mmc: add MMC_QUIRK_DISABLE_CD

006ebd5d introduced sdio_disable_cd(), which disconnects the pull-up
resistor on CD/DAT[3] (pin 1) of the card.

Make it possible to start using sdio_disable_cd() by introducing
MMC_QUIRK_DISABLE_CD.
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

drivers/mmc/core/sdio.c

@@ -187,7 +187,7 @@ static int sdio_disable_cd(struct mmc_card *card)
 	int ret;
 	u8 ctrl;
 
-	if (!card->cccr.disable_cd)
+	if (!mmc_card_disable_cd(card))
 		return 0;
 
 	ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_IF, 0, &ctrl);

include/linux/mmc/card.h

@@ -129,6 +129,7 @@ struct mmc_card {
 						/* (missing CIA registers) */
 #define MMC_QUIRK_BROKEN_CLK_GATING (1<<3)	/* clock gating the sdio bus will make card fail */
 #define MMC_QUIRK_NONSTD_FUNC_IF (1<<4)		/* SDIO card has nonstd function interfaces */
+#define MMC_QUIRK_DISABLE_CD	(1<<5)		/* disconnect CD/DAT[3] resistor */
 
 	unsigned int		erase_size;	/* erase size in sectors */
  	unsigned int		erase_shift;	/* if erase unit is power 2 */
@@ -184,6 +185,11 @@ static inline int mmc_blksz_for_byte_mode(const struct mmc_card *c)
 	return c->quirks & MMC_QUIRK_BLKSZ_FOR_BYTE_MODE;
 }
 
+static inline int mmc_card_disable_cd(const struct mmc_card *c)
+{
+	return c->quirks & MMC_QUIRK_DISABLE_CD;
+}
+
 static inline int mmc_card_nonstd_func_interface(const struct mmc_card *c)
 {
 	return c->quirks & MMC_QUIRK_NONSTD_FUNC_IF;