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From: Thierry Reding <thierry.reding@gmail.com>
To: dri-devel@lists.freedesktop.org
Subject: [PATCH v2 06/21] drm/dp: Probe link using existing parsing helpers
Date: Mon,  2 Sep 2019 13:31:06 +0200	[thread overview]
Message-ID: <20190902113121.31323-7-thierry.reding@gmail.com> (raw)
In-Reply-To: <20190902113121.31323-1-thierry.reding@gmail.com>

From: Thierry Reding <treding@nvidia.com>

Use existing parsing helpers to probe a DisplayPort link.

Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Thierry Reding <treding@nvidia.com>
---
 drivers/gpu/drm/drm_dp_helper.c | 29 ++++++++++++++++++++++-------
 include/drm/drm_dp_helper.h     |  2 ++
 2 files changed, 24 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index bdf999bb6cfa..cdf49e8d5e3a 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -320,6 +320,22 @@ ssize_t drm_dp_dpcd_write(struct drm_dp_aux *aux, unsigned int offset,
 }
 EXPORT_SYMBOL(drm_dp_dpcd_write);
 
+/**
+ * drm_dp_dpcd_read_link_caps() - read DPCD link capabilities
+ * @aux: DisplayPort AUX channel
+ * @caps: buffer to store the link capabilities in
+ *
+ * Returns:
+ * The number of bytes transferred on success or a negative error code on
+ * failure.
+ */
+int drm_dp_dpcd_read_link_caps(struct drm_dp_aux *aux,
+			       u8 caps[DP_RECEIVER_CAP_SIZE])
+{
+	return drm_dp_dpcd_read(aux, DP_DPCD_REV, caps, DP_RECEIVER_CAP_SIZE);
+}
+EXPORT_SYMBOL(drm_dp_dpcd_read_link_caps);
+
 /**
  * drm_dp_dpcd_read_link_status() - read DPCD link status (bytes 0x202-0x207)
  * @aux: DisplayPort AUX channel
@@ -376,21 +392,20 @@ static void drm_dp_link_reset(struct drm_dp_link *link)
  */
 int drm_dp_link_probe(struct drm_dp_aux *aux, struct drm_dp_link *link)
 {
-	u8 values[3];
+	u8 values[DP_RECEIVER_CAP_SIZE];
 	int err;
 
 	drm_dp_link_reset(link);
 
-	err = drm_dp_dpcd_read(aux, DP_DPCD_REV, values, sizeof(values));
+	err = drm_dp_dpcd_read_link_caps(aux, values);
 	if (err < 0)
 		return err;
 
-	link->revision = values[0];
-	link->max_rate = drm_dp_bw_code_to_link_rate(values[1]);
-	link->max_lanes = values[2] & DP_MAX_LANE_COUNT_MASK;
+	link->revision = values[DP_DPCD_REV];
+	link->max_rate = drm_dp_max_link_rate(values);
+	link->max_lanes = drm_dp_max_lane_count(values);
 
-	if (values[2] & DP_ENHANCED_FRAME_CAP)
-		link->caps.enhanced_framing = true;
+	link->caps.enhanced_framing = drm_dp_enhanced_frame_cap(values);
 
 	link->rate = link->max_rate;
 	link->lanes = link->max_lanes;
diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
index 2759f8d7e90d..60bb030c858d 100644
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -1350,6 +1350,8 @@ static inline ssize_t drm_dp_dpcd_writeb(struct drm_dp_aux *aux,
 	return drm_dp_dpcd_write(aux, offset, &value, 1);
 }
 
+int drm_dp_dpcd_read_link_caps(struct drm_dp_aux *aux,
+			       u8 caps[DP_RECEIVER_CAP_SIZE]);
 int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux,
 				 u8 status[DP_LINK_STATUS_SIZE]);
 
-- 
2.22.0

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  parent reply	other threads:[~2019-09-02 11:31 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-09-02 11:31 [PATCH v2 00/21] drm/dp: Various helper improvements and cleanups Thierry Reding
2019-09-02 11:31 ` [PATCH v2 01/21] drm/dp: Sort includes alphabetically Thierry Reding
2019-09-02 11:31 ` [PATCH v2 02/21] drm/dp: Add missing kerneldoc for struct drm_dp_link Thierry Reding
2019-09-02 11:31 ` [PATCH v2 03/21] drm/dp: Add drm_dp_link_reset() implementation Thierry Reding
2019-09-02 11:31 ` [PATCH v2 04/21] drm/dp: Track link capabilities alongside settings Thierry Reding
2019-09-02 11:31 ` [PATCH v2 05/21] drm/dp: Turn link capabilities into booleans Thierry Reding
2019-09-02 11:31 ` Thierry Reding [this message]
2019-09-02 11:31 ` [PATCH v2 07/21] drm/dp: Read fast training capability from link Thierry Reding
2019-09-02 11:31 ` [PATCH v2 08/21] drm/dp: Read TPS3 capability from sink Thierry Reding
2019-09-02 11:31 ` [PATCH v2 09/21] drm/dp: Read channel coding " Thierry Reding
2019-09-02 11:31 ` [PATCH v2 10/21] drm/dp: Read alternate scrambler reset " Thierry Reding
2019-09-02 11:31 ` [PATCH v2 11/21] drm/dp: Read eDP version from DPCD Thierry Reding
2019-09-02 11:31 ` [PATCH v2 12/21] drm/dp: Read AUX read interval " Thierry Reding
2019-09-02 11:31 ` [PATCH v2 13/21] drm/dp: Do not busy-loop during link training Thierry Reding
2019-09-02 11:31 ` [PATCH v2 14/21] drm/dp: Use drm_dp_aux_rd_interval() Thierry Reding
2019-09-02 11:31 ` [PATCH v2 15/21] drm/dp: Add helper to get post-cursor adjustments Thierry Reding
2019-09-02 11:31 ` [PATCH v2 16/21] drm/dp: Set channel coding on link configuration Thierry Reding
2019-09-02 11:31 ` [PATCH v2 17/21] drm/dp: Enable alternate scrambler reset when supported Thierry Reding
2019-09-02 11:31 ` [PATCH v2 18/21] drm/dp: Add drm_dp_link_choose() helper Thierry Reding
2019-09-02 11:31 ` [PATCH v2 19/21] drm/dp: Add support for eDP link rates Thierry Reding
2019-09-02 11:31 ` [PATCH v2 20/21] drm/dp: Remove a gratuituous blank line Thierry Reding
2019-09-02 11:31 ` [PATCH v2 21/21] drm/bridge: tc358767: Use DP nomenclature Thierry Reding
2019-09-20 16:00 ` [PATCH v2 00/21] drm/dp: Various helper improvements and cleanups Thierry Reding
2019-09-23 13:52   ` Jani Nikula
2019-09-23 14:52     ` Thierry Reding
2019-10-02 16:14       ` Thierry Reding
2019-10-08  9:42         ` Daniel Vetter
2019-10-08 23:05   ` Lyude Paul

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