[PATCH v4] arm64: dts: ti: k3-am65: Add support for UHS-I modes in MMCSD1 subsystem

[PATCH v4] arm64: dts: ti: k3-am65: Add support for UHS-I modes in MMCSD1 subsystem

[Aswath Govindraju]

UHS-I speed modes are supported in AM65 S.R. 2.0 SoC[1].

Add support by removing the no-1-8-v tag and including the voltage
regulator device tree nodes for power cycling.

However, the 4 bit interface of AM65 SR 1.0 cannot be supported at 3.3 V or
1.8 V because of erratas i2025 and i2026 [2]. As the SD card is the primary
boot mode for development usecases, continue to enable SD card and disable
UHS-I modes in it to minimize any ageing issues happening because of
erratas.

k3-am6528-iot2050-basic and k3-am6548-iot2050-advanced boards use S.R. 1.0
version of AM65 SoC. Therefore, add no-1-8-v in sdhci1 device tree node of
the common iot2050 device tree file.

[1] - https://www.ti.com/lit/ug/spruid7e/spruid7e.pdf, section 12.3.6.1.1
[2] - https://www.ti.com/lit/er/sprz452e/sprz452e.pdf

Signed-off-by: Aswath Govindraju <a-govindraju@ti.com>
Acked-by: Jan Kiszka <jan.kiszka@siemens.com>
---

KPV test report:
- https://pastebin.ubuntu.com/p/wnQQTrJZP6/

changes since v3:
- rebased on top of https://git.kernel.org/pub/scm/linux/kernel/git/nmenon/linux.git/log/?h=ti-k3-dts-next
- Picked up Jan's ack

changes since v2:
- moved the no-1-8-v tag to common iot2050 dtsi file.

changes since v1:
- added no-1-8-v tag in sdhci1 dt nodes of k3-am6528-iot2050-basic and
  k3-am6548-iot2050-advanced boards as they use S.R.1.0 version AM65 SoC.

 .../boot/dts/ti/k3-am65-iot2050-common.dtsi   |  1 +
 arch/arm64/boot/dts/ti/k3-am65-main.dtsi      |  1 -
 .../arm64/boot/dts/ti/k3-am654-base-board.dts | 33 +++++++++++++++++++
 3 files changed, 34 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/ti/k3-am65-iot2050-common.dtsi b/arch/arm64/boot/dts/ti/k3-am65-iot2050-common.dtsi
index f4ec9ed52939..d90abda1de84 100644
--- a/arch/arm64/boot/dts/ti/k3-am65-iot2050-common.dtsi
+++ b/arch/arm64/boot/dts/ti/k3-am65-iot2050-common.dtsi
@@ -555,6 +555,7 @@
 	pinctrl-0 = <&main_mmc1_pins_default>;
 	ti,driver-strength-ohm = <50>;
 	disable-wp;
+	no-1-8-v;
 };
 
 &usb0 {
diff --git a/arch/arm64/boot/dts/ti/k3-am65-main.dtsi b/arch/arm64/boot/dts/ti/k3-am65-main.dtsi
index 6cd3131eb9ff..f97fc00c00ca 100644
--- a/arch/arm64/boot/dts/ti/k3-am65-main.dtsi
+++ b/arch/arm64/boot/dts/ti/k3-am65-main.dtsi
@@ -301,7 +301,6 @@
 		ti,otap-del-sel = <0x2>;
 		ti,trm-icp = <0x8>;
 		dma-coherent;
-		no-1-8-v;
 	};
 
 	scm_conf: scm-conf@100000 {
diff --git a/arch/arm64/boot/dts/ti/k3-am654-base-board.dts b/arch/arm64/boot/dts/ti/k3-am654-base-board.dts
index 97c344088483..60e43fd7af12 100644
--- a/arch/arm64/boot/dts/ti/k3-am654-base-board.dts
+++ b/arch/arm64/boot/dts/ti/k3-am654-base-board.dts
@@ -85,6 +85,38 @@
 			gpios = <&wkup_gpio0 27 GPIO_ACTIVE_LOW>;
 		};
 	};
+
+	evm_12v0: fixedregulator-evm12v0 {
+		/* main supply */
+		compatible = "regulator-fixed";
+		regulator-name = "evm_12v0";
+		regulator-min-microvolt = <12000000>;
+		regulator-max-microvolt = <12000000>;
+		regulator-always-on;
+		regulator-boot-on;
+	};
+
+	vcc3v3_io: fixedregulator-vcc3v3io {
+		/* Output of TPS54334 */
+		compatible = "regulator-fixed";
+		regulator-name = "vcc3v3_io";
+		regulator-min-microvolt = <3300000>;
+		regulator-max-microvolt = <3300000>;
+		regulator-always-on;
+		regulator-boot-on;
+		vin-supply = <&evm_12v0>;
+	};
+
+	vdd_mmc1_sd: fixedregulator-sd {
+		compatible = "regulator-fixed";
+		regulator-name = "vdd_mmc1_sd";
+		regulator-min-microvolt = <3300000>;
+		regulator-max-microvolt = <3300000>;
+		regulator-boot-on;
+		enable-active-high;
+		vin-supply = <&vcc3v3_io>;
+		gpio = <&pca9554 4 GPIO_ACTIVE_HIGH>;
+	};
 };
 
 &wkup_pmx0 {
@@ -327,6 +359,7 @@
  * disable sdhci1
  */
 &sdhci1 {
+	vmmc-supply = <&vdd_mmc1_sd>;
 	pinctrl-names = "default";
 	pinctrl-0 = <&main_mmc1_pins_default>;
 	ti,driver-strength-ohm = <50>;
-- 
2.17.1

Re: [PATCH v4] arm64: dts: ti: k3-am65: Add support for UHS-I modes in MMCSD1 subsystem

[Nishanth Menon]

On Sat, 29 May 2021 09:07:49 +0530, Aswath Govindraju wrote:
> UHS-I speed modes are supported in AM65 S.R. 2.0 SoC[1].
> 
> Add support by removing the no-1-8-v tag and including the voltage
> regulator device tree nodes for power cycling.
> 
> However, the 4 bit interface of AM65 SR 1.0 cannot be supported at 3.3 V or
> 1.8 V because of erratas i2025 and i2026 [2]. As the SD card is the primary
> boot mode for development usecases, continue to enable SD card and disable
> UHS-I modes in it to minimize any ageing issues happening because of
> erratas.
> 
> [...]

Hi Aswath Govindraju,

I have applied the following to branch ti-k3-dts-next on [1].
Thank you!

[1/1] arm64: dts: ti: k3-am65: Add support for UHS-I modes in MMCSD1 subsystem
      commit: 79b08ae7c411840ea5a9fba349025d217e700576


All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent up the chain during
the next merge window (or sooner if it is a relevant bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

[1] git://git.kernel.org/pub/scm/linux/kernel/git/nmenon/linux.git
-- 
Regards,
Nishanth Menon
Key (0xDDB5849D1736249D) / Fingerprint: F8A2 8693 54EB 8232 17A3  1A34 DDB5 849D 1736 249D