[U-Boot] [PATCH v2 1/2] mtd/spi: Add JEDEC SFDP support in SPI framework

Rajat Srivastava rajat.srivastava at nxp.com
Fri Nov 16 09:40:42 UTC 2018



> -----Original Message-----
> From: Vignesh R <vigneshr at ti.com>
> Sent: Thursday, November 15, 2018 2:52 PM
> To: Rajat Srivastava <rajat.srivastava at nxp.com>; u-boot at lists.denx.de
> Cc: jagan at openedev.com
> Subject: Re: [U-Boot] [PATCH v2 1/2] mtd/spi: Add JEDEC SFDP support in SPI
> framework
> 
> Hi Rajat,
> 
> On 13/11/18 5:30 PM, Rajat Srivastava wrote:
> > Add support for JESD216 rev B standard JEDEC Serial Flash Discoverable
> > Parameters (SFDP) tables to dynamically initialize flash size, page
> > size and address width of the flash. More parameters can be added as
> > per requirement.
> > SFDP parsing is made default but already existing method for parsing
> > these parameters are not deprecated.
> > A flag is created to skip SFDP parsing for a particular flash, if
> > required.
> >
> > SFDP data lets us auto-detect the addressing mode supported by the
> > flash which helps us access the flash using 4-byte address.
> >
> > Add a new argument in spi_flash_addr() function to create commands
> > with 3-byte or 4-byte address depending on the SFDP data read. Add
> > pointer to struct spi_flash in struct spi_slave so that driver can
> > have access to SFDP data.
> >
> > Introduce new structures and functions to read and parse SFDP data.
> > This is loosely based on Linux SFDP framework.
> >
> > Signed-off-by: Rajat Srivastava <rajat.srivastava at nxp.com>
> > ---
> > Changes in v2:
> > - Make SFDP parsing the default method.
> > - Change SPI_FLASH_USE_SFDP flag to SPI_FLASH_USE_SFDP to provide an
> > option to skip SFDP parsing for a particular flash.
> > ---
> 
> [...]
> > +static int spi_flash_parse_bfpt(struct spi_flash *flash,
> > +				const struct sfdp_parameter_header
> *bfpt_header) {
> > +	struct sfdp_bfpt bfpt;
> > +	size_t len;
> > +	int i, err;
> > +	u32 addr;
> > +
> > +	/* JESD216 Basic Flash Parameter Table length is at least 9 DWORDs.
> */
> > +	if (bfpt_header->length < BFPT_DWORD_MAX_JESD216)
> > +		return -EINVAL;
> > +
> > +	/* Read the Basic Flash Parameter Table. */
> > +	len = min_t(size_t, sizeof(bfpt),
> > +		    bfpt_header->length * sizeof(u32));
> > +	addr = SFDP_PARAM_HEADER_PTP(bfpt_header);
> > +	memset(&bfpt, 0, sizeof(bfpt));
> > +	err = spi_flash_read_sfdp(flash, addr, len, &bfpt);
> > +	if (err < 0)
> > +		return err;
> > +
> > +	/* Fix endianness of the BFPT DWORDs. */
> > +	for (i = 0; i < BFPT_DWORD_MAX; i++)
> > +		bfpt.dwords[i] = le32_to_cpu(bfpt.dwords[i]);
> > +
> > +	/* Number of address bytes. */
> > +	switch (bfpt.dwords[BFPT_DWORD(1)] &
> BFPT_DWORD1_ADDRESS_BYTES_MASK) {
> > +	case BFPT_DWORD1_ADDRESS_BYTES_3_ONLY:
> > +		flash->addr_width = 3;
> > +		break;
> > +
> > +	case BFPT_DWORD1_ADDRESS_BYTES_3_OR_4:
> > +		printf("SF: Flash defaults to 3-Byte mode; enters 4-Byte ");
> > +		printf("mode on command\n");
> > +		/*
> > +		 * By default, 4-byte addressing mode is set.
> > +		 * To enforce 3-byte addressing mode, set addrwd_3_in_use
> flag
> > +		 * in struct spi_flash for every command.
> > +		 */
> > +		flash->addr_width = 4;
> > +		break;
> > +
> > +	case BFPT_DWORD1_ADDRESS_BYTES_4_ONLY:
> > +		flash->addr_width = 4;
> > +		break;
> > +
> 
> I see your are updating flash->addr_width to 4 bytes here. But I don't see
> any code in this patch that changes flash->read_cmd (and write/erase
> cmds) to use 4B addressing opcodes. Also, I dont see any code that bypasses
> BAR register configuration when CONFIG_SPI_FLASH_BAR is defined and
> SFDP is available.

