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From: Naga Sureshkumar Relli <nagasure@xilinx.com>
To: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: "boris.brezillon@bootlin.com" <boris.brezillon@bootlin.com>,
	"richard@nod.at" <richard@nod.at>,
	"wmw2@infradead.org" <wmw2@infradead.org>,
	"computersforpeace@gmail.com" <computersforpeace@gmail.com>,
	"marek.vasut@gmail.com" <marek.vasut@gmail.com>,
	"f.fainelli@gmail.com" <f.fainelli@gmail.com>,
	"mmayer@broadcom.com" <mmayer@broadcom.com>,
	"rogerq@ti.com" <rogerq@ti.com>,
	"ladis@linux-mips.org" <ladis@linux-mips.org>,
	"ada@thorsis.com" <ada@thorsis.com>,
	"honghui.zhang@mediatek.com" <honghui.zhang@mediatek.com>,
	"linux-mtd@lists.infradead.org" <linux-mtd@lists.infradead.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"nagasureshkumarrelli@gmail.com" <nagasureshkumarrelli@gmail.com>
Subject: RE: [LINUX PATCH v9 4/4] mtd: rawnand: pl353: Add basic driver for arm pl353 smc nand interface
Date: Fri, 8 Jun 2018 12:23:45 +0000	[thread overview]
Message-ID: <MWHPR02MB26238A3344D0F611D8D6B0DAAF7B0@MWHPR02MB2623.namprd02.prod.outlook.com> (raw)
In-Reply-To: <20180607215949.58e2d15d@xps13>

Hi Miquel,

> -----Original Message-----
> From: Miquel Raynal [mailto:miquel.raynal@bootlin.com]
> Sent: Friday, June 8, 2018 1:30 AM
> To: Naga Sureshkumar Relli <nagasure@xilinx.com>
> Cc: boris.brezillon@bootlin.com; richard@nod.at; wmw2@infradead.org;
> computersforpeace@gmail.com; marek.vasut@gmail.com; f.fainelli@gmail.com;
> mmayer@broadcom.com; rogerq@ti.com; ladis@linux-mips.org; ada@thorsis.com;
> honghui.zhang@mediatek.com; linux-mtd@lists.infradead.org; linux-kernel@vger.kernel.org;
> nagasureshkumarrelli@gmail.com
> Subject: Re: [LINUX PATCH v9 4/4] mtd: rawnand: pl353: Add basic driver for arm pl353
> smc nand interface
> 
> Hi Naga,
> 
> This is a partial review, enough for this version, see below.
Ok, Thanks.

