On Tue, Jan 4, 2022 at 9:57 AM Lad, Prabhakar <prabhakar.csengg@xxxxxxxxx> wrote: > > Hi Eugen, > > On Mon, Jan 3, 2022 at 11:29 AM <Eugen.Hristev@xxxxxxxxxxxxx> wrote: > > > > On 12/21/21 5:11 PM, Lad, Prabhakar wrote: > > > Hi Eugen, > > > <snip> > > > could you give it a shot with yavta please. > > > > Hello Lad, > > > > I debugged this further, and I have some news: > > > > It looks like the 'write 0x2 to SYS_CLTR0' does not fail itself, rather > > the sensor refuses to accept a power up. > > > > I tried to read the register before the write, and it reads 0x42. > > Then, I tried to write 0x42 back, and it works fine. > > So, I do not think there is a problem with i2c communication. > > The only problem is that the sensor refuses to power up (accept the 0x2 > > into the SYS_CTRL_0 ), due to an unknown (to me) reason. > > > That's strange. > > > If the power up is performed at the initialization phase, it works. > > > > I also tried to capture with v4l2-ctl, and the result is the same. > > > you mean yavta ? > > > Which of the init configuration set of registers your test is using? > I have been testing 320x240 and 640x480. Could you give that a try please? > > > It may be that it does not work in a specific config . > > > > The datasheet which I have does not claim that the 'power up' might fail > > in some circumstances. > > > Let me check if I can ping OmniVision FAE. > Fyi.. I got the below feedback from OmniVision FAE. SW standby bit is working as expected from my side. As far as the sensor initialization is concerned we use HW power up sequence defined in the datasheet followed by SW initialization. SW initialization consist of the following :- 78 3103 11 ; I2C timing ( do not modify) 78 3008 82 ; SW reset 78 3008 42 ; Stop streaming 78 ……. Sensor settings for required mode 78 3008 02 ; Start streaming Note:- 0x3008[7] SW reset bit is volatile, as soon as a reset is applied the all the bits are cleared and 0x3008[7:0] set to default value hence should read 0x2 Cheers, Prabhakar
