From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tomasz Stanislawski Subject: Re: [PATCH v4 14/34] drm/exynos: hdmi: remove the i2c drivers and use devtree Date: Fri, 04 Apr 2014 16:04:22 +0200 Message-ID: <533EBBE6.9080604@samsung.com> References: <1391116773-28471-1-git-send-email-seanpaul@chromium.org> <1391116773-28471-15-git-send-email-seanpaul@chromium.org> <52FE2484.2090509@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mailout3.w1.samsung.com (mailout3.w1.samsung.com [210.118.77.13]) by gabe.freedesktop.org (Postfix) with ESMTP id 9249C6ED90 for ; Fri, 4 Apr 2014 07:04:32 -0700 (PDT) Received: from eucpsbgm1.samsung.com (unknown [203.254.199.244]) by mailout3.w1.samsung.com (Oracle Communications Messaging Server 7u4-24.01(7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0N3I00D6OF3J2OA0@mailout3.w1.samsung.com> for dri-devel@lists.freedesktop.org; Fri, 04 Apr 2014 15:04:31 +0100 (BST) In-reply-to: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: Inki Dae Cc: =?ISO-8859-1?Q?St=E9phane_Marchesin?= , DRI mailing list List-Id: dri-devel@lists.freedesktop.org Hi Inki, Sorry for a very late reply. On 02/19/2014 12:14 PM, Inki Dae wrote: > Hi Tomasz, > > > 2014-02-14 23:13 GMT+09:00 Tomasz Stanislawski : >> Hi Daniel, >> I think that it would be better to change the semantic of phy and ddc >> bindings. >> >> Rather than pointing to I2C client it should point to I2C bus instead. >> The exynos DRM driver can create dummy I2C clients using i2c_new_dummy() >> function. > > It seems better way. As of now, all we need for HDMI DDC is > i2c_adapter (including i2c phy), not i2c_client. > >> >> There is quite strong rationale for this: >> - DDC is always accessible on fixed addresses described in HDMI specification. >> - HDMIPHY (including I2C address) is a part of HDMI IP and it is bound to >> specific version of Exynos SoC >> - no need to add virtual nodes in DTS > > You mean hdmiddc and hdmiphy nodes? If so, I think they are real > nodes, not virtual nodes. Otherwise, plz give me more comments. > > Thanks, > Inki Dae > The problem is that those nodes have no dedicated driver. Moreover, the I2C address for HDMIPHY is always present on a fixed address dependant on SoC (read HDMI IP) version. Moreover, both devices share HDMI and HDMIPHY share registers from HDMI's pool. Additionally, the hdmiphy I2C client is currently configured using exynos-hdmi code its DRM driver. So technically the hdmiphy bus is only a resource used by exynos-drm-hdmi driver. Regards, Tomasz Stanislawski >> - NVIDIA already use bindings to DDC bus instead of DDC client. Take a look to >> arch/arm/boot/dts/tegra*.dts >> >> Regards, >> Tomasz Stanislawski >> >> _______________________________________________ >> dri-devel mailing list >> dri-devel@lists.freedesktop.org >> http://lists.freedesktop.org/mailman/listinfo/dri-devel