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[PATCH v2 2/5] power: supply: core: add helper to get power supply given a fwnode

Amit Sunil Dhamne via B4 Relay posted 5 patches 7 months, 1 week ago
[PATCH v2 2/5] power: supply: core: add helper to get power supply given a fwnode
Posted by Amit Sunil Dhamne via B4 Relay 7 months, 1 week ago 
From: Amit Sunil Dhamne <amitsd@google.com>

Add a helper function power_supply_get_by_fwnode() to retrieve
power_supply given a valid fwnode reference.

Signed-off-by: Amit Sunil Dhamne <amitsd@google.com>
---
 drivers/power/supply/power_supply_core.c | 30 ++++++++++++++++++++++++++++++
 include/linux/power_supply.h             |  3 +++
 2 files changed, 33 insertions(+)

diff --git a/drivers/power/supply/power_supply_core.c b/drivers/power/supply/power_supply_core.c
index 76c340b38015af0a67a0d91305e6242a8646bf53..ef6ba22b837b0b9463f9a3065425e2720f40b9eb 100644
--- a/drivers/power/supply/power_supply_core.c
+++ b/drivers/power/supply/power_supply_core.c
@@ -496,6 +496,36 @@ struct power_supply *power_supply_get_by_name(const char *name)
 }
 EXPORT_SYMBOL_GPL(power_supply_get_by_name);
 
+static int power_supply_match_device_by_fwnode(struct device *dev, const void *data)
+{
+	return dev->parent && dev_fwnode(dev->parent) == data;
+}
+
+/**
+ * power_supply_get_by_fwnode() - Search for power supply given a fwnode ref.
+ * @fwnode: fwnode reference
+ *
+ * If power supply was found, it increases reference count for the internal
+ * power supply's device. The user should power_supply_put() after use.
+ *
+ * Return: Reference to power_supply node matching the fwnode on success or
+ * NULL on failure.
+ */
+struct power_supply *power_supply_get_by_fwnode(struct fwnode_handle *fwnode)
+{
+	struct power_supply *psy = NULL;
+	struct device *dev = class_find_device(&power_supply_class, NULL, fwnode,
+					       power_supply_match_device_by_fwnode);
+
+	if (dev) {
+		psy = dev_get_drvdata(dev);
+		atomic_inc(&psy->use_cnt);
+	}
+
+	return psy;
+}
+EXPORT_SYMBOL_GPL(power_supply_get_by_fwnode);
+
 /**
  * power_supply_put() - Drop reference obtained with power_supply_get_by_name
  * @psy: Reference to put
diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h
index 6ed53b292162469d7b357734d5589bff18a201d0..a35b08bd368e9305554e1a608dc8e526983cfa12 100644
--- a/include/linux/power_supply.h
+++ b/include/linux/power_supply.h
@@ -801,10 +801,13 @@ extern void power_supply_unreg_notifier(struct notifier_block *nb);
 #if IS_ENABLED(CONFIG_POWER_SUPPLY)
 extern struct power_supply *power_supply_get_by_name(const char *name);
 extern void power_supply_put(struct power_supply *psy);
+extern struct power_supply *power_supply_get_by_fwnode(struct fwnode_handle *fwnode);
 #else
 static inline void power_supply_put(struct power_supply *psy) {}
 static inline struct power_supply *power_supply_get_by_name(const char *name)
 { return NULL; }
+static inline struct power_supply *power_supply_get_by_fwnode(struct fwnode_handle *fwnode)
+{ return NULL; }
 #endif
 #ifdef CONFIG_OF
 extern struct power_supply *power_supply_get_by_phandle(struct device_node *np,

-- 
2.49.0.987.g0cc8ee98dc-goog
Re: [PATCH v2 2/5] power: supply: core: add helper to get power supply given a fwnode
Posted by Sebastian Reichel 5 months, 3 weeks ago 
Hi,