> 
> On Wed, 6 Jun 2018 13:19:42 +0530, Naga Sureshkumar Relli
> <naga.sureshkumar.relli@xilinx.com> wrote:
> 
> > Add driver for arm pl353 static memory controller nand interface with
> 
> s/nand/NAND/
Ok I will update.
> 
> > HW ECC support. This controller is used in xilinx zynq soc for
> > interfacing
> 
> s/HW/hardware/
Ok I will update.
> 
> > the nand flash memory.
> >
> > Signed-off-by: Naga Sureshkumar Relli
> > <naga.sureshkumar.relli@xilinx.com>
> > ---
> > Changes in v9:
> >  - Addressed the below comments given by Miquel
> >  - instead of using pl353_nand_write32, use directly writel_relaxed
> >  - Fixed check patch warnings
> >  - Renamed write_buf/read_buf to write_data_op/read_data_op
> >  - use BIT macro instead of 1 << nr
> >  - Use NAND_ROW_ADDR_3 flag
> >  - Use nand_wait_ready()
> >  - Removed swecc functions
> >  - Use address cycles as per size, instead of reading it from
> > Parameter page
> >  - Instead of writing too many patterns, use optional property Changes
> > in v8:
> >  - Added exec_op() implementation
> >  - Fixed the below v7 review comments
> >  - removed mtd_info from pl353_nand_info struct
> >  - Corrected ecc layout offsets
> >  - Added on-die ecc support
> > Changes in v7:
> >  - Currently not implemented the memclk rate adjustments. I will
> >    look into this later and once the basic driver is accepted.
> >  - Fixed GPL licence ident
> > Changes in v6:
> >  - Fixed the checkpatch.pl reported warnings
> >  - Using the address cycles information from the onfi param page
> >    earlier it is hardcoded to 5 in driver Changes in v5:
> >  - Configure the nand timing parameters as per the onfi spec Changes
> > in v4:
> >  - Updated the driver to sync with pl353_smc driver APIs Changes in
> > v3:
> >  - implemented the proper error codes
> >  - further breakdown this patch to multiple sets
> >  - added the controller and driver details to Documentation section
> >  - updated the licenece to GPLv2
> >  - reorganized the pl353_nand_ecc_init function Changes in v2:
> >  - use "depends on" rather than "select" option in kconfig
> >  - remove unused variable parts
> >  - remove dummy helper and use writel_relaxed directly
> > ---
> >
> >  drivers/mtd/nand/raw/Kconfig      |    7 +
> >  drivers/mtd/nand/raw/Makefile     |    3 +
> >  drivers/mtd/nand/raw/pl353_nand.c | 1236
> > +++++++++++++++++++++++++++++++++++++
> >  3 files changed, 1246 insertions(+)
> >  create mode 100644 drivers/mtd/nand/raw/pl353_nand.c
> >
> > diff --git a/drivers/mtd/nand/raw/Kconfig
> > b/drivers/mtd/nand/raw/Kconfig index 6871ff0..1c5d528 100644
> > --- a/drivers/mtd/nand/raw/Kconfig
> > +++ b/drivers/mtd/nand/raw/Kconfig
> > @@ -530,4 +530,11 @@ config MTD_NAND_MTK
> >  	  Enables support for NAND controller on MTK SoCs.
> >  	  This controller is found on mt27xx, mt81xx, mt65xx SoCs.
> >
> > +config MTD_NAND_PL353
> > +	tristate "ARM Pl353 NAND flash driver"
> > +	depends on MTD_NAND && ARM
> > +	depends on PL353_SMC
> > +	help
> > +	  Enables support for PrimeCell Static Memory Controller PL353.
> > +
> >  endif # MTD_NAND
> > diff --git a/drivers/mtd/nand/raw/Makefile
> > b/drivers/mtd/nand/raw/Makefile index 165b7ef..6855a0d 100644
> > --- a/drivers/mtd/nand/raw/Makefile
> > +++ b/drivers/mtd/nand/raw/Makefile
> > @@ -56,7 +56,9 @@ obj-$(CONFIG_MTD_NAND_HISI504)	        +=
> hisi504_nand.o
> >  obj-$(CONFIG_MTD_NAND_BRCMNAND)		+= brcmnand/
> >  obj-$(CONFIG_MTD_NAND_QCOM)		+= qcom_nandc.o
> >  obj-$(CONFIG_MTD_NAND_MTK)		+= mtk_ecc.o mtk_nand.o
> > +obj-$(CONFIG_MTD_NAND_PL353)		+= pl353_nand.o
> >
> > +CFLAGS_{nand_base.o} := -DDEBUG
> 
> Nope :)
For some reason I put this, I will remove this in next version.
> 
> >  nand-objs := nand_base.o nand_bbt.o nand_timings.o nand_ids.o
> > nand-objs += nand_amd.o  nand-objs += nand_hynix.o @@ -64,3 +66,4 @@
> > nand-objs += nand_macronix.o  nand-objs += nand_micron.o  nand-objs +=
> > nand_samsung.o  nand-objs += nand_toshiba.o
> > +
> 
> Extra space here
Ok I will update.
> 
> > diff --git a/drivers/mtd/nand/raw/pl353_nand.c
> > b/drivers/mtd/nand/raw/pl353_nand.c
> > new file mode 100644
> > index 0000000..a880eade
> > --- /dev/null
> > +++ b/drivers/mtd/nand/raw/pl353_nand.c
> > @@ -0,0 +1,1236 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * ARM PL353 NAND flash controller driver
> > + *
> > + * Copyright (C) 2017 Xilinx, Inc
> > + * Author: Punnaiah chowdary kalluri <punnaiah@xilinx.com>
> > + * Author: Naga Sureshkumar Relli <nagasure@xilinx.com>
> > + *
> > + */
> > +
> > +#include <linux/err.h>
> > +#include <linux/delay.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/io.h>
> > +#include <linux/ioport.h>
> > +#include <linux/irq.h>
> > +#include <linux/module.h>
> > +#include <linux/moduleparam.h>
> > +#include <linux/mtd/mtd.h>
> > +#include <linux/mtd/rawnand.h>
> > +#include <linux/mtd/nand_ecc.h>
> > +#include <linux/mtd/partitions.h>
> > +#include <linux/of_address.h>
> > +#include <linux/of_device.h>
> > +#include <linux/of_platform.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/slab.h>
> > +#include <linux/platform_data/pl353-smc.h>
> > +
> > +#define PL353_NAND_DRIVER_NAME "pl353-nand"
> > +
> > +/* NAND flash driver defines */
> > +#define PL353_NAND_CMD_PHASE	1	/* End command valid in command
> phase */
> > +#define PL353_NAND_DATA_PHASE	2	/* End command valid in data phase
> */
> > +#define PL353_NAND_ECC_SIZE	512	/* Size of data for ECC operation */
> > +
> > +/* Flash memory controller operating parameters */
> > +
> > +#define PL353_NAND_ECC_CONFIG	(BIT(4)  |	/* ECC read at end of page */
> \
> > +				 (0 << 5))	/* No Jumping */
> > +
> > +/* AXI Address definitions */
> > +#define START_CMD_SHIFT		3
> > +#define END_CMD_SHIFT		11
> > +#define END_CMD_VALID_SHIFT	20
> > +#define ADDR_CYCLES_SHIFT	21
> > +#define CLEAR_CS_SHIFT		21
> > +#define ECC_LAST_SHIFT		10
> > +#define COMMAND_PHASE		(0 << 19)
> > +#define DATA_PHASE		BIT(19)
> > +
> > +#define PL353_NAND_ECC_LAST	BIT(ECC_LAST_SHIFT)	/* Set
> ECC_Last */
> > +#define PL353_NAND_CLEAR_CS	BIT(CLEAR_CS_SHIFT)	/* Clear chip
> select */
> > +
> > +#define ONDIE_ECC_FEATURE_ADDR	0x90
> > +#define PL353_NAND_ECC_BUSY_TIMEOUT	(1 * HZ)
> > +#define PL353_NAND_DEV_BUSY_TIMEOUT	(1 * HZ)
> > +#define PL353_NAND_LAST_TRANSFER_LENGTH	4
> > +
> > +struct pl353_nfc_op {
> > +	u32 cmnds[4];
> > +	u32 thirdrow;
> > +	u32 type;
> > +	u32 end_cmd;
> > +	u32 addrs;
> > +	bool wait;
> > +	u32 len;
> > +	u32 naddrs;
> > +	unsigned int data_instr_idx;
> > +	const struct nand_op_instr *data_instr;
> > +	unsigned int rdy_timeout_ms;
> > +	unsigned int rdy_delay_ns;
> > +	unsigned int data_delay_ns;
> > +	unsigned int cle_ale_delay_ns;
> > +	u32 addr5;
> > +	u32 addr6;
> > +};
> > +
> > +/**
> > + * struct pl353_nand_info - Defines the NAND flash driver instance
> > + * @chip:		NAND chip information structure
> > + * @nand_base:		Virtual address of the NAND flash device
> > + * @end_cmd_pending:	End command is pending
> > + * @end_cmd:		End command
> > + * @row_addr_cycles:	Row address cycles
> > + * @col_addr_cycles:	Column address cycles
> > + * @address:		Page address
> > + * @cmd_pending:	More command is needed
> > + */
> > +struct pl353_nand_info {
> > +	struct nand_chip chip;
> > +	void __iomem *nand_base;
> > +	unsigned long end_cmd_pending;
> > +	unsigned long end_cmd;
> > +	u8 addr_cycles;
> > +	u32 address;
> > +	u32 cmd_pending;
> > +	struct completion complete;
> > +};
> > +
> > +static int pl353_ecc_ooblayout16_ecc(struct mtd_info *mtd, int section,
> > +				     struct mtd_oob_region *oobregion) {
> > +	struct nand_chip *chip = mtd_to_nand(mtd);
> > +
> > +	if (section >= chip->ecc.steps)
> > +		return -ERANGE;
> > +
> > +	oobregion->offset = (section * chip->ecc.bytes);
> > +	oobregion->length = chip->ecc.bytes;
> > +
> > +	return 0;
> > +}
> > +
> > +static int pl353_ecc_ooblayout16_free(struct mtd_info *mtd, int section,
> > +				      struct mtd_oob_region *oobregion) {
> > +	struct nand_chip *chip = mtd_to_nand(mtd);
> > +
> > +	if (section >= chip->ecc.steps)
> > +		return -ERANGE;
> > +
> > +	oobregion->offset = (section * chip->ecc.bytes) + 8;
> > +	oobregion->length = 8;
> > +
> > +	return 0;
> > +}
> > +
> > +static const struct mtd_ooblayout_ops pl353_ecc_ooblayout16_ops = {
> > +	.ecc = pl353_ecc_ooblayout16_ecc,
> > +	.free = pl353_ecc_ooblayout16_free,
> > +};
> > +
> > +static int pl353_ecc_ooblayout64_ecc(struct mtd_info *mtd, int section,
> > +				     struct mtd_oob_region *oobregion) {
> > +	struct nand_chip *chip = mtd_to_nand(mtd);
> > +
> > +	if (section >= chip->ecc.steps)
> > +		return -ERANGE;
> > +
> > +	oobregion->offset = (section * chip->ecc.bytes) + 52;
> > +	oobregion->length = chip->ecc.bytes;
> > +
> > +	return 0;
> > +}
> > +
> > +static int pl353_ecc_ooblayout64_free(struct mtd_info *mtd, int section,
> > +				      struct mtd_oob_region *oobregion) {
> > +	struct nand_chip *chip = mtd_to_nand(mtd);
> > +
> > +	if (section)
> > +		return -ERANGE;
> > +
> > +	if (section >= chip->ecc.steps)
> > +		return -ERANGE;
> > +
> > +	oobregion->offset = (section * chip->ecc.bytes) + 2;
> > +	oobregion->length = 50;
> > +
> > +	return 0;
> > +}
> > +
> > +static const struct mtd_ooblayout_ops pl353_ecc_ooblayout64_ops = {
> > +	.ecc = pl353_ecc_ooblayout64_ecc,
> > +	.free = pl353_ecc_ooblayout64_free,
> > +};
> > +
> > +/* Generic flash bbt decriptors */
> > +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 | NAND_BBT_PERCHIP,
> > +	.offs = 4,
> > +	.len = 4,
> > +	.veroffs = 20,
> > +	.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 | NAND_BBT_PERCHIP,
> > +	.offs = 4,
> > +	.len = 4,
> > +	.veroffs = 20,
> > +	.maxblocks = 4,
> > +	.pattern = mirror_pattern
> > +};
> > +
> > +/**
> > + * pl353_nand_read_data_op - read chip data into buffer
> > + * @chip:	Pointer to the NAND chip info structure
> > + * @in:		Pointer to the buffer to store read data
> > + * @len:	Number of bytes to read
> > + * Return:	Always return zero
> > + */
> > +static int pl353_nand_read_data_op(struct nand_chip *chip,
> > +				   u8 *in,
> > +				   unsigned int len)
> > +{
> > +	int i;
> > +
> > +	if (IS_ALIGNED((uint32_t)in, sizeof(uint32_t)) &&
> > +	    IS_ALIGNED(len, sizeof(uint32_t))) {
> > +		u32 *ptr = (u32 *)in;
> > +
> > +		len /= 4;
> > +		for (i = 0; i < len; i++)
> > +			ptr[i] = readl(chip->IO_ADDR_R);
> > +	} else {
> > +		for (i = 0; i < len; i++)
> > +			in[i] = readb(chip->IO_ADDR_R);
> 
> I'm not sure you need these IO_ADDR_R/W. Better not to use them in a new driver.
I am just continuing it from older driver. I will remove this in new driver
> 
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +/**
> > + * pl353_nand_write_buf - write buffer to chip
> > + * @mtd:	Pointer to the mtd info structure
> > + * @buf:	Pointer to the buffer to store write data
> > + * @len:	Number of bytes to write
> > + */
> > +static void pl353_nand_write_data_op(struct mtd_info *mtd, const u8 *buf,
> > +				     int len)
> > +{
> > +	int i;
> > +	struct nand_chip *chip = mtd_to_nand(mtd);
> > +
> > +	if (IS_ALIGNED((uint32_t)buf, sizeof(uint32_t)) &&
> > +	    IS_ALIGNED(len, sizeof(uint32_t))) {
> > +		u32 *ptr = (u32 *)buf;
> > +
> > +		len /= 4;
> > +		for (i = 0; i < len; i++)
> > +			writel(ptr[i], chip->IO_ADDR_W);
> > +	} else {
> > +		for (i = 0; i < len; i++)
> > +			writeb(buf[i], chip->IO_ADDR_W);
> > +	}
> > +}
> > +
> > +/**
> > + * pl353_nand_calculate_hwecc - Calculate Hardware ECC
> > + * @mtd:	Pointer to the mtd_info structure
> > + * @data:	Pointer to the page data
> > + * @ecc:	Pointer to the ECC buffer where ECC data needs to be stored
> > + *
> > + * This function retrieves the Hardware ECC data from the controller
> > +and returns
> > + * ECC data back to the MTD subsystem.
> > + *
> > + * Return:	0 on success or error value on failure
> > + */
> > +static int pl353_nand_calculate_hwecc(struct mtd_info *mtd,
> > +				      const u8 *data, u8 *ecc)
> > +{
> > +	u32 ecc_value, ecc_status;
> > +	u8 ecc_reg, ecc_byte;
> > +	unsigned long timeout = jiffies + PL353_NAND_ECC_BUSY_TIMEOUT;
> > +	/* Wait till the ECC operation is complete or timeout */
> > +	do {
> > +		if (pl353_smc_ecc_is_busy())
> > +			cpu_relax();
> > +		else
> > +			break;
> > +	} while (!time_after_eq(jiffies, timeout));
> > +
> > +	if (time_after_eq(jiffies, timeout)) {
> > +		pr_err("%s timed out\n", __func__);
> > +		return -ETIMEDOUT;
> > +	}
> > +
> > +	for (ecc_reg = 0; ecc_reg < 4; ecc_reg++) {
> 
> So here you hardcode the fact that there are 5 'blocks'. This is NAND chip dependent, right?
Yes. Not 5 but 4.

