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Subject: Re: [PATCH v2] eeprom: ee1004: Let device core handle attribute
 eeprom
From:   Heiner Kallweit <hkallweit1@gmail.com>
To:     Arnd Bergmann <arnd@arndb.de>,
        "Rafael J. Wysocki" <rafael@kernel.org>
Cc:     Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>
References: <66e9f6e5-fdee-6963-6131-228c69705350@gmail.com>
 <082be5db-46ef-6ddd-c33f-b30d5037a3f5@gmail.com>
Message-ID: <bfcc85e9-4f05-b407-6568-e605afc831e4@gmail.com>
Date:   Fri, 21 May 2021 20:43:57 +0200
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Greg added his Reviewed-by to v1, so you may disregard v2.

On 20.05.2021 21:25, Heiner Kallweit wrote:
> Instead of creating/removing the attribute ourselves, just declare the
> attribute and let the device core handle it. This allows to simplify
> the code.
> 
> Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
> ---
> v2:
> - open-code the proposed BIN_ATTRIBUTES_GROUPS macro
> I leave it to you which version you prefer.
> ---
>  drivers/misc/eeprom/ee1004.c | 30 +++++++++++++-----------------
>  1 file changed, 13 insertions(+), 17 deletions(-)
> 
> diff --git a/drivers/misc/eeprom/ee1004.c b/drivers/misc/eeprom/ee1004.c
> index 252e15ba6..d61acdaba 100644
> --- a/drivers/misc/eeprom/ee1004.c
> +++ b/drivers/misc/eeprom/ee1004.c
> @@ -89,7 +89,7 @@ static ssize_t ee1004_eeprom_read(struct i2c_client *client, char *buf,
>  	return status;
>  }
>  
> -static ssize_t ee1004_read(struct file *filp, struct kobject *kobj,
> +static ssize_t eeprom_read(struct file *filp, struct kobject *kobj,
>  			   struct bin_attribute *bin_attr,
>  			   char *buf, loff_t off, size_t count)
>  {
> @@ -160,15 +160,19 @@ static ssize_t ee1004_read(struct file *filp, struct kobject *kobj,
>  	return requested;
>  }
>  
> -static const struct bin_attribute eeprom_attr = {
> -	.attr = {
> -		.name = "eeprom",
> -		.mode = 0444,
> -	},
> -	.size = EE1004_EEPROM_SIZE,
> -	.read = ee1004_read,
> +static BIN_ATTR_RO(eeprom, EE1004_EEPROM_SIZE);
> +
> +static struct bin_attribute *ee1004_attrs[] = {
> +	&bin_attr_eeprom,
> +	NULL
> +};
> +
> +static const struct attribute_group ee1004_group = {
> +	.bin_attrs = ee1004_attrs,
>  };
>  
> +__ATTRIBUTE_GROUPS(ee1004);
> +
>  static int ee1004_probe(struct i2c_client *client,
>  			const struct i2c_device_id *id)
>  {
> @@ -222,11 +226,6 @@ static int ee1004_probe(struct i2c_client *client,
>  		ee1004_current_page);
>  	mutex_unlock(&ee1004_bus_lock);
>  
> -	/* Create the sysfs eeprom file */
> -	err = sysfs_create_bin_file(&client->dev.kobj, &eeprom_attr);
> -	if (err)
> -		goto err_clients_lock;
> -
>  	dev_info(&client->dev,
>  		 "%u byte EE1004-compliant SPD EEPROM, read-only\n",
>  		 EE1004_EEPROM_SIZE);
> @@ -237,8 +236,6 @@ static int ee1004_probe(struct i2c_client *client,
>  
>  	return 0;
>  
> - err_clients_lock:
> -	mutex_lock(&ee1004_bus_lock);
>   err_clients:
>  	if (--ee1004_dev_count == 0) {
>  		for (cnr--; cnr >= 0; cnr--) {
> @@ -255,8 +252,6 @@ static int ee1004_remove(struct i2c_client *client)
>  {
>  	int i;
>  
> -	sysfs_remove_bin_file(&client->dev.kobj, &eeprom_attr);
> -
>  	/* Remove page select clients if this is the last device */
>  	mutex_lock(&ee1004_bus_lock);
>  	if (--ee1004_dev_count == 0) {
> @@ -275,6 +270,7 @@ static int ee1004_remove(struct i2c_client *client)
>  static struct i2c_driver ee1004_driver = {
>  	.driver = {
>  		.name = "ee1004",
> +		.dev_groups = ee1004_groups,
>  	},
>  	.probe = ee1004_probe,
>  	.remove = ee1004_remove,
>