mmc: core: Extend shutdown sequence to handle bus operations

By adding an optional .shutdown callback to the bus_ops struct we
provide the possibility to let each bus type handle it's shutdown
requirements.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NChris Ball <cjb@laptop.org>

drivers/mmc/core/bus.c

@@ -126,8 +126,17 @@ static void mmc_bus_shutdown(struct device *dev)
 {
 	struct mmc_driver *drv = to_mmc_driver(dev->driver);
 	struct mmc_card *card = mmc_dev_to_card(dev);
+	struct mmc_host *host = card->host;
+	int ret;
 
 	drv->shutdown(card);
+
+	if (host->bus_ops->shutdown) {
+		ret = host->bus_ops->shutdown(host);
+		if (ret)
+			pr_warn("%s: error %d during shutdown\n",
+				mmc_hostname(host), ret);
+	}
 }
 
 #ifdef CONFIG_PM_SLEEP

drivers/mmc/core/core.h

@@ -26,6 +26,7 @@ struct mmc_bus_ops {
 	int (*power_save)(struct mmc_host *);
 	int (*power_restore)(struct mmc_host *);
 	int (*alive)(struct mmc_host *);
+	int (*shutdown)(struct mmc_host *);
 };
 
 void mmc_attach_bus(struct mmc_host *host, const struct mmc_bus_ops *ops);