iMX6 USB OTG功能开发与测试

USB接口上有4个管脚，OTG功能有5个。原来4个分别是电 D+ D- 地。 现在增加了一个ID。这个ID线就决定了自己做主设备还是从设备。如果ID线是高则自己是从设备，反之是主设备。

USB_OTG_ID定义为W23，即GPIO1_IO24

/test/gpio_get.sh24用来读出gpio value。读出来总是0:低电平。所以也不知道前面这句描述是对是错了。



imx6 kernel configas:

-> USB GadgetDrivers (<choice> [=m])

->File-backedStorage Gadget(USB_FILE_STORAGE [=m]) 。记得：不是选massstorage. 而且选模块方式，以方便安装模块时输入参数。



内置驱动时，测试打印：

g_file_storagegadget: controller 'fsl-usb2-udc' not recognized

g_file_storagegadget: No serial-number string provided!

g_file_storagegadget: no file given for LUN0

显然，这就是模块参数未给定导致的。



编译模块：

makeM=drivers/usb/gadget/ modules

得到

root@ubuntu:/home/imx6s/linux-3.0.101#make M=drivers/usb/gadget/ modules

Building modules, stage 2.

MODPOST 1 modules

LD [M] drivers/usb/gadget/g_file_storage.ko



root@imx6s ~$insmod /lib/modules/g_file_storage.ko file=/dev/mmcblk0

g_file_storagegadget: controller 'fsl-usb2-udc' not recognized

g_file_storagegadget: No serial-number string provided!

g_file_storagegadget: File-backed Storage Gadget, version: 1 September 2010

g_file_storagegadget: Number of LUNs=1

g_file_storagegadget-lun0: ro=0, nofua=0, file: /dev/mmcblk0

Suspend udc forOTG auto detect

fsl-usb2-udc: bindto driver g_file_storage

root@imx6s ~$g_file_storage gadget: high speed config #1



win7也同时显示说找到设备驱动，磁盘驱动器：linux File-Stor Gadget USB Device

下面反复插拔USB-PC线几次，然后换成USB-SD卡，都是可以的。但再换回USB-PC线就不行了，找不见设备。

root@imx6s ~$g_file_storage gadget: high speed config #1



root@imx6s ~$g_file_storage gadget: high speed config #1



root@imx6s ~$

root@imx6s ~$g_file_storage gadget: high speed config #1



root@imx6s ~$

root@imx6s ~$ usb1-1: new high speed USB device number 2 using fsl-ehci

usb 1-1: devicev0930 p6545 is not supported

scsi0 :usb-storage 1-1:1.0

scsi 0:0:0:0:Direct-Access TOSHIBA TransMemory PMAP PQ: 0 ANSI: 4

sd 0:0:0:0: [sda]30489408 512-byte logical blocks: (15.6 GB/14.5 GiB)

sd 0:0:0:0: [sda]Write Protect is off

sd 0:0:0:0: [sda]No Caching mode page found

sd 0:0:0:0: [sda]Assuming drive cache: write through

sd 0:0:0:0: [sda]No Caching mode page found

sd 0:0:0:0: [sda]Assuming drive cache: write through

sda: sda1

sd 0:0:0:0: [sda]No Caching mode page found

sd 0:0:0:0: [sda]Assuming drive cache: write through

sd 0:0:0:0: [sda]Attached SCSI removable disk



root@imx6s ~$ usb1-1: USB disconnect, device number 2

wait otg vbuschange timeout!



root@imx6s ~$ usb1-1: new high speed USB device number 3 using fsl-ehci

usb 1-1: devicev0930 p6545 is not supported

scsi1 :usb-storage 1-1:1.0

scsi 1:0:0:0:Direct-Access TOSHIBA TransMemory PMAP PQ: 0 ANSI:4

sd 1:0:0:0: [sda]30489408 512-byte logical blocks: (15.6 GB/14.5 GiB)

sd 1:0:0:0: [sda]Write Protect is off

sd 1:0:0:0: [sda]No Caching mode page found

sd 1:0:0:0: [sda]Assuming drive cache: write through

sd 1:0:0:0: [sda]No Caching mode page found

sd 1:0:0:0: [sda]Assuming drive cache: write through

sda: sda1

sd 1:0:0:0: [sda]No Caching mode page found

sd 1:0:0:0: [sda]Assuming drive cache: write through

sd 1:0:0:0: [sda]Attached SCSI removable disk



root@imx6s ~$

root@imx6s ~$ usb1-1: USB disconnect, device number 3

wait otgvbus change timeout!



root@imx6s ~$

root@imx6s ~$ usb1-1: new high speed USB device number 4 using fsl-ehci

usb 1-1: devicev0930 p6545 is not supported

scsi2 :usb-storage 1-1:1.0

scsi 2:0:0:0:Direct-Access TOSHIBA TransMemory PMAP PQ: 0 ANSI: 4

sd 2:0:0:0: [sda]30489408 512-byte logical blocks: (15.6 GB/14.5 GiB)

sd 2:0:0:0: [sda]Write Protect is off

sd 2:0:0:0: [sda]No Caching mode page found

sd 2:0:0:0: [sda]Assuming drive cache: write through

sd 2:0:0:0: [sda]No Caching mode page found

sd 2:0:0:0: [sda]Assuming drive cache: write through

sda: sda1

sd 2:0:0:0: [sda]No Caching mode page found

sd 2:0:0:0: [sda]Assuming drive cache: write through

sd 2:0:0:0: [sda]Attached SCSI removable disk

usb 1-1: USBdisconnect, device number 4

wait otg vbuschange timeout!



USB在host模式时，才需要对外输出电源。slave mode时，不需要输出电源，但也不影响工作。

电源管脚：

IMX_GPIO_NR(4, 15),111

/test/gpio_set.sh111 0 //关pwr

实测不影响工作。其实，我觉得USB_ID和USB_VBUS就没什么关系。