Re: [PATCH 1/2] clk: implement clk_get_enabled helper

[Ahmad Fatoum <a.fatoum@pengutronix.de>]

On 14.09.23 09:46, Sascha Hauer wrote:
> On Wed, Sep 13, 2023 at 02:08:06PM +0200, Ahmad Fatoum wrote:
>> Kernel code increasingly uses devm_clk_get_enabled to make driver code
>> more compact. Port a devres-less version to barebox to make porting such
>> Linux code easier.
>>
>> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
>> ---
>>  include/linux/clk.h | 29 +++++++++++++++++++++++++++++
>>  1 file changed, 29 insertions(+)
>>
>> diff --git a/include/linux/clk.h b/include/linux/clk.h
>> index 82022e78e39d..398427eca676 100644
>> --- a/include/linux/clk.h
>> +++ b/include/linux/clk.h
>> @@ -951,4 +951,33 @@ static inline struct clk *clk_get_optional(struct device *dev, const char *id)
>>  	return clk;
>>  }
>>  
>> +/**
>> + * clk_get_enabled - clk_get() + clk_prepare_enable()
>> + * @dev: device for clock "consumer"
>> + * @id: clock consumer ID
>> + *
>> + * Return: a struct clk corresponding to the clock producer, or
>> + * valid IS_ERR() condition containing errno.  The implementation
>> + * uses @dev and @id to determine the clock consumer, and thereby
>> + * the clock producer.  (IOW, @id may be identical strings, but
>> + * clk_get may return different clock producers depending on @dev.)
>> + *
>> + * The returned clk (if valid) is enabled.
>> + */
>> +static inline struct clk *clk_get_enabled(struct device *dev, const char *id)
>> +{
>> +	struct clk *clk;
>> +	int ret;
>> +
>> +	clk = clk_get(dev, id);
>> +	if (IS_ERR(clk))
>> +		return clk;
>> +
>> +	ret = clk_enable(clk);
>> +	if (ret)
>> +		return ERR_PTR(ret);
> 
> As this isn't devm managed you should release the clock in the error
> path.

clk_put is an empty stub in barebox and nearly all drivers just keep the clocks
on and let Linux worry about it. I think the helper is a net improvement,
even if it behaves a bit different.

Cheers,
Ahmad

> 
> Sascha
> 

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