@@ -344,6 +344,101 @@ unsigned int mmc_align_data_size(struct mmc_card *card, unsigned int sz)
EXPORT_SYMBOL(mmc_align_data_size);
/**
+ * mmc_host_enable - enable a host.
+ * @host: mmc host to enable
+ *
+ * Hosts that support power saving can use the 'enable' and 'disable'
+ * methods to exit and enter power saving states. For more information
+ * see comments for struct mmc_host_ops.
+ */
+int mmc_host_enable(struct mmc_host *host)
+{
+ if (!(host->caps & MMC_CAP_DISABLE))
+ return 0;
+
+ if (host->en_dis_recurs)
+ return 0;
+
+ if (host->nesting_cnt++)
+ return 0;
+
+ cancel_delayed_work_sync(&host->disable);
+
+ if (host->enabled)
+ return 0;
+
+ if (host->ops->enable) {
+ int err;
+
+ host->en_dis_recurs = 1;
+ err = host->ops->enable(host);
+ host->en_dis_recurs = 0;
+
+ if (err) {
+ pr_debug("%s: enable error %d\n",
+ mmc_hostname(host), err);
+ return err;
+ }
+ }
+ host->enabled = 1;
+ return 0;
+}
+EXPORT_SYMBOL(mmc_host_enable);
+
+static int mmc_host_do_disable(struct mmc_host *host, int lazy)
+{
+ if (host->ops->disable) {
+ int err;
+
+ host->en_dis_recurs = 1;
+ err = host->ops->disable(host, lazy);
+ host->en_dis_recurs = 0;
+
+ if (err < 0) {
+ pr_debug("%s: disable error %d\n",
+ mmc_hostname(host), err);
+ return err;
+ }
+ if (err > 0) {
+ unsigned long delay = msecs_to_jiffies(err);
+
+ mmc_schedule_delayed_work(&host->disable, delay);
+ }
+ }
+ host->enabled = 0;
+ return 0;
+}
+
+/**
+ * mmc_host_disable - disable a host.
+ * @host: mmc host to disable
+ *
+ * Hosts that support power saving can use the 'enable' and 'disable'
+ * methods to exit and enter power saving states. For more information
+ * see comments for struct mmc_host_ops.
+ */
+int mmc_host_disable(struct mmc_host *host)
+{
+ int err;
+
+ if (!(host->caps & MMC_CAP_DISABLE))
+ return 0;
+
+ if (host->en_dis_recurs)
+ return 0;
+
+ if (--host->nesting_cnt)
+ return 0;
+
+ if (!host->enabled)
+ return 0;
+
+ err = mmc_host_do_disable(host, 0);
+ return err;
+}
+EXPORT_SYMBOL(mmc_host_disable);
+
+/**
* __mmc_claim_host - exclusively claim a host
* @host: mmc host to claim
* @abort: whether or not the operation should be aborted
@@ -379,11 +474,81 @@ int __mmc_claim_host(struct mmc_host *host, atomic_t *abort)
wake_up(&host->wq);
spin_unlock_irqrestore(&host->lock, flags);
remove_wait_queue(&host->wq, &wait);
+ if (!stop)
+ mmc_host_enable(host);
return stop;
}
EXPORT_SYMBOL(__mmc_claim_host);
+static int mmc_try_claim_host(struct mmc_host *host)
+{
+ int claimed_host = 0;
+ unsigned long flags;
+
+ spin_lock_irqsave(&host->lock, flags);
+ if (!host->claimed) {
+ host->claimed = 1;
+ claimed_host = 1;
+ }
+ spin_unlock_irqrestore(&host->lock, flags);
+ return claimed_host;
+}
+
+static void mmc_do_release_host(struct mmc_host *host)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&host->lock, flags);
+ host->claimed = 0;
+ spin_unlock_irqrestore(&host->lock, flags);
+
+ wake_up(&host->wq);
+}
+
+void mmc_host_deeper_disable(struct work_struct *work)
+{
+ struct mmc_host *host =
+ container_of(work, struct mmc_host, disable.work);
+
+ /* If the host is claimed then we do not want to disable it anymore */
+ if (!mmc_try_claim_host(host))
+ return;
+ mmc_host_do_disable(host, 1);
+ mmc_do_release_host(host);
+}
+
+/**
+ * mmc_host_lazy_disable - lazily disable a host.
+ * @host: mmc host to disable
+ *
+ * Hosts that support power saving can use the 'enable' and 'disable'
+ * methods to exit and enter power saving states. For more information
+ * see comments for struct mmc_host_ops.
+ */
+int mmc_host_lazy_disable(struct mmc_host *host)
+{
+ if (!(host->caps & MMC_CAP_DISABLE))
+ return 0;
+
+ if (host->en_dis_recurs)
+ return 0;
+
+ if (--host->nesting_cnt)
+ return 0;
+
+ if (!host->enabled)
+ return 0;
+
+ if (host->disable_delay) {
+ mmc_schedule_delayed_work(&host->disable,
+ msecs_to_jiffies(host->disable_delay));
+ return 0;
+ } else
+ return mmc_host_do_disable(host, 1);
+}
+EXPORT_SYMBOL(mmc_host_lazy_disable);
+
/**
* mmc_release_host - release a host
* @host: mmc host to release
@@ -393,15 +558,11 @@ EXPORT_SYMBOL(__mmc_claim_host);
*/
void mmc_release_host(struct mmc_host *host)
{
- unsigned long flags;
-
WARN_ON(!host->claimed);
- spin_lock_irqsave(&host->lock, flags);
- host->claimed = 0;
- spin_unlock_irqrestore(&host->lock, flags);
+ mmc_host_lazy_disable(host);
- wake_up(&host->wq);
+ mmc_do_release_host(host);
}
EXPORT_SYMBOL(mmc_release_host);
@@ -947,6 +1108,8 @@ void mmc_stop_host(struct mmc_host *host)
spin_unlock_irqrestore(&host->lock, flags);
#endif
+ if (host->caps & MMC_CAP_DISABLE)
+ cancel_delayed_work(&host->disable);
cancel_delayed_work(&host->detect);
mmc_flush_scheduled_work();
@@ -975,6 +1138,8 @@ void mmc_stop_host(struct mmc_host *host)
*/
int mmc_suspend_host(struct mmc_host *host, pm_message_t state)
{
+ if (host->caps & MMC_CAP_DISABLE)
+ cancel_delayed_work(&host->disable);
cancel_delayed_work(&host->detect);
mmc_flush_scheduled_work();
@@ -83,6 +83,7 @@ struct mmc_host *mmc_alloc_host(int extra, struct device *dev)
spin_lock_init(&host->lock);
init_waitqueue_head(&host->wq);
INIT_DELAYED_WORK(&host->detect, mmc_rescan);
+ INIT_DELAYED_WORK_DEFERRABLE(&host->disable, mmc_host_deeper_disable);
/*
* By default, hosts do not support SGIO or large requests.
@@ -14,5 +14,7 @@
int mmc_register_host_class(void);
void mmc_unregister_host_class(void);
+void mmc_host_deeper_disable(struct work_struct *work);
+
#endif
@@ -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