[PATCH 3/5] arm64: dts: imx8m: Document the fuse address calculation

[Peng Fan]

> Subject: [PATCH 3/5] arm64: dts: imx8m: Document the fuse address
> calculation
> 
> The mapping from OCOTP reg DT property to Fusemap Descriptions Table in
> the datasheet is often unclear. Add a comment to make it easier to find out
> how it works. No functional change.
> 
> Signed-off-by: Marek Vasut <marex at denx.de>

Reviewed-by: Peng Fan <peng.fan at nxp.com>
> ---
> Cc: Adam Ford <aford173 at gmail.com>
> Cc: Alice Guo <alice.guo at nxp.com>
> Cc: Amit Kucheria <amitk at kernel.org>
> Cc: Daniel Lezcano <daniel.lezcano at linaro.org>
> Cc: Fabio Estevam <festevam at gmail.com>
> Cc: Krzysztof Kozlowski <krzysztof.kozlowski+dt at linaro.org>
> Cc: Li Jun <jun.li at nxp.com>
> Cc: Lucas Stach <l.stach at pengutronix.de>
> Cc: Markus Niebel <Markus.Niebel at ew.tq-group.com>
> Cc: NXP Linux Team <linux-imx at nxp.com>
> Cc: Peng Fan <peng.fan at nxp.com>
> Cc: Pengutronix Kernel Team <kernel at pengutronix.de>
> Cc: Rafael J. Wysocki <rafael at kernel.org>
> Cc: Richard Cochran <richardcochran at gmail.com>
> Cc: Rob Herring <robh+dt at kernel.org>
> Cc: Sascha Hauer <s.hauer at pengutronix.de>
> Cc: Shawn Guo <shawnguo at kernel.org>
> Cc: Zhang Rui <rui.zhang at intel.com>
> Cc: devicetree at vger.kernel.org
> To: linux-pm at vger.kernel.org
> To: linux-arm-kernel at lists.infradead.org
> ---
>  arch/arm64/boot/dts/freescale/imx8mm.dtsi | 19 ++++++++++++++++---
> arch/arm64/boot/dts/freescale/imx8mn.dtsi | 19 ++++++++++++++++---
> arch/arm64/boot/dts/freescale/imx8mp.dtsi | 21 +++++++++++++++++----
> arch/arm64/boot/dts/freescale/imx8mq.dtsi | 19 ++++++++++++++++---
>  4 files changed, 65 insertions(+), 13 deletions(-)
> 
> diff --git a/arch/arm64/boot/dts/freescale/imx8mm.dtsi
> b/arch/arm64/boot/dts/freescale/imx8mm.dtsi
> index 423cb36cbcd53..513c2de0caa15 100644
> --- a/arch/arm64/boot/dts/freescale/imx8mm.dtsi
> +++ b/arch/arm64/boot/dts/freescale/imx8mm.dtsi
> @@ -563,15 +563,28 @@ ocotp: efuse at 30350000 {
>  				#address-cells = <1>;
>  				#size-cells = <1>;
> 
> -				imx8mm_uid: unique-id at 4 {
> +				/*
> +				 * The register address below maps to the
> MX8M
> +				 * Fusemap Description Table entries this way.
> +				 * Assuming
> +				 *   reg = <ADDR SIZE>;
> +				 * then
> +				 *   Fuse Address = (ADDR * 4) + 0x400
> +				 * Note that if SIZE is greater than 4, then
> +				 * each subsequent fuse is located at offset
> +				 * +0x10 in Fusemap Description Table (e.g.
> +				 * reg = <0x4 0x8> describes fuses 0x410 and
> +				 * 0x420).
> +				 */
> +				imx8mm_uid: unique-id at 4 { /* 0x410-0x420
> */
>  					reg = <0x4 0x8>;
>  				};
> 
> -				cpu_speed_grade: speed-grade at 10 {
> +				cpu_speed_grade: speed-grade at 10 { /*
> 0x440 */
>  					reg = <0x10 4>;
>  				};
> 
> -				fec_mac_address: mac-address at 90 {
> +				fec_mac_address: mac-address at 90 { /*
> 0x640 */
>  					reg = <0x90 6>;
>  				};
>  			};
> diff --git a/arch/arm64/boot/dts/freescale/imx8mn.dtsi
> b/arch/arm64/boot/dts/freescale/imx8mn.dtsi
> index 312e3abc35ea8..068f599cdf757 100644
> --- a/arch/arm64/boot/dts/freescale/imx8mn.dtsi
> +++ b/arch/arm64/boot/dts/freescale/imx8mn.dtsi
> @@ -564,15 +564,28 @@ ocotp: efuse at 30350000 {
>  				#address-cells = <1>;
>  				#size-cells = <1>;
> 
> -				imx8mn_uid: unique-id at 4 {
> +				/*
