okay, let me in detail tell you whatever my understanding is: register_chrdev: register_chrdev(major, name, fops) - here we specify that this is my device-driver name, the major number for it and fops pointer. (that is the device related functions to read/write.open/close the device). so whenever kernel sees any device read/write request, it will look for the driver with matching major number and that is how it will select which function to call. what i want to know is in the drivers read method , we will read data from the device memory and copy it to the buffer in user area. using function copy_to_user( user-buf-pointer, device-data-ptr, count) where do i get the "device-data-ptr" from? i'm very sorry if my question is too silly!! thanks for ur reply! > -----Original Message----- > From: karthick.sundararajan@xxxxxxxxx > [mailto:karthick.sundararajan@xxxxxxxxx] > Sent: Thursday, February 17, 2005 11:06 AM > To: kernelnewbies@xxxxxxxxxxxx; Dhanashri Bhate > Subject: RE: Basic question about device driver > > > > Hi Dhanshri, > > Can you be a bit more specific about the question: I am not able to > understand if you are asking about how register_chrdev works > or just the > usage of register_chrdev. > > Rgds, > Karthick S. > > > -----Original Message----- > From: kernelnewbies-bounce@xxxxxxxxxxxx > [mailto:kernelnewbies-bounce@xxxxxxxxxxxx] On Behalf Of > Dhanashri Bhate > Sent: Thursday, February 17, 2005 10:42 > To: kernelnewbies@xxxxxxxxxxxx > Subject: Basic question about device driver > > > hi, > i know unix fairly well and good at C, but new to the linux > environment. > I'm studying device driver development(kernel space). i'm refering the > linux device driver book by allessandro rubini. which is > quite good... > but still i'm having some problems in thoroghly understanding > the basic > concepts! > > someone pls answer this: how exactly a device address comes to the > driver? ( which will be used by copy-to-user/copy-from-user) > > > Thanks, > Dhanshri > > > > > > -- > Kernelnewbies: Help each other learn about the Linux kernel. > Archive: http://mail.nl.linux.org/kernelnewbies/ > FAQ: http://kernelnewbies.org/faq/ > > > > Confidentiality Notice > > > The information contained in this electronic message and any > attachments to this message are intended > for the exclusive use of the addressee(s) and may contain > confidential or privileged information. If > you are not the intended recipient, please notify the sender > at Wipro or Mailadmin@xxxxxxxxx immediately > and destroy all copies of this message and any attachments. > -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
