[v4,2/7] mtd: spi-nor: sfdp: parse xSPI Profile 1.0 table

JESD251, xSPI profile 1.0 table supports octal DTR mode.
Extract information like the fast read opcode, dummy cycles for various
frequencies, the number of dummy cycles needed for a Read Status
Register command, the number of address bytes needed for a Read
Status Register command, read volatile register command and write
volatile register command.

According to BFPT 20th DWORD of octal maximum speed, driver get it's
specific dummy cycles from profile 1.0 table and then could update
it to device by their fixup hooks.

Since driver get octal DTR read opcode and then set read settings,
expose spi_nor_set_read_settings() in core.h.

Signed-off-by: Mason Yang <masonccyang@mxic.com.tw>
---
 drivers/mtd/spi-nor/core.c |   2 +-
 drivers/mtd/spi-nor/core.h |  16 +++++++
 drivers/mtd/spi-nor/sfdp.c | 106 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 123 insertions(+), 1 deletion(-)

On 29/05/20 03:36PM, Mason Yang wrote:
> JESD251, xSPI profile 1.0 table supports octal DTR mode.
> Extract information like the fast read opcode, dummy cycles for various
> frequencies, the number of dummy cycles needed for a Read Status
> Register command, the number of address bytes needed for a Read
> Status Register command, read volatile register command and write
> volatile register command.

Like I said before, please don't re-introduce the functions. My patch 
series already parses the table. Add whatever new feature you want on 
top of it.
 
> According to BFPT 20th DWORD of octal maximum speed, driver get it's
> specific dummy cycles from profile 1.0 table and then could update
> it to device by their fixup hooks.

My patch [0] already find out the dummy cycles from the table as you 
suggested, though it doesn't consult the BFPT. Instead, it uses the 
dummy cycle fields themselves as indication that a speed is supported or 
not.
 
[0] https://lore.kernel.org/linux-mtd/20200525091544.17270-10-p.yadav@ti.com/

+ YC Lin in loop,

--
> 
> Subject
> 
> [PATCH v4 2/7] mtd: spi-nor: sfdp: parse xSPI Profile 1.0 table
> 
> JESD251, xSPI profile 1.0 table supports octal DTR mode.
> Extract information like the fast read opcode, dummy cycles for various
> frequencies, the number of dummy cycles needed for a Read Status
> Register command, the number of address bytes needed for a Read
> Status Register command, read volatile register command and write
> volatile register command.
> 
> According to BFPT 20th DWORD of octal maximum speed, driver get it's
> specific dummy cycles from profile 1.0 table and then could update
> it to device by their fixup hooks.
> 
> Since driver get octal DTR read opcode and then set read settings,
> expose spi_nor_set_read_settings() in core.h.
> 
> Signed-off-by: Mason Yang <masonccyang@mxic.com.tw>
> ---


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Hi, Mason, YC Lin,

On 5/29/20 10:36 AM, Mason Yang wrote:
> JESD251, xSPI profile 1.0 table supports octal DTR mode.
> Extract information like the fast read opcode, dummy cycles for various
> frequencies, the number of dummy cycles needed for a Read Status
> Register command, the number of address bytes needed for a Read
> Status Register command, read volatile register command and write
> volatile register command.
> 
> According to BFPT 20th DWORD of octal maximum speed, driver get it's
> specific dummy cycles from profile 1.0 table and then could update
> it to device by their fixup hooks.
> 
> Since driver get octal DTR read opcode and then set read settings,
> expose spi_nor_set_read_settings() in core.h.
> 
> Signed-off-by: Mason Yang <masonccyang@mxic.com.tw>
> ---
>  drivers/mtd/spi-nor/core.c |   2 +-
>  drivers/mtd/spi-nor/core.h |  16 +++++++
>  drivers/mtd/spi-nor/sfdp.c | 106 +++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 123 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
> index 1ab4386..3799417 100644
> --- a/drivers/mtd/spi-nor/core.c
> +++ b/drivers/mtd/spi-nor/core.c
> @@ -2204,7 +2204,7 @@ static int spi_nor_check(struct spi_nor *nor)
>  	return 0;
>  }
>  
> -static void
> +void
>  spi_nor_set_read_settings(struct spi_nor_read_command *read,
>  			  u8 num_mode_clocks,
>  			  u8 num_wait_states,
> diff --git a/drivers/mtd/spi-nor/core.h b/drivers/mtd/spi-nor/core.h
> index 7a36b22..a33f807 100644
> --- a/drivers/mtd/spi-nor/core.h
> +++ b/drivers/mtd/spi-nor/core.h
> @@ -191,6 +191,12 @@ struct spi_nor_locking_ops {
>   * @size:		the flash memory density in bytes.
>   * @page_size:		the page size of the SPI NOR flash memory.
>   * @octal_max_speed:	maximum operation speed of device in octal mode.
> + * @rdsr_dummy:		dummy cycles needed for Read Status Register command.
> + * @rdsr_addr_nbytes:	dummy address bytes needed for Read Status Register
> + *			command.
> + * @rd_reg_cmd:		read volatile register command for xSPI device.
> + * @wr_reg_cmd:		write volatile register command for xSPI device.

