Hi Ivaylo, On Fri, Jan 20, 2017 at 09:59:13AM +0200, Ivaylo Dimitrov wrote: > Hi, > > On 19.01.2017 23:49, Sakari Ailus wrote: > >Hi Pavel, > > > >On Wed, Jan 11, 2017 at 11:53:35PM +0100, Pavel Machek wrote: > >>From: Sakari Ailus <sakari.ailus@xxxxxx> > >> > >>In the vast majority of cases the bus type is known to the driver(s) > >>since a receiver or transmitter can only support a single one. There > >>are cases however where different options are possible. > >> > >>The existing V4L2 OF support tries to figure out the bus type and > >>parse the bus parameters based on that. This does not scale too well > >>as there are multiple serial busses that share common properties. > >> > >>Some hardware also supports multiple types of busses on the same > >>interfaces. > >> > >>Document the CSI1/CCP2 property strobe. It signifies the clock or > >>strobe mode. > >> > >>Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxx> > >>Signed-off-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@xxxxxxxxx> > >>Signed-off-by: Pavel Machek <pavel@xxxxxx> > >> > >>diff --git a/Documentation/devicetree/bindings/media/video-interfaces.txt b/Documentation/devicetree/bindings/media/video-interfaces.txt > >>index 9cd2a36..08c4498 100644 > >>--- a/Documentation/devicetree/bindings/media/video-interfaces.txt > >>+++ b/Documentation/devicetree/bindings/media/video-interfaces.txt > >>@@ -76,6 +76,11 @@ Optional endpoint properties > >> mode horizontal and vertical synchronization signals are provided to the > >> slave device (data source) by the master device (data sink). In the master > >> mode the data source device is also the source of the synchronization signals. > >>+- bus-type: data bus type. Possible values are: > >>+ 0 - MIPI CSI2 > >>+ 1 - parallel / Bt656 > >>+ 2 - MIPI CSI1 > >>+ 3 - CCP2 > > > >Actually, thinking about this again --- we only need to explictly specify > >busses if we're dealing with either CCP2 or CSI-1. The vast majority of the > >actual busses are and continue to be CSI-2 or either parallel or Bt.656. As > >they can be implicitly detected, we would have an option to just drop values > >0 and 1 from above, i.e. only leave CSI-1 and CCP2. For now, specifying > >CSI-2 or parallel / Bt.656 adds no value as the old DT binaries without > >bus-type will need to be supported anyway. > > > >> - bus-width: number of data lines actively used, valid for the parallel busses. > >> - data-shift: on the parallel data busses, if bus-width is used to specify the > >> number of data lines, data-shift can be used to specify which data lines are > >>@@ -112,7 +117,8 @@ Optional endpoint properties > >> should be the combined length of data-lanes and clock-lanes properties. > >> If the lane-polarities property is omitted, the value must be interpreted > >> as 0 (normal). This property is valid for serial busses only. > >>- > >>+- strobe: Whether the clock signal is used as clock or strobe. Used > >>+ with CCP2, for instance. > > > >How about the "ti,strobe-clock-inv" I proposed? No-one seems to know what > >this really truly means... or just drop it if it's not really needed. > > > > Not really :), see https://www.spinics.net/lists/linux-media/msg99802.html > and https://www.spinics.net/lists/linux-media/msg99800.html > > "clock/strobe", and "strobe-inv" are two distinct properties, see CSI1B_CTRL > description in OMAP TRM. BTW there is another property that is needed for > both n900 cameras to operate correctly (VP_CLK_POL, bit 12 from the same > reg), but that can be added later on when we have the other bits in place. Oh, indeed, my mistake. Please ignore that comment. -- Sakari Ailus e-mail: sakari.ailus@xxxxxx XMPP: sailus@xxxxxxxxxxxxxx -- 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
