drivers: nrf_qspi_nor: Prevent reading status before sending RDPD #64782
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After entering the Deep Power-down mode, some flash chips ignore all commands except from the one that releases the chip from the DP mode and it is not possible to successfully read their Status Register then. Since the QSPI peripheral tries to read this register when it is being activated, it consequently fails to send the actual command that would release the flash chip from the DP mode if that is to be done right after QSPI initialization. Prevent this problem by performing the QSPI activation with all pins disconnected. This causes that the Status Register value is read as all zeros and allows the activation to always finish successfully, and the RDPD command to be properly sent. Signed-off-by: Andrzej Głąbek <andrzej.glabek@nordicsemi.no>
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@de-nordic @nordicjm can you take a look? |
nordicjm
approved these changes
Nov 21, 2023
de-nordic
approved these changes
Nov 21, 2023
This was referenced Jan 14, 2024
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After entering the Deep Power-down mode, some flash chips ignore all commands except from the one that releases the chip from the DP mode and it is not possible to successfully read their Status Register then. Since the QSPI peripheral tries to read this register when it is being activated, it consequently fails to send the actual command that would release the flash chip from the DP mode if that is to be done right after QSPI initialization.
Prevent this problem by peforming the QSPI activation with all pins disconnected. This causes that the Status Register value is read as all zeros and allows the activation to always finish successfully, and the RDPD command to be properly sent.
Fixes #55543