On Wed, Aug 24, 2011 at 1:22 AM, MyungJoo Ham <myungjoo.ham@xxxxxxxxxxx> wrote:
> - get_devfreq(): governors may convert struct dev -> struct devfreq
> - update_devfreq(): governors may notify DEVFREQ core to reevaluate
> frequencies.
> - Governors may have .init and .exit callbacks
>
> In order to use the internal interface, get_devfreq() and
> update_devfreq(), governor should include "governor.h"
>
> Signed-off-by: MyungJoo Ham <myungjoo.ham@xxxxxxxxxxx>
> Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
Please see patch 3 and 5 for my thoughts on locking in struct devfreq.
Also, this patch doesn't need to be separate, but can be rolled into
patch 3.
Regards,
Mike
> ---
> drivers/devfreq/devfreq.c | 32 ++++++++++++++++++++++++--------
> drivers/devfreq/governor.h | 20 ++++++++++++++++++++
> include/linux/devfreq.h | 2 ++
> 3 files changed, 46 insertions(+), 8 deletions(-)
> create mode 100644 drivers/devfreq/governor.h
>
> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
> index 5bbece6..8de3b21 100644
> --- a/drivers/devfreq/devfreq.c
> +++ b/drivers/devfreq/devfreq.c
> @@ -65,10 +65,10 @@ static struct devfreq *find_device_devfreq(struct device *dev)
>
> /**
> * get_devfreq() - find devfreq struct. a wrapped find_device_devfreq()
> - * with mutex protection.
> + * with mutex protection. exported for governors
> * @dev: device pointer used to lookup device devfreq.
> */
> -static struct devfreq *get_devfreq(struct device *dev)
> +struct devfreq *get_devfreq(struct device *dev)
> {
> struct devfreq *ret;
>
> @@ -113,17 +113,15 @@ static int devfreq_do(struct devfreq *devfreq)
> }
>
> /**
> - * devfreq_update() - Notify that the device OPP has been changed.
> - * @dev: the device whose OPP has been changed.
> + * update_devfreq() - Notify that the device OPP or frequency requirement
> + * has been changed. This function is exported for governors.
> + * @devfreq: the devfreq instance.
> */
> -static int devfreq_update(struct notifier_block *nb, unsigned long type,
> - void *devp)
> +int update_devfreq(struct devfreq *devfreq)
> {
> - struct devfreq *devfreq;
> int err = 0;
>
> mutex_lock(&devfreq_list_lock);
> - devfreq = container_of(nb, struct devfreq, nb);
> /* Reevaluate the proper frequency */
> err = devfreq_do(devfreq);
> mutex_unlock(&devfreq_list_lock);
> @@ -131,6 +129,18 @@ static int devfreq_update(struct notifier_block *nb, unsigned long type,
> }
>
> /**
> + * devfreq_update() - Notify that the device OPP has been changed.
> + * @dev: the device whose OPP has been changed.
> + */
> +static int devfreq_update(struct notifier_block *nb, unsigned long type,
> + void *devp)
> +{
> + struct devfreq *devfreq = container_of(nb, struct devfreq, nb);
> +
> + return update_devfreq(devfreq);
> +}
> +
> +/**
> * devfreq_monitor() - Periodically run devfreq_do()
> * @work: the work struct used to run devfreq_monitor periodically.
> *
> @@ -254,6 +264,9 @@ int devfreq_add_device(struct device *dev, struct devfreq_dev_profile *profile,
>
> list_add(&devfreq->node, &devfreq_list);
>
> + if (governor->init)
> + governor->init(devfreq);
> +
> if (devfreq_wq && devfreq->next_polling && !polling) {
> polling = true;
> queue_delayed_work(devfreq_wq, &devfreq_work,
> @@ -295,6 +308,9 @@ int devfreq_remove_device(struct device *dev)
>
> sysfs_unmerge_group(&dev->kobj, &dev_attr_group);
>
> + if (devfreq->governor->exit)
> + devfreq->governor->exit(devfreq);
> +
> list_del(&devfreq->node);
> srcu_notifier_chain_unregister(nh, &devfreq->nb);
> kfree(devfreq);
> diff --git a/drivers/devfreq/governor.h b/drivers/devfreq/governor.h
> new file mode 100644
> index 0000000..bb5d964
> --- /dev/null
> +++ b/drivers/devfreq/governor.h
> @@ -0,0 +1,20 @@
> +/*
> + * governor.h - internal header for governors.
> + *
> + * Copyright (C) 2011 Samsung Electronics
> + * MyungJoo Ham <myungjoo.ham@xxxxxxxxxxx>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + * This header is for devfreq governors in drivers/devfreq/
> + */
> +
> +#ifndef _GOVERNOR_H
> +#define _GOVERNOR_H
> +
> +extern struct devfreq *get_devfreq(struct device *dev);
> +extern int update_devfreq(struct devfreq *devfreq);
> +
> +#endif /* _GOVERNOR_H */
> diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h
> index 8252238..fdc6916 100644
> --- a/include/linux/devfreq.h
> +++ b/include/linux/devfreq.h
> @@ -46,6 +46,8 @@ struct devfreq_dev_profile {
> struct devfreq_governor {
> char name[DEVFREQ_NAME_LEN];
> int (*get_target_freq)(struct devfreq *this, unsigned long *freq);
> + int (*init)(struct devfreq *this);
> + void (*exit)(struct devfreq *this);
> };
>
> /**
> --
> 1.7.4.1
>
>
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