mmc: sh_mmcif: maximize power saving

This patch uses runtime PM to allow the system to power down the MMC
controller, when the MMC closk is switched off.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>

1 files changed, 18 insertions, 9 deletions

diff --git a/drivers/mmc/host/sh_mmcif.c b/drivers/mmc/host/sh_mmcif.c
index 14f8edbaa195..557886bee9ce 100644
--- a/drivers/mmc/host/sh_mmcif.c
+++ b/drivers/mmc/host/sh_mmcif.c
@@ -175,6 +175,7 @@ struct sh_mmcif_host {
         enum mmcif_state state;
         spinlock_t lock;
         bool power;
+        bool card_present;
 
         /* DMA support */
         struct dma_chan         *chan_rx;
@@ -877,23 +878,23 @@ static void sh_mmcif_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
         spin_unlock_irqrestore(&host->lock, flags);
 
         if (ios->power_mode == MMC_POWER_UP) {
-                if (p->set_pwr)
-                        p->set_pwr(host->pd, ios->power_mode);
-                if (!host->power) {
+                if (!host->card_present) {
                         /* See if we also get DMA */
                         sh_mmcif_request_dma(host, host->pd->dev.platform_data);
-                        pm_runtime_get_sync(&host->pd->dev);
-                        host->power = true;
+                        host->card_present = true;
                 }
         } else if (ios->power_mode == MMC_POWER_OFF || !ios->clock) {
                 /* clock stop */
                 sh_mmcif_clock_control(host, 0);
                 if (ios->power_mode == MMC_POWER_OFF) {
-                        if (host->power) {
-                                pm_runtime_put(&host->pd->dev);
+                        if (host->card_present) {
                                 sh_mmcif_release_dma(host);
-                                host->power = false;
+                                host->card_present = false;
                         }
+                }
+                if (host->power) {
+                        pm_runtime_put(&host->pd->dev);
+                        host->power = false;
                         if (p->down_pwr)
                                 p->down_pwr(host->pd);
                 }
@@ -901,8 +902,16 @@ static void sh_mmcif_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
                 return;
         }
 
-        if (ios->clock)
+        if (ios->clock) {
+                if (!host->power) {
+                        if (p->set_pwr)
+                                p->set_pwr(host->pd, ios->power_mode);
+                        pm_runtime_get_sync(&host->pd->dev);
+                        host->power = true;
+                        sh_mmcif_sync_reset(host);
+                }
                 sh_mmcif_clock_control(host, ios->clock);
+        }
 
         host->bus_width = ios->bus_width;
         host->state = STATE_IDLE;