Re: Antwort: Re: [PATCH 1/2] mt9v022: fix pixel clock

[Guennadi Liakhovetski <g.liakhovetski@gmx.de>]

Hello Teresa

Thanks very much for your extensive testing! I'm afraid, I don't have the 
time right now to go through all those register settings, so, can we, 
maybe, do the following: we currently have two platforms in the mainline, 
that use mt9v022. We believe, that the driver itself implements the pixel 
clock edge configuration wrongly. Could you please provide patches to

1. fix mt9v022 to match our new understanding
2. if needed - additionally fix pcm037 by setting the 
   SOCAM_SENSOR_INVERT_PCLK flag
3. same for pcm990 / pcm027

I also noticed your "wrong colours" result - if colours are completely 
swapped, maybe you just have to adjust your Bayer decoder?

Once we get those patches, I'll try to test them, but I've a very tight 
schedule atm, so, maybe I'll just believe you to get them on time for 
2.6.39.

Thanks
Guennadi

On Tue, 12 Apr 2011, Teresa Gamez wrote:

> Am Freitag, den 08.04.2011, 15:27 +0200 schrieb Teresa Gamez:
> > Hello Guennadi,
> > 
> > Am Donnerstag, den 07.04.2011, 14:41 +0200 schrieb Guennadi
> > Liakhovetski:
> > > Hello Teresa
> > > 
> > > On Thu, 7 Apr 2011, Teresa Gamez wrote:
> > > 
> > > > Hello Guennadi,
> > > > 
> > > > the datasheet also says (see table 3):
> > > > 
> > > > <quote>
> > > > Pixel clock out. DOUT is valid on rising edge of this
> > > > clock.
> > > > </quote>
> > > > 
> > > > There is a difference between DOUT beeing vaild and DOUT beeing set up. 
> > > > So does SOCAM_PCLK_SAMPLE_RISING mean that the data is valid at rising 
> > > > edge or 
> > > > does it mean the data is set up at rising edge? 
> > > 
> > > Hm, yeah, looks like a typical example of a copy-paste datasheet to me:-( 
> > > And now we don't know which of the two is actually supposed to be true. As 
> > > for "set up" vs. "valid" - not sure, whether there is indeed a difference 
> > > between them. To me "set up _TO_ the rising edge" is a short way to set 
> > > "set up to be valid at the rising edge," however, I might be wrong. Can 
> > > you tell me in more detail what and where (at the sensor board or on the 
> > > baseboard) you measured and what it looked like? I think, Figure 7 and the 
> > > description below it are interesting. From that diagram I would indeed say 
> > > indeed the DOUT pins are valid and should be sampled at the rising edge by 
> > > default - when bit 4 in 0x74 is not set. SOCAM_PCLK_SAMPLE_RISING means, 
> > > that the data should be sampled at the rising of pclkm, i.e., it is valid 
> > > there.
> > 
> > I meassured the outgoing pins from the baseboard to the camera board and
> > checked the PCLK and D0 to see at which point the data is valid. I have
> > also checked the quality of the image.
> > All tests where made with sensor_type=color
> > 
> > My results for pcm038 are with following register settings:
> > 
> > mx2_camera
> > 0x0 CSICR1:		0x10020b92
> > -> rising edge
> > 
> > mt9v022
> > 0x74 PIXCLK_FV_LV:      0x00000010
> > -> rising edge (which I think is falling edge)
> > 
> > meassured: falling edge (ugly image, wrong colors)
> > 
> > Now I set the SOCAM_SENSOR_INVERT_PCLK flag in the platformcode for the
> > mt9v022:
> > 
> > mx2_camera
> > 0x0 CSICR1		  0x10020b92
> > -> rising edge 
> > 
> > mt9v022
> > 0x74 PIXCLK_FV_LV         0x00000000
> > -> falling edge (which I think is rising edge)
> > 
> > meassured: rising edge (image is OK)
> > 
> > Now changed the PCLK of the mx2_camera:
> > 
> > mx2_camera
