From: E Shattow <e@freeshell.de>
To: Hung-Chun Tseng <alan.tseng.cs@gmail.com>,
Yixun Lan <dlan@kernel.org>, Rob Herring <robh@kernel.org>,
Krzysztof Kozlowski <krzk+dt@kernel.org>,
Conor Dooley <conor+dt@kernel.org>
Cc: Paul Walmsley <pjw@kernel.org>,
Palmer Dabbelt <palmer@dabbelt.com>,
Albert Ou <aou@eecs.berkeley.edu>,
Alexandre Ghiti <alex@ghiti.fr>,
devicetree@vger.kernel.org, linux-riscv@lists.infradead.org,
spacemit@lists.linux.dev, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 2/2] riscv: dts: spacemit: mark K1 board boot devices bootph-pre-ram
Date: Sat, 17 Oct 2026 14:44:21 -0700 [thread overview]
Message-ID: <13d6926f-f085-4214-8051-7bf7b5d92b67@freeshell.de> (raw)
In-Reply-To: <20261017180141.3477743-3-alan.tseng.cs@gmail.com>
Hi Hung-Chun,
On 10/17/26 11:01, Hung-Chun Tseng wrote:
> On K1 boards an SPL reads the board EEPROM (0x50 on i2c2) to identify
> the board, and before DRAM training it programs the P1 PMIC (0x41 on
> i2c8) rails buck1, buck3 and aldo1. Boards that boot from SPI NOR also
> need the flash on QSPI.
I think this statement is too much a description of software. It is not
interesting what the user-provided SPL does of some other software
project here for the hardware description in Linux device tree.
If the BootROM does this EEPROM configuration, then we could reasonably
extend bootph-pre-ram tags with the understanding that any SPL will need
those same interfaces. Does BootROM configure the EEPROM peripheral for
access? If not, I think the justification is weak here to include this.
Ask vendor-employed developer(s) to give us a flow chart of the BootROM
boot flows and list of configured peripherals in each boot flow. At a
minimum we should have those peripherals configured and refer to that
correspondance for justification. Additional to this we should identify
what is not configured by the BootROM.
>
> Mark these board peripherals bootph-pre-ram on the boards that have
> them, together with i2c2 where the EEPROM sits. i2c8 is tagged in
> k1.dtsi, as every K1 board connects the PMIC there.
>
> Assisted-by: claude-opus-5-5 dtbs_check
> Signed-off-by: Hung-Chun Tseng <alan.tseng.cs@gmail.com>
> ---
> arch/riscv/boot/dts/spacemit/k1-bananapi-cm6.dtsi | 6 ++++++
> arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts | 6 ++++++
> arch/riscv/boot/dts/spacemit/k1-milkv-jupiter.dts | 7 +++++++
> arch/riscv/boot/dts/spacemit/k1-musepi-pro.dts | 7 +++++++
> arch/riscv/boot/dts/spacemit/k1-orangepi-r2s.dts | 4 ++++
> arch/riscv/boot/dts/spacemit/k1-orangepi-rv2.dts | 5 +++++
> 6 files changed, 35 insertions(+)
>
> diff --git a/arch/riscv/boot/dts/spacemit/k1-bananapi-cm6.dtsi b/arch/riscv/boot/dts/spacemit/k1-bananapi-cm6.dtsi
> index 81c40df2a..acb8fa2e6 100644
> --- a/arch/riscv/boot/dts/spacemit/k1-bananapi-cm6.dtsi
> +++ b/arch/riscv/boot/dts/spacemit/k1-bananapi-cm6.dtsi
> @@ -64,6 +64,7 @@ &pdma {
> };
>
> &i2c2 {
