TCA 8418 I2C Communication

I do not have this EVM. I am guessing that your board file needs TCA8418 platform data definition. Is the driver compiled with the kernel or as a loadable module? The device file might not be in /dev/input. Look around in /dev for any tca8418 directories.

Hi...

      Thank you for kind responsble answer...

     This TCA8418 driver is loaded as a module to kernel 3.2.0. It is ported after cross compiling to am335x process eventhought event is not found in /dev directory.This am335x i2c is communicating throught  I2C_2 SDA,SCL lines.

    I found in my /dev dirctory only I2c_1 and I2c_3 lines but not I2c_2 .

    How to enable i2c_2  line ?

With Regards

Tamilarasi

The i2c1 and i2c3 are probably configured in your board file. It should be a file in arch/arm/mach-omap2. Look for the ".o" file to see which one was compiled in. Look in your specific board.c to see how i2c1 and i2c3 are setup. Take care to check for pinmux conflicts.

Loading the TCA8418 module as a loadable module might not work. Usually code in the board.c file adds the i2c device into the i2c core driver. The TCA8418 probably is not written to add itself.

Hi...

      I am trying to interface TCA8418 keyboard with am335x processor throught I2C communication.So I have cross compiled the TI kernel version 3.2.0 for arago toolchain. 

      Now I2C_3 line is working fine to communicate board with processor. Eventhought TCA8418 driver added as a module, Compilation has done throught procedure.

     The problem is event could not occur in beaglebone kernel /dev dirctory.

    Is there any other procedure to compile kernel with TCA8418 (or) which kernel would be support for am335x along with tca8418

driver?

  By checking cat /proc/interrupts  I2C interrupts has incremented when i2cdump 3 0x34 is executed

  This is my cross compiled u-boot and kernel

U-Boot SPL 2011.09 (Jul 19 2012 - 10:21:52)
Texas Instruments Revision detection unimplemented
No AC power, disabling frequency switch
OMAP SD/MMC: 0
reading u-boot.img
reading u-boot.img


U-Boot 2011.09 (Jul 19 2012 - 10:21:52)

I2C:   ready
DRAM:  256 MiB
WARNING: Caches not enabled
No daughter card present
NAND:  HW ECC Hamming Code selected
nand_get_flash_type: second ID read did not match 10,10 against 00,00
No NAND device found!!!
0 MiB
MMC:   OMAP SD/MMC: 0, OMAP SD/MMC: 1
*** Warning - readenv() failed, using default environment

Net:   cpsw
Hit any key to stop autoboot:  0
SD/MMC found on device 0
reading uEnv.txt

33 bytes read
Loaded environment from uEnv.txt
Importing environment from mmc ...
reading uImage

3040712 bytes read
## Booting kernel from Legacy Image at 80007fc0 ...
   Image Name:   Linux-3.2.0
   Image Type:   ARM Linux Kernel Image (uncompressed)
   Data Size:    3040648 Bytes = 2.9 MiB
   Load Address: 80008000
   Entry Point:  80008000
   Verifying Checksum ... OK
   XIP Kernel Image ... OK
OK

Starting kernel ...

Uncompressing Linux... done, booting the kernel.
[    0.155090] tps65910 1-002d: could not be detected
[    0.207794] Could not set LED4 to fully on
[    0.911102] mtdoops: mtd device (mtddev=name/number) must be supplied
[    1.017120] omap_hwmod: wkup_m3: wkup_m3: hwmod data error: OMAP4 does not support st_shift
[   15.601654]
[   15.601654] CPSW phy found : id is : 0x7c0f1
[   15.608459] PHY 0:01 not found

.---O---.                                           
|       |                  .-.           o o        
|   |   |-----.-----.-----.| |   .----..-----.-----.
|       |     | __  |  ---'| '--.|  .-'|     |     |
|   |   |  |  |     |---  ||  --'|  |  |  '  | | | |
'---'---'--'--'--.  |-----''----''--'  '-----'-'-'-'
                -'  |
                '---'

