[PATCH V2] nvmem: add driver handling U-Boot environment variables

[Ahmad Fatoum]

Hello Rafał,

On 03.05.22 18:56, Rafał Miłecki wrote:
> From: Rafał Miłecki <rafal at milecki.pl>
> 
> U-Boot stores its setup as environment variables. It's a list of
> key-value pairs stored on flash device with a custom header.
> 
> This commit adds an NVMEM driver that:
> 1. Provides NVMEM access to environment vars binary data
> 2. Extracts variables as NVMEM cells
> 
> It can be used for:
> 1. Accessing env variables from user-space

Is this already possible? The only interface I know of is the /nvmem
file in sysfs, but that one is not per cell, but per device.

> +	label = of_get_property(np->parent, "label", NULL);
> +	if (!label)
> +		label = np->parent->name;
> +
> +	priv->mtd = get_mtd_device_nm(label);
> +	if (IS_ERR(priv->mtd)) {
> +		dev_err(dev, "Failed to find \"%s\" MTD device: %ld\n", label, PTR_ERR(priv->mtd));
> +		return PTR_ERR(priv->mtd);
> +	}

I am trying to make sense of this using the binding, but I can't.
Do you have an example device tree fragment?

Cheers,
Ahmad

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