> + bootph-pre-ram;
> pinctrl-names = "default";
> pinctrl-0 = <&i2c2_0_cfg>;
> status = "okay";
> @@ -71,6 +72,7 @@ &i2c2 {
> eeprom@50 {
> compatible = "atmel,24c02";
> reg = <0x50>;
> + bootph-pre-ram;
> vcc-supply = <&buck3_1v8>;
> pagesize = <16>;
> read-only;
> @@ -100,6 +102,7 @@ &i2c8 {
> pmic@41 {
> compatible = "spacemit,p1";
> reg = <0x41>;
> + bootph-pre-ram;
> interrupts = <64>;
> vin1-supply = <®_vcc_4v>;
> vin2-supply = <®_vcc_4v>;
> @@ -113,6 +116,7 @@ pmic@41 {
>
> regulators {
> buck1 {
> + bootph-pre-ram;
> regulator-min-microvolt = <500000>;
> regulator-max-microvolt = <1050000>;
> regulator-ramp-delay = <5000>;
> @@ -127,6 +131,7 @@ buck2 {
> };
>
> buck3_1v8: buck3 {
> + bootph-pre-ram;
> regulator-min-microvolt = <500000>;
> regulator-max-microvolt = <1800000>;
> regulator-ramp-delay = <5000>;
> @@ -155,6 +160,7 @@ buck6 {
> };
>
> aldo1: aldo1 {
> + bootph-pre-ram;
> regulator-min-microvolt = <500000>;
> regulator-max-microvolt = <3400000>;
> regulator-boot-on;
> diff --git a/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts b/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
> index 58035d886..b91db3204 100644
> --- a/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
> +++ b/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
> @@ -187,6 +187,7 @@ &qspi {
> };
>
> &i2c2 {
> + bootph-pre-ram;
> pinctrl-0 = <&i2c2_0_cfg>;
> pinctrl-names = "default";
> status = "okay";
> @@ -194,6 +195,7 @@ &i2c2 {
> eeprom@50 {
> compatible = "atmel,24c02";
> reg = <0x50>;
> + bootph-pre-ram;
> vcc-supply = <&buck3_1v8>; /* EEPROM_VCC1V8 */
> pagesize = <16>;
> read-only;
> @@ -223,6 +225,7 @@ &i2c8 {
> pmic@41 {
> compatible = "spacemit,p1";
> reg = <0x41>;
> + bootph-pre-ram;
> interrupts = <64>;
> vin1-supply = <®_vcc_4v>;
> vin2-supply = <®_vcc_4v>;
> @@ -236,6 +239,7 @@ pmic@41 {
>
> regulators {
> buck1_0v9: buck1 {
> + bootph-pre-ram;
> regulator-min-microvolt = <500000>;
> regulator-max-microvolt = <1050000>;
> regulator-ramp-delay = <5000>;
> @@ -250,6 +254,7 @@ buck2 {
> };
>
> buck3_1v8: buck3 {
> + bootph-pre-ram;
> regulator-min-microvolt = <500000>;
> regulator-max-microvolt = <1800000>;
> regulator-ramp-delay = <5000>;
> @@ -278,6 +283,7 @@ buck6 {
> };
>
> aldo1: aldo1 {
> + bootph-pre-ram;
> regulator-min-microvolt = <500000>;
> regulator-max-microvolt = <3400000>;
> regulator-boot-on;
> diff --git a/arch/riscv/boot/dts/spacemit/k1-milkv-jupiter.dts b/arch/riscv/boot/dts/spacemit/k1-milkv-jupiter.dts
> index 635e95aad..d2a39cf55 100644
> --- a/arch/riscv/boot/dts/spacemit/k1-milkv-jupiter.dts
> +++ b/arch/riscv/boot/dts/spacemit/k1-milkv-jupiter.dts
> @@ -201,6 +201,7 @@ &pdma {
> };
>
> &i2c2 {
> + bootph-pre-ram;
> pinctrl-0 = <&i2c2_0_cfg>;
> pinctrl-names = "default";
> status = "okay";
> @@ -208,6 +209,7 @@ &i2c2 {
> eeprom@50 {
> compatible = "atmel,24c04";
> reg = <0x50>;
> + bootph-pre-ram;
> vcc-supply = <&buck3_1v8>; /* EEPROM_VCC18 */
