Re: [PATCH 06/24] spi: dw: Support per spi-mem operation frequency switches

[Tudor Ambarus <tudor.ambarus@xxxxxxxxxx>]

On 10/25/24 5:14 PM, Miquel Raynal wrote:
> Every ->exec_op() call correctly configures the spi bus speed to the
> maximum allowed frequency for the memory using the constant spi default
> parameter. Since we can now have per-operation constraints, let's use
> the value that comes from the spi-mem operation structure instead. In
> case there is no specific limitation for this operation, the default spi
> device value will be given anyway.
> 
> The per-operation frequency capability is thus advertised to the spi-mem
> core.
> 
> Signed-off-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
> ---
>  drivers/spi/spi-dw-core.c | 10 ++++++++--
>  1 file changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/spi/spi-dw-core.c b/drivers/spi/spi-dw-core.c
> index 431788dd848c..3d49b1dbaed4 100644
> --- a/drivers/spi/spi-dw-core.c
> +++ b/drivers/spi/spi-dw-core.c
> @@ -677,7 +677,7 @@ static int dw_spi_exec_mem_op(struct spi_mem *mem, const struct spi_mem_op *op)
>  	 * operation. Transmit-only mode is suitable for the rest of them.
>  	 */
>  	cfg.dfs = 8;
> -	cfg.freq = clamp(mem->spi->max_speed_hz, 0U, dws->max_mem_freq);
> +	cfg.freq = clamp(op->max_freq, 0U, dws->max_mem_freq);
>  	if (op->data.dir == SPI_MEM_DATA_IN) {
>  		cfg.tmode = DW_SPI_CTRLR0_TMOD_EPROMREAD;
>  		cfg.ndf = op->data.nbytes;
> @@ -894,6 +894,10 @@ static void dw_spi_hw_init(struct device *dev, struct dw_spi *dws)
>  		dw_writel(dws, DW_SPI_CS_OVERRIDE, 0xF);
>  }
>  
> +static const struct spi_controller_mem_caps dw_spi_mem_caps = {
> +	.per_op_freq = true,
> +};
> +
>  int dw_spi_add_host(struct device *dev, struct dw_spi *dws)
>  {
>  	struct spi_controller *host;
> @@ -941,8 +945,10 @@ int dw_spi_add_host(struct device *dev, struct dw_spi *dws)
>  		host->set_cs = dw_spi_set_cs;
>  	host->transfer_one = dw_spi_transfer_one;
>  	host->handle_err = dw_spi_handle_err;
> -	if (dws->mem_ops.exec_op)
> +	if (dws->mem_ops.exec_op) {
>  		host->mem_ops = &dws->mem_ops;
> +		host->mem_caps = &dw_spi_mem_caps;

I guess you need a dws->mem_caps, otherwise you overwrite whatever the
layer above specifies.

> +	}
>  	host->max_speed_hz = dws->max_freq;
>  	host->flags = SPI_CONTROLLER_GPIO_SS;
>  	host->auto_runtime_pm = true;