[PATCH 2/2] mtd: spi-nor: spansion: uses CLSR command in S25FL{064|128|256}L chips

Yaliang.Wang Yaliang.Wang at windriver.com
Thu Apr 1 19:44:27 BST 2021


Hi, Pratyush

Appreciate for your carefully review.

On 3/2/21 7:15 PM, Pratyush Yadav wrote:
> [Please note: This e-mail is from an EXTERNAL e-mail address]
>
> On 01/03/21 10:28PM,yaliang.wang at windriver.com  wrote:
>> From: Yaliang Wang<Yaliang.Wang at windriver.com>
>>
>> S25FL{064|128|256}L chips can't recover from errors when program error
>> or erase error occurs, P_ERR or E_ERR bit will be set to one, WIP bit
>> will remain set to one, A Clear Status Register command must be sent to
>> return the device to STANDBY state.
>>
>> First record of the can't recover error is in commit <c4b3eacc1dfe>
>> ("mtd: spi-nor: Recover from Spansion/Cypress errors"). The error has
>> been fixed by the commit, however, S25FL-L chips shifted P_ERR and E_ERR
>> bits from SR1 to SR2, which makes the previous fix no longer work.
>>
>> Signed-off-by: Yaliang Wang<Yaliang.Wang at windriver.com>
>> ---
>>   drivers/mtd/spi-nor/spansion.c | 96 ++++++++++++++++++++++++++++++++--
>>   1 file changed, 93 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/mtd/spi-nor/spansion.c b/drivers/mtd/spi-nor/spansion.c
>> index 67619b64c148..4ed98cb969a5 100644
>> --- a/drivers/mtd/spi-nor/spansion.c
>> +++ b/drivers/mtd/spi-nor/spansion.c
>> @@ -19,7 +19,10 @@
>>   #define SPINOR_REG_CYPRESS_CFR5V_OCT_DTR_DS  0
>>   #define SPINOR_OP_CYPRESS_RD_FAST            0xee
>>   #define SPINOR_OP_SPANSION_CLSR                      0x30
>> +#define SPINOR_OP_SPANSION_SR2                       0x07
>>
>> +#define S25FL_L_SR2_P_ERR BIT(5)
>> +#define S25FL_L_SR2_E_ERR BIT(6)
> Nitpick: Align the BIT() part with the lines above so it all looks nice.
>
>>   /**
>>    * spi_nor_cypress_octal_dtr_enable() - Enable octal DTR on Cypress flashes.
>>    * @nor:             pointer to a 'struct spi_nor'
>> @@ -203,6 +206,38 @@ static void spansion_clear_sr(struct spi_nor *nor)
>>                dev_dbg(nor->dev, "error %d clearing SR\n", ret);
>>   }
>>
>> +/**
>> + * spansion_read_sr2() - Read the Status Register 2 using the
>> + * SPINOR_OP_SPANSION_SR2 (07h) command.
>> + * @nor:     pointer to 'struct spi_nor'.
>> + * @sr2:     pointer to DMA-able buffer where the value of the
>> + *           Status Register 2 will be written.
>> + *
>> + * Return: 0 on success, -errno otherwise.
>> + */
>> +static int spansion_read_sr2(struct spi_nor *nor, u8 *sr2)
>> +{
>> +     int ret;
>> +
>> +     if (nor->spimem) {
>> +             struct spi_mem_op op =
>> +                     SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_SPANSION_SR2, 1),
>> +                                SPI_MEM_OP_NO_ADDR,
>> +                                SPI_MEM_OP_NO_DUMMY,
>> +                                SPI_MEM_OP_DATA_IN(1, sr2, 1));
> The datasheet says that this command is not available in QPI mode. The
> flashes set SPI_NOR_QUAD_READ. So they will be put into QPI mode and
> will be unable to execute this, right? Why does this work then?
Didn't aware of that before, the correct opcode should be RDAR(0x65), 
will correct it in later patches.
>> +
>> +             ret = spi_mem_exec_op(nor->spimem, &op);
>> +     } else {
>> +             ret = nor->controller_ops->read_reg(nor, SPINOR_OP_SPANSION_SR2,
>> +                                                 sr2, 1);
>> +     }
>> +
>> +     if (ret)
>> +             dev_dbg(nor->dev, "error %d reading SR2\n", ret);
>> +
>> +     return ret;
>> +}
>> +
>>   /**
>>    * spansion_sr_ready() - Spansion specific method for querying the flash to
>>    * see if it is ready for new commands.
