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-rw-r--r--include/linux/mmc/host.h47
1 files changed, 47 insertions, 0 deletions
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 3e7615e9087e..338a9b3d51e4 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -51,6 +51,35 @@ struct mmc_ios {
};
struct mmc_host_ops {
+ /*
+ * Hosts that support power saving can use the 'enable' and 'disable'
+ * methods to exit and enter power saving states. 'enable' is called
+ * when the host is claimed and 'disable' is called (or scheduled with
+ * a delay) when the host is released. The 'disable' is scheduled if
+ * the disable delay set by 'mmc_set_disable_delay()' is non-zero,
+ * otherwise 'disable' is called immediately. 'disable' may be
+ * scheduled repeatedly, to permit ever greater power saving at the
+ * expense of ever greater latency to re-enable. Rescheduling is
+ * determined by the return value of the 'disable' method. A positive
+ * value gives the delay in milliseconds.
+ *
+ * In the case where a host function (like set_ios) may be called
+ * with or without the host claimed, enabling and disabling can be
+ * done directly and will nest correctly. Call 'mmc_host_enable()' and
+ * 'mmc_host_lazy_disable()' for this purpose, but note that these
+ * functions must be paired.
+ *
+ * Alternatively, 'mmc_host_enable()' may be paired with
+ * 'mmc_host_disable()' which calls 'disable' immediately. In this
+ * case the 'disable' method will be called with 'lazy' set to 0.
+ * This is mainly useful for error paths.
+ *
+ * Because lazy disable may be called from a work queue, the 'disable'
+ * method must claim the host when 'lazy' != 0, which will work
+ * correctly because recursion is detected and handled.
+ */
+ int (*enable)(struct mmc_host *host);
+ int (*disable)(struct mmc_host *host, int lazy);
void (*request)(struct mmc_host *host, struct mmc_request *req);
/*
* Avoid calling these three functions too often or in a "fast path",
@@ -118,6 +147,7 @@ struct mmc_host {
#define MMC_CAP_SPI (1 << 4) /* Talks only SPI protocols */
#define MMC_CAP_NEEDS_POLL (1 << 5) /* Needs polling for card-detection */
#define MMC_CAP_8_BIT_DATA (1 << 6) /* Can the host do 8 bit transfers */
+#define MMC_CAP_DISABLE (1 << 7) /* Can the host be disabled */
/* host specific block data */
unsigned int max_seg_size; /* see blk_queue_max_segment_size */
@@ -142,6 +172,13 @@ struct mmc_host {
unsigned int removed:1; /* host is being removed */
#endif
+ /* Only used with MMC_CAP_DISABLE */
+ int enabled; /* host is enabled */
+ int nesting_cnt; /* "enable" nesting count */
+ int en_dis_recurs; /* detect recursion */
+ unsigned int disable_delay; /* disable delay in msecs */
+ struct delayed_work disable; /* disabling work */
+
struct mmc_card *card; /* device attached to this host */
wait_queue_head_t wq;
@@ -197,5 +234,15 @@ struct regulator;
int mmc_regulator_get_ocrmask(struct regulator *supply);
int mmc_regulator_set_ocr(struct regulator *supply, unsigned short vdd_bit);
+int mmc_host_enable(struct mmc_host *host);
+int mmc_host_disable(struct mmc_host *host);
+int mmc_host_lazy_disable(struct mmc_host *host);
+
+static inline void mmc_set_disable_delay(struct mmc_host *host,
+ unsigned int disable_delay)
+{
+ host->disable_delay = disable_delay;
+}
+
#endif