We don't have any flash that supports CONFIG_SPI_FLASH_BAR. What do you suggest, shall we skip SFDP parsing in case CONFIG_SPI_FLASH_BAR is defined?

> This patch will most certainly break SPI controller drivers(like
> cadence_qspi.c) that expect sf layer to provide correct read opcode and
> address width information, since there will be mismatch wrt opcode used
> and number of address byte sent.
> Not sure how this patch was tested, but I guess fsl_qspi modifies read
> opcode internal to the driver and gets away with it.
> Please modify the patch to update read_cmd/erase_cmd/write_cmd to use
> 4 byte addressing opcodes

If the flash supports only supports 4-byte opcodes then there will be no mismatch 
wrt opcode used and number of address bytes sent since all of the opcodes that 
the flash supports will be 4-bytes opcodes.
But if the flash supports both 3-byte as well as 4-byte address widths (which is a 
separate case) then this code will default the address mode to 4-byte but gives an 
option to use 3-byte by setting addrwd_3_in_use flag.

Regards
Rajat

> 
> Regards
> Vigensh
> 
> 
> > +	default:
> > +		break;
> > +	}
> > +
> > +	/* Flash Memory Density (in bits). */
> > +	flash->size = bfpt.dwords[BFPT_DWORD(2)];
> > +	if (flash->size & BIT(31)) {
> > +		flash->size &= ~BIT(31);
> > +
> > +		/*
> > +		 * Prevent overflows on flash->size. Anyway, a NOR of 2^64
> > +		 * bits is unlikely to exist so this error probably means
> > +		 * the BFPT we are reading is corrupted/wrong.
> > +		 */
> > +		if (flash->size > 63)
> > +			return -EINVAL;
> > +
> > +		flash->size = 1ULL << flash->size;
> > +	} else {
> > +		flash->size++;
> > +	}
> > +	flash->size >>= 3; /* Convert to bytes. */
> > +
> > +	/* Stop here if not JESD216 rev A or later. */
> > +	if (bfpt_header->length < BFPT_DWORD_MAX)
> > +		return 0;
> > +
> > +	/* Page size: this field specifies 'N' so the page size = 2^N bytes. */
> > +	flash->page_size = bfpt.dwords[BFPT_DWORD(11)];
> > +	flash->page_size &= BFPT_DWORD11_PAGE_SIZE_MASK;
> > +	flash->page_size >>= BFPT_DWORD11_PAGE_SIZE_SHIFT;
> > +	flash->page_size = 1U << flash->page_size;
> > +
> > +	return 0;
> > +}
> > +
> > +/*
> > + * spi_flash_parse_sfdp() - parse the Serial Flash Discoverable
> Parameters.
> > + * @flash:	pointer to a 'struct spi_flash'
> > + *
> > + * The Serial Flash Discoverable Parameters are described by the
> > +JEDEC JESD216
> > + * specification. This is a standard which tends to supported by
> > +almost all
> > + * (Q)SPI memory manufacturers. Those hard-coded tables allow us to
> > +learn at
> > + * runtime the main parameters needed to perform basic SPI flash
> operations.
> > + *
> > + * Return: 0 on success, -errno otherwise.
> > + */
> > +static int spi_flash_parse_sfdp(struct spi_flash *flash) {
> > +	const struct sfdp_parameter_header *param_header,
> *bfpt_header;
> > +	struct sfdp_parameter_header *param_headers = NULL;
> > +	struct sfdp_header header;
> > +	size_t psize;
> > +	int i, err;
> > +
> > +	/* Get the SFDP header. */
> > +	err = spi_flash_read_sfdp(flash, 0, sizeof(header), &header);
> > +	if (err < 0)
> > +		return err;
> > +
> > +	/* Check the SFDP header version. */
> > +	if (le32_to_cpu(header.signature) != SFDP_SIGNATURE ||
> > +	    header.major != SFDP_JESD216_MAJOR)
> > +		return -EINVAL;
> > +
> > +	/*
> > +	 * Verify that the first and only mandatory parameter header is a
> > +	 * Basic Flash Parameter Table header as specified in JESD216.
> > +	 */
> > +	bfpt_header = &header.bfpt_header;
> > +	if (SFDP_PARAM_HEADER_ID(bfpt_header) != SFDP_BFPT_ID ||
> > +	    bfpt_header->major != SFDP_JESD216_MAJOR)
> > +		return -EINVAL;
> > +
> > +	/*
> > +	 * Allocate memory then read all parameter headers with a single
> > +	 * Read SFDP command. These parameter headers will actually be
> parsed
> > +	 * twice: a first time to get the latest revision of the basic flash
> > +	 * parameter table, then a second time to handle the supported
> optional
> > +	 * tables.
