Commit f9d56805 authored by zain wang's avatar zain wang Committed by Heiko Stuebner

drm/bridge: analogix_dp: add fast link train for eDP

We would meet a short black screen when exit PSR with the full link
training, In this case, we should use fast link train instead of full
link training.
Signed-off-by: default avatarzain wang <wzz@rock-chips.com>
Signed-off-by: default avatarSean Paul <seanpaul@chromium.org>
Signed-off-by: default avatarThierry Escande <thierry.escande@collabora.com>
Signed-off-by: default avatarEnric Balletbo i Serra <enric.balletbo@collabora.com>
Tested-by: default avatarMarek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: default avatarArchit Taneja <architt@codeaurora.org>
[dropped header reordering]
Signed-off-by: default avatarHeiko Stuebner <heiko@sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20180309222327.18689-6-enric.balletbo@collabora.com
parent 243e398a
......@@ -15,6 +15,7 @@
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/interrupt.h>
#include <linux/of.h>
#include <linux/of_gpio.h>
......@@ -35,6 +36,8 @@
#define to_dp(nm) container_of(nm, struct analogix_dp_device, nm)
static const bool verify_fast_training;
struct bridge_init {
struct i2c_client *client;
struct device_node *node;
......@@ -528,7 +531,7 @@ static int analogix_dp_process_equalizer_training(struct analogix_dp_device *dp)
{
int lane, lane_count, retval;
u32 reg;
u8 link_align, link_status[2], adjust_request[2];
u8 link_align, link_status[2], adjust_request[2], spread;
usleep_range(400, 401);
......@@ -571,6 +574,20 @@ static int analogix_dp_process_equalizer_training(struct analogix_dp_device *dp)
dev_dbg(dp->dev, "final lane count = %.2x\n",
dp->link_train.lane_count);
retval = drm_dp_dpcd_readb(&dp->aux, DP_MAX_DOWNSPREAD,
&spread);
if (retval != 1) {
dev_err(dp->dev, "failed to read downspread %d\n",
retval);
dp->fast_train_support = false;
} else {
dp->fast_train_support =
(spread & DP_NO_AUX_HANDSHAKE_LINK_TRAINING) ?
true : false;
}
dev_dbg(dp->dev, "fast link training %s\n",
dp->fast_train_support ? "supported" : "unsupported");
/* set enhanced mode if available */
analogix_dp_set_enhanced_mode(dp);
dp->link_train.lt_state = FINISHED;
......@@ -627,10 +644,12 @@ static void analogix_dp_get_max_rx_lane_count(struct analogix_dp_device *dp,
*lane_count = DPCD_MAX_LANE_COUNT(data);
}
static void analogix_dp_init_training(struct analogix_dp_device *dp,
enum link_lane_count_type max_lane,
int max_rate)
static int analogix_dp_full_link_train(struct analogix_dp_device *dp,
u32 max_lanes, u32 max_rate)
{
int retval = 0;
bool training_finished = false;
/*
* MACRO_RST must be applied after the PLL_LOCK to avoid
* the DP inter pair skew issue for at least 10 us
......@@ -656,18 +675,13 @@ static void analogix_dp_init_training(struct analogix_dp_device *dp,
}
/* Setup TX lane count & rate */
if (dp->link_train.lane_count > max_lane)
dp->link_train.lane_count = max_lane;
if (dp->link_train.lane_count > max_lanes)
dp->link_train.lane_count = max_lanes;
if (dp->link_train.link_rate > max_rate)
dp->link_train.link_rate = max_rate;
/* All DP analog module power up */
analogix_dp_set_analog_power_down(dp, POWER_ALL, 0);
}
static int analogix_dp_sw_link_training(struct analogix_dp_device *dp)
{
int retval = 0, training_finished = 0;
dp->link_train.lt_state = START;
......@@ -702,22 +716,88 @@ static int analogix_dp_sw_link_training(struct analogix_dp_device *dp)
