From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steve Longerbeam Subject: Re: [PATCH v3 01/24] [media] dt-bindings: Add bindings for i.MX media driver Date: Mon, 16 Jan 2017 09:13:39 -0800 Message-ID: <3fbe85f8-ddc2-2299-ac9d-47d07485c162@gmail.com> References: <1483755102-24785-1-git-send-email-steve_longerbeam@mentor.com> <1483755102-24785-2-git-send-email-steve_longerbeam@mentor.com> <1484308551.31475.23.camel@pengutronix.de> <1484568579.8415.91.camel@pengutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1484568579.8415.91.camel-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Philipp Zabel Cc: robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, mark.rutland-5wv7dgnIgG8@public.gmane.org, shawnguo-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, kernel-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org, fabio.estevam-3arQi8VN3Tc@public.gmane.org, linux-I+IVW8TIWO2tmTQ+vhA3Yw@public.gmane.org, mchehab-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, hverkuil-qWit8jRvyhVmR6Xm/wNWPw@public.gmane.org, nick-gcszYUEDH4VrovVCs/uTlw@public.gmane.org, markus.heiser-O6JHGLzbNUwb1SvskN2V4Q@public.gmane.org, laurent.pinchart+renesas-ryLnwIuWjnjg/C1BVhZhaw@public.gmane.org, bparrot-l0cyMroinI0@public.gmane.org, geert-Td1EMuHUCqxL1ZNQvxDV9g@public.gmane.org, arnd-r2nGTMty4D4@public.gmane.org, sudipm.mukherjee-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, minghsiu.tsai-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org, tiffany.lin-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org, jean-christophe.trotin-qxv4g6HH51o@public.gmane.org, horms+renesas-/R6kz+dDXgpPR4JQBCEnsQ@public.gmane.org, niklas.soderlund+renesas-1zkq55x86MTxsAP9Fp7wbw@public.gmane.org, robert.jarzmik-GANU6spQydw@public.gmane.org, songjun.wu-UWL1GkI3JZL3oGB3hsPCZA@public.gmane.org, andrew-ct.chen-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org, gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-media-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, devel-gWbeCf7V1WCQmaza687I9mD2FQJk+8+b@public.gmane.org, Steve Longerbeam List-Id: devicetree@vger.kernel.org On 01/16/2017 04:09 AM, Philipp Zabel wrote: > On Fri, 2017-01-13 at 11:03 -0800, Steve Longerbeam wrote: >> On 01/13/2017 03:55 AM, Philipp Zabel wrote: >>> Am Freitag, den 06.01.2017, 18:11 -0800 schrieb Steve Longerbeam: >>>> Add bindings documentation for the i.MX media driver. >>>> >>>> Signed-off-by: Steve Longerbeam >>>> --- >>>> Documentation/devicetree/bindings/media/imx.txt | 57 +++++++++++++++++++++++++ >>>> 1 file changed, 57 insertions(+) >>>> create mode 100644 Documentation/devicetree/bindings/media/imx.txt >>>> >>>> diff --git a/Documentation/devicetree/bindings/media/imx.txt b/Documentation/devicetree/bindings/media/imx.txt >>>> new file mode 100644 >>>> index 0000000..254b64a >>>> --- /dev/null >>>> +++ b/Documentation/devicetree/bindings/media/imx.txt >>>> @@ -0,0 +1,57 @@ >>>> +Freescale i.MX Media Video Devices >>>> + >>>> +Video Media Controller node >>>> +--------------------------- >>>> + >>>> +This is the parent media controller node for video capture support. >>>> + >>>> +Required properties: >>>> +- compatible : "fsl,imx-media"; >>> Would you be opposed to calling this "capture-subsystem" instead of >>> "imx-media"? We already use "fsl,imx-display-subsystem" and >>> "fsl,imx-gpu-subsystem" for the display and GPU compound devices. >> sure. Some pie-in-the-sky day when DRM and media are unified, >> there could be a single device that handles them all, > Indeed :) > >> but for now >> I'm fine with "fsl,capture-subsystem". > Actually, I meant fsl,imx-capture-subsystem. right, I caught my error and that is the name chosen. > fsl,imx-media-subsystem > would be fine, too. Either way, I'll be happy if it looks similar to the > other two. > > [...] >>> This is a clever method to get better frame timestamps. Too bad about >>> the routing requirements. Can this be used on Nitrogen6X? >> Absolutely, this support just needs use of the input-capture channels in the >> imx GPT. I still need to submit the patch to the imx-gpt driver that adds an >> input capture API, so at this point fsl,input-capture-channel has no effect, >> but it does work (tested on SabreAuto). > Nice. > > [...] >>>> +Required properties: >>>> +- compatible : "fsl,imx6-mipi-csi2"; >>> I think this should get an additional "snps,dw-mipi-csi2" compatible, >>> since the only i.MX6 specific part is the bolted-on IPU2CSI gasket. >> right, minus the gasket it's a Synopsys core. I'll add that compatible flag. >> Or should wait until the day this subdev is exported for general use, after >> pulling out the gasket specifics? > It can be added right away. ok, I will add. Steve > >>>> +- reg : physical base address and length of the register set; >>>> +- clocks : the MIPI CSI-2 receiver requires three clocks: hsi_tx >>>> + (the DPHY clock), video_27m, and eim_sel; >>> Note that hsi_tx is incorrectly named. CCGR3[CG8] just happens to be the >>> shared gate bit that gates the HSI clocks as well as the MIPI >>> "ac_clk_125m", "cfg_clk", "ips_clk", and "pll_refclk" inputs to the mipi >>> csi-2 core, but we are missing shared gate clocks in the clock tree for >>> these. >> Yes, so many clocks for the MIPI core. Why so many? I would think >> there would need to be at most three: a clock for the MIPI CSI-2 core >> and HSI core, and a clock for the D-PHY (oh and maybe a clock for an >> M-PHY if there is one). I have no clue what all these other clocks are. >> But anyway, a single gating bit, CCGR3[CG8], seems to enable them all. > I would imagine the CSI-2 core has a high-speed clock input from the > D-PHY for serial input, an APB clock for register access (ips_clk), and > a pixel clock input for the parallel output (pixel_clk), at least. > The D-PHY will have a PLL reference input (pll_refclk?) and probably its > own register clock (cfg_clk?). > > I've looked at the MIPI DSI chapter, and it looks like ac_clk_125m is > used for DSI only. > >>> Both cfg_clk and pll_refclk are sourced from video_27m, so "cfg" -> >>> video_27m seems fine. >>> But I don't get "dphy". >> I presume it's the clock for the D-PHY. >> >>> Which input clock would that correspond to? >>> "pll_refclk?" >> the mux at CDCDR says it comes from PLL3_120M, or PLL2_PFD2. > I think that makes sense. > > regards > Philipp > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html