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Message-Id: <20240319225122.3048400-8-sean.anderson@linux.dev>
Date: Tue, 19 Mar 2024 18:51:20 -0400
From: Sean Anderson <sean.anderson@...ux.dev>
To: Laurent Pinchart <laurent.pinchart@...asonboard.com>,
Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
Maxime Ripard <mripard@...nel.org>,
Thomas Zimmermann <tzimmermann@...e.de>,
dri-devel@...ts.freedesktop.org
Cc: Michal Simek <michal.simek@....com>,
David Airlie <airlied@...il.com>,
linux-kernel@...r.kernel.org,
Daniel Vetter <daniel@...ll.ch>,
linux-arm-kernel@...ts.infradead.org,
Sean Anderson <sean.anderson@...ux.dev>
Subject: [PATCH v2 7/8] drm: zynqmp_dp: Split off several helper functions
In preparation for supporting compliance testing, split off several
helper functions. No functional change intended.
Signed-off-by: Sean Anderson <sean.anderson@...ux.dev>
Reviewed-by: Laurent Pinchart <laurent.pinchart@...asonboard.com>
---
(no changes since v1)
drivers/gpu/drm/xlnx/zynqmp_dp.c | 49 ++++++++++++++++++++++----------
1 file changed, 34 insertions(+), 15 deletions(-)
diff --git a/drivers/gpu/drm/xlnx/zynqmp_dp.c b/drivers/gpu/drm/xlnx/zynqmp_dp.c
index a90ab5c0f5cf..6e04dcf61e19 100644
--- a/drivers/gpu/drm/xlnx/zynqmp_dp.c
+++ b/drivers/gpu/drm/xlnx/zynqmp_dp.c
@@ -633,6 +633,7 @@ static void zynqmp_dp_adjust_train(struct zynqmp_dp *dp,
/**
* zynqmp_dp_update_vs_emph - Update the training values
* @dp: DisplayPort IP core structure
+ * @train_set: A set of training values
*
* Update the training values based on the request from sink. The mapped values
* are predefined, and values(vs, pe, pc) are from the device manual.
@@ -640,12 +641,12 @@ static void zynqmp_dp_adjust_train(struct zynqmp_dp *dp,
* Return: 0 if vs and emph are updated successfully, or the error code returned
* by drm_dp_dpcd_write().
*/
-static int zynqmp_dp_update_vs_emph(struct zynqmp_dp *dp)
+static int zynqmp_dp_update_vs_emph(struct zynqmp_dp *dp, u8 *train_set)
{
unsigned int i;
int ret;
- ret = drm_dp_dpcd_write(&dp->aux, DP_TRAINING_LANE0_SET, dp->train_set,
+ ret = drm_dp_dpcd_write(&dp->aux, DP_TRAINING_LANE0_SET, train_set,
dp->mode.lane_cnt);
if (ret < 0)
return ret;
@@ -653,7 +654,7 @@ static int zynqmp_dp_update_vs_emph(struct zynqmp_dp *dp)
for (i = 0; i < dp->mode.lane_cnt; i++) {
u32 reg = ZYNQMP_DP_SUB_TX_PHY_PRECURSOR_LANE_0 + i * 4;
union phy_configure_opts opts = { 0 };
- u8 train = dp->train_set[i];
+ u8 train = train_set[i];
opts.dp.voltage[0] = (train & DP_TRAIN_VOLTAGE_SWING_MASK)
>> DP_TRAIN_VOLTAGE_SWING_SHIFT;
@@ -697,7 +698,7 @@ static int zynqmp_dp_link_train_cr(struct zynqmp_dp *dp)
* So, This loop should exit before 512 iterations
*/
for (max_tries = 0; max_tries < 512; max_tries++) {
- ret = zynqmp_dp_update_vs_emph(dp);
+ ret = zynqmp_dp_update_vs_emph(dp, dp->train_set);
if (ret)
return ret;
@@ -762,7 +763,7 @@ static int zynqmp_dp_link_train_ce(struct zynqmp_dp *dp)
return ret;
for (tries = 0; tries < DP_MAX_TRAINING_TRIES; tries++) {
- ret = zynqmp_dp_update_vs_emph(dp);
+ ret = zynqmp_dp_update_vs_emph(dp, dp->train_set);
if (ret)
return ret;
@@ -785,28 +786,29 @@ static int zynqmp_dp_link_train_ce(struct zynqmp_dp *dp)
}
/**
- * zynqmp_dp_train - Train the link
+ * zynqmp_dp_setup() - Set up major link parameters
* @dp: DisplayPort IP core structure
+ * @bw_code: The link bandwidth as a multiple of 270 MHz
+ * @lane_cnt: The number of lanes to use
+ * @enhanced: Use enhanced framing
+ * @downspread: Enable spread-spectrum clocking
*
- * Return: 0 if all trains are done successfully, or corresponding error code.
+ * Return: 0 on success, or -errno on failure
*/
-static int zynqmp_dp_train(struct zynqmp_dp *dp)
+static int zynqmp_dp_setup(struct zynqmp_dp *dp, u8 bw_code, u8 lane_cnt,
+ bool enhanced, bool downspread)
{
u32 reg;
- u8 bw_code = dp->mode.bw_code;
- u8 lane_cnt = dp->mode.lane_cnt;
u8 aux_lane_cnt = lane_cnt;
- bool enhanced;
int ret;
zynqmp_dp_write(dp, ZYNQMP_DP_LANE_COUNT_SET, lane_cnt);
- enhanced = drm_dp_enhanced_frame_cap(dp->dpcd);
if (enhanced) {
zynqmp_dp_write(dp, ZYNQMP_DP_ENHANCED_FRAME_EN, 1);
aux_lane_cnt |= DP_LANE_COUNT_ENHANCED_FRAME_EN;
}
- if (dp->dpcd[3] & 0x1) {
+ if (downspread) {
zynqmp_dp_write(dp, ZYNQMP_DP_DOWNSPREAD_CTL, 1);
drm_dp_dpcd_writeb(&dp->aux, DP_DOWNSPREAD_CTRL,
DP_SPREAD_AMP_0_5);
@@ -849,8 +851,25 @@ static int zynqmp_dp_train(struct zynqmp_dp *dp)
}
zynqmp_dp_write(dp, ZYNQMP_DP_PHY_CLOCK_SELECT, reg);
- ret = zynqmp_dp_phy_ready(dp);
- if (ret < 0)
+ return zynqmp_dp_phy_ready(dp);
+}
+
+
+/**
+ * zynqmp_dp_train - Train the link
+ * @dp: DisplayPort IP core structure
+ *
+ * Return: 0 if all trains are done successfully, or corresponding error code.
+ */
+static int zynqmp_dp_train(struct zynqmp_dp *dp)
+{
+ int ret;
+
+ ret = zynqmp_dp_setup(dp, dp->mode.bw_code, dp->mode.lane_cnt,
+ drm_dp_enhanced_frame_cap(dp->dpcd),
+ dp->dpcd[DP_MAX_DOWNSPREAD] &
+ DP_MAX_DOWNSPREAD_0_5);
+ if (ret)
return ret;
zynqmp_dp_write(dp, ZYNQMP_DP_SCRAMBLING_DISABLE, 1);
--
2.35.1.1320.gc452695387.dirty
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