CL-SOM-AM57x: Linux: Debian
Contents
- 1 Overview
- 2 Using Debian Linux on CL-SOM-AM57x
- 3 See also
Overview
The example run-time Linux filesystem image for the CompuLab CL-SOM-AM57x System-on-Module / Computer-on-Module is based on Debian GNU/Linux stretch/sid (armhf).
The default Debian sid Linux image includes many software packages. Among them:
- Core system
- Debian package management system
- X11 Windowing System
- Fluxbox desktop manager
- SSH server and client
- ALSA configuration and usage utilities
The Automatic Installation page provides a brief introduction on how to install the run-time Linux image.
Using Debian Linux on CL-SOM-AM57x
Connection and Logging In
Use the following username and password to login:
Account with administrative privileges:
cl-debian-armhf login: root Password: 111111
Regular user account:
cl-debian-armhf login: user Password: 111111
To login into the Linux system, you may use a serial console (ttyO2) at 115200 bps, or connect through the network, or use a keyboard and HDMI display.
X Windows system
CompuLab DEMO root filesystem image contains fully featured X server system with Fluxbox window manager. Before starting X server, connect USB mouse and keyboard to the system. You can run X server and Fluxbox window manager by typing startx.
Fluxbox window manager
CL-SOM-AM57x Debian Linux features installed Fluxbox package - a lightweight window manager for the X server system.
- Fluxbox provides configurable window decorations, a root menu to launch applications and a toolbar that shows the current workspace name, a set of application names and the current time. There is also a workspace menu which allows you to add or remove workspaces. The slit can be used to dock small applications, e.g. most of the bbtools can use slit.
- Fluxbox can iconify windows to the toolbar, in addition to adding the window to the Icons submenu of the workspace menu.
Visit Fluxbox Wiki and Official home page for more details.
Software Management
Debian Linux image for CL-SOM-AM57x includes all the information required to use Debian package management utilities. You can use apt-get and dpkg out of the box.
Display options
CL-SOM-AM57x evaluation platform has four video output interfaces: HDMI, LCD, DVI, and LVDS. Default configuration of Debian Linux for CL-SOM-AM57x uses HDMI (SB-SOM-AM57x J4 connector) as primary video output.
Touchscreen
CL-SOM-AM57x Evaluation Kit is equipped with Startek KD050C LCD 800x480 LCD touch panel. The touchscreen driver is modularized if you use default CL-SOM-AM57x configuration and is loaded by udev automatically on Linux boot. If the touchscreen driver is not loaded, the following command will load the touchscreen driver:
modprobe ads7846
Touchscreen calibration
A touchscreen device can be calibrated using xinput_calibrator utility.
To calibrate the touchscreen:
- Update the primary video output to the calibrated display type.
- Run X Server by issuing startx command
- Make sure the touchscreen driver is loaded
- Set the DISPLAY environment variable:
export DISPLAY=:0
- Run xinput_calibrator utility. For proper calibration you are required to touch the touchscreen corners and center in the following order: top-left, top-right, bottom-right, bottom-left, center.
- Create a file /usr/share/X11/xorg.conf.d/99-calibration.conf and paste there a snippet with the calibration results:
root@cl-debian-armhf:~# xinput_calibrator Setting calibration data: 0, 4095, 0, 4095 Calibrating EVDEV driver for "ADS7846 Touchscreen" id=6 current calibration values (from XInput): min_x=0, max_x=4095 and min_y=0, max_y=4095 Doing dynamic recalibration: Setting calibration data: 289, 3781, 3887, 227 --> Making the calibration permanent <-- copy the snippet below into '/etc/X11/xorg.conf.d/99-calibration.conf' (/usr/share/X11/xorg.conf.d/ in some distro's) Section "InputClass" Identifier "calibration" MatchProduct "ADS7846 Touchscreen" Option "Calibration" "289 3781 3887 227" Option "SwapAxes" "0" EndSection
Analog Audio
CL-SOM-AM57x provides an analog audio interface, which is registered as a standard ALSA sound card. Use aplay -l to list all soundcards and digital audio devices registered on the system:
root@debian-armhf:~# aplay -l **** List of PLAYBACK Hardware Devices **** card 0: clsomamx57xx [cl-som-amx57xx], device 0: davinci-mcasp.0-wm8731-hifi wm8731-hifi-0 [] Subdevices: 1/1 Subdevice #0: subdevice #0 card 1: H58040000encode [HDMI 58040000.encoder], device 0: HDMI 58040000.encoder snd-soc-dummy-dai-0 [] Subdevices: 1/1 Subdevice #0: subdevice #0
Analog Audio Settings
To enable the Analog audio playback, alsamixer or amixer applications can be used.