> +				 * The register address below maps to the
> MX8M
> +				 * Fusemap Description Table entries this way.
> +				 * Assuming
> +				 *   reg = <ADDR SIZE>;
> +				 * then
> +				 *   Fuse Address = (ADDR * 4) + 0x400
> +				 * Note that if SIZE is greater than 4, then
> +				 * each subsequent fuse is located at offset
> +				 * +0x10 in Fusemap Description Table (e.g.
> +				 * reg = <0x4 0x8> describes fuses 0x410 and
> +				 * 0x420).
> +				 */
> +				imx8mn_uid: unique-id at 4 { /* 0x410-0x420 */
>  					reg = <0x4 0x8>;
>  				};
> 
> -				cpu_speed_grade: speed-grade at 10 {
> +				cpu_speed_grade: speed-grade at 10 { /*
> 0x440 */
>  					reg = <0x10 4>;
>  				};
> 
> -				fec_mac_address: mac-address at 90 {
> +				fec_mac_address: mac-address at 90 { /*
> 0x640 */
>  					reg = <0x90 6>;
>  				};
>  			};
> diff --git a/arch/arm64/boot/dts/freescale/imx8mp.dtsi
> b/arch/arm64/boot/dts/freescale/imx8mp.dtsi
> index c9459ed21b243..ddcd5e23ba47d 100644
> --- a/arch/arm64/boot/dts/freescale/imx8mp.dtsi
> +++ b/arch/arm64/boot/dts/freescale/imx8mp.dtsi
> @@ -426,19 +426,32 @@ ocotp: efuse at 30350000 {
>  				#address-cells = <1>;
>  				#size-cells = <1>;
> 
> -				imx8mp_uid: unique-id at 8 {
> +				/*
> +				 * The register address below maps to the
> MX8M
> +				 * Fusemap Description Table entries this way.
> +				 * Assuming
> +				 *   reg = <ADDR SIZE>;
> +				 * then
> +				 *   Fuse Address = (ADDR * 4) + 0x400
> +				 * Note that if SIZE is greater than 4, then
> +				 * each subsequent fuse is located at offset
> +				 * +0x10 in Fusemap Description Table (e.g.
> +				 * reg = <0x8 0x8> describes fuses 0x420 and
> +				 * 0x430).
> +				 */
> +				imx8mp_uid: unique-id at 8 { /* 0x420-0x430 */
>  					reg = <0x8 0x8>;
>  				};
> 
> -				cpu_speed_grade: speed-grade at 10 {
> +				cpu_speed_grade: speed-grade at 10 { /*
> 0x440 */
>  					reg = <0x10 4>;
>  				};
> 
> -				eth_mac1: mac-address at 90 {
> +				eth_mac1: mac-address at 90 { /* 0x640 */
>  					reg = <0x90 6>;
>  				};
> 
> -				eth_mac2: mac-address at 96 {
> +				eth_mac2: mac-address at 96 { /* 0x658 */
>  					reg = <0x96 6>;
>  				};
>  			};
> diff --git a/arch/arm64/boot/dts/freescale/imx8mq.dtsi
> b/arch/arm64/boot/dts/freescale/imx8mq.dtsi
> index 2b6d3f4ff5d93..8a2ec90b493d9 100644
> --- a/arch/arm64/boot/dts/freescale/imx8mq.dtsi
> +++ b/arch/arm64/boot/dts/freescale/imx8mq.dtsi
> @@ -593,15 +593,28 @@ ocotp: efuse at 30350000 {
>  				#address-cells = <1>;
>  				#size-cells = <1>;
> 
> -				imx8mq_uid: soc-uid at 4 {
> +				/*
> +				 * The register address below maps to the
> MX8M
> +				 * Fusemap Description Table entries this way.
> +				 * Assuming
> +				 *   reg = <ADDR SIZE>;
> +				 * then
> +				 *   Fuse Address = (ADDR * 4) + 0x400
> +				 * Note that if SIZE is greater than 4, then
> +				 * each subsequent fuse is located at offset
> +				 * +0x10 in Fusemap Description Table (e.g.
> +				 * reg = <0x4 0x8> describes fuses 0x410 and
> +				 * 0x420).
> +				 */
> +				imx8mq_uid: soc-uid at 4 { /* 0x410-0x420 */
>  					reg = <0x4 0x8>;
>  				};
> 
> -				cpu_speed_grade: speed-grade at 10 {
> +				cpu_speed_grade: speed-grade at 10 { /*
> 0x440 */
>  					reg = <0x10 4>;
>  				};
> 
> -				fec_mac_address: mac-address at 90 {
> +				fec_mac_address: mac-address at 90 { /*
> 0x640 */
>  					reg = <0x90 6>;
>  				};
>  			};
> --
> 2.35.1