Adding new driver code to linux source code

Question

I have developed a Linux device driver. As of now I am compiling it on Ubuntu 12.04 with cross-compiler for arm and then insmoding it in my arm Linux image. But I want to learn how I can add it in Linux source code and give and option to add/remove through configuration of arm Linux, so that I can compile it with Linux source code compilation?

Any ideas?

Answer 1

To cross compile your own driver in the arm architecture you have to follow some steps as mentioned below.

1. Create a directory like my_drvr inside drivers(which is in the Linux source code) for your driver and put your driver (my_driver.c) file inside this directory. It will looks like /linux_source_code/drivers/my_drvr/my_driver.c

2. Create one Makefile inside your driver directory (using vi any editor) and inside this put obj-$(CONFIG_MY_DRIVER) += my_driver.o and save this file. This will appears like /linux_source_code/drivers/my_drvr/Makefile

3. Create one Kconfig file inside your driver directory (using vi any editor) and inside this put

   config MY_DRIVER
   tristate "my driver" //gives your driver description like vendor name etc.
   depends on ARM
   default y if ARM
   help
     my driver module.

4. Save this file, this will appears like /linux_source_code/drivers/my_drvr/Kconfig

5. Add both Makefile and Kconfig file in the Linux source drivers Makefile and Kconfig file which are at /linux_source_code/drivers/Makefile and /linux_source_code/drivers/Kconfig

6. In the Makefile add below in last line

    obj-y    += my_drvr/ 

   or

    obj-$(CONFIG_MY_DRIVER)   += my_drvr/

7. In Kconfig file add below in last line

   source "drivers/my_drvr/Kconfig"

8. Finally have to add Kconfig file into architecture specific config file which will be at kernel_source/arch/arm/configs/--defconfig in this add below line in the last

   CONFIG_MY_DRIVER=y

Note:- Last step will differ according to your architecture, so that you have take care. Now you can compile your driver by using make command. (eg: sun7i_defconfig)