> > +	 * Hence we read the parameter headers once for all to reduce the
> > +	 * processing time
> > +	 */
> > +	if (header.nph) {
> > +		psize = header.nph * sizeof(*param_headers);
> > +
> > +		param_headers = malloc(psize);
> > +		if (!param_headers)
> > +			return -ENOMEM;
> > +
> > +		err = spi_flash_read_sfdp(flash, sizeof(header),
> > +					  psize, param_headers);
> > +		if (err < 0) {
> > +			dev_err(dev, "failed to read SFDP parameter
> headers\n");
> > +			goto exit;
> > +		}
> > +	}
> > +
> > +	/*
> > +	 * Check other parameter headers to get the latest revision of
> > +	 * the basic flash parameter table.
> > +	 */
> > +	for (i = 0; i < header.nph; i++) {
> > +		param_header = &param_headers[i];
> > +
> > +		if (SFDP_PARAM_HEADER_ID(param_header) ==
> SFDP_BFPT_ID &&
> > +		    param_header->major == SFDP_JESD216_MAJOR &&
> > +		    (param_header->minor > bfpt_header->minor ||
> > +		     (param_header->minor == bfpt_header->minor &&
> > +		      param_header->length > bfpt_header->length)))
> > +			bfpt_header = param_header;
> > +	}
> > +
> > +	err = spi_flash_parse_bfpt(flash, bfpt_header);
> > +	if (err)
> > +		goto exit;
> > +
> > +exit:
> > +	free(param_headers);
> > +	return err;
> > +}
> > +
> >  static int set_quad_mode(struct spi_flash *flash,
> >  			 const struct spi_flash_info *info)  { @@ -1130,7
> +1366,7 @@ int
> > spi_flash_scan(struct spi_flash *flash)  {
> >  	struct spi_slave *spi = flash->spi;
> >  	const struct spi_flash_info *info = NULL;
> > -	int ret;
> > +	int ret, sfdp = 0;
> >
> >  	info = spi_flash_read_id(flash);
> >  	if (IS_ERR_OR_NULL(info))
> > @@ -1196,9 +1432,28 @@ int spi_flash_scan(struct spi_flash *flash)
> >  	}
> >  #endif
> >
> > +	spi->flash = flash;
> > +	flash->addrwd_3_in_use = false;
> > +
> > +	/* Read Serial Flash Discoverable Parameters and initialize
> > +	 * the following parameters of flash:
> > +	 * 1. Flash size
> > +	 * 2. Page size
> > +	 * 3. Address width to be used for commands
> > +	 */
> > +	if (!(info->flags & SPI_FLASH_SKIP_SFDP)) {
> > +		flash->size = 0;
> > +		sfdp = spi_flash_parse_sfdp(flash);
> > +		if (sfdp < 0)
> > +			debug("Unable to get SFDP information\n");
> > +	}
> > +
> >  	/* Compute the flash size */
> >  	flash->shift = (flash->dual_flash & SF_DUAL_PARALLEL_FLASH) ? 1 :
> 0;
> > -	flash->page_size = info->page_size;
> > +	if (info->flags & SPI_FLASH_SKIP_SFDP || sfdp < 0) {
> > +		flash->page_size = info->page_size;
> > +		flash->addr_width = SPI_FLASH_3B_ADDR_LEN;
> > +	}
> >  	/*
> >  	 * The Spansion S25FS512S, S25FL032P and S25FL064P have 256b
> pages,
> >  	 * yet use the 0x4d00 Extended JEDEC code. The rest of the Spansion
> > @@ -1213,7 +1468,10 @@ int spi_flash_scan(struct spi_flash *flash)
> >  	}
> >  	flash->page_size <<= flash->shift;
> >  	flash->sector_size = info->sector_size << flash->shift;
> > -	flash->size = flash->sector_size * info->n_sectors << flash->shift;
> > +	if (info->flags & SPI_FLASH_SKIP_SFDP || sfdp < 0) {
> > +		flash->size = flash->sector_size * info->n_sectors <<
> > +			flash->shift;
> > +	}
> >  #ifdef CONFIG_SF_DUAL_FLASH
> >  	if (flash->dual_flash & SF_DUAL_STACKED_FLASH)
> >  		flash->size <<= 1;
> > @@ -1312,9 +1570,10 @@ int spi_flash_scan(struct spi_flash *flash)
> > #endif
> >
> >  #ifndef CONFIG_SPI_FLASH_BAR
