Re: [RFC PATCH 4/4] sdio: pm: set device's power state after driver runtime suspended it

Rafael J. Wysocki
2012-10-19T18:08:38Z

On Friday 19 of October 2012 01:39:25 Rafael J. Wysocki wrote:
> On Friday 12 of October 2012 11:12:41 Aaron Lu wrote:
> > In sdio bus level runtime callback function, after call the driver's
> > runtime suspend callback, we will check if the device supports a
> > platform level power management, and if so, a proper power state is
> > chosen by the corresponding platform callback and then set.
> >
> > Platform level runtime wakeup is also set, if device is enabled for
> > runtime wakeup by its driver, it will be armed the ability to generate
> > a wakeup event by the platform.
> >
> > Signed-off-by: Aaron Lu <aaron.lu@intel.com>
> > ---
> > drivers/mmc/core/sdio_bus.c | 49 +++++++++++++++++++++++++++++++++++++++++++--
> > 1 file changed, 47 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/mmc/core/sdio_bus.c b/drivers/mmc/core/sdio_bus.c
> > index aaec9e2..d83dea8 100644
> > --- a/drivers/mmc/core/sdio_bus.c
> > +++ b/drivers/mmc/core/sdio_bus.c
> > @@ -23,6 +23,7 @@
> >
> > #include "sdio_cis.h"
> > #include "sdio_bus.h"
> > +#include "sdio.h"
> > #include "sdio_acpi.h"
> >
> > /* show configuration fields */
> > @@ -194,10 +195,54 @@ static int sdio_bus_remove(struct device *dev)
> > }
> >
> > #ifdef CONFIG_PM
> > +
> > +static int sdio_bus_runtime_suspend(struct device *dev)
> > +{
> > + int ret;
> > + sdio_power_t state;
> > +
> > + ret = pm_generic_runtime_suspend(dev);
> > + if (ret)
> > + goto out;
> > +
> > + if (!platform_sdio_power_manageable(dev))
> > + goto out;
> > +
> > + platform_sdio_run_wake(dev, true);
> > +
> > + state = platform_sdio_choose_power_state(dev);
> > + if (state == SDIO_POWER_ERROR) {
> > + ret = -EIO;
> > + goto out;
> > + }
> > +
> > + ret = platform_sdio_set_power_state(dev, state);
> > +
> > +out:
> > + return ret;
> > +}
> > +
> > +static int sdio_bus_runtime_resume(struct device *dev)
> > +{
> > + int ret;
> > +
> > + if (platform_sdio_power_manageable(dev)) {
> > + platform_sdio_run_wake(dev, false);
> > + ret = platform_sdio_set_power_state(dev, SDIO_D0);
> > + if (ret)
> > + goto out;
> > + }
> > +
> > + ret = pm_generic_runtime_resume(dev);
> > +
> > +out:
> > + return ret;
> > +}
> > +
>
> Most likely we will need to make analogous changes for other bus types that
> don't support power management natively, like platform, SPI, I2C etc. In all
> of them the _runtime_suspend() and _runtime_resume() routine will look
> almost exactly the same except for the platform_sdio_ prefix.
>
> For this reason, I think it would be better to simply define two functions
> acpi_pm_runtime_suspend() and acpi_pm_runtime_resume() that will do all of
> the ACPI-specific operations related to runtime suspend/resume. Then, we
> will be able to use these functions for all of the bus types in question
> in the same way (we may also need to add analogous functions for system
> suspend/resume handling).

Something like in the (totally untested) patch below.

With this code the SDIO bus type should be able to use
acpi_subsys_runtime_suspend() and acpi_subsys_runtime_resume() as its
bus-type-level runtime suspend/resume callback routines, respectively.

Thanks,
Rafael

Prototype, no sign-off.
---
drivers/acpi/dev_pm.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++
include/linux/acpi.h | 12 +++++++++++
2 files changed, 66 insertions(+)

Index: linux-pm/drivers/acpi/dev_pm.c
===================================================================
--- /dev/null
+++ linux-pm/drivers/acpi/dev_pm.c
@@ -0,0 +1,54 @@
+#include <linux/acpi.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/pm_qos.h>
+#include <linux/pm_runtime.h>
+
+#include <acpi/acpi_bus.h>
+
+int acpi_dev_runtime_suspend(struct device *dev)
+{
+ acpi_handle handle = DEVICE_ACPI_HANDLE(dev);
+ bool enable_wakeup;
+ int power_state;
+
+ if (!handle || !acpi_bus_power_manageable(handle))
+ return 0;
+
+ enable_wakeup = dev_pm_qos_flags(dev, PM_QOS_FLAG_REMOTE_WAKEUP))
+ != PM_QOS_FLAGS_NONE;
+ acpi_pm_device_run_wake(dev, enable_wakeup);
+
+ power_state = acpi_pm_device_sleep_state(dev, NULL, ACPI_STATE_D3);
+ if (power_state < ACPI_STATE_D0 || power_state > ACPI_STATE_D3)
+ return -EIO;
+
+ return acpi_bus_set_power(handle, power_state);
+}
+EXPORT_SYMBOL_GPL(acpi_dev_runtime_suspend);
+
+int acpi_dev_runtime_resume(struct device *dev)
+{
+ acpi_handle handle = DEVICE_ACPI_HANDLE(dev);
+
+ if (!handle || !acpi_bus_power_manageable(handle))
+ return 0;
+
+ acpi_pm_device_run_wake(dev, false);
+ return acpi_bus_set_power(handle, ACPI_STATE_D0);
+}
+EXPORT_SYMBOL_GPL(acpi_dev_runtime_resume);
+
+int acpi_subsys_runtime_suspend(struct device *dev)
+{
+ int ret = pm_generic_runtime_suspend(dev);
+ return ret ? ret : acpi_dev_runtime_suspend(dev);
+}
+EXPORT_SYMBOL_GPL(acpi_subsys_runtime_suspend);
+
+int acpi_subsys_runtime_resume(struct device *dev)
+{
+ int ret = acpi_dev_runtime_resume(dev);
+ return ret ? ret : pm_generic_runtime_resume(dev);
+}
+EXPORT_SYMBOL_GPL(acpi_subsys_runtime_resume);
Index: linux-pm/include/linux/acpi.h
===================================================================
--- linux-pm.orig/include/linux/acpi.h
+++ linux-pm/include/linux/acpi.h
@@ -434,4 +434,16 @@ acpi_status acpi_os_prepare_sleep(u8 sle
#define acpi_os_set_prepare_sleep(func, pm1a_ctrl, pm1b_ctrl) do { } while (0)
#endif

+#if defined(CONFIG_ACPI) && defined (CONFIG_PM_RUNTIME)
+int acpi_dev_runtime_suspend(struct device *dev);
+int acpi_dev_runtime_resume(struct device *dev);
+int acpi_subsys_runtime_suspend(struct device *dev);
+int acpi_subsys_runtime_resume(struct device *dev);
+#else
+static inline acpi_dev_runtime_suspend(struct device *dev) { return 0; }
+static inline acpi_dev_runtime_resume(struct device *dev) { return 0; }
+static inline acpi_subsys_runtime_suspend(struct device *dev) { return 0; }
+static inline acpi_subsys_runtime_resume(struct device *dev) { return 0; }
+#endif
+
#endif /*_LINUX_ACPI_H*/

--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.