drm/vc4: hdmi: Move HDMI reset to pm_resume

The BCM2835-37 found in the RaspberryPi 0 to 3 have a power domain
attached to the HDMI block, handled in Linux through runtime_pm.

That power domain is shared with the VEC block, so even if we put our
runtime_pm reference in the HDMI driver it would keep being on. If the
VEC is disabled though, the power domain would be disabled and we would
lose any initialization done in our bind implementation.

That initialization involves calling the reset function and initializing
the CEC registers.

Let's move the initialization to our runtime_resume implementation so
that we initialize everything properly if we ever need to.

Fixes: c86b4121 ("drm/vc4: hdmi: Move the HSM clock enable to runtime_pm")
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Link: https://lore.kernel.org/r/20220613144800.326124-24-maxime@cerno.techSigned-off-by: Maxime Ripard <maxime@cerno.tech>

drivers/gpu/drm/vc4/vc4_hdmi.c

@@ -2544,8 +2544,6 @@ static int vc4_hdmi_cec_init(struct vc4_hdmi *vc4_hdmi)
 	struct cec_connector_info conn_info;
 	struct platform_device *pdev = vc4_hdmi->pdev;
 	struct device *dev = &pdev->dev;
-	unsigned long flags;
-	u32 value;
 	int ret;
 
 	if (!of_find_property(dev->of_node, "interrupts", NULL)) {
@@ -2564,15 +2562,6 @@ static int vc4_hdmi_cec_init(struct vc4_hdmi *vc4_hdmi)
 	cec_fill_conn_info_from_drm(&conn_info, &vc4_hdmi->connector);
 	cec_s_conn_info(vc4_hdmi->cec_adap, &conn_info);
 
-	spin_lock_irqsave(&vc4_hdmi->hw_lock, flags);
-	value = HDMI_READ(HDMI_CEC_CNTRL_1);
-	/* Set the logical address to Unregistered */
-	value |= VC4_HDMI_CEC_ADDR_MASK;
-	HDMI_WRITE(HDMI_CEC_CNTRL_1, value);
-	spin_unlock_irqrestore(&vc4_hdmi->hw_lock, flags);
-
-	vc4_hdmi_cec_update_clk_div(vc4_hdmi);
-
 	if (vc4_hdmi->variant->external_irq_controller) {
 		ret = request_threaded_irq(platform_get_irq_byname(pdev, "cec-rx"),
 					   vc4_cec_irq_handler_rx_bare,
@@ -2588,10 +2577,6 @@ static int vc4_hdmi_cec_init(struct vc4_hdmi *vc4_hdmi)
 		if (ret)
 			goto err_remove_cec_rx_handler;
 	} else {
-		spin_lock_irqsave(&vc4_hdmi->hw_lock, flags);
-		HDMI_WRITE(HDMI_CEC_CPU_MASK_SET, 0xffffffff);
-		spin_unlock_irqrestore(&vc4_hdmi->hw_lock, flags);
-
 		ret = request_threaded_irq(platform_get_irq(pdev, 0),
 					   vc4_cec_irq_handler,
 					   vc4_cec_irq_handler_thread, 0,
@@ -2642,7 +2627,6 @@ static int vc4_hdmi_cec_init(struct vc4_hdmi *vc4_hdmi)
 }
 
 static void vc4_hdmi_cec_exit(struct vc4_hdmi *vc4_hdmi) {};
-
 #endif
 
 static int vc4_hdmi_build_regset(struct vc4_hdmi *vc4_hdmi,
@@ -2871,12 +2855,34 @@ static int __maybe_unused vc4_hdmi_runtime_suspend(struct device *dev)
 static int vc4_hdmi_runtime_resume(struct device *dev)
 {
 	struct vc4_hdmi *vc4_hdmi = dev_get_drvdata(dev);
+	unsigned long __maybe_unused flags;
+	u32 __maybe_unused value;
 	int ret;
 
 	ret = clk_prepare_enable(vc4_hdmi->hsm_clock);
 	if (ret)
 		return ret;
 
+	if (vc4_hdmi->variant->reset)
+		vc4_hdmi->variant->reset(vc4_hdmi);
+
+#ifdef CONFIG_DRM_VC4_HDMI_CEC
+	spin_lock_irqsave(&vc4_hdmi->hw_lock, flags);
+	value = HDMI_READ(HDMI_CEC_CNTRL_1);
+	/* Set the logical address to Unregistered */
+	value |= VC4_HDMI_CEC_ADDR_MASK;
+	HDMI_WRITE(HDMI_CEC_CNTRL_1, value);
+	spin_unlock_irqrestore(&vc4_hdmi->hw_lock, flags);
+
+	vc4_hdmi_cec_update_clk_div(vc4_hdmi);
+
+	if (!vc4_hdmi->variant->external_irq_controller) {
+		spin_lock_irqsave(&vc4_hdmi->hw_lock, flags);
+		HDMI_WRITE(HDMI_CEC_CPU_MASK_SET, 0xffffffff);
+		spin_unlock_irqrestore(&vc4_hdmi->hw_lock, flags);
+	}
+#endif
+
 	return 0;
 }
 
@@ -2966,9 +2972,6 @@ static int vc4_hdmi_bind(struct device *dev, struct device *master, void *data)
 	pm_runtime_set_active(dev);
 	pm_runtime_enable(dev);
 
-	if (vc4_hdmi->variant->reset)
-		vc4_hdmi->variant->reset(vc4_hdmi);
-
 	if ((of_device_is_compatible(dev->of_node, "brcm,bcm2711-hdmi0") ||
 	     of_device_is_compatible(dev->of_node, "brcm,bcm2711-hdmi1")) &&
 	    HDMI_READ(HDMI_VID_CTL) & VC4_HD_VID_CTL_ENABLE) {