- alsamixer - set the “Output Mixer” control on.
or
- amixer - set the “Output Mixer HiFi Playback Switch” control on using command line interface:
root@debian-armhf:~# amixer cset numid=14 1 numid=14,iface=MIXER,name='Output Mixer HiFi Playback Switch' ; type=BOOLEAN,access=rw------,values=1 : values=on
Analog Audio Playback
In order to play back a sound file make use of the aplay application.
- aplay -L can be used for listing of all pcm devices.
Here is a sample output of aplay -L command:
root@debian-armhf:~# aplay -L
null
Discard all samples (playback) or generate zero samples (capture)
default:CARD=clsomamx57xx
cl-som-amx57xx,
Default Audio Device
sysdefault:CARD=clsomamx57xx
cl-som-amx57xx,
Default Audio Device
dmix:CARD=clsomamx57xx,DEV=0
cl-som-amx57xx,
Direct sample mixing device
dsnoop:CARD=clsomamx57xx,DEV=0
cl-som-amx57xx,
Direct sample snooping device
hw:CARD=clsomamx57xx,DEV=0
cl-som-amx57xx,
Direct hardware device without any conversions
plughw:CARD=clsomamx57xx,DEV=0
cl-som-amx57xx,
Hardware device with all software conversions
default:CARD=H58040000encode
HDMI 58040000.encoder,
Default Audio Device
sysdefault:CARD=H58040000encode
HDMI 58040000.encoder,
Default Audio Device
dmix:CARD=H58040000encode,DEV=0
HDMI 58040000.encoder,
Direct sample mixing device
dsnoop:CARD=H58040000encode,DEV=0
HDMI 58040000.encoder,
Direct sample snooping device
hw:CARD=H58040000encode,DEV=0
HDMI 58040000.encoder,
Direct hardware device without any conversions
plughw:CARD=H58040000encode,DEV=0
HDMI 58040000.encoder,
Hardware device with all software conversions
The next command can be used for audio play back:
root@cm-debian:~# aplay <wav-file>
Audio Input Settings
CL-SOM-AM57x provides an audio capturing feature from either Mic or Line In input sources. alsamixer or amixer can be used in order to switch between these inputs.
Mic
- alsamixer
- Line Input => 100
- Line => off
- Mic => on
- amixer
amixer cset numid=3 31 amixer cset numid=4 0 amixer cset numid=6 1 amixer cset numid=11 1
Line In
- alsamixer
- Line Input => 100
- Line => on
- Mic => off
- amixer
amixer cset numid=3 31 amixer cset numid=4 1 amixer cset numid=6 0 amixer cset numid=11 0
Sample Audio Recording
As soon as the correct input values have been set, audio signal can be captured. Here is a sample command that shows the arecord usage for capturing audio signal from the selected input line.
root@debian-armhf:~# arecord -f dat -t wav /tmp/out.wav
Bluetooth
CL-SOM-AM57x features Bluetooth 4.1 BLE interface. Following sections describe the initialization and simple use cases of Bluetooth device.
