On Wed, 27 Aug 2008 10:20:58 -0400 "mike zheng" mail4mz@gmail.com wrote:
I am using an embedded system with MPC8567 as processor and ISP1561 as USB PCI host controller. There is USB port on this board. A sealevel USB/RS232 cable is connect to the USB port on the board, and it converts USB port into RS232 port. A PC is connected to the RS232 end of the cable.
With "CONFIG_USB_SERIAL_FTDI_SIO" flag enabled, I compiled the Linux kernel. Everything works fine, I am able to launch the hyperterminal on PC and have the console running for Linux.
Now I need make things working for Uboot. I've already have the EHCI host controller running well on the board.
Please correct me if my understanding is incorrect. What I need to do is to port the FTDI_SIO driver from Linux to Uboot, which replace those "udc" calls in usbtty.c. With the ported FTDI_SIO code and existing usbtty.c. It shall work fine after correct setup of the environment variables - "setenv stdin usbtty, setenv stdout usbtty".
That really depends on what you mean by "replace".
usbtty at this moment in time is slave only. What you are describing is having u-boot be a USB host, and control a usbserial device attached to the u-boot/host.
usbtty - is basically analogous to the firmware that would run inside of your USB-2-RS232 cable, in that it - uboot- is a USB slave, at the usbtty layer.
Not that I've looked in detail but, whatever way USB sticks are controlled by USB hosts in u-boot would be closer to what you'd need to do to support having a USB-slave tty device attached to your board, then subsequently you'd plug this into the serial layer of u-boot.
Possibly you could add the usbserial and cdc-acm protocols supported in usbtty.. depending .. but, it's important to be aware that usbtty in u-boot is a slave oriented thing.
For the case above - you'd need to implement drivers/usbdcore_isp1561.c - but .. this would have to be a USB host... not a slave.
Since a USB host model already exists in u-boot - I'm not sure making usbdcore_isp1561.c would be a wise or acceptable choice.
For example usbdcore_mpc8xx.c and it's sibling usbdcore_omap1510.c - enumerate a USB host... - they're completely slave oriented... whereas - you need for u-boot to be the host like drivers/usb/isp116x-hcd.c (perhaps a isp1516-hcd.c is required), then you need to plug your FTDI stuff on top of that, then you need to plug that into the u-boot serial layer, somehow...
Sure it might be possible and appropriate to have [usbtty.c=>fdti]=>isp1516-hdc.c but, the low-level USB twiddling you need to do at the host controller level will be quite different for the host - which is what I think you need to do... in comparison to the slave - which is what usbdcore_mpc8xx.c and usbdcore_omap1510.c are.
Greetings, Bryan