Can all the volatile registers be accessed with these commands?
The profile1.0 table lacks description.

> + * @dummy_cycles:	dummy cycles used for various frequencies
>   * @hwcaps:		describes the read and page program hardware
>   *			capabilities.
>   * @reads:		read capabilities ordered by priority: the higher index
> @@ -214,6 +220,11 @@ struct spi_nor_flash_parameter {
>  	u64				size;
>  	u32				page_size;
>  	u16				octal_max_speed;
> +	u8				rdsr_dummy;
> +	u8				rdsr_addr_nbytes;
> +	u8				rd_reg_cmd;
> +	u8				wr_reg_cmd;
> +	u8				dummy_cycles;
>  
>  	struct spi_nor_hwcaps		hwcaps;
>  	struct spi_nor_read_command	reads[SNOR_CMD_READ_MAX];
> @@ -420,6 +431,11 @@ ssize_t spi_nor_write_data(struct spi_nor *nor, loff_t to, size_t len,
>  
>  int spi_nor_hwcaps_read2cmd(u32 hwcaps);
>  u8 spi_nor_convert_3to4_read(u8 opcode);
> +void spi_nor_set_read_settings(struct spi_nor_read_command *read,
> +			       u8 num_mode_clocks,
> +			       u8 num_wait_states,
> +			       u8 opcode,
> +			       enum spi_nor_protocol proto);
>  void spi_nor_set_pp_settings(struct spi_nor_pp_command *pp, u8 opcode,
>  			     enum spi_nor_protocol proto);
>  
> diff --git a/drivers/mtd/spi-nor/sfdp.c b/drivers/mtd/spi-nor/sfdp.c
> index 4d13f66..27a4de4 100644
> --- a/drivers/mtd/spi-nor/sfdp.c
> +++ b/drivers/mtd/spi-nor/sfdp.c
> @@ -20,6 +20,7 @@
>  #define SFDP_BFPT_ID		0xff00	/* Basic Flash Parameter Table */
>  #define SFDP_SECTOR_MAP_ID	0xff81	/* Sector Map Table */
>  #define SFDP_4BAIT_ID		0xff84  /* 4-byte Address Instruction Table */
> +#define SFDP_PROFILE1_ID	0xff05	/* xSPI Profile 1.0 table. */
>  
>  #define SFDP_SIGNATURE		0x50444653U
>  #define SFDP_JESD216_MAJOR	1
> @@ -27,6 +28,27 @@
>  #define SFDP_JESD216A_MINOR	5
>  #define SFDP_JESD216B_MINOR	6
>  
> +/* xSPI Profile 1.0 table (from JESD216D.01). */
> +#define XSPI_PF1_DWORD1_RD_CMD                  GENMASK(15, 8)
> +#define XSPI_PF1_DWORD1_RDSR_ADDR_BYTES         BIT(29)
> +#define XSPI_PF1_DWORD1_RDSR_DUMMY_CYCLES       BIT(28)
> +#define XSPI_PF1_DWORD2_RD_REG_CMD              GENMASK(31, 24)
> +#define XSPI_PF1_DWORD2_WR_REG_CMD              GENMASK(15, 8)
> +#define XSPI_PF1_DUMMY_CYCLES_DEFAULT		20
> +#define XSPI_DWORD(x)   ((x) - 1)
> +#define XSPI_DWORD_MAX  5
> +
> +struct sfdp_xspi {
> +	u32 dwords[XSPI_DWORD_MAX];
> +};
> +
> +struct xspi_dummy_cycles {
> +	u16 speed_hz;	/* Speed MHz */
> +	u8 dwords;	/* Dwords index */
> +	u32 mask;	/* Mask */
> +	u8 shift;	/* Bit shift */
> +};
> +
>  /* Basic Flash Parameter Table 20th DWORD, Max operation speed of device */
>  struct octal_max_speed {
>  	u8 idx; /* Bits value */
> @@ -1117,6 +1139,86 @@ static int spi_nor_parse_4bait(struct spi_nor *nor,
>  }
>  
>  /**
> + * spi_nor_parse_profile1() - parse the xSPI Profile 1.0 table
> + * @nor:		pointer to a 'struct spi_nor'
> + * @param_header:	xspi profile 1 parameter table header
> + * @params:		pointer to the 'struct spi_nor_flash_parameter' to be.
> + *
> + * Return: 0 on success, -errno otherwise.
> + */
> +static int spi_nor_parse_profile1(struct spi_nor *nor,
> +				  const struct sfdp_parameter_header *header,
> +				  struct spi_nor_flash_parameter *params)
> +{
> +	struct sfdp_xspi pfile1;
> +	u8 opcode;
> +	u32 i, addr;
> +	size_t len;
> +	int ret;
> +	static const struct xspi_dummy_cycles dummy[] = {
> +		/* {MHz, Dwords index, Mask, Bit shift} */
> +		{ 200, 4, GENMASK(11, 7),   7},
> +		{ 166, 5, GENMASK(31, 27), 27},
> +		{ 133, 5, GENMASK(21, 17), 17},
> +		{ 100, 5, GENMASK(11, 7),   7},
> +	};
> +
> +	if (header->major != SFDP_JESD216_MAJOR ||
> +	    header->length < XSPI_DWORD_MAX)
> +		return -EINVAL;
> +
> +	len = min_t(size_t, sizeof(pfile1),
> +		    header->length * sizeof(u32));
> +
> +	memset(&pfile1, 0, sizeof(pfile1));
> +
> +	addr = SFDP_PARAM_HEADER_PTP(header);
> +	ret = spi_nor_read_sfdp(nor, addr, len, &pfile1);
> +	if (ret)
> +		goto out;
> +
> +	/* Fix endianness of the xSPI 1.0 DWORDs. */
> +	le32_to_cpu_array(pfile1.dwords, XSPI_DWORD_MAX);
> +
> +	/* Get 8D-8D-8D fast read opcode and dummy cycles. */
> +	opcode = FIELD_GET(XSPI_PF1_DWORD1_RD_CMD,
> +			   pfile1.dwords[XSPI_DWORD(1)]);
> +
> +	if (pfile1.dwords[XSPI_DWORD(1)] & XSPI_PF1_DWORD1_RDSR_ADDR_BYTES)
> +		params->rdsr_addr_nbytes = 4;
> +	else
> +		params->rdsr_addr_nbytes = 0;
> +
> +	if (pfile1.dwords[XSPI_DWORD(1)] & XSPI_PF1_DWORD1_RDSR_DUMMY_CYCLES)
> +		params->rdsr_dummy = 8;
> +	else
> +		params->rdsr_dummy = 4;
> +
> +	params->rd_reg_cmd = FIELD_GET(XSPI_PF1_DWORD2_RD_REG_CMD,
> +				       pfile1.dwords[XSPI_DWORD(2)]);
> +	params->wr_reg_cmd = FIELD_GET(XSPI_PF1_DWORD2_WR_REG_CMD,
> +				       pfile1.dwords[XSPI_DWORD(2)]);
> +
> +	/* according to BFPT 20th DOWRD to get devices dummy cycles */
> +	for (i = 0; i < ARRAY_SIZE(dummy); i++) {
> +		if (params->octal_max_speed == dummy[i].speed_hz) {

