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>

2 files changed, 27 insertions, 1 deletions

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 70001ecb6ebe..c86c14af479f 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/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);
 
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index c98315c197ed..ff070a309f8d 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/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 */