Re: [PATCH v2 02/11] PM / devfreq: Remove devfreq_get_devfreq_by_phandle function

[Chanwoo Choi]

On 12/20/19 10:40 AM, Leonard Crestez wrote:
> On 2019-12-20 2:54 AM, Chanwoo Choi wrote:
>> On 12/20/19 9:46 AM, Leonard Crestez wrote:
>>> On 20.12.2019 02:18, Chanwoo Choi wrote:
>>>> Previously, devfreq core support 'devfreq' property in order to get
>>>> the devfreq device by phandle. But, 'devfreq' property name is not proper
>>>> on devicetree binding because this name doesn't mean the any h/w attribute.
>>>>
>>>> The devfreq core hand over the right to decide the property name
>>>> for getting the devfreq device on devicetree. Each devfreq driver
>>>> will decide the property name on devicetree binding and then get
>>>> the devfreq device by using devfreq_get_devfreq_by_node().
>>>>
>>>> Signed-off-by: Chanwoo Choi <cw00.choi@xxxxxxxxxxx>
>>>> ---
>>>>    drivers/devfreq/devfreq.c    | 35 -----------------------------------
>>>>    drivers/devfreq/exynos-bus.c | 12 +++++++++++-
>>>>    include/linux/devfreq.h      |  8 --------
>>>>    3 files changed, 11 insertions(+), 44 deletions(-)
>>>>
>>>> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
>>>> index cb8ca81c8973..c3d3c7c802a0 100644
>>>> --- a/drivers/devfreq/devfreq.c
>>>> +++ b/drivers/devfreq/devfreq.c
>>>> @@ -991,48 +991,13 @@ struct devfreq *devfreq_get_devfreq_by_node(struct device_node *node)
>>>>    
>>>>    	return ERR_PTR(-ENODEV);
>>>>    }
>>>> -
>>>> -/*
>>>> - * devfreq_get_devfreq_by_phandle - Get the devfreq device from devicetree
>>>> - * @dev - instance to the given device
>>>> - * @index - index into list of devfreq
>>>> - *
>>>> - * return the instance of devfreq device
>>>> - */
>>>> -struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev, int index)
>>>> -{
>>>> -	struct device_node *node;
>>>> -	struct devfreq *devfreq;
>>>> -
>>>> -	if (!dev)
>>>> -		return ERR_PTR(-EINVAL);
>>>> -
>>>> -	if (!dev->of_node)
>>>> -		return ERR_PTR(-EINVAL);
>>>> -
>>>> -	node = of_parse_phandle(dev->of_node, "devfreq", index);
>>>> -	if (!node)
>>>> -		return ERR_PTR(-ENODEV);
>>>> -
>>>> -	devfreq = devfreq_get_devfreq_by_node(node);
>>>> -	of_node_put(node);
>>>> -
>>>> -	return devfreq;
>>>> -}
>>>> -
>>>>    #else
>>>>    struct devfreq *devfreq_get_devfreq_by_node(struct device_node *node)
>>>>    {
>>>>    	return ERR_PTR(-ENODEV);
>>>>    }
>>>> -
>>>> -struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev, int index)
>>>> -{
>>>> -	return ERR_PTR(-ENODEV);
>>>> -}
>>>>    #endif /* CONFIG_OF */
>>>>    EXPORT_SYMBOL_GPL(devfreq_get_devfreq_by_node);
>>>> -EXPORT_SYMBOL_GPL(devfreq_get_devfreq_by_phandle);
>>>>    
>>>>    /**
>>>>     * devm_devfreq_remove_device() - Resource-managed devfreq_remove_device()
>>>> diff --git a/drivers/devfreq/exynos-bus.c b/drivers/devfreq/exynos-bus.c
>>>> index 7f5917d59072..1bc4e3c81115 100644
>>>> --- a/drivers/devfreq/exynos-bus.c
>>>> +++ b/drivers/devfreq/exynos-bus.c
>>>> @@ -86,6 +86,16 @@ static int exynos_bus_get_event(struct exynos_bus *bus,
>>>>    	return ret;
>>>>    }
>>>>    
>>>> +static struct devfreq *exynos_bus_get_parent_devfreq(struct device_node *np)
>>>> +{
>>>> +	struct device_node *node = of_parse_phandle(np, "devfreq", 0);
>>>> +
>>>> +	if (!node)
>>>> +		return ERR_PTR(-ENODEV);
>>>> +
>>>> +	return devfreq_get_devfreq_by_node(node);
>>>
>>> You need to call of_node_put(node) here and in several other places.
>>>
>>> The old devfreq_get_devfreq_by_phandle API handled this internally but
>>> devfreq_get_devfreq_by_node doesn't.
>>
>> Thanks. I'll fix it.
>>
>>>
>>> Maybe the _by_phandle API could be kept and just take the property name
>>> instead of always using "devfreq"?
>>
>> Do you mean like below?
>> devfreq_get_devfreq_by_phandle(struct device *dev, int index)
>> -> devfreq_get_devfreq_by_phandle(struct device *dev, char *property_name, int index)
>>
>> In case of devfreq-event.c,
>> struct devfreq_event_dev *devfreq_event_get_edev_by_phandle(
>> 						struct device *dev,
>> 						char property_name,
>> 						int index)
>> int devfreq_event_get_edev_count(struct device *dev, char *property_name)
> 
> Yes. These helpers would avoid the need for explicit of_node_put.

OK. Instead of removing devfreq_event_get_edev_by_phandle,
change the function property of devfreq_event_get_edev_by_phandle on v3.

After getting the review for dt-binding patch, I'll send v3 patches.

> 
>>
>>>
>>>> +}
>>>> +
>>>>    /*
>>>>     * devfreq function for both simple-ondemand and passive governor
>>>>     */
>>>> @@ -353,7 +363,7 @@ static int exynos_bus_profile_init_passive(struct exynos_bus *bus,
>>>>    	profile->exit = exynos_bus_passive_exit;
>>>>    
>>>>    	/* Get the instance of parent devfreq device */
>>>> -	parent_devfreq = devfreq_get_devfreq_by_phandle(dev, 0);
>>>> +	parent_devfreq = exynos_bus_get_parent_devfreq(dev->of_node);
>>>>    	if (IS_ERR(parent_devfreq))
>>>>    		return -EPROBE_DEFER;
>>>>    
>>>> diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h
>>>> index 1dccc47acbce..a4351698fb64 100644
>>>> --- a/include/linux/devfreq.h
>>>> +++ b/include/linux/devfreq.h
>>>> @@ -254,8 +254,6 @@ extern void devm_devfreq_unregister_notifier(struct device *dev,
>>>>    				struct notifier_block *nb,
>>>>    				unsigned int list);
>>>>    extern struct devfreq *devfreq_get_devfreq_by_node(struct device_node *node);
>>>> -extern struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev,
>>>> -						int index);
>>>>    
>>>>    #if IS_ENABLED(CONFIG_DEVFREQ_GOV_SIMPLE_ONDEMAND)
>>>>    /**
>>>> @@ -413,12 +411,6 @@ static inline struct devfreq *devfreq_get_devfreq_by_node(struct device_node *no
>>>>    	return ERR_PTR(-ENODEV);
>>>>    }
>>>>    
>>>> -static inline struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev,
>>>> -							int index)
>>>> -{
>>>> -	return ERR_PTR(-ENODEV);
>>>> -}
>>>> -
>>>>    static inline int devfreq_update_stats(struct devfreq *df)
>>>>    {
>>>>    	return -EINVAL;
> 
> 
> 


-- 
Best Regards,
Chanwoo Choi
Samsung Electronics