Host Controller Interface (HCI) Initialization
- For TI SDK kernel v4.1.13, create a symbolic link to the bluetooth UART:
root@debian-armhf:~# ln -sf /dev/ttyS9 /dev/ttyO9
- Attach the ttyO9 serial port to the HCI Bluetooth subsystem:
root@debian-armhf:~# echo "enabled" > /sys/bus/platform/devices/reg-userspace-consumer.0/state root@debian-armhf:~# hciattach -s 115200 /dev/ttyO9 texas 3000000 Found a Texas Instruments' chip! Firmware file : /lib/firmware/ti-connectivity/TIInit_11.8.32.bts Loaded BTS script version 1 texas: changing baud rate to 3000000, flow control to 1 [ 89.019183] Bluetooth: Core ver 2.21 [ 89.023025] NET: Registered protocol family 31 [ 89.027726] Bluetooth: HCI device and connection manager initialized [ 89.034581] Bluetooth: HCI socket layer initialized [ 89.039779] Bluetooth: L2CAP socket layer initialized [ 89.045296] Bluetooth: SCO socket layer initialized [ 89.055192] Bluetooth: HCI UART driver ver 2.3 [ 89.059914] Bluetooth: HCI UART protocol H4 registered [ 89.065306] Bluetooth: HCI UART protocol LL registered [ 89.308172] Bluetooth: BNEP (Ethernet Emulation) ver 1.3 [ 89.313747] Bluetooth: BNEP filters: protocol multicast [ 89.319275] Bluetooth: BNEP socket layer initialized Device setup complete
- Run HCI device configuration utility to retrieve detailed information about the Bluetooth device:
root@debian-armhf:~# hciconfig -a
hci0: Type: BR/EDR Bus: UART
BD Address: 54:4A:16:13:0D:42 ACL MTU: 1021:6 SCO MTU: 180:4
UP RUNNING PSCAN
RX bytes:704 acl:0 sco:0 events:43 errors:0
TX bytes:1782 acl:0 sco:0 commands:43 errors:0
Features: 0xff 0xfe 0x2d 0xfe 0xdb 0xff 0x7b 0x87
Packet type: DM1 DM3 DM5 DH1 DH3 DH5 HV1 HV2 HV3
Link policy: RSWITCH HOLD SNIFF
Link mode: SLAVE ACCEPT
Name: 'cl-som-am57x-sid'
Class: 0x000000
Service Classes: Unspecified
Device Class: Miscellaneous,
HCI Version: 4.1 (0x7) Revision: 0x0
LMP Version: 4.1 (0x7) Subversion: 0xac08
Manufacturer: Texas Instruments Inc. (13)
- If the HCI device is not running, use the below command to enable the HCI device:
root@debian-armhf:~# hciconfig hci0 up
- HCI Inquire remote devices.
root@debian-armhf:~# hcitool scan Scanning ...
Bluez5 & PulseAudio
Debian stretch/sid is using BlueZ 5 and PluseAudio 5.
BlueZ 5 dropped support for alsa, and uses PulseAudio.
PulseAudio 5 only supports the A2DP profile and not HSP/HFP.
- Software to install pulseaudio, pulseaudio-module-bluetooth
Install and configure PulseAudio
root@debian-armhf:~# apt-get update root@debian-armhf:~# apt-get install pulseaudio pulseaudio-module-bluetooth
- Create a systemd service for running pulseaudio as the pulse user.
root@debian-armhf:~# cat << eof > /etc/systemd/system/pulseaudio.service [Unit] Description=Pulse Audio [Service] Type=simple ExecStart=/usr/bin/pulseaudio --system --disallow-exit --disable-shm [Install] WantedBy=multi-user.target eof root@debian-armhf:~# chown pulse:pulse /etc/systemd/system/pulseaudio.service
- Create a dbus configuration file for running pulseaudio. Give the pulse user permission to use Bluetooth.
root@debian-armhf:~# cat << eof > /etc/dbus-1/system.d/pulseaudio-bluetooth.conf
<busconfig>
<policy user="pulse">
<allow send_destination="org.bluez"/>
</policy>
</busconfig>
eof
root@debian-armhf:~# chmod 0666 /etc/dbus-1/system.d/pulseaudio-bluetooth.conf
- Paste the following lines to the end of /etc/pulse/system.pa:
root@debian-armhf:~# cat << eof >> /etc/pulse/system.pa ### Automatically load driver modules for Bluetooth hardware .ifexists module-bluetooth-policy.so load-module module-bluetooth-policy .endif .ifexists module-bluetooth-discover.so load-module module-bluetooth-discover .endif eof
- Create /var/run/pulse/.config/pulse directory and fix the ownership.
root@debian-armhf:~# mkdir -p /var/run/pulse/.config/pulse root@debian-armhf:~# chown -R pulse:pulse /var/run/pulse
- Add root to the pulse-access,audio groups
root@debian-armhf:~# usermod -a -G pulse-access,audio root
Start PulseAudio
- Start PulseAudio service
root@debian-armhf:~# systemctl daemon-reload root@debian-armhf:~# systemctl start pulseaudio.service
- Make sure that the service is active, running and reports on no error.
root@debian-armhf:~# systemctl status pulseaudio.service
Loaded: loaded (/etc/systemd/system/pulseaudio.service; disabled)
Active: active (running) since Mon 2015-07-20 12:00:13 UTC; 1min 34s ago
Main PID: 805 (pulseaudio)
CGroup: /system.slice/pulseaudio.service
└─805 /usr/bin/pulseaudio --system --disallow-exit --disable-shm
Bluez5 pairing
PulseAudio 5.x supports A2DP by default. Make sure the following packages are installed: pulseaudio pulseaudio-module-bluetooth pulseaudio-utils, bluez, bluez-tools.
