Difference between revisions of "Linux drivers development"
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Our custom drivers build is integrated to the Linux build system (kbuild). | Our custom drivers build is integrated to the Linux build system (kbuild). | ||
| − | You can select, in the linux "menuconfig | + | You can select, in the linux "menuconfig / xconfig" tool, which Armadeus drivers you want to add on your target. |
| − | drivers you want to add on your target. | + | $ make linux26-menuconfig |
| − | + | ||
Here is the way to add custom drivers: | Here is the way to add custom drivers: | ||
| − | * in armadeus/target/linux/modules/, add a directory for you driver (ex toto/) | + | * in ''armadeus/target/linux/modules/'', add a directory for you driver (ex ''toto/'') |
| − | * put reference to this directory in the armadeus/target/linux/modules/Makefile and armadeus/target/linux/modules/Kconfig files | + | * put reference to this directory in the ''armadeus/target/linux/modules/Makefile'' and ''armadeus/target/linux/modules/Kconfig'' files |
| − | * in toto/ put your driver source code and create 2 files, Kconfig and Makefile. (Use armadeus/target/linux/modules/gpio/Makefile & Kconfig as examples.) | + | * in ''toto/'' put your driver source code and create 2 files, ''Kconfig'' and ''Makefile''. (Use ''armadeus/target/linux/modules/gpio/Makefile'' & ''Kconfig'' as examples.) |
| − | To compile the modules, either launch: | + | To compile all the custom modules, either launch: |
| − | + | $ make -C armadeus/target/linux/modules/ | |
or | or | ||
| − | + | $ make linux26 | |
| − | only | + | only ''make linux26'' will install the modules in target rootfs image |
== i.MX register access from driver == | == i.MX register access from driver == | ||
Revision as of 19:24, 16 December 2008
This page summarizes all you need to know before starting to develop Linux drivers for your Armadeus board
Contents
Recommended reading before starting
We advise you to read (not necessarly understand ;-) ):
- Linux Device Drivers (3rd edition) book: http://lwn.net/Kernel/LDD3/
Adding your own drivers
Our custom drivers build is integrated to the Linux build system (kbuild). You can select, in the linux "menuconfig / xconfig" tool, which Armadeus drivers you want to add on your target.
$ make linux26-menuconfig
Here is the way to add custom drivers:
- in armadeus/target/linux/modules/, add a directory for you driver (ex toto/)
- put reference to this directory in the armadeus/target/linux/modules/Makefile and armadeus/target/linux/modules/Kconfig files
- in toto/ put your driver source code and create 2 files, Kconfig and Makefile. (Use armadeus/target/linux/modules/gpio/Makefile & Kconfig as examples.)
To compile all the custom modules, either launch:
$ make -C armadeus/target/linux/modules/
or
$ make linux26
only make linux26 will install the modules in target rootfs image
i.MX register access from driver
To access i.MX registers from your driver, please use the macros defined in:
#include <arch/arm/imx-regs.h>
For example (access to PWM control register):
//enable the PWM PWMC |= PWMC_EN;
Debug
Activate debug messages (from pr_debug() function) on console:
# echo 8 > /proc/sys/kernel/printk