The Angstrom Distribution beaglebone ttyO0

Angstrom v2012.01-core - Kernel 3.2.0

I have checked keyscan using i2c tool commands

i2cdetect -r 3
device ID selected

Before executing  i2cdump 3 0x34(i2cdump  i2cline  device Id)

cat /proc/interrupts

 CPU0      
 12:       2634      INTC  edma
 14:          0      INTC  edma_error
 18:         41      INTC  musb-hdrc.0
 19:          1      INTC  musb-hdrc.1
 30:       3272      INTC  omap_i2c
 40:          0      INTC  cpsw.0
 43:          0      INTC  cpsw.0
 64:       8074      INTC  mmc0
 68:       5872      INTC  gp timer
 70:        143      INTC  omap_i2c
 72:       1664      INTC  OMAP UART0
 75:          0      INTC  rtc0
 76:          0      INTC  rtc0
 77:          0      INTC  wkup_m3
 78:          1      INTC  wkup_m3_txev
 93:        576      INTC  cpsw.0
 94:        101      INTC  cpsw.0
166:          0      GPIO  mmc0
Err:          0



i2cdump 3 0x34

 0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f    0123456789abcdef
00: c4 ff 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ?...............
10: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
20: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 XX    ...............X
30: c4 c4 c4 c4 c4 c4 c4 c4 c4 c4 c4 c4 c4 c4 c4 XX    ???????????????X
40: c4 ff 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ?...............
50: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
60: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 XX    ...............X
70: c4 c4 c4 c4 c4 c4 c4 c4 c4 c4 c4 c4 c4 c4 c4 XX    ???????????????X
80: c4 ff 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ?...............
90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 XX    ...............X
b0: c4 c4 c4 c4 c4 c4 c4 c4 c4 c4 c4 c4 c4 c4 c4 XX    ???????????????X
c0: c4 ff 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ?...............
d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 XX    ...............X
f0: c4 c4 c4 c4 c4 c4 c4 c4 c4 c4 c4 c4 c4 c4 c4 XX    ???????????????X

Atter Executing  i2cdump 3 0x34

cat /proc/interrupts

           CPU0      
 12:       2640      INTC  edma
 14:          0      INTC  edma_error
 18:         41      INTC  musb-hdrc.0
 19:          1      INTC  musb-hdrc.1
 30:       4280      INTC  omap_i2c
 40:          0      INTC  cpsw.0
 43:          0      INTC  cpsw.0
 64:       8104      INTC  mmc0
 68:       6644      INTC  gp timer
 70:        143      INTC  omap_i2c
 72:       2042      INTC  OMAP UART0
 75:          0      INTC  rtc0
 76:          0      INTC  rtc0
 77:          0      INTC  wkup_m3
 78:          1      INTC  wkup_m3_txev
 93:        634      INTC  cpsw.0
 94:        111      INTC  cpsw.0
166:          0      GPIO  mmc0
Err:          0

    Kindly give me solution to this problem.

   With Regards.

   Senthamilarasi

Looks like you have managed to hook up your I2C device to i2c3 and you are talking to it. You could just talk to it using i2c but I asusme that you want to use the input interface. I am not sure what you have done so far in the kernel. The 3.2 kernel does not have the TCA8418 driver but later kernels have it. To port over the driver, the following files need to be changed.

File:include/linux/input/tca8418_keypad.h
Get from kernel.org or arago
http://arago-project.org/git/projects/?p=linux-davinci.git;a=blob_plain;f=include/linux/input/tca8418_keypad.h;hb=HEAD

File:drivers/input/keyboard/tca8418_keypad.c
Get from kernel.org or arago
http://arago-project.org/git/projects/?p=linux-davinci.git;a=blob_plain;f=drivers/input/keyboard/tca8418_keypad.c;hb=HEAD

File:drivers/input/keyboard/Makefile
obj-$(CONFIG_KEYBOARD_TCA6416)        += tca6416-keypad.o
obj-$(CONFIG_KEYBOARD_TCA8418)        += tca8418_keypad.o
obj-$(CONFIG_KEYBOARD_HIL)        += hil_kbd.o

File: drivers/input/keyboard/Kconfig
config KEYBOARD_TCA6416
    tristate "TCA6416/TCA6408A Keypad Support"
    depends on I2C
    help
      This driver implements basic keypad functionality
      for keys connected through TCA6416/TCA6408A IO expanders.

