mmc: sdhci: add IRQ wake up support

Don't disable SD Host IRQ during suspend if it is wake up source.
Enable wakeup event during suspend.

Signed-off-by: Jialing Fu <jlfu@marvell.com>
Signed-off-by: Kevin Liu <kliu5@marvell.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

drivers/mmc/host/sdhci.c

@@ -2458,6 +2458,32 @@ static irqreturn_t sdhci_irq(int irq, void *dev_id)
 \*****************************************************************************/
 
 #ifdef CONFIG_PM
+void sdhci_enable_irq_wakeups(struct sdhci_host *host)
+{
+	u8 val;
+	u8 mask = SDHCI_WAKE_ON_INSERT | SDHCI_WAKE_ON_REMOVE
+			| SDHCI_WAKE_ON_INT;
+
+	val = sdhci_readb(host, SDHCI_WAKE_UP_CONTROL);
+	val |= mask ;
+	/* Avoid fake wake up */
+	if (host->quirks & SDHCI_QUIRK_BROKEN_CARD_DETECTION)
+		val &= ~(SDHCI_WAKE_ON_INSERT | SDHCI_WAKE_ON_REMOVE);
+	sdhci_writeb(host, val, SDHCI_WAKE_UP_CONTROL);
+}
+EXPORT_SYMBOL_GPL(sdhci_enable_irq_wakeups);
+
+void sdhci_disable_irq_wakeups(struct sdhci_host *host)
+{
+	u8 val;
+	u8 mask = SDHCI_WAKE_ON_INSERT | SDHCI_WAKE_ON_REMOVE
+			| SDHCI_WAKE_ON_INT;
+
+	val = sdhci_readb(host, SDHCI_WAKE_UP_CONTROL);
+	val &= ~mask;
+	sdhci_writeb(host, val, SDHCI_WAKE_UP_CONTROL);
+}
+EXPORT_SYMBOL_GPL(sdhci_disable_irq_wakeups);
 
 int sdhci_suspend_host(struct sdhci_host *host)
 {
@@ -2487,9 +2513,13 @@ int sdhci_suspend_host(struct sdhci_host *host)
 		return ret;
 	}
 
-	sdhci_mask_irqs(host, SDHCI_INT_ALL_MASK);
-	free_irq(host->irq, host);
-
+	if (!device_may_wakeup(mmc_dev(host->mmc))) {
+		sdhci_mask_irqs(host, SDHCI_INT_ALL_MASK);
+		free_irq(host->irq, host);
+	} else {
+		sdhci_enable_irq_wakeups(host);
+		enable_irq_wake(host->irq);
+	}
 	return ret;
 }
 
@@ -2504,10 +2534,15 @@ int sdhci_resume_host(struct sdhci_host *host)
 			host->ops->enable_dma(host);
 	}
 
-	ret = request_irq(host->irq, sdhci_irq, IRQF_SHARED,
-			  mmc_hostname(host->mmc), host);
-	if (ret)
-		return ret;
+	if (!device_may_wakeup(mmc_dev(host->mmc))) {
+		ret = request_irq(host->irq, sdhci_irq, IRQF_SHARED,
+				  mmc_hostname(host->mmc), host);
+		if (ret)
+			return ret;
+	} else {
+		sdhci_disable_irq_wakeups(host);
+		disable_irq_wake(host->irq);
+	}
 
 	if ((host->mmc->pm_flags & MMC_PM_KEEP_POWER) &&
 	    (host->quirks2 & SDHCI_QUIRK2_HOST_OFF_CARD_ON)) {
@@ -2535,17 +2570,6 @@ int sdhci_resume_host(struct sdhci_host *host)
 }
 
 EXPORT_SYMBOL_GPL(sdhci_resume_host);
-
-void sdhci_enable_irq_wakeups(struct sdhci_host *host)
-{
-	u8 val;
-	val = sdhci_readb(host, SDHCI_WAKE_UP_CONTROL);
-	val |= SDHCI_WAKE_ON_INT;
-	sdhci_writeb(host, val, SDHCI_WAKE_UP_CONTROL);
-}
-
-EXPORT_SYMBOL_GPL(sdhci_enable_irq_wakeups);
-
 #endif /* CONFIG_PM */
 
 #ifdef CONFIG_PM_RUNTIME