diff mbox series

[v2,02/14] mtd: spinand: Add enum spinand_proto to indicate current SPI IO mode

Message ID 20211011204619.81893-3-a-nandan@ti.com
State Changes Requested
Headers show
Series mtd: spinand: Add Octal DTR SPI (8D-8D-8D) mode support | expand

Commit Message

Apurva Nandan Oct. 11, 2021, 8:46 p.m. UTC 
Unlike Dual and Quad SPI modes flashes, Octal DTR SPI NAND flashes
require all instructions to be made in 8D-8D-8D protocol when the
flash is in Octal DTR mode. Hence, storing the current SPI IO mode
becomes necessary for correctly generating non-array access operations.

Store the current SPI IO mode in the spinand struct using a reg_proto
enum. This would act as a flag, denoting that the core should use
the given SPI protocol for non-page access operations.

Also provide basic macros for extracting buswidth and dtr mode
information from the spinand_proto enum.

Signed-off-by: Apurva Nandan <a-nandan@ti.com>
---
 drivers/mtd/nand/spi/core.c |  2 ++
 include/linux/mtd/spinand.h | 30 ++++++++++++++++++++++++++++++
 2 files changed, 32 insertions(+)

Comments

Boris Brezillon Oct. 12, 2021, 6:39 a.m. UTC | #1 
On Tue, 12 Oct 2021 02:16:07 +0530
Apurva Nandan <a-nandan@ti.com> wrote:

> Unlike Dual and Quad SPI modes flashes, Octal DTR SPI NAND flashes
> require all instructions to be made in 8D-8D-8D protocol when the
> flash is in Octal DTR mode. Hence, storing the current SPI IO mode
> becomes necessary for correctly generating non-array access operations.
> 
> Store the current SPI IO mode in the spinand struct using a reg_proto
> enum. This would act as a flag, denoting that the core should use
> the given SPI protocol for non-page access operations.
> 
> Also provide basic macros for extracting buswidth and dtr mode
> information from the spinand_proto enum.
> 
> Signed-off-by: Apurva Nandan <a-nandan@ti.com>
> ---
>  drivers/mtd/nand/spi/core.c |  2 ++
>  include/linux/mtd/spinand.h | 30 ++++++++++++++++++++++++++++++
>  2 files changed, 32 insertions(+)
> 
> diff --git a/drivers/mtd/nand/spi/core.c b/drivers/mtd/nand/spi/core.c
> index 2c8685f1f2fa..d82a3e6d9bb5 100644
> --- a/drivers/mtd/nand/spi/core.c
> +++ b/drivers/mtd/nand/spi/core.c
> @@ -1155,6 +1155,7 @@ static void spinand_mtd_resume(struct mtd_info *mtd)
>  	struct spinand_device *spinand = mtd_to_spinand(mtd);
>  	int ret;
>  
> +	spinand->reg_proto = SPINAND_SINGLE_STR;
>  	ret = spinand_reset_op(spinand);
>  	if (ret)
>  		return;
> @@ -1181,6 +1182,7 @@ static int spinand_init(struct spinand_device *spinand)
>  	if (!spinand->scratchbuf)
>  		return -ENOMEM;
>  
> +	spinand->reg_proto = SPINAND_SINGLE_STR;
>  	ret = spinand_detect(spinand);
>  	if (ret)
>  		goto err_free_bufs;
> diff --git a/include/linux/mtd/spinand.h b/include/linux/mtd/spinand.h
> index 6988956b8492..f6093cd98d7b 100644
> --- a/include/linux/mtd/spinand.h
> +++ b/include/linux/mtd/spinand.h
> @@ -140,6 +140,31 @@
>  		   SPI_MEM_OP_NO_DUMMY,					\
>  		   SPI_MEM_OP_DATA_OUT(len, buf, 4))
>  
> +#define SPINAND_PROTO_BUSWIDTH_MASK	GENMASK(6, 0)
> +#define SPINAND_PROTO_DTR_BIT		BIT(7)
> +
> +#define SPINAND_PROTO_STR(__buswidth)	\
> +	((u8)(((__buswidth) - 1) & SPINAND_PROTO_BUSWIDTH_MASK))
> +#define SPINAND_PROTO_DTR(__buswidth)	\
> +	(SPINAND_PROTO_DTR_BIT | SPINAND_PROTO_STR(__buswidth))
> +
> +#define SPINAND_PROTO_BUSWIDTH(__proto)	\
> +	((u8)(((__proto) & SPINAND_PROTO_BUSWIDTH_MASK) + 1))
> +#define SPINAND_PROTO_IS_DTR(__proto)	(!!((__proto) & SPINAND_PROTO_DTR_BIT))
> +
> +/**
> + * enum spinand_proto - List allowable SPI protocol variants for read reg,
> + *			write reg, blk erase, write enable/disable, page read
> + *			and program exec operations.
> + */
> +enum spinand_proto {

s/spinand_proto/spinand_protocol/

> +	SPINAND_SINGLE_STR = SPINAND_PROTO_STR(1),
> +	SPINAND_DUAL_STR = SPINAND_PROTO_STR(2),
> +	SPINAND_QUAD_STR = SPINAND_PROTO_STR(4),
> +	SPINAND_OCTAL_STR = SPINAND_PROTO_STR(8),
> +	SPINAND_OCTAL_DTR = SPINAND_PROTO_DTR(8),

Why not have a contiguous enum listing all the modes? Are you extracting
the buswidth from these values?