On Wed, May 07, 2025 at 06:00:23PM -0700, Amit Sunil Dhamne via B4 Relay wrote:
> From: Amit Sunil Dhamne <amitsd@google.com>
> 
> Add a helper function power_supply_get_by_fwnode() to retrieve
> power_supply given a valid fwnode reference.
> 
> Signed-off-by: Amit Sunil Dhamne <amitsd@google.com>
> ---
>  drivers/power/supply/power_supply_core.c | 30 ++++++++++++++++++++++++++++++
>  include/linux/power_supply.h             |  3 +++
>  2 files changed, 33 insertions(+)
> 
> diff --git a/drivers/power/supply/power_supply_core.c b/drivers/power/supply/power_supply_core.c
> index 76c340b38015af0a67a0d91305e6242a8646bf53..ef6ba22b837b0b9463f9a3065425e2720f40b9eb 100644
> --- a/drivers/power/supply/power_supply_core.c
> +++ b/drivers/power/supply/power_supply_core.c
> @@ -496,6 +496,36 @@ struct power_supply *power_supply_get_by_name(const char *name)
>  }
>  EXPORT_SYMBOL_GPL(power_supply_get_by_name);
>  
> +static int power_supply_match_device_by_fwnode(struct device *dev, const void *data)
> +{
> +	return dev->parent && dev_fwnode(dev->parent) == data;
> +}

This already exists as power_supply_match_device_fwnode().

> +
> +/**
> + * power_supply_get_by_fwnode() - Search for power supply given a fwnode ref.
> + * @fwnode: fwnode reference
> + *
> + * If power supply was found, it increases reference count for the internal
> + * power supply's device. The user should power_supply_put() after use.
> + *
> + * Return: Reference to power_supply node matching the fwnode on success or
> + * NULL on failure.
> + */
> +struct power_supply *power_supply_get_by_fwnode(struct fwnode_handle *fwnode)
> +{
> +	struct power_supply *psy = NULL;
> +	struct device *dev = class_find_device(&power_supply_class, NULL, fwnode,
> +					       power_supply_match_device_by_fwnode);
> +
> +	if (dev) {
> +		psy = dev_get_drvdata(dev);
> +		atomic_inc(&psy->use_cnt);
> +	}
> +
> +	return psy;
> +}
> +EXPORT_SYMBOL_GPL(power_supply_get_by_fwnode);

And this is a 50% of power_supply_get_by_reference(), so the
function should be updated to use power_supply_get_by_fwnode().

Greetings,

-- Sebastian

>  /**
>   * power_supply_put() - Drop reference obtained with power_supply_get_by_name
>   * @psy: Reference to put
> diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h
> index 6ed53b292162469d7b357734d5589bff18a201d0..a35b08bd368e9305554e1a608dc8e526983cfa12 100644
> --- a/include/linux/power_supply.h
> +++ b/include/linux/power_supply.h
> @@ -801,10 +801,13 @@ extern void power_supply_unreg_notifier(struct notifier_block *nb);
>  #if IS_ENABLED(CONFIG_POWER_SUPPLY)
>  extern struct power_supply *power_supply_get_by_name(const char *name);
>  extern void power_supply_put(struct power_supply *psy);
> +extern struct power_supply *power_supply_get_by_fwnode(struct fwnode_handle *fwnode);
>  #else
>  static inline void power_supply_put(struct power_supply *psy) {}
>  static inline struct power_supply *power_supply_get_by_name(const char *name)
>  { return NULL; }
> +static inline struct power_supply *power_supply_get_by_fwnode(struct fwnode_handle *fwnode)
> +{ return NULL; }
>  #endif
>  #ifdef CONFIG_OF
>  extern struct power_supply *power_supply_get_by_phandle(struct device_node *np,
> 
> -- 
> 2.49.0.987.g0cc8ee98dc-goog
> 
>
Re: [PATCH v2 2/5] power: supply: core: add helper to get power supply given a fwnode
Posted by Amit Sunil Dhamne 5 months, 1 week ago 
Hi Sebastian,