>> @@ -244,6 +279,55 @@ static int spansion_sr_ready(struct spi_nor *nor)
>>        return !(sr[0] & SR_WIP);
>>   }
>>
>> +/**
>> + * s25fl_l_sr_ready() - s25fl_l family specific method for querying the flash
>> + * to see if it is ready for new commands.
>> + * @nor:     pointer to 'struct spi_nor'.
>> + *
>> + * Return: 1 if ready, 0 if not ready, -errno on errors.
>> + */
>> +static int s25fl_l_sr_ready(struct spi_nor *nor)
>> +{
>> +     u8 *sr = nor->bouncebuf;
>> +     int ret;
>> +
>> +     ret = spi_nor_read_sr(nor, sr);
>> +     if (ret)
>> +             return ret;
>> +
>> +     ret = spansion_read_sr2(nor, &sr[1]);
>> +     if (ret)
>> +             return ret;
> Since SR2 is only used when SNOR_F_USE_CLSR is set, only run
> spansion_read_sr2() when the flag is set to avoid running it for flashes
> that don't need it.
>
> On that note, since this function is called s25fl_l_sr_ready(), you
> already know this flash can use CLSR. So why even check for the flag at
> all?
You are right, the check can be eliminated.
>> +
>> +     if (nor->flags & SNOR_F_USE_CLSR &&
>> +                     sr[1] & (S25FL_L_SR2_E_ERR | S25FL_L_SR2_P_ERR)) {
> Align with open parenthesis.
>
>> +             if (sr[1] & S25FL_L_SR2_E_ERR)
>> +                     dev_err(nor->dev, "Erase Error occurred\n");
>> +             else
>> +                     dev_err(nor->dev, "Programming Error occurred\n");
>> +
>> +             spansion_clear_sr(nor);
>> +
>> +             /*
>> +              * WEL bit remains set to one when an erase or page program
>> +              * error occurs. Issue a Write Disable command to protect
>> +              * against inadvertent writes that can possibly corrupt the
>> +              * contents of the memory.
>> +              */
>> +             ret = spi_nor_write_disable(nor);
>> +             if (ret)
>> +                     return ret;
>> +
>> +             return -EIO;
>> +     }
>> +
>> +     return !(sr[0] & SR_WIP);
>> +}
>> +
>> +static struct spi_nor_fixups s25fl_l_fixups = {
>> +     .sr_ready = s25fl_l_sr_ready,
>> +};
>> +
>>   static int
>>   s25fs_s_post_bfpt_fixups(struct spi_nor *nor,
>>                         const struct sfdp_parameter_header *bfpt_header,
>> @@ -331,13 +415,19 @@ static const struct flash_info spansion_parts[] = {
>>                             SECT_4K | SPI_NOR_DUAL_READ) },
>>        { "s25fl064l",  INFO(0x016017,      0,  64 * 1024, 128,
>>                             SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ |
>> -                          SPI_NOR_4B_OPCODES) },
>> +                          SPI_NOR_4B_OPCODES | USE_CLSR)
>> +             .fixups = &s25fl_l_fixups,
>> +     },
>>        { "s25fl128l",  INFO(0x016018,      0,  64 * 1024, 256,
>>                             SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ |
>> -                          SPI_NOR_4B_OPCODES) },
>> +                          SPI_NOR_4B_OPCODES | USE_CLSR)
>> +             .fixups = &s25fl_l_fixups,
>> +     },
>>        { "s25fl256l",  INFO(0x016019,      0,  64 * 1024, 512,
>>                             SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ |
>> -                          SPI_NOR_4B_OPCODES) },
>> +                          SPI_NOR_4B_OPCODES | USE_CLSR)
>> +             .fixups = &s25fl_l_fixups,
>> +     },
>>        { "cy15x104q",  INFO6(0x042cc2, 0x7f7f7f, 512 * 1024, 1,
>>                              SPI_NOR_NO_ERASE) },
>>        { "s28hs512t",   INFO(0x345b1a,      0, 256 * 1024, 256,
> --
> Regards,
> Pratyush Yadav
> Texas Instruments Inc.
Best Regards,
Yaliang



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