spi: spi-nxp-fspi: limit the clock rate for different sample clock source selection

[ Upstream commit f43579ef35 ]

For different sample clock source selection, the max frequency
flexspi supported are different. For mode 0, max frequency is 66MHz.
For mode 3, the max frequency is 166MHz.

Refer to 3.9.9 FlexSPI timing parameters on page 65.
https://www.nxp.com/docs/en/data-sheet/IMX8MNCEC.pdf

Though flexspi maybe still work under higher frequency, but can't
guarantee the stability. IC suggest to add this limitation on all
SoCs which contain flexspi.

Fixes: c07f270323 ("spi: spi-nxp-fspi: add the support for sample data from DQS pad")
Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
Link: https://patch.msgid.link/20250922-fspi-fix-v1-3-ff4315359d31@nxp.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Haibo Chen 2025-09-22 16:47:15 +08:00 • committed by Greg Kroah-Hartman
commit 13bd0ae13c