[PATCH 1/2] of: implement new of_device_ensured_probed_by_alias_stem

[Ahmad Fatoum]

On 15.03.22 15:16, Ahmad Fatoum wrote:
> Hello Andrej,
> 
> On 15.03.22 14:39, Andrej Picej wrote:
>> Function first goes through all the aliases which have the given stem.
>> It then ensures that all the devices hiding under these aliases are
>> probed.
>>
>> Signed-off-by: Andrej Picej <andrej.picej at norik.com>
>> ---
>>  drivers/of/base.c | 28 ++++++++++++++++++++++++++++
>>  include/of.h      |  6 ++++++
>>  2 files changed, 34 insertions(+)
>>
>> diff --git a/drivers/of/base.c b/drivers/of/base.c
>> index 80465d6d50..055dba97ab 100644
>> --- a/drivers/of/base.c
>> +++ b/drivers/of/base.c
>> @@ -274,6 +274,34 @@ int of_alias_get_id_from(struct device_node *root, struct device_node *np,
>>  }
>>  EXPORT_SYMBOL_GPL(of_alias_get_id_from);
>>  
>> +/**
>> + * of_device_ensured_probed_by_alias_stem - Ensure all devices with alias base name
>> + * are probed
>> + * @stem:	Alias stem of the given device_node
>> + *
>> + * The function ensures all devices with the given alias stem are probed.
>> + *
>> + * Returns 0 on success or error code.
>> + */
>> +int of_device_ensured_probed_by_alias_stem(const char *stem)
>> +{
>> +	struct alias_prop *app;
>> +	int id = -ENODEV;
>> +	int ret;
> 
> Can you early exit here if (!deep_probe_is_supported())?
> 
> This saves non-deep probe users the hassle of needless iteration
> and string comparisons.
> 
>> +
>> +	list_for_each_entry(app, &aliases_lookup, link) {

Corner case: aliases in DT are not sorted, so 

&{/aliases} { gpio1 = &pmic_gpio; gpio0 = &gpio1; };

may result in pmic_gpio being probed first..

Could be resolved by sorting aliases on insertion though. hmm..

>> +		if (of_node_cmp(app->stem, stem) != 0)
>> +			continue;
>> +
>> +		ret = of_device_ensure_probed(app->np);
>> +		if (ret)
>> +			return ret;
>> +	}
>> +
>> +	return 0;
>> +}
>> +EXPORT_SYMBOL_GPL(of_device_ensured_probed_by_alias_stem);
>> +
>>  const char *of_alias_get(struct device_node *np)
>>  {
>>  	struct alias_prop *app;
>> diff --git a/include/of.h b/include/of.h
>> index 216d0ee763..95817c58a4 100644
>> --- a/include/of.h
>> +++ b/include/of.h
>> @@ -261,6 +261,7 @@ extern void of_alias_scan(void);
>>  extern int of_alias_get_id(struct device_node *np, const char *stem);
>>  extern int of_alias_get_id_from(struct device_node *root, struct device_node *np,
>>  				const char *stem);
>> +extern int of_device_ensured_probed_by_alias_stem(const char *stem);
>>  extern const char *of_alias_get(struct device_node *np);
>>  extern int of_modalias_node(struct device_node *node, char *modalias, int len);
>>  
>> @@ -750,6 +751,11 @@ static inline int of_alias_get_id_from(struct device_node *root, struct device_n
>>  	return -ENOSYS;
>>  }
>>  
>> +static int of_device_ensured_probed_by_aliases(const char *stem)
>> +{
>> +	return -ENOSYS;
>> +}
>> +
>>  static inline const char *of_alias_get(struct device_node *np)
>>  {
>>  	return NULL;
> 
> 


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