> pagesize = <16>;
> read-only;
> @@ -230,6 +232,7 @@ &i2c8 {
> pmic@41 {
> compatible = "spacemit,p1";
> reg = <0x41>;
> + bootph-pre-ram;
> interrupts = <64>;
> vin1-supply = <®_vcc_4v>;
> vin2-supply = <®_vcc_4v>;
> @@ -243,6 +246,7 @@ pmic@41 {
>
> regulators {
> buck1_0v9: buck1 {
> + bootph-pre-ram;
> regulator-min-microvolt = <500000>;
> regulator-max-microvolt = <1050000>;
> regulator-ramp-delay = <5000>;
> @@ -257,6 +261,7 @@ buck2 {
> };
>
> buck3_1v8: buck3 {
> + bootph-pre-ram;
> regulator-min-microvolt = <500000>;
> regulator-max-microvolt = <1800000>;
> regulator-ramp-delay = <5000>;
> @@ -285,6 +290,7 @@ buck6 {
> };
>
> aldo1: aldo1 {
> + bootph-pre-ram;
> regulator-min-microvolt = <500000>;
> regulator-max-microvolt = <3400000>;
> regulator-boot-on;
> @@ -386,6 +392,7 @@ &qspi {
> flash@0 {
> compatible = "jedec,spi-nor";
> reg = <0>;
> + bootph-pre-ram;
> spi-max-frequency = <26500000>;
> spi-rx-bus-width = <4>;
> spi-tx-bus-width = <4>;
> diff --git a/arch/riscv/boot/dts/spacemit/k1-musepi-pro.dts b/arch/riscv/boot/dts/spacemit/k1-musepi-pro.dts
> index 23f32a8a3..a3d0e38ac 100644
> --- a/arch/riscv/boot/dts/spacemit/k1-musepi-pro.dts
> +++ b/arch/riscv/boot/dts/spacemit/k1-musepi-pro.dts
> @@ -160,6 +160,7 @@ &pdma {
> };
>
> &i2c2 {
> + bootph-pre-ram;
> pinctrl-0 = <&i2c2_0_cfg>;
> pinctrl-names = "default";
> status = "okay";
> @@ -167,6 +168,7 @@ &i2c2 {
> eeprom@50 {
> compatible = "atmel,24c02";
> reg = <0x50>;
> + bootph-pre-ram;
> vcc-supply = <&buck3_1v8>; /* EEPROM_VCC1V8 */
> pagesize = <8>;
> read-only;
> @@ -199,6 +201,7 @@ &i2c8 {
> pmic@41 {
> compatible = "spacemit,p1";
> reg = <0x41>;
> + bootph-pre-ram;
> interrupts = <64>;
> vin1-supply = <®_vcc_4v>;
> vin2-supply = <®_vcc_4v>;
> @@ -212,6 +215,7 @@ pmic@41 {
>
> regulators {
> buck1_0v9: buck1 {
> + bootph-pre-ram;
> regulator-min-microvolt = <500000>;
> regulator-max-microvolt = <1050000>;
> regulator-ramp-delay = <5000>;
> @@ -226,6 +230,7 @@ buck2 {
> };
>
> buck3_1v8: buck3 {
> + bootph-pre-ram;
> regulator-min-microvolt = <500000>;
> regulator-max-microvolt = <1800000>;
> regulator-ramp-delay = <5000>;
> @@ -254,6 +259,7 @@ buck6 {
> };
>
> aldo1: aldo1 {
> + bootph-pre-ram;
> regulator-min-microvolt = <500000>;
> regulator-max-microvolt = <3400000>;
> regulator-boot-on;
> @@ -353,6 +359,7 @@ &qspi {
> flash@0 {
> compatible = "jedec,spi-nor";
> reg = <0>;
> + bootph-pre-ram;
> spi-max-frequency = <26500000>;
> spi-rx-bus-width = <4>;
> spi-tx-bus-width = <4>;
> diff --git a/arch/riscv/boot/dts/spacemit/k1-orangepi-r2s.dts b/arch/riscv/boot/dts/spacemit/k1-orangepi-r2s.dts
> index eb77aae9d..5e2fde8be 100644
> --- a/arch/riscv/boot/dts/spacemit/k1-orangepi-r2s.dts
> +++ b/arch/riscv/boot/dts/spacemit/k1-orangepi-r2s.dts
> @@ -187,6 +187,7 @@ &i2c8 {
> pmic@41 {
> compatible = "spacemit,p1";
> reg = <0x41>;
> + bootph-pre-ram;
> interrupts = <64>;
