Re: [PATCH v16 04/12] input: cyapa: add runtime power management interfaces support for the device

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

Hi Dudley,

On Thu, Dec 18, 2014 at 06:00:48PM +0800, Dudley Du wrote:
> Add runtime_suspend_scanrate_ms power management interfaces in device's
> power group, so users or applications can control the runtime power
> management strategy of trackpad device as their requirements.
> TEST=test on Chromebooks.
> 
> Signed-off-by: Dudley Du <dudl@cypress.com>
> ---
>  drivers/input/mouse/cyapa.c | 171 +++++++++++++++++++++++++++++++++++++++++++-
>  drivers/input/mouse/cyapa.h |   4 ++
>  2 files changed, 174 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/input/mouse/cyapa.c b/drivers/input/mouse/cyapa.c
> index 73f6817..3bcfce3 100644
> --- 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"
>  
>  
> @@ -327,6 +328,8 @@ static int cyapa_open(struct input_dev *input)
>  	}
>  
>  	enable_irq(client->irq);
> +	pm_runtime_set_active(&client->dev);
> +	pm_runtime_enable(&client->dev);
>  out:
>  	mutex_unlock(&cyapa->state_sync_lock);
>  	return error;
> @@ -340,8 +343,10 @@ static void cyapa_close(struct input_dev *input)
>  	mutex_lock(&cyapa->state_sync_lock);
>  
>  	disable_irq(client->irq);
> +	pm_runtime_disable(&client->dev);
>  	if (!CYAPA_BOOTLOADER(cyapa) && cyapa->ops->set_power_mode)
>  		cyapa->ops->set_power_mode(cyapa, PWR_MODE_OFF, 0);
> +	pm_runtime_set_suspended(&client->dev);
>  
>  	mutex_unlock(&cyapa->state_sync_lock);
>  }
> @@ -542,6 +547,7 @@ static irqreturn_t cyapa_irq(int irq, void *dev_id)
>  	struct device *dev = &cyapa->client->dev;
>  	bool cont;
>  
> +	pm_runtime_get_sync(dev);
>  	if (device_may_wakeup(dev))
>  		pm_wakeup_event(dev, 0);
>  
> @@ -572,6 +578,8 @@ 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;
>  }
>  
> @@ -665,6 +673,116 @@ static void cyapa_remove_power_wakeup_group(void *data)
>  }
>  #endif /* CONFIG_PM_SLEEP */
>  
> +#ifdef CONFIG_PM_RUNTIME
> +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);
> +
> +	if (cyapa->gen == CYAPA_GEN3)
> +		return scnprintf(buf, PAGE_SIZE, "%u\n",
> +			cyapa_pwr_cmd_to_sleep_time(pwr_cmd));
> +	return scnprintf(buf, PAGE_SIZE, "%u\n", 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;
> +}
> +#endif /* CONFIG_PM_RUNTIME */
> +
>  static int cyapa_probe(struct i2c_client *client,
>  		       const struct i2c_device_id *dev_id)
>  {
> @@ -725,6 +843,14 @@ static int cyapa_probe(struct i2c_client *client,
>  	}
>  #endif /* CONFIG_PM_SLEEP */
>  
> +#ifdef CONFIG_PM_RUNTIME
> +	error = cyapa_start_runtime(cyapa);
> +	if (error) {
> +		dev_err(dev, "failed to start pm_runtime: %d\n", error);
> +		return error;
> +	}
> +#endif /* CONFIG_PM_RUNTIME */

Instead of using #ifdef here please provide a stub cyapa_start_runtime()
for cases when !CONFIG_PM_RUNTIME.

> +
>  	error = devm_request_threaded_irq(dev, client->irq,
>  					  NULL, cyapa_irq,
>  					  IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
> @@ -765,6 +891,7 @@ static int __maybe_unused cyapa_suspend(struct device *dev)
>  	if (error)
>  		return error;
>  
> +	pm_runtime_disable(dev);
>  	disable_irq(client->irq);
>  
>  	/*
> @@ -781,6 +908,8 @@ static int __maybe_unused cyapa_suspend(struct device *dev)
>  					error);
>  	}
>  
> +	pm_runtime_set_suspended(dev);
> +

I do not believe we should be touching runtime suspend state during
system state transition.

>  	if (device_may_wakeup(dev))
>  		cyapa->irq_wake = (enable_irq_wake(client->irq) == 0);
>  
> @@ -801,17 +930,57 @@ static int __maybe_unused cyapa_resume(struct device *dev)
>  		cyapa->irq_wake = false;
>  	}
>  
> +	pm_runtime_set_active(dev);
> +
>  	error = cyapa_reinitialize(cyapa);
>  	if (error)
>  		dev_warn(dev, "failed to reinitialize TP device: %d\n", error);
>  
>  	enable_irq(client->irq);
>  
> +	pm_runtime_enable(dev);
> +
>  	mutex_unlock(&cyapa->state_sync_lock);
>  	return 0;
>  }
>  
> -static SIMPLE_DEV_PM_OPS(cyapa_pm_ops, cyapa_suspend, cyapa_resume);
> +#ifdef CONFIG_PM_RUNTIME
> +static int cyapa_runtime_suspend(struct device *dev)
> +{
> +	struct cyapa *cyapa = dev_get_drvdata(dev);
> +	int error;
> +
> +	if (!CYAPA_BOOTLOADER(cyapa) && cyapa->ops->set_power_mode) {

Why do we need to check bootloader state? I'd rather we did not enable
runtime PM until we make sure device is out of bootloader.

> +		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 cyapa_runtime_resume(struct device *dev)
> +{
> +	struct cyapa *cyapa = dev_get_drvdata(dev);
> +	int error;
> +
> +	if (!CYAPA_BOOTLOADER(cyapa) && cyapa->ops->set_power_mode) {
> +		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;
> +}
> +#endif /* CONFIG_PM_RUNTIME */
> +
> +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 4c09be4..922a473 100644
> --- a/drivers/input/mouse/cyapa.h
> +++ b/drivers/input/mouse/cyapa.h
> @@ -253,6 +253,10 @@ struct cyapa {
>  	/* power mode settings */
>  	u8 suspend_power_mode;
>  	u16 suspend_sleep_time;
> +#ifdef CONFIG_PM_RUNTIME
> +	u8 runtime_suspend_power_mode;
> +	u16 runtime_suspend_sleep_time;
> +#endif /* CONFIG_PM_RUNTIME */
>  	u8 dev_pwr_mode;
>  	u16 dev_sleep_time;
>  
> -- 
> 1.9.1
> 

-- 
Dmitry