> 
> > +		/* Read ECC value for each block */
> > +		ecc_value = pl353_smc_get_ecc_val(ecc_reg);
> > +		ecc_status = (ecc_value >> 24) & 0xFF;
> 
> Please define all these values.
Ok I will update.
> 
> Make ecc_status a byte if you always need it to be 8-bit. Then you can drop the & 0xFF.
Ok I will update.
> 
> > +		/* ECC value valid */
> > +		if (ecc_status & 0x40) {
> 
> Please define this 0x40
Ok I will update.
> 
> > +			for (ecc_byte = 0; ecc_byte < 3; ecc_byte++) {
> > +				/* Copy ECC bytes to MTD buffer */
> > +				*ecc = ~ecc_value & 0xFF;
> 
> This is not a copy, you invert the bytes, I don't really know why.
> Perhaps a comment would be appreciated.

When programming NAND, the SMC controller adds an inversion of 
the ECC code if the number of ones is odd.
To match the hardware behavior, software should add an inversion of the ECC code.
I will add this in a comment.

> > +				ecc_value = ecc_value >> 8;
> > +				ecc++;
> > +			}
> > +		} else {
> > +			pr_warn("%s status failed\n", __func__);
> > +			return -1;
> > +		}
> > +	}
> > +	return 0;
> > +}
> > +
> > +/**
> > + * onehot - onehot function
> > + * @value:	Value to check for onehot
> > + *
> > + * This function checks whether a value is onehot or not.
> > + * onehot is if and only if onebit is set.
> > + *
> > + * Return:	1 if it is onehot else 0
> > + */
> > +static int onehot(unsigned short value)
> 
> Why not returning a boolean?
Yes. I will update it.

> > +{
> > +	return (value & (value - 1)) == 0;
> > +}
> > +
> > +/**
> > + * pl353_nand_correct_data - ECC correction function
> > + * @mtd:	Pointer to the mtd_info structure
> > + * @buf:	Pointer to the page data
> > + * @read_ecc:	Pointer to the ECC value read from spare data area
> > + * @calc_ecc:	Pointer to the calculated ECC value
> > + *
> > + * This function corrects the ECC single bit errors & detects 2-bit errors.
> > + *
> > + * Return:	0 if no ECC errors found
> > + *		1 if single bit error found and corrected.
> > + *		-1 if multiple ECC errors found.
> 
> "multiple uncorrectable ECC errors"
Ok, I will update

> 
> > + */
> > +static int pl353_nand_correct_data(struct mtd_info *mtd, unsigned char *buf,
> > +				   unsigned char *read_ecc,
> > +				   unsigned char *calc_ecc)
> > +{
> > +	unsigned char bit_addr;
> > +	unsigned int byte_addr;
> > +	unsigned short ecc_odd, ecc_even, read_ecc_lower, read_ecc_upper;
> > +	unsigned short calc_ecc_lower, calc_ecc_upper;
> > +
> > +	read_ecc_lower = (read_ecc[0] | (read_ecc[1] << 8)) & 0xfff;
> > +	read_ecc_upper = ((read_ecc[1] >> 4) | (read_ecc[2] << 4)) & 0xfff;
> > +
> > +	calc_ecc_lower = (calc_ecc[0] | (calc_ecc[1] << 8)) & 0xfff;
> > +	calc_ecc_upper = ((calc_ecc[1] >> 4) | (calc_ecc[2] << 4)) & 0xfff;
> > +
> > +	ecc_odd = read_ecc_lower ^ calc_ecc_lower;
> > +	ecc_even = read_ecc_upper ^ calc_ecc_upper;
> > +
> > +	/* no error */
> > +	if (ecc_odd == 0 && ecc_even == 0)
> 
> you can use "!ecc_odd && !ecc_even"
Ok I will update.

