From: Michael Walle <michael@walle.cc> To: Rob Herring <robh@kernel.org> Cc: linux-mtd@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Miquel Raynal <miquel.raynal@bootlin.com>, Richard Weinberger <richard@nod.at>, Vignesh Raghavendra <vigneshr@ti.com>, Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Subject: Re: [PATCH 0/5] mtd: core: OTP nvmem provider support Date: Fri, 16 Apr 2021 21:26:03 +0200 [thread overview] Message-ID: <9f33229a8fe83b49210289fc93a8554e@walle.cc> (raw) In-Reply-To: <20210416184423.GA3715339@robh.at.kernel.org> Hi Rob, Am 2021-04-16 20:44, schrieb Rob Herring: > On Fri, Apr 16, 2021 at 01:49:23PM +0200, Michael Walle wrote: >> The goal is to fetch a (base) MAC address from the OTP region of a SPI >> NOR >> flash. >> >> This is the first part, where I try to add the nvmem provider support >> to >> the MTD core. >> >> I'm not sure about the device tree bindings. Consider the following >> two >> variants: >> >> (1) >> flash@0 { >> .. >> >> otp { >> compatible = "mtd-user-otp"; > > mtd is a linuxism. Why not just 'nvmem-cells' here or as a fallback if > we come up with a better name? There are two different compatibles: "mtd-user-otp" and "mtd-factory-otp" to differentiate what kind of OTP should be used (and both are possible at the same time). Thus nvmem-cells alone won't be enough. We could drop the "mtd-" prefix though. Is there a benefit of having the following? compatible = "user-otp", "nvmem-cells"; >> #address-cells = <1>; >> #size-cells = <1>; >> >> serial-number@0 { >> reg = <0x0 0x8>; >> }; >> }; >> }; >> >> (2) >> flash@0 { >> .. >> >> otp { >> compatible = "mtd-user-otp"; >> #address-cells = <1>; >> #size-cells = <1>; >> >> some-useful-name { >> compatible = "nvmem-cells"; >> >> serial-number@0 { >> reg = <0x0 0x8>; >> }; >> }; >> }; >> }; >> >> Both bindings use a subnode "opt[-N]". We cannot have the nvmem cells >> as >> children to the flash node because of the legacy partition binding. >> >> (1) seems to be the form which is used almost everywhere in the >> kernel. >> That is, the nvmem cells are just children of the parent node. >> >> (2) seem to be more natural, because there might also be other >> properties >> inside the otp subnode and might be more future-proof. >> >> At the moment this patch implements (1). > > I think approach (1) seems fine. ok -michael
WARNING: multiple messages have this Message-ID (diff)
From: Michael Walle <michael@walle.cc> To: Rob Herring <robh@kernel.org> Cc: linux-mtd@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Miquel Raynal <miquel.raynal@bootlin.com>, Richard Weinberger <richard@nod.at>, Vignesh Raghavendra <vigneshr@ti.com>, Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Subject: Re: [PATCH 0/5] mtd: core: OTP nvmem provider support Date: Fri, 16 Apr 2021 21:26:03 +0200 [thread overview] Message-ID: <9f33229a8fe83b49210289fc93a8554e@walle.cc> (raw) In-Reply-To: <20210416184423.GA3715339@robh.at.kernel.org> Hi Rob, Am 2021-04-16 20:44, schrieb Rob Herring: > On Fri, Apr 16, 2021 at 01:49:23PM +0200, Michael Walle wrote: >> The goal is to fetch a (base) MAC address from the OTP region of a SPI >> NOR >> flash. >> >> This is the first part, where I try to add the nvmem provider support >> to >> the MTD core. >> >> I'm not sure about the device tree bindings. Consider the following >> two >> variants: >> >> (1) >> flash@0 { >> .. >> >> otp { >> compatible = "mtd-user-otp"; > > mtd is a linuxism. Why not just 'nvmem-cells' here or as a fallback if > we come up with a better name? There are two different compatibles: "mtd-user-otp" and "mtd-factory-otp" to differentiate what kind of OTP should be used (and both are possible at the same time). Thus nvmem-cells alone won't be enough. We could drop the "mtd-" prefix though. Is there a benefit of having the following? compatible = "user-otp", "nvmem-cells"; >> #address-cells = <1>; >> #size-cells = <1>; >> >> serial-number@0 { >> reg = <0x0 0x8>; >> }; >> }; >> }; >> >> (2) >> flash@0 { >> .. >> >> otp { >> compatible = "mtd-user-otp"; >> #address-cells = <1>; >> #size-cells = <1>; >> >> some-useful-name { >> compatible = "nvmem-cells"; >> >> serial-number@0 { >> reg = <0x0 0x8>; >> }; >> }; >> }; >> }; >> >> Both bindings use a subnode "opt[-N]". We cannot have the nvmem cells >> as >> children to the flash node because of the legacy partition binding. >> >> (1) seems to be the form which is used almost everywhere in the >> kernel. >> That is, the nvmem cells are just children of the parent node. >> >> (2) seem to be more natural, because there might also be other >> properties >> inside the otp subnode and might be more future-proof. >> >> At the moment this patch implements (1). > > I think approach (1) seems fine. ok -michael ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/
next prev parent reply other threads:[~2021-04-16 19:26 UTC|newest] Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-04-16 11:49 [PATCH 0/5] mtd: core: OTP nvmem provider support Michael Walle 2021-04-16 11:49 ` Michael Walle 2021-04-16 11:49 ` [PATCH 1/5] nvmem: core: allow specifying of_node Michael Walle 2021-04-16 11:49 ` Michael Walle 2021-04-16 11:49 ` [PATCH 2/5] dt-bindings: mtd: add YAML schema for the generic MTD bindings Michael Walle 2021-04-16 11:49 ` Michael Walle 2021-04-16 11:49 ` [PATCH 3/5] dt-bindings: mtd: add OTP bindings Michael Walle 2021-04-16 11:49 ` Michael Walle 2021-04-16 18:30 ` Rob Herring 2021-04-16 18:30 ` Rob Herring 2021-04-16 18:46 ` Rob Herring 2021-04-16 18:46 ` Rob Herring 2021-04-16 11:49 ` [PATCH 4/5] dt-bindings: mtd: spi-nor: add otp property Michael Walle 2021-04-16 11:49 ` Michael Walle 2021-04-16 18:30 ` Rob Herring 2021-04-16 18:30 ` Rob Herring 2021-04-16 11:49 ` [PATCH 5/5] mtd: core: add OTP nvmem provider support Michael Walle 2021-04-16 11:49 ` Michael Walle 2021-04-16 18:44 ` [PATCH 0/5] mtd: core: " Rob Herring 2021-04-16 18:44 ` Rob Herring 2021-04-16 19:26 ` Michael Walle [this message] 2021-04-16 19:26 ` Michael Walle 2021-04-20 14:08 ` Rob Herring 2021-04-20 14:08 ` Rob Herring 2021-04-20 15:03 ` Michael Walle 2021-04-20 15:03 ` Michael Walle
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