> > -	if (((flash->dual_flash == SF_SINGLE_FLASH) &&
> > -	     (flash->size > SPI_FLASH_16MB_BOUN)) ||
> > -	     ((flash->dual_flash > SF_SINGLE_FLASH) &&
> > +	if ((info->flags & SPI_FLASH_SKIP_SFDP || sfdp < 0) &&
> > +	    (flash->dual_flash == SF_SINGLE_FLASH &&
> > +	     flash->size > SPI_FLASH_16MB_BOUN) ||
> > +	     (flash->dual_flash > SF_SINGLE_FLASH &&
> >  	     (flash->size > SPI_FLASH_16MB_BOUN << 1))) {
> >  		puts("SF: Warning - Only lower 16MiB accessible,");
> >  		puts(" Full access #define CONFIG_SPI_FLASH_BAR\n"); diff -
> -git
> > a/include/spi.h b/include/spi.h index 938627bc01..7189e60581 100644
> > --- a/include/spi.h
> > +++ b/include/spi.h
> > @@ -10,6 +10,7 @@
> >  #define _SPI_H_
> >
> >  #include <common.h>
> > +#include <spi_flash.h>
> >
> >  /* SPI mode flags */
> >  #define SPI_CPHA	BIT(0)			/* clock phase */
> > @@ -103,6 +104,7 @@ struct spi_slave {
> >  	unsigned int bus;
> >  	unsigned int cs;
> >  #endif
> > +	struct spi_flash *flash;
> >  	uint mode;
> >  	unsigned int wordlen;
> >  	unsigned int max_read_size;
> > diff --git a/include/spi_flash.h b/include/spi_flash.h index
> > 0ec98fb55d..6558a4a1d5 100644
> > --- a/include/spi_flash.h
> > +++ b/include/spi_flash.h
> > @@ -47,6 +47,9 @@ struct spi_slave;
> >   * @read_cmd:		Read cmd - Array Fast, Extn read and quad
> read.
> >   * @write_cmd:		Write cmd - page and quad program.
> >   * @dummy_byte:		Dummy cycles for read operation.
> > + * @cmd_len:		Total length of command.
> > + * @addr_width:		Number of address bytes.
> > + * @addrwd_3_in_use:	Flag to send command in 3-byte address
> mode.
> >   * @memory_map:		Address of read-only SPI flash access
> >   * @flash_lock:		lock a region of the SPI Flash
> >   * @flash_unlock:	unlock a region of the SPI Flash
> > @@ -82,6 +85,9 @@ struct spi_flash {
> >  	u8 read_cmd;
> >  	u8 write_cmd;
> >  	u8 dummy_byte;
> > +	u8 cmd_len;
> > +	u8 addr_width;
> > +	bool addrwd_3_in_use;
> >
> >  	void *memory_map;
> >
> > @@ -107,6 +113,120 @@ struct spi_flash {  #endif  };
> >
> > +/*
> > + * Serial Flash Discoverable Parameter Headers  */ struct
> > +sfdp_parameter_header {
> > +	u8	id_lsb;
> > +	u8	minor;
> > +	u8	major;
> > +	u8	length; /* in double words */
> > +	u8	parameter_table_pointer[3]; /* byte address */
> > +	u8	id_msb;
> > +};
> > +
> > +struct sfdp_header {
> > +	u32	signature; /* Ox50444653U <=> "SFDP" */
> > +	u8	minor;
> > +	u8	major;
> > +	u8	nph; /* 0-base number of parameter headers */
> > +	u8	unused;
> > +
> > +	/* Basic Flash Parameter Table. */
> > +	struct sfdp_parameter_header	bfpt_header;
> > +};
> > +
> > +#define SFDP_PARAM_HEADER_ID(p) (((p)->id_msb << 8) | (p)->id_lsb)
> > +#define SFDP_PARAM_HEADER_PTP(p) \
> > +	(((p)->parameter_table_pointer[2] << 16) | \
> > +	 ((p)->parameter_table_pointer[1] <<  8) | \
> > +	 ((p)->parameter_table_pointer[0] <<  0))
> > +
> > +#define SFDP_BFPT_ID		0xff00  /* Basic Flash Parameter Table
> */
> > +#define SFDP_SECTOR_MAP_ID	0xff81  /* Sector Map Table */
> > +
> > +#define SFDP_SIGNATURE		0x50444653U
> > +#define SFDP_JESD216_MAJOR	1
> > +#define SFDP_JESD216_MINOR	0
> > +#define SFDP_JESD216A_MINOR	5
> > +#define SFDP_JESD216B_MINOR	6
> > +
> > +/* Basic Flash Parameter Table */
> > +
> > +/*
> > + * JESD216 rev B defines a Basic Flash Parameter Table of 16 DWORDs.
