How to write a device driver in such a fashion .????

How to write a device driver in such a fashion .????

[Misbah khan]

Hi all ....

I need your suggession to write a driver with such requirements :-

On Initiation by the application of which key is pressed driver should
perform the task accordingly. There are 7 keys so seven different task the
driver will perform. 

1 . I do not want to use any entry point such as read/write/ioctl. In such a
case how to access the driver.
2. We dont want to implement this as a chracrter driver.
3. The driver shall look pretty much like an application where in asscssing
the H/W memory map .

Hence no entry point and no registeration but an application could be able
to communicate ....

I need your suggession in this regard .....

-----Misbah  
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RE: How to write a device driver in such a fashion .????

[Jenkins, Clive]

=20
> On Initiation by the application of which key is pressed
> driver should perform the task accordingly. There are 7
> keys so seven different task the driver will perform.=20

This is not clear to me.

> 1 . I do not want to use any entry point such as
> read/write/ioctl. In such a case how to access the driver.
> 2. We dont want to implement this as a chracrter driver.
> 3. The driver shall look pretty much like an application
> where in asscssing the H/W memory map .
>
> Hence no entry point and no registeration but an
> application could be able to communicate ....

I think you want the application to directly access
memory-mapped hardware. For this you will need to open
/dev/mem and use the mmap() system call to get a virtual
address of your h/w.

Clive

Re: How to write a device driver in such a fashion .????

[Misbah khan]

using mmap() in application to access the h/w is only possible if  the device
memory is mapped in the kernel virtual memory how come we directly map to
the physical memory to virtual from user space ??? 

----Misbah 

Misbah khan wrote:
> 
> Hi all ....
> 
> I need your suggession to write a driver with such requirements :-
> 
> On Initiation by the application of which key is pressed driver should
> perform the task accordingly. There are 7 keys so seven different task the
> driver will perform. 
> 
> 1 . I do not want to use any entry point such as read/write/ioctl. In such
> a case how to access the driver.
> 2. We dont want to implement this as a chracrter driver.
> 3. The driver shall look pretty much like an application where in
> asscssing the H/W memory map .
> 
> Hence no entry point and no registeration but an application could be able
> to communicate ....
> 
> I need your suggession in this regard .....
> 
> -----Misbah  
> 

-- 
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Re: How to write a device driver in such a fashion .????

[Scott Wood]

On Mon, Jan 07, 2008 at 08:31:10PM -0800, Misbah khan wrote:
> 
> using mmap() in application to access the h/w is only possible if  the device
> memory is mapped in the kernel virtual memory how come we directly map to
> the physical memory to virtual from user space ??? 

No, /dev/mem takes physical addresses, not kernel virtual.

-Scott