> > 0x0 CSICR1               0x10020b90
> > -> falling edge 
> > 
> > mt9v022
> > 0x74 PIXCLK_FV_LV        0x00000010
> > -> rising edge (which I think is falling edge)
> > 
> > meassured: falling edge (image is OK)
> > 
> > > 
> > > So, yes, if your measurements agree with figure 7 from the datasheet, we 
> > > shall assume, that the driver implements the pclk polarity wrongly. But 
> > > the fix should be more extensive, than what you've submitted: if we invert 
> > > driver's behaviour, we should also invert board configuration of all 
> > > driver users: pcm990 and pcm037. Or we have to test them and verify, that 
> > > the inverted pclk polarity doesn't megatively affect the image quality, or 
> > > maybe even improves it.
> > > 
> > > Thanks
> > > Guennadi
> > > 
> > > > I have tested this with a pcm038 but I will also make meassurements with 
> > > > the pcm037.
> > > > 
> > 
> > Same results with the pcm037:
> > 
> > mx3_camera
> > 0x60 CSI_SENS_CONF:		0x00000700
> > -> rising edge
> > 
> > mt9v022
> > 0x74 PIXCLK_FV_LV:		0x00000010
> > -> rising edge (which I think is falling edge)
> > 
> > meassured: falling edge (ulgy image, looks like b/w with pixel errors)
> > 
> > Set SOCAM_SENSOR_INVERT_PCLK flag in the platformcode for the mt9v022:
> > mx3_camera
> > 0x60 CSI_SENS_CONF:		0x00000700
> > -> rising edge
> > 
> > mt9v022
> > 0x74 PIXCLK_FV_LV		0x00000000
> > -> falling edge (which I think is rising edge)
> > 
> > meassured: rising edge (image is OK)
> > 
> > Additionally set MX3_CAMERA_PCP of the mx3_camera flags 
> > 
> > mx3_camera
> > 0x60 CSI_SENS_CONF:		0x00000708
> > -> falling edge
> > 
> > mt9v022
> > 0x74 PIXCLK_FV_LV:       	0x00000010
> > -> rising edge (which I think is falling edge)
> > 
> > meassured: falling edge (image is OK)
> > 
> > Removed SOCAM_SENSOR_INVERT_PCLK flag for the mt9v022:
> > 
> > mx3_camera
> > 0x60 CSI_SENS_CONF:		0x00000708
> > -> falling edge
> > 
> > mt9v022
> > 0x74 PIXCLK_FV_LV		0x00000000
> > -> falling edge (which I think is rising edge)
> > 
> > meassured: risging edge (ugly image, looks like the first one)
> > 
> > I have noticed that on our pcm037 BSP the SOCAM_SENSOR_INVERT_PCLK flag
> > for the camera was set to "fix" this issue.
> > I will continue this test on the pcm990.
> > 
> 
> Got the same result with the pcm990:
> 
> pxa_camera
> 0x50000010 CICR4:	0x00880001
> 			-> rising edge (0 << 22)
> mt9v022
> 0x74 PIXCLK_FV_LV:      0x00000010
> 			-> rising edge (1 << 4) (which I think is falling edge)
> 
> meassured: falling edge (some pixel have wrong colors)
> 
> ---
> Now set the SOCAM_SENSOR_INVERT_PCLK for mt9v022:
> 
> pxa_camera
> 0x50000010 CICR4:	0x00880001
> 			-> rising edge (0 << 22)
> 
> mt9v022
> 0x74 PIXCLK_FV_LV:	0x00000000
> 			-> falling edge (0 << 4) (which I think is rising edge)
> 
> meassured: rising edge (image is OK)
> 
> ---
> Additionaly set the PXA_CAMERA_PCP flag:
> 
> pxa_camera
> 0x50000010 CICR4:	0x00c80001
> 			-> falling edge (1 << 22)
> 
> mt9v022
> 0x74 PIXCLK_FV_LV:	0x00000010
> 			-> rising edge (1 << 4) (which I think is falling edge)
> 
> meassured: falling edge (image is OK)
> 
> ---
> Removed SOCAM_SENSOR_INVERT_PCLK again:
> 
> pxa_camera
> 0x50000010 CICR4:       0x00c80001
> 			-> falling edge (1 << 22)
> 
> mt9v022
> 0x74 PIXCLK_FV_LV: 	0x00000000
>         	 	    -> falling edge (0 << 4) (which I think is rising edge)
> 
> meassured: rising edge (same as above, image shows wrong colored pixels) 
> 
> 
> I hope thats sufficed.
> 
> Teresa
> 
> 

---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/