On 6/23/25 2:21 PM, Sebastian Reichel wrote:
> Hi,
>
> On Wed, May 07, 2025 at 06:00:23PM -0700, Amit Sunil Dhamne via B4 Relay wrote:
>> From: Amit Sunil Dhamne <amitsd@google.com>
>>
>> Add a helper function power_supply_get_by_fwnode() to retrieve
>> power_supply given a valid fwnode reference.
>>
>> Signed-off-by: Amit Sunil Dhamne <amitsd@google.com>
>> ---
>>   drivers/power/supply/power_supply_core.c | 30 ++++++++++++++++++++++++++++++
>>   include/linux/power_supply.h             |  3 +++
>>   2 files changed, 33 insertions(+)
>>
>> diff --git a/drivers/power/supply/power_supply_core.c b/drivers/power/supply/power_supply_core.c
>> index 76c340b38015af0a67a0d91305e6242a8646bf53..ef6ba22b837b0b9463f9a3065425e2720f40b9eb 100644
>> --- a/drivers/power/supply/power_supply_core.c
>> +++ b/drivers/power/supply/power_supply_core.c
>> @@ -496,6 +496,36 @@ struct power_supply *power_supply_get_by_name(const char *name)
>>   }
>>   EXPORT_SYMBOL_GPL(power_supply_get_by_name);
>>   
>> +static int power_supply_match_device_by_fwnode(struct device *dev, const void *data)
>> +{
>> +	return dev->parent && dev_fwnode(dev->parent) == data;
>> +}
> This already exists as power_supply_match_device_fwnode().

Thanks for your review! I will update in the next revision


>
>> +
>> +/**
>> + * power_supply_get_by_fwnode() - Search for power supply given a fwnode ref.
>> + * @fwnode: fwnode reference
>> + *
>> + * If power supply was found, it increases reference count for the internal
>> + * power supply's device. The user should power_supply_put() after use.
>> + *
>> + * Return: Reference to power_supply node matching the fwnode on success or
>> + * NULL on failure.
>> + */
>> +struct power_supply *power_supply_get_by_fwnode(struct fwnode_handle *fwnode)
>> +{
>> +	struct power_supply *psy = NULL;
>> +	struct device *dev = class_find_device(&power_supply_class, NULL, fwnode,
>> +					       power_supply_match_device_by_fwnode);
>> +
>> +	if (dev) {
>> +		psy = dev_get_drvdata(dev);
>> +		atomic_inc(&psy->use_cnt);
>> +	}
>> +
>> +	return psy;
>> +}
>> +EXPORT_SYMBOL_GPL(power_supply_get_by_fwnode);
> And this is a 50% of power_supply_get_by_reference(), so the
> function should be updated to use power_supply_get_by_fwnode().

Agreed.


Thanks,

Amit


>
> Greetings,
>
> -- Sebastian
>
>>   /**
>>    * power_supply_put() - Drop reference obtained with power_supply_get_by_name
>>    * @psy: Reference to put
>> diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h
>> index 6ed53b292162469d7b357734d5589bff18a201d0..a35b08bd368e9305554e1a608dc8e526983cfa12 100644
>> --- a/include/linux/power_supply.h
>> +++ b/include/linux/power_supply.h
>> @@ -801,10 +801,13 @@ extern void power_supply_unreg_notifier(struct notifier_block *nb);
>>   #if IS_ENABLED(CONFIG_POWER_SUPPLY)
>>   extern struct power_supply *power_supply_get_by_name(const char *name);
>>   extern void power_supply_put(struct power_supply *psy);
>> +extern struct power_supply *power_supply_get_by_fwnode(struct fwnode_handle *fwnode);
>>   #else
>>   static inline void power_supply_put(struct power_supply *psy) {}
>>   static inline struct power_supply *power_supply_get_by_name(const char *name)
>>   { return NULL; }
>> +static inline struct power_supply *power_supply_get_by_fwnode(struct fwnode_handle *fwnode)
>> +{ return NULL; }
>>   #endif
>>   #ifdef CONFIG_OF
>>   extern struct power_supply *power_supply_get_by_phandle(struct device_node *np,
>>
>> -- 
>> 2.49.0.987.g0cc8ee98dc-goog
>>
>>

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