Re: [PATCH 1/3] misc: at24: parse OF-data, too

[Grant Likely <grant.likely@secretlab.ca>]

On Wed, Nov 17, 2010 at 01:00:48PM +0100, Wolfram Sang wrote:
> Information about the pagesize and read-only-status may also come from
> the devicetree. Parse this data, too, and act accordingly. While we are
> here, change the initialization printout a bit. write_max is useful to
> know to detect performance bottlenecks, the rest is superfluous.
> 
> Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

Applied for -next, thanks.

g.

> ---
> 
> Changes since last version:
> 
> - use __be32 instead of u32
> 
>  Documentation/powerpc/dts-bindings/eeprom.txt |   28 +++++++++++++++++++++
>  drivers/misc/eeprom/at24.c                    |   33 ++++++++++++++++++++----
>  2 files changed, 55 insertions(+), 6 deletions(-)
>  create mode 100644 Documentation/powerpc/dts-bindings/eeprom.txt
> 
> diff --git a/Documentation/powerpc/dts-bindings/eeprom.txt b/Documentation/powerpc/dts-bindings/eeprom.txt
> new file mode 100644
> index 0000000..4342c10
> --- /dev/null
> +++ b/Documentation/powerpc/dts-bindings/eeprom.txt
> @@ -0,0 +1,28 @@
> +EEPROMs (I2C)
> +
> +Required properties:
> +
> +  - compatible : should be "<manufacturer>,<type>"
> +		 If there is no specific driver for <manufacturer>, a generic
> +		 driver based on <type> is selected. Possible types are:
> +		 24c00, 24c01, 24c02, 24c04, 24c08, 24c16, 24c32, 24c64,
> +		 24c128, 24c256, 24c512, 24c1024, spd
> +
> +  - reg : the I2C address of the EEPROM
> +
> +Optional properties:
> +
> +  - pagesize : the length of the pagesize for writing. Please consult the
> +               manual of your device, that value varies a lot. A wrong value
> +	       may result in data loss! If not specified, a safety value of
> +	       '1' is used which will be very slow.
> +
> +  - read-only: this parameterless property disables writes to the eeprom
> +
> +Example:
> +
> +eeprom@52 {
> +	compatible = "atmel,24c32";
> +	reg = <0x52>;
> +	pagesize = <32>;
> +};
> diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
> index 559b0b3..3a53efc 100644
> --- a/drivers/misc/eeprom/at24.c
> +++ b/drivers/misc/eeprom/at24.c
> @@ -20,6 +20,7 @@
>  #include <linux/log2.h>
>  #include <linux/bitops.h>
>  #include <linux/jiffies.h>
> +#include <linux/of.h>
>  #include <linux/i2c.h>
>  #include <linux/i2c/at24.h>
>  
> @@ -457,6 +458,27 @@ static ssize_t at24_macc_write(struct memory_accessor *macc, const char *buf,
>  
>  /*-------------------------------------------------------------------------*/
>  
> +#ifdef CONFIG_OF
> +static void at24_get_ofdata(struct i2c_client *client,
> +		struct at24_platform_data *chip)
> +{
> +	const __be32 *val;
> +	struct device_node *node = client->dev.of_node;
> +
> +	if (node) {
> +		if (of_get_property(node, "read-only", NULL))
> +			chip->flags |= AT24_FLAG_READONLY;
> +		val = of_get_property(node, "pagesize", NULL);
> +		if (val)
> +			chip->page_size = be32_to_cpup(val);
> +	}
> +}
> +#else
> +static void at24_get_ofdata(struct i2c_client *client,
> +		struct at24_platform_data *chip)
> +{ }
> +#endif /* CONFIG_OF */
> +
>  static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id)
>  {
>  	struct at24_platform_data chip;
> @@ -485,6 +507,9 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id)
>  		 */
>  		chip.page_size = 1;
>  
> +		/* update chipdata if OF is present */
> +		at24_get_ofdata(client, &chip);
> +
>  		chip.setup = NULL;
>  		chip.context = NULL;
>  	}
> @@ -597,19 +622,15 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id)
>  
>  	i2c_set_clientdata(client, at24);
>  
> -	dev_info(&client->dev, "%zu byte %s EEPROM %s\n",
> +	dev_info(&client->dev, "%zu byte %s EEPROM, %s, %u bytes/write\n",
>  		at24->bin.size, client->name,
> -		writable ? "(writable)" : "(read-only)");
> +		writable ? "writable" : "read-only", at24->write_max);
>  	if (use_smbus == I2C_SMBUS_WORD_DATA ||
>  	    use_smbus == I2C_SMBUS_BYTE_DATA) {
>  		dev_notice(&client->dev, "Falling back to %s reads, "
>  			   "performance will suffer\n", use_smbus ==
>  			   I2C_SMBUS_WORD_DATA ? "word" : "byte");
>  	}
> -	dev_dbg(&client->dev,
> -		"page_size %d, num_addresses %d, write_max %d, use_smbus %d\n",
> -		chip.page_size, num_addresses,
> -		at24->write_max, use_smbus);
>  
>  	/* export data to kernel code */
>  	if (chip.setup)
> -- 
> 1.7.2.3
>