drm/vc4: hdmi: Add PHY init and disable function

The HDMI PHY in the BCM2711 HDMI controller is significantly more
complicated to setup than in the older BCM283x SoCs.

Let's add hooks to enable and disable the PHY.
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Tested-by: Chanwoo Choi <cw00.choi@samsung.com>
Tested-by: Hoegeun Kwon <hoegeun.kwon@samsung.com>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Link: https://patchwork.freedesktop.org/patch/msgid/7216826284dbc60a58bdacd662805d20699e5c80.1599120059.git-series.maxime@cerno.tech

drivers/gpu/drm/vc4/Makefile

@@ -12,6 +12,7 @@ vc4-y := \
 	vc4_kms.o \
 	vc4_gem.o \
 	vc4_hdmi.o \
+	vc4_hdmi_phy.o \
 	vc4_vec.o \
 	vc4_hvs.o \
 	vc4_irq.o \

drivers/gpu/drm/vc4/vc4_hdmi.c

@@ -321,7 +321,9 @@ static void vc4_hdmi_encoder_disable(struct drm_encoder *encoder)
 
 	HDMI_WRITE(HDMI_RAM_PACKET_CONFIG, 0);
 
-	HDMI_WRITE(HDMI_TX_PHY_RESET_CTL, 0xf << 16);
+	if (vc4_hdmi->variant->phy_disable)
+		vc4_hdmi->variant->phy_disable(vc4_hdmi);
+
 	HDMI_WRITE(HDMI_VID_CTL,
 		   HDMI_READ(HDMI_VID_CTL) & ~VC4_HD_VID_CTL_ENABLE);
 
@@ -381,12 +383,8 @@ static void vc4_hdmi_encoder_enable(struct drm_encoder *encoder)
 	if (vc4_hdmi->variant->reset)
 		vc4_hdmi->variant->reset(vc4_hdmi);
 
-	/* PHY should be in reset, like
-	 * vc4_hdmi_encoder_disable() does.
-	 */
-	HDMI_WRITE(HDMI_TX_PHY_RESET_CTL, 0xf << 16);
-
-	HDMI_WRITE(HDMI_TX_PHY_RESET_CTL, 0);
+	if (vc4_hdmi->variant->phy_init)
+		vc4_hdmi->variant->phy_init(vc4_hdmi, mode);
 
 	if (debug_dump_regs) {
 		struct drm_printer p = drm_info_printer(&vc4_hdmi->pdev->dev);
@@ -1432,6 +1430,8 @@ static const struct vc4_hdmi_variant bcm2835_variant = {
 
 	.init_resources		= vc4_hdmi_init_resources,
 	.reset			= vc4_hdmi_reset,
+	.phy_init		= vc4_hdmi_phy_init,
+	.phy_disable		= vc4_hdmi_phy_disable,
 };
 
 static const struct of_device_id vc4_hdmi_dt_match[] = {

drivers/gpu/drm/vc4/vc4_hdmi.h

@@ -21,6 +21,8 @@ to_vc4_hdmi_encoder(struct drm_encoder *encoder)
 	return container_of(encoder, struct vc4_hdmi_encoder, base.base);
 }
 
+struct drm_display_mode;
+
 struct vc4_hdmi;
 struct vc4_hdmi_register;
 
@@ -38,6 +40,13 @@ struct vc4_hdmi_variant {
 
 	/* Callback to reset the HDMI block */
 	void (*reset)(struct vc4_hdmi *vc4_hdmi);
+
+	/* Callback to initialize the PHY according to the mode */
+	void (*phy_init)(struct vc4_hdmi *vc4_hdmi,
+			 struct drm_display_mode *mode);
+
+	/* Callback to disable the PHY */
+	void (*phy_disable)(struct vc4_hdmi *vc4_hdmi);
 };
 
 /* HDMI audio information */
@@ -95,4 +104,8 @@ encoder_to_vc4_hdmi(struct drm_encoder *encoder)
 	return container_of(_encoder, struct vc4_hdmi, encoder);
 }
 
+void vc4_hdmi_phy_init(struct vc4_hdmi *vc4_hdmi,
+		       struct drm_display_mode *mode);
+void vc4_hdmi_phy_disable(struct vc4_hdmi *vc4_hdmi);
+
 #endif /* _VC4_HDMI_H_ */

drivers/gpu/drm/vc4/vc4_hdmi_phy.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2015 Broadcom
+ * Copyright (c) 2014 The Linux Foundation. All rights reserved.
+ * Copyright (C) 2013 Red Hat
+ * Author: Rob Clark <robdclark@gmail.com>
+ */
+
+#include "vc4_hdmi.h"
+#include "vc4_hdmi_regs.h"
+
+void vc4_hdmi_phy_init(struct vc4_hdmi *vc4_hdmi, struct drm_display_mode *mode)
+{
+	/* PHY should be in reset, like
+	 * vc4_hdmi_encoder_disable() does.
+	 */
+
+	HDMI_WRITE(HDMI_TX_PHY_RESET_CTL, 0xf << 16);
+	HDMI_WRITE(HDMI_TX_PHY_RESET_CTL, 0);
+}
+
+void vc4_hdmi_phy_disable(struct vc4_hdmi *vc4_hdmi)
+{
+	HDMI_WRITE(HDMI_TX_PHY_RESET_CTL, 0xf << 16);
+}