Re: [PATCH 1/4] dt-bindings: nvmem: Add STM32 factory-programmed romem

[Rob Herring]

On Wed, Jan 30, 2019 at 05:38:53PM +0100, Fabrice Gasnier wrote:
> Add documentation for STMicroelectronics STM32 Factory-programmed
> read only memory area.
> 
> Signed-off-by: Fabrice Gasnier <fabrice.gasnier@xxxxxx>
> ---
>  .../devicetree/bindings/nvmem/st,stm32-romem.txt   | 31 ++++++++++++++++++++++
>  1 file changed, 31 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/nvmem/st,stm32-romem.txt
> 
> diff --git a/Documentation/devicetree/bindings/nvmem/st,stm32-romem.txt b/Documentation/devicetree/bindings/nvmem/st,stm32-romem.txt
> new file mode 100644
> index 0000000..fbff52e
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/nvmem/st,stm32-romem.txt
> @@ -0,0 +1,31 @@
> +STMicroelectronics STM32 Factory-programmed data device tree bindings
> +
> +This represents STM32 Factory-programmed read only non-volatile area: locked
> +flash, OTP, read-only HW regs... This contains various information such as:

Several distinct types here. Does s/w need to know the difference 
rather than just one generic-ish compatible? Access size restrictions 
maybe? Ability to unlock and program?

If not, then why even make this stm32 specific?

> +analog calibration data for temperature sensor (e.g. TS_CAL1, TS_CAL2),
> +internal vref (VREFIN_CAL), unique device ID...
> +
> +Required properties:
> +- compatible:		Should be one of:
> +			"st,stm32-romem"
> +			"st,stm32mp15-bsec"
> +- reg:			Offset and length of factory-programmed area.
> +- #address-cells:	Should be '<1>'.
> +- #size-cells:		Should be '<1>'.
> +
> +Optional Data cells:
> +- Must be child nodes as described in nvmem.txt.
> +
> +Example on stm32f4:
> +	romem: nvmem@1fff7800 {
> +		compatible = "st,stm32-romem";
> +		reg = <0x1fff7800 0x400>;
> +		#address-cells = <1>;
> +		#size-cells = <1>;
> +
> +		/* Data cells: ts_cal1 at 0x1fff7a2c */
> +		ts_cal1: calib@22c {
> +			reg = <0x22c 0x2>;
> +		};
> +		...
> +	};
> -- 
> 1.9.1
>