Tool/software:
We are migrating a design from SDK 6 (Linux v4.10) to SDK 9. We didn't have any major issues so far, but when I enable the UART 6 in the DTB the kernel fails to load. It gets stuck on "Starting kernel ..." message in U-Boot.
If I set the uart6 status to "disabled", then it boots.
I am using the U-Boot from SDK 6 and booting via TFTP. I know the HW and the Pinmux are OK because booting with SDK 6 kernel works, and U-Boot sets the pinmux. My console UART is UART1, so I should be seeing the boot messages.
I suspect something is broken in the clocking, because UART6 uses CD_IPU and the other UARTs I use are on CD_L4_PER1. However, I don't undertand why it fails to enable such clock.
Any suggestion on how to debug this? It's hard because as soon as I enable the UART, I no longer see anything so printk()-based debug is not an option.
This is the DTS I am using, the kernel is compiled with no modifications on the default SDK:
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2016 Texas Instruments Incorporated - https://www.ti.com/
*/
#include "dra71x.dtsi"
#include "dra7-mmc-iodelay.dtsi"
#include "dra72x-mmc-iodelay.dtsi"
#include "am5718.dtsi"
#include "dra7-ipu-dsp-common.dtsi"
#include <dt-bindings/gpio/gpio.h>
/ {
compatible = "ti,dra718-evm", "ti,dra718", "ti,dra722", "ti,dra72", "ti,dra7";
model = "TI DRA718 EVM";
memory {
device_type = "memory";
reg = <0x0 0x80000000 0x0 0x40000000>; /* 1GB */
};
reserved-memory {
#address-cells = <2>;
#size-cells = <2>;
ranges;
ipu2_memory_region: ipu2-memory@95800000 {
compatible = "shared-dma-pool";
reg = <0x0 0x95800000 0x0 0x3800000>;
reusable;
status = "okay";
};
dsp1_memory_region: dsp1-memory@99000000 {
compatible = "shared-dma-pool";
reg = <0x0 0x99000000 0x0 0x4000000>;
reusable;
status = "okay";
};
ipu1_memory_region: ipu1-memory@9d000000 {
compatible = "shared-dma-pool";
reg = <0x0 0x9d000000 0x0 0x2000000>;
reusable;
status = "okay";
};
};
vpo_sd_1v8_3v3: gpio-regulator-TPS74801 {
compatible = "regulator-gpio";
regulator-name = "vddshv8";
regulator-okmin-microvolt = <1800000>;
regulator-max-microvolt = <3000000>;
regulator-boot-on;
vin-supply = <&evm_5v0>;
gpios = <&gpio7 11 GPIO_ACTIVE_HIGH>;
states = <1800000 0x0
3000000 0x1>;
};
evm_1v8_sw: fixedregulator-evm_1v8 {
compatible = "regulator-fixed";
regulator-name = "evm_1v8";
regulator-min-microvolt = <1800000>;
regulator-max-microvolt = <1800000>;
vin-supply = <&lp8732_buck0_reg>;
regulator-always-on;
regulator-boot-on;
};
poweroff: gpio-poweroff {
compatible = "gpio-poweroff";
gpios = <&gpio7 30 GPIO_ACTIVE_HIGH>;
input;
};
reserved-memory {
#address-cells = <2>;
#size-cells = <2>;
ranges;
/* CMEM For di-platform FW (dsp1, ipu1 and A15) */
cmem_block_mem_0: cmem_block_mem@93000000 {
reg = <0x0 0x93000000 0x0 0x2000000>;
no-map;
status = "okay";
};
/* CMEM for Bridge PRUSS1 ADC */
pru1-memory@9fec0000 {
