sdhci: add regulator support

This patch adds support for regulator API to sdhci core driver.
Regulators can be used to disable power in suspended state to reduce
dissipated energy.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/mmc/host/sdhci.c

@@ -19,6 +19,7 @@
 #include <linux/dma-mapping.h>
 #include <linux/slab.h>
 #include <linux/scatterlist.h>
+#include <linux/regulator/consumer.h>
 
 #include <linux/leds.h>
 
@@ -1608,7 +1609,10 @@ int sdhci_suspend_host(struct sdhci_host *host, pm_message_t state)
 
 	free_irq(host->irq, host);
 
-	return 0;
+	if (host->vmmc)
+		ret = regulator_disable(host->vmmc);
+
+	return ret;
 }
 
 EXPORT_SYMBOL_GPL(sdhci_suspend_host);
@@ -1617,6 +1621,13 @@ int sdhci_resume_host(struct sdhci_host *host)
 {
 	int ret;
 
+	if (host->vmmc) {
+		int ret = regulator_enable(host->vmmc);
+		if (ret)
+			return ret;
+	}
+
+
 	if (host->flags & (SDHCI_USE_SDMA | SDHCI_USE_ADMA)) {
 		if (host->ops->enable_dma)
 			host->ops->enable_dma(host);
@@ -1889,6 +1900,14 @@ int sdhci_add_host(struct sdhci_host *host)
 	if (ret)
 		goto untasklet;
 
+	host->vmmc = regulator_get(mmc_dev(mmc), "vmmc");
+	if (IS_ERR(host->vmmc)) {
+		printk(KERN_INFO "%s: no vmmc regulator found\n", mmc_hostname(mmc));
+		host->vmmc = NULL;
+	} else {
+		regulator_enable(host->vmmc);
+	}
+
 	sdhci_init(host, 0);
 
 #ifdef CONFIG_MMC_DEBUG
@@ -1973,6 +1992,11 @@ void sdhci_remove_host(struct sdhci_host *host, int dead)
 	tasklet_kill(&host->card_tasklet);
 	tasklet_kill(&host->finish_tasklet);
 
+	if (host->vmmc) {
+		regulator_disable(host->vmmc);
+		regulator_put(host->vmmc);
+	}
+
 	kfree(host->adma_desc);
 	kfree(host->align_buffer);
 

drivers/mmc/host/sdhci.h

@@ -249,6 +249,8 @@ struct sdhci_host {
 
 	const struct sdhci_ops	*ops;		/* Low level hw interface */
 
+	struct regulator	*vmmc;		/* Power regulator */
+
 	/* Internal data */
 	struct mmc_host		*mmc;		/* MMC structure */
 	u64			dma_mask;	/* custom DMA mask */