      Say Y here if your device has keys connected to
      TCA6416/TCA6408A IO expander. Your board-specific setup logic
      must also provide pin-mask details(of which TCA6416 pins
      are used for keypad).

      If enabled the entire TCA6416 device will be managed through
      this driver.

      To compile this driver as a module, choose M here: the
      module will be called tca6416_keypad.

config KEYBOARD_TCA8418
    tristate "TCA8418 Keypad Support"
    depends on I2C
    help
      This driver implements basic keypad functionality
      for keys connected through TCA8418 keypad decoder.

      Say Y here if your device has keys connected to
      TCA8418 keypad decoder.

      If enabled the complete TCA8418 device will be managed through
      this driver.

      To compile this driver as a module, choose M here: the
      module will be called tca8418_keypad.

config KEYBOARD_MATRIX

File:arch/arm/configs/am335x_evm_defconfig
# CONFIG_KEYBOARD_TCA6416 is not set
CONFIG_KEYBOARD_TCA8418=y
CONFIG_KEYBOARD_MATRIX=y

File:arch/arm/mach-omap2/board-am3517evm.c
A platform device needs to be added. I cannot find an example for this. You might want to contact the writer of the driver code. You might be able to guess it by looking at examples of other I2C keypad code on other boards.

Hi ....

     Thank you for valuable answer...

  As per your advice  have modified everthing in kernel  regarding TCA8418 driver, Except below mentioned file because it's already  existed in kernel as  board-am335xevm.c

File:arch/arm/mach-omap2/board-am33xevm.c   so i didn't change anything.(i am using am3359 beaglebone processor)

So i cross compiled compiled the kernel using the  following steps

step 1: export PATH=~/am335x/ti-sdk-am335x-evm-05.04.01.00/linux-devkit/bin:$PATH

step 2: export ARCH=arm

step 3:export CROSS_COMPILE=arm-arago-linux-gnueabi-

step 4:make ARCH=arm am335x_evm_defconfig

step 5 :make menuconfig ====> here is enabled TCA8418 driver and i2c support modules(as predefined using *)

step 6: make uImage

Finally i got uImage in arch/arm/boot/uImage

Then i ported this uImage to SDcard along with TI u-boot and MLO, Board is booted well.

Eventhought i didn't get Event around /dev and /dev/input  directory,

 I2c communication is enabled and working fine.

Note: I tried latest kernel 3.4.7 but here board-am335xevm.c support is not existed .

Unable to find the problem in this kernel, Any other solution please (or) Any configuration needs for TCA8418  registers and am335x board.

With Regards.

M.senthamilarasi

The board file absolutely needs to modified to startup the driver. You will not get any event devices until then. There are also other questions of how to specify an GPIO IRQ for asynchronous notification. Might be that the driver uses polling. I suggest you e-mail the driver writer.

Sorry about pointing you to the wrong board file. My error.

Hi..

   Thank you very much for your respose

Now i understood the problem is in am335x board file, Needs in include platform data definitions about the TCA8418 device.

Can you suggest me how to add platform data definitions to board file, Becase i am new this beaglebone environment and i have e-mailed to  the driver writter.

=>kernel version 3.2.0

=>board file is board-am335xevm.c

 =>i2c line  i2c_3

If you have any idea of platform definitions please help me to this project.

With Regards..

Senthamilarasi

I can only make some guesses at what the structure initializations should be in your board.c file. No guarantees.

