View Single Post
Old 06-30-2012, 09:54 AM   #10
baf
Evangelist
baf ought to be getting tired of karma fortunes by now.baf ought to be getting tired of karma fortunes by now.baf ought to be getting tired of karma fortunes by now.baf ought to be getting tired of karma fortunes by now.baf ought to be getting tired of karma fortunes by now.baf ought to be getting tired of karma fortunes by now.baf ought to be getting tired of karma fortunes by now.baf ought to be getting tired of karma fortunes by now.baf ought to be getting tired of karma fortunes by now.baf ought to be getting tired of karma fortunes by now.baf ought to be getting tired of karma fortunes by now.
 
Posts: 405
Karma: 2330752
Join Date: May 2012
Device: kt
In 5.1 kernel they build it without mma8453. In arch/arm/mach-mx5/mx50_yoshi.c:
Code:
static struct i2c_board_info mxc_i2c0_board_info[] = {
        {
         .type = "MX50_Proximity",
         .addr = 0x0D,
        },
        #ifdef CONFIG_MX50_YOSHI_MMA8453
        {
         .type = "mma8453",
         .addr = 0x1C,
        },
        #endif

};
So i2c device is not instantiated automagically.

However I scanned i2c bus and device with address 0x1c is located on bus 0:

Code:
[root@kindle test]# ./i2cdetect 0
WARNING! This program can confuse your I2C bus, cause data loss and worse!
I will probe file /dev/i2c/0.
I will probe address range 0x03-0x77.
Continue? [Y/n] 
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:          -- -- -- -- -- -- -- -- -- -- -- -- -- 
10: -- -- -- -- -- -- -- -- -- -- -- -- 1c -- -- -- 
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
70: -- -- -- -- -- -- -- --
To instantiate it manualy I did:

Code:
[root@kindle test]# echo mma8453 0x1c > /sys/devices/virtual/i2c-adapter/i2c-0/new_device
In dmesg:

Code:
i2c-adapter i2c-0: The new_device interface is still experimental and may change in a near future
input: mma8453 as /devices/virtual/i2c-adapter/i2c-0/0-001c/input/input5
check mma8453 chip ID
mma8453 0-001c: build time Nov  9 2011 15:38:29
i2c-adapter i2c-0: new_device: Instantiated device mma8453 at 0x1c
Also /dev/input/event4 is created, which gives some output when I move device.
baf is offline   Reply With Quote