Re: [PATCH 5/12] tm6000: update init table and sequence for tm6010

[Mauro Carvalho Chehab <mchehab@redhat.com>]

Stefan Ringel wrote:
> Am 08.02.2010 18:34, schrieb Stefan Ringel:
>> Am 08.02.2010 18:29, schrieb Mauro Carvalho Chehab:
>>   
>>> Stefan Ringel wrote:
>>>   
>>>     
>>>> Am 08.02.2010 12:37, schrieb Mauro Carvalho Chehab:
>>>>     
>>>>       
>>>>> Mauro Carvalho Chehab wrote:
>>>>>   
>>>>>       
>>>>>         
>>>>>>> +		tm6000_read_write_usb (dev, 0xc0, 0x10, 0x7f1f, 0x0000, buf, 2);
>>>>>>>       
>>>>>>>           
>>>>>>>             
>>>>>   
>>>>>       
>>>>>         
>>>>>> Most of the calls there are read (0xc0). I don't know any device that requires
>>>>>> a read for it to work. I suspect that the above code is just probing to check
>>>>>> what i2c devices are found at the board.
>>>>>>     
>>>>>>         
>>>>>>           
>>>>> Btw, by looking at drivers/media/dvb/frontends/zl10353_priv.h, we have an idea
>>>>> on what the above does:
>>>>>
>>>>> The register 0x7f is:
>>>>>
>>>>>         CHIP_ID            = 0x7F,
>>>>>
>>>>> So, basically, the above code is reading the ID of the chip, likely to be sure that it
>>>>> is a Zarlink 10353.
>>>>>
>>>>> Cheers,
>>>>> Mauro
>>>>> --
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>>>>>   
>>>>>       
>>>>>         
>>>> yes, but that's for activating Zarlink zl10353 and checking it --> hello
>>>> Zarlink? If doesn't use that sequence, then cannot use Zarlink zl10353.
>>>>
>>>>     
>>>>       
>>> Are you sure about that? Is this a new bug on tm6000?
>>>
>>> Anyway, the proper place for such code is inside zl10353 driver, not outside.
>>>
>>>   
>>>     
>> It cannot activate after load xc3028 firmware.
>>
>>   
> That part is I think it's board specific or tm6010.
> 
Probably yet-another-i2c-bug-on-tm6000... Ah, well...

then, convert this call into an i2c call. You may get one example of such in em28xx-cards.
In that specific case, em28xx-based webcams can be shipped with more than one different
sensor. So, the driver needs to read the sensor from I2C:

        rc = i2c_master_recv(&dev->i2c_client, (char *)&version_be, 2);
        if (rc != 2)
                return -EINVAL;

Of course, you need to be sure to register the i2c bus before calling i2c_master_recv.

-- 

Cheers,
Mauro