File: arch/arm/mach-omap2/board-am335xevm.c

...
#include <linux/input/tca8418_keypad.h>
...
/* KEY(row, col, val) */
static uint32_t tca8418_km_data[] = {
    KEY(0, 0, KEY_LEFT),
    KEY(0, 1, KEY_DOWN),
    KEY(0, 2, KEY_ENTER),
    KEY(0, 3, KEY_M),

    KEY(1, 0, KEY_RIGHT),
    KEY(1, 1, KEY_UP),
    KEY(1, 2, KEY_I),
    KEY(1, 3, KEY_N),

    KEY(2, 0, KEY_A),
    KEY(2, 1, KEY_E),
    KEY(2, 2, KEY_J),
    KEY(2, 3, KEY_O),

    KEY(3, 0, KEY_B),
    KEY(3, 1, KEY_F),
    KEY(3, 2, KEY_K),
    KEY(3, 3, KEY_P)
};

static const struct matrix_keymap_data tca8418_mkdata[] = {
    .keymap            = tca8418_km_data,
    .keymap_size        = ARRAY_SIZE(tca8418_km_data),
};

static struct tca8418_keypad_platform_data tca8418_pdata = {
    .keymap_data = &tca8418_mkdata;
    .rows = 4;
    .cols = 4;
    .rep = 1;         /* Just a guess */
    .irq_is_gpio = 0; /* Just a guess */
};

static struct i2c_board_info am335x_i2c_boardinfo2[] = {
    {
        I2C_BOARD_INFO(TCA8418_NAME, TCA8418_I2C_ADDR),
        .platform_data = &tca8418_pdata,
    },
};
...

Search around in your kernel source for usage of the matrix_keymap_data structure. There are a lot of examples.

Hi Norman Wong

                i was on leave around one month so that unable continue my work. Recently i started my keyboard work.

  I have added below platform data with my board file board-am335xevm.c

       static struct tca8418_keypad_platform_data am335x_tca8418_info = {
        .keymap_data = &am335x_evm_keymap_data,
        .rows=8,
        .cols=10,
        .rep=0,
        .irq_is_gpio=0,

   };

      {
               I2C_BOARD_INFO("tca8418_keypad", 0x34),
                .platform_data=&am335x_tca8418_info,
        },

==>After compilation of this kernel, I have ported this uImage to the board.

==>Now i am getting event0 on /dev/input/event0 and /sys/class/input/event0 but keys are not detected from tca8418 board.

==>After porting this image donot connect the TCA8418 keyboard to the beaglebone but event0 is existed.

==>By using I2c tools can be accessed the keyboard, So i confomed that keyboard is working fine, and it has been set as keypad mode.

I posted Boot log and dmesg please help us to solve this problem.

root@beaglebone:~# ls /dev/input
by-path  event0  mice

root@beaglebone:~# ls /sys/class/input/
event0  input0  mice

Boot log

Starting kernel ...

Uncompressing Linux... done, booting the kernel.
[    0.155273] tps65910 1-002d: could not be detected
[    1.168151] omap_i2c omap_i2c.3: controller timed out
[    1.188140] tps65910 3-002d: could not be detected
[    1.241302] Could not set LED4 to fully on
[    2.242340] omap_i2c omap_i2c.3: controller timed out
[    2.242401] Could not set LED4 to fully on
[    2.380340] kobject_add_internal failed for omap_i2c.3 with -EEXIST, don't try to register things with the .
[    2.394897] omap_device: omap_i2c: build failed (-17)
[    2.524475] mtdoops: mtd device (mtddev=name/number) must be supplied
[    2.606231] omap_hwmod: wkup_m3: wkup_m3: hwmod data error: OMAP4 does not support st_shift
Failed to mount /sys/kernel/security: No such file or directory

