[SOLVED] device_create

sindhu4sind · 05-25-2012, 05:10 AM

I am using 2 different versions of ubuntu the kernel versions for both are:
1. Ubuntu 8.04 - kernel version is 2.6.24-26-generic
2. Ubuntu 10.04 - kernel version is 2.6.32-40-generic

I don't know why! but when i use this function in Ubuntu 10.04 it works fine but while i use same function, even same program in Ubunut 8.04 it gives me a warning

Quote:

WARNING: too many arguments for format

I am using device_create function like this:

Code:

device_create(my_class, NULL, MKDEV(major, 0), NULL, "my_dev");

I guess some defination of this function might be changed!! can anyone please suggest me correct defination??

Thanks for always good response from you guys of newbie forum at LinuxQustions.org..
sindhu..

Aquarius_Girl · 05-25-2012, 07:56 AM

I gave you the link of "Linux Kernel API" in your previous thread.
http://gnugeneration.com/books/linux/2.6.20/kernel-api/

sindhu4sind · 05-25-2012, 11:31 AM

Quote:

Originally Posted by Anisha Kaul

I gave you the link of "Linux Kernel API" in your previous thread.
http://gnugeneration.com/books/linux/2.6.20/kernel-api/

Thank you Anisha Kaul...

Yes, I also had a look at device.h file in 2.6.24:
I found syntax like:

Code:

extern struct device *device_create(struct class *cls, struct device * parent, dev_t devt, const char *fmt, ...)

I have changed the line of code according to format can u please check it:

Code:

device_create(my_class, NULL, MKDEV(major, 0), "my_dev");

now there's no warning, but its also not creating device or file "/dev/my_dev"

May be my syntax is not correct, can you please correct it if it has some mistake?
Thanks for your response
Sindhu

Aquarius_Girl · 05-25-2012, 01:41 PM

Have you cross checked the major and minor numbers used in MKDEV?

sindhu4sind · 05-26-2012, 03:10 AM

Quote:

Originally Posted by Anisha Kaul

Have you cross checked the major and minor numbers used in MKDEV?

Thank you Anisha Kaul,

I got a solution.. Here I am sharing for helping others.. May be I am the only one who's facing such kind of issues because not very well known of C language and kernel programming.. but what ever, i love to share my solutions:

I have re-defined the device_create parameters if the kernel version is above than 2.6.15, like this:

Code:

#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,15)
    #define my_device_create(a, b, c, d) device_create(a, b, c, NULL, d)
#else
    #define my_device_create(a, b, c, d) device_create(a, b, c, d)
#endif

It worked for me..

Thanks for response..

Sindhu