reg = <0x0 0x950c0000 0x0 0x40000>;
no-map;
status = "okay";
};
};
cmem {
compatible = "ti,cmem";
#address-cells = <1>;
#size-cells = <0>;
#pool-size-cells = <2>;
status = "okay";
cmem_block_0: cmem_block@0 {
reg = <0>;
memory-region = <&cmem_block_mem_0>;
cmem-buf-pools = <0x1 0x0 0x2000000>;
};
};
};
&i2c1 {
status = "okay";
clock-frequency = <400000>;
lp8733: lp8733@60 {
compatible = "ti,lp8733";
reg = <0x60>;
buck0-in-supply =<&vsys_3v3>;
buck1-in-supply =<&vsys_3v3>;
ldo0-in-supply =<&evm_5v0>;
ldo1-in-supply =<&evm_5v0>;
lp8733_regulators: regulators {
lp8733_buck0_reg: buck0 {
/* FB_B0 -> LP8733-BUCK1 - VPO_S1_AVS - VDD_CORE_AVS (core, mpu, gpu) */
regulator-name = "lp8733-buck0";
regulator-min-microvolt = <850000>;
regulator-max-microvolt = <1250000>;
regulator-always-on;
regulator-boot-on;
};
lp8733_buck1_reg: buck1 {
/* FB_B1 -> LP8733-BUCK2 - VPO_S2_AVS - VDD_DSP_AVS (DSP/eve/iva) */
regulator-name = "lp8733-buck1";
regulator-min-microvolt = <850000>;
regulator-max-microvolt = <1250000>;
regulator-boot-on;
regulator-always-on;
};
lp8733_ldo0_reg: ldo0 {
/* LDO0 -> LP8733-LDO1 - VPO_L1_3V3 - VDDSHV8 (optional) */
regulator-name = "lp8733-ldo0";
regulator-min-microvolt = <3300000>;
regulator-max-microvolt = <3300000>;
regulator-boot-on;
regulator-always-on;
};
lp8733_ldo1_reg: ldo1 {
/* LDO1 -> LP8733-LDO2 - VPO_L2_3V3 - VDDA_USB3V3 */
regulator-name = "lp8733-ldo1";
regulator-min-microvolt = <3300000>;
regulator-max-microvolt = <3300000>;
regulator-always-on;
regulator-boot-on;
};
};
};
lp8732: lp8732@61 {
compatible = "ti,lp8732";
reg = <0x61>;
buck0-in-supply =<&vsys_3v3>;
buck1-in-supply =<&vsys_3v3>;
ldo0-in-supply =<&vsys_3v3>;
ldo1-in-supply =<&vsys_3v3>;
lp8732_regulators: regulators {
lp8732_buck0_reg: buck0 {
/* FB_B0 -> LP8732-BUCK1 - VPO_S3_1V8 - VDDS_1V8 */
regulator-name = "lp8732-buck0";
regulator-min-microvolt = <1800000>;
regulator-max-microvolt = <1800000>;
regulator-always-on;
regulator-boot-on;
};
lp8732_buck1_reg: buck1 {
/* FB_B1 -> LP8732-BUCK2 - VPO_S4_DDR - VDD_DDR_1V35 */
regulator-name = "lp8732-buck1";
regulator-min-microvolt = <1350000>;
regulator-max-microvolt = <1350000>;
regulator-boot-on;
regulator-always-on;
};
lp8732_ldo0_reg: ldo0 {
/* LDO0 -> LP8732-LDO1 - VPO_L3_1V8 - VDA_1V8_PLL */
regulator-name = "lp8732-ldo0";
regulator-min-microvolt = <1800000>;
regulator-max-microvolt = <1800000>;
regulator-boot-on;
regulator-always-on;
};
lp8732_ldo1_reg: ldo1 {
/* LDO1 -> LP8732-LDO2 - VPO_L4_1V8 - VDA_1V8_PHY */
regulator-name = "lp8732-ldo1";
regulator-min-microvolt = <1800000>;
regulator-max-microvolt = <1800000>;
regulator-always-on;
regulator-boot-on;
};
};
};
};
&uart1 {
status = "okay";
overrun-throttle-ms = <500>;
};
&uart3 {
status = "okay";
overrun-throttle-ms = <500>;
};
#if 1
/* FIXME: doesn't boot, probably needs a clock? */
&uart6 {
status = "okay";
//overrun-throttle-ms = <500>;
};
#endif