.---O---.                                           
|       |                  .-.           o o        
|   |   |-----.-----.-----.| |   .----..-----.-----.
|       |     | __  |  ---'| '--.|  .-'|     |     |
|   |   |  |  |     |---  ||  --'|  |  |  '  | | | |
'---'---'--'--'--.  |-----''----''--'  '-----'-'-'-'
                -'  |
                '---'

The Angstrom Distribution beaglebone ttyO0

Angstrom v2012.03-core - Kernel 3.2.0

dmesg | grep tca8418

[    0.155639] tca8418 keyscan key probe
[    0.156219] input: tca8418_keypad as /devices/platform/omap/omap_i2c.1/i2c-1/1-0034/input/input0

dmesg

[    0.000000] Linux version 3.2.0 (arasi@arasi) (gcc version 4.5.3 20110311 (prerelease) (GCC) ) #2 Fri Sep 12
[    0.000000] CPU: ARMv7 Processor [413fc082] revision 2 (ARMv7), cr=10c53c7d
[    0.000000] CPU: PIPT / VIPT nonaliasing data cache, VIPT aliasing instruction cache
[    0.000000] Machine: am335xevm
[    0.000000] Memory policy: ECC disabled, Data cache writeback
[    0.000000] On node 0 totalpages: 65536
[    0.000000] free_area_init_node: node 0, pgdat c065545c, node_mem_map c068c000
[    0.000000]   Normal zone: 512 pages used for memmap
[    0.000000]   Normal zone: 0 pages reserved
[    0.000000]   Normal zone: 65024 pages, LIFO batch:15
[    0.000000] AM335X ES1.0 (sgx neon )
[    0.000000] pcpu-alloc: s0 r0 d32768 u32768 alloc=1*32768
[    0.000000] pcpu-alloc: [0] 0
[    0.000000] Built 1 zonelists in Zone order, mobility grouping on.  Total pages: 65024
[    0.000000] Kernel command line: console=ttyO0,115200n8 run_hardware_tests quiet root=/dev/mmcblk0p2 rw rooe
[    0.000000] PID hash table entries: 1024 (order: 0, 4096 bytes)
[    0.000000] Dentry cache hash table entries: 32768 (order: 5, 131072 bytes)
[    0.000000] Inode-cache hash table entries: 16384 (order: 4, 65536 bytes)
[    0.000000] Memory: 256MB = 256MB total
[    0.000000] Memory: 253152k/253152k available, 8992k reserved, 0K highmem
[    0.000000] Virtual kernel memory layout:
[    0.000000]     vector  : 0xffff0000 - 0xffff1000   (   4 kB)
[    0.000000]     fixmap  : 0xfff00000 - 0xfffe0000   ( 896 kB)
[    0.000000]     vmalloc : 0xd0800000 - 0xff000000   ( 744 MB)
[    0.000000]     lowmem  : 0xc0000000 - 0xd0000000   ( 256 MB)
[    0.000000]     modules : 0xbf000000 - 0xc0000000   (  16 MB)
[    0.000000]       .text : 0xc0008000 - 0xc05c3000   (5868 kB)
[    0.000000]       .init : 0xc05c3000 - 0xc0600000   ( 244 kB)
[    0.000000]       .data : 0xc0600000 - 0xc065e320   ( 377 kB)
[    0.000000]        .bss : 0xc065e344 - 0xc068b424   ( 181 kB)
[    0.000000] NR_IRQS:396
[    0.000000] IRQ: Found an INTC at 0xfa200000 (revision 5.0) with 128 interrupts
[    0.000000] Total of 128 interrupts on 1 active controller
[    0.000000] OMAP clockevent source: GPTIMER2 at 24000000 Hz
[    0.000000] OMAP clocksource: GPTIMER1 at 32768 Hz
[    0.000000] sched_clock: 32 bits at 32kHz, resolution 30517ns, wraps every 131071999ms
[    0.000000] Console: colour dummy device 80x30
[    0.000183] Calibrating delay loop... 498.89 BogoMIPS (lpj=2494464)
[    0.058166] pid_max: default: 32768 minimum: 301
[    0.058319] Security Framework initialized
[    0.058441] Mount-cache hash table entries: 512
[    0.058898] CPU: Testing write buffer coherency: ok
[    0.059844] devtmpfs: initialized
[    0.080566] omap_hwmod: gfx: failed to hardreset
[    0.097320] omap_hwmod: pruss: failed to hardreset
[    0.098724] print_constraints: dummy:
[    0.099182] NET: Registered protocol family 16
[    0.101989] OMAP GPIO hardware version 0.1
[    0.105560] omap_mux_init: Add partition: #1: core, flags: 0
[    0.108520]  omap_i2c.1: alias fck already exists
[    0.109710]  omap2_mcspi.1: alias fck already exists
[    0.109985]  omap2_mcspi.2: alias fck already exists
[    0.110351]  edma.0: alias fck already exists
[    0.110382]  edma.0: alias fck already exists
[    0.110412]  edma.0: alias fck already exists
[    0.144836] bio: create slab <bio-0> at 0
[    0.147796] SCSI subsystem initialized
[    0.149993] usbcore: registered new interface driver usbfs
[    0.150421] usbcore: registered new interface driver hub
[    0.150695] usbcore: registered new device driver usb
[    0.150848] musb-ti81xx musb-ti81xx: musb0, board_mode=0x13, plat_mode=0x3
[    0.151245] musb-ti81xx musb-ti81xx: musb1, board_mode=0x13, plat_mode=0x1
[    0.152954] omap_i2c omap_i2c.1: bus 1 rev2.4.0 at 100 kHz
[    0.154815] tps65910 1-002d: could not be detected
[    0.155181] tca8418 keyscan key probe
[    0.155822] input: tca8418_keypad as /devices/platform/omap/omap_

