AM335X的ADC驱动问题

我加载adc驱动的时候，怎么不能注册呢？3.14的内核，
按照这个配置的http://processors.wiki.ti.com/index.php/Linux_Core_ADC_User%27s_Guide#Sample_Application
把adc配成模块，手动安装，无法进入到probe函数（没有打印）。

static int tiadc_probe(struct platform_device *pdev)
[
printk("------>proben");
...
...
]

root@am335x-evm:/lib/modules/3.14.43-g875c69b/kernel/drivers/iio/adc# lsmod
Module Size Used by
kfifo_buf 2417 0
industrialio 46890 1 kfifo_buf
bufferclass_ti 5396 0
omaplfb 12042 0
snd_soc_evm 5589 0
pvrsrvkm 177007 2 bufferclass_ti,omaplfb
cryptodev 32483 0
snd_soc_davinci_mcasp 15606 2
lis3lv02d_i2c 3153 0
lis3lv02d 14936 1 lis3lv02d_i2c
snd_soc_tlv320aic3x 40349 1
input_polldev 3345 1 lis3lv02d

root@am335x-evm:/lib/modules/3.14.43-g875c69b/kernel/drivers/iio/adc# ls
ti_am335x_adc.ko
am335x_adc.ko m:/lib/modules/3.14.43-g875c69b/kernel/drivers/iio/adc# insmod ti_a
root@am335x-evm:/lib/modules/3.14.43-g875c69b/kernel/drivers/iio/adc#
root@am335x-evm:/lib/modules/3.14.43-g875c69b/kernel/drivers/iio/adc#
root@am335x-evm:/lib/modules/3.14.43-g875c69b/kernel/drivers/iio/adc#
root@am335x-evm:/lib/modules/3.14.43-g875c69b/kernel/drivers/iio/adc# lsmod
Module Size Used by
ti_am335x_adc 4562 0
kfifo_buf 2417 1 ti_am335x_adc
industrialio 46890 2 ti_am335x_adc,kfifo_buf
bufferclass_ti 5396 0
omaplfb 12042 0
snd_soc_evm 5589 0
pvrsrvkm 177007 2 bufferclass_ti,omaplfb
cryptodev 32483 0
snd_soc_davinci_mcasp 15606 2
lis3lv02d_i2c 3153 0
lis3lv02d 14936 1 lis3lv02d_i2c
snd_soc_tlv320aic3x 40349 1
input_polldev 3345 1 lis3lv02d


root@am335x-evm:~# ls -al /sys/bus/iio/devices/iio:device0/
ls: /sys/bus/iio/devices/iio:device0/: No such file or directory
root@am335x-evm:~# ls -al /sys/bus/iio/devices/
drwxr-xr-x 2 root root 0 Jul 6 22:15 .
drwxr-xr-x 4 root root 0 Jul 6 22:15 ..
root@am335x-evm:~#

下面是dts：
。。
&tscadc [
        adc [
            ti,adc-channels = <4 5 6 7>;
         ];
];
。。