3 files changed, 174 insertions, 6 deletions

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index e22d2b5576ec..fb24a096dba8 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 5e945e64ead7..a268d12f1af0 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 c2dc3d2d9f9a..8c87e1109a34 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