> 
> > +		return 0;
> > +
> > +	if (ecc_odd == (~ecc_even & 0xfff)) {
> > +		/* bits [11:3] of error code is byte offset */
> > +		byte_addr = (ecc_odd >> 3) & 0x1ff;
> > +		/* bits [2:0] of error code is bit offset */
> > +		bit_addr = ecc_odd & 0x7;
> > +		/* Toggling error bit */
> > +		buf[byte_addr] ^= (BIT(bit_addr));
> > +		return 1;
> > +	}
> > +	/* one error in parity */
> > +	if (onehot(ecc_odd | ecc_even) == 1)
> > +		return 1;
> > +
> > +	/* Uncorrectable error */
> > +	return -1;
> > +}
> > +
> > +static int pl353_dev_timeout(struct mtd_info *mtd, struct nand_chip
> > +*chip) {
> > +	unsigned long timeout = jiffies + PL353_NAND_DEV_BUSY_TIMEOUT;
> > +
> > +	do {
> > +		if (chip->dev_ready(mtd))
> > +			break;
> > +		cpu_relax();
> > +	} while (!time_after_eq(jiffies, timeout));
> > +
> > +	if (time_after_eq(jiffies, timeout)) {
> > +		pr_err("%s timed out\n", __func__);
> > +		return -1;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +static void pl353_prepare_cmd(struct mtd_info *mtd, struct nand_chip *chip,
> > +			      int page, int column, int start_cmd, int end_cmd,
> > +			      bool read)
> > +{
> > +	unsigned long data_phase_addr;
> > +	u32 end_cmd_valid = 0;
> > +	void __iomem *cmd_addr;
> > +	unsigned long cmd_phase_addr = 0, cmd_data = 0;
> > +
> > +	struct pl353_nand_info *xnand =
> > +		container_of(chip, struct pl353_nand_info, chip);
> > +
> > +	end_cmd_valid = read ? 1 : 0;
> > +
> > +	cmd_phase_addr = (unsigned long __force)xnand->nand_base +
> > +			 ((xnand->addr_cycles
> > +			 << ADDR_CYCLES_SHIFT) |
> > +			 (end_cmd_valid << END_CMD_VALID_SHIFT) |
> > +			 (COMMAND_PHASE) |
> > +			 (end_cmd << END_CMD_SHIFT) |
> > +			 (start_cmd << START_CMD_SHIFT));
> > +	cmd_addr = (void __iomem * __force)cmd_phase_addr;
> > +
> > +	/* Get the data phase address */
> > +	data_phase_addr = (unsigned long __force)xnand->nand_base +
> > +			  ((0x0 << CLEAR_CS_SHIFT) |
> > +			  (0 << END_CMD_VALID_SHIFT) |
> > +			  (DATA_PHASE) |
> > +			  (end_cmd << END_CMD_SHIFT) |
> > +			  (0x0 << ECC_LAST_SHIFT));
> > +
> > +	chip->IO_ADDR_R = (void __iomem * __force)data_phase_addr;
> > +	chip->IO_ADDR_W = chip->IO_ADDR_R;
> > +	if (chip->options & NAND_BUSWIDTH_16)
> > +		column /= 2;
> > +	cmd_data = column;
> > +	if (mtd->writesize > PL353_NAND_ECC_SIZE) {
> > +		cmd_data |= page << 16;
> > +		/* Another address cycle for devices > 128MiB */
> > +		if (chip->options & NAND_ROW_ADDR_3) {
> > +			writel_relaxed(cmd_data, cmd_addr);
> > +			cmd_data = (page >> 16);
> > +		}
> > +	} else {
> > +		cmd_data |= page << 8;
> > +	}
> > +
> > +	writel_relaxed(cmd_data, cmd_addr);
> > +}
> > +
> > +/**
> > + * pl353_nand_read_oob - [REPLACEABLE] the most common OOB data read function
> > + * @mtd:	Pointer to the mtd info structure
> > + * @chip:	Pointer to the NAND chip info structure
> > + * @page:	Page number to read
> > + *
> > + * Return:	Always return zero
> > + */
> > +static int pl353_nand_read_oob(struct mtd_info *mtd, struct nand_chip *chip,
> > +			       int page)
> > +{
> > +	unsigned long data_phase_addr;
> > +	u8 *p;
> > +	struct pl353_nand_info *xnand =
> > +		container_of(chip, struct pl353_nand_info, chip);
> > +	unsigned long nand_offset = (unsigned long __force)xnand->nand_base;
> > +
> > +	chip->pagebuf = -1;
> > +	if (mtd->writesize < PL353_NAND_ECC_SIZE)
> > +		return 0;
> > +
> > +	pl353_prepare_cmd(mtd, chip, page, mtd->writesize, NAND_CMD_READ0,
> > +			  NAND_CMD_READSTART, 1);
> > +
> > +	ndelay(100);
> > +	pl353_dev_timeout(mtd, chip);
> > +
> > +	p = chip->oob_poi;
> > +	pl353_nand_read_data_op(chip, p,
> > +				(mtd->oobsize -
> > +				PL353_NAND_LAST_TRANSFER_LENGTH));
> > +	p += (mtd->oobsize - PL353_NAND_LAST_TRANSFER_LENGTH);
> > +	data_phase_addr = (unsigned long __force)chip->IO_ADDR_R;
> > +	data_phase_addr -= nand_offset;
> > +	data_phase_addr |= PL353_NAND_CLEAR_CS;
> > +	data_phase_addr += nand_offset;
> > +	chip->IO_ADDR_R = (void __iomem * __force)data_phase_addr;
> > +	pl353_nand_read_data_op(chip, p, PL353_NAND_LAST_TRANSFER_LENGTH);
> > +
> > +	return 0;
> > +}
> > +
> > +/**
> > + * pl353_nand_write_oob - [REPLACEABLE] the most common OOB data write
> function
> > + * @mtd:	Pointer to the mtd info structure
> > + * @chip:	Pointer to the NAND chip info structure
> > + * @page:	Page number to write
> > + *
> > + * Return:	Zero on success and EIO on failure
> > + */
> > +static int pl353_nand_write_oob(struct mtd_info *mtd, struct nand_chip *chip,
> > +				int page)
> > +{
> > +	const u8 *buf = chip->oob_poi;
> > +	unsigned long data_phase_addr;
> > +	struct pl353_nand_info *xnand =
> > +		container_of(chip, struct pl353_nand_info, chip);
> > +	unsigned long nand_offset = (unsigned long __force)xnand->nand_base;
> > +	u32 addrcycles = 0;
> > +
> > +	chip->pagebuf = -1;
> > +	addrcycles = xnand->addr_cycles;
> > +	pl353_prepare_cmd(mtd, chip, page, mtd->writesize, NAND_CMD_SEQIN,
> > +			  NAND_CMD_PAGEPROG, 0);
> > +	ndelay(100);
> > +	pl353_nand_write_data_op(mtd, buf,
> > +				 (mtd->oobsize -
> > +				 PL353_NAND_LAST_TRANSFER_LENGTH));
> > +	buf += (mtd->oobsize - PL353_NAND_LAST_TRANSFER_LENGTH);
> > +
> > +	data_phase_addr = (unsigned long __force)chip->IO_ADDR_W;
> > +	data_phase_addr -= nand_offset;
> > +	data_phase_addr |= PL353_NAND_CLEAR_CS;
> > +	data_phase_addr |= (1 << END_CMD_VALID_SHIFT);
> > +	data_phase_addr += nand_offset;
> 
> What you do here is unclear and suspect...
> 
> > +	chip->IO_ADDR_W = (void __iomem * __force)data_phase_addr;
> > +	pl353_nand_write_data_op(mtd, buf,
> PL353_NAND_LAST_TRANSFER_LENGTH);
> > +	nand_wait_ready(mtd);
> > +
> > +	return 0;
> > +}
> > +
> > +/**
> > + * pl353_nand_read_page_raw - [Intern] read raw page data without ecc
> > + * @mtd:		Pointer to the mtd info structure
> > + * @chip:		Pointer to the NAND chip info structure
> > + * @buf:		Pointer to the data buffer
> > + * @oob_required:	Caller requires OOB data read to chip->oob_poi
> > + * @page:		Page number to read
> > + *
> > + * Return:	Always return zero
> > + */
> > +static int pl353_nand_read_page_raw(struct mtd_info *mtd,
> > +				    struct nand_chip *chip,
> > +				    u8 *buf, int oob_required, int page) {
> > +	unsigned long data_phase_addr;
> > +	u8 *p;
> > +	struct pl353_nand_info *xnand =
> > +		container_of(chip, struct pl353_nand_info, chip);
> > +	unsigned long nand_offset = (unsigned long __force)xnand->nand_base;
> > +
> > +	pl353_nand_read_data_op(chip, buf, mtd->writesize);
> > +	p = chip->oob_poi;
> > +	pl353_nand_read_data_op(chip, p,
> > +				(mtd->oobsize -
> > +				PL353_NAND_LAST_TRANSFER_LENGTH));
> > +	p += (mtd->oobsize - PL353_NAND_LAST_TRANSFER_LENGTH);
> > +
> > +	data_phase_addr = (unsigned long __force)chip->IO_ADDR_R;
> > +	data_phase_addr -= nand_offset;
> > +	data_phase_addr |= PL353_NAND_CLEAR_CS;
> > +	data_phase_addr += nand_offset;
> > +	chip->IO_ADDR_R = (void __iomem * __force)data_phase_addr;
> > +
> > +	pl353_nand_read_data_op(chip, p, PL353_NAND_LAST_TRANSFER_LENGTH);
> > +
> > +	return 0;
> > +}
> > +
> > +/**
> > + * pl353_nand_write_page_raw - [Intern] raw page write function
> > + * @mtd:		Pointer to the mtd info structure
> > + * @chip:		Pointer to the NAND chip info structure
> > + * @buf:		Pointer to the data buffer
> > + * @oob_required:	Caller requires OOB data read to chip->oob_poi
> > + * @page:		Page number to write
> > + *
> > + * Return:	Always return zero
> > + */
> > +static int pl353_nand_write_page_raw(struct mtd_info *mtd,
> > +				     struct nand_chip *chip,
> > +				     const u8 *buf, int oob_required,
> > +				     int page)
> > +{
> > +	unsigned long data_phase_addr;
> > +	u8 *p;
> > +
> > +	struct pl353_nand_info *xnand =
> > +		container_of(chip, struct pl353_nand_info, chip);
> > +	unsigned long nand_offset = (unsigned long __force)xnand->nand_base;
> > +
> > +	pl353_nand_write_data_op(mtd, buf, mtd->writesize);
> > +	p = chip->oob_poi;
> > +	pl353_nand_write_data_op(mtd, p,
> > +				 (mtd->oobsize -
> > +				 PL353_NAND_LAST_TRANSFER_LENGTH));
> > +	p += (mtd->oobsize - PL353_NAND_LAST_TRANSFER_LENGTH);
> > +
> > +	data_phase_addr = (unsigned long __force)chip->IO_ADDR_W;
> > +	data_phase_addr -= nand_offset;
> > +	data_phase_addr |= PL353_NAND_CLEAR_CS;
> > +	data_phase_addr |= (1 << END_CMD_VALID_SHIFT);
> > +	data_phase_addr += nand_offset;
> > +	chip->IO_ADDR_W = (void __iomem * __force)data_phase_addr;
> > +
> > +	pl353_nand_write_data_op(mtd, p, PL353_NAND_LAST_TRANSFER_LENGTH);
> > +	ndelay(100);
> > +	nand_wait_ready(mtd);
> > +	return 0;
> > +}
> > +
> > +/**
> > + * nand_write_page_hwecc - Hardware ECC based page write function
> > + * @mtd:		Pointer to the mtd info structure
> > + * @chip:		Pointer to the NAND chip info structure
> > + * @buf:		Pointer to the data buffer
> > + * @oob_required:	Caller requires OOB data read to chip->oob_poi
> > + * @page:		Page number to write
> > + *
> > + * This functions writes data and hardware generated ECC values in to the page.
> > + *
> > + * Return:	Always return zero
> > + */
> > +static int pl353_nand_write_page_hwecc(struct mtd_info *mtd,
> > +				       struct nand_chip *chip,
> > +				       const u8 *buf, int oob_required,
> > +				       int page)
> > +{
> > +	int eccsize = chip->ecc.size;
> > +	int eccsteps = chip->ecc.steps;
> > +	u8 *ecc_calc = chip->ecc.calc_buf;
> > +	u8 *oob_ptr;
> > +	const u8 *p = buf;
> > +	u32 ret;
> > +	unsigned long data_phase_addr;
> > +	struct pl353_nand_info *xnand =
> > +		container_of(chip, struct pl353_nand_info, chip);
> > +	unsigned long nand_offset = (unsigned long __force)xnand->nand_base;
> > +
> > +	pl353_prepare_cmd(mtd, chip, page, 0, NAND_CMD_SEQIN,
> > +			  NAND_CMD_PAGEPROG, 0);
> > +	ndelay(100);
> > +	for ( ; (eccsteps - 1); eccsteps--) {
> > +		pl353_nand_write_data_op(mtd, p, eccsize);
> > +		p += eccsize;
> > +	}
> > +	pl353_nand_write_data_op(mtd, p,
> > +				 (eccsize - PL353_NAND_LAST_TRANSFER_LENGTH));
> > +	p += (eccsize - PL353_NAND_LAST_TRANSFER_LENGTH);
> > +
> > +	/* Set ECC Last bit to 1 */
> > +	data_phase_addr = (unsigned long __force)chip->IO_ADDR_W;
> > +	data_phase_addr -= nand_offset;
> > +	data_phase_addr |= PL353_NAND_ECC_LAST;
> > +	data_phase_addr += nand_offset;
> > +	chip->IO_ADDR_W = (void __iomem * __force)data_phase_addr;
> > +	pl353_nand_write_data_op(mtd, p, PL353_NAND_LAST_TRANSFER_LENGTH);
> > +
> > +	p = buf;
> > +	chip->ecc.calculate(mtd, p, &ecc_calc[0]);
> > +
> > +	/* Wait for ECC to be calculated and read the error values */
> > +	ret = mtd_ooblayout_set_eccbytes(mtd, ecc_calc, chip->oob_poi,
> > +					 0, chip->ecc.total);
> > +	if (ret)
> > +		return ret;
> 
> Space
Will correct it.

