Difference between revisions of "DESK-MX8M-L/Peripherals/USB1 OTG"
| Line 22: | Line 22: | ||
=== Device tree configuration === | === Device tree configuration === | ||
| + | |||
| + | ==== ORCA ==== | ||
| + | |||
Here below an example of device tree configuration used on standard DAVE's kit for the ORCA SOM: | Here below an example of device tree configuration used on standard DAVE's kit for the ORCA SOM: | ||
| Line 49: | Line 52: | ||
</pre> | </pre> | ||
| + | ==== MINI ==== | ||
| + | |||
| + | Here below an example of device tree configuration used on standard DAVE's kit for the MINI SOM: | ||
| + | |||
| + | From <code>imx8mm-mito8mmini.dts</code>: | ||
| + | |||
| + | <pre> | ||
| + | &usbotg1 { | ||
| + | dr_mode = "otg"; | ||
| + | picophy,pre-emp-curr-control = <3>; | ||
| + | picophy,dc-vol-level-adjust = <7>; | ||
| + | disable-over-current; | ||
| + | srp-disable; | ||
| + | hnp-disable; | ||
| + | adp-disable; | ||
| + | status = "okay"; | ||
| + | }; | ||
| + | |||
| + | |||
| + | </pre> | ||
===Accessing the peripheral=== | ===Accessing the peripheral=== | ||
| + | |||
| + | This procedure is the same for both ORCA and MINI. | ||
====Linux messages at boot time==== | ====Linux messages at boot time==== | ||
Revision as of 14:53, 15 February 2023
| HOME | SOMs | SBCs | ToloMEO Embedded Assistant |  GET A QUOTE
|
 ONLINE HELPDESK
|
| Roadmap | IoT Services | ML/AI services | Embedded Design Services |
| History | |||
|---|---|---|---|
| Version | Issue Date | Notes | |
| 1.0.0 | Jan 2022 | First DESK-MX8M release | |
| 2.0.0 | Feb 2023 | DESK-MX8M-L-2.0.0 | |
Contents
Peripheral USB OTG[edit | edit source]
Device tree configuration[edit | edit source]
ORCA[edit | edit source]
Here below an example of device tree configuration used on standard DAVE's kit for the ORCA SOM:
From imx8mp-mito8mplus-cb1001.dts:
&usb3_phy1 {
fsl,phy-tx-preemp-amp-tune = <2>;
status = "okay";
};
&usb3_1 {
status = "okay";
};
&usb_dwc3_1 {
dr_mode = "otg";
extcon = <&extcon_usbotg2>;
hnp-disable;
srp-disable;
adp-disable;
rsp-disable;
disable-over-current;
status = "okay";
};
MINI[edit | edit source]
Here below an example of device tree configuration used on standard DAVE's kit for the MINI SOM:
From imx8mm-mito8mmini.dts:
&usbotg1 {
dr_mode = "otg";
picophy,pre-emp-curr-control = <3>;
picophy,dc-vol-level-adjust = <7>;
disable-over-current;
srp-disable;
hnp-disable;
adp-disable;
status = "okay";
};
Accessing the peripheral[edit | edit source]
This procedure is the same for both ORCA and MINI.
Linux messages at boot time[edit | edit source]
... ... [ 4.954820] usb_otg_vbus: disabling ... ...
Usage with mass-storage[edit | edit source]
root@desk-mx8mp:~# dd if=/dev/zero of=mass_storage count=256 bs=1M 256+0 records in 256+0 records out 268435456 bytes (268 MB, 256 MiB) copied, 0.844688 s, 318 MB/s root@desk-mx8mp:~# mkfs.msdos mass_storage mkfs.fat 4.1 (2017-01-24) root@desk-mx8mp:~# mkdir loop root@desk-mx8mp:~# mount -o loop mass_storage loop root@desk-mx8mp:~# echo "Test USB OTG with mass storage device" > loop/usb.txt root@desk-mx8mp:~# umount loop root@desk-mx8mp:~#
then insert the g_mass_storage kernel module driver enabling an Windows PC to see it as a removable device
root@desk-mx8mp:~# modprobe g_mass_storage removable=y file=mass_storage [ 891.807023] Mass Storage Function, version: 2009/09/11 [ 891.813145] LUN: removable file: (no medium) [ 891.818901] LUN: removable file: /home/root/mass_storage [ 891.824754] Number of LUNs=1 [ 891.827901] g_mass_storage gadget: Mass Storage Gadget, version: 2009/09/11 [ 891.834955] g_mass_storage gadget: userspace failed to provide iSerialNumber [ 891.842109] g_mass_storage gadget: g_mass_storage ready root@desk-mx8mp:~#
Once the USB cable is connected to the PC, the kernel prints the following messages:
root@desk-mx6:~# [ 892.036840] g_mass_storage gadget: high-speed config #1: Linux File-Backed Storage
and the Windows PC activate the driver and the disk is available as a Drive Unit (with the usb.txt file available).
