[PATCH v8 17/19] drm/mediatek: add hpd debounce
Guillaume Ranquet
granquet at baylibre.com
Fri Feb 18 06:54:35 PST 2022
From: Jitao Shi <jitao.shi at mediatek.com>
Implement the DP HDP debounce described in DP 1.4a 3.3.
Signed-off-by: Jitao Shi <jitao.shi at mediatek.com>
Signed-off-by: Guillaume Ranquet <granquet at baylibre.com>
---
drivers/gpu/drm/mediatek/mtk_dp.c | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)
diff --git a/drivers/gpu/drm/mediatek/mtk_dp.c b/drivers/gpu/drm/mediatek/mtk_dp.c
index 2a3d5f15b651b..fe91ab8b2fd89 100644
--- a/drivers/gpu/drm/mediatek/mtk_dp.c
+++ b/drivers/gpu/drm/mediatek/mtk_dp.c
@@ -178,6 +178,8 @@ struct mtk_dp {
struct device *codec_dev;
u8 connector_eld[MAX_ELD_BYTES];
struct drm_connector *conn;
+ bool need_debounce;
+ struct timer_list debounce_timer;
};
static struct regmap_config mtk_dp_regmap_config = {
@@ -1698,6 +1700,9 @@ static irqreturn_t mtk_dp_hpd_event_thread(int hpd, void *dev)
if (event < 0)
return IRQ_HANDLED;
+ if (mtk_dp->need_debounce && mtk_dp->train_info.cable_plugged_in)
+ msleep(100);
+
if (mtk_dp->drm_dev) {
dev_info(mtk_dp->dev, "drm_helper_hpd_irq_event\n");
drm_helper_hpd_irq_event(mtk_dp->bridge.dev);
@@ -1776,6 +1781,13 @@ static irqreturn_t mtk_dp_hpd_isr_handler(struct mtk_dp *mtk_dp)
}
train_info->cable_state_change = true;
+ if (train_info->cable_state_change) {
+ if (!train_info->cable_plugged_in) {
+ mod_timer(&mtk_dp->debounce_timer, jiffies + msecs_to_jiffies(100) - 1);
+ mtk_dp->need_debounce = false;
+ }
+ }
+
return IRQ_WAKE_THREAD;
}
@@ -2239,6 +2251,13 @@ static const struct drm_bridge_funcs mtk_dp_bridge_funcs = {
.detect = mtk_dp_bdg_detect,
};
+static void mtk_dp_debounce_timer(struct timer_list *t)
+{
+ struct mtk_dp *mtk_dp = from_timer(mtk_dp, t, debounce_timer);
+
+ mtk_dp->need_debounce = true;
+}
+
static int mtk_dp_probe(struct platform_device *pdev)
{
struct mtk_dp *mtk_dp;
@@ -2319,6 +2338,9 @@ static int mtk_dp_probe(struct platform_device *pdev)
else
mtk_dp->bridge.type = DRM_MODE_CONNECTOR_DisplayPort;
+ mtk_dp->need_debounce = true;
+ timer_setup(&mtk_dp->debounce_timer, mtk_dp_debounce_timer, 0);
+
pm_runtime_enable(dev);
pm_runtime_get_sync(dev);
@@ -2332,6 +2354,7 @@ static int mtk_dp_remove(struct platform_device *pdev)
platform_device_unregister(mtk_dp->phy_dev);
mtk_dp_video_mute(mtk_dp, true);
+ del_timer_sync(&mtk_dp->debounce_timer);
pm_runtime_disable(&pdev->dev);
--
2.34.1
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