> 
> > +	/* Clear ECC last bit */
> > +	data_phase_addr = (unsigned long __force)chip->IO_ADDR_W;
> > +	data_phase_addr -= nand_offset;
> > +	data_phase_addr &= ~PL353_NAND_ECC_LAST;
> > +	data_phase_addr += nand_offset;
> > +	chip->IO_ADDR_W = (void __iomem * __force)data_phase_addr;
> > +
> > +	/* Write the spare area with ECC bytes */
> > +	oob_ptr = chip->oob_poi;
> > +	pl353_nand_write_data_op(mtd, oob_ptr,
> > +				 (mtd->oobsize -
> > +				 PL353_NAND_LAST_TRANSFER_LENGTH));
> > +
> > +	data_phase_addr = (unsigned long __force)chip->IO_ADDR_W;
> > +	data_phase_addr -= nand_offset;
> > +	data_phase_addr |= PL353_NAND_CLEAR_CS;
> > +	data_phase_addr |= (1 << END_CMD_VALID_SHIFT);
> > +	data_phase_addr += nand_offset;
> > +	chip->IO_ADDR_W = (void __iomem * __force)data_phase_addr;
> > +	oob_ptr += (mtd->oobsize - PL353_NAND_LAST_TRANSFER_LENGTH);
> > +	pl353_nand_write_data_op(mtd, oob_ptr,
> > +PL353_NAND_LAST_TRANSFER_LENGTH);
> > +
> > +	/*
> > +	 * Apply this short delay always to ensure that we do wait tWB in any
> > +	 * case on any machine.
> > +	 */
> > +	ndelay(100);
> > +	nand_wait_ready(mtd);
> > +
> > +	return 0;
> > +}
> > +
> > +/**
> > + * pl353_nand_read_page_hwecc - Hardware ECC based page read function
> > + * @mtd:		Pointer to the mtd info structure
> > + * @chip:		Pointer to the NAND chip info structure
> > + * @buf:		Pointer to the buffer to store read data
> > + * @oob_required:	Caller requires OOB data read to chip->oob_poi
> > + * @page:		Page number to read
> > + *
> > + * This functions reads data and checks the data integrity by
> > +comparing hardware
> > + * generated ECC values and read ECC values from spare area.
> > + *
> > + * Return:	0 always and updates ECC operation status in to MTD structure
> > + */
> > +static int pl353_nand_read_page_hwecc(struct mtd_info *mtd,
> > +				      struct nand_chip *chip,
> > +				      u8 *buf, int oob_required, int page) {
> > +	int i, stat, eccsize = chip->ecc.size;
> > +	int eccbytes = chip->ecc.bytes;
> > +	int eccsteps = chip->ecc.steps;
> > +	u8 *p = buf;
> > +	u8 *ecc_calc = chip->ecc.calc_buf;
> > +	u8 *ecc = chip->ecc.code_buf;
> > +	unsigned int max_bitflips = 0;
> > +	u8 *oob_ptr;
> > +	u32 ret;
> > +	unsigned long data_phase_addr;
> > +	struct pl353_nand_info *xnand =
> > +		container_of(chip, struct pl353_nand_info, chip);
> > +	unsigned long nand_offset = (unsigned long __force)xnand->nand_base;
> > +
> > +	pl353_prepare_cmd(mtd, chip, page, 0, NAND_CMD_READ0,
> > +			  NAND_CMD_READSTART, 1);
> > +	ndelay(100);
> > +	pl353_dev_timeout(mtd, chip);
> > +
> > +	for ( ; (eccsteps - 1); eccsteps--) {
> > +		pl353_nand_read_data_op(chip, p, eccsize);
> > +		p += eccsize;
> > +	}
> > +	pl353_nand_read_data_op(chip, p,
> > +				(eccsize - PL353_NAND_LAST_TRANSFER_LENGTH));
> > +	p += (eccsize - PL353_NAND_LAST_TRANSFER_LENGTH);
> > +
> > +	/* Set ECC Last bit to 1 */
> > +	data_phase_addr = (unsigned long __force)chip->IO_ADDR_R;
> > +	data_phase_addr -= nand_offset;
> > +	data_phase_addr |= PL353_NAND_ECC_LAST;
> > +	data_phase_addr += nand_offset;
> > +	chip->IO_ADDR_R = (void __iomem * __force)data_phase_addr;
> > +	pl353_nand_read_data_op(chip, p, PL353_NAND_LAST_TRANSFER_LENGTH);
> > +
> > +	/* Read the calculated ECC value */
> > +	p = buf;
> > +	chip->ecc.calculate(mtd, p, &ecc_calc[0]);
> > +
> > +	/* Clear ECC last bit */
> > +	data_phase_addr = (unsigned long __force)chip->IO_ADDR_R;
> > +	data_phase_addr -= nand_offset;
> > +	data_phase_addr &= ~PL353_NAND_ECC_LAST;
> > +	data_phase_addr += nand_offset;
> > +	chip->IO_ADDR_R = (void __iomem * __force)data_phase_addr;
> > +
> > +	/* Read the stored ECC value */
> > +	oob_ptr = chip->oob_poi;
> > +	pl353_nand_read_data_op(chip, oob_ptr,
> > +				(mtd->oobsize -
> > +				PL353_NAND_LAST_TRANSFER_LENGTH));
> > +
> > +	/* de-assert chip select */
> > +	data_phase_addr = (unsigned long __force)chip->IO_ADDR_R;
> > +	data_phase_addr -= nand_offset;
> > +	data_phase_addr |= PL353_NAND_CLEAR_CS;
> > +	data_phase_addr += nand_offset;
> 
> Ok, now I am convinced this is not the right way. Please forget about
> chip->IO_ADDR_*.
Ok. I will update it.
> 
> > +	chip->IO_ADDR_R = (void __iomem * __force)data_phase_addr;
> > +
> > +	oob_ptr += (mtd->oobsize - PL353_NAND_LAST_TRANSFER_LENGTH);
> > +	pl353_nand_read_data_op(chip, oob_ptr,
> > +PL353_NAND_LAST_TRANSFER_LENGTH);
> > +
> > +	ret = mtd_ooblayout_get_eccbytes(mtd, ecc, chip->oob_poi, 0,
> > +					 chip->ecc.total);
> > +	if (ret)
> > +		return ret;
> > +
> > +	eccsteps = chip->ecc.steps;
> > +	p = buf;
> > +
> > +	/* Check ECC error for all blocks and correct if it is correctable */
> > +	for (i = 0 ; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
> > +		stat = chip->ecc.correct(mtd, p, &ecc[i], &ecc_calc[i]);
> > +		if (stat < 0) {
> > +			mtd->ecc_stats.failed++;
> > +		} else {
> > +			mtd->ecc_stats.corrected += stat;
> > +			max_bitflips = max_t(unsigned int, max_bitflips, stat);
> > +		}
> > +	}
> > +
> > +	return max_bitflips;
> > +}
> > +
> > +/**
> > + * pl353_nand_select_chip - Select the flash device
> > + * @mtd:	Pointer to the mtd info structure
> > + * @chip:	Pointer to the NAND chip info structure
> > + *
> > + * This function is empty as the NAND controller handles chip select
> > +line
> > + * internally based on the chip address passed in command and data phase.
> > + */
> > +static void pl353_nand_select_chip(struct mtd_info *mtd, int chip) {
> > +}
> > +
> > +/* NAND framework ->exec_op() hooks and related helpers */ static
> > +void pl353_nfc_parse_instructions(struct nand_chip *chip,
> > +					 const struct nand_subop *subop,
> > +					 struct pl353_nfc_op *nfc_op)
> > +{
> > +	const struct nand_op_instr *instr = NULL;
> > +	unsigned int op_id, offset, naddrs;
> > +	int i, len;
> > +	const u8 *addrs;
> > +
> > +	memset(nfc_op, 0, sizeof(struct pl353_nfc_op));
> > +	for (op_id = 0; op_id < subop->ninstrs; op_id++) {
> > +		nfc_op->len = nand_subop_get_data_len(subop, op_id);
> > +		len = nand_subop_get_data_len(subop, op_id);
> > +		instr = &subop->instrs[op_id];
> > +		if (subop->ninstrs == 1)
> > +			nfc_op->cmnds[0] = -1;
> > +		switch (instr->type) {
> > +		case NAND_OP_CMD_INSTR:
> > +			nfc_op->type = NAND_OP_CMD_INSTR;
> > +			if (op_id)
> > +				nfc_op->cmnds[1] = instr->ctx.cmd.opcode;
> > +			else
> > +				nfc_op->cmnds[0] = instr->ctx.cmd.opcode;
> > +			nfc_op->cle_ale_delay_ns = instr->delay_ns;
> > +			break;
> > +
> > +		case NAND_OP_ADDR_INSTR:
> > +			offset = nand_subop_get_addr_start_off(subop, op_id);
> > +			naddrs = nand_subop_get_num_addr_cyc(subop, op_id);
> > +			addrs = &instr->ctx.addr.addrs[offset];
> > +			nfc_op->addrs = instr->ctx.addr.addrs[offset];
> > +			for (i = 0; i < min_t(unsigned int, 4, naddrs); i++) {
> > +				nfc_op->addrs |= instr->ctx.addr.addrs[i] <<
> > +						 (8 * i);
> > +			}
> > +
> > +			if (naddrs >= 5)
> > +				nfc_op->addr5 = addrs[4];
> > +			if (naddrs >= 6)
> > +				nfc_op->addr6 = addrs[5];
> > +			nfc_op->naddrs = nand_subop_get_num_addr_cyc(subop,
> > +								     op_id);
> > +			nfc_op->cle_ale_delay_ns = instr->delay_ns;
> > +			break;
> > +
> > +		case NAND_OP_DATA_IN_INSTR:
> > +			nfc_op->data_instr = instr;
> > +			nfc_op->type = NAND_OP_DATA_IN_INSTR;
> > +			nfc_op->data_instr_idx = op_id;
> > +			nfc_op->data_delay_ns = instr->delay_ns;
> > +			break;
> > +
> > +		case NAND_OP_DATA_OUT_INSTR:
> > +			nfc_op->data_instr = instr;
> > +			nfc_op->type = NAND_OP_DATA_IN_INSTR;
> > +			nfc_op->data_instr_idx = op_id;
> > +			nfc_op->data_delay_ns = instr->delay_ns;
> > +			break;
> > +
> > +		case NAND_OP_WAITRDY_INSTR:
> > +			nfc_op->rdy_timeout_ms = instr->ctx.waitrdy.timeout_ms;
> > +			nfc_op->rdy_delay_ns = instr->delay_ns;
> > +			nfc_op->wait = true;
> > +			break;
> > +		}
> > +	}
> > +}
> > +
> > +static void cond_delay(unsigned int ns) {
> > +	if (!ns)
> > +		return;
> > +
> > +	if (ns < 10000)
> > +		ndelay(ns);
> > +	else
> > +		udelay(DIV_ROUND_UP(ns, 1000));
> > +}
> > +
> > +/**
> > + * pl353_nand_cmd_function - Send command to NAND device
> > + * @chip:	Pointer to the NAND chip info structure
> > + * @subop:	Pointer to array of instructions
> > + * Return:	Always return zero
> > + */
> > +static int pl353_nand_cmd_function(struct nand_chip *chip,
> > +				   const struct nand_subop *subop) {
> > +	struct mtd_info *mtd = nand_to_mtd(chip);
> > +	const struct nand_op_instr *instr;
> > +	struct pl353_nfc_op nfc_op = {};
> > +	struct pl353_nand_info *xnand =
> > +		container_of(chip, struct pl353_nand_info, chip);
> > +	void __iomem *cmd_addr;
> > +	unsigned long cmd_data = 0, end_cmd_valid = 0;
> > +	unsigned long cmd_phase_addr, data_phase_addr, end_cmd;
> > +	unsigned int op_id, len, offset;
> > +	bool reading;
> > +
> > +	pl353_nfc_parse_instructions(chip, subop, &nfc_op);
> > +	instr = nfc_op.data_instr;
