From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thierry Reding Subject: [PATCH v2 2/4] drm/dp: Add drm_dp_dpcd_read_link_status() Date: Tue, 17 Dec 2013 17:20:05 +0100 Message-ID: <1387297207-7643-3-git-send-email-treding@nvidia.com> References: <1387297207-7643-1-git-send-email-treding@nvidia.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail-bk0-f48.google.com (mail-bk0-f48.google.com [209.85.214.48]) by gabe.freedesktop.org (Postfix) with ESMTP id 68F7CFCD54 for ; Tue, 17 Dec 2013 08:21:37 -0800 (PST) Received: by mail-bk0-f48.google.com with SMTP id r7so2915637bkg.35 for ; Tue, 17 Dec 2013 08:21:36 -0800 (PST) Received: from localhost (port-6309.pppoe.wtnet.de. [84.46.24.189]) by mx.google.com with ESMTPSA id sx5sm13994659bkb.0.2013.12.17.08.21.35 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 17 Dec 2013 08:21:35 -0800 (PST) In-Reply-To: <1387297207-7643-1-git-send-email-treding@nvidia.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dri-devel-bounces@lists.freedesktop.org Errors-To: dri-devel-bounces@lists.freedesktop.org To: dri-devel@lists.freedesktop.org List-Id: dri-devel@lists.freedesktop.org The function reads the link status (6 bytes starting at offset 0x202) from the DPCD so that it can be conveniently passed to other DPCD helpers. Signed-off-by: Thierry Reding --- drivers/gpu/drm/drm_dp_helper.c | 16 ++++++++++++++++ include/drm/drm_dp_helper.h | 3 +++ 2 files changed, 19 insertions(+) diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index bd622d462ca7..8111b8e5a8bc 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -462,3 +462,19 @@ ssize_t drm_dp_dpcd_write(struct drm_dp_aux *aux, unsigned int offset, return -EIO; } EXPORT_SYMBOL(drm_dp_dpcd_write); + +/** + * drm_dp_dpcd_read_link_status() - read DPCD link status (bytes 0x202-0x207) + * @aux: DisplayPort AUX channel + * @status: buffer to store the link status in (must be at least 6 bytes) + * + * Returns the number of bytes transferred on success or a negative error + * code on failure. + */ +int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux, + u8 status[DP_LINK_STATUS_SIZE]) +{ + return drm_dp_dpcd_read(aux, DP_LANE0_1_STATUS, status, + DP_LINK_STATUS_SIZE); +} +EXPORT_SYMBOL(drm_dp_dpcd_read_link_status); diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h index 0b14e799cd98..38cbaef05005 100644 --- a/include/drm/drm_dp_helper.h +++ b/include/drm/drm_dp_helper.h @@ -461,4 +461,7 @@ static inline ssize_t drm_dp_dpcd_writeb(struct drm_dp_aux *aux, u8 value, return drm_dp_dpcd_write(aux, offset, &value, 1); } +int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux, + u8 status[DP_LINK_STATUS_SIZE]); + #endif /* _DRM_DP_HELPER_H_ */ -- 1.8.4.2