> +};
> +
>  /**
>   * Standard SPI NAND flash commands
>   */
> @@ -407,6 +432,9 @@ struct spinand_dirmap {
>   *		   this die. Only required if your chip exposes several dies
>   * @cur_target: currently selected target/die
>   * @eccinfo: on-die ECC information
> + * @reg_proto: select a variant of SPI IO protocol (single, quad, octal or
> + *	       octal DTR) for read_reg/write_reg/erase operations. Update on
> + *	       successful transition into a different SPI IO protocol.
>   * @cfg_cache: config register cache. One entry per die
>   * @databuf: bounce buffer for data
>   * @oobbuf: bounce buffer for OOB data
> @@ -438,6 +466,8 @@ struct spinand_device {
>  
>  	struct spinand_ecc_info eccinfo;
>  
> +	enum spinand_proto reg_proto;
> +

I guess this mode will apply to all sort of commands, not just reg
accesses, so why not name it protocol or mode?

>  	u8 *cfg_cache;
>  	u8 *databuf;
>  	u8 *oobbuf;
diff mbox series

Patch

diff --git a/drivers/mtd/nand/spi/core.c b/drivers/mtd/nand/spi/core.c
index 2c8685f1f2fa..d82a3e6d9bb5 100644
--- a/drivers/mtd/nand/spi/core.c
+++ b/drivers/mtd/nand/spi/core.c
@@ -1155,6 +1155,7 @@  static void spinand_mtd_resume(struct mtd_info *mtd)
 	struct spinand_device *spinand = mtd_to_spinand(mtd);
 	int ret;
 
+	spinand->reg_proto = SPINAND_SINGLE_STR;
 	ret = spinand_reset_op(spinand);
 	if (ret)
 		return;
@@ -1181,6 +1182,7 @@  static int spinand_init(struct spinand_device *spinand)
 	if (!spinand->scratchbuf)
 		return -ENOMEM;
 
+	spinand->reg_proto = SPINAND_SINGLE_STR;
 	ret = spinand_detect(spinand);
 	if (ret)
 		goto err_free_bufs;
diff --git a/include/linux/mtd/spinand.h b/include/linux/mtd/spinand.h
index 6988956b8492..f6093cd98d7b 100644
--- a/include/linux/mtd/spinand.h
+++ b/include/linux/mtd/spinand.h
@@ -140,6 +140,31 @@ 
 		   SPI_MEM_OP_NO_DUMMY,					\
 		   SPI_MEM_OP_DATA_OUT(len, buf, 4))
 
+#define SPINAND_PROTO_BUSWIDTH_MASK	GENMASK(6, 0)
+#define SPINAND_PROTO_DTR_BIT		BIT(7)
+
+#define SPINAND_PROTO_STR(__buswidth)	\
+	((u8)(((__buswidth) - 1) & SPINAND_PROTO_BUSWIDTH_MASK))
+#define SPINAND_PROTO_DTR(__buswidth)	\
+	(SPINAND_PROTO_DTR_BIT | SPINAND_PROTO_STR(__buswidth))
+
+#define SPINAND_PROTO_BUSWIDTH(__proto)	\
+	((u8)(((__proto) & SPINAND_PROTO_BUSWIDTH_MASK) + 1))
+#define SPINAND_PROTO_IS_DTR(__proto)	(!!((__proto) & SPINAND_PROTO_DTR_BIT))
+
+/**
+ * enum spinand_proto - List allowable SPI protocol variants for read reg,
+ *			write reg, blk erase, write enable/disable, page read
+ *			and program exec operations.
+ */
+enum spinand_proto {
+	SPINAND_SINGLE_STR = SPINAND_PROTO_STR(1),
+	SPINAND_DUAL_STR = SPINAND_PROTO_STR(2),
+	SPINAND_QUAD_STR = SPINAND_PROTO_STR(4),
+	SPINAND_OCTAL_STR = SPINAND_PROTO_STR(8),
+	SPINAND_OCTAL_DTR = SPINAND_PROTO_DTR(8),
+};
+
 /**
  * Standard SPI NAND flash commands
  */
@@ -407,6 +432,9 @@  struct spinand_dirmap {
  *		   this die. Only required if your chip exposes several dies
  * @cur_target: currently selected target/die
  * @eccinfo: on-die ECC information
+ * @reg_proto: select a variant of SPI IO protocol (single, quad, octal or
+ *	       octal DTR) for read_reg/write_reg/erase operations. Update on
+ *	       successful transition into a different SPI IO protocol.
  * @cfg_cache: config register cache. One entry per die
  * @databuf: bounce buffer for data
  * @oobbuf: bounce buffer for OOB data
@@ -438,6 +466,8 @@  struct spinand_device {
 
 	struct spinand_ecc_info eccinfo;
 
+	enum spinand_proto reg_proto;
+
 	u8 *cfg_cache;
 	u8 *databuf;
 	u8 *oobbuf;