linux-kernel - [PATCH 5/9] drm/meson: dw-hdmi: split resets out of hw init.

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Message-ID: <20240730125023.710237-6-jbrunet@baylibre.com>
Date: Tue, 30 Jul 2024 14:50:15 +0200
From: Jerome Brunet <jbrunet@...libre.com>
To: Neil Armstrong <neil.armstrong@...aro.org>,
	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: Jerome Brunet <jbrunet@...libre.com>,
	Kevin Hilman <khilman@...libre.com>,
	Martin Blumenstingl <martin.blumenstingl@...glemail.com>,
	dri-devel@...ts.freedesktop.org,
	linux-amlogic@...ts.infradead.org,
	linux-kernel@...r.kernel.org
Subject: [PATCH 5/9] drm/meson: dw-hdmi: split resets out of hw init.

This prepares the migration to regmap usage.

To properly setup regmap, the APB needs to be in working order.
This is easier handled if the resets are not mixed with hw init.

More checks are required to determine if the resets are needed
on resume or not. Add a note for this.

Signed-off-by: Jerome Brunet <jbrunet@...libre.com>
---
 drivers/gpu/drm/meson/meson_dw_hdmi.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/meson/meson_dw_hdmi.c b/drivers/gpu/drm/meson/meson_dw_hdmi.c
index 5cd3264ab874..47aa3e184e98 100644
--- a/drivers/gpu/drm/meson/meson_dw_hdmi.c
+++ b/drivers/gpu/drm/meson/meson_dw_hdmi.c
@@ -581,11 +581,6 @@ static void meson_dw_hdmi_init(struct meson_dw_hdmi *meson_dw_hdmi)
 	/* Bring HDMITX MEM output of power down */
 	regmap_update_bits(priv->hhi, HHI_MEM_PD_REG0, 0xff << 8, 0);
 
-	/* Reset HDMITX APB & TX & PHY */
-	reset_control_reset(meson_dw_hdmi->hdmitx_apb);
-	reset_control_reset(meson_dw_hdmi->hdmitx_ctrl);
-	reset_control_reset(meson_dw_hdmi->hdmitx_phy);
-
 	/* Enable APB3 fail on error */
 	if (!meson_vpu_is_compatible(priv, VPU_COMPATIBLE_G12A)) {
 		writel_bits_relaxed(BIT(15), BIT(15),
@@ -675,6 +670,10 @@ static int meson_dw_hdmi_bind(struct device *dev, struct device *master,
 		return PTR_ERR(meson_dw_hdmi->hdmitx_phy);
 	}
 
+	reset_control_reset(meson_dw_hdmi->hdmitx_apb);
+	reset_control_reset(meson_dw_hdmi->hdmitx_ctrl);
+	reset_control_reset(meson_dw_hdmi->hdmitx_phy);
+
 	meson_dw_hdmi->hdmitx = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(meson_dw_hdmi->hdmitx))
 		return PTR_ERR(meson_dw_hdmi->hdmitx);
@@ -765,6 +764,11 @@ static int __maybe_unused meson_dw_hdmi_pm_resume(struct device *dev)
 	if (!meson_dw_hdmi)
 		return 0;
 
+	/* TODO: Is this really necessary/desirable on resume ? */
+	reset_control_reset(meson_dw_hdmi->hdmitx_apb);
+	reset_control_reset(meson_dw_hdmi->hdmitx_ctrl);
+	reset_control_reset(meson_dw_hdmi->hdmitx_phy);
+
 	meson_dw_hdmi_init(meson_dw_hdmi);
 
 	dw_hdmi_resume(meson_dw_hdmi->hdmi);
-- 
2.43.0