From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from pandora.armlinux.org.uk ([78.32.30.218]:56686 "EHLO pandora.armlinux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751073AbdBHXxF (ORCPT ); Wed, 8 Feb 2017 18:53:05 -0500 Date: Wed, 8 Feb 2017 23:42:35 +0000 From: Russell King - ARM Linux To: Steve Longerbeam Cc: Philipp Zabel , robh+dt@kernel.org, mark.rutland@arm.com, shawnguo@kernel.org, kernel@pengutronix.de, fabio.estevam@nxp.com, mchehab@kernel.org, hverkuil@xs4all.nl, nick@shmanahar.org, markus.heiser@darmarIT.de, laurent.pinchart+renesas@ideasonboard.com, bparrot@ti.com, geert@linux-m68k.org, arnd@arndb.de, sudipm.mukherjee@gmail.com, minghsiu.tsai@mediatek.com, tiffany.lin@mediatek.com, jean-christophe.trotin@st.com, horms+renesas@verge.net.au, niklas.soderlund+renesas@ragnatech.se, robert.jarzmik@free.fr, songjun.wu@microchip.com, andrew-ct.chen@mediatek.com, gregkh@linuxfoundation.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-media@vger.kernel.org, devel@driverdev.osuosl.org, Steve Longerbeam Subject: Re: [PATCH v3 21/24] media: imx: Add MIPI CSI-2 Receiver subdev driver Message-ID: <20170208234235.GA27312@n2100.armlinux.org.uk> References: <1483755102-24785-1-git-send-email-steve_longerbeam@mentor.com> <1483755102-24785-22-git-send-email-steve_longerbeam@mentor.com> <1486036237.2289.37.camel@pengutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-media-owner@vger.kernel.org List-ID: On Wed, Feb 08, 2017 at 03:23:53PM -0800, Steve Longerbeam wrote: > >Actually, this exact function already exists as dw_mipi_dsi_phy_write in > >drivers/gpu/drm/rockchip/dw-mipi-dsi.c, and it looks like the D-PHY > >register 0x44 might contain a field called HSFREQRANGE_SEL. > > Thanks for pointing out drivers/gpu/drm/rockchip/dw-mipi-dsi.c. > It's clear from that driver that there probably needs to be a fuller > treatment of the D-PHY programming here, but I don't know where > to find the MIPI CSI-2 D-PHY documentation for the i.MX6. The code > in imxcsi2_reset() was also pulled from FSL, and that's all I really have > to go on for the D-PHY programming. I assume the D-PHY is also a > Synopsys core, like the host controller, but the i.MX6 manual doesn't > cover it. Why exactly? What problems are you seeing that would necessitate a more detailed programming of the D-PHY? From my testing, I can wind a 2-lane MIPI bus on iMX6D from 912Mbps per lane down to (eg) 308Mbps per lane with your existing code without any issues. -- RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up according to speedtest.net.