- Start the Bluetooth system:
root@debian-armhf:~# systemctl start bluetooth
Now we can use the bluetoothctl command line utility to pair and connect. Run
root@debian-armhf:~# bluetoothctl [bluetooth]#
to be greeted by its internal command prompt.Then enter:
[bluetooth]# power on [bluetooth]# agent on [bluetooth]# default-agent [bluetooth]# scan on
Make sure that an A2DP device is in pairing mode. It should be discovered shortly. For example,
[NEW] Device 00:07:A4:F2:B3:CB Motorola HT820
shows a device that calls itself "Motorola HT820" and has MAC address 00:07:A4:F2:B3:CB. Use the MAC address to initiate the pairing:
[bluetooth]# pair 00:07:A4:F2:B3:CB
After pairing, connect the device:
[bluetooth]# connect 00:07:A4:F2:B3:CB
After the successful connection, the new output device will be created in PulseAudio.
Scanning can be disabled now:
[bluetooth]# scan off
Exit the program:
[bluetooth]# exit
Playback using PulseAudio
|
Next examples assume that the device mac address is 00_07_A4_F2_B3_CB |
- Show the PulseAudio device
root@debian-armhf:~# pactl list cards | awk '/00_07_A4_F2_B3_CB/' RS=""
Card #1
Name: bluez_card.00_07_A4_F2_B3_CB
Driver: module-bluez5-device.c
Owner Module: 13
Properties:
device.description = "Motorola HT820"
device.string = "00:07:A4:F2:B3:CB"
device.api = "bluez"
device.class = "sound"
device.bus = "bluetooth"
device.form_factor = "headset"
bluez.path = "/org/bluez/hci0/dev_00_07_A4_F2_B3_CB"
bluez.class = "0x240404"
bluez.alias = "Motorola HT820"
device.icon_name = "audio-headset-bluetooth"
device.intended_roles = "phone"
Profiles:
headset_head_unit: Headset Head Unit (HSP/HFP) (sinks: 1, sources: 1, priority: 20, available: no)
a2dp_sink: High Fidelity Playback (A2DP Sink) (sinks: 1, sources: 0, priority: 10, available: yes)
off: Off (sinks: 0, sources: 0, priority: 0, available: yes)
Active Profile: a2dp_sink
Ports:
headset-output: Headset (priority: 0, latency offset: 0 usec)
Part of profile(s): headset_head_unit, a2dp_sink
headset-input: Headset (priority: 0, latency offset: 0 usec, not available)
Part of profile(s): headset_head_unit
- Make sure the active card profile is a2dp_sink. Otherwise switch to it:
# pactl set-card-profile 1 a2dp_sink
- Show the PulseAudio sink
root@debian-armhf:~# pactl list sinks | awk '/00_07_A4_F2_B3_CB/' RS=""
Sink #1
State: SUSPENDED
Name: bluez_sink.00_07_A4_F2_B3_CB
Description: Motorola HT820
Driver: module-bluez5-device.c
Sample Specification: s16le 2ch 48000Hz
Channel Map: front-left,front-right
Owner Module: 13
Mute: no
Volume: front-left: 65536 / 100% / 0.00 dB, front-right: 65536 / 100% / 0.00 dB
balance 0.00
Base Volume: 65536 / 100% / 0.00 dB
Monitor Source: bluez_sink.00_07_A4_F2_B3_CB.monitor
Latency: 0 usec, configured 0 usec
Flags: HARDWARE DECIBEL_VOLUME LATENCY
Properties:
bluetooth.protocol = "a2dp_sink"
device.description = "Motorola HT820"
device.string = "00:07:A4:F2:B3:CB"
device.api = "bluez"
device.class = "sound"
device.bus = "bluetooth"
device.form_factor = "headset"
bluez.path = "/org/bluez/hci0/dev_00_07_A4_F2_B3_CB"
bluez.class = "0x240404"
bluez.alias = "Motorola HT820"
device.icon_name = "audio-headset-bluetooth"
device.intended_roles = "phone"
Ports:
headset-output: Headset (priority: 0)
Active Port: headset-output
Formats:
pcm
- Play sound using paplay. Example:
root@debian-armhf:~# paplay -d bluez_sink.00_07_A4_F2_B3_CB /path/to/<audio-file.wav>
Obex FTP service
The OBject EXchange protocol (OBEX) can be used to exchange all kind of objects like files, pictures, calendar entries (vCal) and business cards (vCard) over bluetooth, IrDA, USB and serial cable links.
