Input: cyapa - add runtime power management support

This change implements runtime PM support in the driver and adds
runtime_suspend_scanrate_ms power management interface in device's power
group, so users or applications can control the runtime power management
strategy of trackpad device according to their requirements.

Signed-off-by: Dudley Du <dudl@cypress.com>
Tested-by: Jeremiah Mahler <jmmahler@gmail.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

diff --git a/drivers/input/mouse/cyapa.c b/drivers/input/mouse/cyapa.c
index 63f6646..3c72409 100644 (file)
--- a/drivers/input/mouse/cyapa.c
+++ b/drivers/input/mouse/cyapa.c
@@ -23,6 +23,7 @@
 #include <linux/mutex.h>
 #include <linux/slab.h>
 #include <linux/uaccess.h>
+#include <linux/pm_runtime.h>
 #include "cyapa.h"
 
 
@@ -357,6 +358,10 @@ static int cyapa_open(struct input_dev *input)
        }
 
        enable_irq(client->irq);
+       if (!pm_runtime_enabled(&client->dev)) {
+               pm_runtime_set_active(&client->dev);
+               pm_runtime_enable(&client->dev);
+       }
 out:
        mutex_unlock(&cyapa->state_sync_lock);
        return error;
@@ -370,6 +375,10 @@ static void cyapa_close(struct input_dev *input)
        mutex_lock(&cyapa->state_sync_lock);
 
        disable_irq(client->irq);
+       if (pm_runtime_enabled(&client->dev))
+               pm_runtime_disable(&client->dev);
+       pm_runtime_set_suspended(&client->dev);
+
        if (cyapa->operational)
                cyapa->ops->set_power_mode(cyapa, PWR_MODE_OFF, 0);
 
@@ -539,6 +548,9 @@ static int cyapa_reinitialize(struct cyapa *cyapa)
        struct input_dev *input = cyapa->input;
        int error;
 
+       if (pm_runtime_enabled(dev))
+               pm_runtime_disable(dev);
+
        /* Avoid command failures when TP was in OFF state. */
        if (cyapa->operational)
                cyapa->ops->set_power_mode(cyapa, PWR_MODE_FULL_ACTIVE, 0);
@@ -561,6 +573,13 @@ out:
                /* Reset to power OFF state to save power when no user open. */
                if (cyapa->operational)
                        cyapa->ops->set_power_mode(cyapa, PWR_MODE_OFF, 0);
+       } else if (!error && cyapa->operational) {
+               /*
+                * Make sure only enable runtime PM when device is
+                * in operational mode and input->users > 0.
+                */
+               pm_runtime_set_active(dev);
+               pm_runtime_enable(dev);
        }
 
        return error;
@@ -571,6 +590,7 @@ static irqreturn_t cyapa_irq(int irq, void *dev_id)
        struct cyapa *cyapa = dev_id;
        struct device *dev = &cyapa->client->dev;
 
+       pm_runtime_get_sync(dev);
        if (device_may_wakeup(dev))
                pm_wakeup_event(dev, 0);
 
@@ -601,6 +621,8 @@ static irqreturn_t cyapa_irq(int irq, void *dev_id)
        }
 
 out:
+       pm_runtime_mark_last_busy(dev);
+       pm_runtime_put_sync_autosuspend(dev);
        return IRQ_HANDLED;
 }
 
@@ -734,6 +756,127 @@ static inline int cyapa_prepare_wakeup_controls(struct cyapa *cyapa)
 }
 #endif /* CONFIG_PM_SLEEP */
 
