how can I read from a char device?

[a_n_h]

Hi there,

how are you doing?

I am writing a simple char device that generates pseudo-random numbers, the problem is that I cant seem to figure out how to test it, i tired using "cat /dev/(device's name)" but all i get is an infinite loop, though that happens as well when i use cat on other devices in the /dev dictionary.

anyone can help me out please?

here is the code of my read function of my device

ssize_t read(struct file *file, char __user *buf, size_t len, loff_t *offset)
{
         ssize_t ret = 0;
         if(copy_to_user(buf, (int)rg_hw(), (int)len))
         {
                   return -EFUALT;
         }

         return ret;
}

unsigned char rg_hw()
{
        random_seed = random_seed * 32423423 + 12324;
        return (unsigned char)((unsigned int)(random_seed /234234) % 256);
}

thank you in advance!

EDIT: upon further testing i think the problem is with my read function, i think i misused copy_to_user. but i dont whats wrong with it, any ideas

[Rubberman]

Questions about kernel programming issues should be posted to The Linux Kernel forum. Please move your question there.