3 files changed, 174 insertions, 6 deletions

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index e22d2b5576e..fb24a096dba 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -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);
@@ -953,6 +1114,8 @@ 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();
 
@@ -981,6 +1144,8 @@ 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();
 
diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c
index 5e945e64ead..a268d12f1af 100644
--- a/drivers/mmc/core/host.c
+++ b/drivers/mmc/core/host.c
@@ -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.
diff --git a/drivers/mmc/core/host.h b/drivers/mmc/core/host.h
index c2dc3d2d9f9..8c87e1109a3 100644
--- a/drivers/mmc/core/host.h
+++ b/drivers/mmc/core/host.h
@@ -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