linux-kernel - [PATCH v5 3/4] drm/bridge: microchip-lvds: add atomic pre_enable() and post

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Message-ID: <20250625-microchip-lvds-v5-3-624cf72b2651@microchip.com>
Date: Wed, 25 Jun 2025 10:26:11 +0530
From: Dharma Balasubiramani <dharma.b@...rochip.com>
To: Manikandan Muralidharan <manikandan.m@...rochip.com>, 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>,
	Simona Vetter <simona@...ll.ch>
CC: <dri-devel@...ts.freedesktop.org>, <linux-kernel@...r.kernel.org>, "Dharma
 Balasubiramani" <dharma.b@...rochip.com>
Subject: [PATCH v5 3/4] drm/bridge: microchip-lvds: add atomic pre_enable()
 and post_disable()

pm_runtime_get_sync() and clk_prepare_enable() must be outside the atomic
context, hence move the sleepable operations accordingly.

- atomic_pre_enable() handles pm_runtime and clock preparation
- atomic_enable() enables the serializer based on panel format
- atomic_disable() turns off the serializer
- atomic_post_disable() disables clock and releases runtime PM

Signed-off-by: Dharma Balasubiramani <dharma.b@...rochip.com>
---
 drivers/gpu/drm/bridge/microchip-lvds.c | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/bridge/microchip-lvds.c b/drivers/gpu/drm/bridge/microchip-lvds.c
index c40c8717f026..b1800f78008c 100644
--- a/drivers/gpu/drm/bridge/microchip-lvds.c
+++ b/drivers/gpu/drm/bridge/microchip-lvds.c
@@ -111,8 +111,8 @@ static int mchp_lvds_attach(struct drm_bridge *bridge,
 				 bridge, flags);
 }
 
-static void mchp_lvds_atomic_enable(struct drm_bridge *bridge,
-				    struct drm_atomic_state *state)
+static void mchp_lvds_atomic_pre_enable(struct drm_bridge *bridge,
+					struct drm_atomic_state *state)
 {
 	struct mchp_lvds *lvds = bridge_to_lvds(bridge);
 	int ret;
@@ -128,7 +128,12 @@ static void mchp_lvds_atomic_enable(struct drm_bridge *bridge,
 		dev_err(lvds->dev, "failed to get pm runtime: %d\n", ret);
 		return;
 	}
+}
 
+static void mchp_lvds_atomic_enable(struct drm_bridge *bridge,
+				    struct drm_atomic_state *state)
+{
+	struct mchp_lvds *lvds = bridge_to_lvds(bridge);
 	lvds_serialiser_on(lvds);
 }
 
@@ -139,6 +144,12 @@ static void mchp_lvds_atomic_disable(struct drm_bridge *bridge,
 
 	/* Turn off the serialiser */
 	lvds_writel(lvds, LVDSC_CR, 0);
+}
+
+static void mchp_lvds_atomic_post_disable(struct drm_bridge *bridge,
+					  struct drm_atomic_state *state)
+{
+	struct mchp_lvds *lvds = bridge_to_lvds(bridge);
 
 	pm_runtime_put(lvds->dev);
 	clk_disable_unprepare(lvds->pclk);
@@ -146,8 +157,10 @@ static void mchp_lvds_atomic_disable(struct drm_bridge *bridge,
 
 static const struct drm_bridge_funcs mchp_lvds_bridge_funcs = {
 	.attach = mchp_lvds_attach,
+	.atomic_pre_enable = mchp_lvds_atomic_pre_enable,
 	.atomic_enable = mchp_lvds_atomic_enable,
 	.atomic_disable = mchp_lvds_atomic_disable,
+	.atomic_post_disable = mchp_lvds_atomic_post_disable,
 };
 
 static int mchp_lvds_probe(struct platform_device *pdev)

-- 
2.43.0