linux-kernel - [PATCH 2/2] drm/bridge: anx7625: Fix Set HPD irq detect window to 2ms

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Message-Id: <20231120091038.284825-2-xji@analogixsemi.com>
Date:   Mon, 20 Nov 2023 17:10:37 +0800
From:   Xin Ji <xji@...logixsemi.com>
To:     Andrzej Hajda <andrzej.hajda@...el.com>,
        Neil Armstrong <neil.armstrong@...aro.org>,
        Robert Foss <rfoss@...nel.org>,
        Laurent Pinchart <Laurent.pinchart@...asonboard.com>,
        Jonas Karlman <jonas@...boo.se>,
        Jernej Skrabec <jernej.skrabec@...il.com>,
        Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
        Maxime Ripard <mripard@...nel.org>,
        Thomas Zimmermann <tzimmermann@...e.de>,
        David Airlie <airlied@...il.com>,
        Daniel Vetter <daniel@...ll.ch>
Cc:     bliang@...logixsemi.com, qwen@...logixsemi.com,
        hsinyi@...omium.org, Xin Ji <xji@...logixsemi.com>,
        dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org
Subject: [PATCH 2/2] drm/bridge: anx7625: Fix Set HPD irq detect window to 2ms

Polling firmware HPD GPIO status, set HPD irq detect window to 2ms
after firmware HPD GPIO initial done

Signed-off-by: Xin Ji <xji@...logixsemi.com>
---
 drivers/gpu/drm/bridge/analogix/anx7625.c | 51 ++++++++++++++++-------
 drivers/gpu/drm/bridge/analogix/anx7625.h |  4 ++
 2 files changed, 40 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/drm/bridge/analogix/anx7625.c b/drivers/gpu/drm/bridge/analogix/anx7625.c
index 51abe42c639e..ef31033439bc 100644
--- a/drivers/gpu/drm/bridge/analogix/anx7625.c
+++ b/drivers/gpu/drm/bridge/analogix/anx7625.c
@@ -1298,10 +1298,32 @@ static void anx7625_config(struct anx7625_data *ctx)
 			  XTAL_FRQ_SEL, XTAL_FRQ_27M);
 }
 
+static int anx7625_hpd_timer_config(struct anx7625_data *ctx)
+{
+	int ret;
+
+	/* Set irq detect window to 2ms */
+	ret = anx7625_reg_write(ctx, ctx->i2c.tx_p2_client,
+				HPD_DET_TIMER_BIT0_7, HPD_TIME & 0xFF);
+	ret |= anx7625_reg_write(ctx, ctx->i2c.tx_p2_client,
+				 HPD_DET_TIMER_BIT8_15,
+				 (HPD_TIME >> 8) & 0xFF);
+	ret |= anx7625_reg_write(ctx, ctx->i2c.tx_p2_client,
+				 HPD_DET_TIMER_BIT16_23,
+				 (HPD_TIME >> 16) & 0xFF);
+
+	return ret;
+}
+
+static int anx7625_read_hpd_gpio_config_status(struct anx7625_data *ctx)
+{
+	return anx7625_reg_read(ctx, ctx->i2c.rx_p0_client, GPIO_CTRL_2);
+}
+
 static void anx7625_disable_pd_protocol(struct anx7625_data *ctx)
 {
 	struct device *dev = ctx->dev;
-	int ret;
+	int ret, val;
 
 	/* Reset main ocm */
 	ret = anx7625_reg_write(ctx, ctx->i2c.rx_p0_client, 0x88, 0x40);
@@ -1315,6 +1337,19 @@ static void anx7625_disable_pd_protocol(struct anx7625_data *ctx)
 		DRM_DEV_DEBUG_DRIVER(dev, "disable PD feature fail.\n");
 	else
 		DRM_DEV_DEBUG_DRIVER(dev, "disable PD feature succeeded.\n");
+
+	/*
+	 * Make sure the HPD GPIO already be configured after OCM release before
+	 * setting HPD detect window register. Here we poll the status register
+	 * at maximum 40ms, then config HPD irq detect window register
+	 */
+	readx_poll_timeout(anx7625_read_hpd_gpio_config_status,
+			   ctx, val,
+			   ((val & HPD_SOURCE) || (val < 0)),
+			   2000, 2000 * 20);
+
+	/* Set HPD irq detect window to 2ms */
+	anx7625_hpd_timer_config(ctx);
 }
 
 static int anx7625_ocm_loading_check(struct anx7625_data *ctx)
@@ -1437,20 +1472,6 @@ static void anx7625_start_dp_work(struct anx7625_data *ctx)
 
 static int anx7625_read_hpd_status_p0(struct anx7625_data *ctx)
 {
-	int ret;
-
-	/* Set irq detect window to 2ms */
-	ret = anx7625_reg_write(ctx, ctx->i2c.tx_p2_client,
-				HPD_DET_TIMER_BIT0_7, HPD_TIME & 0xFF);
-	ret |= anx7625_reg_write(ctx, ctx->i2c.tx_p2_client,
-				 HPD_DET_TIMER_BIT8_15,
-				 (HPD_TIME >> 8) & 0xFF);
-	ret |= anx7625_reg_write(ctx, ctx->i2c.tx_p2_client,
-				 HPD_DET_TIMER_BIT16_23,
-				 (HPD_TIME >> 16) & 0xFF);
-	if (ret < 0)
-		return ret;
-
 	return anx7625_reg_read(ctx, ctx->i2c.rx_p0_client, SYSTEM_STSTUS);
 }
 
diff --git a/drivers/gpu/drm/bridge/analogix/anx7625.h b/drivers/gpu/drm/bridge/analogix/anx7625.h
index 5af819611ebc..66ebee7f3d83 100644
--- a/drivers/gpu/drm/bridge/analogix/anx7625.h
+++ b/drivers/gpu/drm/bridge/analogix/anx7625.h
@@ -259,6 +259,10 @@
 #define AP_MIPI_RX_EN BIT(5) /* 1: MIPI RX input in  0: no RX in */
 #define AP_DISABLE_PD BIT(6)
 #define AP_DISABLE_DISPLAY BIT(7)
+
+#define GPIO_CTRL_2   0x49
+#define HPD_SOURCE    BIT(6)
+
 /***************************************************************/
 /* Register definition of device address 0x84 */
 #define  MIPI_PHY_CONTROL_3            0x03
-- 
2.25.1