On Tue, 28 Feb 2006, Thomas Seiler wrote: > Hello, > > I am trying to hack together USB Host support for Motorola EZX series > of linux based smartphones (like E680i, A780, A1200) and I am stuck > with device enumeration. (details see > http://www.seili.net/a780usb.php). These phones run a Montavista Linux > 2.4.17 with usbfs disabled on Intel PXA271. > > I can connect a device and the CCS (Current Connection Status) bit in > the Ports Root Hub register is beeing set, so I think I got the > physical things ok (resistors, multiplexing of GPIO function, etc...). > However, nothing happens afterwards. No messages in dmesg. Steady > signal (DC) on the oscilloscope. > > I am a USB newbie and a bit confused now. The docu I found was mainly > related to how to write a new USB device driver. > > * How exactly did a Linux 2.4.17 learn that a new device was connected > to a OHCI controller ? By Interrupt ?
No, it uses a kernel timer for polling. Read the rh_int_timer_do() and rh_send_irq() subroutines in usb_ohci.c. > * And how does the virtual root hub know how many ports there are and > where they are ? It gets the number of ports from the hardware during initialization. However, it does _not_ know where they are. > * Is there a way I can tell how many ports there are without usbfs ? If you turn on debugging (#define DEBUG near the start of the source file), the number of ports should be printed in the kernel's debugging log. Alternatively, you can turn on CONFIG_USB_DEBUG in the kernel configuration; then the hub driver will print a lot of information in the kernel log. > * Or if a new device was connected again without usbfs ? With debugging turned on, messages will appear in the kernel log. Alan Stern ------------------------------------------------------- This SF.Net email is sponsored by xPML, a groundbreaking scripting language that extends applications into web and mobile media. Attend the live webcast and join the prime developer group breaking into this new coding territory! http://sel.as-us.falkag.net/sel?cmd=lnk&kid=110944&bid=241720&dat=121642 _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