The dmesg looks okay. The tca8418 code seems to print errors if anything went wrong. A couple things to check.

The file "/dev/input/event0" is a symbolic link to "/devices/platform/omap/omap_i2c.1/i2c-1/1-0034/input/input0".

In your event0 tests, you are executing as root.

You have reached the limits of my knowledge on the subject. Hopefully somebody more knowledgable than me can advise you.

Dear Sir,

I am using beaglebone white with linux kernel source ti-sdk-am335x-evm-06.00.00.00. 

I want to interface i2c based I/O expander tca6416 ic with beaglebone on i2c-1. I have modified am335xboard.c file and selected the tca6416 option in make menuconfig option. I then compiled linux kernel and booted the board with generated uImage.

I can see the entry of i2c-2 in /dev folder but there is no entry of tca6416-keypad driver in /dev/input device. I have checked that the tca6416-keypad.c in /drivers/input/keyboard folder of linux 3.2 kernel source have the capability for the required application.

My application is to check the port status of tca6416 input pins and get interrupt alert when there is any change in port status.

I want to read the port status whenever there is interrupt in my user application.

Below are contents of beaglebone board.c file.

static struct tca6416_button tca6416_gpio_keys[] = {
KEYPAD_BUTTON(KEY1,1,EV_KEY),
KEYPAD_BUTTON(KEY2,1,EV_KEY),
KEYPAD_BUTTON(KEY3,1,EV_KEY),
KEYPAD_BUTTON(KEY4,1,EV_KEY),
KEYPAD_BUTTON(KEY5,1,EV_KEY),
KEYPAD_BUTTON(KEY6,1,EV_KEY),
KEYPAD_BUTTON(KEY7,1,EV_KEY),
KEYPAD_BUTTON(KEY8,1,EV_KEY),

};

static struct tca6416_keys_platform_data am335x_tca6416_keys_info = {

.buttons = tca6416_gpio_keys,
.nbuttons = ARRAY_SIZE(tca6416_gpio_keys),
.rep = 0, /* enable input subsystem auto repeat */
.pinmask = 0,
.invert = 0,
.irq_is_gpio = 32, //GPIO1_0
.use_polling=0, /* use polling if Interrupt is not connected*/
};

static struct i2c_board_info __initdata am335x_i2c1_boardinfo[] = { //Ajay added
{
I2C_BOARD_INFO("tca6416-keypad", 0x20),
.platform_data = &am335x_tca6416_keys_info,
},
};
/***************************************************/
static struct i2c_board_info am335x_i2c2_boardinfo[] = {

