  	struct mtd_info *mtd = nand_to_mtd(chip);
>  	struct brcmnand_host *host = nand_get_controller_data(chip);
>  	void *oob = oob_required ? chip->oob_poi : NULL;
> +	u64 addr = (u64)page << chip->page_shift;
> 
> -	nand_prog_page_begin_op(chip, page, 0, NULL, 0);
> -	brcmnand_write(mtd, chip, host->last_addr, (const u32 *)buf, oob);
> +	host->last_addr = addr;
> 
> -	return nand_prog_page_end_op(chip);
> +	return brcmnand_write(mtd, chip, host->last_addr, (const u32 *)buf, oob);
>  }
> 
>  static int brcmnand_write_page_raw(struct nand_chip *chip, const uint8_t *buf,
> @@ -2482,13 +2294,15 @@ static int brcmnand_write_page_raw(struct nand_chip *chip, const uint8_t *buf,
>  	struct mtd_info *mtd = nand_to_mtd(chip);
>  	struct brcmnand_host *host = nand_get_controller_data(chip);
>  	void *oob = oob_required ? chip->oob_poi : NULL;
> +	u64 addr = (u64)page << chip->page_shift;
> +	int ret = 0;
> 
> -	nand_prog_page_begin_op(chip, page, 0, NULL, 0);
> +	host->last_addr = addr;
>  	brcmnand_set_ecc_enabled(host, 0);
> -	brcmnand_write(mtd, chip, host->last_addr, (const u32 *)buf, oob);
> +	ret = brcmnand_write(mtd, chip, host->last_addr, (const u32 *)buf, oob);
>  	brcmnand_set_ecc_enabled(host, 1);
> 
> -	return nand_prog_page_end_op(chip);
> +	return ret;
>  }
> 
>  static int brcmnand_write_oob(struct nand_chip *chip, int page)
> @@ -2512,6 +2326,125 @@ static int brcmnand_write_oob_raw(struct nand_chip *chip, int page)
>  	return ret;
>  }
> 
> +static int brcmnand_exec_instr(struct brcmnand_host *host,
> +				const struct nand_op_instr *instr,
> +				bool last_op)
> +{
> +	struct brcmnand_controller *ctrl = host->ctrl;
> +	unsigned int i;
> +	const u8 *out;
> +	u8 *in;
> +	int ret = 0;
> +
> +	bcmnand_ctrl_poll_status(host, NAND_CTRL_RDY, NAND_CTRL_RDY, 0);
> +
> +	switch (instr->type) {
> +	case NAND_OP_CMD_INSTR:
> +		brcmnand_low_level_op(host, LL_OP_CMD,
> +				      instr->ctx.cmd.opcode, last_op);
> +		break;
> +
> +	case NAND_OP_ADDR_INSTR:
> +		for (i = 0; i < instr->ctx.addr.naddrs; i++)
> +			brcmnand_low_level_op(host, LL_OP_ADDR,
> +					      instr->ctx.addr.addrs[i],
> +					      last_op);
> +		break;
> +
> +	case NAND_OP_DATA_IN_INSTR:
> +		in = instr->ctx.data.buf.in;
> +		for (i = 0; i < instr->ctx.data.len; i++) {
> +			brcmnand_low_level_op(host, LL_OP_RD, 0, last_op);
> +			in[i] = brcmnand_read_reg(host->ctrl,
> +						  BRCMNAND_LL_RDATA);
> +		}
> +		break;
> +
> +	case NAND_OP_DATA_OUT_INSTR:
> +		out = instr->ctx.data.buf.out;
> +		for (i = 0; i < instr->ctx.data.len; i++)
> +			brcmnand_low_level_op(host, LL_OP_WR, out[i], last_op);
> +		break;
> +
> +	default:
> +		dev_err(ctrl->dev, "unsupported instruction type: %d\n",
> +			instr->type);
> +		ret = -EINVAL;
> +		break;
> +	}
> +
> +	return ret;
> +}
> +
> +int brcmnand_exec_op_is_status(const struct nand_operation *op)
> +{
> +	if ((op->instrs[0].type == NAND_OP_CMD_INSTR) &&
> +		(op->instrs[0].ctx.cmd.opcode == NAND_CMD_STATUS) &&
> +		(op->ninstrs > 1) &&
> +		(op->instrs[1].type == NAND_OP_DATA_IN_INSTR))

You need to start checking if op->ninstrs == 2, no?

