1 files changed, 83 insertions, 2 deletions

diff --git a/drivers/mmc/core/sdio_bus.c b/drivers/mmc/core/sdio_bus.c
index 4a890dcb95ab..2716c7ab6bbf 100644
--- a/drivers/mmc/core/sdio_bus.c
+++ b/drivers/mmc/core/sdio_bus.c
@@ -14,6 +14,7 @@
 #include <linux/device.h>
 #include <linux/err.h>
 #include <linux/slab.h>
+#include <linux/pm_runtime.h>
 
 #include <linux/mmc/card.h>
 #include <linux/mmc/sdio_func.h>
@@ -125,21 +126,46 @@ static int sdio_bus_probe(struct device *dev)
 	if (!id)
 		return -ENODEV;
 
+	/* Unbound SDIO functions are always suspended.
+	 * During probe, the function is set active and the usage count
+	 * is incremented.  If the driver supports runtime PM,
+	 * 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;
+
 	/* Set the default block size so the driver is sure it's something
 	 * sensible. */
 	sdio_claim_host(func);
 	ret = sdio_set_block_size(func, 0);
 	sdio_release_host(func);
 	if (ret)
-		return ret;
+		goto disable_runtimepm;
+
+	ret = drv->probe(func, id);
+	if (ret)
+		goto disable_runtimepm;
 
-	return drv->probe(func, id);
+	return 0;
+
+disable_runtimepm:
+	pm_runtime_put_noidle(dev);
+out:
+	return ret;
 }
 
 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;
+
+	/* Make sure card is powered before invoking ->remove() */
+	ret = pm_runtime_get_sync(dev);
+	if (ret < 0)
+		goto out;
 
 	drv->remove(func);
 
@@ -151,9 +177,63 @@ static int sdio_bus_remove(struct device *dev)
 		sdio_release_host(func);
 	}
 
+	/* First, undo the increment made directly above */
+	pm_runtime_put_noidle(dev);
+
+	/* Then undo the runtime PM settings in sdio_bus_probe() */
+	pm_runtime_put_noidle(dev);
+
+out:
+	return ret;
+}
+
+#ifdef CONFIG_PM_RUNTIME
+
+static int sdio_bus_pm_prepare(struct device *dev)
+{
+	/*
+	 * Resume an SDIO device which was suspended at run time at this
+	 * point, in order to allow standard SDIO suspend/resume paths
+	 * to keep working as usual.
+	 *
+	 * Ultimately, the SDIO driver itself will decide (in its
+	 * suspend handler, or lack thereof) whether the card should be
+	 * removed or kept, and if kept, at what power state.
+	 *
+	 * At this point, PM core have increased our use count, so it's
+	 * safe to directly resume the device. After system is resumed
+	 * again, PM core will drop back its runtime PM use count, and if
+	 * needed device will be suspended again.
+	 *
+	 * The end result is guaranteed to be a power state that is
+	 * coherent with the device's runtime PM use count.
+	 *
+	 * The return value of pm_runtime_resume is deliberately unchecked
+	 * since there is little point in failing system suspend if a
+	 * device can't be resumed.
+	 */
+	pm_runtime_resume(dev);
+
 	return 0;
 }
 
+static const struct dev_pm_ops sdio_bus_pm_ops = {
+	SET_RUNTIME_PM_OPS(
+		pm_generic_runtime_suspend,
+		pm_generic_runtime_resume,
+		pm_generic_runtime_idle
+	)
+	.prepare = sdio_bus_pm_prepare,
+};
+
+#define SDIO_PM_OPS_PTR	(&sdio_bus_pm_ops)
+
+#else /* !CONFIG_PM_RUNTIME */
+
+#define SDIO_PM_OPS_PTR	NULL
+
+#endif /* !CONFIG_PM_RUNTIME */
+
 static struct bus_type sdio_bus_type = {
 	.name		= "sdio",
 	.dev_attrs	= sdio_dev_attrs,
@@ -161,6 +241,7 @@ static struct bus_type sdio_bus_type = {
 	.uevent		= sdio_bus_uevent,
 	.probe		= sdio_bus_probe,
 	.remove		= sdio_bus_remove,
+	.pm		= SDIO_PM_OPS_PTR,
 };
 
 int sdio_register_bus(void)