Re: [PATCH v7 07/14] spi: spi-mem: Add an ecc_en parameter to the spi_mem_op structure

Pratyush Yadav
2021-12-20T19:10:29Z

On 17/12/21 05:16PM, Miquel Raynal wrote:
> Soon the SPI-NAND core will need a way to request a SPI controller to
> enable ECC support for a given operation. This is because of the
> pipelined integration of certain ECC engines, which are directly managed
> by the SPI controller itself.
>
> Introduce a spi_mem_op additional field for this purpose: ecc_en.
>
> So far this field is left unset and checked to be false by all
> the SPI controller drivers in their ->supports_op() hook, as they all
> call spi_mem_default_supports_op().
>
> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
> ---
> drivers/spi/spi-mem.c | 5 +++++
> include/linux/spi/spi-mem.h | 5 +++++
> 2 files changed, 10 insertions(+)
>
> diff --git a/drivers/spi/spi-mem.c b/drivers/spi/spi-mem.c
> index cfe1c99db5f3..94758e7e747d 100644
> --- a/drivers/spi/spi-mem.c
> +++ b/drivers/spi/spi-mem.c
> @@ -178,6 +178,11 @@ bool spi_mem_default_supports_op(struct spi_mem *mem,
> return false;
> }
>
> + if (op->ecc_en) {
> + if (!spi_mem_controller_is_capable(ctlr, ecc))
> + return false;
> + }
> +
> return spi_mem_check_buswidth(mem, op);
> }
> EXPORT_SYMBOL_GPL(spi_mem_default_supports_op);
> diff --git a/include/linux/spi/spi-mem.h b/include/linux/spi/spi-mem.h
> index d7787c8f3746..e9238a858109 100644
> --- a/include/linux/spi/spi-mem.h
> +++ b/include/linux/spi/spi-mem.h
> @@ -94,6 +94,7 @@ enum spi_mem_data_dir {
> * operation does not involve transferring data
> * @data.buf.in: input buffer (must be DMA-able)
> * @data.buf.out: output buffer (must be DMA-able)
> + * @ecc_en: error correction is required
> */
> struct spi_mem_op {
> struct {
> @@ -126,6 +127,8 @@ struct spi_mem_op {
> const void *out;
> } buf;
> } data;
> +
> + bool ecc_en;

ECC should only concern the data phase right? Would it make more sense
to move this field under data?

Anyway, I don't know much about NAND or ECC so either way,

Acked-by: Pratyush Yadav <p.yadav@ti.com>

> };
>
> #define SPI_MEM_OP(__cmd, __addr, __dummy, __data) \
> @@ -223,9 +226,11 @@ static inline void *spi_mem_get_drvdata(struct spi_mem *mem)
> /**
> * struct spi_controller_mem_caps - SPI memory controller capabilities
> * @dtr: Supports DTR operations
> + * @ecc: Supports operations with error correction
> */
> struct spi_controller_mem_caps {
> bool dtr;
> + bool ecc;
> };
>
> #define spi_mem_controller_is_capable(ctlr, cap) \
> --
> 2.27.0
>

--
Regards,
Pratyush Yadav
Texas Instruments Inc.