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drivers: memc_mcux_flexspi: force applying OVRDVAL #96957

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Merged
merged 1 commit into from
Oct 20, 2025
Merged

drivers: memc_mcux_flexspi: force applying OVRDVAL #96957

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23 changes: 23 additions & 0 deletions drivers/memc/Kconfig.mcux
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Original file line number Diff line number Diff line change
Expand Up @@ -56,6 +56,29 @@ config MEMC_MCUX_FLEXSPI_INIT_XIP
used for the FLEXSPI are compatible with those needed for XIP from
the flash device.

config FLASH_MCUX_FLEXSPI_FORCE_USING_OVRDVAL
bool "Force using the FLEXSPI Target Clock Delay Line Override Value"
help
Enable this setting to force using a specific raw value for the OVRDVAL
field in the DLLCR registers.

This option gives more granularity than the 'data-valid-time' field in
the dts. The unit of 'data-valid-time' is nanoseconds while the unit of
OVRDVAL are raw delay cells.

Normally the 'data-valid-time' on any 'nxp,imx-flexspi-device' device
will set the OVRDVAL and OVRDEN fields in the DLLCR register
but works only when the 'rx-clock-source' is configured to '#0 External
input from DQS pad' and the frequency <= 100MHz.

config FLASH_MCUX_FLEXSPI_OVRDVAL
int "FLEXSPI Target Clock Delay Line Override Value"
range 0 63
default 27
depends on FLASH_MCUX_FLEXSPI_FORCE_USING_OVRDVAL
help
Raw value to be stored in the DDLCR->OVRDVAL field.

config MEMC_MCUX_FLEXSPI
bool
select PINCTRL
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6 changes: 6 additions & 0 deletions drivers/memc/memc_mcux_flexspi.c
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Expand Up @@ -233,6 +233,12 @@ int memc_flexspi_set_device_config(const struct device *dev,
/* Lock IRQs before reconfiguring FlexSPI, to prevent XIP */
key = irq_lock();
FLEXSPI_SetFlashConfig(data->base, &tmp_config, port);

#if (CONFIG_FLASH_MCUX_FLEXSPI_FORCE_USING_OVRDVAL == 1)
data->base->DLLCR[port >> 1U] = FLEXSPI_DLLCR_OVRDEN(1) |
FLEXSPI_DLLCR_OVRDVAL(CONFIG_FLASH_MCUX_FLEXSPI_OVRDVAL);
#endif
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Hi @AndreHeinemans-NXP, May I ask about your motivation or a specific use case for proposing these changes?
In the function FLEXSPI_SetFlashConfig(), there is a mechanism that allows override and calculates the override value based on flexspirootclk.
Did you find that this function does not meet your use case requirements?

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You are referring to 'data-valid-time' which can be configured in the dts. I tried to use it but it seems that this field is only effective when rx-clock-source=3 (external DQS). See src. In the other cases, the boolean isUnifiedConfig will be set and results in having a default value being used.

I'm am working on the NavQ95 and currently there are some problems with the DQS signal. So I need to configure the rx-clock-source to 1 (Loopback from DQS pad). Within this mode it is not possible to get the correct value set by using the 'data-valid-time'.

Besides, it allows more granularity since the unit of 'data-valid-time' is nanoseconds while the unit of OVRDVAL are raw delay cells.

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Hi @AndreHeinemans-NXP, thank you for your explanations. It is clear to me.


FLEXSPI_UpdateLUT(data->base, data->port_luts[port].lut_offset,
lut_ptr, lut_count);
irq_unlock(key);
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