usb slave driver issue

Rain Peng

now I met a problem:

I have a customize board based on DM6467, I want to stream video out to windows PC via usb port. so I made the following changes in the board kernel:

Kernel config for Gadget Serial Driver

[Linux Kernel Configuration] -→ [Device Drivers] -→ [USB support] -→ [USB Gadget Support]

<M> Support for USB Gadgets
<M>   Serial Gadget (with CDC ACM support)

then I load the gadget serial driver using command :

root@dm6467-evm:/opt/usb# insmod g_serial.ko use_acm=1
g_serial gadget: Gadget Serial v2.4
g_serial gadget: g_serial ready

root@dm6467-evm:/opt/usb# ls /dev/ttyGS0 -l
crw-rw---- 1 root dialout 250, 0 Jan 12 23:29 /dev/ttyGS0

normally,when the gadget serial driver is loaded and the USB device connected to the Windows host with a USB cable, Windows should recognize

the gadget serial device and ask for a driver. but actually,my PC had no reflection.

can anybody help me?

I already have files “gserial.inf” and “usbser.sys”.

the D- and D+ pins of USB port (B type) are connected to DN(A20) and DP(A19) pins of 6467.

over 15 years ago

0 Rain Peng over 15 years ago

Intellectual 620 points

I got it working,the board can communicate with PC via usb port,but I consider the speed of serial transmission over usb maynot feed the speed of video data transmission。

I want to stream HD video(720P) from board to windowsPC via USB port, how can I do?

0 Zegeye Alemu over 15 years ago in reply to Rain Peng

TI__Expert 5475 points

Hi,

From USB perspective Video traffic is catagorized as an Isochronous type where the importance of the transfer attribute is focused on timely delivery as opposed to data integrity.

The DM6467 device supports Isochronous transfer and max packet size for this transfer in High Speed mode is 1024 Bytes per micro-frame. If you schedule a transfer to happen every micro-frame it will handle 1024Bytes/micro-sec * 8000 transfer = 8MBytes/Sec.

Best regards, Zegeye

0 Zegeye Alemu over 15 years ago in reply to Zegeye Alemu

TI__Expert 5475 points

Hi,

Meant to say micro-frame not micro-sec. That is, the ISO Transfer size is 1024 Bytes/micro-frame not micro-sec. One micro-frame is 125micro-sec long.

Best regards, Zegeye

0 swami over 15 years ago in reply to Rain Peng

TI__Expert 7435 points

You would have to implement a UVC (usb Video Class) gadget or backport the same from the latest community kernel. Using UVC class api's you can stream the video data to the PC.

regards

swami

0 Rain Peng over 15 years ago in reply to swami

Intellectual 620 points

swami,

thanks for your reply. Now I use ethernet over usb, treat usb as ethernet, I can transmit HD video to PC via usb now.

Regards,

Rain

0 swami over 15 years ago in reply to Rain Peng

TI__Expert 7435 points

Are you streaming uncompress HD video over USB (as ethernet device) ? If so at what resolutions ? The reason I am asking this is to confirm that the ethernet type bandwidth (as you are emulating ethernet profile over usb) might restrict your peak bandwidth needs.

regards

swami

0 Brad Griffis over 15 years ago in reply to swami

TI__Guru*** 125430 points

He's streaming 8Mbps H.264.

0 Rain Peng over 15 years ago in reply to Brad Griffis

Intellectual 620 points

yes, it's TS fromat with h264 and aac codec

0 Anil Verma90370 over 14 years ago in reply to swami

Intellectual 735 points

Hi Swami,

I am using DM368 Soc,able to capture video and encode in mpeg2 as per my requirement. But I am not able to understand how to

stream video data to host PC through USB.everyone mansion use UVC class API but i am not able to find out uvc class based application.

Please provide your guidelines in this.

Regards,

Anil

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usb slave driver issue