mmc: tmio: support IP-builtin card detection logic
A card detect GPIO is set up only for platforms with "cd-gpios"
DT property or TMIO_MMC_USE_GPIO_CD flag. However, the driver
core always uses mmc_gpio_get_cd, which just fails with -ENOSYS
if ctx->cd_gpio is unset.
The bit 5 of the status register provides the current signal level
of the CD line. Allow to use it if the GPIO is unused.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>