DESK-MX8M-L/Peripherals/USB2 OTG
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| DESK-MX8M-L-2.0.0 release | |||
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| 2024/04/11 | DESK-MX8M-L-4.1.0 release | ||
Contents
Peripheral USB2 OTG[edit | edit source]
Device tree configuration[edit | edit source]
ORCA SOM[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";
};
...
...
MITO 8M Mini[edit | edit source]
Here below an example of device tree configuration used on standard DAVE's kit for the MITO 8M Mini:
From imx8mm-mito8mmini.dtsi:
...
...
&usbotg2 {
dr_mode = "host";
picophy,pre-emp-curr-control = <3>;
picophy,dc-vol-level-adjust = <7>;
status = "disabled";
};
...
...
From imx8mm-mito8mmini-sbcx.dts:
...
...
/ {
regulators: regulators {
compatible = "simple-bus";
#address-cells = <1>;
#size-cells = <0>;
reg_usb_pwr: usb_pwr {
compatible = "regulator-fixed";
regulator-name = "usb_pwr_en";
regulator-min-microvolt = <5000000>;
regulator-max-microvolt = <5000000>;
gpio = <&gpio1 12 GPIO_ACTIVE_HIGH>;
enable-active-high;
};
...
...
};
};
...
...
&usbotg2 {
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_usb_pwr>;
vbus-supply = <®_usb_pwr>;
status = "okay";
};
...
...
&iomuxc {
...
...
pinctrl_usb_pwr: usbpwrgrp {
fsl,pins = <
MX8MM_IOMUXC_GPIO1_IO12_GPIO1_IO12 0x19
>;
};
...
...
};
... ...
Accessing the peripheral SBC ORCA[edit | edit source]
Linux messages in host mode[edit | edit source]
When a USB 2.0 peripheral is inserted, in the following example a memory mass storage device, the kernel recognizes the device (i.e. class, vendor id, product id, etc.)
root@desk-mx8mp:~# [ 949.406404] [ 6491.481175] usb 3-1: new high-speed USB device number 3 using xhci-hcd [ 6491.639810] usb-storage 3-1:1.0: USB Mass Storage device detected [ 6491.646905] scsi host0: usb-storage 3-1:1.0 [ 6493.775259] scsi 0:0:0:0: Direct-Access Fanxiang F206 1100 PQ: 0 ANSI: 4 [ 6493.786654] sd 0:0:0:0: [sda] 61440000 512-byte logical blocks: (31.5 GB/29.3 GiB) [ 6493.795475] sd 0:0:0:0: [sda] Write Protect is off [ 6493.801799] sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA [ 6493.818546] sda: sda1 [ 6493.824653] sd 0:0:0:0: [sda] Attached SCSI removable disk root@desk-mx8mp:~#
When a USB 3.0 peripheral is inserted, in the following example a memory mass storage device, the kernel recognizes the device (i.e. class, vendor id, product id, etc.)
root@desk-mx8mp:~# [ 6798.669673] usb 4-1: new SuperSpeed USB device number 3 using xhci-hcd [ 6798.703673] usb-storage 4-1:1.0: USB Mass Storage device detected [ 6798.710479] scsi host1: usb-storage 4-1:1.0 [ 6799.719808] scsi 1:0:0:0: Direct-Access Wilk USB DISK 3.0 PMAP PQ: 0 ANSI: 6 [ 6799.732902] sd 1:0:0:0: [sdb] 60628992 512-byte logical blocks: (31.0 GB/28.9 GiB) [ 6799.741747] sd 1:0:0:0: [sdb] Write Protect is off [ 6799.747177] sd 1:0:0:0: [sdb] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA [ 6799.934800] sdb: [ 6799.940848] sd 1:0:0:0: [sdb] Attached SCSI removable disk
Usage in device mode 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, 0.987911 s, 272 MB/s root@desk-mx8mp:~# mkfs.msdos mass_storage mkfs.fat 4.2 (2021-01-31) root@desk-mx8mp:~# mkdir loop root@desk-mx8mp:~# mount -o loop mass_storage loop [ 6664.248804] loop0: detected capacity change from 0 to 524288 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 [ 6677.844877] Mass Storage Function, version: 2009/09/11 [ 6677.850190] LUN: removable file: (no medium) [ 6677.854585] LUN: removable file: /home/root/mass_storage [ 6677.859933] Number of LUNs=1 [ 6677.863239] g_mass_storage gadget: Mass Storage Gadget, version: 2009/09/11 [ 6677.870221] g_mass_storage gadget: userspace failed to provide iSerialNumber [ 6677.877281] 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-mx8mp:~# [ 1493.477167] 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).
Accessing the peripheral MITO 8M Mini[edit | edit source]
Linux messages[edit | edit source]
When a USB 2.0 peripheral is inserted, in the following example a memory mass storage device, the kernel recognizes the device (i.e. class, vendor id, product id, etc.)
root@desk-mx8mm:~# [ 22.858909] usb 1-1: new high-speed USB device number 2 using ci_hdrc [ 23.022240] usb-storage 1-1:1.0: USB Mass Storage device detected [ 23.028819] scsi host0: usb-storage 1-1:1.0 [ 24.045317] scsi 0:0:0:0: Direct-Access SanDisk Cruzer Force 1.00 PQ: 0 ANSI: 6 [ 24.055280] sd 0:0:0:0: [sda] 60088320 512-byte logical blocks: (30.8 GB/28.7 GiB) [ 24.063993] sd 0:0:0:0: [sda] Write Protect is off [ 24.069617] sd 0:0:0:0: [sda] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA [ 24.142194] sda: sda1 [ 24.150358] sd 0:0:0:0: [sda] Attached SCSI removable disk
Additional information in host mode[edit | edit source]
If the root file system configuration does not automatically mount the partition, it is possible to mount the device using the following command:
root@desk-mx8mp:~# mkdir -p /mnt/usb root@desk-mx8mp:~# mount /dev/sda1 /mnt/usb [ 1245.415662] FAT-fs (sda1): Volume was not properly unmounted. Some data may be corrupt. Please run fsck. root@desk-mx8mp:~# ls -la /mnt/usb total 128 drwxr-xr-x 10 root root 4096 Jan 1 1970 . drwxr-xr-x 3 root root 4096 Dec 30 11:24 .. drwxr-xr-x 2 root root 4096 May 13 2021 System Volume Information drwxr-xr-x 2 root root 4096 Nov 17 15:27 boot -rwxr-xr-x 1 root root 8016 Nov 17 15:27 boot.scr -rwxr-xr-x 1 root root 1712 Dec 10 16:16 config.txt drwxr-xr-x 2 root root 4096 Nov 17 15:27 rfs -rwxr-xr-x 1 root root 57458 Nov 17 15:27 run-system-update.sh -rwxr-xr-x 1 root root 531 Nov 17 15:27 settings.txt
