Re: [PATCH v7 02/14] spi: spi-mem: Introduce a capability structure

Pratyush Yadav
2021-12-20T18:44:15Z

On 17/12/21 05:16PM, Miquel Raynal wrote:
> Create a spi_controller_mem_caps structure and put it within the
> spi_controller_mem_ops structure as these are highly related. So far the
> only field in this structure is the support for dtr operations, but soon
> we will add another parameter.
>
> Also create a helper to parse the capabilities and check if the
> requested capability has been set or not.
>
> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
> ---
> include/linux/spi/spi-mem.h | 13 +++++++++++++
> 1 file changed, 13 insertions(+)
>
> diff --git a/include/linux/spi/spi-mem.h b/include/linux/spi/spi-mem.h
> index 85e2ff7b840d..045ecb7c6f50 100644
> --- a/include/linux/spi/spi-mem.h
> +++ b/include/linux/spi/spi-mem.h
> @@ -220,6 +220,17 @@ static inline void *spi_mem_get_drvdata(struct spi_mem *mem)
> return mem->drvpriv;
> }
>
> +/**
> + * struct spi_controller_mem_caps - SPI memory controller capabilities
> + * @dtr: Supports DTR operations
> + */
> +struct spi_controller_mem_caps {
> + bool dtr;

I assume this would mean DTR is supported on _all_ phases? I am not sure
if we would ever need to encode DTR support per-phase, but that can
probably come later. Or the controller's supports_op() hook can do those
checks before calling spi_mem_default_supports_op().

> +};
> +
> +#define spi_mem_controller_is_capable(ctlr, cap) \
> + ((ctlr)->mem_ops->caps && (ctlr)->mem_ops->caps->cap) \
> +
> /**
> * struct spi_controller_mem_ops - SPI memory operations
> * @adjust_op_size: shrink the data xfer of an operation to match controller's
> @@ -253,6 +264,7 @@ static inline void *spi_mem_get_drvdata(struct spi_mem *mem)
> * @poll_status: poll memory device status until (status & mask) == match or
> * when the timeout has expired. It fills the data buffer with
> * the last status value.
> + * @caps: controller capabilities for the handling of the above operations.
> *
> * This interface should be implemented by SPI controllers providing an
> * high-level interface to execute SPI memory operation, which is usually the
> @@ -283,6 +295,7 @@ struct spi_controller_mem_ops {
> unsigned long initial_delay_us,
> unsigned long polling_rate_us,
> unsigned long timeout_ms);
> + const struct spi_controller_mem_caps *caps;

I feel like this would be better passed in as an argument to the
spi_mem_default_supports_op() function. But I see that Mark and you feel
differently so I won't insist on it.

> };
>
> /**
> --
> 2.27.0
>

--
Regards,
Pratyush Yadav
Texas Instruments Inc.