[PATCH v2 2/2] Add at24 based EEPROMs to the eeprom_dev hardware class

[PATCH v2 2/2] Add at24 based EEPROMs to the eeprom_dev hardware class

[Curt Brune]

During device instantiation have the at24 driver add the new device to
the eeprom_dev hardware class.  The functionality is enabled by
CONFIG_EEPROM_CLASS.

Signed-off-by: Curt Brune <curt@cumulusnetworks.com>
---
 drivers/misc/eeprom/at24.c |   20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
index d87f77f..07782ea 100644
--- a/drivers/misc/eeprom/at24.c
+++ b/drivers/misc/eeprom/at24.c
@@ -22,10 +22,14 @@
 #include <linux/jiffies.h>
 #include <linux/of.h>
 #include <linux/i2c.h>
 #include <linux/platform_data/at24.h>
 
+#ifdef CONFIG_EEPROM_CLASS
+#include <linux/eeprom_class.h>
+#endif
+
 /*
  * I2C EEPROMs from most vendors are inexpensive and mostly interchangeable.
  * Differences between different vendor product lines (like Atmel AT24C or
  * MicroChip 24LC, etc) won't much matter for typical read/write access.
  * There are also I2C RAM chips, likewise interchangeable. One example
@@ -66,10 +70,13 @@ struct at24_data {
 
 	u8 *writebuf;
 	unsigned write_max;
 	unsigned num_addresses;
 
+#ifdef CONFIG_EEPROM_CLASS
+	struct device *eeprom_dev;
+#endif
 	/*
 	 * Some chips tie up multiple I2C addresses; dummy devices reserve
 	 * them for us, and we'll use them with SMBus calls.
 	 */
 	struct i2c_client *client[];
@@ -619,10 +626,19 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id)
 
 	err = sysfs_create_bin_file(&client->dev.kobj, &at24->bin);
 	if (err)
 		goto err_clients;
 
+#ifdef CONFIG_EEPROM_CLASS
+	at24->eeprom_dev = eeprom_device_register(&client->dev);
+	if (IS_ERR(at24->eeprom_dev)) {
+		dev_err(&client->dev, "error registering eeprom device.\n");
+		err = PTR_ERR(at24->eeprom_dev);
+		goto err_clients;
+	}
+#endif
+
 	i2c_set_clientdata(client, at24);
 
 	dev_info(&client->dev, "%zu byte %s EEPROM, %s, %u bytes/write\n",
 		at24->bin.size, client->name,
 		writable ? "writable" : "read-only", at24->write_max);
@@ -656,10 +672,14 @@ static int at24_remove(struct i2c_client *client)
 	sysfs_remove_bin_file(&client->dev.kobj, &at24->bin);
 
 	for (i = 1; i < at24->num_addresses; i++)
 		i2c_unregister_device(at24->client[i]);
 
+#ifdef CONFIG_EEPROM_CLASS
+	eeprom_device_unregister(at24->eeprom_dev);
+#endif
+
 	return 0;
 }
 
 /*-------------------------------------------------------------------------*/
 
-- 
1.7.10.4

Re: [PATCH v2 2/2] Add at24 based EEPROMs to the eeprom_dev hardware class

[Igor Grinberg]

Hi Curt,

On 01/23/14 21:16, Curt Brune wrote:
> During device instantiation have the at24 driver add the new device to
> the eeprom_dev hardware class.  The functionality is enabled by
> CONFIG_EEPROM_CLASS.
> 
> Signed-off-by: Curt Brune <curt@cumulusnetworks.com>
> ---
>  drivers/misc/eeprom/at24.c |   20 ++++++++++++++++++++
>  1 file changed, 20 insertions(+)
> 
> diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
> index d87f77f..07782ea 100644
> --- a/drivers/misc/eeprom/at24.c
> +++ b/drivers/misc/eeprom/at24.c
> @@ -22,10 +22,14 @@
>  #include <linux/jiffies.h>
>  #include <linux/of.h>
>  #include <linux/i2c.h>
>  #include <linux/platform_data/at24.h>
>  
> +#ifdef CONFIG_EEPROM_CLASS
> +#include <linux/eeprom_class.h>
> +#endif

I would recommend moving the "ifdeffery" into the eeprom_class.h
and leave the users (in this case the at24.c) clean.

> +
>  /*
>   * I2C EEPROMs from most vendors are inexpensive and mostly interchangeable.
>   * Differences between different vendor product lines (like Atmel AT24C or
>   * MicroChip 24LC, etc) won't much matter for typical read/write access.
>   * There are also I2C RAM chips, likewise interchangeable. One example
> @@ -66,10 +70,13 @@ struct at24_data {
>  
>  	u8 *writebuf;
>  	unsigned write_max;
>  	unsigned num_addresses;
>  
> +#ifdef CONFIG_EEPROM_CLASS
> +	struct device *eeprom_dev;
> +#endif

Same here, this is just a pointer, so I don't think anyone has
a problem having it even if eeprom class is not selected.

>  	/*
>  	 * Some chips tie up multiple I2C addresses; dummy devices reserve
>  	 * them for us, and we'll use them with SMBus calls.
>  	 */
>  	struct i2c_client *client[];
> @@ -619,10 +626,19 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id)
>  
>  	err = sysfs_create_bin_file(&client->dev.kobj, &at24->bin);
>  	if (err)
>  		goto err_clients;
>  
> +#ifdef CONFIG_EEPROM_CLASS
> +	at24->eeprom_dev = eeprom_device_register(&client->dev);
> +	if (IS_ERR(at24->eeprom_dev)) {
> +		dev_err(&client->dev, "error registering eeprom device.\n");
> +		err = PTR_ERR(at24->eeprom_dev);
> +		goto err_clients;
> +	}
> +#endif

stub the eeprom_device_register() out in eeprom_class.h
for !CONFIG_EEPROM_CLASS case

> +
>  	i2c_set_clientdata(client, at24);
>  
>  	dev_info(&client->dev, "%zu byte %s EEPROM, %s, %u bytes/write\n",
>  		at24->bin.size, client->name,
>  		writable ? "writable" : "read-only", at24->write_max);
> @@ -656,10 +672,14 @@ static int at24_remove(struct i2c_client *client)
>  	sysfs_remove_bin_file(&client->dev.kobj, &at24->bin);
>  
>  	for (i = 1; i < at24->num_addresses; i++)
>  		i2c_unregister_device(at24->client[i]);
>  
> +#ifdef CONFIG_EEPROM_CLASS
> +	eeprom_device_unregister(at24->eeprom_dev);
> +#endif

same here.

> +
>  	return 0;
>  }
>  
>  /*-------------------------------------------------------------------------*/
>  
> 

-- 
Regards,
Igor.