Use the following command to install file transfer utility for devices that use the OBEX protocol:
root@debian-armhf:~# apt-get update root@debian-armhf:~# apt-get install obexftp
Following examples demonstrate its usage with mobile phone device.
- Enable bluetooth on the phone. On CL-SOM-AM57x, scan for available devices to find out phone's BT address:
root@cl-debian-armhf:~# hcitool scan Scanning ... 00:15:2A:20:63:94 Nokia 6230i
- Ensure the phone supports Obex FTP service:
root@cl-debian-armhf:~# sdptool search FTP
Inquiring ...
Searching for FTP on 00:15:2A:20:63:94 ...
Service Name: OBEX File Transfer
Service RecHandle: 0x100de
Service Class ID List:
"OBEX File Transfer" (0x1106)
Protocol Descriptor List:
"L2CAP" (0x0100)
"RFCOMM" (0x0003)
Channel: 10
"OBEX" (0x0008)
Language Base Attr List:
code_ISO639: 0x656e
encoding: 0x6a
base_offset: 0x100
Profile Descriptor List:
"OBEX File Transfer" (0x1106)
Version: 0x0100
- Follow the section "Bluez5 pairing" to pair the CL-SOM-AM57x module with the phone.
- List phone's root folder:
root@cl-debian-armhf:~# obexftp -b 00:15:2A:20:63:94 --list
Browsing 00:15:2A:20:63:94 ...
Connecting..\done
Tried to connect for 579ms
Receiving "(null)".../<?xml version="1.0"?>
<!DOCTYPE folder-listing SYSTEM "obex-folder-listing.dtd"
[ <!ATTLIST folder mem-type CDATA #IMPLIED> ]>
<folder-listing version="1.0">
<folder name="EXTENTSION" user-perm="RW" mem-type="MMC"/>
<folder name="Images" created="19800101T000000" user-perm="R" mem-type="DEV"/>
<folder name="Video clips" created="19800101T000000" user-perm="R" mem-type="DEV"/>
<folder name="Music files" created="19800101T000000" user-perm="R" mem-type="DEV"/>
<folder name="Themes" created="19800101T000000" user-perm="RW" mem-type="DEV"/>
<folder name="Graphics" created="19800101T000000" user-perm="R" mem-type="DEV"/>
<folder name="Tones" created="19800101T000000" user-perm="R" mem-type="DEV"/>
<folder name="Recordings" created="19800101T000000" user-perm="R" mem-type="DEV"/>
</folder-listing>
done
Disconnecting..-done
- Transfer a file from CL-SOM-AM57x to the phone:
root@cl-debian-armhf:~# obexftp -b 00:15:2A:20:63:94 --put test_file.txt Browsing 00:15:2A:20:63:94 ... Connecting..\done Tried to connect for 380ms Sending "test_file.txt"...|done Disconnecting../done
- Retrieve a file from the phone to CL-SOM-AM57x:
root@cl-debian-armhf:~# obexftp -b 00:15:2A:20:63:94 --get test_file.txt Browsing 00:15:2A:20:63:94 ... Connecting..\done Tried to connect for 267ms Receiving "test_file.txt".../done Disconnecting..-done
WiFi
CL-SOM-AM57x features 802.11b/g/n wireless connectivity solution, implemented with the TI WiLink 8 WL1801 Wireless controller module.
WiFi Initialization
- The driver gets loaded automatically. Make sure that the WiFi driver is loaded:
root@cl-debian-armhf:~# lsmod | grep wl wl18xx 89863 0 wlcore 183512 1 wl18xx mac80211 606845 2 wl18xx,wlcore cfg80211 491510 3 mac80211,wl18xx,wlcore wlcore_sdio 6495 0
- iwconfig command from wireless-tools package can be used to retrieve detailed information about the WiFi interfaces:
root@cl-debian-armhf:~# iwconfig wlan0
wlan0 IEEE 802.11abgn ESSID:off/any
Mode:Managed Access Point: Not-Associated Tx-Power=0 dBm
Retry short limit:7 RTS thr:off Fragment thr:off
Encryption key:off
Power Management:off
- WLAN interface activating:
root@cl-debian-armhf:~# ifconfig wlan0 up [ 180.395059] wlcore: PHY firmware version: Rev 8.2.0.0.232 [ 180.504299] wlcore: firmware booted (Rev 8.9.0.0.48)
- Sample WiFi scanning:
root@cl-debian-armhf:~# iwlist wlan0 scan
The output will show the list of Access Points and Ad-Hoc cells in range. For more information about connecting to wireless networks and tuning WiFi interfaces refer to “wpa_supplicant” and “wireless-tools” man pages.
wpa_supplicant
- Configuration sample
wpa_supplicant requires a configuration file to be created in order to get connected to a scanned wireless network.