> > +	op_id = nfc_op.data_instr_idx;
> > +	len = nand_subop_get_data_len(subop, op_id);
> > +	offset = nand_subop_get_data_start_off(subop, op_id);
> > +
> > +	if (nfc_op.cmnds[0] != -1) {
> > +		pl353_smc_clr_nand_int();
> > +		/* Get the command phase address */
> > +		if (nfc_op.cmnds[1] != 0) {
> > +			if (nfc_op.cmnds[0] == NAND_CMD_SEQIN)
> > +				end_cmd_valid = 0;
> > +			else
> > +				end_cmd_valid = 1;
> > +			end_cmd = nfc_op.cmnds[1];
> > +		}  else {
> > +			end_cmd = 0x0;
> > +		}
> > +		cmd_phase_addr = (unsigned long __force)xnand->nand_base +
> > +				 ((nfc_op.naddrs << ADDR_CYCLES_SHIFT) |
> > +				 (end_cmd_valid << END_CMD_VALID_SHIFT) |
> > +				 (COMMAND_PHASE) |
> > +				 (end_cmd << END_CMD_SHIFT) |
> > +				 (nfc_op.cmnds[0] << START_CMD_SHIFT));
> > +
> > +		cmd_addr = (void __iomem * __force)cmd_phase_addr;
> > +		/* Get the data phase address */
> > +		end_cmd_valid = 0;
> > +
> > +		data_phase_addr = (unsigned long __force)xnand->nand_base +
> > +				  ((0x0 << CLEAR_CS_SHIFT) |
> > +				  (end_cmd_valid << END_CMD_VALID_SHIFT) |
> > +				  (DATA_PHASE) |
> > +				  (end_cmd << END_CMD_SHIFT) |
> > +				  (0x0 << ECC_LAST_SHIFT));
> > +		chip->IO_ADDR_R = (void __iomem * __force)data_phase_addr;
> > +		chip->IO_ADDR_W = chip->IO_ADDR_R;
> > +		/* Command phase AXI Read & Write */
> > +		if (nfc_op.naddrs >= 5) {
> > +			if (mtd->writesize > PL353_NAND_ECC_SIZE) {
> > +				cmd_data = nfc_op.addrs;
> > +				/* Another address cycle for devices > 128MiB */
> > +				if (chip->options & NAND_ROW_ADDR_3) {
> > +					writel_relaxed(cmd_data, cmd_addr);
> > +					cmd_data = nfc_op.addr5;
> > +					if (nfc_op.naddrs >= 6)
> > +						cmd_data |= (nfc_op.addr6 << 8);
> > +				}
> > +			}
> > +		}  else {
> > +			if (nfc_op.addrs != -1) {
> > +				int column = nfc_op.addrs;
> > +				/*
> > +				 * Change read/write column, read id etc
> > +				 * Adjust columns for 16 bit bus width
> > +				 */
> > +				if ((chip->options & NAND_BUSWIDTH_16) &&
> > +				    (nfc_op.cmnds[0] == NAND_CMD_READ0 ||
> > +					nfc_op.cmnds[0] == NAND_CMD_SEQIN ||
> > +					nfc_op.cmnds[0] == NAND_CMD_RNDOUT ||
> > +					nfc_op.cmnds[0] == NAND_CMD_RNDIN)) {
> > +					column >>= 1;
> > +				}
> > +				cmd_data = column;
> > +			}
> > +		}
> > +		writel_relaxed(cmd_data, cmd_addr);
> > +	ndelay(100);
> > +	}
> > +
> > +	cond_delay(nfc_op.cle_ale_delay_ns);
> > +	if (!nfc_op.data_instr)
> > +		return 0;
> > +
> > +	reading = (nfc_op.data_instr->type == NAND_OP_DATA_IN_INSTR);
> > +	udelay(1000);
> 
> What is this delay ?
I tried removing this, But with out this delay the driver is throwing timeouts.
> 
> > +
> > +	if (!reading) {
> > +		cond_delay(nfc_op.rdy_delay_ns);
> > +
> > +		if (nfc_op.cmnds[0] == NAND_CMD_SEQIN &&
> > +		    nfc_op.cmnds[1] == NAND_CMD_PAGEPROG) {
> > +			pl353_nand_write_page_raw(mtd, chip,
> > +						  instr->ctx.data.buf.out, 0,
> > +						  nfc_op.addrs);
> > +		} else {
> > +			pl353_nand_write_data_op(mtd, instr->ctx.data.buf.out,
> > +						 len);
> > +		}
> > +	}
> > +
> > +	else if (reading) {
> > +		cond_delay(nfc_op.rdy_delay_ns);
> > +		pl353_nand_read_data_op(chip, instr->ctx.data.buf.in, len);
> > +	}
> > +	cond_delay(nfc_op.data_delay_ns);
> > +
> > +	return 0;
> > +}
> > +
> > +static const struct nand_op_parser pl353_nfc_op_parser = NAND_OP_PARSER
> > +	(NAND_OP_PARSER_PATTERN
> > +		(pl353_nand_cmd_function,
> > +		NAND_OP_PARSER_PAT_CMD_ELEM(true),
> > +		NAND_OP_PARSER_PAT_ADDR_ELEM(true, 7),
> > +		NAND_OP_PARSER_PAT_DATA_IN_ELEM(false, 2048)),
> > +	NAND_OP_PARSER_PATTERN
> > +		(pl353_nand_cmd_function,
> > +		NAND_OP_PARSER_PAT_CMD_ELEM(false),
> > +		NAND_OP_PARSER_PAT_ADDR_ELEM(false, 7),
> > +		NAND_OP_PARSER_PAT_CMD_ELEM(false),
> > +		NAND_OP_PARSER_PAT_WAITRDY_ELEM(false),
> > +		NAND_OP_PARSER_PAT_DATA_IN_ELEM(false, 2048)),
> > +	NAND_OP_PARSER_PATTERN
> > +		(pl353_nand_cmd_function,
> > +		NAND_OP_PARSER_PAT_CMD_ELEM(false),
> > +		NAND_OP_PARSER_PAT_ADDR_ELEM(true, 7),
> > +		NAND_OP_PARSER_PAT_CMD_ELEM(true),
> > +		NAND_OP_PARSER_PAT_WAITRDY_ELEM(false)),
> > +	NAND_OP_PARSER_PATTERN
> > +		(pl353_nand_cmd_function,
> > +		NAND_OP_PARSER_PAT_CMD_ELEM(false),
> > +		NAND_OP_PARSER_PAT_ADDR_ELEM(false, 8),
> > +		NAND_OP_PARSER_PAT_DATA_OUT_ELEM(false, 2048),
> > +		NAND_OP_PARSER_PAT_CMD_ELEM(true),
> > +		NAND_OP_PARSER_PAT_WAITRDY_ELEM(true)),
> > +	NAND_OP_PARSER_PATTERN
> > +		(pl353_nand_cmd_function,
> > +		NAND_OP_PARSER_PAT_CMD_ELEM(false)),
> > +	);
> > +
> > +static int pl353_nfc_exec_op(struct nand_chip *chip,
> > +			     const struct nand_operation *op,
> > +			     bool check_only)
> > +{
> > +	return nand_op_parser_exec_op(chip, &pl353_nfc_op_parser,
> > +					      op, check_only);
> > +}
> > +
> > +/**
> > + * pl353_nand_device_ready - Check device ready/busy line
> > + * @mtd:	Pointer to the mtd_info structure
> > + *
> > + * Return:	0 on busy or 1 on ready state
> > + */
> > +static int pl353_nand_device_ready(struct mtd_info *mtd) {
> > +	if (pl353_smc_get_nand_int_status_raw()) {
> > +		pl353_smc_clr_nand_int();
> 
> A clear is really needed here?
Yes, cfg_clr register is write only, so when ever an interrupt hits, then it needs to be cleared.
> 
> > +		return 1;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +/**
> > + * pl353_nand_ecc_init - Initialize the ecc information as per the ecc mode
> > + * @mtd:	Pointer to the mtd_info structure
> > + * @ecc:	Pointer to ECC control structure
> > + * @ecc_mode:	ondie ecc status
> > + *
> > + * This function initializes the ecc block and functional pointers as
> > +per the
> > + * ecc mode
> > + */
> > +static void pl353_nand_ecc_init(struct mtd_info *mtd, struct nand_ecc_ctrl *ecc,
> > +				int ecc_mode)
> > +{
> > +	struct nand_chip *chip = mtd_to_nand(mtd);
> > +	struct pl353_nand_info *xnand =
> > +		container_of(chip, struct pl353_nand_info, chip);
> > +
> > +
> > +	if (ecc_mode == NAND_ECC_ON_DIE) {
> > +		pl353_smc_set_ecc_mode(PL353_SMC_ECCMODE_BYPASS);
> > +		/*
> > +		 * On-Die ECC spare bytes offset 8 is used for ECC codes
> > +		 * Use the BBT pattern descriptors
> > +		 */
> > +		chip->bbt_td = &bbt_main_descr;
> > +		chip->bbt_md = &bbt_mirror_descr;
> > +		bitmap_set(chip->parameters.get_feature_list,
> > +			   ONFI_FEATURE_ON_DIE_ECC,
> ONFI_FEATURE_ON_DIE_ECC_EN);
> > +		bitmap_set(chip->parameters.set_feature_list,
> > +			   ONFI_FEATURE_ON_DIE_ECC,
> ONFI_FEATURE_ON_DIE_ECC_EN);
> > +	} else {
> > +		ecc->read_oob = pl353_nand_read_oob;
> > +		ecc->write_oob = pl353_nand_write_oob;
> > +
> > +		ecc->mode = NAND_ECC_HW;
> > +		/* Hardware ECC generates 3 bytes ECC code for each 512 bytes */
> > +		ecc->bytes = 3;
> > +		ecc->strength = 1;
> > +		ecc->calculate = pl353_nand_calculate_hwecc;
> 
> I'm not sure you need this calculate()...
The ECC calculation is specific to this controller, hence a separate hwecc calculation is needed.
> 
> > +		ecc->correct = pl353_nand_correct_data;
> > +		ecc->hwctl = NULL;
> 
> You can drop the line.
Ok, I will update in next version.
> 
> > +		ecc->read_page = pl353_nand_read_page_hwecc;
> > +		ecc->size = PL353_NAND_ECC_SIZE;
> > +		ecc->write_page = pl353_nand_write_page_hwecc;
> > +		pl353_smc_set_ecc_pg_size(mtd->writesize);
> > +		switch (mtd->writesize) {
> > +		case SZ_512:
> > +		case SZ_1K:
> > +		case SZ_2K:
> > +			pl353_smc_set_ecc_mode(PL353_SMC_ECCMODE_APB);
> > +			break;
> > +		default:
> > +			/*
> > +			 * The software ECC routines won't work with the
> > +			 * SMC controller
> > +			 */
> > +			ecc->calculate = nand_calculate_ecc;
> > +			ecc->correct = nand_correct_data;
> > +			ecc->size = 256;
> > +			break;
> > +		}
> > +		if (mtd->writesize <= SZ_512)
> > +			xnand->addr_cycles = 1;
> > +		else
> > +			xnand->addr_cycles = 2;
> > +
> > +		if (chip->options & NAND_ROW_ADDR_3)
> > +			xnand->addr_cycles += 3;
> > +		else
> > +			xnand->addr_cycles += 2;
> > +
> > +		if (mtd->oobsize == 16)
> > +			mtd_set_ooblayout(mtd, &pl353_ecc_ooblayout16_ops);
> > +		else if (mtd->oobsize == 64)
> > +			mtd_set_ooblayout(mtd, &pl353_ecc_ooblayout64_ops);
> 
> else?
You mean to say, add an error condition?
> 
> > +	}
> > +}
> > +
> > +/**
> > + * pl353_nand_probe - Probe method for the NAND driver
> > + * @pdev:	Pointer to the platform_device structure
> > + *
> > + * This function initializes the driver data structures and the hardware.
> > + *
> > + * Return:	0 on success or error value on failure
> > + */
> > +static int pl353_nand_probe(struct platform_device *pdev) {
> > +	struct pl353_nand_info *xnand;
> 
> xnand is a strange name, more and more because its a bout NAND controller data, not NAND
> chip.
We added this name to represent Xilinx Nand(xnand), 
> 
> > +	struct mtd_info *mtd;
> > +	struct nand_chip *nand_chip;
> 
> This one you can call it just "nand" or "chip".
Ok, I will update.

