From patchwork Mon Mar 29 13:37:17 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Jani Nikula X-Patchwork-Id: 12170113 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B521EC433C1 for ; Mon, 29 Mar 2021 13:37:50 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 7A0EB6193A for ; Mon, 29 Mar 2021 13:37:50 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7A0EB6193A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 8B4576E40C; Mon, 29 Mar 2021 13:37:49 +0000 (UTC) Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by gabe.freedesktop.org (Postfix) with ESMTPS id 125686E40C; Mon, 29 Mar 2021 13:37:48 +0000 (UTC) IronPort-SDR: IjFT8OcAtq33MHv6V2pc7fQrbgmdX+D73c+vYpctWnQYLCiBHUphERoAY6GA+HL53r+VrS76MV Msp0Mnh6cy1w== X-IronPort-AV: E=McAfee;i="6000,8403,9938"; a="191578929" X-IronPort-AV: E=Sophos;i="5.81,287,1610438400"; d="scan'208";a="191578929" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 Mar 2021 06:37:47 -0700 IronPort-SDR: MxLL1Z5nl/JWIA8KQtWDxVocpAZEOI0xQwcVRqewzwBc6riNJ+QOOCaKsJSp88OJJp3BcFNoPf BnEeztMzHzUQ== X-IronPort-AV: E=Sophos;i="5.81,287,1610438400"; d="scan'208";a="516019793" Received: from auchter-mobl.ger.corp.intel.com (HELO localhost) ([10.252.56.199]) by fmsmga001-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 Mar 2021 06:37:44 -0700 From: Jani Nikula To: dri-devel@lists.freedesktop.org Subject: [PATCH v2 3/8] drm/displayid: add new displayid section/block iterators Date: Mon, 29 Mar 2021 16:37:17 +0300 Message-Id: X-Mailer: git-send-email 2.20.1 In-Reply-To: References: MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Jani Nikula , intel-gfx@lists.freedesktop.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Iterating DisplayID blocks across sections (in EDID extensions) is unnecessarily complicated for the caller. Implement DisplayID iterators to go through all blocks in all sections. Usage example: const struct displayid_block *block; struct displayid_iter iter; displayid_iter_edid_begin(edid, &iter); displayid_iter_for_each(block, &iter) { /* operate on block */ } displayid_iter_end(&iter); When DisplayID is stored in EDID extensions, the DisplayID sections map to extensions as described in VESA DisplayID v1.3 Appendix B: DisplayID as an EDID Extension. This is implemented here. When DisplayID is stored in its dedicated DDC device 0xA4, according to VESA E-DDC v1.3, different rules apply for the structure. This is not implemented here, as we don't currently use it, but the idea is you'd have a different call for beginning the iteration, for example simply: displayid_iter_begin(displayid, &iter); instead of displayid_iter_edid_begin(), and everything else would be hidden away in the iterator functions. v2: - sizeof(struct displayid_block) -> sizeof(*block) (Ville) - remove __ prefix from displayid_iter_block Reviewed-by: Ville Syrjälä Signed-off-by: Jani Nikula --- drivers/gpu/drm/drm_displayid.c | 74 +++++++++++++++++++++++++++++++++ include/drm/drm_displayid.h | 18 ++++++++ 2 files changed, 92 insertions(+) diff --git a/drivers/gpu/drm/drm_displayid.c b/drivers/gpu/drm/drm_displayid.c index 908bbe6feb61..5b809bb9fecc 100644 --- a/drivers/gpu/drm/drm_displayid.c +++ b/drivers/gpu/drm/drm_displayid.c @@ -57,3 +57,77 @@ const u8 *drm_find_displayid_extension(const struct edid *edid, return displayid; } + +void displayid_iter_edid_begin(const struct edid *edid, + struct displayid_iter *iter) +{ + memset(iter, 0, sizeof(*iter)); + + iter->edid = edid; +} + +static const struct displayid_block * +displayid_iter_block(const struct displayid_iter *iter) +{ + const struct displayid_block *block; + + if (!iter->section) + return NULL; + + block = (const struct displayid_block *)&iter->section[iter->idx]; + + if (iter->idx + sizeof(*block) <= iter->length && + iter->idx + sizeof(*block) + block->num_bytes <= iter->length && + block->num_bytes > 0) + return block; + + return NULL; +} + +const struct displayid_block * +__displayid_iter_next(struct displayid_iter *iter) +{ + const struct displayid_block *block; + + if (!iter->edid) + return NULL; + + if (iter->section) { + /* current block should always be valid */ + block = displayid_iter_block(iter); + if (WARN_ON(!block)) { + iter->section = NULL; + iter->edid = NULL; + return NULL; + } + + /* next block in section */ + iter->idx += sizeof(*block) + block->num_bytes; + + block = displayid_iter_block(iter); + if (block) + return block; + } + + for (;;) { + iter->section = drm_find_displayid_extension(iter->edid, + &iter->length, + &iter->idx, + &iter->ext_index); + if (!iter->section) { + iter->edid = NULL; + return NULL; + } + + iter->idx += sizeof(struct displayid_hdr); + + block = displayid_iter_block(iter); + if (block) + return block; + } +} + +void displayid_iter_end(struct displayid_iter *iter) +{ + memset(iter, 0, sizeof(*iter)); +} diff --git a/include/drm/drm_displayid.h b/include/drm/drm_displayid.h index 3c6db22a518a..27e06c98db17 100644 --- a/include/drm/drm_displayid.h +++ b/include/drm/drm_displayid.h @@ -108,4 +108,22 @@ const u8 *drm_find_displayid_extension(const struct edid *edid, int *length, int *idx, int *ext_index); +/* DisplayID iteration */ +struct displayid_iter { + const struct edid *edid; + + const u8 *section; + int length; + int idx; + int ext_index; +}; + +void displayid_iter_edid_begin(const struct edid *edid, + struct displayid_iter *iter); +const struct displayid_block * +__displayid_iter_next(struct displayid_iter *iter); +#define displayid_iter_for_each(__block, __iter) \ + while (((__block) = __displayid_iter_next(__iter))) +void displayid_iter_end(struct displayid_iter *iter); + #endif