> > + * They are indexed from 1 but C arrays are indexed from 0.
> > + */
> > +#define BFPT_DWORD(i)		((i) - 1)
> > +#define BFPT_DWORD_MAX		16
> > +
> > +/* The first version of JESB216 defined only 9 DWORDs. */
> > +#define BFPT_DWORD_MAX_JESD216			9
> > +
> > +/* 1st DWORD. */
> > +#define BFPT_DWORD1_FAST_READ_1_1_2		BIT(16)
> > +#define BFPT_DWORD1_ADDRESS_BYTES_MASK
> 	GENMASK(18, 17)
> > +#define BFPT_DWORD1_ADDRESS_BYTES_3_ONLY	(0x0UL << 17)
> > +#define BFPT_DWORD1_ADDRESS_BYTES_3_OR_4	(0x1UL << 17)
> > +#define BFPT_DWORD1_ADDRESS_BYTES_4_ONLY	(0x2UL << 17)
> > +#define BFPT_DWORD1_DTR				BIT(19)
> > +#define BFPT_DWORD1_FAST_READ_1_2_2		BIT(20)
> > +#define BFPT_DWORD1_FAST_READ_1_4_4		BIT(21)
> > +#define BFPT_DWORD1_FAST_READ_1_1_4		BIT(22)
> > +
> > +/* 5th DWORD. */
> > +#define BFPT_DWORD5_FAST_READ_2_2_2		BIT(0)
> > +#define BFPT_DWORD5_FAST_READ_4_4_4		BIT(4)
> > +
> > +/* 11th DWORD. */
> > +#define BFPT_DWORD11_PAGE_SIZE_SHIFT		4
> > +#define BFPT_DWORD11_PAGE_SIZE_MASK		GENMASK(7,
> 4)
> > +
> > +/* 15th DWORD. */
> > +
> > +/*
> > + * (from JESD216 rev B)
> > + * Quad Enable Requirements (QER):
> > + * - 000b: Device does not have a QE bit. Device detects 1-1-4 and 1-4-4
> > + *         reads based on instruction. DQ3/HOLD# functions are hold during
> > + *         instruction phase.
> > + * - 001b: QE is bit 1 of status register 2. It is set via Write Status with
> > + *         two data bytes where bit 1 of the second byte is one.
> > + *         [...]
> > + *         Writing only one byte to the status register has the side-effect of
> > + *         clearing status register 2, including the QE bit. The 100b code is
> > + *         used if writing one byte to the status register does not modify
> > + *         status register 2.
> > + * - 010b: QE is bit 6 of status register 1. It is set via Write Status with
> > + *         one data byte where bit 6 is one.
> > + *         [...]
> > + * - 011b: QE is bit 7 of status register 2. It is set via Write status
> > + *         register 2 instruction 3Eh with one data byte where bit 7 is one.
> > + *         [...]
> > + *         The status register 2 is read using instruction 3Fh.
> > + * - 100b: QE is bit 1 of status register 2. It is set via Write Status with
> > + *         two data bytes where bit 1 of the second byte is one.
> > + *         [...]
> > + *         In contrast to the 001b code, writing one byte to the status
> > + *         register does not modify status register 2.
> > + * - 101b: QE is bit 1 of status register 2. Status register 1 is read using
> > + *         Read Status instruction 05h. Status register2 is read using
> > + *         instruction 35h. QE is set via Writ Status instruction 01h with
> > + *         two data bytes where bit 1 of the second byte is one.
> > + *         [...]
> > + */
> > +#define BFPT_DWORD15_QER_MASK
> 	GENMASK(22, 20)
> > +#define BFPT_DWORD15_QER_NONE			(0x0UL << 20)
> /* Micron */
> > +#define BFPT_DWORD15_QER_SR2_BIT1_BUGGY		(0x1UL << 20)
> > +#define BFPT_DWORD15_QER_SR1_BIT6		(0x2UL << 20) /*
> Macronix */
> > +#define BFPT_DWORD15_QER_SR2_BIT7		(0x3UL << 20)
> > +#define BFPT_DWORD15_QER_SR2_BIT1_NO_RD		(0x4UL << 20)
> > +#define BFPT_DWORD15_QER_SR2_BIT1		(0x5UL << 20) /*
> Spansion */
> > +
> > +struct sfdp_bfpt {
> > +	u32	dwords[BFPT_DWORD_MAX];
> > +};
> > +
> >  struct dm_spi_flash_ops {
> >  	int (*read)(struct udevice *dev, u32 offset, size_t len, void *buf);
> >  	int (*write)(struct udevice *dev, u32 offset, size_t len,
> >


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