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

From: Jagan Teki
Date: Sat Sep 12 2015 - 12:08:36 EST


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.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/