Re: [Linux-stm32] [PATCH V4] nvmem: add explicit config option to read old syntax fixed OF cells

From: "Rafał Miłecki" <rafal@milecki.pl>
To: Ahmad Fatoum <a.fatoum@pengutronix.de>
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Subject: Re: [Linux-stm32] [PATCH V4] nvmem: add explicit config option to read old syntax fixed OF cells
Date: Tue, 18 Jul 2023 11:19:49 +0200	[thread overview]
Message-ID: <d51234ebc05d2b9fe44625299c103caa@milecki.pl> (raw)
In-Reply-To: <e5a8524c-8961-9ff0-db30-3b648345319e@pengutronix.de>

Hi Ahmad,

On 2023-07-18 11:08, Ahmad Fatoum wrote:
>> diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
>> index 60670b2f70b9..334adbae3690 100644
>> --- a/drivers/mtd/mtdcore.c
>> +++ b/drivers/mtd/mtdcore.c
>> @@ -522,6 +522,7 @@ static int mtd_nvmem_add(struct mtd_info *mtd)
>>  	config.dev = &mtd->dev;
>>  	config.name = dev_name(&mtd->dev);
>>  	config.owner = THIS_MODULE;
>> +	config.add_legacy_fixed_of_cells = of_device_is_compatible(node, 
>> "nvmem-cells");
> 
> How does the new binding look like in this situation?
> 
> Before it was:
> 
> &{flash/partitions} {
> 	compatible = "fixed-partitions";
> 	#address-cells = <1>;
> 	#size-cells = <1>;
> 
> 	partition@0 {
> 		compatible = "nvmem-cells";
> 		reg = <0 0x100>;
> 		#address-cells = <1>;
> 		#size-cells = <1>;
> 
> 		calib@1 {
> 			reg = <1 1>;
> 		};
> 	}
> };
> 
> It it now the same, but s/"nvmem-cells"/"fixed-layout"/ ?

Please take a look at those commits and examples:

bd912c991d2e ("dt-bindings: nvmem: layouts: add fixed-layout")
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=bd912c991d2ef079a32558f057b8663bcf1fb6fc

fa7fbe53ecdc ("dt-bindings: nvmem: convert base example to use NVMEM 
fixed cells layout")
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=fa7fbe53ecdc4e7d549a9f73a40e257b0046b4b9

Basically you need a "nvmem-layout" node with:
compatible = "fixed-layout";

So in your case that would be:

&{flash/partitions} {
	compatible = "fixed-partitions";

	partition@0 {
		reg = <0 0x100>;

		nvmem-layout {
			compatible = "fixed-layout";
			#address-cells = <1>;
			#size-cells = <1>;

			calib@1 {
				reg = <1 1>;
			};
		};
	}
};