From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sean Cross Subject: DRM encoder/bridge architecture questions Date: Mon, 18 Aug 2014 16:29:24 +0800 Message-ID: <53F1B964.3080708@kosagi.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail1.g1.pair.com (mail1.g1.pair.com [66.39.3.162]) by gabe.freedesktop.org (Postfix) with ESMTP id 00D6C6E338 for ; Mon, 18 Aug 2014 01:37:50 -0700 (PDT) Received: from [10.0.239.15] (unknown [210.23.18.169]) by mail1.g1.pair.com (Postfix) with ESMTPSA id 36BDA2C187 for ; Mon, 18 Aug 2014 04:29:27 -0400 (EDT) List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: dri-devel@lists.freedesktop.org List-Id: dri-devel@lists.freedesktop.org Hi, We've got an IT6251 LVDS -> eDP bridge chip we're hanging off of a dual-lane LVDS port on an i.MX6. We have a driver we're using internally that's little more than a series of register pokes to boot the chip, but I'd like to clean it up for submission. What kind of device is this? It's externally connected to the main SoC via LVDS and I2C. It's conceptually hanging off of the ldb "LVDS Display Bridge" encoder, which means it's an encoder attached to an encoder. Is that allowed in the DRM model? With the current driver, I have it just sitting in drivers/gpu/drm/i2c/, and it's not "attached" to anything. The encoder chip automatically figures out display timings and the like. Where should the file actually go? Finally, how would the driver get attached to the system? I see there's an Exynos bridge device that appears to go the other way, but it's explicitly loaded by the Exynos display adapter. Since most devices will have an LVDS panel attached directly to the LDB port, it seems silly to have it explicitly look for an additional bridge device to plug in as this is a special case. Is there any way I could pass the it6251 a handle to the ldb in device tree and have it hang itselff of the end that way? Sean