};

static void i2c2_init(int evm_id, int profile)
{
setup_pin_mux(i2c2_pin_mux);
omap_register_i2c_bus(3, 100, am335x_i2c2_boardinfo,
ARRAY_SIZE(am335x_i2c2_boardinfo));
return;
}

My board bootlog shows that it has detected the i2c device at 400khz on i2c-2 port.

Can you please guide me that what is the issue that there is no entry of tca6416 device in /dev/input.

and 

Also, how can we read the status of port of tca6416 input on user application.

Thanks & Regards,

Ajay Rajput

No experience with the AM335x BeagleBone or tca6416. Some guesses. Are you compiling the tca6416 as a module or as a built-in? A module might require you to manually insmod the module or copy the module into the "/lib/modules" area.

Seems the only other example of the tca6416 is in the mackerel baord. Using that board's platform code as a guide, your code might look something like this:

----------------------
// From arch/arm/mach-shmobile/board-mackerel.c
#define KEYPAD_BUTTON(ev_type, ev_code, act_low) \
{\
  .type = ev_type,\
  .code = ev_code,\
  .active_low = act_low,\
}
#define KEYPAD_BUTTON_LOW(event_code) KEYPAD_BUTTON(EV_KEY, event_code, 1)

static struct tca6416_button tca6416_gpio_keys[] = {
  KEYPAD_BUTTON_LOW(KEY1), //<--- changed
  KEYPAD_BUTTON_LOW(KEY2), //<--- changed
  KEYPAD_BUTTON_LOW(KEY3), //<--- changed
  KEYPAD_BUTTON_LOW(KEY4), //<--- changed
  KEYPAD_BUTTON_LOW(KEY5), //<--- changed
  KEYPAD_BUTTON_LOW(KEY6), //<--- changed
  KEYPAD_BUTTON_LOW(KEY7), //<--- changed
  KEYPAD_BUTTON_MOW(KEY8), //<--- changed
};

static struct tca6416_keys_platform_data am335x_tca6416_keys_info = {
  .buttons = tca6416_gpio_keys,
  .nbuttons = ARRAY_SIZE(tca6416_gpio_keys),
  .rep = 0, /* enable input subsystem auto repeat */
  .pinmask = 0xFF, //<------------ Was 0
  .invert = 0,
  .irq_is_gpio = 32, //GPIO1_0
  .use_polling=0, /* use polling if Interrupt is not connected*/
};

static struct i2c_board_info __initdata am335x_i2c1_boardinfo[] = { //Ajay added
{
  //<---- Moved assumes tca6416 is connected to i2c2
};
/***************************************************/
static struct i2c_board_info am335x_i2c2_boardinfo[] = {
  {
    I2C_BOARD_INFO("tca6416-keys", 0x20), //<------ Was "tca6416-keypad"
    .platform_data = &am335x_tca6416_keys_info,
// .irq = ? // TODO
  },
};

static void i2c2_init(int evm_id, int profile)
{
  setup_pin_mux(i2c2_pin_mux);
  omap_register_i2c_bus(3, 100, am335x_i2c2_boardinfo,
  ARRAY_SIZE(am335x_i2c2_boardinfo));
  return;
}

Dear Sir,

Thanks for the reply. 

I am compiling the tca6416 as built in static module in kernel.

After your suggestion, i am able to generate entry of tca6416 device in /dev/input/ as event0 after booting the beaglebone with new uImage after correction applied.

Can you suggest me that how should i read the port status of tca6416 inputs from /dev/input/event0 device in user space program.

