[v10,12/17] mtd: spi-nor: sfdp: detect Soft Reset sequence support from BFPT
diff mbox series

Message ID 20200623183030.26591-13-p.yadav@ti.com
State New
Headers show
Series
  • mtd: spi-nor: add xSPI Octal DTR support
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Commit Message

Pratyush Yadav June 23, 2020, 6:30 p.m. UTC
A Soft Reset sequence will return the flash to Power-on-Reset (POR)
state. It consists of two commands: Soft Reset Enable and Soft Reset.
Find out if the sequence is supported from BFPT DWORD 16.

Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
---
 drivers/mtd/spi-nor/core.h | 1 +
 drivers/mtd/spi-nor/sfdp.c | 4 ++++
 drivers/mtd/spi-nor/sfdp.h | 2 ++
 3 files changed, 7 insertions(+)

Comments

Tudor Ambarus July 8, 2020, 4:08 p.m. UTC | #1
On 6/23/20 9:30 PM, Pratyush Yadav wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
> 
> A Soft Reset sequence will return the flash to Power-on-Reset (POR)
> state. It consists of two commands: Soft Reset Enable and Soft Reset.
> Find out if the sequence is supported from BFPT DWORD 16.
> 
> Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
> ---
>  drivers/mtd/spi-nor/core.h | 1 +
>  drivers/mtd/spi-nor/sfdp.c | 4 ++++
>  drivers/mtd/spi-nor/sfdp.h | 2 ++
>  3 files changed, 7 insertions(+)
> 
> diff --git a/drivers/mtd/spi-nor/core.h b/drivers/mtd/spi-nor/core.h
> index 6338d32a0d77..79ce952c0539 100644
> --- a/drivers/mtd/spi-nor/core.h
> +++ b/drivers/mtd/spi-nor/core.h
> @@ -26,6 +26,7 @@ enum spi_nor_option_flags {
>         SNOR_F_HAS_SR_TB_BIT6   = BIT(11),
>         SNOR_F_HAS_4BIT_BP      = BIT(12),
>         SNOR_F_HAS_SR_BP3_BIT6  = BIT(13),
> +       SNOR_F_SOFT_RESET       = BIT(14),
>  };
> 
>  struct spi_nor_read_command {
> diff --git a/drivers/mtd/spi-nor/sfdp.c b/drivers/mtd/spi-nor/sfdp.c
> index 7983ff431346..8e0741d8bfd3 100644
> --- a/drivers/mtd/spi-nor/sfdp.c
> +++ b/drivers/mtd/spi-nor/sfdp.c
> @@ -616,6 +616,10 @@ static int spi_nor_parse_bfpt(struct spi_nor *nor,
>                 break;
>         }
> 
> +       /* Soft Reset support. */
> +       if (bfpt.dwords[BFPT_DWORD(16)] & BFPT_DWORD16_SOFT_RST)

this can be improved. There are multiple reset methods described and you're
addressing just one of them.

> +               nor->flags |= SNOR_F_SOFT_RESET;
> +
>         /* Stop here if not JESD216 rev C or later. */
>         if (bfpt_header->length == BFPT_DWORD_MAX_JESD216B)
>                 return spi_nor_post_bfpt_fixups(nor, bfpt_header, &bfpt,
> diff --git a/drivers/mtd/spi-nor/sfdp.h b/drivers/mtd/spi-nor/sfdp.h
> index 6d7243067252..8ae55e98084e 100644
> --- a/drivers/mtd/spi-nor/sfdp.h
> +++ b/drivers/mtd/spi-nor/sfdp.h
> @@ -90,6 +90,8 @@ struct sfdp_bfpt {
>  #define BFPT_DWORD15_QER_SR2_BIT1_NO_RD                (0x4UL << 20)
>  #define BFPT_DWORD15_QER_SR2_BIT1              (0x5UL << 20) /* Spansion */
> 
> +#define BFPT_DWORD16_SOFT_RST                  BIT(12)
> +
>  #define BFPT_DWORD18_CMD_EXT_MASK              GENMASK(30, 29)
>  #define BFPT_DWORD18_CMD_EXT_REP               (0x0UL << 29) /* Repeat */
>  #define BFPT_DWORD18_CMD_EXT_INV               (0x1UL << 29) /* Invert */
> --
> 2.27.0
>
Pratyush Yadav July 20, 2020, 4:21 p.m. UTC | #2
Hi Tudor,

On 08/07/20 04:08PM, Tudor.Ambarus@microchip.com wrote:
> On 6/23/20 9:30 PM, Pratyush Yadav wrote:
> > EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
> > 
> > A Soft Reset sequence will return the flash to Power-on-Reset (POR)
> > state. It consists of two commands: Soft Reset Enable and Soft Reset.
> > Find out if the sequence is supported from BFPT DWORD 16.
> > 
> > Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
> > ---
> >  drivers/mtd/spi-nor/core.h | 1 +
> >  drivers/mtd/spi-nor/sfdp.c | 4 ++++
> >  drivers/mtd/spi-nor/sfdp.h | 2 ++
> >  3 files changed, 7 insertions(+)
> > 
> > diff --git a/drivers/mtd/spi-nor/core.h b/drivers/mtd/spi-nor/core.h
> > index 6338d32a0d77..79ce952c0539 100644
> > --- a/drivers/mtd/spi-nor/core.h
> > +++ b/drivers/mtd/spi-nor/core.h
> > @@ -26,6 +26,7 @@ enum spi_nor_option_flags {
> >         SNOR_F_HAS_SR_TB_BIT6   = BIT(11),
> >         SNOR_F_HAS_4BIT_BP      = BIT(12),
> >         SNOR_F_HAS_SR_BP3_BIT6  = BIT(13),
> > +       SNOR_F_SOFT_RESET       = BIT(14),
> >  };
> > 
> >  struct spi_nor_read_command {
> > diff --git a/drivers/mtd/spi-nor/sfdp.c b/drivers/mtd/spi-nor/sfdp.c
> > index 7983ff431346..8e0741d8bfd3 100644
> > --- a/drivers/mtd/spi-nor/sfdp.c
> > +++ b/drivers/mtd/spi-nor/sfdp.c
> > @@ -616,6 +616,10 @@ static int spi_nor_parse_bfpt(struct spi_nor *nor,
> >                 break;
> >         }
> > 
> > +       /* Soft Reset support. */
> > +       if (bfpt.dwords[BFPT_DWORD(16)] & BFPT_DWORD16_SOFT_RST)
> 
> this can be improved. There are multiple reset methods described and you're
> addressing just one of them.

