From 6b5691bdd8184cc0876d209c69d38844ea10f678 Mon Sep 17 00:00:00 2001
From: Ohad Ben-Cohen <ohad@wizery.com>
Date: Mon, 1 Nov 2010 09:41:44 +0200
Subject: [PATCH] mmc: add MMC_CAP_RUNTIME_PM

Some board/card/host configurations are not capable of powering off/on
on the card during runtime.

To support such configurations, and to allow smoother transition to
runtime PM behavior, MMC_CAP_RUNTIME_PM is added, so hosts need to
explicitly indicate that it's OK to power off their cards after boot.

This will prevent sdio_bus_probe() from failing to power on the card
when the driver is loaded on such setups.

Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
---
 drivers/mmc/core/sdio.c     |   37 +++++++++++++++++++++++--------------
 drivers/mmc/core/sdio_bus.c |   33 ++++++++++++++++++++++-----------
 include/linux/mmc/host.h    |    1 +
 3 files changed, 46 insertions(+), 25 deletions(-)

diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c
index 6a9ad40..373d56d 100644
--- a/drivers/mmc/core/sdio.c
+++ b/drivers/mmc/core/sdio.c
@@ -547,9 +547,11 @@ static void mmc_sdio_detect(struct mmc_host *host)
 	BUG_ON(!host->card);
 
 	/* Make sure card is powered before detecting it */
-	err = pm_runtime_get_sync(&host->card->dev);
-	if (err < 0)
-		goto out;
+	if (host->caps & MMC_CAP_RUNTIME_PM) {
+		err = pm_runtime_get_sync(&host->card->dev);
+		if (err < 0)
+			goto out;
+	}
 
 	mmc_claim_host(host);
 
@@ -570,7 +572,8 @@ out:
 	}
 
 	/* Tell PM core that we're done */
-	pm_runtime_put(&host->card->dev);
+	if (host->caps & MMC_CAP_RUNTIME_PM)
+		pm_runtime_put(&host->card->dev);
 }
 
 /*
@@ -720,16 +723,21 @@ int mmc_attach_sdio(struct mmc_host *host, u32 ocr)
 	card = host->card;
 
 	/*
-	 * Let runtime PM core know our card is active
+	 * Enable runtime PM only if supported by host+card+board
 	 */
-	err = pm_runtime_set_active(&card->dev);
-	if (err)
-		goto remove;
+	if (host->caps & MMC_CAP_RUNTIME_PM) {
+		/*
+		 * Let runtime PM core know our card is active
+		 */
+		err = pm_runtime_set_active(&card->dev);
+		if (err)
+			goto remove;
 
-	/*
-	 * Enable runtime PM for this card
-	 */
-	pm_runtime_enable(&card->dev);
+		/*
+		 * Enable runtime PM for this card
+		 */
+		pm_runtime_enable(&card->dev);
+	}
 
 	/*
 	 * The number of functions on the card is encoded inside
@@ -747,9 +755,10 @@ int mmc_attach_sdio(struct mmc_host *host, u32 ocr)
 			goto remove;
 
 		/*
-		 * Enable Runtime PM for this func
+		 * Enable Runtime PM for this func (if supported)
 		 */
-		pm_runtime_enable(&card->sdio_func[i]->dev);
+		if (host->caps & MMC_CAP_RUNTIME_PM)
+			pm_runtime_enable(&card->sdio_func[i]->dev);
 	}
 
 	mmc_release_host(host);
diff --git a/drivers/mmc/core/sdio_bus.c b/drivers/mmc/core/sdio_bus.c
index 2716c7a..f3ce21b 100644
--- a/drivers/mmc/core/sdio_bus.c
+++ b/drivers/mmc/core/sdio_bus.c
@@ -17,6 +17,7 @@
 #include <linux/pm_runtime.h>
 
 #include <linux/mmc/card.h>
+#include <linux/mmc/host.h>
 #include <linux/mmc/sdio_func.h>
 
 #include "sdio_cis.h"
@@ -132,9 +133,11 @@ static int sdio_bus_probe(struct device *dev)
 	 * it should call pm_runtime_put_noidle() in its probe routine and
 	 * pm_runtime_get_noresume() in its remove routine.
 	 */
-	ret = pm_runtime_get_sync(dev);
-	if (ret < 0)
-		goto out;
+	if (func->card->host->caps & MMC_CAP_RUNTIME_PM) {
+		ret = pm_runtime_get_sync(dev);
+		if (ret < 0)
+			goto out;
+	}
 
 	/* Set the default block size so the driver is sure it's something
 	 * sensible. */
@@ -151,7 +154,8 @@ static int sdio_bus_probe(struct device *dev)
 	return 0;
 
 disable_runtimepm:
-	pm_runtime_put_noidle(dev);
+	if (func->card->host->caps & MMC_CAP_RUNTIME_PM)
+		pm_runtime_put_noidle(dev);
 out:
 	return ret;
 }
@@ -160,12 +164,14 @@ static int sdio_bus_remove(struct device *dev)
 {
 	struct sdio_driver *drv = to_sdio_driver(dev->driver);
 	struct sdio_func *func = dev_to_sdio_func(dev);
-	int ret;
+	int ret = 0;
 
 	/* Make sure card is powered before invoking ->remove() */
-	ret = pm_runtime_get_sync(dev);
-	if (ret < 0)
-		goto out;
+	if (func->card->host->caps & MMC_CAP_RUNTIME_PM) {
+		ret = pm_runtime_get_sync(dev);
+		if (ret < 0)
+			goto out;
+	}
 
 	drv->remove(func);
 
@@ -178,10 +184,12 @@ static int sdio_bus_remove(struct device *dev)
 	}
 
 	/* First, undo the increment made directly above */
-	pm_runtime_put_noidle(dev);
+	if (func->card->host->caps & MMC_CAP_RUNTIME_PM)
+		pm_runtime_put_noidle(dev);
 
 	/* Then undo the runtime PM settings in sdio_bus_probe() */
-	pm_runtime_put_noidle(dev);
+	if (func->card->host->caps & MMC_CAP_RUNTIME_PM)
+		pm_runtime_put_noidle(dev);
 
 out:
 	return ret;
@@ -191,6 +199,8 @@ out:
 
 static int sdio_bus_pm_prepare(struct device *dev)
 {
+	struct sdio_func *func = dev_to_sdio_func(dev);
+
 	/*
 	 * Resume an SDIO device which was suspended at run time at this
 	 * point, in order to allow standard SDIO suspend/resume paths
@@ -212,7 +222,8 @@ static int sdio_bus_pm_prepare(struct device *dev)
 	 * since there is little point in failing system suspend if a
 	 * device can't be resumed.
 	 */
-	pm_runtime_resume(dev);
+	if (func->card->host->caps & MMC_CAP_RUNTIME_PM)
+		pm_runtime_resume(dev);
 
 	return 0;
 }
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index c3ffad8..e5eee0e 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -167,6 +167,7 @@ struct mmc_host {
 						/* DDR mode at 1.8V */
 #define MMC_CAP_1_2V_DDR	(1 << 12)	/* can support */
 						/* DDR mode at 1.2V */
+#define MMC_CAP_RUNTIME_PM	(1 << 13)	/* Can power off/on in runtime */
 
 	mmc_pm_flag_t		pm_caps;	/* supported pm features */
 
-- 
1.7.0.4
