Hi . Its a data acquisition ssytem ... Requirement is like this..I have to work on arm omap arm processor with linux on it . I have to acquire data from some interfaces like UART and store that data through USB interface.OR read it from USB interface Now most probably it shd be a pendrive on usb connected to board . So i want to learn how can we store data on a pen drive connected to usb interface from use space C program. in that concern ..i reached to Greg K H article mentioning libusb ...is there any other way too ? then usb_control_msg function i found difficult to comprehend ..how do i know parameters for my pen drive .... =================================================================== Now another question ...related to basic concept ..... As i have practiced writing a few block device driver(but just on virtual memory not on acttual device ) and worked on filesystem code i was wondering .... If we have a pendrive acting as a block device with lets say fat32 on it . Then how do we interact with it through USb driver or through block device driver I am trying to understand ...they should be on different layers ... Filesystem sends data to block device layer ...and after processing ... a block of data finally coming out of kernel block device driver ..... to be written to specified block device ...which acc to kernel is a file /dev/hda lets say then where does usb driver fits ..in this picture Nidhi On Thu, Nov 18, 2010 at 11:24 AM, Greg KH <greg@xxxxxxxxx> wrote: > On Thu, Nov 18, 2010 at 11:00:13AM +0530, nidhi mittal hada wrote: >> Hi all >> >> i am learning how to communicate to usb interface in linux from user sspace in C >> >> I have read usb in nutshell and greg K H article in linux journal . >> >> I am working on simple data acquisitioon system .. which has to >> read/store data on usb ... >> >> I read from Greg's article that i need to use libusb for this purpose . >> >> Now i am stuck at usb_control_msg() and parameters to be passed in it . >> >> as i am not able to understand how to decide what should be value of >> parameters for normal pendrive with me .... > > A pendrive is one of the most complex USB devices out there, you will > not be successful in writing a tiny driver to talk to it (it's really > SCSI over USB). ÂBecides we already have 2 drivers in the tree already > to control this device, why do you need/want another one? > > First off, what specifically do you want to do here, and why do you want > to do it (i.e. the root problem you are trying to solve.) > > thanks, > > greg k-h > -- Thanks & Regards Nidhi Mittal Hada Scientific officer D Computer Division Bhabha Atomic Research Center Mumbai http://nidhi-searchingmyself.blogspot.com/ -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
