Re: [PATCH v3 5/9] eeprom: Add bindings for simple eeprom framework

[Sascha Hauer <s.hauer@pengutronix.de>]

On Tue, Mar 24, 2015 at 10:30:30PM +0000, Srinivas Kandagatla wrote:
> This patch adds bindings for simple eeprom framework which allows eeprom
> consumers to talk to eeprom providers to get access to eeprom cell data.
> 
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> [Maxime Ripard: intial version of eeprom framework]
> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
> ---
>  .../devicetree/bindings/eeprom/eeprom.txt          | 70 ++++++++++++++++++++++
>  1 file changed, 70 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/eeprom/eeprom.txt
> 
> diff --git a/Documentation/devicetree/bindings/eeprom/eeprom.txt b/Documentation/devicetree/bindings/eeprom/eeprom.txt
> new file mode 100644
> index 0000000..8348d18
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/eeprom/eeprom.txt
> @@ -0,0 +1,70 @@
> += EEPROM Data Device Tree Bindings =
> +
> +This binding is intended to represent the location of hardware
> +configuration data stored in EEPROMs.
> +
> +On a significant proportion of boards, the manufacturer has stored
> +some data on an EEPROM-like device, for the OS to be able to retrieve
> +these information and act upon it. Obviously, the OS has to know
> +about where to retrieve these data from, and where they are stored on
> +the storage device.
> +
> +This document is here to document this.
> +
> += Data providers =
> +Contains bindings specific to provider drivers and data cells as children
> +to this node.
> +
> += Data cells =
> +These are the child nodes of the provider which contain data cell
> +information like offset and size in eeprom provider.
> +
> +Required properties:
> +reg:	specifies the offset in byte within that storage device, and the length
> +	in bytes of the data we care about.
> +	There could be more then one offset-length pairs in this property.
> +
> +Optional properties:
> +As required by specific data parsers/interpreters.
> +
> +For example:
> +
> +	/* Provider */
> +	qfprom: qfprom@00700000 {
> +		compatible 	= "qcom,qfprom";
> +		reg		= <0x00700000 0x1000>;
> +		...
> +
> +		/* Data cells */
> +		tsens_calibration: calib@404 {
> +			reg = <0x404 0x10>;
> +		};
> +
> +		serial_number: sn {
> +			reg = <0x104 0x4>, <0x204 0x4>, <0x30c 0x4>;
> +
> +		};
> +		...
> +	};
> +
> += Data consumers =
> +Are device nodes which consume eeprom data cells.
> +
> +Required properties:
> +
> +eeproms: List of phandle and data cell the device might be interested in.
> +
> +Optional properties:
> +
> +eeprom-names: List of data cell name strings sorted in the same order
> +	      as the eeproms property. Consumers drivers will use
> +	      eeprom-names to differentiate between multiple cells,
> +	      and hence being able to know what these cells are for.
> +
> +For example:
> +
> +	tsens {
> +		...
> +		eeproms = <&tsens_calibration>;
> +		eeprom-names = "calibration";
> +	};

This is somewhat complicated. Also having 'eeprom' in the binding is not
nice since it could be FRAM or something else. How about:

	tsens {
		calibration = <&tsens_calibration>;
	};


Sascha

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