On Tue, Sep 16, 2025 at 03:56:43PM +0800, Haibo Chen wrote:
> For DTR mode, flexspi will automatically div 2 of the root clock
> and output to device. the formula is:
> device_clock = root_clock / (is_dtr ? 2 : 1);
>
> So correct the clock rate setting for DTR mode to get the max
> performance.
>
> Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
You can squash this to previous patch
This belong to add DTR support part.
Frank
> ---
> drivers/spi/spi-nxp-fspi.c | 9 +++++++--
> 1 file changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/spi/spi-nxp-fspi.c b/drivers/spi/spi-nxp-fspi.c
> index be1e56072b94f38af934556055e321d9834bb07b..15b094e8e892f0b61c1f320bba897fa1f588be91 100644
> --- a/drivers/spi/spi-nxp-fspi.c
> +++ b/drivers/spi/spi-nxp-fspi.c
> @@ -806,10 +806,15 @@ static void nxp_fspi_select_mem(struct nxp_fspi *f, struct spi_device *spi,
>
> nxp_fspi_select_rx_sample_clk_source(f, op_is_dtr);
>
> - if (op_is_dtr)
> + if (op_is_dtr) {
> f->flags |= FSPI_DTR_MODE;
> - else
> + /* For DTR mode, flexspi will default div 2 and output to device.
> + * so here to config the root clock to 2 * device rate.
> + */
> + rate = rate * 2;
> + } else {
> f->flags &= ~FSPI_DTR_MODE;
> + }
>
> nxp_fspi_clk_disable_unprep(f);
>
>
> --
> 2.34.1
>