return retval;
}
static int analogix_dp_set_link_train(struct analogix_dp_device *dp,
u32 count, u32 bwtype)
static int analogix_dp_fast_link_train(struct analogix_dp_device *dp)
{
int i;
int retval;
int i, ret;
u8 link_align, link_status[2];
enum pll_status status;
for (i = 0; i < DP_TIMEOUT_LOOP_COUNT; i++) {
analogix_dp_init_training(dp, count, bwtype);
retval = analogix_dp_sw_link_training(dp);
if (retval == 0)
break;
analogix_dp_reset_macro(dp);
usleep_range(100, 110);
analogix_dp_set_link_bandwidth(dp, dp->link_train.link_rate);
analogix_dp_set_lane_count(dp, dp->link_train.lane_count);
for (i = 0; i < dp->link_train.lane_count; i++) {
analogix_dp_set_lane_link_training(dp,
dp->link_train.training_lane[i], i);
}
return retval;
ret = readx_poll_timeout(analogix_dp_get_pll_lock_status, dp, status,
status != PLL_UNLOCKED, 120,
120 * DP_TIMEOUT_LOOP_COUNT);
if (ret) {
DRM_DEV_ERROR(dp->dev, "Wait for pll lock failed %d\n", ret);
return ret;
}
/* source Set training pattern 1 */
analogix_dp_set_training_pattern(dp, TRAINING_PTN1);
/* From DP spec, pattern must be on-screen for a minimum 500us */
usleep_range(500, 600);
analogix_dp_set_training_pattern(dp, TRAINING_PTN2);
/* From DP spec, pattern must be on-screen for a minimum 500us */
usleep_range(500, 600);
/* TODO: enhanced_mode?*/
analogix_dp_set_training_pattern(dp, DP_NONE);
/*
* Useful for debugging issues with fast link training, disable for more
* speed
*/
if (verify_fast_training) {
ret = drm_dp_dpcd_readb(&dp->aux, DP_LANE_ALIGN_STATUS_UPDATED,
&link_align);
if (ret < 0) {
DRM_DEV_ERROR(dp->dev, "Read align status failed %d\n",
ret);
return ret;
}
ret = drm_dp_dpcd_read(&dp->aux, DP_LANE0_1_STATUS, link_status,
2);
if (ret < 0) {
DRM_DEV_ERROR(dp->dev, "Read link status failed %d\n",
ret);
return ret;
}
if (analogix_dp_clock_recovery_ok(link_status,
dp->link_train.lane_count)) {
DRM_DEV_ERROR(dp->dev, "Clock recovery failed\n");
analogix_dp_reduce_link_rate(dp);
return -EIO;
}
if (analogix_dp_channel_eq_ok(link_status, link_align,
dp->link_train.lane_count)) {
DRM_DEV_ERROR(dp->dev, "Channel EQ failed\n");
analogix_dp_reduce_link_rate(dp);
return -EIO;
}
}
return 0;
}
static int analogix_dp_train_link(struct analogix_dp_device *dp)
{
if (dp->fast_train_support)
return analogix_dp_fast_link_train(dp);
return analogix_dp_full_link_train(dp, dp->video_info.max_lane_count,
dp->video_info.max_link_rate);
}
static int analogix_dp_config_video(struct analogix_dp_device *dp)
......@@ -846,10 +926,10 @@ static void analogix_dp_commit(struct analogix_dp_device *dp)
DRM_ERROR("failed to disable the panel\n");
}
ret = analogix_dp_set_link_train(dp, dp->video_info.max_lane_count,
dp->video_info.max_link_rate);
ret = readx_poll_timeout(analogix_dp_train_link, dp, ret, !ret, 100,
DP_TIMEOUT_TRAINING_US * 5);
if (ret) {
dev_err(dp->dev, "unable to do link train\n");
dev_err(dp->dev, "unable to do link train, ret=%d\n", ret);
return;
}
......
......@@ -20,6 +20,8 @@
#define MAX_CR_LOOP 5
#define MAX_EQ_LOOP 5
/* Training takes 22ms if AUX channel comm fails. Use this as retry interval */
#define DP_TIMEOUT_TRAINING_US 22000
#define DP_TIMEOUT_PSR_LOOP_MS 300
/* DP_MAX_LANE_COUNT */
......@@ -171,6 +173,7 @@ struct analogix_dp_device {
int hpd_gpio;
bool force_hpd;
bool psr_enable;
bool fast_train_support;
struct mutex panel_lock;
bool panel_is_modeset;
......
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