mmc: sdio: enable runtime PM for SDIO functions
Enable runtime PM for SDIO functions.
SDIO functions are initialized with a disabled runtime PM state,
and are set active (and their usage count is incremented)
only before potential drivers are probed.
SDIO function drivers that support runtime PM should call
pm_runtime_put_noidle() in their probe routine, and
pm_runtime_get_noresume() in their remove routine (very
similarly to PCI drivers).
In case a matching driver does not support runtime PM, power will
always be kept high (since the usage count is positive).
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Tested-by: Luciano Coelho <luciano.coelho@nokia.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
diff --git a/drivers/mmc/core/sdio_bus.c b/drivers/mmc/core/sdio_bus.c
index 256a968..3637483 100644
--- a/drivers/mmc/core/sdio_bus.c
+++ b/drivers/mmc/core/sdio_bus.c
@@ -126,21 +126,46 @@
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;
- return drv->probe(func, id);
+ ret = drv->probe(func, id);
+ if (ret)
+ goto disable_runtimepm;
+
+ 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);
@@ -152,7 +177,14 @@
sdio_release_host(func);
}
- return 0;
+ /* 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