Boot process is halting in midway because some of the necessary voltage
regulators are deemed unused and subsequently powered off, leading to
a completely unresponsive system.
Most of the device nodes had correct voltage regulator attachments.
Yet these nodes had to set stricter enforcement on them through
'regulator-boot-on' and 'regulator-always-on' to function correctly.
The consumers of the regulators this commit affect are the followings:
DCDC1: vdd_1v8 system supply, USB-PHY, and ADC
DCDC2: Core domain
DCDC3: MPU core domain
LDO1: RTC
LDO2: 3v3 IO domain
LDO3: USB-PHY; not a boot-time requirement
LDO4: LCD [16:23]
All but LDO3 need to be always-on for the system to be functional.
Additionally regulator-name properties have been added for the kernel to
display the name from the schematic. This will improve diagnostics.
Signed-off-by: Adam YH Lee <adam.yh.lee@xxxxxxxxx>
---
arch/arm/boot/dts/am335x-pepper.dts | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/arch/arm/boot/dts/am335x-pepper.dts b/arch/arm/boot/dts/am335x-pepper.dts
index 0d35ab6..661f835 100644
--- a/arch/arm/boot/dts/am335x-pepper.dts
+++ b/arch/arm/boot/dts/am335x-pepper.dts
@@ -438,6 +438,7 @@
regulators {
dcdc1_reg: regulator@0 {
/* VDD_1V8 system supply */
+ regulator-always-on;
};
dcdc2_reg: regulator@1 {
@@ -446,6 +447,7 @@
regulator-min-microvolt = <925000>;
regulator-max-microvolt = <1325000>;
regulator-boot-on;
+ regulator-always-on;
};
dcdc3_reg: regulator@2 {
@@ -454,25 +456,32 @@
regulator-min-microvolt = <925000>;
regulator-max-microvolt = <1150000>;
regulator-boot-on;
+ regulator-always-on;
};
ldo1_reg: regulator@3 {
/* VRTC 1.8V always-on supply */
+ regulator-name = "vrtc,vdds";
regulator-always-on;
};
ldo2_reg: regulator@4 {
/* 3.3V rail */
+ regulator-name = "vdd_3v3aux";
+ regulator-always-on;
};
ldo3_reg: regulator@5 {
/* VDD_3V3A 3.3V rail */
+ regulator-name = "vdd_3v3a";
regulator-min-microvolt = <3300000>;
regulator-max-microvolt = <3300000>;
};
ldo4_reg: regulator@6 {
/* VDD_3V3B 3.3V rail */
+ regulator-name = "vdd_3v3b";
+ regulator-always-on;
};
};
};
--
2.1.4
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