mmc: core: Initiate suspend|resume from mmc bus instead of mmc host

The host should be responsible to suspend|resume the host and not the
card. This patch changes this behaviour, by moving the responsiblity
to the mmc bus instead which already holds the card device.

The exported functions mmc_suspend|resume_host are now to be considered
as depcrecated. Once all host drivers moves away from using them, we
can remove them. As of now, a successful error code is always returned.

Signed-off-by: Ulf Hansson <[e-mail]>
Tested-by: Jaehoon Chung <[e-mail]>
Signed-off-by: Chris Ball <[e-mail]>

drivers/mmc/core/bus.c

···
 {
 	struct mmc_driver *drv = to_mmc_driver(dev->driver);
 	struct mmc_card *card = mmc_dev_to_card(dev);
-	int ret = 0;
+	struct mmc_host *host = card->host;
+	int ret;
 
-	if (dev->driver && drv->suspend)
+	if (dev->driver && drv->suspend) {
 		ret = drv->suspend(card);
+		if (ret)
+			return ret;
+	}
+
+	ret = host->bus_ops->suspend(host);
 	return ret;
 }
 
···
 {
 	struct mmc_driver *drv = to_mmc_driver(dev->driver);
 	struct mmc_card *card = mmc_dev_to_card(dev);
-	int ret = 0;
+	struct mmc_host *host = card->host;
+	int ret;
+
+	ret = host->bus_ops->resume(host);
+	if (ret)
+		pr_warn("%s: error %d during resume (card was removed?)\n",
+			mmc_hostname(host), ret);
 
 	if (dev->driver && drv->resume)
 		ret = drv->resume(card);
+
 	return ret;
 }
 #endif

drivers/mmc/core/core.c

···
  */
 int mmc_suspend_host(struct mmc_host *host)
 {
-	int err = 0;
-
-	mmc_bus_get(host);
-	if (host->bus_ops && !host->bus_dead) {
-		if (host->bus_ops->suspend)
-			err = host->bus_ops->suspend(host);
-	}
-	mmc_bus_put(host);
-
-	return err;
+	/* This function is deprecated */
+	return 0;
 }
 EXPORT_SYMBOL(mmc_suspend_host);
 
···
  */
 int mmc_resume_host(struct mmc_host *host)
 {
-	int err;
-
-	mmc_bus_get(host);
-	if (host->bus_ops && !host->bus_dead) {
-		BUG_ON(!host->bus_ops->resume);
-		err = host->bus_ops->resume(host);
-		if (err)
-			pr_warning("%s: error %d during resume "
-					    "(card was removed?)\n",
-					    mmc_hostname(host), err);
-	}
-	mmc_bus_put(host);
-
+	/* This function is deprecated */
 	return 0;
 }
 EXPORT_SYMBOL(mmc_resume_host);