Make use of the example bellow and put the network name and the password into the "ssid/psk" fields.
root@cl-debian-armhf:~# cat << eof > /etc/wpa_supplicant.conf
ctrl_interface=/var/run/wpa_supplicant
network={
ssid="wireless_network_name"
key_mgmt=WPA-PSK
psk="wireless_network_password"
}
eof
- Sample run
root@cl-debian-armhf:~# ifconfig wlan0 up root@cl-debian-armhf:~# wpa_supplicant -B -Dwext -c /etc/wpa_supplicant.conf -i wlan0 root@cl-debian-armhf:~# dhclient wlan0
Controller–area network (CAN)
The CL-SOM-AM57x features a Dual Controller Area Network (DCAN) Modules integrated into Sitara AM57x SoC. The DCAN implements full CAN protocol version 2.0B. It supports both the base (standard) and the extended frame format as well as a programmable data bit rate with maximum of 1Mbit/s.
Loading CAN modules
If the DCAN driver and/or Raw CAN protocol compiled as module(s), they must be loaded prior to enabling CAN interface.
- Load Raw CAN protocol module:
root@cl-debian-armhf:~# modprobe can-raw can: controller area network core (rev 20120528 abi 9) NET: Registered protocol family 29 can: raw protocol (rev 20120528)
CAN interface configuration
It is recommended configure the CAN interface, with the iproute2 utilities.
- To make sure the right ip utility is used, run:
root@cl-debian-armhf:~# ip -V ip utility, iproute2-ss140804
- Configure the CAN interface bit-rate to 125 Kbits/sec (values of up to 1Mbit/sec are supported):
root@cl-debian-armhf:~# ip link set can0 type can bitrate 125000
- Enable the CAN interface:
root@cl-debian-armhf:~# ip link set can0 up net can0: c_can_hw_raminit_wait_syscon: time out c_can_platform 4ae3c000.can can0: setting BTR=1c09 BRPE=0000
Send/Receive packets
Use cansend and candump utilities to send and receive packets via CAN interface.
- Send standard CAN frame (on the first device):
root@cl-debian-armhf:~# cansend can0 111#1122334455667788
- Send extended CAN frame (on the first device):
root@cl-debian-armhf:~# cansend can0 11111111#1122334455667788
- Dump all received data frames as well as error frames (on the second device):
root@cl-debian-armhf:~# candump any,0:0,#FFFFFFFF can0 111 [8] 11 22 33 44 55 66 77 88 can0 11111111 [8] 11 22 33 44 55 66 77 88
MMC/SD
The support for MMC/SD card on CL-SOM-AM57x is built into the Linux kernel. To mount the memory card, monitor /proc/partitions to see what partitions were detected on the MMC/SD card. For example, suppose MMC/SD partition you'd like to mount is mmcblk0p1 then:
mkdir -p /mnt/mmcblk0p1 && mount /dev/mmcblk0p1 /mnt/mmcblk0p1
USB 3.0 Dual-Role-Device
CL-SOM-AM57x has USB DWC3 (XHCI) based controller. It features SuperSpeed (SS) USB 3.0 Dual-Role-Device (DRD) subsystem with integrated SS (USB3.0) PHY and HS/FS (USB2.0) PHY. Current Linux kernel support of DWC3 features does not allow dynamic role (host/device) switching in runtime. By default, host role is assigned to CL-SOM-AM57x USB 3.0 port.
RTC
To set the date and write it into the RTC do the following:
root@cl-debian-armhf:~# date -s "31 JUL 2015 10:00:00" Fri Jul 31 10:00:00 UTC 2015 root@cl-debian-armhf:~# /sbin/hwclock --systohc root@cl-debian-armhf:~# hwclock -w Fri Jul 31 10:00:13 2015 -1.066224 seconds
To access the RTC time and date run:
root@cl-debian-armhf:~# hwclock Fri 31 Jul 2015 10:00:24 AM UTC -0.083102 seconds
