On 19 July 2012 20:40, Sylwester Nawrocki <sylvester.nawrocki@gmail.com> wrote:

Hi Sangwook,

On 07/19/2012 02:14 PM, Sangwook Lee wrote:
> Add factory default settings for S5K4ECGX sensor registers.
> I copied them from the reference code of Samsung S.LSI.

I'm pretty sure we can do better than that. I've started S5K6AAFX sensor
driver development with similar set of write-only register address/value
arrays, that stored mainly register default values after the device reset,
or were configuring presets that were never used.

If you lok at the s5k6aa driver, you'll find only one relatively small
array of register values for the analog processing block settings.
It's true that I had to reverse engineer a couple of things, but I also

had a relatively good datasheet for the sensor.

Yes, I already saw analog settings in s5k6aa. Compared to s5k6aa,
I couldn't also understand why the sensor has lots of initial values.
Is it because s5k4ecgx is slightly more complicated than s5k6aa ?

> According to comments from the reference code, they do not
> recommend any changes of these settings.

Yes, but it doesn't mean cannot convert, at least part of, those ugly
tables into function calls.

Yes, the biggest table seems to be one time for boot-up, at least I need to
remove one more macro (token)

Have you tried to contact Samsung S.LSI for a datasheet that would
contain better registers' description ?

As you might know, there is a limitation for me to get those information. :-)
Instead, if I look into the source code of Google Nexus S which uses s5k4ecgx,

https://android.googlesource.com/kernel/samsung.git

I can discover that both Google and Samsung are using the same huge table
just for initial settings from the sensor booting-up. I added the original author
of this sensor driver. Hopes he might add some comments :-)

Thanks
Sangwook

--

Thanks,
Sylwester