> 
> > +	struct resource *res;
> > +
> > +	xnand = devm_kzalloc(&pdev->dev, sizeof(*xnand), GFP_KERNEL);
> > +	if (!xnand)
> > +		return -ENOMEM;
> > +
> > +	/* Map physical address of NAND flash */
> > +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > +	xnand->nand_base = devm_ioremap_resource(&pdev->dev, res);
> > +	if (IS_ERR(xnand->nand_base))
> > +		return PTR_ERR(xnand->nand_base);
> > +
> > +	nand_chip = &xnand->chip;
> > +	mtd = nand_to_mtd(nand_chip);
> > +	nand_chip->exec_op = pl353_nfc_exec_op;
> > +	nand_set_controller_data(nand_chip, xnand);
> > +	mtd->priv = nand_chip;
> > +	mtd->owner = THIS_MODULE;
> > +	mtd->name = PL353_NAND_DRIVER_NAME;
> 
> A label property in the DT might overwrite this value.
Could you please explain a bit more ?

> 
> > +	nand_set_flash_node(nand_chip, pdev->dev.of_node);
> > +
> > +	/* Set address of NAND IO lines */
> > +	nand_chip->IO_ADDR_R = xnand->nand_base;
> > +	nand_chip->IO_ADDR_W = xnand->nand_base;
> > +	/* Set the driver entry points for MTD */
> > +	nand_chip->dev_ready = pl353_nand_device_ready;
> > +	nand_chip->select_chip = pl353_nand_select_chip;
> > +	/* If we don't set this delay driver sets 20us by default */
> > +	nand_chip->chip_delay = 30;
> 
> And why 30 is better?
Let me get back to you on this.
> 
> I suppose you mean the core, not the driver. The driver is this file.
Yes, I will update
> 
> > +
> > +	/* Set the device option and flash width */
> > +	nand_chip->options = NAND_BUSWIDTH_AUTO;
> > +	nand_chip->bbt_options = NAND_BBT_USE_FLASH;
> > +	platform_set_drvdata(pdev, xnand);
> > +
> > +	/* first scan to find the device and get the page size */
> > +	if (nand_scan_ident(mtd, 1, NULL)) {
> > +		dev_err(&pdev->dev, "nand_scan_ident for NAND failed\n");
> > +		return -ENXIO;
> > +	}
> > +	pl353_nand_ecc_init(mtd, &nand_chip->ecc, nand_chip->ecc.mode);
> > +	if (nand_chip->options & NAND_BUSWIDTH_16)
> > +		pl353_smc_set_buswidth(PL353_SMC_MEM_WIDTH_16);
> > +	/* second phase scan */
> > +	if (nand_scan_tail(mtd)) {
> > +		dev_err(&pdev->dev, "nand_scan_tail for NAND failed\n");
> > +		return -ENXIO;
> > +	}
> > +
> > +	mtd_device_register(mtd, NULL, 0);
> > +
> > +	return 0;
> > +}
> > +
> > +/**
> > + * pl353_nand_remove - Remove method for the NAND driver
> > + * @pdev:	Pointer to the platform_device structure
> > + *
> > + * This function is called if the driver module is being unloaded. It
> > +frees all
> > + * resources allocated to the device.
> > + *
> > + * Return:	0 on success or error value on failure
> > + */
> > +static int pl353_nand_remove(struct platform_device *pdev) {
> > +	struct pl353_nand_info *xnand = platform_get_drvdata(pdev);
> > +	struct mtd_info *mtd = nand_to_mtd(&xnand->chip);
> > +
> > +	/* Release resources, unregister device */
> > +	nand_release(mtd);
> > +
> > +	return 0;
> > +}
> > +
> > +/* Match table for device tree binding */ static const struct
> > +of_device_id pl353_nand_of_match[] = {
> > +	{ .compatible = "arm,pl353-nand-r2p1" },
> > +	{},
> > +};
> > +MODULE_DEVICE_TABLE(of, pl353_nand_of_match);
> > +
> > +/*
> > + * pl353_nand_driver - This structure defines the NAND subsystem
> > +platform driver  */ static struct platform_driver pl353_nand_driver =
> > +{
> > +	.probe		= pl353_nand_probe,
> > +	.remove		= pl353_nand_remove,
> > +	.driver		= {
> > +		.name	= PL353_NAND_DRIVER_NAME,
> > +		.of_match_table = pl353_nand_of_match,
> > +	},
> > +};
> > +
> > +module_platform_driver(pl353_nand_driver);
> > +
> > +MODULE_AUTHOR("Xilinx, Inc.");
> > +MODULE_ALIAS("platform:" PL353_NAND_DRIVER_NAME);
> > +MODULE_DESCRIPTION("ARM PL353 NAND Flash Driver");
> > +MODULE_LICENSE("GPL");
> 
> Thanks,
> Miquèl
> 
> --
> Miquel Raynal, Bootlin (formerly Free Electrons) Embedded Linux and Kernel engineering
> https://bootlin.com

