> when devfreq set one frequency, the final frequency may not
> the same as the requested frequency. Add get function in profile
> to let devfreq driver return the final frequency.
>
> Signed-off-by: Xiaoguang Chen <chenxg@xxxxxxxxxxx>
That is why in update_freq() function that you've modified uses:
err = devfreq->profile->target(devfreq->dev.parent, &freq, flags);
not
err = devfreq->profile->target(devfreq->dev.parent, freq, flags);
The target function will return the configured frequency right there.
Calling "__devfreq_get()" at the same location wouldn't help as long as
the "target()" callback is implemented correctly.
Cheers!
MyungJoo
> ---
> drivers/devfreq/devfreq.c | 12 +++++++++++-
> include/linux/devfreq.h | 2 ++
> 2 files changed, 13 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
> index 2144200..50a4fc0 100644
> --- a/drivers/devfreq/devfreq.c
> +++ b/drivers/devfreq/devfreq.c
> @@ -72,6 +72,16 @@ static struct devfreq *find_device_devfreq(struct device *dev)
> return ERR_PTR(-ENODEV);
> }
>
> +static unsigned long __devfreq_get(struct device *dev)
> +{
> + struct devfreq *devfreq = to_devfreq(dev);
> + unsigned long ret_freq = devfreq->previous_freq;
> + if (!devfreq->profile->get)
> + return ret_freq;
> + ret_freq = devfreq->profile->get(devfreq->dev.parent);
> + return ret_freq;
> +}
> +
> /**
> * update_devfreq() - Reevaluate the device and configure frequency.
> * @devfreq: the devfreq instance.
> @@ -116,7 +126,7 @@ int update_devfreq(struct devfreq *devfreq)
> if (err)
> return err;
>
> - devfreq->previous_freq = freq;
> + devfreq->previous_freq = __devfreq_get(&devfreq->dev);
> return err;
> }
>
> diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h
> index e5e4036..f789314 100644
> --- a/include/linux/devfreq.h
> +++ b/include/linux/devfreq.h
> @@ -65,6 +65,7 @@ struct devfreq_frequency_table {
> * @initial_freq The operating frequency when devfreq_add_device() is
> * called.
> * @polling_ms The polling interval in ms. 0 disables polling.
> + * @get Get the devices's actual frequency
> * @target The device should set its operating frequency at
> * freq or lowest-upper-than-freq value. If freq is
> * higher than any operable frequency, set maximum.
> @@ -84,6 +85,7 @@ struct devfreq_dev_profile {
> unsigned long initial_freq;
> unsigned int polling_ms;
>
> + unsigned long (*get)(struct device *dev);
> int (*target)(struct device *dev, unsigned long *freq, u32 flags);
> int (*get_dev_status)(struct device *dev,
> struct devfreq_dev_status *stat);
> --
> 1.7.0.4
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