> +		return 1;
> +
> +	return 0;
> +}
> +
> +int brcmnand_exec_op_is_reset(const struct nand_operation *op)
> +{
> +	if ((op->instrs[0].type == NAND_OP_CMD_INSTR) &&
> +		(op->instrs[0].ctx.cmd.opcode == NAND_CMD_RESET))

Please check ninstrs as well (first).

> +		return 1;
> +
> +	return 0;
> +}
> +
> +static int brcmnand_exec_op(struct nand_chip *chip,
> +			    const struct nand_operation *op,
> +			    bool check_only)
> +{
> +	struct brcmnand_host *host = nand_get_controller_data(chip);
> +	struct mtd_info *mtd = nand_to_mtd(chip);
> +	const struct nand_op_instr *instr = &op->instrs[0];
> +	u8 *status;
> +	unsigned int i;
> +	int ret = 0;
> +
> +	if (check_only)
> +		return 0;
> +
> +	if (brcmnand_exec_op_is_status(op)) {
> +		status = op->instrs[1].ctx.data.buf.in;
> +		*status = brcmnand_status(host);
> +
> +		return 0;
> +	}
> +
> +	if (op->deassert_wp)
> +		brcmnand_wp(mtd, 0);
> +
> +	for (i = 0; i < op->ninstrs; i++) {
> +		instr = &op->instrs[i];
> +
> +		if (instr->type == NAND_OP_WAITRDY_INSTR) {
> +			ret = bcmnand_ctrl_poll_status(host, NAND_CTRL_RDY, NAND_CTRL_RDY, 0);

Why don't you handle this in brcmnand_exec_instr() ? It would look much
nicer. Even if this does not involve any additional "cycle" on the NAND
bus, it still is an instruction of the current operation.

> +			if (ret)
> +				break;
> +		} else { /* otherwise pass to low level implementation */
> +			ret = brcmnand_exec_instr(host, instr, i == (op->ninstrs - 1));

What's the point of this i == op->ninstrs - 1 check?

> +			if (ret)
> +				break;
> +		}
> +	}
> +
> +	if (op->deassert_wp)
> +		brcmnand_wp(mtd, 1);
> +
> +	if (brcmnand_exec_op_is_reset(op)) {
> +		brcmnand_status(host);
> +		brcmnand_wp(mtd, 1);

This should be done right after the status check, no?

Anyway, I'm not sure I understand this. Why do you read the status and
assert WP?

> +	}
> +
> +	return ret;
> +}
> +
>  /***********************************************************************
>   * Per-CS setup (1 NAND device)
>   ***********************************************************************/
> @@ -2822,6 +2755,7 @@ static int brcmnand_attach_chip(struct nand_chip *chip)
> 
>  static const struct nand_controller_ops brcmnand_controller_ops = {
>  	.attach_chip = brcmnand_attach_chip,
> +	.exec_op = brcmnand_exec_op,
>  };
> 
>  static int brcmnand_init_cs(struct brcmnand_host *host,
> @@ -2846,13 +2780,6 @@ static int brcmnand_init_cs(struct brcmnand_host *host,
>  	mtd->owner = THIS_MODULE;
>  	mtd->dev.parent = dev;
> 
> -	chip->legacy.cmd_ctrl = brcmnand_cmd_ctrl;
> -	chip->legacy.cmdfunc = brcmnand_cmdfunc;
> -	chip->legacy.waitfunc = brcmnand_waitfunc;
> -	chip->legacy.read_byte = brcmnand_read_byte;
> -	chip->legacy.read_buf = brcmnand_read_buf;
> -	chip->legacy.write_buf = brcmnand_write_buf;
> -
>  	chip->ecc.engine_type = NAND_ECC_ENGINE_TYPE_ON_HOST;
>  	chip->ecc.read_page = brcmnand_read_page;
>  	chip->ecc.write_page = brcmnand_write_page;
> @@ -2864,6 +2791,7 @@ static int brcmnand_init_cs(struct brcmnand_host *host,
>  	chip->ecc.write_oob = brcmnand_write_oob;
> 
>  	chip->controller = &ctrl->controller;
> +	ctrl->controller.controller_wp = 1;
> 
>  	/*
>  	 * The bootloader might have configured 16bit mode but
> --
> 2.37.3
> 
> 


