DocID026411 Rev 2

13/26

AN4503

Linux kernel space

26

3.1.2

I²C_board_info structure patch

static struct i2c_board_info __inidata panda_i2c_memsensors[] = {

{

I2C_BOARD_INFO("lps25h", 0x5d),

.platform_data = & lps25h_platform,

},

{

I2C_BOARD_INFO("hts221", 0x5f),

.platform_data = & hts221_platform,

},

{

I2C_BOARD_INFO("uvis25", 0x47),

.platform_data = & uvis25_platform,

}

}

3.1.3

As an example of platform_data

static struct hts221_platform_data hts221_platform = {

.poll_interval = 1000,

.min_interval = 100,

}

A structure with the same name is also in the hts221.h file for compiling the module driver of

the corresponding device, included in [KR]/include/linux/input.

3.1.4

After rebuilding the kernel

Copy the new built zImage in the proper [RAS]/device/ti/panda/ folder as 'kernel' and then

rebuild the boot.img.

 [KR]$ cp -a arch/arm/boot/zImage $ANDROID_ROOT/device/ti/panda/kernel

 [RAS]$ make bootimage

3.2

Driver description

The device drivers are the first interface with the hardware; they communicate directly with

the sensor via the i2c bus. There are two files for each driver: the .c and the .h files.

3.2.1

How to build and install the device drivers

To build the proper device drivers, the .c files must be placed in the <KR>/drivers/misc

folder, while the corresponding .h files must be put in <KR>/include/lilnux/input.

If the drives are compiled as separate modules, the following example demonstrates the

lines to be added to the Makefile under <KR>/drivers/misc:

 obj-m = hts221.o

 obj-m + = lps25.o

 obj-m + = uv.ko