On Fri, 2017-02-17 at 10:56 +0000, Russell King - ARM Linux wrote: > On Fri, Feb 17, 2017 at 11:39:11AM +0100, Philipp Zabel wrote: > > On Thu, 2017-02-16 at 22:57 +0000, Russell King - ARM Linux wrote: > > > On Thu, Feb 16, 2017 at 02:27:41PM -0800, Steve Longerbeam wrote: > > > > > > > > > > > > On 02/16/2017 02:20 PM, Russell King - ARM Linux wrote: > > > > >On Wed, Feb 15, 2017 at 06:19:02PM -0800, Steve Longerbeam wrote: > > > > >>In version 4: > > > > > > > > > >With this version, I get: > > > > > > > > > >[28762.892053] imx6-mipi-csi2: LP-11 timeout, phy_state = 0x00000000 > > > > >[28762.899409] ipu1_csi0: pipeline_set_stream failed with -110 > > > > > > > > > > > > > Right, in the imx219, on exit from s_power(), the clock and data lanes > > > > must be placed in the LP-11 state. This has been done in the ov5640 and > > > > tc358743 subdevs. > > > > > > The only way to do that is to enable streaming from the sensor, wait > > > an initialisation time, and then disable streaming, and wait for the > > > current line to finish. There is _no_ other way to get the sensor to > > > place its clock and data lines into LP-11 state. > > > > I thought going through LP-11 is part of the D-PHY transmitter > > initialization, during the LP->HS wakeup sequence. But then I have no > > access to MIPI specs. > > The D-PHY transmitter initialisation *only* happens as part of the > wake-up from standby to streaming mode. That is because Sony expect > that you program the sensor, and then when you switch it to streaming > mode, it computes the D-PHY parameters from the PLL, input clock rate > (you have to tell it the clock rate in 1/256 MHz units), number of > lanes, and other parameters. > > It is possible to program the D-PHY parameters manually, but that > doesn't change the above sequence in any way (it just avoids the > chip computing the values, it doesn't result in any change of > behaviour on the bus.) > > The IMX219 specifications are clear: the clock and data lines are > held low (LP-00 state) after releasing the hardware enable signal. > There's a period of chip initialisation, and then you can access the > I2C bus and configure it. There's a further period of initialisation > where charge pumps are getting to their operating state. Then, you > set the streaming bit, and a load more initialisation happens before > the CSI bus enters LP-11 state and the first frame pops out. When > entering standby, the last frame is completed, and then the CSI bus > enters LP-11 state. How about firing off a thread in imx6-mipi-csi2 prepare_stream that spins on the LP-11 check and then continues with the receiver D-PHY initialization once the condition is met? I think we should have at least 100 us to do this, but maybe the IMX219 can be programmed to stay in LP-11 for a longer time. > SMIA are slightly different - mostly following what I've said above, > but the clock and data lines are tristated after releasing the > xshutdown signal, and they remain tristated until the clock line > starts toggling before the first frame appears. There appears to > be no point that the clock line enters LP-11 state before it starts > toggling. When entering standby, the last frame is completed, and > the CSI bus enters tristate mode (so floating.) There is no way to > get these sensors into LP-11 state. I have no idea what to do about those. regards Philipp -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