Why do you introduced this restriction? The dummy cycles fields themselves
can be used to determine if a speed is supported or not. A value different
than zero for the dummy cycles fields means that the corresponding frequency
is supported.

Cheers,
ta


> +			params->dummy_cycles = (dummy[i].mask &
> +				pfile1.dwords[XSPI_DWORD(dummy[i].dwords)]) >>
> +				dummy[i].shift;
> +			break;
> +		}
> +	}
> +	if (i == ARRAY_SIZE(dummy))
> +		params->dummy_cycles = XSPI_PF1_DUMMY_CYCLES_DEFAULT;
> +
> +	spi_nor_set_read_settings(&params->reads[SNOR_CMD_READ_8_8_8_DTR],
> +				  0, params->dummy_cycles,
> +				  opcode, SNOR_PROTO_8_8_8_DTR);
> +out:
> +	return ret;
> +}
> +
> +/**
>   * spi_nor_parse_sfdp() - parse the Serial Flash Discoverable Parameters.
>   * @nor:		pointer to a 'struct spi_nor'
>   * @params:		pointer to the 'struct spi_nor_flash_parameter' to be
> @@ -1217,6 +1319,10 @@ int spi_nor_parse_sfdp(struct spi_nor *nor,
>  			err = spi_nor_parse_4bait(nor, param_header, params);
>  			break;
>  
> +		case SFDP_PROFILE1_ID:
> +			err = spi_nor_parse_profile1(nor, param_header, params);
> +			break;
> +
>  		default:
>  			break;
>  		}
>