PM / QoS: Make it possible to expose PM QoS device flags to user space

Define two device PM QoS flags, PM_QOS_FLAG_NO_POWER_OFF
and PM_QOS_FLAG_REMOTE_WAKEUP, and introduce routines
dev_pm_qos_expose_flags() and dev_pm_qos_hide_flags() allowing the
caller to expose those two flags to user space or to hide them
from it, respectively.

After the flags have been exposed, user space will see two
additional sysfs attributes, pm_qos_no_power_off and
pm_qos_remote_wakeup, under the device's /sys/devices/.../power/
directory.  Then, writing 1 to one of them will update the
PM QoS flags request owned by user space so that the corresponding
flag is requested to be set.  In turn, writing 0 to one of them
will cause the corresponding flag in the user space's request to
be cleared (however, the owners of the other PM QoS flags requests
for the same device may still request the flag to be set and it
may be effectively set even if user space doesn't request that).

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Jean Pihet <j-pihet@ti.com>
Acked-by: mark gross <markgross@thegnar.org>

1 files changed, 85 insertions, 9 deletions

diff --git a/drivers/base/power/sysfs.c b/drivers/base/power/sysfs.c
index 54c61ffa2044..50d16e3cb0a9 100644
--- a/drivers/base/power/sysfs.c
+++ b/drivers/base/power/sysfs.c
@@ -221,7 +221,7 @@ static DEVICE_ATTR(autosuspend_delay_ms, 0644, autosuspend_delay_ms_show,
 static ssize_t pm_qos_latency_show(struct device *dev,
                                    struct device_attribute *attr, char *buf)
 {
-        return sprintf(buf, "%d\n", dev->power.pq_req->data.pnode.prio);
+        return sprintf(buf, "%d\n", dev_pm_qos_requested_latency(dev));
 }
 
 static ssize_t pm_qos_latency_store(struct device *dev,
@@ -237,12 +237,66 @@ static ssize_t pm_qos_latency_store(struct device *dev,
         if (value < 0)
                 return -EINVAL;
 
-        ret = dev_pm_qos_update_request(dev->power.pq_req, value);
+        ret = dev_pm_qos_update_request(dev->power.qos->latency_req, value);
         return ret < 0 ? ret : n;
 }
 
 static DEVICE_ATTR(pm_qos_resume_latency_us, 0644,
                    pm_qos_latency_show, pm_qos_latency_store);
+
+static ssize_t pm_qos_no_power_off_show(struct device *dev,
+                                        struct device_attribute *attr,
+                                        char *buf)
+{
+        return sprintf(buf, "%d\n", !!(dev_pm_qos_requested_flags(dev)
+                                        & PM_QOS_FLAG_NO_POWER_OFF));
+}
+
+static ssize_t pm_qos_no_power_off_store(struct device *dev,
+                                         struct device_attribute *attr,
+                                         const char *buf, size_t n)
+{
+        int ret;
+
+        if (kstrtoint(buf, 0, &ret))
+                return -EINVAL;
+
+        if (ret != 0 && ret != 1)
+                return -EINVAL;
+
+        ret = dev_pm_qos_update_flags(dev, PM_QOS_FLAG_NO_POWER_OFF, ret);
+        return ret < 0 ? ret : n;
+}
+
+static DEVICE_ATTR(pm_qos_no_power_off, 0644,
+                   pm_qos_no_power_off_show, pm_qos_no_power_off_store);
+
+static ssize_t pm_qos_remote_wakeup_show(struct device *dev,
+                                         struct device_attribute *attr,
+                                         char *buf)
+{
+        return sprintf(buf, "%d\n", !!(dev_pm_qos_requested_flags(dev)
+                                        & PM_QOS_FLAG_REMOTE_WAKEUP));
+}
+
+static ssize_t pm_qos_remote_wakeup_store(struct device *dev,
+                                          struct device_attribute *attr,
+                                          const char *buf, size_t n)
+{
+        int ret;
+
+        if (kstrtoint(buf, 0, &ret))
+                return -EINVAL;
+
+        if (ret != 0 && ret != 1)
+                return -EINVAL;
+
+        ret = dev_pm_qos_update_flags(dev, PM_QOS_FLAG_REMOTE_WAKEUP, ret);
+        return ret < 0 ? ret : n;
+}
+
+static DEVICE_ATTR(pm_qos_remote_wakeup, 0644,
+                   pm_qos_remote_wakeup_show, pm_qos_remote_wakeup_store);
 #endif /* CONFIG_PM_RUNTIME */
 
 #ifdef CONFIG_PM_SLEEP
@@ -564,15 +618,27 @@ static struct attribute_group pm_runtime_attr_group = {
         .attrs  = runtime_attrs,
 };
 
-static struct attribute *pm_qos_attrs[] = {
+static struct attribute *pm_qos_latency_attrs[] = {
 #ifdef CONFIG_PM_RUNTIME
         &dev_attr_pm_qos_resume_latency_us.attr,
 #endif /* CONFIG_PM_RUNTIME */
         NULL,
 };
-static struct attribute_group pm_qos_attr_group = {
+static struct attribute_group pm_qos_latency_attr_group = {
         .name   = power_group_name,
-        .attrs  = pm_qos_attrs,
+        .attrs  = pm_qos_latency_attrs,
+};
+
+static struct attribute *pm_qos_flags_attrs[] = {
+#ifdef CONFIG_PM_RUNTIME
+        &dev_attr_pm_qos_no_power_off.attr,
+        &dev_attr_pm_qos_remote_wakeup.attr,
+#endif /* CONFIG_PM_RUNTIME */
+        NULL,
+};
+static struct attribute_group pm_qos_flags_attr_group = {
+        .name   = power_group_name,
+        .attrs  = pm_qos_flags_attrs,
 };
 
 int dpm_sysfs_add(struct device *dev)
@@ -615,14 +681,24 @@ void wakeup_sysfs_remove(struct device *dev)
         sysfs_unmerge_group(&dev->kobj, &pm_wakeup_attr_group);
 }
 
-int pm_qos_sysfs_add(struct device *dev)
+int pm_qos_sysfs_add_latency(struct device *dev)
+{
+        return sysfs_merge_group(&dev->kobj, &pm_qos_latency_attr_group);
+}
+
+void pm_qos_sysfs_remove_latency(struct device *dev)
+{
+        sysfs_unmerge_group(&dev->kobj, &pm_qos_latency_attr_group);
+}
+
+int pm_qos_sysfs_add_flags(struct device *dev)
 {
-        return sysfs_merge_group(&dev->kobj, &pm_qos_attr_group);
+        return sysfs_merge_group(&dev->kobj, &pm_qos_flags_attr_group);
 }
 
-void pm_qos_sysfs_remove(struct device *dev)
+void pm_qos_sysfs_remove_flags(struct device *dev)
 {
-        sysfs_unmerge_group(&dev->kobj, &pm_qos_attr_group);
+        sysfs_unmerge_group(&dev->kobj, &pm_qos_flags_attr_group);
 }
 
 void rpm_sysfs_remove(struct device *dev)