Re: [PATCH v2 3/3] mtd: spi-nor: Add clear flag status register support

[Jagan Teki]

On 1 September 2015 at 21:40, Jagan Teki <jteki@xxxxxxxxxxxx> wrote:
> On 26 August 2015 at 16:18, Jagan Teki <jteki@xxxxxxxxxxxx> wrote:
>> The clear flag status register operation is required by Micron
>> SPI-NOR chips, which support FSR. And if error bits of FSR
>> have been set like protection, voltage, erase, and program,
>> it must be cleared by executing clear FSR operation.
>>
>> Signed-off-by: Jagan Teki <jteki@xxxxxxxxxxxx>
>> Cc: Hou Zhiqiang <B48286@xxxxxxxxxxxxx>
>> Cc: Mingkai.Hu <Mingkai.Hu@xxxxxxxxxxxxx>
>> Cc: David Woodhouse <dwmw2@xxxxxxxxxxxxx>
>> Cc: Brian Norris <computersforpeace@xxxxxxxxx>
>
> Any response, please comment
>
>> ---
>> Changes for v2:
>>         - Write cfsr instead of reading it.
>>         - Return -EINVAL instead of -1
>>
>>  drivers/mtd/spi-nor/spi-nor.c | 23 +++++++++++++++++++----
>>  include/linux/mtd/spi-nor.h   |  9 +++++++++
>>  2 files changed, 28 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
>> index f954d03..0a77061 100644
>> --- a/drivers/mtd/spi-nor/spi-nor.c
>> +++ b/drivers/mtd/spi-nor/spi-nor.c
>> @@ -163,6 +163,18 @@ static inline int write_disable(struct spi_nor *nor)
>>         return nor->write_reg(nor, SPINOR_OP_WRDI, NULL, 0);
>>  }
>>
>> +/*
>> + * The clear flag status register operation is required by Micron
>> + * SPI-NOR chips, which support FSR. And if error bits of FSR
>> + * have been set like protection, voltage, erase, and program,
>> + * it must be cleared by executing clear FSR operation.
>> + * Returns negative if error occurred.
>> + */
>> +static inline int write_cfsr(struct spi_nor *nor)
>> +{
>> +       return nor->write_reg(nor, SPINOR_OP_WRCFSR, NULL, 0);
>> +}
>> +
>>  static inline struct spi_nor *mtd_to_spi_nor(struct mtd_info *mtd)
>>  {
>>         return mtd->priv;
>> @@ -209,10 +221,13 @@ static inline int spi_nor_sr_ready(struct spi_nor *nor)
>>  static inline int spi_nor_fsr_ready(struct spi_nor *nor)
>>  {
>>         int fsr = read_fsr(nor);
>> -       if (fsr < 0)
>> -               return fsr;
>> -       else
>> -               return fsr & FSR_READY;
>> +       if (fsr & FSR_ERR_MASK) {
>> +               pr_err("flag status(0x%x) error occured\n", fsr);
>> +               write_cfsr(nor);
>> +               return -EINVAL;
>> +       }
>> +
>> +       return fsr & FSR_READY;
>>  }
>>
>>  static int spi_nor_ready(struct spi_nor *nor)
>> diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
>> index c5a58c4..0288081 100644
>> --- a/include/linux/mtd/spi-nor.h
>> +++ b/include/linux/mtd/spi-nor.h
>> @@ -35,6 +35,7 @@
>>  #define SPINOR_OP_RDID         0x9f    /* Read JEDEC ID */
>>  #define SPINOR_OP_RDCR         0x35    /* Read configuration register */
>>  #define SPINOR_OP_RDFSR                0x70    /* Read flag status register */
>> +#define SPINOR_OP_WRCFSR       0x50    /* Write clear flag status register */
>>
>>  /* 4-byte address opcodes - used on Spansion and some Macronix flashes. */
>>  #define SPINOR_OP_READ4                0x13    /* Read data bytes (low frequency) */
>> @@ -74,6 +75,14 @@
>>  /* Enhanced Volatile Configuration Register bits */
>>  #define EVCR_QUAD_EN_MICRON    0x80    /* Micron Quad I/O */
>>
>> +/* Flag Status Register Error bits */
>> +#define FSR_ERR_PROT           0x2     /* Protection */
>> +#define FSR_ERR_VOLT           0x8     /* Voltage on Vpp */
>> +#define FSR_ERR_PROG           0x10    /* Program operation */
>> +#define FSR_ERR_ERASE          0x20    /* Erase operation */
>> +#define FSR_ERR_MASK           (FSR_ERR_PROT | FSR_ERR_VOLT | \
>> +                               FSR_ERR_PROG | FSR_ERR_ERASE)
>> +
>>  /* Flag Status Register bits */
>>  #define FSR_READY              0x80
>>
>> --
>> 1.9.1

Ping!

thanks!
-- 
Jagan | openedev.
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