1 files changed, 27 insertions, 5 deletions

diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 7ab962fa1d73..10a2080086ca 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -51,8 +51,30 @@ struct mmc_ios {
 
 struct mmc_host_ops {
         void    (*request)(struct mmc_host *host, struct mmc_request *req);
+        /*
+         * Avoid calling these three functions too often or in a "fast path",
+         * since underlaying controller might implement them in an expensive
+         * and/or slow way.
+         *
+         * Also note that these functions might sleep, so don't call them
+         * in the atomic contexts!
+         *
+         * Return values for the get_ro callback should be:
+         *   0 for a read/write card
+         *   1 for a read-only card
+         *   -ENOSYS when not supported (equal to NULL callback)
+         *   or a negative errno value when something bad happened
+         *
+         * Return values for the get_ro callback should be:
+         *   0 for a absent card
+         *   1 for a present card
+         *   -ENOSYS when not supported (equal to NULL callback)
+         *   or a negative errno value when something bad happened
+         */
         void    (*set_ios)(struct mmc_host *host, struct mmc_ios *ios);
         int     (*get_ro)(struct mmc_host *host);
+        int     (*get_cd)(struct mmc_host *host);
+
         void    (*enable_sdio_irq)(struct mmc_host *host, int enable);
 };
 
@@ -89,11 +111,11 @@ struct mmc_host {
         unsigned long           caps;           /* Host capabilities */
 
 #define MMC_CAP_4_BIT_DATA      (1 << 0)        /* Can the host do 4 bit transfers */
-#define MMC_CAP_MULTIWRITE      (1 << 1)        /* Can accurately report bytes sent to card on error */
-#define MMC_CAP_MMC_HIGHSPEED   (1 << 2)        /* Can do MMC high-speed timing */
-#define MMC_CAP_SD_HIGHSPEED    (1 << 3)        /* Can do SD high-speed timing */
-#define MMC_CAP_SDIO_IRQ        (1 << 4)        /* Can signal pending SDIO IRQs */
-#define MMC_CAP_SPI             (1 << 5)        /* Talks only SPI protocols */
+#define MMC_CAP_MMC_HIGHSPEED   (1 << 1)        /* Can do MMC high-speed timing */
+#define MMC_CAP_SD_HIGHSPEED    (1 << 2)        /* Can do SD high-speed timing */
+#define MMC_CAP_SDIO_IRQ        (1 << 3)        /* Can signal pending SDIO IRQs */
+#define MMC_CAP_SPI             (1 << 4)        /* Talks only SPI protocols */
+#define MMC_CAP_NEEDS_POLL      (1 << 5)        /* Needs polling for card-detection */
 
         /* host specific block data */
         unsigned int            max_seg_size;   /* see blk_queue_max_segment_size */