em28xx: msi Digivox ATSC board id [0db0:8810]

Am 02.12.2012 18:18, schrieb Frank Schäfer:
> Am 02.12.2012 15:23, schrieb Antti Palosaari:
>> On 12/02/2012 01:44 PM, Frank Schäfer wrote:
>>> Am 30.11.2012 02:45, schrieb Matthew Gyurgyik:
>>>> On 11/29/2012 02:28 PM, Frank Schäfer wrote:
>>>>> Matthew, stay tuned but be patient. ;) Regards, Frank
>>>> Sure thing, just let me know what you need me to do!
>>>>
>>> Ok, please test the attached experimental patch and post the dmesg
>>> output.
>>>
>>> Open questions:
>>> - setting of EM2874 register 0x0f (XCLK): the Windows doesn't touch this
>>> register, so the default value seems to be used.
>>>    The patch adds 2 debugging lines to find out the default which
>>> default
>>> value the em2874 uses.
>>>    For now, I've set this to 12MHz, because the picture shows a 12MHz
>>> oszillator.
>>> - meaning of the gpio sequence / gpio lines assignment (see comments in
>>> the patch).
>>> - remote control support: looking at the product picture on the MSI
>>> website,
>>>    the remote control could be the same as sues by the Digivox III. But
>>> that's just a guess.
>>> - LGDT3305 configuration: a few parameters can not be taken form the USB
>>> log. Will ask the author of the driver for help.
>>>
>>> But let's do things step by step and see what happens with the patch.
>>>
>>> Regards,
>>> Frank
>>>
>> Hello
>> I looked the patch quickly and here are the findings:
>> I2C addresses are in "8-bit" format. Will not work. Example for tuner,
>> 0xc0 should be 0x60. Same for the demod. Due to that, no worth to test
>> patch. I2C addresses are normally 7-bit, but "unofficial" 8-bit
>> notation is also used widely. em28xx uses official notation as almost
>> all other media drivers.
> Argh, yeah, I didn't check that. The mixed usage of 7 and 8 bit
> notations is a mess.
>
>> You are using tda18271c2dd tuner driver. I recommended to change to
>> the other driver named tda18271. tda18271c2dd is very bad choice in
>> that case as it discards all the I2C error without any error logging
>> and just silently ignores. I remember case when I used that tuner
>> driver for one em28xx + drx-k combination and wasted very many hours
>> trying to get it working due to missing error logging :/
> Ok, thanks. So we have two drivers for the same chip and tda18271c2dd is
> deprecated ? Can both drivers handle both chip models ?
> I thought tda18271c2dd is for the c2 model of the chip and tda18271 for
> the "normal" model...
> I also wonder why tda18271 is in media/tuners while tda18271c2dd is in
> media/dvb-frontends ?
>
>> Don't care XCLK register, it most likely will just as it is. There is
>> many EM2874 boards already supported.
>>
>> 12MHz clock is correct and it is seen from the hardware. Generally
>> 12MHz xtal is used very often for USB (device to device) as it is
>> suitable reference clock.
> Likely. But XCLK register also controls a few other things (e.g. remote
> control settings) and the em28xx driver overwrites the default register
> content in any case.
> So let's see what dmesg tells us.
>
>> According to comments, GPIO7 is used when streaming is started /
>> stopped. It is about 99% sure LOCK LED :)
>>
>> When you look sniffs and see some GPIO is changed for example just
>> before and after tuner communication you could make assumption it does
>> have something to do with tuner (example tuner hw reset / standby).
> That's possible, but on the other hand, there is a delay of 20ms after
> GPIO_7. That shouldn't be necessary for a LED.
> Any idea what GPIO_0 is ? it is to set to high (50ms delay afterwards)
> when the first chunk of data is read from the eeprom and set back to low
> afterwards.
>
>> You should look used intermediate frequencies from the tuner driver
>> and configure demod according to that. OK, 3-4 MHz sounds very
>> reasonable low-IF values used with tda18271. tda18271 driver supports
>> also get IF callback, but demod driver not. That callback allows
>> automatically configure correct IF according to what tuner uses.
>> Anyhow, in that case you must ensure those manually from tuner driver
>> as demod driver does not support get IF. IF is *critical*, if it is
>> wrong then nothing works (because demodulator does not get signal from
>> tuner).
> Ok, that means the 'qam_if_khz' and 'vsb_if_khz' in struct
> lgdt3305_config are mandatory values and must be set manually.
> Looking into the tda18271 driver, vsb_if_khz should be set to 3250.
> That's what the other em28xx board uses, too.
>
> I will send an updated version of the patch soon. Thanks for your comments.

Here is v2 of the patch (attached).

Antti, could you please take a look at the std_map for the tuner ?
I'm not sure what the correct and complete map is.

For a first test, I've selected the same std_map as used with the KWorld
A340 (LGDT3304 + TDA18271 C1/C2):

static struct tda18271_std_map kworld_a340_std_map = {
    .atsc_6   = { .if_freq = 3250, .agc_mode = 3, .std = 0,
              .if_lvl = 1, .rfagc_top = 0x37, },
    .qam_6    = { .if_freq = 4000, .agc_mode = 3, .std = 1,
              .if_lvl = 1, .rfagc_top = 0x37, },
};

These are the relevant tda18271 register values the taken from Matthews
USB-log:

EP3 (0x05): 0x1d
EP4 (0x06): 0x60
EB22 (0x25): 0x37

The LGDT3305 is configured for QAM and IF=4000kHz, which leads to a
tda18271_std_map_item with

{
 .if_freq = 4000,
 .agc_mode = 3,
 .std = 5,
 .fm_rfn = 0,
 .if_lvl = 0,
 .rfagc_top = 0x37,
 }

According to the datasheet and tda18271-maps.c, this should be qam_6,
qam_7 or qam_8.

Do we need further USB-logs from the Windows driver ?
And if yes, do you have any advice for Matthew how to create them ?

Regards,
Frank

> Regards,
> Frank
>
>> regards
>> Antti
>>

em28xx: msi Digivox ATSC board id [0db0:8810]

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