Yes, it can be. But xSPI only cares about the 0x66 and 0x99 reset 
sequence and that is what I implemented. Others can be added if they are 
needed in the future. In addition, I don't have hardware that supports 
these resets so I can't test them. IMO if someone needs other reset 
modes, they should send a separate patch for it.

If you are worried about future work needed to support multiple soft 
reset modes, I can introduce a nor->soft_reset() hook that can be 
populated when parsing BFPT. But I think that is a bit premature. The 
work needed to do that is not a lot so I think we should hold off until 
the need really comes up.
 
> > +               nor->flags |= SNOR_F_SOFT_RESET;
> > +
> >         /* Stop here if not JESD216 rev C or later. */
> >         if (bfpt_header->length == BFPT_DWORD_MAX_JESD216B)
> >                 return spi_nor_post_bfpt_fixups(nor, bfpt_header, &bfpt,
> > diff --git a/drivers/mtd/spi-nor/sfdp.h b/drivers/mtd/spi-nor/sfdp.h
> > index 6d7243067252..8ae55e98084e 100644
> > --- a/drivers/mtd/spi-nor/sfdp.h
> > +++ b/drivers/mtd/spi-nor/sfdp.h
> > @@ -90,6 +90,8 @@ struct sfdp_bfpt {
> >  #define BFPT_DWORD15_QER_SR2_BIT1_NO_RD                (0x4UL << 20)
> >  #define BFPT_DWORD15_QER_SR2_BIT1              (0x5UL << 20) /* Spansion */
> > 
> > +#define BFPT_DWORD16_SOFT_RST                  BIT(12)
> > +
> >  #define BFPT_DWORD18_CMD_EXT_MASK              GENMASK(30, 29)
> >  #define BFPT_DWORD18_CMD_EXT_REP               (0x0UL << 29) /* Repeat */
> >  #define BFPT_DWORD18_CMD_EXT_INV               (0x1UL << 29) /* Invert */

Patch
diff mbox series

diff --git a/drivers/mtd/spi-nor/core.h b/drivers/mtd/spi-nor/core.h
index 6338d32a0d77..79ce952c0539 100644
--- a/drivers/mtd/spi-nor/core.h
+++ b/drivers/mtd/spi-nor/core.h
@@ -26,6 +26,7 @@  enum spi_nor_option_flags {
 	SNOR_F_HAS_SR_TB_BIT6	= BIT(11),
 	SNOR_F_HAS_4BIT_BP      = BIT(12),
 	SNOR_F_HAS_SR_BP3_BIT6  = BIT(13),
+	SNOR_F_SOFT_RESET	= BIT(14),
 };
 
 struct spi_nor_read_command {
diff --git a/drivers/mtd/spi-nor/sfdp.c b/drivers/mtd/spi-nor/sfdp.c
index 7983ff431346..8e0741d8bfd3 100644
--- a/drivers/mtd/spi-nor/sfdp.c
+++ b/drivers/mtd/spi-nor/sfdp.c
@@ -616,6 +616,10 @@  static int spi_nor_parse_bfpt(struct spi_nor *nor,
 		break;
 	}
 
+	/* Soft Reset support. */
+	if (bfpt.dwords[BFPT_DWORD(16)] & BFPT_DWORD16_SOFT_RST)
+		nor->flags |= SNOR_F_SOFT_RESET;
+
 	/* Stop here if not JESD216 rev C or later. */
 	if (bfpt_header->length == BFPT_DWORD_MAX_JESD216B)
 		return spi_nor_post_bfpt_fixups(nor, bfpt_header, &bfpt,
diff --git a/drivers/mtd/spi-nor/sfdp.h b/drivers/mtd/spi-nor/sfdp.h
index 6d7243067252..8ae55e98084e 100644
--- a/drivers/mtd/spi-nor/sfdp.h
+++ b/drivers/mtd/spi-nor/sfdp.h
@@ -90,6 +90,8 @@  struct sfdp_bfpt {
 #define BFPT_DWORD15_QER_SR2_BIT1_NO_RD		(0x4UL << 20)
 #define BFPT_DWORD15_QER_SR2_BIT1		(0x5UL << 20) /* Spansion */
 
+#define BFPT_DWORD16_SOFT_RST			BIT(12)
+
 #define BFPT_DWORD18_CMD_EXT_MASK		GENMASK(30, 29)
 #define BFPT_DWORD18_CMD_EXT_REP		(0x0UL << 29) /* Repeat */
 #define BFPT_DWORD18_CMD_EXT_INV		(0x1UL << 29) /* Invert */