[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@xxxxxx>
Acked-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
---

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