DESK-MX6UL-L/Peripherals/USB Host
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| Version | Issue Date | Notes | |
| Jul 2021 | First DESK release | ||
| 2.0.0 | Feb 2022 | DESK 3.0.0 release | |
Contents
Peripheral USB Host[edit | edit source]
The USB Host port requires to configure the USB VBUS regulator and the gpio used for enabling the 5V USB power switch.
Device tree configuration[edit | edit source]
Here below an example of device tree configuration used on standard DAVE's kit for the AXEL ULite SOM:
From imx6ul-axelulite-cb003a.dts:
reg_usb_otg1_vbus: regulator@2 {
compatible = "regulator-fixed";
reg = <2>;
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_usb_otg1>;
regulator-name = "usb_otg1_vbus";
regulator-min-microvolt = <5000000>;
regulator-max-microvolt = <5000000>;
gpio = <&gpio1 18 GPIO_ACTIVE_HIGH>;
enable-active-high;
};
...
...
&usbotg1 {
vbus-supply = <®_usb_otg1_vbus>;
disable-over-current;
dr_mode = "host";
status = "okay";
};
...
...
&iomuxc {
pinctrl-0 = <&pinctrl_hog_gpios>;
imx6ul-axelulite {
...
...
pinctrl_usb_otg1: usbotg1grp {
fsl,pins = <
MX6UL_PAD_UART1_CTS_B__GPIO1_IO18 0x10b0 /* HOST PWR */
MX6UL_PAD_GPIO1_IO03__GPIO1_IO03 0x10b0 /* HOST OC */
>;
};
};
Accessing the peripheral[edit | edit source]
Linux messages at boot time[edit | edit source]
When a USB peripheral is inserted, in the following example a memory mass storage device, the kernel recognizes the device (i.e. xlass, vendor id, product id, etc.)
[ 39.935600] usb 1-1: new high-speed USB device number 2 using ci_hdrc [ 40.138049] usb 1-1: New USB device found, idVendor=0781, idProduct=5591, bcdDevice= 1.00 [ 40.146476] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3 [ 40.153786] usb 1-1: Product: SanDisk 3.2Gen1 [ 40.165109] usb 1-1: Manufacturer: USB [ 40.172245] usb 1-1: SerialNumber: 03017128082020175157 [ 40.189949] usb-storage 1-1:1.0: USB Mass Storage device detected [ 40.209663] scsi host0: usb-storage 1-1:1.0 [ 41.297685] scsi 0:0:0:0: Direct-Access USB SanDisk 3.2Gen1 1.00 PQ: 0 ANSI: 6 [ 41.321918] sd 0:0:0:0: [sda] 30031872 512-byte logical blocks: (15.4 GB/14.3 GiB) [ 41.337048] sd 0:0:0:0: [sda] Write Protect is off [ 41.341891] sd 0:0:0:0: [sda] Mode Sense: 43 00 00 00 [ 41.355746] sd 0:0:0:0: [sda] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA [ 41.443001] sda: sda1 [ 41.464325] sd 0:0:0:0: [sda] Attached SCSI removable disk [ 43.344264] EXT4-fs (sda1): mounted filesystem with ordered data mode. Opts: (null)
Additional information[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-mx6ul-axelulite:~# mkdir -p /mnt/usb root@desk-mx6ul-axelulite:~# mount /dev/sda1 /mnt/usb/ root@desk-mx6ul-axelulite:~# ls -la /mnt/usb/ total 24 drwxr-xr-x 3 root root 4096 Feb 24 14:16 . drwxr-xr-x 4 root root 4096 Feb 27 18:15 .. drwx------ 2 root root 16384 Feb 24 14:16 lost+found -rwxr-xr-x 1 root root 6881192 Feb 24 14:16 uImage