+#ifdef CONFIG_PM
+static ssize_t cyapa_show_rt_suspend_scanrate(struct device *dev,
+                                             struct device_attribute *attr,
+                                             char *buf)
+{
+       struct cyapa *cyapa = dev_get_drvdata(dev);
+       u8 pwr_cmd;
+       u16 sleep_time;
+       int error;
+
+       error = mutex_lock_interruptible(&cyapa->state_sync_lock);
+       if (error)
+               return error;
+
+       pwr_cmd = cyapa->runtime_suspend_power_mode;
+       sleep_time = cyapa->runtime_suspend_sleep_time;
+
+       mutex_unlock(&cyapa->state_sync_lock);
+
+       return scnprintf(buf, PAGE_SIZE, "%u\n",
+                        cyapa->gen == CYAPA_GEN3 ?
+                               cyapa_pwr_cmd_to_sleep_time(pwr_cmd) :
+                               sleep_time);
+}
+
+static ssize_t cyapa_update_rt_suspend_scanrate(struct device *dev,
+                                               struct device_attribute *attr,
+                                               const char *buf, size_t count)
+{
+       struct cyapa *cyapa = dev_get_drvdata(dev);
+       u16 time;
+       int error;
+
+       if (buf == NULL || count == 0 || kstrtou16(buf, 10, &time)) {
+               dev_err(dev, "invalid runtime suspend scanrate ms parameter\n");
+               return -EINVAL;
+       }
+
+       /*
+        * When the suspend scanrate is changed, pm_runtime_get to resume
+        * a potentially suspended device, update to the new pwr_cmd
+        * and then pm_runtime_put to suspend into the new power mode.
+        */
+       pm_runtime_get_sync(dev);
+
+       error = mutex_lock_interruptible(&cyapa->state_sync_lock);
+       if (error)
+               return error;
+
+       cyapa->runtime_suspend_sleep_time = max_t(u16, time, 1000);
+       cyapa->runtime_suspend_power_mode =
+               cyapa_sleep_time_to_pwr_cmd(cyapa->runtime_suspend_sleep_time);
+
+       mutex_unlock(&cyapa->state_sync_lock);
+
+       pm_runtime_put_sync_autosuspend(dev);
+
+       return count;
+}
+
+static DEVICE_ATTR(runtime_suspend_scanrate_ms, S_IRUGO|S_IWUSR,
+                  cyapa_show_rt_suspend_scanrate,
+                  cyapa_update_rt_suspend_scanrate);
+
+static struct attribute *cyapa_power_runtime_entries[] = {
+       &dev_attr_runtime_suspend_scanrate_ms.attr,
+       NULL,
+};
+
+static const struct attribute_group cyapa_power_runtime_group = {
+       .name = power_group_name,
+       .attrs = cyapa_power_runtime_entries,
+};
+
+static void cyapa_remove_power_runtime_group(void *data)
+{
+       struct cyapa *cyapa = data;
+
+       sysfs_unmerge_group(&cyapa->client->dev.kobj,
+                               &cyapa_power_runtime_group);
+}
+
+static int cyapa_start_runtime(struct cyapa *cyapa)
+{
+       struct device *dev = &cyapa->client->dev;
+       int error;
+
+       cyapa->runtime_suspend_power_mode = PWR_MODE_IDLE;
+       cyapa->runtime_suspend_sleep_time =
+               cyapa_pwr_cmd_to_sleep_time(cyapa->runtime_suspend_power_mode);
+
+       error = sysfs_merge_group(&dev->kobj, &cyapa_power_runtime_group);
+       if (error) {
+               dev_err(dev,
+                       "failed to create power runtime group: %d\n", error);
+               return error;
+       }
+
+       error = devm_add_action(dev, cyapa_remove_power_runtime_group, cyapa);
+       if (error) {
+               cyapa_remove_power_runtime_group(cyapa);
+               dev_err(dev,
+                       "failed to add power runtime cleanup action: %d\n",
+                       error);
+               return error;
+       }
+
+       /* runtime is enabled until device is operational and opened. */
+       pm_runtime_set_suspended(dev);
+       pm_runtime_use_autosuspend(dev);
+       pm_runtime_set_autosuspend_delay(dev, AUTOSUSPEND_DELAY);
+
+       return 0;
+}
+#else
+static inline int cyapa_start_runtime(struct cyapa *cyapa)
+{
+       return 0;
+}
+#endif /* CONFIG_PM */
+
 static int cyapa_probe(struct i2c_client *client,
                       const struct i2c_device_id *dev_id)
 {
@@ -779,6 +922,12 @@ static int cyapa_probe(struct i2c_client *client,
                return error;
        }
 
+       error = cyapa_start_runtime(cyapa);
+       if (error) {
+               dev_err(dev, "failed to start pm_runtime: %d\n", error);
+               return error;
+       }
+
        error = devm_request_threaded_irq(dev, client->irq,
                                          NULL, cyapa_irq,
                                          IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
@@ -819,6 +968,13 @@ static int __maybe_unused cyapa_suspend(struct device *dev)
        if (error)
                return error;
 
+       /*
+        * Runtime PM is enable only when device is in operational mode and
+        * users in use, so need check it before disable it to
+        * avoid unbalance warning.
+        */
+       if (pm_runtime_enabled(dev))
+               pm_runtime_disable(dev);
        disable_irq(client->irq);
 
        /*
@@ -855,6 +1011,7 @@ static int __maybe_unused cyapa_resume(struct device *dev)
                cyapa->irq_wake = false;
        }
 
+       /* Update device states and runtime PM states. */
        error = cyapa_reinitialize(cyapa);
        if (error)
                dev_warn(dev, "failed to reinitialize TP device: %d\n", error);
@@ -865,7 +1022,36 @@ static int __maybe_unused cyapa_resume(struct device *dev)
        return 0;
 }
 
-static SIMPLE_DEV_PM_OPS(cyapa_pm_ops, cyapa_suspend, cyapa_resume);
+static int __maybe_unused cyapa_runtime_suspend(struct device *dev)
+{
+       struct cyapa *cyapa = dev_get_drvdata(dev);
+       int error;
+
+       error = cyapa->ops->set_power_mode(cyapa,
+                       cyapa->runtime_suspend_power_mode,
+                       cyapa->runtime_suspend_sleep_time);
+       if (error)
+               dev_warn(dev, "runtime suspend failed: %d\n", error);
+
+       return 0;
+}
+
+static int __maybe_unused cyapa_runtime_resume(struct device *dev)
+{
+       struct cyapa *cyapa = dev_get_drvdata(dev);
+       int error;
+
+       error = cyapa->ops->set_power_mode(cyapa, PWR_MODE_FULL_ACTIVE, 0);
+       if (error)
+               dev_warn(dev, "runtime resume failed: %d\n", error);
+
+       return 0;
+}
+
+static const struct dev_pm_ops cyapa_pm_ops = {
+       SET_SYSTEM_SLEEP_PM_OPS(cyapa_suspend, cyapa_resume)
+       SET_RUNTIME_PM_OPS(cyapa_runtime_suspend, cyapa_runtime_resume, NULL)
+};
 
 static const struct i2c_device_id cyapa_id_table[] = {
        { "cyapa", 0 },

diff --git a/drivers/input/mouse/cyapa.h b/drivers/input/mouse/cyapa.h
index 481a60d..51fcdb2 100644 (file)
--- a/drivers/input/mouse/cyapa.h
+++ b/drivers/input/mouse/cyapa.h
@@ -242,6 +242,8 @@ struct cyapa {
        /* power mode settings */
        u8 suspend_power_mode;
        u16 suspend_sleep_time;
+       u8 runtime_suspend_power_mode;
+       u16 runtime_suspend_sleep_time;
        u8 dev_pwr_mode;
        u16 dev_sleep_time;