Thanks,
Miquèl

Hi Miquèl,

>
> Hello,
> 
> dregan@mail.com wrote on Thu, 12 Oct 2023 02:42:37 +0200:
> 

...

> > +
> > +int brcmnand_exec_op_is_status(const struct nand_operation *op)
> > +{
> > +	if ((op->instrs[0].type == NAND_OP_CMD_INSTR) &&
> > +		(op->instrs[0].ctx.cmd.opcode == NAND_CMD_STATUS) &&
> > +		(op->ninstrs > 1) &&
> > +		(op->instrs[1].type == NAND_OP_DATA_IN_INSTR))
> 
> You need to start checking if op->ninstrs == 2, no?

Will fix.

> 
> > +		return 1;
> > +
> > +	return 0;
> > +}
> > +
> > +int brcmnand_exec_op_is_reset(const struct nand_operation *op)
> > +{
> > +	if ((op->instrs[0].type == NAND_OP_CMD_INSTR) &&
> > +		(op->instrs[0].ctx.cmd.opcode == NAND_CMD_RESET))
> 
> Please check ninstrs as well (first).

Will do.

> 
> > +		return 1;
> > +
> > +	return 0;
> > +}
> > +
> > +static int brcmnand_exec_op(struct nand_chip *chip,
> > +			    const struct nand_operation *op,
> > +			    bool check_only)
> > +{
> > +	struct brcmnand_host *host = nand_get_controller_data(chip);
> > +	struct mtd_info *mtd = nand_to_mtd(chip);
> > +	const struct nand_op_instr *instr = &op->instrs[0];
> > +	u8 *status;
> > +	unsigned int i;
> > +	int ret = 0;
> > +
> > +	if (check_only)
> > +		return 0;
> > +
> > +	if (brcmnand_exec_op_is_status(op)) {
> > +		status = op->instrs[1].ctx.data.buf.in;
> > +		*status = brcmnand_status(host);
> > +
> > +		return 0;
> > +	}
> > +
> > +	if (op->deassert_wp)
> > +		brcmnand_wp(mtd, 0);
> > +
> > +	for (i = 0; i < op->ninstrs; i++) {
> > +		instr = &op->instrs[i];
> > +
> > +		if (instr->type == NAND_OP_WAITRDY_INSTR) {
> > +			ret = bcmnand_ctrl_poll_status(host, NAND_CTRL_RDY, NAND_CTRL_RDY, 0);
> 
> Why don't you handle this in brcmnand_exec_instr() ? It would look much
> nicer. Even if this does not involve any additional "cycle" on the NAND
> bus, it still is an instruction of the current operation.

Good idea.

> 
> > +			if (ret)
> > +				break;
> > +		} else { /* otherwise pass to low level implementation */
> > +			ret = brcmnand_exec_instr(host, instr, i == (op->ninstrs - 1));
> 
> What's the point of this i == op->ninstrs - 1 check?
> 

It's to let the controller know we are issuing the last command
in a series of commands. I may need to rework this as to moving
waitrdy into brcmnand_exec_instr


> > +			if (ret)
> > +				break;
> > +		}
> > +	}
> > +
> > +	if (op->deassert_wp)
> > +		brcmnand_wp(mtd, 1);
> > +
> > +	if (brcmnand_exec_op_is_reset(op)) {
> > +		brcmnand_status(host);
> > +		brcmnand_wp(mtd, 1);
> 
> This should be done right after the status check, no?
> 
> Anyway, I'm not sure I understand this. Why do you read the status and
> assert WP?

I read the status to fill the cached status, and reset the WP to
it's default state.

...

> Thanks,
> Miquèl
>

Thanks!

-Dave