From patchwork Fri Mar 29 02:39:59 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Simon Horman X-Patchwork-Id: 2360731 Return-Path: X-Original-To: patchwork-ltsi-dev@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) by patchwork2.kernel.org (Postfix) with ESMTP id 7AF80DF2A1 for ; Fri, 29 Mar 2013 02:47:44 +0000 (UTC) Received: from mail.linux-foundation.org (localhost [IPv6:::1]) by mail.linuxfoundation.org (Postfix) with ESMTP id DD75FB40; Fri, 29 Mar 2013 02:45:48 +0000 (UTC) X-Original-To: ltsi-dev@lists.linuxfoundation.org Delivered-To: ltsi-dev@mail.linuxfoundation.org Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTP id BCB378A8 for ; Fri, 29 Mar 2013 02:45:45 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from kirsty.vergenet.net (kirsty.vergenet.net [202.4.237.240]) by smtp1.linuxfoundation.org (Postfix) with ESMTP id 84BF01F9A4 for ; Fri, 29 Mar 2013 02:45:44 +0000 (UTC) Received: from ayumi.akashicho.tokyo.vergenet.net (p8120-ipbfp1001kobeminato.hyogo.ocn.ne.jp [118.10.137.120]) by kirsty.vergenet.net (Postfix) with ESMTP id 7E4E82C69D2; Fri, 29 Mar 2013 13:45:34 +1100 (EST) Received: by ayumi.akashicho.tokyo.vergenet.net (Postfix, from userid 7100) id EFBE2EDEA1E; Fri, 29 Mar 2013 11:45:32 +0900 (JST) From: Simon Horman To: ltsi-dev@lists.linuxfoundation.org Date: Fri, 29 Mar 2013 11:39:59 +0900 Message-Id: <1364525119-31791-71-git-send-email-horms+renesas@verge.net.au> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1364525119-31791-1-git-send-email-horms+renesas@verge.net.au> References: <1364525119-31791-1-git-send-email-horms+renesas@verge.net.au> X-Spam-Status: No, score=-3.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_LOW, RP_MATCHES_RCVD autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org Cc: Magnus Damm Subject: [LTSI-dev] [PATCH/RFC 070/390] drm: edid: add support for E-DDC X-BeenThere: ltsi-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: "A list to discuss patches, development, and other things related to the LTSI project" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: ltsi-dev-bounces@lists.linuxfoundation.org Errors-To: ltsi-dev-bounces@lists.linuxfoundation.org From: Shirish S The current logic for probing ddc is limited to 2 blocks (256 bytes), this patch adds support for the 4 block (512) data. To do this, a single 8-bit segment index is passed to the display via the I2C address 30h. Data from the selected segment is then immediately read via the regular DDC2 address using a repeated I2C 'START' signal. Signed-off-by: Shirish S Reviewed-by: Jean Delvare Reviewed-by: Daniel Vetter Reviewed-by: Ville Syrjala Signed-off-by: Dave Airlie (cherry picked from commit cd004b3f4cd4169815c82bf9e424fda06978898a) Signed-off-by: Simon Horman --- drivers/gpu/drm/drm_edid.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c index 47dcd9e..7baa553 100644 --- a/drivers/gpu/drm/drm_edid.c +++ b/drivers/gpu/drm/drm_edid.c @@ -257,6 +257,8 @@ drm_do_probe_ddc_edid(struct i2c_adapter *adapter, unsigned char *buf, int block, int len) { unsigned char start = block * EDID_LENGTH; + unsigned char segment = block >> 1; + unsigned char xfers = segment ? 3 : 2; int ret, retries = 5; /* The core i2c driver will automatically retry the transfer if the @@ -268,6 +270,11 @@ drm_do_probe_ddc_edid(struct i2c_adapter *adapter, unsigned char *buf, do { struct i2c_msg msgs[] = { { + .addr = DDC_SEGMENT_ADDR, + .flags = 0, + .len = 1, + .buf = &segment, + }, { .addr = DDC_ADDR, .flags = 0, .len = 1, @@ -279,15 +286,21 @@ drm_do_probe_ddc_edid(struct i2c_adapter *adapter, unsigned char *buf, .buf = buf, } }; - ret = i2c_transfer(adapter, msgs, 2); + + /* + * Avoid sending the segment addr to not upset non-compliant ddc + * monitors. + */ + ret = i2c_transfer(adapter, &msgs[3 - xfers], xfers); + if (ret == -ENXIO) { DRM_DEBUG_KMS("drm: skipping non-existent adapter %s\n", adapter->name); break; } - } while (ret != 2 && --retries); + } while (ret != xfers && --retries); - return ret == 2 ? 0 : -1; + return ret == xfers ? 0 : -1; } static bool drm_edid_is_zero(u8 *in_edid, int length)