> vin1-supply = <&vcc4v0>;
> vin2-supply = <&vcc4v0>;
> @@ -200,6 +201,7 @@ pmic@41 {
>
> regulators {
> buck1_0v9: buck1 {
> + bootph-pre-ram;
> regulator-min-microvolt = <500000>;
> regulator-max-microvolt = <1050000>;
> regulator-ramp-delay = <5000>;
> @@ -214,6 +216,7 @@ buck2 {
> };
>
> buck3_1v8: buck3 {
> + bootph-pre-ram;
> regulator-min-microvolt = <500000>;
> regulator-max-microvolt = <1800000>;
> regulator-ramp-delay = <5000>;
> @@ -242,6 +245,7 @@ buck6 {
> };
>
> aldo1_3v3: aldo1 {
> + bootph-pre-ram;
> regulator-min-microvolt = <500000>;
> regulator-max-microvolt = <3400000>;
> regulator-boot-on;
> diff --git a/arch/riscv/boot/dts/spacemit/k1-orangepi-rv2.dts b/arch/riscv/boot/dts/spacemit/k1-orangepi-rv2.dts
> index 790234f35..d4adfc5b7 100644
> --- a/arch/riscv/boot/dts/spacemit/k1-orangepi-rv2.dts
> +++ b/arch/riscv/boot/dts/spacemit/k1-orangepi-rv2.dts
> @@ -214,6 +214,7 @@ &i2c8 {
> pmic@41 {
> compatible = "spacemit,p1";
> reg = <0x41>;
> + bootph-pre-ram;
> interrupts = <64>;
> vin1-supply = <&vcc4v0>;
> vin2-supply = <&vcc4v0>;
> @@ -227,6 +228,7 @@ pmic@41 {
>
> regulators {
> buck1_0v9: buck1 {
> + bootph-pre-ram;
> regulator-min-microvolt = <500000>;
> regulator-max-microvolt = <1050000>;
> regulator-ramp-delay = <5000>;
> @@ -241,6 +243,7 @@ buck2 {
> };
>
> buck3_1v8: buck3 {
> + bootph-pre-ram;
> regulator-min-microvolt = <500000>;
> regulator-max-microvolt = <1800000>;
> regulator-ramp-delay = <5000>;
> @@ -269,6 +272,7 @@ buck6 {
> };
>
> aldo1: aldo1 {
> + bootph-pre-ram;
> regulator-min-microvolt = <500000>;
> regulator-max-microvolt = <3400000>;
> regulator-boot-on;
> @@ -366,6 +370,7 @@ &qspi {
> flash@0 {
> compatible = "jedec,spi-nor";
> reg = <0>;
> + bootph-pre-ram;
> spi-max-frequency = <26500000>;
> spi-rx-bus-width = <4>;
> spi-tx-bus-width = <4>;
I do not agree with the "trust me, bro, I need this to boot" approach to
device tree upstream if it is at all avoidable. However it is difficult
to know without a listing of the BootROM.
With that, and having no visibility into the workings of BootROM myself,
the shape of this appears good. I'd like to see that discussion happen
about what BootROM is doing and more specifically what it is not doing
that we are amending for the benefit of software in this description of
hardware.
Reviewed-by: E Shattow <e@freeshell.de>
prev parent reply other threads:[~2026-10-17 21:44 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-17 18:01 [PATCH v2 0/2] riscv: dts: spacemit: mark K1 boot nodes bootph-pre-ram Hung-Chun Tseng
2026-10-17 18:01 ` [PATCH v2 1/2] riscv: dts: spacemit: k1: mark boot-critical SoC " Hung-Chun Tseng
2026-10-17 21:05 ` E Shattow
2026-10-18 14:08 ` Hung-Chun Tseng
2026-10-17 18:01 ` [PATCH v2 2/2] riscv: dts: spacemit: mark K1 board boot devices bootph-pre-ram Hung-Chun Tseng
2026-10-17 21:44 ` E Shattow [this message]
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