5 files changed, 98 insertions, 3 deletions

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 30acd5265821..f4b97d3c3d0f 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -1151,6 +1151,9 @@ void mmc_stop_host(struct mmc_host *host)
 	cancel_delayed_work(&host->detect);
 	mmc_flush_scheduled_work();
 
+	/* clear pm flags now and let card drivers set them as needed */
+	host->pm_flags = 0;
+
 	mmc_bus_get(host);
 	if (host->bus_ops && !host->bus_dead) {
 		if (host->bus_ops->remove)
@@ -1273,12 +1276,13 @@ int mmc_suspend_host(struct mmc_host *host, pm_message_t state)
 			mmc_claim_host(host);
 			mmc_detach_bus(host);
 			mmc_release_host(host);
+			host->pm_flags = 0;
 			err = 0;
 		}
 	}
 	mmc_bus_put(host);
 
-	if (!err)
+	if (!err && !(host->pm_flags & MMC_PM_KEEP_POWER))
 		mmc_power_off(host);
 
 	return err;
@@ -1296,8 +1300,10 @@ int mmc_resume_host(struct mmc_host *host)
 
 	mmc_bus_get(host);
 	if (host->bus_ops && !host->bus_dead) {
-		mmc_power_up(host);
-		mmc_select_voltage(host, host->ocr);
+		if (!(host->pm_flags & MMC_PM_KEEP_POWER)) {
+			mmc_power_up(host);
+			mmc_select_voltage(host, host->ocr);
+		}
 		BUG_ON(!host->bus_ops->resume);
 		err = host->bus_ops->resume(host);
 		if (err) {
diff --git a/drivers/mmc/core/sdio_io.c b/drivers/mmc/core/sdio_io.c
index 87c618904ee2..ff27c8c71355 100644
--- a/drivers/mmc/core/sdio_io.c
+++ b/drivers/mmc/core/sdio_io.c
@@ -640,3 +640,52 @@ void sdio_f0_writeb(struct sdio_func *func, unsigned char b, unsigned int addr,
 		*err_ret = ret;
 }
 EXPORT_SYMBOL_GPL(sdio_f0_writeb);
+
+/**
+ *	sdio_get_host_pm_caps - get host power management capabilities
+ *	@func: SDIO function attached to host
+ *
+ *	Returns a capability bitmask corresponding to power management
+ *	features supported by the host controller that the card function
+ *	might rely upon during a system suspend.  The host doesn't need
+ *	to be claimed, nor the function active, for this information to be
+ *	obtained.
+ */
+mmc_pm_flag_t sdio_get_host_pm_caps(struct sdio_func *func)
+{
+	BUG_ON(!func);
+	BUG_ON(!func->card);
+
+	return func->card->host->pm_caps;
+}
+EXPORT_SYMBOL_GPL(sdio_get_host_pm_caps);
+
+/**
+ *	sdio_set_host_pm_flags - set wanted host power management capabilities
+ *	@func: SDIO function attached to host
+ *
+ *	Set a capability bitmask corresponding to wanted host controller
+ *	power management features for the upcoming suspend state.
+ *	This must be called, if needed, each time the suspend method of
+ *	the function driver is called, and must contain only bits that
+ *	were returned by sdio_get_host_pm_caps().
+ *	The host doesn't need to be claimed, nor the function active,
+ *	for this information to be set.
+ */
+int sdio_set_host_pm_flags(struct sdio_func *func, mmc_pm_flag_t flags)
+{
+	struct mmc_host *host;
+
+	BUG_ON(!func);
+	BUG_ON(!func->card);
+
+	host = func->card->host;
+
+	if (flags & ~host->pm_caps)
+		return -EINVAL;
+
+	/* function suspend methods are serialized, hence no lock needed */
+	host->pm_flags |= flags;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(sdio_set_host_pm_flags);
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index eaf36364b7d4..43eaf5ca5848 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -14,6 +14,7 @@
 #include <linux/sched.h>
 
 #include <linux/mmc/core.h>
+#include <linux/mmc/pm.h>
 
 struct mmc_ios {
 	unsigned int	clock;			/* clock rate */
@@ -152,6 +153,8 @@ struct mmc_host {
 #define MMC_CAP_NONREMOVABLE	(1 << 8)	/* Nonremovable e.g. eMMC */
 #define MMC_CAP_WAIT_WHILE_BUSY	(1 << 9)	/* Waits while card is busy */
 
+	mmc_pm_flag_t		pm_caps;	/* supported pm features */
+
 	/* host specific block data */
 	unsigned int		max_seg_size;	/* see blk_queue_max_segment_size */
 	unsigned short		max_hw_segs;	/* see blk_queue_max_hw_segments */
@@ -197,6 +200,8 @@ struct mmc_host {
 	struct task_struct	*sdio_irq_thread;
 	atomic_t		sdio_irq_thread_abort;
 
+	mmc_pm_flag_t		pm_flags;	/* requested pm features */
+
 #ifdef CONFIG_LEDS_TRIGGERS
 	struct led_trigger	*led;		/* activity led */
 #endif
diff --git a/include/linux/mmc/pm.h b/include/linux/mmc/pm.h
new file mode 100644
index 000000000000..d37aac49cf9a
--- /dev/null
+++ b/include/linux/mmc/pm.h
@@ -0,0 +1,30 @@
+/*
+ * linux/include/linux/mmc/pm.h
+ *
+ * Author:	Nicolas Pitre
+ * Copyright:	(C) 2009 Marvell Technology Group Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef LINUX_MMC_PM_H
+#define LINUX_MMC_PM_H
+
+/*
+ * These flags are used to describe power management features that
+ * some cards (typically SDIO cards) might wish to benefit from when
+ * the host system is being suspended.  There are several layers of
+ * abstractions involved, from the host controller driver, to the MMC core
+ * code, to the SDIO core code, to finally get to the actual SDIO function
+ * driver.  This file is therefore used for common definitions shared across
+ * all those layers.
+ */
+
+typedef unsigned int mmc_pm_flag_t;
+
+#define MMC_PM_KEEP_POWER	(1 << 0)	/* preserve card power during suspend */
+#define MMC_PM_WAKE_SDIO_IRQ	(1 << 1)	/* wake up host system on SDIO IRQ assertion */
+
+#endif
diff --git a/include/linux/mmc/sdio_func.h b/include/linux/mmc/sdio_func.h
index ac3ab683fec6..c6c0cceba5fe 100644
--- a/include/linux/mmc/sdio_func.h
+++ b/include/linux/mmc/sdio_func.h
@@ -15,6 +15,8 @@
 #include <linux/device.h>
 #include <linux/mod_devicetable.h>
 
+#include <linux/mmc/pm.h>
+
 struct mmc_card;
 struct sdio_func;
 
@@ -153,5 +155,8 @@ extern unsigned char sdio_f0_readb(struct sdio_func *func,
 extern void sdio_f0_writeb(struct sdio_func *func, unsigned char b,
 	unsigned int addr, int *err_ret);
 
+extern mmc_pm_flag_t sdio_get_host_pm_caps(struct sdio_func *func);
+extern int sdio_set_host_pm_flags(struct sdio_func *func, mmc_pm_flag_t flags);
+
 #endif