Thanks,
Naga Sureshkumar Relli.

  reply	other threads:[~2018-06-08 12:24 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-06-06  7:49 [LINUX PATCH v9 0/4] Add arm pl353 smc memory and nand driver for xilinx zynq soc Naga Sureshkumar Relli
2018-06-06  7:49 ` [LINUX PATCH v9 1/4] Devicetree: Add pl353 smc controller devicetree binding information Naga Sureshkumar Relli
2018-06-07 15:42   ` Miquel Raynal
2018-06-07 15:47     ` Miquel Raynal
2018-06-08  5:20     ` Naga Sureshkumar Relli
2018-06-08  5:51       ` Boris Brezillon
2018-06-08  8:01         ` Naga Sureshkumar Relli
2018-06-08  7:23       ` Miquel Raynal
2018-06-06  7:49 ` [LINUX PATCH v9 2/4] memory: pl353: Add driver for arm pl353 static memory controller Naga Sureshkumar Relli
2018-06-07 16:07   ` Miquel Raynal
2018-06-19 10:54     ` Naga Sureshkumar Relli
2018-06-06  7:49 ` [LINUX PATCH v9 3/4] Documentation: nand: pl353: Add documentation for controller and driver Naga Sureshkumar Relli
2018-06-06  7:49 ` [LINUX PATCH v9 4/4] mtd: rawnand: pl353: Add basic driver for arm pl353 smc nand interface Naga Sureshkumar Relli
2018-06-07 19:59   ` Miquel Raynal
2018-06-08 12:23     ` Naga Sureshkumar Relli [this message]
2018-06-08 12:35       ` Miquel Raynal
2018-06-08 13:08         ` Naga Sureshkumar Relli

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