Is it possible to detect an SD card insertion / removal with a micro-SD socket with multiplexed CD / DAT3 line, in Linux on i.MX6 ?
CD/DAT3 card detection mechanism is workable on i.MX6, but there is no well-implementation of SDHC bus driver.
You can set uSDHCx_INT_STATUS_EN:CINSSEN, uSDHCx_INT_SIGNAL_EN:CINSIEN, and uSDHCx_PROT_CTRL:D3CD to enable CD/DAT3 card detection mechanism. Before that, you need to configure SD_DAT3 pad with pull-down.
But it's preferred to use mechanism switch(GPIO) for card detection, DAT3 is CS pin for SPI mode. A pull-down on this pin and CMD0 may set this card into the SPI mode.
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