Thanks & Regards,

Ajay Rajput

Dear Sir, 

I would also want to know that in my previous query, what should be address/value of KEY1 to KEY8.

I my board file.c , i have kept

#define KEY1 0

#define KEY2 1

#define KEY3 2

#define KEY4 3

#define KEY5 4

#define KEY6 5

#define KEY7 6

#define KEY8 7

I am doubtful that above values are wrong, but i am not aware what should be the values.

Thanks & Regards,

Ajay

I think you should use the predefined linux kernel input values. You might not have to but it is safer if kernel input driver that depends on it. Your code would then look something like this:
-----------kernel----------
#include <linux/input.h> // For EV_KEY, KEY_1-KEY8

static struct tca6416_button tca6416_gpio_keys[] = {
// code active_low type
  {KEY_1, 1, EV_KEY},
  {KEY_2, 1, EV_KEY},
  {KEY_3, 1, EV_KEY},
  {KEY_4, 1, EV_KEY},
  {KEY_5, 1, EV_KEY},
  {KEY_6, 1, EV_KEY},
  {KEY_7, 1, EV_KEY},
  {KEY_8, 1, EV_KEY},
};

static struct tca6416_keys_platform_data am335x_tca6416_keys_info = {
  .buttons = tca6416_gpio_keys,
  .nbuttons = ARRAY_SIZE(tca6416_gpio_keys),
  .rep = 0, /* enable input subsystem auto repeat */
  .pinmask = 0xFF,
  .invert = 0,
  .irq_is_gpio = 32, //GPIO1_0
  .use_polling=0, /* use polling if Interrupt is not connected*/
};

static struct i2c_board_info am335x_i2c2_boardinfo[] = {
  {
    I2C_BOARD_INFO("tca6416-keys", 0x20),
    .platform_data = &am335x_tca6416_keys_info,
// .irq = ? // TODO
  },
};

static void i2c2_init(int evm_id, int profile)
{
  setup_pin_mux(i2c2_pin_mux);
  omap_register_i2c_bus(3, 100, am335x_i2c2_boardinfo,
  ARRAY_SIZE(am335x_i2c2_boardinfo));
  return;
}
-----------userspace----------
// You must path in the linux kernel include directory for this
#include <linux/input.h> // For EV_KEY, KEY_1-KEY8
int fd;
struct input_event ev;
int size = sizeof (struct input_event);

fd = open ("/dev/input/event0", O_RDONLY);
read(fd, &ev, size);
if(ev.type == EV_KEY)
{
  switch(ev.code)
  {
    case KEY_1: printf("1 is %d\n", ev.value); break;
    ...
    case KEY_8: printf("8 is %d\n", ev.value); break;
  }
}
----
The BTN_1 to BTN_8 may be decriptively better. Please start a new thread if you have another problem.

Dear Sir,

Thanks for the reply.

As per you suggestion, i am able to detect the keys in user space  application.

Actual problem in board.c file was as below:

static struct tca6416_keys_platform_data am335x_tca6416_keys_info = {
  .buttons = tca6416_gpio_keys,
  .nbuttons = ARRAY_SIZE(tca6416_gpio_keys),
  .rep = 0, /* enable input subsystem auto repeat */
  .pinmask = 0xFF,
  .invert = 0,
  .irq_is_gpio = 1, <-- it should be 0 or 1 flag //1 if interrupt is required
  .use_polling=0, /* use polling if Interrupt is not connected*/
};

static struct i2c_board_info am335x_i2c2_boardinfo[] = {
  {
    I2C_BOARD_INFO("tca6416-keys", 0x20),
    .platform_data = &am335x_tca6416_keys_info,
    .irq = 32 //for GPIO1_0 pin as interrupt source should be define here.
  },
};

Thanks.

Regards,
Ajay Rajput

I am not clear on what you are saying. What are the symptoms of the problem? Are you saying you are trying to use interrupt driven events? From the userspace side that requires the use of poll(). Assumes the driver's interrupt has been setup correctly.