mmc: sdio: add power_restore support

Add a power_restore handler to the SDIO bus ops,
in order to support waking up SDIO cards that
were powered off by runtime pm.

Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Tested-by: Luciano Coelho <luciano.coelho@nokia.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

drivers/mmc/core/sdio.c

@@ -638,11 +638,29 @@ static int mmc_sdio_resume(struct mmc_host *host)
 	return err;
 }
 
+static int mmc_sdio_power_restore(struct mmc_host *host)
+{
+	int ret;
+
+	BUG_ON(!host);
+	BUG_ON(!host->card);
+
+	mmc_claim_host(host);
+	ret = mmc_sdio_init_card(host, host->ocr, host->card,
+			(host->pm_flags & MMC_PM_KEEP_POWER));
+	if (!ret && host->sdio_irqs)
+		mmc_signal_sdio_irq(host);
+	mmc_release_host(host);
+
+	return ret;
+}
+
 static const struct mmc_bus_ops mmc_sdio_ops = {
 	.remove = mmc_sdio_remove,
 	.detect = mmc_sdio_detect,
 	.suspend = mmc_sdio_suspend,
 	.resume = mmc_sdio_resume,
+	.power_restore = mmc_sdio_power_restore,
 };